Categorisation of complications and validation of the Clavien score for percutaneous nephrolithotomy

Does the suturing technique (barbed continuous versus conventional interrupted) impact the outcome of anastomotic urethroplasty?

PURPOSE

To evaluate and compare continuous suture (CS) and interrupted suture (IS) techniques applied in excision and primary anastomosis (EPA) urethroplasty in terms of surgical success and complication rates.

METHODS

A retrospective evaluation was conducted on patients with bulbar urethral strictures measuring ≤ 2.5 cm who underwent EPA between April 2020 and December 2022. Patients with a history of urethral reconstruction, multiple strictures, a history of pelvic radiotherapy, a diagnosis of Lichen sclerosis, a history of surgery due to congenital penile curvature or Peyronie's disease, and a follow-up period of less than 12 months were excluded. The patients were divided into two groups according to the suture technique used (CS or IS), and the groups were compared for demographic and perioperative data.

RESULTS

A total of 97 patients (CS n = 52, IS n = 55) were included in the sample. The mean age of the entire patient group was calculated to be 56.2 years and the mean stricture length was 19.3 mm. Operation time and postoperative catheter time were shorter in the CS group (94.7 ± 7.3 vs. 117.2 ± 5.7 min and 9.9 ± 1.6 vs. 15.8 ± 1.9 min, p < 0.001, respectively). The groups were similar regarding anatomical success, stress urinary incontinence, penile numbness, curvature, and postoperative infection (p > 0.05).

CONCLUSION

No significant difference was observed in terms of success or complications between the CS and IS techniques employed during EPA urethroplasty. However, in addition to reducing the operation time, the CS technique offers the advantage of safely removing the urethral catheter earlier.

Optimizing Colon Identification by Window Setting Modulation on Noncontrast Computed Tomography Prior to Percutaneous Nephrolithotomy

Background: Preoperative identification of the bowel on imaging is essential in planning renal access during percutaneous nephrolithotomy (PCNL) and avoiding colonic injury. We aimed this study to assess which noncontrast computed tomography (NCCT) window setting provides the optimal colonic identification for PCNL preoperative planning. Methods: Ten urologic surgeons (four seniors, six residents) reviewed 22 images of NCCT scans in both abdomen and lung window settings in a randomized blinded order. Colonic area delineation in each image was performed using a dedicated, commercially available area calculator software. A comparison of the marked colonic area between the abdomen and lung window settings was performed. Results: Overall, the mean marked colonic area was greater in the lung window compared with the abdomen window (8.82 cm2 vs 7.4 cm2, respectively, p < 0.001). Switching the CT window from abdomen to lung increased the identified colonic area in 50 cases (50%). Intraclass correlation showed good agreement between the senior readers and among all readers (0.92 and 0.87, respectively). Similar measurements of the colonic area in both abdomen and lung windows were observed in 26/44 (60%) of the seniors cases and in 7/66 (10%) of the resident cases (p = 0.002). Conclusion: Lung window solely or in combination with abdomen window appears to provide the most accurate colonic identification for preoperative planning of PCNL access and potentially reduce the risk of colonic injury. This pattern is more evident among young urologists, and we propose to introduce it as a standard sequence in PCNL preplanning.

Severe bleeding in patients following "tubeless" percutaneous nephrolithotomy: Predictors of angioembolization

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is a widely used procedure for treating renal calculi. Advanced techniques have improved outcomes, but hemorrhage remains a significant complication. While most cases of hemorrhagic complications are typically managed conservatively, few cases necessitate interventions like angioembolization (AE). The purpose of this study is to identify risk factors closely associated with severe bleeding post-PCNL requiring AE and to assess if these factors can independently predict the type of lesion [arteriovenous fistula (AVF) vs pseudoaneurysm (PA)].

MATERIALS AND METHOD

A retrospective analysis was conducted on 119 patients who underwent "tubeless" PCNL and experienced severe bleeding between January 2018 and December 2023. The study reviewed demographic characteristics, stone characteristics, perioperative factors, and adverse events. The chi-square test and Fisher's exact test were used for univariate analysis. Logistic regression analysis was used in binomial analysis with a value of p < 0.05 considered statistically significant.

RESULTS

Out of 119 patients, 51 required AE. Elevated preoperative serum creatinine levels (>1.5 mg/dl) [p = 0.01], upper pole access [p = 0.008], and a larger access sheath size (standard PCNL vs mini-PCNL) [p ⩽ 0.001] were found to be significantly associated with AE. Logistic regression analysis revealed standard PCNL was significantly associated with post-PCNL bleeding requiring AE (odds ratio [OR]: 50, 95% confidence interval [CI]: 6.529-382.90, p ⩽ 0.001). Stone size and co-morbidities showed no significant association with AE. The average duration of presentation of symptoms post PCNL was 13.6 days. Most patients underwent coiling for AE, with a clinical success rate of 94%.

CONCLUSION

Elevated serum creatinine levels, upper pole access, and tract size >24 Fr are more prone to post-tubeless PCNL severe bleeding, which requires renal AE. The findings suggest that early angiography and possible AE should be considered for at-risk patients. In the future, these predictors may be integrated into predictive models to improve patient risk stratification.

Exploring the competency of the comprehensive complication index over the clavien-dindo classification in standard percutaneous nephrolithotomy: a call for better complication reporting

PURPOSE

The Comprehensive Complication Index (CCI) was introduced in 2013 to overcome the limitations of the Clavien-Dindo Classification (CDC) in grading postoperative complications. The objective of this study to assess the predictive value of the CDC and the CCI for postoperative course in patients undergoing standard adult percutaneous nephrolithotomy (PCNL).

METHODS

A retrospective analysis of 320 renal units that underwent standard PCNL between July 2021 - April 2023 was conducted. The CDC and CCI systems assessed complications occurring within the first 30 days after surgery. A second CCI score was calculated only on the highest CDC grade, and this score was referred to as the noncumulative CCI. A comparative analysis was conducted to determine the predictive efficacy of both evaluation methods regarding the postoperative course.

RESULTS

The postoperative complication rate was 23.1% (74/320). Eight patients (2.5%) experienced multiple complications, resulting in a higher total CCI score than the noncumulative CCI (p = 0.010). Correlation analysis revealed that the CCI correlated with the length of hospital stay (LOS) more precisely than the noncumulative CCI (CCI: r = 0.335; p = 0.004 vs. noncumulative CCI: r = 0.325; p = 0.005). Compared with patients with a single complication, those with multiple complications had similar demographics, preoperative stone characteristics, and intraoperative features.

CONCLUSION

Cumulative CCI proves to be a more effective predictor of LOS and complication burden in standard PCNL than CDC. Hence, using CCI to evaluate complications after PCNL may be a more appropriate approach.

Perioperative Complications in Percutaneous Nephrolithotomy: Predictive Risk Factors and Hemodynamic Alterations

Background Percutaneous nephrolithotomy (PCNL) is one of the most frequently used methods of treating large and/or complex kidney stones. Despite the growing interest in this area, there are relatively few papers that report studies of the changes in hemodynamics in the perioperative period and the potential factors that might influence the patient's condition. This aspect, however, has not been well described in the current literature, although fluctuations in blood pressure, temperature, and electrolyte balance during surgery may also lead to development of complications. Objectives In this study, variations in vital signs during surgery and between surgeries of 134 patients who underwent PCNL were analyzed in relation to other predisposing factors such as hypothermia and the need for blood transfusion. Methods Biochemical data such as systolic blood pressure (SBP) and diastolic blood pressure (DBP), temperature, hemoglobin (Hb), hematocrit (Hct), and serum sodium and potassium were assessed at admission, during PCNL, and at 24 hours after surgery in 134 patients. In this study logistic regression was used to assess the influence of factors such as age, BMI (body mass index), surgery duration, volume of irrigation fluid, number of tracts, estimated blood loss, hypothermia, and requirement of red blood cell transfusions. Results The mean arterial pressure declined during surgery as compared to the preoperative value, reaching a value of 97.34 during the operation. The monitored mean temperature of the patient during the perioperative period was therefore reduced, with a small increase towards the end of the surgery. In the plasma concentrations, there was a decrease compared to pre- and postoperative values, and there was also a decline in 48-hour Hb, Hct, and sodium values. The analysis identified the volume of irrigation fluid as a predictor of mild hypothermia risk. A longer surgery time along with more tracts and worse condition of the patient meant that the patient needed more blood transfusion. It was also noted that none of them influenced the amount of Hb that was lost. Conclusion Variability in the recorded ABCs (airway, breathing, and circulation) before and after PCNL procedures was normative. Despite hypothermia being associated with the volume of irrigation fluids used in surgeries, most of the transfusions were administered in patient-complicated operations and critical states. This suggested that there was potential in defining the modifiable factors that worsen clinically reported outcomes to assist in enhancing protocol.

A Validation of the Swedish Colorectal Cancer Register - With Focus on Histopathology, Complications and Recurrences

Background

There is an urgent need to evaluate the quality of healthcare systems to improve and deliver high-quality care. Clinical registries have become important platforms for performance measurements, improvements, and clinical research. Hence, the quality of data in registries is crucial. This study aimed to assess the validity of data in the Swedish Colorectal Cancer Register (SCRCR).

Methods

Seven hundred patients from 12 hospitals were randomly selected and proportionally distributed among three different hospital categories in Sweden using two-stage cluster sampling. Validity was assessed by re-abstracting data from the medical files of patients reported to the SCRCR in 2015. Data on histopathology, postoperative complications, and a 3-year follow-up were selected for validation. Re-abstracted data were defined as source data, and validity was defined as the proportion of cases in the SRCRC dataset that agreed with the source data. Validity was expressed as the percentage of exact agreement of non-missing data in both data sets, and Cohen´s kappa coefficient (κ) was used to measure the strength of the agreement.

Results

The median agreement of the categorical histopathology variables was 93.4% (κ = 0.83). The general postoperative complication variable showed substantial agreement (84.3%, κ = 0.61). Likewise, the variable for overall cancer recurrence showed an almost perfect agreement (95.7%, κ = 0.86), whereas specific variables for local recurrence and distant recurrence displayed only moderate and fair agreement (85.9% and 89.1%, κ = 0.58 and 0.34, respectively).

Conclusion

Validation of the SCRCR data showed high validity of pathology data and recurrence rates, whereas detailed data on recurrence were not as good. Data on postoperative complications were less reliable, although the incidence and Clavien-Dindo grading of severe complications (grade 3b or higher) were reliable.

Management of urinary stones: state of the art and future perspectives by experts in stone disease

AIM

To present state of the art on the management of urinary stones from a panel of globally recognized urolithiasis experts who met during the Experts in Stone Disease Congress in Valencia in January 2024. Options of treatment: The surgical treatment modalities of renal and ureteral stones are well defined by the guidelines of international societies, although for some index cases more alternative options are possible. For 1.5 cm renal stones, both m-PCNL and RIRS have proven to be valid treatment alternatives with comparable stone-free rates. The m-PCNL has proven to be more cost effective and requires a shorter operative time, while the RIRS has demonstrated lower morbidity in terms of blood loss and shorter recovery times. SWL has proven to be less effective at least for lower calyceal stones but has the highest safety profile. For a 6mm obstructing stone of the pelviureteric junction (PUJ) stone, SWL should be the first choice for a stone less than 1 cm, due to less invasiveness and lower risk of complications although it has a lower stone free-rate. RIRS has advantages in certain conditions such as anticoagulant treatment, obesity, or body deformity. Technical issues of the surgical procedures for stone removal: In patients receiving antithrombotic therapy, SWL, PCN and open surgery are at elevated risk of hemorrhage or perinephric hematoma. URS, is associated with less morbidity in these cases. An individualized combined evaluation of risks of bleeding and thromboembolism should determine the perioperative thromboprophylactic strategy. Pre-interventional urine culture and antibiotic therapy are mandatory although UTI treatment is becoming more challenging due to increasing resistance to routinely applied antibiotics. The use of an intrarenal urine culture and stone culture is recommended to adapt antibiotic therapy in case of postoperative infectious complications. Measurements of temperature and pressure during RIRS are vital for ensuring patient safety and optimizing surgical outcomes although techniques of measurements and methods for data analysis are still to be refined. Ureteral stents were improved by the development of new biomaterials, new coatings, and new stent designs. Topics of current research are the development of drug eluting and bioresorbable stents. Complications of endoscopic treatment: PCNL is considered the most invasive surgical option. Fever and sepsis were observed in 11 and 0.5% and need for transfusion and embolization for bleeding in 7 and 0.4%. Major complications, as colonic, splenic, liver, gall bladder and bowel injuries are quite rare but are associated with significant morbidity. Ureteroscopy causes less complications, although some of them can be severe. They depend on high pressure in the urinary tract (sepsis or renal bleeding) or application of excessive force to the urinary tract (ureteral avulsion or stricture). Diagnostic work up:  Genetic testing consents the diagnosis of monogenetic conditions causing stones. It should be carried out in children and in selected adults. In adults, monogenetic diseases can be diagnosed by systematic genetic testing in no more than 4%, when cystinuria, APRT deficiency, and xanthinuria are excluded. A reliable stone analysis by infrared spectroscopy or X-ray diffraction is mandatory and should be associated to examination of the stone under a stereomicroscope. The analysis of digital images of stones by deep convolutional neural networks in dry laboratory or during endoscopic examination could allow the classification of stones based on their color and texture. Scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) is another fundamental research tool for the study of kidney stones. The combination of metagenomic analysis using Next Generation Sequencing (NGS) techniques and the enhanced quantitative urine culture (EQUC) protocol can be used to evaluate the urobiome of renal stone formers. Twenty-four hour urine analysis has a place during patient evaluation together with repeated measurements of urinary pH with a digital pH meter. Urinary supersaturation is the most comprehensive physicochemical risk factor employed in urolithiasis research. Urinary macromolecules can act as both promoters or inhibitors of stone formation depending on the chemical composition of urine in which they are operating. At the moment, there are no clinical applications of macromolecules in stone management or prophylaxis. Patients should be evaluated for the association with systemic pathologies.

PROPHYLAXIS

Personalized medicine and public health interventions are complementary to prevent stone recurrence. Personalized medicine addresses a small part of stone patients with a high risk of recurrence and systemic complications requiring specific dietary and pharmacological treatment to prevent stone recurrence and complications of associated systemic diseases. The more numerous subjects who form one or a few stones during their entire lifespan should be treated by modifications of diet and lifestyle. Primary prevention by public health interventions is advisable to reduce prevalence of stones in the general population. Renal stone formers at "high-risk" for recurrence need early diagnosis to start specific treatment. Stone analysis allows the identification of most "high-risk" patients forming non-calcium stones: infection stones (struvite), uric acid and urates, cystine and other rare stones (dihydroxyadenine, xanthine). Patients at "high-risk" forming calcium stones require a more difficult diagnosis by clinical and laboratory evaluation. Particularly, patients with cystinuria and primary hyperoxaluria should be actively searched.

FUTURE RESEARCH

Application of Artificial Intelligence are promising for automated identification of ureteral stones on CT imaging, prediction of stone composition and 24-hour urinary risk factors by demographics and clinical parameters, assessment of stone composition by evaluation of endoscopic images and prediction of outcomes of stone treatments. The synergy between urologists, nephrologists, and scientists in basic kidney stone research will enhance the depth and breadth of investigations, leading to a more comprehensive understanding of kidney stone formation.

Effect of access sheath diameter used in percutaneous nephrolithotomy on renal function: a prospective randomized study

We aimed to determine the effect of the access sheath diameter used in percutaneous nephrolithotomy (PNL) on renal function. We also investigated the predictors of impaired renal function. Data were prospectively collected from patients who underwent PNL from December 2020 to December 2021. The patients were randomized into two groups according to access sheath diameter: Group 1 (22 Fr, n = 44) and Group 2 (28 Fr, n = 44). Relative renal function (RRF) was calculated by technetium-99 m dimercaptosuccinic acid scintigraphy, and glomerular filtration rate (GFR) was calculated by diethylenetriamine pentaacetic acid scintigraphy. A difference of 5% or more in RRF was considered a significant functional change. Preoperative and postoperative Kidney Injury Molecule-1 (KIM-1) levels were measured. Preoperative demographic data and stone characteristics were similar between the groups. There were also no statistically significant differences between the groups in terms of scar development, changes in RRF, GFR, or KIM-1/creatinine (Cr) (p > 0.05). Significant deterioration in RRF was detected in a total of six (6.8%) patients, three in each group. The factors predicting loss of function were analyzed by regrouping the patients without loss of function as Group A (n = 82) and those with loss as Group B (n = 6). Only stone volume was statistically significant in multivariate analysis (p = 0.002). Access sheath diameter had no significant effect on renal function after PNL. However, the stone volume was found to independently correlate to a loss of renal function after PNL.

Ureteroscopic lithotripsy with pressure-measuring ureteral access sheath for large ureteral stones

INTRODUCTION

To evaluate the safety and efficacy of ureteroscopic lithotripsy with pressure-measuring ureteral access sheath (PM-UAS) for large ureteral stones.

MATERIAL AND METHODS

A total of 258 consecutive patients with large ureteral stones ≥15 mm was enrolled. They were treated by ureteroscopic lithotripsy with PM-UAS in the oblique supine lithotomy position. The technology can precisely monitor and automatically control cavity pressure. The cavity pressure control value was set at -15 mmHg∼-5 mmHg. The cavity pressure limit value was set at 30 mmHg. Infusion flow rate was set at 100-200 ml/min. Postoperative data such as stone-free rate and complications were analyzed.

RESULTS

PM-UAS was successfully implanted in 225 patients at one stage. Eighteen cases of patients who had failed the first surgery were successfully treated with a second operation. Fifty-one cases with stones migrating up to the kidney were converted to flexible lithotripsy. The other 15 cases were converted to percutaneous nephrolithotomy due to significant ureteral stenosis. The operative time was 49.5 ± 11.2 min. The stone-free rates after one month and three months were 87.2% (212/243) and 94.2% (229/243), respectively. Complications from grade I to II were observed in 25(10.3%) patients. No other complications from grade III to V were noted.

CONCLUSION

The ureteroscopic lithotripsy with PM-UAS is safe and efficacious for large ureteral stones.

Factors associated to hemoglobin decrease after percutaneous nephrolithotomy: a retrospective study

OBJECTIVE

This study aims to determine the preoperative and perioperative risk parameters associated with a decrease in hemoglobin (Hb) in patients undergoing percutaneous nephrolithotomy (PCNL).

METHODS

We collected prospective data of consecutive patients who underwent PCNL from January 2018 to December 2022. The median decrease in post-operative hemoglobin levels compared to pre-operative was found to be 1.5 g/dl. This value was the cut-off value that divided the sample into two groups. Group 1 has a decrease in Hb levels that is higher or equal to the cutoff, group 2 has a decrease in Hb levels that is lower than the cut-off. All preoperative, stone characteristics and perioperative factors were recorded.

RESULTS

A total of 273 patients were included in the study, 141 in Group 1 and 132 in Group 2. The mean age of Group 1 was significantly higher (55.48 ± 8.73 vs 45.9 ± 10.75 years, p < 0.05). The mean bleeding of Group 1 was significantly higher (285.85 ± 113.68 vs 135 ± 77.54 ml, p < 0.05). There was a significant difference in mean operation time between groups (86.35 ± 32.05 vs 64.89 ± 27.83 min, p < 0.05). Multivariate analysis showed that the variables age, comorbid diabetes mellitus, intraoperative bleeding amount, and operation time had a significant relationship with Hb reduction in patients undergoing PCNL (p < 0.05).

CONCLUSIONS

Older age, comorbid diabetes mellitus, large amounts of intraoperative bleeding, and longer operating time are factors associated with PCNL-related postoperative hemoglobin decrease.

Assessment of Effectiveness and Safety of Aspiration-Assisted Nephrostomic Access Sheaths in PCNL and Intrarenal Pressures Evaluation: A Systematic Review of the Literature

Background: Different suction-assisted nephrostomic sheaths have been developed for percutaneous nephrolithotomy (PCNL). Objectives: (1) To examine PCNL techniques performed with different aspiration-assisted sheaths (Clear Petra® sheath, Superperc, SuperminiPCNL, and a miniPCNL patented sheath), with specific regard to effectiveness and safety outcomes in adult and paediatric patients; (2) to extrapolate intrarenal pressure (IRP) data during these procedures. Methods: A systematic literature search was performed in accordance with PRISMA guidelines. Relevant articles up to 8 February 2024 were included. Results: Twenty-five studies were selected, thirteen retrospective and twelve prospective. The use of four different aspirating sheaths for miniPCNL was reported: Clear Petra® sheath, Superperc, SuperminiPCNL, and a miniPCNL patented sheath. Stone free rates (SFRs) across techniques ranged from 71.3% to 100%, and complication rates from 1.5% to 38.9%. Infectious complication rates varied from 0 to 27.8% and bleeding complication rates from 0 to 8.9%. Most complications were low grade ones. The trend among studies comparing aspiration- and non-aspiration-assisted miniPCNL was towards equivalent or better SFRs and lower overall infectious and bleeding complication rates in suction techniques. Operation time was consistently lower in suction procedures, with a mean shortening of the procedural time of 19 min. Seven studies reported IRP values during suction miniPCNL. Two studies reported satisfactory SFRs and adequate safety profiles in paediatric patient cohorts. Conclusions: MiniPCNL with aspirating sheaths appears to be safe and effective in both adult and paediatric patients. A trend towards a reduction of overall infectious and bleeding complications with respect to non-suction procedures is evident, with comparable or better SFRs and consistently shorter operative times. The IRP profile seems to be safe with the aid of aspirating sheaths. However, high quality evidence on this topic is still lacking.

Propensity Score-Matched Analysis of Perioperative Outcomes of Supine versus Prone Percutaneous Nephrolithotomy

Objective: To compare the perioperative outcomes of supine and prone percutaneous nephrolithotomy (PCNL). Methods: A retrospective search of a tertiary medical center database yielded 517 patients who underwent supine (n = 91) or prone (n = 426) PCNL between September 2015 and July 2020. Data on demographics, baseline clinical parameters, and stone burden were included as predictors in a logistic regression model, generating a set of propensity scores. Seventy patients after supine PCNL were propensity score-matched 1:1 with patients after prone PCNL and compared for operative time, perioperative complications, system complexity, and stone-free rate. Results: We found that the operative time was significantly shorter in the supine PCNL group than in the prone PCNL group (85.5 ± 25.2 min vs. 96.4 ± 25.8 min, respectively; p = 0.012). The majority of both groups had low-grade (I-II) complexity systems (85.6% and 88.6%, respectively), with no significant difference among all grade groups (p = 0.749). There were no significant differences between the supine and prone PCNL groups in terms of the overall perioperative complication rate (8.6% vs. 4.3%, respectively; p = 0.301) or stone-free rate (74.3 vs. 65.7%, respectively; p = 0.356), while the rate of blood transfusion was significantly higher in the supine group (p = 0.023). Conclusions: In our study, we used propensity score matching to compare patients who underwent PCNL in the supine or prone position, adjusting for selection bias. Supine PCNL was associated with a shorter operative time but a higher blood transfusion rate, with no differences in the overall complication and stone-free rates.

Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study

PURPOSE

To evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones.

METHODS

We analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient's demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization.

RESULTS

Overall, median (IQR) age and stone volume were 56 (47-65) years and 1.7 (0.8-4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time.

CONCLUSION

One out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Learning curve of ultrasound-guided percutaneous nephrolithotripsy in the treatment of complex renal calculi

OBJECTIVE

This study was performed to investigate the learning curve of ultrasound-guided percutaneous nephrolithotripsy (PCNL) for the treatment of complex renal calculi.

METHODS

Seventy-two patients with complex renal stones who underwent ultrasound-guided PCNL by the same operator from November 2016 to September 2020 were retrospectively analyzed. The learning curve of PCNL for complex renal stones was analyzed using multifactorial cumulative sum (CUSUM) analysis and best-fit curves.

RESULTS

The CUSUM best-fit curve peaked at Case 36, which represented the minimum number of cumulative cases required to cross the learning curve for this surgical procedure. Accordingly, the learning curve was divided into a learning improvement period (36 cases) and a proficiency phase (36 cases). Compared with the learning improvement period, the proficiency phase was characterized by a shorter puncture time and operation time, a smaller drop in the hemoglobin level, and a lower postoperative complication rate.

CONCLUSION

The learning curve of PCNL for the treatment of complex renal calculi can be divided into a learning improvement period and a proficiency phase, and the minimum cumulative number of cases is 36.

Tranexamic acid for percutaneous nephrolithotomy: an abridged Cochrane review

OBJECTIVE

To assess the effects of tranexamic acid (TXA) in individuals with kidney stones undergoing percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

We performed a literature search of Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, grey literature, and conference proceedings. We included randomised controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients aged ≥18 years. Two review authors independently classified studies and abstracted data. Primary outcomes were blood transfusion, stone-free rate (SFR), thromboembolic events (TEE). We rated the certainty of evidence (CoE) according to the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach using a minimally contextualised approach with pre-defined thresholds for minimally clinically important differences (MCID).

RESULTS

We included 10 RCTs assessing the effect of systemic TXA in PCNL vs placebo (or no TXA). Eight studies were published as full text. Based on an adjusted baseline risk of blood transfusion of 5.7%, systemic TXA may reduce blood transfusions (risk ratio [RR] 0.45, 95% confidence interval [CI] 0.27-0.76). Based on an adjusted baseline SFR of 75.7%, systemic TXA may increase SFR (RR 1.11, 95% CI 0.98-1.27). There is probably no difference in TEEs (risk difference 0.001, 95% CI -0.01 to 0.01). Systemic TXA may increase adverse events (AEs) (RR 5.22, 95% CI 0.52-52.72). Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84-1.57). The CoE for most outcomes was assessed as low or very low.

CONCLUSIONS

Based on a body of evidence of 10 RCTs, we found that systemic TXA in PCNL may reduce blood transfusions, major surgical complications, and hospital length of stay, as well as improve the SFR; however, it may increase AEs. These findings should inform urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Vacuum-assisted access sheath in supine mini-percutaneous nephrolithotomy (mini-PCNL)

INTRODUCTION

The vacuum-assisted access sheath is a new device for the treatment of kidney stones with percutaneous nephrolithotomy (PCNL).

OBJECTIVE

Our aim was to compare the stone-free rate (SFR) and complications between standard mini percutaneous nephrolithotomy (Mini-PCNL) and vacuum-assisted PCNL (Va-PCNL).

METHODS

Retrospective study of patients undergoing Mini-PCNL and Va-PCNL from January 2018 to June 2022. Va-PCNL was performed with a disposable sheath (ClearPetra®) with continuous high-flow irrigation and vacuum fluid dynamics for easier stone fragment removal. Baseline patient characteristics, surgical outcomes, perioperative and postoperative data were collected. We compared SFR and complications.

RESULTS

A total of 136 patients were identified, 57 (41,9%) underwent Va-PCNL and 79 (58,15%) Mini-PCNL. Mean operative time was significantly shorter in the Va-PCNL group (95 min.) than in Mini-PCNL (146 min; P = ,001) group. The tubeless technique was performed more frequently in Va-PCNL group (61,4% vs. 34,2%; P = ,002). We did not observe any differences in postoperative complications. The mean hospital stay was significantly lower in Va-PCNL with 1,7 ± 1,9 days per patient compared with 2,7 ± 1,5 days in the Mini-PCNL group (P = ,001). There were no differences in SFR at 3 months between Va-PCNL (71,9%) and Mini-PCNL (71,8%; P =v ,848).

CONCLUSION

Patients treated with Va-PCNL had comparable results to Mini-PCNL, showing equal SFR with similar infectious complications rates. Potential benefits of Va-PCNL include shorter operative time and postoperative stay.

Efficacy of simultaneous bilateral surgery using the oblique overriding position in the treatment of bilateral kidney stones

To compare the safety and the efficacy of simultaneous bilateral surgery in the oblique overriding position versus staging surgery in the treatment of bilateral renal calculi. A total of 46 patients with bilateral renal stones from May 2019 to January 2022 in our center were retrospectively analyzed, including 29 males and 17 females, with a mean age of 48 ± 13.6 years, body mass index of 24.6 ± 2.3 kg/m2, and uneven size of bilateral renal stones, with a mean diameter of 29.5 ± 9.1 mm on the side with the larger kidney stones (PCNL) and a mean diameter of 13.1 ± 3.2 mm on the side with the smaller kidney stones. The patients were divided into two groups for simultaneous and stepwise bilateral endoscopic surgery, and the operative time, anesthesia time, postoperative hemoglobin, blood creatinine, postoperative VAS pain score, Clavien complication rating, average hospital stay, and stone removal rate at one month after surgery were evaluated in both groups. The simultaneous group outperformed the other group in anesthesia time, operative time, VAS score, and mean number of days in the hospital, and there were no significant differences between the two groups in postoperative hemoglobin drop values, hematocrit elevation values, Clavien complication ratings, and stone clearance rate at one month. Both simultaneous surgery and staging surgery were safe and effective. Simultaneous surgery can effectively shorten the operation and anesthesia time, and reduce the postoperative pain and hospital days of patients while ensuring similar stone clearance rates.

Tranexamic acid for percutaneous nephrolithotomy

BACKGROUND

Percutaneous nephrolithotomy (PCNL) is the gold standard for the treatment of large kidney stones but comes with an increased risk of bleeding compared to other treatments, such as ureteroscopy and shock wave lithotripsy. Tranexamic acid (TXA) is an antifibrinolytic agent that has been used to reduce bleeding complications in other settings.

OBJECTIVES

To assess the effects of TXA in individuals with kidney stones undergoing PCNL.

SEARCH METHODS

We performed a comprehensive literature search of the Cochrane Library, PubMed (including MEDLINE), Embase, Scopus, Global Index Medicus, trials registries, other sources of the grey literature, and conference proceedings. We applied no restrictions on the language of publication nor publication status. The latest search date was 11 May 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared treatment with PCNL with administration of TXA to placebo (or no TXA) for patients ≥ 18 years old.

DATA COLLECTION AND ANALYSIS

Two review authors independently classified studies and abstracted data. Primary outcomes were: blood transfusion, stone-free rate (SFR), and thromboembolic events (TEEs). Secondary outcomes were: adverse events (AEs), secondary interventions, major surgical complications, minor surgical complications, unplanned hospitalizations or readmissions, and hospital length of stay (LOS). We performed statistical analyzes using a random-effects model. We rated the certainty of evidence (CoE) according to the GRADE approach using a minimally contextualized approach with predefined thresholds for minimally clinically important differences (MCIDs).

MAIN RESULTS

We analyzed 10 RCTs assessing the effect of systemic TXA in PCNL versus placebo (or no TXA) with 1883 randomized participants. Eight studies were published as full text. One was published in abstract proceedings, but it was separated into two separate studies for the purpose of our analyzes. Average stone surface area ranged 3.45 to 6.62 cm2. We also found a single RCT published in full text assessing the effects of topical TXA in PCNL versus placebo (or no TXA) with 400 randomized participants, the results of which are further described in the review. Here we focus only on the results of TXA used systemically. Blood transfusion - Based on a representative baseline risk of 5.7% for blood transfusions taken from a large presentative observational studies, systemic TXA may reduce blood transfusions (risk ratio (RR) 0.45, 95% confidence interval (CI) 0.27 to 0.76; I2 = 28%; 9 studies, 1353 participants; low CoE). We assumed an MCID of ≥ 2%. Based on 57 participants per 1000 with placebo (or no TXA) being transfused, this corresponds to 31 fewer (from 42 fewer to 14 fewer) participants being transfused per 1000. Stone-free rate - Based on a representative baseline risk of 75.7% for SFR, systemic TXA may increase SFRs (RR 1.11, 95% CI 0.98 to 1.27; I2 = 62%; 4 studies, 603 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 757 participants per 1000 being stone free with placebo (or no TXA), this corresponds to 83 more (from 15 fewer to 204 more) stone-free participants per 1000. Thromboembolic events - There is probably no difference in TEEs (risk difference (RD) 0.00, 95% CI -0.01 to 0.01; I2 = 0%; 6 studies, 841 participants; moderate CoE). We assumed an MCID of ≥ 2%. Since there were no thromboembolic events in intervention and/or control groups in 5 out of6 studies, we opted to assess a risk difference with systemic TXA for this outcome. Adverse events - Systemic TXA may increase AEs (RR 5.22, 95% CI 0.52 to 52.72; I2 = 75%; 4 studies, 602 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 23 participants per 1000 with placebo (or no TXA) having an adverse event, this corresponds to 98 more (from 11 fewer to 1000 more) participants with adverse events per 1000. Secondary interventions - Systemic TXA may have little to no effect on secondary interventions (RR 1.15, 95% CI 0.84 to 1.57; I2 = 0%; 2 studies, 319 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 278 participants per 1000 with placebo (or no TXA) having a secondary intervention, this corresponds to 42 more (from 44 fewer to 158 more) participants with secondary interventions per 1000. Major surgical complications - Based on a representative baseline risk for major surgical complications of 4.1%, systemic TXA may reduce major surgical complications (RR 0.36, 95% CI 0.21 to 0.62; I2 = 0%; 5 studies, 733 participants; moderate CoE). We assumed an MCID of ≥ 2%. Based on 41 participants per 1000 with placebo (or no TXA) having a major surgical complication, this corresponds to 26 fewer (from 32 fewer to 16 fewer) participants with major surgical complications per 1000. Minor surgical complications - Systemic TXA may reduce minor surgical complications (RR 0.71, 95% CI 0.45 to 1.10; I2 = 76%; 5 studies, 733 participants; low CoE). We assumed an MCID of ≥ 5%. Based on 396 participants per 1000 with placebo (or no TXA) having a minor surgical complication, this corresponds to 115 fewer (from 218 fewer to 40 more) participants with minor surgical complications per 1000. Unplanned hospitalizations or readmissions - We are very uncertain how unplanned hospitalizations or readmissions are affected (RR 1.55, 95% CI 0.45 to 5.31; I2 = not applicable; 1 study, 189 participants; very low CoE). We assumed an MCID of ≥ 2%. Hospital length of stay - Systemic TXA may reduce hospital LOS (mean difference 0.52 days lower, 95% CI 0.93 lower to 0.11 lower; I2 = 98%; 7 studies, 1151 participants; low CoE). We assumed an MCID of ≥ 0.5 days.

AUTHORS' CONCLUSIONS

Based on 10 RCTs with substantial methodological limitations that lowered all CoE of effect, we found that systemic TXA in PCNL may reduce blood transfusions, major and minor surgical complications, and hospital LOS, as well as improve SFRs; however, it may increase AEs. We are uncertain about the effects of systemic TXA on other outcomes. Findings of this review should assist urologists and their patients in making informed decisions about the use of TXA in the setting of PCNL.

Outcome of Mini-PCNL Under Loco-Regional Anesthesia: Outcomes of a Systematic Review

PURPOSE OF REVIEW

Miniaturized PCNL (mi-PCNL) for stone disease is performed under a general anesthesia. However, the role of loco-regional anesthesia in mi-PCNL and its outcomes are not well defined yet. Here, we review the outcomes and complications of loco-regional anesthesia for mi-PCNL. A Cochrane-style review was performed in accordance with the preferred reporting items for systematic reviews to evaluate the outcomes of loco-reginal anesthesia for URS in stone disease, including all English language articles from January 1980 and October 2021.

RECENT FINDINGS

Ten studies with a total of 1663 patients underwent mi-PCNL under loco-regional anesthesia. The stone-free rate (SFR) for mi-PCNL under neuro-axial anesthesia ranged between 88.3 and 93.6%, while it ranged between 85.7 and 93.3% for mi-PCNL under local anesthesia (LA). The conversion rate to another anesthesia modality was 0.5%. The complications ranged widely between 3.3 and 85.7%. The majority were Grade I-II complications and none of the patients had grade V complications. Our review shows that mi-PCNL under loco-regional anesthesia is feasible with good SFR and a low risk of major complications. The conversion to general anesthesia is needed in a small minority, with the procedure itself being well tolerated and a big step towards establishing an ambulatory pathway for these patients.

Comparative analysis of re-entry malecot and nelaton catheters after standard percutaneous nephrolithotomy in adult patients: a cross-sectional study

Drainage catheters are used almost routinely to provide urinary drainage, prevent extravasation of urine, and create tamponade against bleeding after percutaneous nephrolithotomy (PNL). In the literature, there is no standardized approach to determining which type of catheter is superior. In this context, we aimed to comparatively analyze two different types of catheters (re-entry malecot catheter and nelaton catheter) in terms of success and complications, which we use for drainage after a PNL operation and which have very different costs. Patients who underwent PNL for kidney stones between January 2018 and October 2022 were included in the study. The data of a total of 148 patients who had a 16-F reentry malecot nephrostomy catheter or a 16-F nelaton catheter were analyzed. In addition to the demographic characteristics of the patients, stone characteristics, operative data, hospitalization time, analgesia requirement, hemoglobin exchange, amount of blood transfusion, and postoperative data (success and complications) were comparatively evaluated. The current unit price for a reentry malecot and a nelaton catheter is 4.7 United States dollars (USD) and 0.11 USD, respectively. There were a total of 148 patients in the study, 63 of whom were nelaton catheters and 85 were reentry malecots, and the mean age was 39.95 ± 13.28 years. There was no statistically significant difference between preoperative stone sizes and residual stone rates according to the groups. In addition, there was no statistically significant difference between the groups in terms of access site and stone localization. There was no significant difference between the groups in terms of complication rates according to the Clavien-Dindo classification, Hb levels, blood transfusion rates, operation times, or hospitalization times. In conclusion, if a second procedure is planned, a reentry malecot catheter may be preferred. Apart from this situation, nelaton catheters should be preferred because they are similar to reentry catheters in terms of effectiveness, and side effects and are more economical than reentry catheters in terms of cost.

Prediction of surgical decision and postoperative renal function using RENAL nephrometry score for localized renal masses: A prospective study

Purpose

The purpose of the study is to assess the value of RENAL nephrometry score (RNS) in predicting surgical decisions, complications, and decreases in kidney function in patients with localized renal tumors.

Methods

Cases with solitary, solid, and enhancing renal masses were included, scheduled for nephron-sparing surgery (NSS), and assessed using routine laboratory and radiological data necessary for calculating the RENAL score. The primary endpoint was conversion to radical nephrectomy (RN), while the secondary endpoint was the prediction of a drop in renal function assessed by postoperative estimated glomerular filtration rate (eGFR) at the last follow-up visit compared with the preoperative values. The association between the scoring system and perioperative outcomes was evaluated.

Results

In all, 84 cases were included, NSS was accomplished in 67 cases while conversion to RN was mandatory in 17 patients, median (interquartile range) RENAL score was 6.2 (4-10) for NSS and 9.7 (6-12) for RN (P < 0.001). Higher grades of complications were observed in the high-complexity subgroup. eGFR was 79.8 that dropped to 75.6 ml/min/1.73 m2 in the late value in patients who underwent NSS, while it was 82.9 that dropped to 58.3 ml/min/1.73 m2 in the late value in patients who converted into RN (P < 0.001). The percentage of drop in eGFR was significantly higher in the moderate and high-risk groups, which was positively correlated with the warm ischemia time. Regression analysis revealed that the continuous RENAL score was a more significant predictor of conversion to RN than tumor size alone. In the 67 NNS cases, the percentage decrease in eGFR was predicted using the continuous RENAL score.

Conclusion

The RNS is a significant predictor of conversion to RN and can predict the percentage decrease in eGFR after NSS. Further investigations and follow-ups are necessary.

Impact of pelvicalyceal anatomical variation on surgical outcomes of endoscopic combined intrarenal surgery

Objectives

The objective of this work is to investigate the impact of the pelvicalyceal anatomical system (PCS) on calyceal stone formation and surgical outcomes of endoscopic combined intrarenal surgery (ECIRS) for renal and/or proximal ureteral stones with a diameter >15 mm.

Patients and methods

PCS was classified as Type I (single pelvis) or Type II (divided pelvis) according to the simple anatomical Takazawa classification. Using prospectively collected data from January 2016 to April 2020, 219 patients were retrospectively reviewed. After excluding patients who underwent a staged procedure, had hydronephrosis greater than grade 2, prior nephrostomy tubes, and failed to access the renal collecting system, 115 patients (Type I: 81, Type II: 34) were included, and the distribution of calyceal stones and surgical outcomes in ECIRS were compared between Types I and II PCS.

Results

The median number of renal stone calyces in the Type II group was significantly more than that in the Type I group (p = 0.016). In particular, the Type II group possessed more upper stone calyces. Multivariate logistic regression analysis revealed that Type II PCS was associated with an increased odds ratio (OR) for the presence of upper stone calyces (OR: 2.93, p = 0.018). The stone-free (SF) status at 1 month after surgery, confirmed by abdominal plain radiography, was significantly higher in the Type I group compared with that in Type II (67.9% vs. 39.4%, respectively; p = 0.006). The requirement for additional surgical interventions was significantly higher in the Type II group compared with that in Type I (35.4% vs. 7.4%, respectively; p < 0.001). Multivariate analysis revealed that the number of stone calyces (OR: 4.26; p = 0.001) and Type II PCS (OR: 3.43; p = 0.009) were independent predictors of residual stones after ECIRS.

Conclusion

We first revealed that the anatomic properties of PCS play a role in both upper calyceal stone formation and in the success of the ECIRS procedure. Because the SF rate in Type II PCS was significantly lower than that in Type I PCS, additional percutaneous nephrolithotomy tracts might be required, even for ECIRS.

The efficacy and safety of one-stage endoscopy combined with intrarenal surgery (mini-nephrostomy tract) in the prone split-leg position for complex renal calculi

Background

The goal of this study was to determine the safety and efficacy of endoscopic combined intrarenal surgery (ECIRS) performed in the prone split-leg position for the treatment of complex renal stones.

Materials and methods

A mature ECIRS protocol was designed. Retrospective analysis was conducted of medical records between January 2020 and December 2021 of patients with complex renal stones at one center who underwent ECIRS by 2 skilled surgeons using retrograde flexible ureteroscopy and mini-percutaneous nephrolithotomy in the prone split-leg position.

Results

A total of 44 patients were included in this study. Mean stone size was 26.1 ± 12.7 mm, and the number of calyces involved was 4.36 ± 2.09. Mean operative time was 71.1 ± 21.8 minutes. Postoperative decline in hemoglobin was 15.8 ± 9.8 g/L. Seventy-five percent of patients achieved stone-free status. The mean number of residual stones was 2.8 ± 2.3, and the mean residual stone size was 10.30 ± 4.76 mm. Six patients (13.6%) developed postoperative complications, including 4 with fever during the first 2 days postoperatively and 2 patients with transient postoperative pain. No patients developed severe complications.

Conclusions

Endoscopic combined intrarenal surgery in the prone split-leg position can be performed safely by experienced surgeons using retrograde flexible ureteroscopy in conjunction with mini-percutaneous nephrolithotomy as a successful technique for the treatment of complex renal stones.

Stone-scoring systems for predicting complications in percutaneous nephrolithotomy: A systematic review of the literature

Objective

Percutaneous nephrolithotomy is a treatment of choice for larger stones of the upper urinary tract. Currently, several nephrolithometric nomograms for prediction of post-operative surgical outcomes have been proposed, although uncertainties still exist regarding their roles in the estimation of complications.

Methods

We conducted a systematic review on PubMed and Web of Sciences databases including English studies with at least 100 cases and published between January 2010 and December 2021. We identified original articles evaluating correlations between the Guy's stone score, the stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence or stone density (E) (S.T.O.N.E.), Clinical Research Office of the Endourological Society (CROES), and Seoul National University Renal Stone Complexity (S-ReSC) scores and post-operative complications in adult patients. We also included newly designed nomograms for prediction of specific complications.

Results

After an initial search of 549 abstracts, we finally included a total of 18 papers. Of them, 11 investigated traditional nephrolithometric nomograms, while seven newly designed nomograms were used to predict specific complications. Overall, 7316 patients have been involved. In total, 14 out of 18 papers are derived from retrospective single-center studies. Guy's stone score obtained correlation with complications in five, S.T.O.N.E. nephrolithometry score in four, while CROES score and S-ReSC score in three and two, respectively. None of the studies investigated minimally invasive percutaneous nephrolithotomy (PCNL) and all cases have been conducted in prone position. Considering newly designed nomograms, none of them is currently externally validated; five of them predict post-operative infections; the remaining two have been designed for thromboembolic events and urinary leakage.

Conclusion

This review presents all nomograms currently available in the PCNL field and highlights a certain number of concerns. Published data have appeared contradictory; more recent tools for prediction of post-operative complications are frequently based on small retrospective cohorts and lack external validations. Heterogeneity among studies has also been noticed. More rigorous validations are advisable in the future, involving larger prospective patients' series and with the comparison of different tools.

Knowledge-map analysis of percutaneous nephrolithotomy (PNL) for urolithiasis

Percutaneous nephrolithotomy (PNL) has been used in the treatment of urolithiasis for more than 20 years. However, bibliometric analysis of the global use of PNL for urolithiasis is rare. We retrieved the literatures on PNL and urolithiasis from Web of science core collection database. VOSviewer was used to analyze keywords, citations, publications, co-authorship, themes, and trend topics. A total of 3103 articles were analyzed, most of which were original ones. The most common keywords were "percutaneous nephrology" and "urolithiasis", both of which were closely related to "ureteroscopy". Journal of Urology and Zeng Guohua from the First Affiliated Hospital of Guangzhou Medical University were the most published journal and author in this field. The most productive country was the United States, and its closest partners were Canada, China, and Italy. The five hot topics were the specific application methods and means, risk factors of urolithiasis, the development of treatment technology of urolithiasis, the characteristics, composition, and properties of stones, and the evaluation of curative effect. This study aimed to provide a new perspective for PNL treatment of urolithiasis and provided valuable information for urologic researchers to understand their research hotspots, cooperative institutions, and research frontiers.

The clinical role of bacteremia and bacterial spread into the irrigation fluid during percutaneous nephrolithotomy: a prospective study

PURPOSE

Backflow of pathogens and endotoxins from the renal pelvis to the bloodstream is one supposed mechanism for infectious complications development after endourological stones surgery. The aim of this study is detecting to prove bacterial spread into irrigation fluid and bloodstream during percutaneous nephrolithotomy (PCNL) and to correlate these findings with clinical and microbiological parameters and infectious complications (IC).

METHODS

Bladder urine culture (BUC) was retrieved before PCNL; during the procedure, 2 blood samples (BC) and an irrigation fluid sample during fragmentation (SFUC) were collected for culture. Stone culture (SC) was also obtained. Patients were evaluated post-operatively for IC.

RESULTS

Sixty-one patients were prospectively included. IC occurred in 15 patients (24.6%). SFUC was positive in 7/61 (11.5%); BC in 10/61 (16.4%). Among patients with positive BC; BUC, SFUC and SC were positive in 9 (90%), 6 (60%), and 8 (80%) cases, respectively. Out of 10 patients with positive BC, 4 developed post-operative IC. Pre-operative renal impairment (p = 0.04), intraoperative-evaluated stone residual (p = 0.02), BUC (p = 0.004), and SC (p = 0.008) were associated with IC. No correlation was found between bacterial spread in the irrigation fluid and blood and IC.

CONCLUSION

We proved that bacteria can be detected into the irrigation fluid and blood during PCNL. This transient bacteremia appears to be unrelated to IC development.

Factors associated with complications after percutaneous nephrolithotomy: an analysis of 1,066 cases

OBJECTIVE

The aim of this study was to identify predictive factors for complications after percutaneous nephrolithotomy.

METHODS

We prospectively analyzed patients who underwent percutaneous nephrolithotomy from June 2011 to October 2018. The association of preoperative and intraoperative factors with the presence of complications was assessed using univariate and multivariate analyses. The significance level was set at p<0.05.

RESULTS

A total of 1,066 surgeries were evaluated, and the overall complication rate was 14.9%. In all, 105 (9.8%) surgeries were performed in the prone position, and 961 (90.2%) were performed in the supine position. Univariate analysis demonstrated that surgical position, upper pole puncture, surgical time, number of tracts, and Guys Stone Score were associated with complications. In multivariate analyses, prone position (odds ratio [OR] 2.10; p=0.003), surgical time ≥90 min (OR 1.76; p=0.014), upper pole puncture (OR 2.48; p<0.001), and Guys Stone Score 3 or 4 (OR 1.90; p=0.033) were independent predictive factors for complications after percutaneous nephrolithotomy.

CONCLUSION

Performing percutaneous nephrolithotomy in the supine position, in under 90 min, and avoiding upper pole punctures may reduce complications during the treatment of large kidney stones.

Reliability of nephrolithometric nomograms in patients treated with minimally invasive percutaneous nephrolithotomy: A precision study

Objectives

The study aimed to evaluate quality of nephrolithometric nomograms to predict stone-free rates (SFRs) and complication rates (CRs) in case of minimally invasive percutaneous nephrolithotomy (PNL). In the last decade, nomograms have been introduced to estimate the SFRs and CRs of PNL. However, no data are available regarding their reliability in case of utilization of miniaturized devices. Herein we present a prospective multicentric study to evaluate reliability of Guy's stone score (GSS), the stone size, tract length, obstruction, number of involved calyces, and essence of stone (S.T.O.N.E.) nephrolithometry score and Clinical Research Office of the Endourological Society (CROES) score in patients treated with minimally invasive PNL.

Methods

We evaluated SFRs and CRs of 222 adult patients treated with miniaturized PNL. Patients were considered stone-free if no residual fragments of any size at post-operative unenhanced computed tomography scan. Patients demographics, SFRs, and CRs were reported and analyzed. Performances of nomograms were evaluated with the area under the curve (AUC).

Results

We included 222 patients, the AUCs of GSS, CROES score, and S.T.O.N.E. nephrolithometry score were 0.69 (95% confidence interval [CI] 0.61-0.78), 0.64 (95% CI 0.56-0.73), and 0.62 (95% CI 0.52-0.71), respectively. Regarding SFRs, at multivariate binomial logistic regression, only the GSS had significance with an odds ratio of 0.53 (95% CI 0.31-0.95, p=0.04). We did not find significant correlation with complications, with only a trend for GSS.

Conclusion

This is the first study evaluating nomograms in miniaturized PNL. They still show good reliability; however, our data showed lower performances compared to standard PNL. We emphasize the need of further studies to confirm this trend. A dedicated nomogram for minimally invasive PNL may be necessary.

İkinci basamak perifer devlet hastanesinde yeni uzman üroloğun erken dönem laparoskopik deneyimleri

Amaç: Devlet hizmet yükümlülüğü nedeniyle ikinci basamak perifer devlet hastanesinde görev yapan bir üroloji uzmanının ilk laparoskopik cerrahi deneyimlerinin retrospektif olarak değerlendirilmesi. Gereç ve Yöntem: Nisan 2016 – Ağustos 2018 tarihleri arasında Şanlıurfa Balıklıgöl Devlet Hastanesi Üroloji kliniğinde toplam 25 hastaya (16 erkek, 9 kadın) laparaskopik cerrahi girişim yapılmıştır. Hastalar demografik özellikler, cerrahinin uygulandığı taraf, cerrahi teknik, operasyon ve hastanede kalış süreleri, postoperatif analjezik ihtiyaç varlığı, peroperatif ve postoperatif komplikasyonlar kayıt edilmiştir. Bulgular: Çalışmaya dahil edilen hastaların yaş ortalaması 38,8 ± 11,6 yıl idi. Bunlar; basit nefrektomi (n = 10, %40), böbrek kist eksizyonu (n = 6, %24), üreterolitotomi (n = 6, %24), radikal nefrektomi (n = 1, %4), piyeloplasti (n = 1, %4) ve testis araştırılması (n = 1, %4) idi. Ortalama operasyon süresi ise 108,8 ± 31,6 dakika ve ortalama hastanede kalış süresi 3,8 ± 0,9 gün olarak tespit edildi. Tüm vakaların altısında (%24) retroperitoneal yaklaşım tercih edildi. Toplam altı (%24) hastada komplikasyon görüldü. Modifiye Clavien Komplikasyon derecelendirme sistemine göre Grade 1, 2 ve 3 komplikasyonlarının dağılımları sırasıyla dört (%66,6), bir (%16,6) ve bir (%16,6) idi. Olguların hiçbirinde grade 4 ve 5 komplikasyonları gözlenmedi. Sonuç: Laparoskopi konusunda tecrübeli merkezlerde asistanlık eğitimi alan yeni uzman ürologlar, kliniklerinde aldıkları bu eğitimi ve tecrübeyi, devlet hizmet yükümlülüğü nedeniyle gittikleri perifer devlet hastanelerinde uygulayabilir, gerek laparoskopik cerrahi ekipman temininde, gerekse yardımcı ameliyathane personeli eğitiminde öncülük yapabilirler.

Predicting the outcome of mini percutaneous nephrolithotomy using STONE nephrolithometry score-a single-center experience

To predict stone-free and complication rates following mini-percutaneous nephrolithotomy (m-PCNL) using STONE nephrolithometry score, this prospective observational study was conducted in the Department of Surgery, Urology Unit, Patan Hospital. All the patients undergoing m-PCNL were included. The cases were performed in the prone position, a single tract less than 18 French was made, and pneumatic lithotripsy was done. Stone-free rates were assessed with plain X-ray kidney, ureter, and bladder (X-ray KUB) on the first post-operative day or at 15 days follow-up. Complications within 30 days were graded using modified Clavien grading. A total of 106 patients were included in the final analysis. The overall stone-free rate was 83%. Among the individual variables, only staghorn calculus was associated with residual stone (p = 0.007). Patients who were rendered stone-free had statistically significantly lower STONE scores than those with residual stone (p < 0.001). The complication rate was 23%, and the majority were Clavien grade I complications. A higher STONE score had a greater risk of having complications but was not statistically significant (p = 0.11). STONE nephrolithometry score can predict stone complexity pre-operatively and subsequent stone-free status and thus, helps in pre-operative surgical planning and counseling for possible outcomes following m-PCNL.

Validation of the Italian version of wisconsin stone quality of life (WISQOL): a prospective Italian multicenter study

Urolithiasis is a worldwide spread condition that affects patients' Health-Related Quality of Life (HRQOL), which measurement is an important tool for routine clinical and research practice. Disease-specific HRQOL measures demonstrated to perform better in assessing the effects of specific conditions. A disease-specific questionnaire for kidney stones, the WISQOL, has been validated in different languages, but an Italian version is still missing. Our aim is to produce and validate the Italian version of WISQOL (IT-WISQOL). Patients undergoing any elective treatment for upper urinary tract stones were enrolled. A multi-step process with forward- and back-translation was used to translate WISQOL into Italian. Patients were evaluated within 15 days pre-operatively and then at 30-, 90 days post-operatively and administered both IT-WISQOL and SF-36v2. Post-operative data such as 30 days postoperative complications, late stone-related events, successful status, and stone complexity were collected. Cronbach's α was used to evaluate the internal consistency of IT-WISQOL, while Spearman's rho was used for item and inter-domain correlations and IT-WISQOL with SF-36v2 correlation. We found excellent internal consistency across all domains (α ≥ 0.88), particularly when the total score is considered (α = 0.960). Test-retest reliability showed excellent results for the total questionnaire (Pearson correlation value: 0.85). The Inter-domain association ranged from 0.497 to 0.786. Convergent validity was confirmed by a good correlation with subdomains of the SF-36v2 measures. IT-WISQOL is a reliable tool to measure HRQOL in stone patients. It shows analog characteristics if compared to English WISQOL.

The effect of COVID-19 outbreak on urological procedures for urinary stones: data from three high-volumes centers in China

China has been the first country to be affected by the COVID-19 outbreak. The pandemic resulted in significant disruption of Health Care Services worldwide, and this effect on treatments for urinary stones is currently unclear. This is the first retrospective study involving three tertiary referral centers for urolithiasis across China. We evaluated surgical volumes and peri-operative outcomes of procedures delivered for upper urinary tract stones. We compared trimester prior to restrictions for COVID-19 (October 1st, 2019 to December 31st, 2019, period A), during restrictions (February 1st, 2020 to March 31st, 2020, period B), and afterword (April 1st, 2020 to June 31st, 2020, period C). A total of 2,543 procedures have been carried out. We observed a loss of 743 cases during period B (-29.2%) and 201 during period C (-7.9%). Percutaneous surgery showed the worst reduction, with 507 mini-PCNLs delivered in period A, 168 in period B (-60.8%), and 389 (-18.3%) in period C (p = 0.001). A worst trend was shown for standard PCNLs with 84 procedures carried out in period A, 5 in period B (-95.2%), and 9 (-89.2%) in period C (p = 0.001). Retrograde surgery also decreased, from 420 cases in period A to 190 cases in period B (-54.8%). An increment was however seen in period C when 468 cases have been carried out (+ 11.4%, p = 0.008). In term of SFRs, a difference was noticed for RIRSs, being 69.2%, 80.5%, and 69.3% during three periods (p = 0.045) and semirigid ureteroscopies (90.3%, 97.1%, and 84.8%, p = 0.013). Charlson's Comorbidity Score could not show any difference between groups as well as no differences in term of post-operative complications have been noticed.

International Alliance of Urolithiasis (IAU) Guideline on percutaneous nephrolithotomy

The International Alliance of Urolithiasis (IAU) would like to release the latest guideline on percutaneous nephrolithotomy (PCNL) and to provide a clinical framework for surgeons performing PCNLs. These recommendations were collected and appraised from a systematic review and assessment of the literature covering all aspects of PCNLs from the PubMed database between January 1, 1976, and July 31, 2021. Each generated recommendation was graded using a modified GRADE methodology. The quality of the evidence was graded using a classification system modified from the Oxford Center for Evidence-Based Medicine Levels of Evidence. Forty-seven recommendations were summarized and graded, which covered the following issues, indications and contraindications, stone complexity evaluation, preoperative imaging, antibiotic strategy, management of antithrombotic therapy, anesthesia, position, puncture, tracts, dilation, lithotripsy, intraoperative evaluation of residual stones, exit strategy, postoperative imaging and stone-free status evaluation, complications. The present guideline on PCNL was the first in the IAU series of urolithiasis management guidelines. The recommendations, tips and tricks across the PCNL procedures would provide adequate guidance for urologists performing PCNLs to ensure safety and efficiency in PCNLs.

Validation of the Trifecta Scoring Metric in Vacuum-Assisted Mini-Percutaneous Nephrolithotomy: A Single-Center Experience

Background: Scoring metrics to assess and compare outcomes of percutaneous nephrolithotomy (PCNL) are needed. We aim to evaluate prevalence and predictors of trifecta in a cohort of patients treated with vacuum-assisted mini-percutaneous nephrolithotomy (vmPCNL) for kidney stones. Methods: Data from 287 participants who underwent vmPCNL were analysed. Patients’ and stones’ characteristics as well as operative data were collected. Stone-free was defined as no residual stones. The modified Clavien classification was used to score postoperative complications. Trifecta was defined as stone-free status without complications after a single session and no auxiliary procedures. Descriptive statistics and logistic regression models tested the association between predictors and trifecta outcome. Results: After vmPCNL, 219 (76.3%) patients were stone-free, and 81 (28.2%) had postoperative complications (any Clavien). Of 287, 170 (59.2%) patients achieved trifecta criteria. Patients who achieved trifecta status had smaller stone volume (p < 0.001), a higher rate of single stones (p < 0.001), shorter operative time (p < 0.01), and a higher rate of single percutaneous tract (p < 0.01) than −trifecta patients. Trifecta status decreased with the number of calyces involved, being 77.1%, 18.8%, and 4.1% in patients with 1, 2, or 3 calyces with stones, respectively (p < 0.001). Multivariable logistic regression analysis showed that stone volume (OR 1.1, p = 0.02) and multiple calyces being involved (OR 2.8 and OR 4.3 for two- and three-calyceal groups, respectively, all p < 0.01) were independent unfavourable risk factors for trifecta after accounting for age, BMI, gender, operative time, and number of access tracts. Conclusions: Trifecta status was achieved in 6 out of 10 patients after vmPCNL. Stone distribution in multiple calyceal groups and stone volume were independent unfavourable risk factors for trifecta.

The impact of Hounsfield unit-related variables on percutaneous nephrolithotomy outcomes

We aimed to identify the association between Hounsfield Unit(HU)-related variables and percutaneous nephrolithotomy (PCNL) outcomes. We enrolled patients with single renal stones (1-3 cm) who underwent single-tract PCNL between January 2014 and October 2019. Demographics and stone characteristics were retrospectively reviewed. Preoperative computerized tomography (CT) and follow-up CT within at least 3 months after PCNL were included in this analysis. Stone-free status was defined as residual stone measuring ≤ 2 mm within 3 months postoperatively. HU and cross-sectional area (CSA) were measured using the free-draw technique. We analyzed HU-related variables using logistic regression model for outcomes. Altogether, 188 out of 683 patients met the inclusion criteria. The stone-free rate (SFR) was 79.2%. There were no significant differences in age, sex, BMI, ASA class, laterality, pre-op shockwave lithotripsy, stone size, stone burden, skin-to-stone distance, and HU between the stone-free and remnant groups. CSA and HU/CSA in the stone-free and remnant groups were 94.5 ± 46.1 and 128.3 ± 98.5 (p = 0.043) and 10.1 ± 5.6 and 7.3 ± 3.4 (p = 0.001), respectively. Multivariate logistic regression analysis revealed that pelvis, ureteropelvic junction stones, and HU/CSA were independent predictors of SFR. HU did not affect PCNL outcomes. We believe that HU/CSA could be used for determining stone treatment plans and predicting outcomes.

Optimal patient position for percutaneous nephrolithotomy in horseshoe kidneys: Traditional prone or supine?

OBJECTIVE

Although it was stated that supine percutaneous nephrolithotomy (PCNL) was associated with relatively shorter surgical times and comparable success and complication rates, there is no consensus in the current literature concerning the safety and efficacy of supine PCNL in patients with horseshoe kidneys. We aimed to compare supine and prone PCNL regarding safety and efficacy in patients with horseshoe kidneys.

METHODS

Data of the patients with horseshoe kidneys who underwent PCNL for renal stones larger than 2 cm between January 2010 and May 2021 were retrospectively reviewed. The study patients were categorized as Group 1 (i.e., supine PCNL-SPCNL) and Group 2 (i.e., prone PCNL-PPCNL). Both groups were compared regarding demographic, clinical, and surgical data.

RESULTS

Sixty-five patients were included. Among these patients, 31 (47.7%) were in Group 1, while 34 (52.3%) were in Group 2. Both groups were statistically similar in terms of demographic data, stone characteristics, perioperative parameters, and complication rates (p > 0.05). There was no statistical difference in terms of additional treatment rates, stone-free rates in the postoperative second-day and third-month evaluations (p > 0.05). Mean surgical time was significantly longer in Group 2 (113 ± 17.1 min) than in Group 1 (90.6 ± 11.3 min) (p = 0.000).

CONCLUSION

Although it is traditionally performed in the prone position, the supine approach is as safe and effective as the prone approach. In addition, the supine approach is associated with significantly shorter surgical times.

Mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy and its initial clinical application

Background

To assess the outcome of the mini-track, mini-nephroscopy, mini ultrasonic probe percutaneous nephrolithotomy for upper ureteral and kidney stones.

Methods

We collected data of 53 patients (55 kidney units) who underwent mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy between September 2020 and March 2021. The study included single and upper ureteral stones from 12 kidneys, multiple stones from 28 kidneys, and staghorn stones from 15 kidneys.

Results

The mean operative duration was 50.6 min, ranging from 15 to 200 min, whereas the mean lithotripsy and stone removal time was 17.2 min (3–45 min). Moreover, the mean postoperative length of stay was 4.0 days (1–7 days). Besides, the stone-free rate (SFR) of discharge was 89.1% (49/55). The mean hemoglobin drop was 15.3 mg/dL, ranging 1–32 mg/dL. Out of the total cases, only 4 of them displayed minor complications. The outcomes of < 40 mm versus ≥ 40 mm calculi were compared by performing subgroup analysis. The results demonstrated a longer operation duration (65.2 vs. 40.2 min), higher complication rate (13.0% vs. 3.3%), and lower SFR in the ≥ 40 mm calculi subgroup.

Conclusions

In summary, mini-track, mini-nephroscopy, mini-ultrasonic probe percutaneous nephrolithotomy is an effective and safe method to treat patients with upper ureteral and kidney calculi. This is especially significant for the stone size of 20–40 mm, demonstrating excellent SFR and a lower complication rate.

Protocol for CAMUS Delphi Study: A Consensus on Comprehensive Reporting and Grading of Complications After Urological Surgery

BACKGROUND

Reproducible assessment of postoperative complications is essential for reliable evaluation of quality of care to enable comparison between healthcare centres and ensure transparent patient counselling. Currently, significant discrepancies exist in complication reporting and grading due to heterogeneous definitions and methodologies.

OBJECTIVE

To develop a standardised and reproducible assessment of perioperative complications and overall associated morbidity, to allow for the construction of a uniform language for complication reporting and grading.

DESIGN, SETTING, AND PARTICIPANTS

The 12-part REDCap-based Delphi survey was developed in conjunction with methodologist review and experienced urologist opinion. International urologists, anaesthetists, and intensive care unit specialists will be included. A minimum sample size of 750 participants (500 urologists and 250 critical care specialities) is targeted.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The survey assesses participant demographics, opinion on complication reporting and the proposed Complications After Major & Minor Urological Surgery (CAMUS) reporting recommendations, grading of intervention events using the existing Clavien-Dindo classification and the proposed CAMUS classification, and rating of various clinical scenarios. Consensus will be defined as ≥75% majority agreement. If consensus is not reached, then subsequent Delphi rounds will be performed under steering committee guidance.

RESULTS AND LIMITATIONS

Twenty-one participants completed the draft survey. The median survey completion time was 128 min (interquartile range 88-135). The survey revealed that 90% of participants believe that the current complication classification systems are useful but inaccurate, while 100% of participants believe that there is a universal demand for reporting consensus. Several amendments were made following feedback. Limitations include complexity of the proposed supplemental grades and time to completion of the survey.

CONCLUSIONS

To ensure comprehensive and comparable complication reporting and grading across centres worldwide, a conclusive uniform language for complication reporting must be created. We intend to address shortcomings of the current complication reporting and classification systems with a new CAMUS classification system developed through multidisciplinary expert consensus obtained through a Delphi survey. Ultimately, standardisation of urological complication reporting and grading may improve patient counselling and quality of care.

PATIENT SUMMARY

The reporting and grading of operative complications that occur during or after an operation and associated costs provide a means to stratify quality of patient care. Current complication reporting and classification systems are not standardised and somewhat inaccurate, and thus significantly underestimate patient morbidity and surgical risk. This Delphi survey will provide the basis for the creation of a uniform complication reporting and grading system. Our new system may allow improved reporting and grading between centres, and ultimately improve patient counselling and care.

Urologists are optimistic surgeons: prevalence and predictors of discordance between intraoperative stone-free rate and cross-sectional imaging evaluation after vacuum-assisted mini-percutaneous nephrolithotomy

PURPOSE

To assess how accurate are urologists in predicting stone-free status (SFS) after vacuum-assisted mini-PCNL (vamPCNL) compared to computed tomography (CT) and clinical predictors of discordant SFS.

METHODS

Data from 235 patients who underwent vamPCNL were analysed. Patient's demographics, stones' characteristics and operative data were recorded. SFS was evaluated intraoperatively by the treating urologist (iSFS) and with non-contrast CT 3 months after vamPCNL (ctSFS). SFS was defined as no residual stones. Stone complexity was scored with the Guy's score. Descriptive statistics and logistic regression models were used to identify clinical factors associated with discordant SFS (namely iSFS not confirmed at CT).

RESULTS

iSFS and ctSFS were 88.5% and 65.5%, respectively, with 54 (23%) cases resulting in discordant evaluation of SFS between the surgeon and CT imaging. Patients with discordant SFS had larger stone volume (p < 0.001), higher rate of multiple stones (p = 0.03) and higher rate of multiple calyceal groups affected by stones (p < 0.001) than those with concordant SFS. The use of flexible ureteroscopes to look for residual stones after lithotripsy was more frequently reported in cases with concordant SFS (p = 0.001). Multivariable logistic regression analysis revealed that stones in > 2 calyceal groups (OR 10.2, p < 0.001), Guy's score II (OR 5.8, p < 0.01) and not using flexible ureteroscopes after lithotripsy (OR 2.9, p = 0.02) were independent predictors of discordant SFS.

CONCLUSION

One out of five patients is erroneously considered SF after vamPCNL. Urologist should carefully evaluate patients with multiple calyceal stones and consider using flexible ureteroscopes to complete lapaxy of migrated fragments in order to improve their prediction of SFS.

Presence of a Novel Anatomical Structure May Cause Bleeding When Using the Calyx Access in Mini-Percutaneous Nephrolithotomy

Background

Fused renal pyramid (FRP) is a kidney anatomical structure which was first identified by us. The vascular anatomy of FRP exhibits different from that of the normal renal pyramid (NRP), manifested by the distribution of the ectopic interlobar arteries in FRP. In this study, we analyzed the effect of FRPs on bleeding when using calyx access in mini-percutaneous nephrolithotomy (PCNL).

Patients and Methods

Overall, 633 patients who underwent ultrasound-guided single-tract mini-PCNL were divided into two groups according to the puncture method used: in group A, puncture was performed through the axial direction of the renal calyx, the line from the apex of the fornix to the center of the neck plane under B-mode ultrasound guidance; and in group B, Doppler ultrasound-guided axillary puncture through calyces corresponding to NRPs when the plane of renal column blood vessels on both sides was selected or calyx puncture through the hypovascular area of the FRPs. Relevant demographic and clinical data were retrospectively analyzed.

Results

The two groups exhibited similar baseline characteristics. No significant differences were found in hemoglobin reduction, puncture site, tract size, postoperative creatinine level, or stone-free rate between the two groups (P > 0.05). Blood transfusion and embolization rates in group B were significantly lower than those in group A (P = 0.03 and 0.045, respectively). No differences were found between the two groups in terms of persistent pain, hydrothorax, fever, subcapsular hematoma, and urosepsis (P > 0.05). The overall complication rate was not significantly different between the two groups (P = 0.505).

Conclusions

FRP is a non-negligible anatomical structure that may cause hemorrhage when using calyx access. Doppler ultrasound can identify ectopic blood vessels in FRPs to reduce bleeding during calyx access in mini-PCNL procedures.

Safety Evaluation of Cervical Dorsal Instrumentation in Geriatric Patients: Experience at a Level 1 Center for Spinal Surgery-A Single Center Cohort Study

Objective

Dorsal instrumentation of the cervical spine is an established treatment in spine surgery. However, careful planning is required, particularly in elderly patients. This study evaluates early clinical outcomes in geriatric patients undergoing complex spine surgery.

Methods

In this retrospective, single center cohort study, we included all geriatric patients (aged ≥65 years) who underwent dorsal instrumentation between January 2013 and December 2020. We analyzed postoperative complications and the 30-day in-hospital mortality rate. Furthermore, the Charlson comorbidity index (CCI) and Clavien-Dindo grading system (CDG) were used to assess the patients' comorbidity burden.

Results

In total, 153 patients were identified and included. The mean age of patients was 78 years (SD ± 7). Traumatic injury (53.6%) was the most common reason for surgery. 60.8% of the patients underwent dorsal instrumentation with 3 or more levels. The most common comorbidities were arterial hypertension (64%), diabetes mellitus (22.2%), coronary heart disease and atrial fibrillation (19.6%). The most common adverse event (AE) was pneumonia (4%) and the most common surgery-related complication was wound infection (5.2%). Among patients categorized as high risk for AE (CCI > 5), 14.6% suffered a postoperative AE. In our univariate analysis, we found no risk factors for high rates of complications or mortality.

Conclusion

Our data demonstrates that older patients were at no significant risk of postoperative complications. The CCI/CDG scores may identify patients at higher risk for adverse events after dorsal instrumentation, and these assessments should become an essential component of stratification in this older patient population.

Introducing trifecta for percutaneous nephrolithotomies: a proposal for standard reporting outcomes after treatment for renal stones

BACKGROUND

In literature, the reports of outcomes after percutaneous nephrolithotomies are rather heterogeneous. This may influence studies comparison, it may also render difficult to evaluate surgical adequacy, perioperative morbidity, and patient's Quality of Life between studies. For this reason, we propose to introduce PNL-Trifecta as composite measure to standardize data reporting outcomes after percutaneous nephrolithotomies.

METHODS

We performed a prospective multicentric study on consecutive patients undergone PNL to treat renal stones between 2018 and 2020. Successful PNL-trifecta was considered achieved when procedures obtained the three following results: no residual fragments >2 mm at unenhanced CT scan at 3 months postop, no complications (defined as Clavien-Dindo Score 0) and operation carried out without placing a nephrostomy tube (tubeless or totally tubeless). We compared results of standard versus mini-PNL and between stones of different complexity (evaluated with Guy's Stone Score and S.T.O.N.E. Nephrolithometry Score). Univariate analysis was utilized to identify other factors influencing achievement of PNL-Trifecta.

RESULTS

Two hundred forty-five patients fulfilled inclusion/exclusion criteria and have been enrolled in the study (median age: 56, IQR 48-57). The overall PNL-Trifecta achievement rate was 22.85% (28.66% in the mini-PNL group and 13.68% in the standard-PNL group, P=0.010). The stone free rate, CD 0 rate and tubeless/totally tubeless rate in the mini-PNL group were 60.66%, 89.33% and 51.33% respectively. In the standard-PNL group they were 44.21%, 40.00% and 15.78% respectively. At the univariate analysis, differences between Guy's Stone Score groups in achieving PNL-Trifecta were significant (P=0.001). Also, the level of upper puncture (P=0.010) and utilization of device with active suction (P=0.002) showed statistically significant differences. Furthermore, the length of stay in the patient's group achieving Trifecta was 2.28 versus a mean length of stay of 4.64 days in the group of patients not achieving Trifecta (P=0.046).

CONCLUSIONS

We present Trifecta for PNLs as a potential tool to evaluate quality of percutaneous nephrolithotomies and to provide an instrument for an adequate standard data reporting. It can represent a valid way to assess and monitor surgeon's learning curves. It will require further external validation and studies to evaluate its correlation with mid- and long-term results and patient's health related Quality of Life outcomes.

Safety and efficacy of retrograde intrarenal surgery in primary and residual renal calculi in children

BACKGROUND

Minimal invasive approach is the current standard of care in the management of pediatric renal calculi. Current guidelines are clear with extra corporal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL) for stone size less than and greater than 20 mm respectively. Although retrograde intrarenal surgery (RIRS) is well established in adults but literature on its role, safety and efficacy in children is sparsely available.

OBJECTIVE

To share our experience of RIRS and its outcome in a pediatric population in both primary and residual calculi of size less than 20 mm.

MATERIALS AND METHODS

We retrospectively analysed data of children who underwent RIRS for either primary or residual renal calculi from January 2017 to January 2021. Children less than 5 years underwent passive ureteric dilatation with stenting preoperatively. A7.5 Fr flexible ureteroscope with an access sheath was used in all cases while performing RIRS. All the patients had a stent left in situ at the end of the procedure. Data including stone burden, number of sittings, operative time, stone-free rate (SFR) and grade of post procedural complications were analysed with appropriate statistical methods.

RESULTS

A total of 20 patients were included in this study. The median age at presentation was 9 years ranging from 9 months to 18 years. Eight patients (40%) presented with primary renal calculi and underwent RIRS directly while the rest of the 12 (60%) had residual calculi following other procedures like SWL, PCNL before undergoing RIRS. Seven patients (35%) had congenital renal anomalies. The mean stone size and operating time (OR) was 12.6 ± 3.2 mm 84.5 ± 7.2 min respectively. The post-procedural complications were seen in 4 (20%) patients in the form of Grade-1 modified Clavein classification in 3 and Grade 2 in 1 patient. The 100% stone-free rate was achieved in 80% of the cases after first attempt.

DISCUSSION

In the present series, RIRS was effective in both the types of stones (primary and residual) less than 20 mm in size, showing 100% stone free rate with maximum of two attempts. Choosing age based optimised passive ureteric dilation led to injury free access for RIRS. Overall complications remained with in low grades and are comparable to current literature. Limitations of the study include small cohort, retrospective study and the need of three anaesthesia procedures in children under 5 years of age.

CONCLUSION

RIRS is safe and effective in children with a renal stone(s) less than 20 mm and it has a high success rate in term of achieving stone free status in both primary and residual calculi.

The comprehensive complication index as a tool for reporting the burden of complications after mini-percutaneous nephrolithotomy: is it time to leave the Clavien–Dindo classification behind?

Purpose

To validate the comprehensive complication index (CCI) for mini-percutaneous nephrolithotomy (mPCNL).

Methods

Data from 287 patients who underwent mPCNL were analyzed. Complications after mPCNL were classified using both the CCI and the Clavien–Dindo classification (CDC). Descriptive statistics and linear/logistic regression analyses detailed the association between clinical predictors and mPCNL outcomes.

Results

After mPCNL, 83 (28.9%) patients had complications, of which 12 (4.2%) patients with multiple complications had a higher CCI score compared to the traditional CDC system accounting only for the highest grade. The CCI enabled a more accurate prediction of length of stay (LOS) than CDC (CCI: r = 0.32; p < 0.01 vs. CDC: r = 0.26; p = 0.01). Patients with multiple complications had higher stone volume (p = 0.02), longer operative time and LOS (all p < 0.01). A higher rate of post-operative hospital readmission (33.3% vs. 9.9%, p = 0.02) and lower rate of stone free (33.3% vs. 64.7%, p = 0.04) were found in patients with multiple complications than in those with single complication. Linear regression analysis revealed that multiple complications were associated with longer LOS (p < 0.001) after accounting for BMI and stone volume. Similarly, having multiple complications was associated with fivefold higher risk of readmission (p = 0.02).

Conclusion

The CCI is a valuable metric for assessing post-operative complications after mPCNL. The cumulative CCI is a better predictor of LOS than the CDC for mPCNL. Minor complications not captured by the highest CDC score are relevant since patients with multiple complications have longer LOS and higher rate of readmission than those with single ones.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04045-9.

Application of a three-dimensional visualization model in intraoperative guidance of percutaneous nephrolithotomy

OBJECTIVES

To establish a three-dimensional visualization model of percutaneous nephrolithotomy, apply it to guiding intraoperative puncture in a mixed reality environment, and evaluate its accuracy and clinical value.

METHODS

Patients with percutaneous nephrolithotomy indications were prospectively divided into three-dimensional group and control group with a ratio of 1:2. For patients in three-dimensional group, positioning markers were pasted on the skin and enhanced computed tomography scanning was performed in the prone position. Holographic three-dimensional models were made and puncture routes were planned before operation. During the operation, the three-dimensional model was displayed through HoloLens glass and visually registered with the patient's body. Puncture of the target renal calyx was performed under three-dimensional-image guiding and ultrasonic monitoring. Patients in the control group underwent routine percutaneous nephrolithotomy in the prone position under the monitoring of B-ultrasound. Deviation distance of the kidney, puncture time, puncture attempts, channel coincidence rate, stone clearance rate, and postoperative complications were assessed.

RESULTS

Twenty-one and 40 patients were enrolled in three-dimensional and control group, respectively. For three-dimensional group, the average deviation between virtual and real kidney was 3.1 ± 2.9 mm. All punctures were performed according to preoperative planning. Compared with the control group, the three-dimensional group had shorter puncture time (8.9 ± 3.3 vs 14.5 ± 6.1 min, P < 0.001), fewer puncture attempts (1.4 ± 0.6 vs 2.2 ± 1.5, P = 0.009), and might also have a better performance in stone clearance rate (90.5% vs 72.5%, P = 0.19) and postoperative complications (P = 0.074).

CONCLUSIONS

The percutaneous nephrolithotomy three-dimensional model manifested acceptable accuracy and good value for guiding puncture in a mixed reality environment.

SIMULTANEOUS BILATERAL ENDOSCOPIC SURGERY (SBES): IS IT READY FOR PRIME TIME?

Introduction To date, some data available in literature on simultaneous bilateral endoscopic surgery (SBES) have shown good outcomes in terms of both effectiveness and safety. The aim of this study was to report the outcomes pertaining to the effectiveness and safety of SBES performed in our series of patients with bilateral renal stones. Materials and Methods A prospective analysis of consecutive patients who underwent SBES for bilateral renal stones at our institution between June 2017 and September 2021 was performed. Routine preoperative and 1-month postoperative work-up included history, physical examination, urinalysis, urine culture, and blood tests, including the evaluation of estimated glomerular filtration rate (eGFR) using the Cockcroft-Gault equation. An abdominal non-contrast computerized tomography (NCCT) scan was performed in all cases preoperatively and 1-month postoperatively. Peri/postoperative complications were reported according to the Clavien-Dindo classification system. The primary endpoint of the study was stone-free rate (SFR), and the secondary endpoints were Clavien-Dindo complications grade 1 or higher. Results Altogether, 101 patients met the inclusion criteria and were enrolled in the study. SFR for all renal units was achieved in 82 patients (81.1%) at the 1-month follow-up. Twelve patients underwent additional flexible ureteroscopy for residual fragments, and seven asymptomatic patients with single small residual fragment were observed. Eighteen patients (17.8%) experienced Clavien-Dindo Grade I-II complications, whereas one patient (1%) experienced Clavien-Dindo Grade IIIa complication (renal arteriovenous fistula embolization under local anesthesia). Conclusions SBES is a safe and effective procedure for the treatment of bilateral renal stones. Further randomized studies with larger populations are needed to confirm these favorable outcomes of SBES to establish it as an alternative to staged surgeries in patients with bilateral renal stones. Appropriate patient selection is of paramount importance for achieving good outcomes without experiencing severe complications.

Endoscopic Combined Intrarenal Surgery Versus Percutaneous Nephrolithotomy for Complex Renal Stones: A Systematic Review and Meta-Analysis

Background: Endoscopic combined intrarenal surgery (ECIRS) adds ureteroscopic vision to percutaneous nephrolithotomy (PCNL), which can be helpful when dealing with complex renal stones. Yet, there is still no consensus on the superiority of ECIRS. We aimed to critically analyze the available evidence of studies comparing efficacy, safety, bleeding risk, and efficiency of ECIRS and PCNL. Methods: We searched for studies comparing efficacy (initial and final stone-free rate), safety (postoperative fever, overall and severe complications), efficiency (operative time and hospital stay) and bleeding risk between ECIRS and PCNL. Meta-analysis was performed. Results: Seven studies (919 patients) were identified. ECIRS provided a significantly higher initial stone-free rate, higher final stone-free rate, lower overall complications, lower severe complications, and lower rate of requiring blood transfusion. There was no difference between the two groups in terms of postoperative fever, hemoglobin drop, operative time, and hospital stay. In the subgroup analysis, both minimally invasive and conventional ECIRS were associated with a higher stone-free rate and lower complication outcomes. Conclusions: When treating complex renal stones, ECIRS has a better stone-free rate, fewer complications, and requires fewer blood transfusions compared with PCNL. Subgroups either with minimally invasive or conventional intervention showed a consistent trend.

Neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and lymphocyte-monocyte ratio (LMR) in predicting systemic inflammatory response syndrome (SIRS) and sepsis after percutaneous nephrolithotomy (PNL)

The objective of this prospective observational study was to assess the clinical significance of neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) and lymphocyte–monocyte ratio (LMR) as potential biomarkers to identify post-PNL SIRS or sepsis. Demographic data and laboratory data including hemoglobin (Hb), total leucocyte count (TLC), serum creatinine, urine microscopy and culture were collected. The NLR, LMR and PLR were calculated by the mathematical division of their absolute values derived from routine complete blood counts from peripheral blood samples. Stone factors were assessed by non-contrast computerized tomography of kidneys, ureter and bladder (NCCT KUB) and included stone burden (Volume = L × W × D × π × 0.167), location and Hounsfield value and laterality. Intraoperative factors assessed were puncture site, tract size, tract number, operative time, the need for blood transfusion and stone clearance. Of 517 patients evaluated, 56 (10.8%) developed SIRS and 8 (1.5%) developed sepsis. Patients developing SIRS had significantly higher TLC (10.4 ± 3.5 vs 8.6 ± 2.6, OR 1.19, 95% CI 1.09–1.3, p = 0.000002), higher NLR (3.6 ± 2.4 vs 2.5 ± 1.04, OR 1.3, 95% CI = 1.09–1.5, p = 0.0000001), higher PLR (129.3 ± 53.8 vs 115.4 ± 68.9, OR 1.005, 95% CI 1.001–1.008, p = 0.005) and lower LMR (2.5 ± 1.7 vs 3.2 ± 1.8, OR 1.18, 95% CI 1.04–1.34, p = 0.006). Staghorn stones (12.8 vs 3.24%, OR 4.361, 95% CI 1.605–11.846, p = 0.008) and long operative times (59.6 ± 14.01 vs 55.2 ± 16.02, OR 1.01, 95% CI 1.00–1.03, p = 0.05) had significant association with postoperative SIRS. In conclusion, NLR, PLR and LMR can be useful independent, easily accessible and cost-effective predictors for early identification of post-PNL SIRS/sepsis.

Validity of a patient-specific percutaneous nephrolithotomy (PCNL) simulated surgical rehearsal platform: impact on patient and surgical outcomes

INTRODUCTION

Simulators provide a safe method for improving surgical skills without the associated patient risks. Advances in rapid prototyping technology have permitted the reconstruction of patient imaging into patient-specific surgical simulations that require advanced expertise, potentially continuing the learning curve.

OBJECTIVES

To evaluate the impact of preoperative high-fidelity patient-specific percutaneous nephrolithotomy hydrogel simulations on surgical and patient outcomes.

MATERIALS AND METHODS

Between 2016 and 2017, a fellowship-trained endourologist performed 20 consecutive percutaneous nephrolithotomy procedures at an academic referral center. For the first ten patients, only standard review of patient imaging was completed. For the next ten patients, patient imaging was utilized to fabricate patient-specific models including pelvicalyceal system, kidney, stone, and relevant adjacent structures from hydrogel. The models were tested to confirm anatomic accuracy and material properties similar to live tissue. Full procedural rehearsals were completed 24-48 h before the real case. Surgical metrics and patient outcomes from both groups (rehearsal vs. standard) were compared.

RESULTS

Significant improvements in mean fluoroscopy time, percutaneous needle access attempts, complications, and additional procedures were significantly lower in the rehearsal group (184.8 vs. 365.7 s, p < 0.001; 1.9 vs. 3.6 attempts, p < 0.001; 1 vs. 5, p < 0.001; and 1 vs. 5, p < 0.001, respectively). There were no differences in stone free rates, mean patient age, body mass index, or stone size between the two groups.

CONCLUSION

This study demonstrates that patient-specific procedural rehearsal is effective reducing the experience curve for a complex endourological procedure, resulting in improved surgical performance and patient outcomes.