The clinical research office of the endourological society percutaneous nephrolithotomy global study: staghorn versus nonstaghorn stones

Robotic pyelolithotomy for treating large renal stone disease: a systematic review and single-arm meta-analysis

Robotic pyelolithotomy continues to gain attention as an alternative to percutaneous nephrolithotomy (PCNL) for managing complex renal stones. We performed a single-arm meta-analysis and systematically searched the English-language literature published in PubMed, Web of Science, Scopus, and Google Scholar databases up to June 2024. The risk of non-randomized bias was assessed using ROBINS-I, and the quality of the literature was assessed using MINORS (Methodological Index for Non-Randomized Studies). Merger parameters were calculated using Stata16/SE under a random-effects model. Five non-comparative single-arm studies were included in the meta-analysis. Results showed that the operative time for robotic pyelolithotomy was 168.10 min (95% CI 133.63, 202.56). The hospital stay was 2.63 days (95% CI 0.96, 4.29), and blood loss was 44.13 ml (95% CI 19.76, 68.51). The stone clearance rate was 87% (95% CI 79-93%). The incidence of minor postoperative complications (Clavien grade I-II) was 23.7% (95% CI 13.4-35.8%), and the incidence of major complications (Clavien grade ≥ III) was 7% (95% CI 0.3-20.7%).The safety and efficacy of robotic pyelolithotomy in treating complex renal stones are acceptable, but future large prospective cohort studies are needed to validate the treatment.

Risk factors of stone residual after retrograde intrarenal surgery: A prospective cohort study

BACKGROUND

Complete removal of renal stones is crucial for optimal patient outcomes, but recent studies have reported residual stones after retrograde intrarenal surgery (RIRS). This study aimed to identify the associated risk factors to improve patient management and treatment selection.

METHODS

This cohort study was conducted over 18 months at two hospitals and recruited adult patients with renal stones less than 3 cm. Preoperative assessment included medical history, physical examination, laboratory tests, and radiological imaging. Intraoperative and postoperative data collection and follow-up were conducted to evaluate surgical success and potential complications.

RESULTS

A total of 100 patients were included, with a mean age of 45.3 ± 10.7 years and a mean BMI of 26.2 ± 1.4 kg/m2. Approximately 19% of the patients had residual stones after the RIRS procedure. The RUSS score showed good diagnostic performance with an AUC of 0.843, and the optimal cut point was ⩾2.0 with a sensitivity of 52.6% and specificity of 95.1%. Independent predictors of residual stones were multiple sites (OR = 24.98; p = 0.002), multiple stones (OR = 13.62, p = 0.002), stone size of 21-30 mm (OR = 4.91, p = 0.038), lower calyx site (OR = 4.85, p = 0.033), and surgeon experience of fewer than 50 cases (OR = 6.82, p = 0.020).

CONCLUSIONS

This study identifies several factors associated with residual stones after RIRS for renal stones, including stone size, location, number, and surgeon experience. The study suggests that the RUSS score can be used as a reliable tool for predicting the likelihood of residual stones, which can help clinicians in patient selection and treatment planning.

Development of a novel percutaneous digital flexible nephroscope: its use and application

BACKGROUND

Renal calculi are one of the most frequent diseases in urology, and percutaneous nephrolithotomy (PCNL) being the gold standard for treating renal calculi larger than 2 cm. However, traditional rigid nephroscope cannot bend, presents significant limitations during PCNL. This study aims to develop a novel digital flexible nephroscope for PCNL and verify its safety and efficacy using 3D printed models and ex vivo porcine kidney models, providing new equipment for PCNL.

METHODS

Based on the determined technical parameters, the novel digital flexible nephroscope was manufactured. First, 3D-printed model and ex vivo porcine kidney models were utilized to simulate the PCNL procedures. Then, the traditional rigid nephroscope and the novel digital flexible nephroscope were utilized to simulate the PCNL procedures on 10 ex vivo porcine kidneys for comparison. We observed and recorded the renal calyces visualized and accessed by both the traditional rigid nephroscope and the novel digital flexible nephroscope.

RESULTS

In both the 3D printing and ex vivo porcine kidney models, the novel percutaneous digital flexible nephroscope smoothly entered the renal collecting system through the percutaneous renal tract. It freely changed angles to reach most target calyces, demonstrating significant advantages over the traditional rigid nephroscope.

CONCLUSION

The successful development of the novel percutaneous digital flexible nephroscope allows it to be used either independently or as an adjunct in complex stone cases, providing more effective and safer surgical equipment for percutaneous nephrolithotomy.

Successful treatment of staghorn stones with flexible ureteroscopy and thulium fiber laser (TFL) lithotripsy: initial experience with 32 cases

Purpose

To investigate the efficacy and safety of flexible ureteroscopy with thulium fiber laser lithotripsy for management of renal staghorn stones.

Materials and Methods

Thirty-two patients with staghorn stones were recruited. Stone characteristics including: width, length, volume and density were analyzed. Ablation speed, laser efficacy and laser activity were recorded. The primary outcome was to assess stone free rate after the procedure using spiral CT scan.

Results

The median stone volume was 7339 (3183–53838) mm3. Median operative and lasing time were 135 (70–200) and 117 (50–180) minutes, respectively. The mean total energy delivered was 63.9 ± 30 KJ with a median ablation speed of 1.3 (0.5–4.9) mm3/sec. Mean laser efficacy was 7.5 ± 3.6 Joules/mm3. A total of 12 complications occurred in 8 patients (25%). The median hospital stay was 7 (3.5–48) hours and 30 patients (93.7%) were discharged on the same day of surgery. After the first session, seventeen patients (53%) were stone free with no residual fragments while six (19%) patients had residuals £ 2 mm. Nine patients (28%) had residuals > 2 mm with median residual size of 4 (3–9) mm. A second intervention was required in 4 cases.The overall stone free rate after completion of treatment was 65.6%.

Conclusion

Flexible ureteroscopy with thulium fiber laser lithotripsy is a safe and effective treatment option for staghorn stones with stone free rate comparable to standard PCNL with advantages of minimal morbidity, minimal blood loss and shorter hospital stay.

Prediction of percutaneous nephrolithotomy outcomes and flexible ureteroscopy outcomes using nephrolithometry scoring systems

BACKGROUND

Kidney stones account for a high proportion of urological emergencies. The main objective of this paper is to evaluate the predictive ability of five scoring systems for overall stone-free status and postoperative complications after percutaneous nephrolithotomy and retrograde ureteroscopy.

MATERIALS AND METHODS

This study retrospectively analysed 312 cases of kidney stone patients between January 2021 and May 2022 at our centre. Multivariate logistic regression as well as ROC curves were applied to determine the ability to evaluate each scale to predict stone-free rates and postoperative complications.

RESULTS

179 patients have undergone PCNL. After multivariate logistic regression, the S.T.O.N.E score and history of ipsilateral renal surgery were predictive of stone-free status, and the predictive power of the S.T.O.N.E score was higher than that of history of ipsilateral renal surgery. Grade 1 complications were considered to be related to Guy's score and grade 2 complications were considered to be related to history of diabetes mellitus. 133 patients have undergone f-URS. After multivariate logistic regression analysis, the modified S-ReSC score, RUSS score, and R.I.R.S score were predictive of stone-free status, with the R.I.R.S score being the strongest predictor. Evidence of grade 2 complications was considered to be related to abnormal renal function.

CONCLUSION

For PCNL, the S.T.O.N.E score had the best efficacy in predicting stone-free status, and the Guy's score had the best efficacy in predicting postoperative complications; for f-URS, the R.I.R.S score had the best efficacy in predicting stone-free status, and no scoring system predicted postoperative complications.

Antegrade flexible ureteroscopy-assisted percutaneous nephrolithotomy for staghorn calculi: a prospective randomized controlled study

The aim is to compare the efficacy and safety between single percutaneous nephrolithotomy (sPNL) and antegrade flexible ureteroscopy-assisted percutaneous nephrolithotomy (aPNL) for the treatment of staghorn calculi. A prospective randomized controlled study was conducted at the Second Hospital of Tianjin Medical University. A total of 160 eligible patients were included, with 81 in the sPNL group and 79 in the aPNL group. The study first compared the overall differences between sPNL and aPNL. Then, the patients were divided into two subgroups: Group 1 (with less than 5 stone branches) and Group 2 (with 5 or more stone branches), and the differences between the two subgroups were further analyzed. The results showed that aPNL had a higher stone-free rate (SFR) and required fewer percutaneous tracts, with a shorter operation time compared to sPNL (P < 0.05). Moreover, aPNL significantly reduced the need for staged surgery, particularly in patients with 5 or more stone branches. Moreover, there were no significant differences in the changes of hemoglobin levels and the need for blood transfusions between the sPNL and aPNL groups, and the incidence of multiple tracts was lower in the aPNL group. The two groups showed comparable rates of perioperative complications. We concluded that aPNL resulted in a higher SFR for staghorn calculi, and required fewer multiple percutaneous tracts, reduced the need for staged surgery, and had a shorter operative time than PNL alone, especially for patients with 5 or more stone branches. Furthermore, aPNL did not increase the incidence of surgical complications.

Laparoscopic pyelotomy combined with ultrasonic lithotripsy via a nephroscope for the treatment of complex renal stones

The purpose of the study was to introduce a novel surgical approach of combining laparoscopic pyelotomy with ultrasonic lithotripsy via a nephroscope for the treatment of complex renal stones. Between May 2021 and April 2023, 32 patients underwent laparoscopic pyelotomy combined with ultrasonic lithotripsy via a nephroscope and their perioperative variables were retrospectively collected and outcomes were assessed. Dissection and incision of the anterior renal pelvis wall was performed via a laparoscope. A 19.5 F nephroscope was introduced into the renal pelvis through a laparoscopic trocar from the incision. Stones were fragmented and sucked out using a 3.3 mm ultrasonic probe placed through the nephroscope. All operations were completed successfully and the stone-free rate at 3 days after operation was 87.5% (28/32). Four (12.5%, 4/32) patients with staghorn stones had a small residual stone in the lower calyx after operation and did not require reintervention. No patient required perioperative transfusion and four (12.5%, 4/32) patients with struvite stones developed postoperative fever, which was successfully treated with intravenous antibiotics. The mean follow-up time was 14.0 ± 7.2 months, with no patient developing long-term complications. This approach offers a safe and effective treatment option for complex renal stones, as the method exhibits a high clearance rate with few complications.

The experience of a tertiary referral center with laparoscopic pyelolithotomy for large renal stones during 18 years

This study aimed to evaluate the outcomes of laparoscopic pyelolithotomy, including its efficacy and feasibility in treatment of large renal stones. All patients who underwent laparoscopic pyelolithotomy operations in a referral center were enrolled from 2003 to 2020. The final analysis included 436 patients. The total stone free rate was 88.3% and the stone-free rate for staghorn/multiple stones versus other types of stones was 81% vs. 91% (P = 0.002). Likewise, the total operation duration was 158 ± 50 and the operation duration for staghorn/multiple stones versus other types of stones was 171 ± 51 min vs. 153 ± 49 min (P < 0.001). The operation duration (169 ± 51 vs. 155 ± 58 vs. 155 ± 42 min) and hospitalization (4.5 ± 2.3 vs. 4.0 ± 2.2 vs. 3.6 ± 1.8) decreased with increasing the surgeons' experience over time. The outcomes of laparoscopic pyelolithotomy for children versus adults versus geriatric patients and in patients with normal versus abnormal kidney anatomy did not reveal statistically significant differences. Laparoscopic pyelolithotomy could be employed as an alternative surgical approach for patients with large kidney stones of any age or with kidney abnormalities provided that appropriate expertise is available to carry out the procedure.

Needle-perc-assisted endoscopic surgery (NAES) for patients with complicated solitary kidney stones: a prospective randomized study from a single center

PURPOSE

The goal of this study is to compare traditional percutaneous nephrolithotomy (PCNL) and needle-perc-assisted endoscopic surgery (NAES) in the treatment of complicated solitary kidney stones via a single-center randomized controlled prospective study.

METHODS

A total of patients with complex (Guy's score II-IV) solitary kidney stones between July 2019 to June 2022 were enrolled in the study. Participants were stratified into two groups: needle-perc-assisted endoscopic surgery group (group A) and traditional PCNL group (group B). All procedures were finished by X-ray free technique. The clinical characteristics and outcomes were analyzed.

RESULTS

A total of 90 (44 in Group A and 46 in Group B) patients were finally included in our study. There were no statistically differences in terms of gender, age, body mass index (BMI), stone burden between two groups. The mean operative duration of Group A was significant higher than group B (95.1 ± 21.4 min vs 72.5 ± 29.5 min, p=0.02). The 1-month stone-free rate (SFR) was significant higher in Group A than B (90.9% vs 73.9%, p=0.03). A less hemoglobin drop (p=0.01), shorter postoperative in-hospital day (p=0.04), and lower severe complication (Clavien-Dindo III and above) rates (p=0.03) were observed in Group A.

CONCLUSION

For patients with solitary kidney stones, NAES technique provides a higher one-session SFR, a better renal function recovery and compared with traditional PCNL.

A multicenter study on the application of artificial intelligence radiological characteristics to predict prognosis after percutaneous nephrolithotomy

Background

A model to predict preoperative outcomes after percutaneous nephrolithotomy (PCNL) with renal staghorn stones is developed to be an essential preoperative consultation tool.

Objective

In this study, we constructed a predictive model for one-time stone clearance after PCNL for renal staghorn calculi, so as to predict the stone clearance rate of patients in one operation, and provide a reference direction for patients and clinicians.

Methods

According to the 175 patients with renal staghorn stones undergoing PCNL at two centers, preoperative/postoperative variables were collected. After identifying characteristic variables using PCA analysis to avoid overfitting. A predictive model was developed for preoperative outcomes after PCNL in patients with renal staghorn stones. In addition, we repeatedly cross-validated their model's predictive efficacy and clinical application using data from two different centers.

Results

The study included 175 patients from two centers treated with PCNL. We used a training set and an external validation set. Radionics characteristics, deep migration learning, clinical characteristics, and DTL+Rad-signature were successfully constructed using machine learning based on patients' pre/postoperative imaging characteristics and clinical variables using minimum absolute shrinkage and selection operator algorithms. In this study, DTL-Rad signal was found to be the outstanding predictor of stone clearance in patients with renal deer antler-like stones treated by PCNL. The DTL+Rad signature showed good discriminatory ability in both the training and external validation groups with AUC values of 0.871 (95% CI, 0.800-0.942) and 0.744 (95% CI, 0.617-0.871). The decision curve demonstrated the radiographic model's clinical utility and illustrated specificities of 0.935 and 0.806, respectively.

Conclusion

We found a prediction model combining imaging characteristics, neural networks, and clinical characteristics can be used as an effective preoperative prediction method.

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.

Robotic Surgery for Stone Disease

PURPOSE OF REVIEW

To evaluate recent literature regarding the role of robotic technology in the treatment of nephrolithiasis with particular attention to complex technical procedures.

RECENT FINDINGS

Robotic platforms including single-port robotics have been widely adopted in urological practice for the treatment of both malignant and benign conditions and has led to an expansion of the utilization of robot-assisted surgery to tackle challenging clinical scenarios such as bladder neck reconstruction, upper urinary tract reconstruction, and more recently complex stone disease. Presently, the American Urological Association guidelines on the surgical management of stones advise against using robotic, open, or laparoscopic techniques as a first-line approach for most patients with stone disease with the exception for patients with anatomical abnormalities, large or complex stones, or patients requiring a concomitant reconstructive operation. Clinicians have demonstrated the safety and feasibility of surgical robotics in the treatment of stone disease for a variety of operations including robotic pyeloplasty, pyelolithotomy, ureterolithotomy, and surgical interventions in urinary diversions as well as novel technologies for robotic ureteroscopy and percutaneous access. Numerous clinicians have demonstrated the safety and feasibility of using robot-assisted surgery to treat nephrolithiasis, mainly in complex renal anatomy. Further research is necessary to identify the best candidates for utilization of robotics in complex stone disease, and further technological developments will continue to further advance the use of these platforms in the treatment of nephrolithiasis.

Impact of Vacuum-Assisted Mini-Endoscopic Combined Intrarenal Surgery for Staghorn Stones: Analysis of Perioperative Factors of Postoperative Fever and Stone-Free Status

Background and Objective: This retrospective cohort study aimed to evaluate the clinical outcomes of vacuum-assisted mini-endoscopic combined intrarenal surgery (vmECIRS) for staghorn stones. Patients and Methods: We analyzed a total of 61 cases treated with initial vmECIRS using 14F/16F ClearPetra^® percutaneous sheaths for staghorn stones. We primarily measured complications and stone-free rates (SFRs) to evaluate the safety and efficiency of vmECIRS. In addition, pre- and intraoperative factors in patients who experienced postoperative fever >38°C and achieved an initial stone-free status were evaluated. Results: The percentages of staghorn stones were 36.1% and 63.9% for complete and partial stones, respectively. The median stone volume was 8.48 cm³. The median operation time was 117 minutes, and the mean number of procedures was 1.54. Regarding postoperative complications, postoperative fever >38°C was reported in 18 patients (29.5%). The initial and final SFRs were 50.8% and 91.8%, respectively. Among patients with emerging fever >38°C, positive urine culture was the only significant risk factor in the multivariate analysis (odds ratio [OR], 7.500; 95% confidence interval [CI], 1.772-31.751; p = 0.006). Moreover, for achieving initial stone-free status, body mass index and stone volume were significant risk factors in the multivariate analysis (OR, 0.872; 95% CI, 0.776-0.980; p = 0.021; and OR, 0.882; 95% CI, 0.784-0.994; p = 0.039, respectively). Conclusions: These findings suggest that vmECIRS is safe and effective for treatment of staghorn stones. Although current guidelines suggest that percutaneous nephrolithotomy is the gold standard surgical technique for staghorn stones, vmECIRS could also be a treatment strategy. The Clinical Trial Registration number (ID: 2022-05-17-1).

Ultrasound-guided percutaneous nephrolithotomy in patients with retrorenal colon: a single-center experience

BACKGROUND

Retrorenal colon is a risk factor for colonic injury during percutaneous nephrolithotomy (PCNL). Our aim in this study is to report the feasibility and outcomes of ultrasound-guided percutaneous nephrolithotomy in patients with preoperatively known retrorenal colon by cross-sectional imaging.

METHODS

In this prospective study, all patients with large renal stones and retrorenal colon in preoperative cross-sectional imaging from September 2020 to January 2022 who were candidates for PCNL were enrolled. Percutaneous access was established by ultrasonography guidance by the freehand method with dilation of the tract by a combination of fluoroscopy and ultrasonography.

RESULTS

Of the 1123 patients (Male = 760 and Female = 363) who underwent PCNL, 13 patients (Male = 6 and Female = 7) had retrorenal colon in the preoperative computed tomography. The series included two patients with malrotated kidneys. Complete stone clearance was achieved in 11 patients. Patients were followed up for at least 3 months. No serious postoperative complications were observed during follow-up.

CONCLUSION

In selected patients and experienced hands, ultrasound-guided PCNL can be an alternative option for the treatment of patients with large renal stones who have retrorenal colon in cross-sectional imaging.

Is There Still a Place for Percutaneous Nephrolithotomy in Current Times?

Background: Percutaneous nephrolithotomy (PCNL) and its miniaturized modifications are usually considered the standard surgical options for large (>20 mm) staghorn and infected stones. Moreover, PCNL is a viable alternative to retrograde intrarenal surgery (RIRS) for smaller stones (<20 mm) in the presence of anatomical malformations or inaccessible lower pole stones. However, due to the advancements in laser and scope technology, RIRS is expanding its indications with the potential benefits of lower complications and a shorter hospital stay. Methods: A literature search using the PUBMED database from inception to June 2022 was performed to explore the current role of PCNL in endourology. The analysis involved a narrative synthesis. Results: PCNL confirmed its role in the treatment of large and complex stones; moreover, miniaturized PCNL has become more competitive, gaining space among classic indications of flexible ureteroscopy. Conclusions: considering all the evaluated subgroups, we can conclude that PCNL is an old fascinating procedure and is here to stay.

Renal pelvis mucosal artery hemorrhage after percutaneous nephrolithotomy: a rare case report and literature review

BACKGROUND

Following a percutaneous nephrolithotomy (PCNL) procedure, the most common complications are considered to be intraoperative and postoperative bleeding. Many patients with postoperative bleeding can be treated conservatively, causing the perirenal hematoma to resolve spontaneously. The major causes of severe postoperative bleeding are pseudoaneurysms, arteriovenous fistula, and segmental arterial injury. Typically, the first choice of treatment to manage severe bleeding complications is selective angioembolization (SAE) because of the very high success rate associated with this procedure.

CASE PRESENTATION

This clinical case involves a 56-year-old man who underwent dual-channel PCNL treatment after diagnosing a left kidney staghorn stone and urinary tract infection. The operation was successful, with no apparent signs of bleeding. Tests revealed continued decreasing hemoglobin levels following the procedure. After the conservative treatment failed, renal angiography was performed immediately, indicating renal pelvis mucosal artery hemorrhage. In the three hours post-surgery, the SAE still failed to prevent bleeding. Further discussions led to formulating a new surgical plan using a nephroscope to enter the initial channel where hemostasis began. The hemostasis origin was found precisely in the mucosal artery next to the channel during the operation and was successfully controlled.

CONCLUSIONS

This case reveals there is poor communication and inadequate discussions about the potential failures of an SAE procedure. Swift clinical decision-making is imperative when dealing with high-level renal trauma to prevent delays in surgery that can threaten the safety of patients.

The safety and efficiency of a 1470 nm laser in obtaining tract hemostasis in tubeless percutaneous nephrolithotomy: a retrospective cross-sectional study

Objective

It is challenging to perform a tubeless percutaneous nephrolithotomy (PNL) in patients with tract bleeding. The present study was designed to study the safety and efficacy of the 1470 nm laser for hemostatic completion in tubeless PNL patients with tract bleeding.

Patients and Methods

Between January 2020 and October 2021, 120 patients were retrospectively included and divided into two groups. The hemostasis group included 60 patients receiving tubeless PNL, in which a 1470 nm laser was used to manage tract bleeding. The other group included 60 patients receiving tubeless PNL in which the hemostasis procedure was not performed, serving as the control group. The differences in the patients’ demographic characteristics, procedural information, and posttreatment outcomes between the two groups were statistically compared.

Results

The differences associated with sex, age, weight, body mass index, urine culture, stone burden, calyx of puncture, degree of hydronephrosis and comorbidities between the two groups were not statistically significant. Compared with the control group, the hemostasis group showed greatly reduced blood loss (0.61 ± 0.31 vs. 0.85 ± 0.46 g/dL) and decreased postoperative hospitalization duration (2.83 ± 0.81 vs. 4.45 ± 0.91 days). The differences in operative time, stone-free rate, Visual Analogue Score and postoperative complications between the two groups were not statistically significant. In the subgroup analysis, the obese patients and patients with moderate to severe hydronephrosis in the hemostasis group also showed a significantly less blood loss (0.51 ± 0.22 vs. 0.83 ± 0.48 g/dL; 0.54 ± 0.27 vs. 0.85 ± 0.47 g/dL, respectively) and shorter length of postoperative hospitalization (2.62 ± 0.51 vs. 4.47 ± 1.19 days; 2.97 ± 0.63 vs. 4.41 ± 0.91 days, respectively) than those in the control group.

Conclusions

Our results demonstrated that 1470 nm laser is a safe, feasible and effective method to obtain tract hemostasis in tubeless PNL.

Application of a novel computer-assisted surgery system in percutaneous nephrolithotomy: A controlled study

BACKGROUND

Most complex renal stones are managed primarily with percutaneous nephrolithotomy (PCNL). However, PCNL is still a great challenge for surgeons because of poor comprehension on complex adjacent structures. Novel techniques are required to assist in planning and navigation.

AIM

To apply and evaluate the Hisense computer-assisted surgery (CAS) system in PCNL.

METHODS

A total of 60 patients with complex renal stones were included. Thirty patients in the CAS group had three-dimensional (3D) virtual models constructed with the CAS system. The model assisted in planning and navigating in the CAS system. Thirty patients in the control group planned and navigated as standard PCNL, without the application of the CAS system. Success rate of one attempt, operation time, initial stone-free rate, decrease in hemoglobin, and complications were collected and analyzed.

RESULTS

There were no statistically significant differences in the baseline characteristics or planning characteristics. The success rate of one puncturing attempt (90% vs 67%, P = 0.028) and the initial stone-free rate (87% vs 63%, P = 0.037) were significantly higher in the CAS group. However, there were no statistically significant differences in the operation time (89.20 ± 29.60 min vs 92.33 ± 33.08 min, P = 0.859) or in the decrease in hemoglobin (11.07 ± 8.32 g/L vs 9.03 ± 11.72 g/L, P = 0.300) between the CAS group and the control group. No statistically significant differences in the incidence of complications (Clavien-Dindo grade ≥ 2) were found.

CONCLUSION

Compared with standard PCNL, CAS-assisted PCNL had advantages in terms of the puncturing success rate and stone-free rate. The Hisense CAS System was recommended to assist in preoperative planning and intraoperative navigation for an intuitive, precise and convenient PCNL.

Factors Affecting Transfusion during Percutaneous Nephrolithotomy: A Retrospective Study of 665 Cases

Objective

This study was designed to evaluate the aspects that affect transfusion following percutaneous nephrolithotomy (PCNL). Patients and Methods. From 2016 to 2019, 665 patients underwent PCNL for the removal of renal calculi at our center (Department of Urology, Shanghai Xu-hui Central Hospital). Complications, including hemorrhages, have been reported. Twenty-three patients (3.5%) have received a blood transfusion, and 12 (1.9%) patients were treated with hyper-selective embolization. We focused on the influencing factors related to postoperative blood transfusion. The factors analyzed were age, sex, hypertension, diabetes, serum creatinine level, preoperative hemoglobin, and the use of anticoagulants or antiplatelet medications; renal and stone factors (i.e., previous surgery, abnormal anatomy, stone side, stone burden, and stone type); and surgical features (i.e., access number, the calyx of puncture, and stone-free rate). These data were analyzed for the presence of bleeding.

Results

Among individual factors, preoperative hemoglobin level (p < 0.001) and urinary infections (p < 0.001) were significantly correlated with blood transfusion. Among renal and stone factors, only a history of open surgery was significantly correlated with blood transfusion (p < 0.05). Stone type or stone burden did not correlate with transfusion. Furthermore, no statistically significant correlation was found between surgical features and bleeding, and a lower stone-free rate was reported for the transfusion group.

Conclusion

The obtained results demonstrated that PCNL is a safer surgical procedure in a high-volume center; however, anemic conditions, infections, and history of open surgery will significantly increase the transfusion rate following PCNL.

Using Intraoperative Portable CT Scan to Minimize Reintervention Rates in PCNL: A Prospective Trial

BACKGROUND AND PURPOSE

More than 40% of patients undergoing PCNL are left with residual stone fragments and often require secondary procedures. Portable CT (PCT) technology allows surgeons to obtain intraoperative cross-sectional imaging, identify and extract residual stones immediately, and thereby reduce the need for subsequent procedures. This prospective trial evaluates how incorporation of PCT during PCNL affects perioperative outcomes.

PATIENTS AND METHODS

We prospectively enrolled eligible patients undergoing initial PCNL for this trial (n=60), which entailed a single intraoperative CT-abdomen and ipsilateral antegrade ureteroscopy when the surgeon felt stone treatment was visually complete. If residual fragments were identified, the surgeon continued nephroscopy to find and remove them; if not, the procedure was concluded. These patients were compared to a retrospective cohort (n=174) who underwent initial PCNL with post-operative imaging performed the following day.

RESULTS

The two cohorts had similar demographic properties and stone characteristics, and location of percutaneous access. In the prospective arm, 50% of intraoperative PCT scans identified residual fragments, prompting continuation of surgery to remove them. This cohort had significantly higher stone-free rate (82% vs. 36%, p<0.01), lower rate of planned reintervention (7% vs. 32%, p<0.01), lower rate of urgent presentation with ureteral obstruction (0% vs. 7%, p=0.04), lower total CT-based effective radiation dose (8.4 vs. 14.6 mSv, p<0.01), and shorter length of stay (2.3 vs. 3.5 days, p<0.01) when compared to the retrospective cohort that did not use intraoperative PCT.

CONCLUSIONS

Obtaining an intraoperative portable CT scan during PCNL can substantially improve perioperative outcomes. Further evaluation of this modality through a randomized-controlled trial is warranted.

Totally tubeless single access tract mini-percutaneous nephrolithotripsy in treatment of large burden > 2-cm and/or complex renal stones: a case series of 62 patients

Background

Limited literature has focused on the use of totally tubeless mini-percutaneous nephrolithotomy (PCNL) for the treatment of large renal stones. We present our findings of treating patients with large and/or complex renal stones using single renal access totally tubeless mini-PCNL.

Methods

From March 2018 to May 2021, 62 consecutive cases in which single tract totally tubeless mini-PCNL was used to treat complex renal stones were enrolled, all with calculi > 2 cm. All procedure of puncture and dilation were guided by fluoroscope. The complexity of stones was assessed according to the Guy’s Scoring System (GSS). The surgical duration, length of hospital stay, analgesia requirement, stone-free rate, and perioperative morbidity were assessed.

Results

The mean preoperative stone burden was 36.69 ± 19.76 mm (above 2 cm in all cases), mean surgical duration was 61.93 ± 40.84 min (range 15–180 min), and mean hematocrit reduction was 4.67 ± 2.83%. Postoperative Nalbuphine was used in 6 patients. The mean length of stay was 2.46 ± 1.19 days (range 2–8 days), and the postoperative stone-free rate was 83.9% (52/62), and 87.1% (54/62) after auxiliary ESWL. The overall complication rate was 14.5%, the majority of complications being postoperative transient fever.

Conclusion

For the treatment of large bursen > 2 cm and/or complex renal stones, totally tubeless single tract mini-PCNL ensures a feasible SFR, low morbidity and short hospital stay. According to the low complication rate in our study, the totally tubeless manner was not associated with an increased risk of postoperative morbidity, and patients benefited from decreased postoperative analgesics use.

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.

Endoscopic combined intrarenal surgery in prone split-leg and inclined supine positions to treat renal cast and multiple calyx stones

This Invited Commentary discusses the following article:

Mulay A, Mane D, Mhaske S, Shah AS, Krishnappa D, Sabale V. Supine versus prone percutaneous nephrolithotomy for renal calculi: Our experience. Curr Urol 2022;16 (1):25-29. doi: 10.1097/CU9.0000000000000076.

Trends of percutaneous nephrolithotomy in Saudi Arabia

Objective:

The objective of the study was to present the current practice patterns on percutaneous nephrolithotomy (PCNL) in Saudi Arabia and to compare it with the international patterns and to observe the adherence to the guidelines.

Materials and Methods:

A survey consisting of 28 questions was sent to urologists working in Saudi Arabia using a Google Forms questionnaire. The questioner covered most aspects of performing PCNL starting from preparing the patient till discharging him.

Results:

One hundred and thirty-two replied to the survey. Almost 70.2% performed PCNL and 59.1% of them learned PCNL during residency. The access was obtained by the urologists in 80.3% from the participants, 68.2% of them uses fluoroscopic guidance for the puncture. The majority (80.3%) perform PCNL in the prone position. Nearly 69.7% use the balloon dilators and 16.7% use the Amplatz dilators. For kidney drainage, 60.6% place a nephrostomy tube and a double-J stent (DJ stent) together and 4.5% perform tubeless PCNL (DJ stent only). About 45.5% stated that the introduction of flexible ureteroscopy decreased the rate of doing PCNL for >20%.

Conclusions:

Data obtained from a group of urologists in Saudi Arabia showed that the majority of urologists practicing in Saudi Arabia perform PCNL. They usually learn PCNL during residency. We observe that the majority of urologists attach to the original patterns in PCNL, i.e., they predominantly prefer the prone position and use fluoroscopy to gain the PCNL access. Furthermore, the data showed that new trends in PCNL did not gain a lot of momentum as few practices miniaturized PCNL and tubeless PCNL. The majority use balloon dilators and combined ultrasonic/pneumatic lithotripters. The complication rate encountered by the participants is concomitance with the published international figures. The introduction of flexible ureteroscopy highly decreased the rate of doing PCNL for most urologists.

Pneumatic Lithotripsy versus Holmium Laser Lithotripsy in Percutaneous Nephrolithotomy for Patients with Guy's Stone Score Grade IV Kidney Stone

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the efficacy and reliability of holmium (Ho:YAG) laser lithotripsy (HLL) and pneumatic lithotripsy (PL) in percutaneous nephrolithotomy (PCNL) in the treatment of patients with Grade IV kidney stones based on Guy's Stone Score.

STUDY DESIGN/MATERIALS AND METHODS

This retrospective study included 103 patients with Grade IV kidney stones out of 440 patients who underwent PCNL through HLL and PL in Second Affiliated Hospital of Shantou University Medical College, China, from January 2016 to December 2018. We analyzed preoperative, intraoperative, and postoperative variables of the patients to evaluate the efficacy and reliability of PCNL procedures.

RESULTS

Patients were categorized as Grade I, II, III, and IV, and the patients of each grade were 85 (19.32%), 39 (8.86%), 213 (48.41%), and 103 (23.41%), respectively. In Grade IV, the total operative time (min) for the PL and HLL groups was 137.7 ± 47.79 and 134.27 ± 53.38, respectively (p = 0.744). The variation in laboratory examination values including ΔHGB (g/L), ΔHCT, ΔPCT, and ΔCr (μmol/L) for PL and HLL groups was 19 ± 11.23/12 ± 15.42 (p = 0.012), 0.057 ± 0.034/0.038 ± 0.045 (0.009), 0.027 ± 0.034/0.026 ± 0.034 (0.702), and 3.07 ± 17.4/20.54 ± 65.93 (0.692), respectively. The postoperative hospitalization day was 8.94 ± 4.2 and 7.73 ± 2.75 (p = 0.015), respectively. As for the stone-free rate (SFR), the SFRs for PL and HLL were 48.15% (n = 39/81) and 59.09% (n = 13/22) (p = 0.363), respectively.

CONCLUSIONS

HLL showed a comparable advantage of not only decreased postoperative hemoglobin and hematocrit but also fewer postoperative hospitalization days. Based on the results of our retrospective study, for those Grade IV kidney stone patients who have a risk of bleeding before PCNL operation, HLL can be a considerable treatment option. Besides, in consideration of reducing human care cost, HLL which showed fewer hospitalization days, would be more welcome by patients.

Non-papillary percutaneous nephrolithotomy for treatment of staghorn stones

BACKGROUND

The aim of this study was to evaluate the non-papillary puncture for Percutaneous Nephrolithotomy (PCNL) for the treatment of staghorn stones in terms of safety and efficacy.

METHODS

Data of 53 patients undergoing PCNL for staghorn stones were retrospectively collected from January 2015 to December 2019. A non-papillary puncture was performed with a two- step track dilation technique up to 30Fr. A 26 Fr semirigid nephroscope and an ultrasonic lithotripter with integrated suction (Swiss Lithoclast master, EMS S.A, Nyon, Switzerland) were used for the treatment. Demographics and perioperative data were retrospectively gathered from an institutional board approved database.

RESULTS

The average stone size was 60.1±16.1 mm. Mean operative time was 54.57±14.83 minutes, while mean time using fluoroscopy was 2.67±1.02 minutes. Mean number of accesses was 1.2 (a total of 64 accesses). Flexible nephroscope was never used. Primary stone-free rate after PCNL was 81.1% (43 patients). Mean hemoglobin drop was 1.6±1.86 gr/dL. Overall patient stay was 3.94±0.82 days, while overall complication rate was 20.7% (11 patients), with only one patient requiring blood transfusion due to pseudoaneurysm.

CONCLUSIONS

The use of non-papillary access for PCNL in the treatment of staghorn stones resulted in promising results in terms of stone-free rate, operating time, complication rate, hemoglobin drop and reduced the number of percutaneous tracts. These parameters of the current investigation were directly comparable to current literature. The safety and efficacy of a non-papillary approach for the treatment of staghorn stones could be advocated.

The impact of anterior calyceal stones on the outcomes of percutaneous nephrolithotomy for complex kidney stones: a comparative study

BACKGROUND

This study aimed to evaluate the possible effect of anterior calyceal stones on the surgical outcomes of percutaneous nephrolithotomy.

METHODS

Consecutive patients with complex kidney stones from 2012 to 2020 were evaluated retrospectively. In total, 219 patients were divided into 2 groups based on the presence of anterior calyceal stones (group 1; N.=89) or not (group 2; N.=130). The groups were compared in terms of surgical outcomes (i.e., stone-free rate [SFR], operation time, and hemoglobin drop) and complications.

RESULTS

The patient demographics and stone characteristics were similar between the groups. Multiple access was more frequently done in group 1 than it was in group 2 (47.2% vs. 30.8%; P=0.014), and the SFR was lower in group 1 (51.7%) than it was in group 2 (67.7%; P=0.017). Of the anterior calyceal stones in group 1, 42.6% could not be cleaned. However, when excluding patients who have only anterior residual stones from the statistical analysis, the groups had similar SFRs (68.5% vs. 67.7% for group 1 and group 2, respectively).

CONCLUSIONS

The presence of complex kidney stones with anterior calyceal extension are associated with higher residual stones rates in the anterior calyx. Also, it increases multiple access, the operation time, and level of hemoglobin drop.

A comparative study of endoscopic combined intrarenal surgery (ECIRS) in the galdakao-modified supine valdivia (GMSV) position and minimally invasive percutaneous nephrolithotomy for complex nephrolithiasis: a retrospective single-center study

The aim of this research is to compare the efficiency and safety between endoscopic combined intrarenal surgery (ECIRS) in the Galdakao-modified Supine Valdivia (GMSV) position and minimally invasive percutaneous nephrolithotomy (Mini-PCNL) in a single session for the treatment of complex nephrolithiasis. 140 consecutive patients who were diagnosed with multiple pyelocaliceal stones or staghorn renal calculi were enrolled and reviewed retrospectively. Demographic, clinical information and surgical outcomes were collected and analyzed. Demographic variables and stone characteristics did not show statistically differences. Over 80% of the patients were diagnosed with multiple pyelocaliceal stones, while the remainders were branched renal calculi. Over half of the patients were classified into medium and high Seoul National University Renal Stone Complexity scoring system (S-ReSC) score groups. The stone free rate (SFR) in the single session was significantly higher in the ECIRS group than in the Mini-PCNL group (88.06% vs. 66.67%, P = 0.003). The subgroup analysis revealed that ECIRS was more efficacious than Mini-PCNL for complex renal calculi with medium and high S-ReSC scores (P = 0.002). A nonsignificant but relatively lower postoperative complication rate was noted in the ECIRS group (7.5 vs. 16.0%, P = 0.12). With the exception of postoperative hospitalization days (P < 0.001), significant difference was not detected between the two groups for other procedure-related information. ECIRS in the GMSV position is an effective and safe treatment especially for medium and severe complex nephrolithiasis, with significant higher SFR in the single session and relatively low procedure-associated morbidity compared to Mini-PCNL.

Percutaneous nephrolithotomy for staghorn calculi: Troubleshooting and managing complications

Staghorn calculi comprise a unique subset of complex kidney stone disease. Percutaneous nephrolithotomy (PCNL) is the gold standard treatment for staghorn stones. Despite continuous refinements to the technique and instrumentation of PCNL, these stones remain a troublesome challenge for endourologists and are associated with a higher rate of perioperative complications than that for non-staghorn stones. Common and notable intraoperative complications include bleeding, renal collecting system injury, injury of visceral organs, pulmonary complications, thromboembolic complications, extrarenal stone migration, and misplacement of the nephrostomy tube. Postoperative complications include infection and urosepsis, bleeding, persistent nephrocutaneous urine leakage, infundibular stenosis, and death. In this review, we report recommendations regarding troubleshooting measures that can be used to identify and characterize these complications. Additionally, we include information regarding management strategies for complications associated with PCNL for staghorn calculi.

Preoperative imaging in staghorn calculi, planning and decision making in management of staghorn calculi

Objective

Staghorn calculi present a particular and challenging entity of stone morphology. Treatment is associated with lower stone-free rates and higher complication rates compared to non-staghorn stones. In this review we looked for the most relevant data on preoperative imaging and access planning to help decision making for percutaneous surgery with this complex condition.

Methods

We conducted a PubMed search of publications in the past 2 decades that include relevant information on the planning for management of staghorn stones. Non-contrast computerized tomography (NCCT) is indeed the standard imaging tool for percutaneous nephrolithotomy (PCNL); additional tools such as three-dimensional computed tomography (CT) reconstruction of the staghorn calculus may help plan access in complex cases. Ultrasound guided percutaneous access may be considered for staghorn stones when planning upper pole access in kidney malposition or complex intrarenal anatomy or with complex body habitus. Wideband doppler ultrasound and real-time virtual sonography can assist. New technologies to improve kidney access such as Uro Dyna-CT or electromagnetic sensor have been reported, but have not shown utilization in staghorn cases. Staghorn morphometry-based prediction algorithms may predict the number of tract(s) and stage(s) for PCNL monotherapy. Lower pole access can be equally effective as upper pole when planning for staghorn and complex stones, with significantly less complications rate; Stone-Tract length-Obstruction-Number of involved calyces-Essence of stone density (STONE) nephrolithometry seems to be the best system to predict outcomes of PCNL in staghorn cases. There is a growing trend of endoscopic combined intrarenal surgery (ECIRS) in concordance with PCNL to treat larger stones. Conservative management of staghorn calculi is an undesired option, but can be an alternative for a carefully selected group of high-risk patients.

Conclusion

Staghorn stones may lead to deterioration of renal function and life-threatening urosepsis. This entity should be managed aggressively with planning ahead for surgery using the different tools available as the cornerstone for a successful outcome.

Morphometry scores: Clinical implications in the management of staghorn calculi

Due to their large size, rapid growth, and attendant morbidity, staghorn calculi are complex clinical entities that impose significant treatment-related challenges. Moreover, their relative heterogeneity-in terms of both total stone burden and anatomic distribution-limits the ability to standardize their characterization and the reporting of surgical outcomes. Several morphometry systems currently exist to define the volumetric distribution of renal stones, in general, and to predict the outcomes of percutaneous nephrolithotomy; however, they fall short in their applicability to staghorn stones. In this review, we aim to discuss the clinical utility of morphometry systems and the influence of pelvicalyceal anatomy on the management of these complex calculi.

Impact of Anterior Kidney Calyx Involvement of Complex Stones on Outcomes for Patients Undergoing Percutaneous Nephrolithotomy

INTRODUCTION

A number of factors that can impact the outcomes of percutaneous nephrolithotomy (PCNL) procedures have previously been investigated. Complex stones that extend to the anterior calyx could affect the success and complication rates of PCNL.

OBJECTIVE

We analyzed the effect of anterior calyx involvement on the outcomes of patients with complex stones treated with PCNL.

METHODS

A total of 132 consecutive patients who underwent PCNL due to complex stones (multiple, partial staghorn, or staghorn stones) between 2015 and 2017 were enrolled in this study. They were stratified into two groups based on whether the stone extended to the anterior calyx (group 1, n = 45) or not (group 2, n = 87). The stratification was achieved through contrast-enhanced computerized tomography (CT). Demographics, laboratory tests, and peri- and postoperative findings (operation and fluoroscopy duration, hospital stay, utilization of flexible instruments, access numbers, total blood count change, stone-free rate [SFR], and complications) were compared between the groups. The SFR was evaluated by plain kidney-ureter-bladder radiography or CT.

RESULTS

The demographics, operation and fluoroscopy duration, access number, and hospital stay were similar between the groups (p < 0.05). A higher drop in the hemoglobin level in group 1 was identified (group 1 [2.14 ± 1.49 g/dL] vs. group 2 [1.43 ± 1.31 g/dL]) (p = 0.006). The SFR among the patients with extension to the anterior calyx was 60%, compared to 77% among the patients with no extension to the anterior calyx (p = 0.041). Flexible instruments were utilized in 60% of the patients of group 1, which was a higher rate than for group 2 (36%) (p = 0.007). Complication rates were similar in the two groups according to the Clavien-Dindo classification (p > 0.05).

CONCLUSIONS

Our study demonstrated that complicated stones with extension to the anterior calyx are more challenging than cases without extension to the anterior calyx. This was noted by a lower SFR, a more prominent drop in total blood count, and more frequent utilization of flexible scopes.

Robotic management of large stone disease: a case series

The gold standard for urologic management of large stone disease traditionally has been percutaneous nephrolithotomy (PCNL). An alternative to PCNL is robotic pyelolithotomy (RP), which continues to gain traction. This study is a retrospective review of ten cases performed over a 2 year period presenting operative outcomes for large stone disease treated with RP. The mean and standard deviation were calculated for age, body mass index, stone volume, stone diameter, pre-operative creatinine, operative time, robot-docked time, length of stay, post-operative creatinine, and estimated blood loss. In addition, results were collected for post-operative complications and secondary procedure requirements. Complete stone clearance was successful in 9 of 10 cases. The average renal function remained stable from a pre-operative creatinine of 0.917 mg/dL to a post-operative creatinine level of 0.943 mg/dL. This case series demonstrates that robotic assisted surgery has practical application when managing large stone disease.

Definition, treatment and outcome of residual fragments in staghorn stones

Technological advances in minimally invasive treatment of stone disease and its integration with concomitant clinical practice are amongst the most important achievements in urology. Despite the wealth of information accumulated over the years and the richness of existing literature, the knowledge about the definition, treatment and outcomes of residual stone fragments after percutaneous nephrolithotomy (PNL) is still insufficient. Due to the high stone load a lot of patients with staghorn stones have residual fragments (RFs) after treatment with PNL, which depends on the size of tract, definition of stone free rate (SFR), timing of evaluation and the imaging used. No consensus exists on the imaging modality or their timing in the evaluation of possible RFs. The treatment of residual stones is apparently different depending on the facilities of the department and the preference of the surgeon, which includes active surveillance, shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) or a second look PNL.

Simultaneous and synchronous bilateral endoscopic treatment of urolithiasis: a multicentric study

Introduction

The general prevalence of bilateral urolithiasis has risen to 15% and bilateral non-simultaneous treatment has been reported to have good outcomes. The objective of this study was to evaluate the effectiveness and safety of simultaneous bilateral endoscopic surgery (SBES).

Material and methods

An international multicenter analysis was performed between May 2015 and December 2017. All patients with bilateral stone disease that underwent SBES were included. Patients were treated under general anesthesia in either the supine or lithotomy position. Demographic, clinical, intraoperative and postoperative data were analyzed.

Results

A total of 47 patients were included. Mean age was 53.8 years and 70% of the patients were males. The mean American Society of Anesthesiology (ASA) score was 2. The mean diameter of right- and left-sided stones was 29.43 mm (2–83 mm) and 31.15 (4–102 mm), respectively. Staghorn stones were treated in 18 cases (8 right-sided and 10 left-sided), four of them were defined as complete staghorn. The procedures performed were 42 cases of bilateral URS and PCNL and ureteroscopy. Additionally, 5 bilateral flexible ureteroscopy (fURS) cases were described. Intraoperative complications occurred in five patients: four of them were classified as Clavien-Dindo (CD) I and one as CD II. Postoperatively, there were two cases with CD I, 6 with CD II and one CD IIIa.

The stone-free status was 70%. Residual stones (30%) were detected only on the side treated for high-volume (complete) staghorn calculi.

Conclusions

SBES is a feasible, effective and safe procedure. It may potentially avoid repeated anesthetic sessions as needed for staged procedures and reduce the length of patients' hospital stay.

Stone residual fragments: A thorny problem

Urolithiasis represents a widespread and common disorder among the world population, with a predicted increase in affected patients in the coming years. Treatment of renal and ureteral stones varies widely, and achieving true stone-free status in all patients is still difficult. Moreover, imaging used to assess residual fragments following procedure impacts the diagnosed stone-free rate percentage considerably. In particular, the use of computed tomography scans has led to a better evaluation of residual fragments as well as so-called clinically insignificant residual fragments, which in a considerable number of cases are, despite their definition, causes of adverse urological events, thus creating a thorny problem for both patients and urologists. Currently, there is no gold standard or validated protocol regarding the management, clearance and prevention of residual fragments. In this article, we review the current literature regarding residual fragments, clinically insignificant residual fragments and their natural history, reporting on diagnostic methods, incidence, complications and outcome with the use of less invasive procedures, taking into consideration viable treatment and management of patients affected.

Robotic pyelolithotomy for the treatment of large renal stones: a single-center experience

BACKGROUND

Few studies have reported robotic pyelolithotomy (RPL) series; furthermore, the most of all have reported small and single-center series. Herein we report our experience from 70 cases of complex kidney stones treated with RPL at our surgical center; this study reports the largest series of RPL in a minimal invasive experienced center.

METHODS

Between February 2016 and March 2018, 70 patients with complex renal stones (Guy's Stone Score: 4) underwent RPL and included in a prospectively maintained institutional database. Baseline characteristics, clinical data, perioperative data, postoperative data and stone free status were assessed by descriptive statistics.

RESULTS

Of 70 patients, 72.85% presented renal pelvis stones. The mean maximum stone diameter was 33.1±14.5 mm (median 30 mm; interquartile range 22-40 mm). Mean total operative duration was 122.5±34.4 min (median 120 min; interquartile range 105-135 min). In two patients (2.8%), a grade III complications were noted; no major complications (grade IV-V) were noted. The complete SFR, after a single robotic procedure, was 92.8%.

CONCLUSIONS

Our findings suggest that RPL is a safe, reproducible and minimally invasive approach as treatment of large renal stones when endoscopic treatment failed or was not available. RPL permits to achieve an excellent stone free status, in a single definitive procedure.

Supra-costal tubeless percutaneous nephrolithotomy is not associated with increased complication rate: a prospective study of safety and efficacy of supra-costal versus sub-costal access

Background

To assess the morbidities of tubeless percutaneous nephrolithotomy (PCNL) using supra-costal access and re-evaluate traditional concept of increased complications with supra-costal access.

Methods

From January 2010 to December 2014, a single surgeon performed 118 consecutive one-stage fluoroscopic guided PCNL’s for complex renal and upper ureteral stone. Our definition for complex renal stone is defined as partial or complete staghorn stone, multiple renal stones in more than 2 calyxes, obstructive uretero-pelvic stone > 2 cm, and a renal stone in single functional kidney. Inclusion criteria include: staghorn stones, renal calculi > 2 cm in diameter, upper ureteral stone > 1.5 cm in diameter. Exclusion criteria for tubeless PCNL include: significant bleeding or perforation of the collecting system, large residue stone, multiple PCNL tract and obstructive renal anatomy. Morbidity, operation time, analgesia requirement, length of hospital stay, stone- free rate, were analyzed.

Results

Of the 118 consecutive PCNL, eighty-six patients underwent tubeless PCNL (56 supra-costal and 30 sub-costal) and included in our prospective follow-up period. The mean age, operation side, stone locations were similar. The male to female ratio is higher in supra-costal than sub-costal. Large renal stones and staghorn stones makes up for most patients (supra-costal: 75%, sub-costal: 80%). The stone–free rate of supra-costal group was 59% (33/56) and in sub-costal group was 50% (15/30). The operative times, length of stay, post-op analgesic use, hematocrit change was similar in both groups. The overall complication rate is 6% [supra-costal (1/56), sub-costal (4/30)] with the majority being infectious complications.

Conclusions

Supra-costal access above 12th rib during tubeless PCNL is safe and effective procedure and is not associated with higher incidence of post-op complications in experience hands.

Shock Wave Lithotripsy is More Effective for Residual Fragments after Percutaneous Nephrolithotomy than for Primary Stones of the Same Size: A Matched Pair Cohort Study

Aims

To compare the outcome of shock wave lithotripsy (SWL) on post-percutaneous nephrolithotomy (PCNL) residual fragments (RFs) versus primary stones of the same size through a matched pair study.

Methods

Patients with a single 5-15 mm fragment 3 months after PCNL were enrolled (study group n = 59). The control group (n = 67) consisted of all adult patients with a single 5-15 mm renal stone.

Results

The success rate of SWL was significantly higher in the study group (81.4 vs. 59.7%; p = 0.008; OR: 2.95). With a cutoff point of Hounsfield units (HU) 750: the success rate was significantly lower in patients with a stone HU ≥ 750 (OR: 3.488). This HU cutoff value had no effect on the outcome of SWL in patients with post-PCNL RF (p = 0.14). On the other hand, the outcome of SWL was significantly more favorable in control group when HU < 750 (p = 0.02).

Conclusion

The success rate of SWL was 2.95-fold higher for post-PCNL RFs than in a stone burden-matched control group. The likelihood of stone clearance after SWL was 3.488-fold greater when HU was less than 750. This effect of HU was more prominent in patients receiving SWL for their primary stones while SWL was evenly effective on post PCNL RFs with different HUs.

Long-term effects of anatrophic nephrolithotomy on selective renal function

To evaluate the long-term changes of selective renal function after anatrophic nephrolithotomy (ANL). A retrospective study was conducted for patients who underwent ANL between January 1995 and December 2016. Inclusion criteria were availability of preoperative and follow-up (1 year or more) radio-isotopic renal scans. Stone-free status was evaluated after 1 month with KUB and ultrasonography or NCCT. Renal isotope scans using 99mTc MAG3 were performed to measure the changes in selective function of the affected kidney (GFR%). Eligible patients were classified into two groups, group 1 patients with stable or improved function and group 2 patients with deteriorated function (> 5% decrease in GFR%). Univariate and multivariate analyses were performed to determine risk factors for deterioration of renal function. The cutoff value for any significant variable was determined using ROC curve. The study included 50 patients with mean age 43.8 + 13.9 years. Complications developed in 26 patients (52%), and stone-free status was documented in 42 patients (84%). After a median follow-up of 2.7 years (range 1-11), mean GFR% of all cases significantly decreased from preoperative value of 52.7% + SD 20 to 45.4% + SD 25% during follow-up (P < 0.001). Deterioration of GFR% was documented in 21 kidneys (42%). Cold ischemia time with a cutoff value 50 min was the independent risk factor (RR 3.986, 95% CI 1.069-14.869, P 0.039). The results of this study support limiting ANL to a selected group of patients and taking all the possible efforts to minimize cold ischemia time below 50 min.

The outcome of percutaneous nephrolithotomy on ≥50 mm staghorn and multiple calyceal stones

Objective

To determine the success rate of percutaneous nephrolithotomy (PNL) in kidney stones over 50 milimeters.

Material and methods

Twenty-four patients with a renal stone size of >50 mm between January 2007 and December 2016 were enrolled. Stone-free and complication rates were investigated.

Results

Twenty-one (87.5%) patients were male and 3 (12.5%) were female. Fifteen (62.5%) stones were located in the right, and 9 (37.5%) in the left kidney. Twenty-one (87.5%) patients were operated using single-access, and three (12.5%) patients were double-access. Thirteen (54%) patients were found to have no stone after operation and 11 (46%) patients had residual stones. Extracorporal shock wave lithotripsy was applied to 5 of 11 patients with residual stones, while flexible ureteroscopy was applied to 6 of them. After additional treatments, 8 (33.5%) patients were observed to be stone free. The stone-free rate was 87.5%. The mean operation time was 135.43 (85-240) minutes. Hemoglobin levels before and after operation were 14.8 (12-16.7) and 12.6 (9.3-15.5), respectively (p=0.001). The hospital stay was 6.04 (4-8) days. Complications were observed in four patients (16.6%).

Conclusion

PNL has high stone-free rate on staghorn type large stones compared with multiple calyceal scattered large stones.

Lateral percutaneous nephrolithotomy: A safe and effective surgical approach

Introduction:

Percutaneous nephrolithotomy (PCNL) is traditionally performed with the patient in the prone position for large renal calculi. However, anesthetic limitations exist with the prone position. Similarly, the supine position is associated with poorer ergonomics due to the awkward downward position of the renal tract, a smaller window for percutaneous puncture, and a higher risk of anterior calyx puncture. This study aimed to demonstrate the feasibility and safety of lateral-PCNL in managing large renal calculi without the disadvantages of prone and supine positions.

Methods:

Retrospectively, 347 lateral-PCNL cases performed from July 2001 to July 2015 were examined. the patient's thorax, abdomen, and pelvis were positioned over a bridge perpendicular to a “broken” table, creating an extended lumbodorsal space. The procedure was evaluated in terms of stone clearance at 3 months’ postprocedure, operative time, and complications.

Results:

Primary stone clearance was achieved in 82.7% of patients. The mean operating time was 97 min. The average time taken to establish the tract and mean radiation time were 4.5 min and 6.93 min, respectively. In total, 2.3% of patients required postoperative transfusion, and 13.5% of patients had postoperative fever. There was one case of hydrothorax, but no bowel perforation.

Conclusions:

Our lateral-PCNL technique allows for effective stone clearance due to good stone ergonomics and it should be considered as a safe alternative even in the most routine procedures.

Single lower calyceal percutaneous tract combined with flexible nephroscopy: A valuable treatment paradigm for staghorn stones

INTRODUCTION

We evaluated the efficacy and safety of single lower calyceal tract combined with flexible nephroscopy for the management of staghorn renal stones by percutaneous nephrolithotomy.

METHODS

The medical records of patients who underwent percutaneous nephrolithotomy for the management of staghorn stones were analyzed. We included patients aged >18 years, while patients with incomplete data and renal anatomical anomalies were excluded from the study. Stone-free rate, postoperative complications, procedure duration, fluoroscopy time, and length of hospitalization were recorded. Postoperative outcomes were evaluated by non-contrast computed tomography scan 4-6 weeks after the operation. Stone-free status was defined as the absence of residual stones >4 mm.

RESULTS

The study cohort consisted of 103 consecutive patients. Stone-free rate was 65.0%. No complications were observed in 69.9% of the cases; most postoperative complications were Grade 1 (13.6%) and 2 (10.7%). Five patients (4.9%) suffered a Grade 3a complication and another patient (1.0%) suffered a Grade 3b complication.

CONCLUSIONS

Percutaneous nephrolithotomy through a single lower calyceal tract combined with flexible nephroscopy can be a valuable treatment option for the treatment of staghorn calculi, providing efficacy and safety. Nevertheless, the present study is limited by both its retrospective nature and being conducted at a single centre and, thus, proper prospective studies with head-on comparisons are needed to prove or disprove the advantages and disadvantages of either approach.

Laparoscopic and robotic surgery for stone disease

Treatment for stone disease has evolved drastically during the past 3-4 decades. Ureteroscopy, percutaneous nephrolithotomy along with SWL, provides the means to treat practically all urinary tract stones with minimal invasion to the patients. However, for complex stone case scenarios where open surgery is being considered, a less invasive and better tolerated option such as laparoscopy (robot assisted or not) can be performed. The present manuscript reviews role of laparoscopic and robotic surgery in treating urinary tract stones.