Research progress of percutaneous nephrolithotomy

Renal Access in Pediatric Supine Miniaturized Percutaneous Nephrolithotomy: Comparative Evaluation of Ultrasound-Fluoroscopy Combined and Biplanar (0°-90°) Fluoroscopic Techniques

Introduction: Ultrasound (US)-guided puncture has the benefits of avoiding radiation and limiting the risk of visceral injury. We aimed to evaluate the results of two different renal access techniques during pediatric supine mini percutaneous nephrolithotomy (smPCNL) in a comparative manner. Patients and Methods: Data obtained from pediatric patients undergoing smPCNL by single surgeon between September 2021 and 2023 were reviewed retrospectively. Children were divided into two groups namely; biplanar 0°-90° fluoroscopy (Group-F) and US-fluoroscopy combined (Group-C). In all cases, preoperative, operative, and postoperative findings were recorded. Success was defined as the determination of either no (complete stone-free status) or < 4 mm residual fragments (CIRF) on US and X-ray (postoperative 3rd month) images. Complications were evaluated according to modified Clavien-Dindo classification. Results: Data of 54 patients with a mean age of 8.6 years (Group-F = 30, Group-C = 24) are reviewed. In addition to the similar success rates in both groups (Group-F = 86.7% Group-C = 87.5% p = 0.928), similar minor complications were noted in the majority of the cases. No child required transfusion and/or angioembolization. Although the fluoroscopy and operation time were lower in Group-C, the difference was not statistically significant. Conclusion: US-fluoroscopy combined access technique can be applied with similar success and complication rates in pediatric smPCNL. Ultimately, as experience is gained, this technique may lower radiation exposure, although this was not observed in the current study.

Impact of frailty on perioperative outcomes following percutaneous nephrolithotomy in older persons: evidence from the US Nationwide Inpatient Sample

To evaluate the impact of frailty on perioperative outcomes of older patients undergoing PCNL, utilizing the US Nationwide Inpatient Sample (NIS) database. Data of hospitalized patients ≥ 60 years who received PCNL were extracted from the 2010 to 2020 NIS database, and included demographics, clinical, and hospital-related information. Patients were assigned to low (< 5), medium (5-15), and high frailty risk (> 15) groups based on the hospital frailty risk score (HFRS). Associations between frailty risk and perioperative outcomes including total hospital cost were determined using population-weighted linear and logistic regression analyses. Data of 30,829 hospitalized patients were analyzed (mean age 72.5 years; 55% male; 78% white). Multivariable analyses revealed that compared to low frailty risk, increased frailty risk was significantly associated with elevated in-hospital mortality (adjusted odds ratio (aOR) = 10.70, 95% confidence interval (CI): 6.38-18.62), higher incidence of unfavorable discharge (aOR = 5.09, 95% CI: 4.43-5.86), prolonged hospital length of stay (LOS; aOR = 7.67, 95% CI: 6.38-9.22), increased transfusion risk (aOR = 8.05, 95% CI: 6.55-9.90), increased total hospital costs (adjusted Beta = 37.61, 95% CI: 36.39-38.83), and greater risk of complications (aOR = 8.52, 95% CI: 7.69-9.45). Frailty is a significant prognostic indicator of adverse perioperative outcomes in older patients undergoing PCNL, underscoring importance of recognizing and managing frailty in older patients.

Simplified biplanar (0-90°) versus monoplanar renal puncture technique in flank free modified supine percutaneous nephrolithotomy regarding outcomes and learning curve: Randomized clinical trial

Objective

To evaluate the learning curve and the success rate of the biplanar (0-90°) puncture technique in the flank-free modified supine position in comparison to the monoplanar puncture technique.

Methods

Randomized controlled study included 68 patients more than 18 years with renal stones more than 2 cm from August 2021 to August 2022 were randomly classified by closed envelope method into group A (34 patients) scheduled for monoplanar renal puncture technique in flank-free modified supine PCN. Meanwhile, group B (34 patients) was scheduled for the 0-90° simplified fluoroscopic puncture technique. Morbid obese patients and patients with contraindications for PNL were omitted from the study.

Results

There was no significant difference between both groups regarding stone distribution and patients' demographic data. There was a significant difference between both groups regarding puncture attempts. In 88.2% of patients in group B (Biplanar group), the success of renal puncture occurred from the 1st puncture attempt while in 11.2% of patients in group A (monoplanar group). There was a statistically significant difference between both groups in fluoroscopy time and total operation time (p-value <0.001 & p-value: 0.001), respectively. The stone-free rate was 85.2% vs. 88.2% in both groups, respectively, without significant difference. In this study puncture, attempt trials and puncture time were used as indicators for the easiness and rapid educability of the biplanar (0-90°) fluoroscopic guided renal puncture technique. In the biplanar (0-90°) group after 24 cases, the learning curve had reached the plateau.

Conclusion

Biplanar (0-90°) puncture technique in flank-free modified supine position allows an easy puncture technique with an easy learning curve without affecting the success rate or complication rate.

Endoscopic dilation using two guidewires: a novel approach for establishing access tract during percutaneous nephrolithotomy under ultrasonographic guidance

OBJECTIVE

To evaluate the efficacy and safety of a novel endoscopic dilation (END) method during percutaneous nephrolithotomy under ultrasonographic guidance.

METHODS

We retrospectively reviewed the clinical records of 138 patients who underwent percutaneous nephrolithotomy from June 2020 to December 2021. The patients were divided into three groups based on the method of nephrostomy tract creation: those who underwent fascial Amplatz serial fascial dilation (AMD) (n = 45), one-shot dilation (OSD) (n = 45), and END (n = 48). For END, a 20-Fr dilator with sheath was accessed over the first guidewire. A second guidewire was inserted into the collecting system via the endoscope. The nephroscope was then accessed to enlarge the renal puncture point using both guidewires. Demographic variables and important intraoperative and postoperative findings were compared among the three groups.

RESULTS

The preoperative characteristics were similar among the three groups. The END group had a significantly shorter access time than both the AMD and OSD groups and significantly less severe hemoglobin loss than the OSD group. There were no significant differences in the other important perioperative findings.

CONCLUSION

Use of this novel END method with two guidewires may be associated with less blood loss and a reduced access time.

Chinese mini percutaneous nephrolithotomy for upper urinary calculi under local infiltration anesthesia

Percutaneous nephrolithotomy is generally performed under general or regional anesthesia; however, it is rarely performed under local infiltration anesthesia (LIA). This study aimed to assess the safety and effectiveness of Chinese mini percutaneous nephrolithotomy (MPCNL) for upper urinary calculi under LIA. A retrospective analysis of 52 patients with upper urinary stones who underwent MPCNL under LIA from April 2019 to May 2022 was performed. Pethidine and Phenergan were intramuscularly injected 30 minutes preoperatively. Oxybuprocaine hydrochloride gel was applied to the urethra for lubricating and mucosal anesthesia. Ropivacaine hydrochloride and lidocaine were injected into the whole percutaneous channel for local anesthesia. An 8/9.8F ureteroscope and an 18F vacuum-assisted access sheath were applied in MPCNL. All 52 patients tolerated procedures and underwent operations successfully; none of them converted the anesthesia method or required additional analgesia. The mean visual analogue scale scores intraoperatively and at 6 hours, 24 hours, and 48 hours after surgery were 3.25 ± 0.52, 3.13 ± 0.69, 2.25 ± 0.56, and 1.58 ± 0.50, respectively. The stone free rate was 84.6%. Complications were seen in 6 (11.5%) patients, including fever in 2 patients (Clavien I), renal colic in 1 patient (Clavien I), clinically insignificant bleeding in 2 patients (Clavien I), and urinary tract infection in 1 patient (Clavien II). No severe complications were observed in any patients. Chinese MPCNL under LIA was a feasible option and achieved good outcomes in appropriately selected patients, and it may become the routine procedure for general patients.

Super-stiff guidewire or loach guidewire during percutaneous nephrolithotomy?

Objectives

The objectives of this work are to compare the outcomes between loach guidewire and super-stiff guidewire during percutaneous nephrolithotomy (PCNL) and find potential indications of different guidewires.

Patients and methods

We retrospectively reviewed our institutional PCNL database from 2017 to 2021. Patients who underwent PCNL guided by loach guidewire were assigned to group A (489 patients); patients who received super-stiff guidewire were assigned to group B (269 patients). Preoperative demographic data, intraoperative parameters, and postoperative complications were compared. The conditions and reasons of failed placement of guidewire needed readjustment were evaluated as well.

Results

Preoperative demographic data and most intraoperative parameters were not statistically different between the groups. Postoperative Clavien-Dindo complications were also comparable, with low rate of complications. However, failed placement of guidewire more occurred in group A (8.2% vs. 4.0%, respectively, p = 0.03). Compared with the super-stiff guidewire, the loach guidewire was easier pass/slip into any place either it be perinephric or blood vessels. In most failed group A cases and all failed group B cases, the guidewire was placed in the perirenal fat. Six patients (15%) in group A, the guidewires entered into vessels.

Conclusions

Our results support that the faulty placement of loach guidewire is significantly more common compared with super-stiff guidewire. Double confirmation is needed to prevent a major complication out of wrong dilatation whenever there is doubt about the wrong location of the guidewire.

Analysis of pre-operative risk factors for post-operative urosepsis following mini-percutaneous nephrolithotomy in patients with large kidney stones

PURPOSE

To assess the pre-operative risk factors for post-operative urosepsis following mini-percutaneous nephrolithotomy (mPCNL) in patients with large kidney stones. Methods：Records of 171 patients with large (≥30mm) kidney stones who underwent mPCNL from December 2013 to October 2019 were reviewed. Demographic data of patients, pre-operative urine analysis, urine culture, routine blood tests and abdominal computerized cosmography data were collected and analyzed. A predictive nomogram model was established based on the results of logistic regression.

RESULTS

29 patients (17%) developed post-operative urosepsis in this study. Univariate analysis demonstrated that preoperative urine leukocytes (P <0.001), urine nitrite (P <0.001), stones in adjacent calices on the coronal plane (P <0.001), the maximum cross-sectional area of stones (P <0.001), the diameter of hydronephrosis (P =0.010) and number of stones (P=0.044) were associated with post-operative urosepsis after mPCNL in patients with large kidney stones. And pre-operative urine leukocytes ≥450/ µl (P=0.002) was the only independent risk factor for post-operative urosepsis in multivariate logistic regression analysis. Based on the results of multivariate regression, a nomogram model was established for the prediction of post-operative urosepsis with ideal discrimination (area under receiver operating characteristic curve was 0.867).

CONCLUSION

Patients with certain pre-operative characteristics, including higher urine leukocytes, positive urine nitrite, stones in adjacent calices on the coronal plane, larger maximum cross-sectional area of stones, larger diameter of hydronephrosis and larger number of stones, who received mPCNL may have a higher risk of postoperative urosepsis. A predictive model can help urologists identify patients who may develop post-operative urosepsis with high probability.

Predictive Model for Systemic Infection After Percutaneous Nephrolithotomy and Related Factors Analysis

Objectives: To investigate the factors associated with systemic infection after percutaneous nephrolithotomy (PCNL) and establish a predictive model to provide theoretical basis for the prevention of systemic inflammatory response syndrome (SIRS) and urosepsis correlate to percutaneous nephrostomy.

Methods: Patients received PCNL between January 2016 and December 2020 were retrospectively enrolled. All patients were categorized into groups according to postoperative SIRS and urosepsis status. Single factor analysis and multivariate logistic regression analysis were performed to determine the predictive factors of SIRS and urosepsis after PCNL. The nomograms were generated using the predictors respectively and the discriminative ability of was assessed by analyses of receiver operating characteristic curves (ROC curves).

Results: A total of 758 PCNL patients were enrolled in this study, including 97 (12.8%) patients with SIRS and 42 (5.5%) patients with urosepsis. Multivariate logistic regression analysis suggested that there were 5 factors related to SIRS, followed by preoperative neutrophil to lymphocyte ratio (NLR) (odds ratio, OR = 1.721, 95% confidence interval, CI [1.116–2.653], p = 0.014), S.T.O.N.E. score (OR = 1.902, 95% CI [1.473–2.457], p < 0.001), female gender (OR = 2.545, 95% CI [1.563–4.144], p < 0.001), diabetes history (OR = 1.987, 95% CI [1.051–3.755], p = 0.035), positive urine culture (OR = 3.184, 95% CI [1.697–5.974], p < 0.001). And there were four factors related to urosepsis, followed by preoperative NLR (OR = 1.604, 95% CI [1.135–2.266], p = 0.007), S.T.O.N.E. score (OR = 1.455, 95% CI [1.064–1.988], p = 0.019), female gender (OR = 2.08, 95% CI [1.063–4.07], p = 0.032), positive urine culture (OR = 2.827, 95% CI [1.266–6.313], p = 0.011). A nomogram prediction model was established to calculate the cumulative probability of SIRS and urosepsis after PCNL and displayed favorable fitting by Hosmer–Lemeshow test (p = 0.953, p = 0.872). The area under the ROC curve was 0.784 (SIRS) and 0.772 (urosepsis) respectively.

Conclusion: Higher preoperative NLR, higher S.T.O.N.E. score, female gender, and positive urine culture are the most significant predictors of SIRS and urosepsis. Diabetes history is the predictor of SIRS. These data will help identify high-risk individuals and facilitate early detection of SIRS and urosepsis post-PCNL.

The retrospective study of perioperative application of dexamethasone and furosemide for postoperative anti-inflammation in patients undergoing percutaneous nephrolithotomy

Objectives

To investigate whether the perioperatively combined application of dexamethasone and furosemide could alleviate the inflammation in patients undergoing percutaneous nephrolithotomy (PCNL).

Patients and methods

147 patients undergoing PCNL between November 2018 and October 2019 were enrolled in the study. 77 patients accepted a single dose of dexamethasone and furosemide administration (EXP group, n = 77), and 70 patients did not (CON group, n = 70). Demographic and perioperative data, inflammatory markers including interleukin-6 (IL-6) and procalcitonin (PCT), and clinical outcomes were compared between the two groups.

Results

Compared with the CON group, the incidence rate of urosepsis of the EXP group were significantly lower (11.69% vs. 24.29%, p = 0.046). 3 patients developed severe urosepsis in the EXP group, while 5 patients developed severe urosepsis in the CON group. Compared with those in the CON group, the patients with postoperative urosepsis in the EXP group showed lower serum levels of IL-6 at postoperative hour two (p = 0.045) and at postoperative day one (p = 0.031) and lower serum levels of PCT at postoperative day one (p = 0.015). There was a better clinical outcome of a shorter postoperative hospital stay (p = 0.015) in patients with postoperative urosepsis in the EXP group than in those in the CON group.

Conclusion

The perioperatively combined application of dexamethasone and furosemide was beneficial for alleviating postoperative inflammatory reaction and caused a better clinical outcome of a shorter postoperative hospital stay.