Classification of percutaneous nephrolithotomy complications using the modified clavien grading system: looking for a standard

Comparison of standard percutaneous nephrolithotomy and total tubeless percutaneous nephrolithotomy in the supine position

PURPOSE

To compare the efficacy, safety and advantages of the total tubeless (TT) percutaneous nephrolithotomy (PCNL) and standard PCNL in the supine position.

METHODS

This study was carried out at İzmir Tepecik Health Application and Research Center. A total of 87 patients were examined. Forty-three patients who underwent TT procedure were defined as Group 1, and 44 patients who underwent standard procedure with a nephrostomy tube were defined as Group 2. Two techniques were evaluated with demographic data and outcome parameters. Univariate regression analyses were performed in these data sets for the parameters that predicted the TT procedure.

RESULTS

The demographic data of the groups and all characteristics of the stones were similar. When the results were examined, the stone-free rates detected by non-contrast computed tomography (CT) in the postoperative 1st month were similar between the groups. Complication rates and secondary intervention rates were similar. Operation and fluoroscopy times were shorter in group 1, which were not statistically significant. Postoperative hemoglobin decreased, and creatinine values were similar. In Group 1, mean postoperative visual analog scale (VAS) scores and the percentage of VAS reporting > 5 points for pain level measurement were lower and statistically significant. In the univariate analysis of the factors predicting the TT procedure, no significant results were found in any parameter.

CONCLUSION

Performing TT PCNL in the supine position in selected patients reduces postoperative pain without affecting the complication rates as in prone PCNL. Our study is the first to compare TT and standard PCNL in supine position.

Is percutaneous nephrolithotomy effective and safe in infants younger than 2 Years old? Comparison of mini standard percutaneous nephrolithotomy

BACKGROUND

In this study, we aimed to compare the operative outcomes, postoperative outcomes, stone-free status and complications of SPCNL and MPCNL in infants younger than two years of age.

METHODS

We retrospectively analyzed 163 patients younger than two years of age who underwent percutaneous nephrolithotomy (PCNL) in our institution between September 1999 and March 2022. The patients were divided into two groups depending on the tract size. The MPCNL group consisted of 73 patients with a tract of 22 Fr or less, and the SPCNL consisted of 90 patients with a tract greater than 22 Fr.

RESULTS

The median age of 163 patients included in the study was 17.3 (range 7-24) months. Although the median stone size was lower in the SPCNL group, no statistically significant difference was found between the two groups in terms of stone size (p = 0.073). The median operative time was 74.8 min in the MPCNL group and 62.8 min in the SPCNL group, with a statistically significant difference (p = 0.002). Stone free rates (SFR) were 89 % and 90.8 % in the MPCNL and SPCNL groups, and the clinically insignificant residual fragments (CIRF) rates were 11 % and 4.6 %, respectively (p = 0.064). The fluoroscopy time, nephrostomy withdrawal time, and hospitalization stay were similar in the two PCNL groups (p = 0.535, p = 0.253, and p = 0.143, respectively). Postoperative fever was similar in MPCNL and SPCNL groups (p = 0.504). Although bleeding (6.7%-2.7 %) and blood transfusion (3.3%-1.4 %) rates were higher in the SPCNL group, there was no statistically significant difference (p = 0.248 and p = 0.420, respectively). Prolonged urinary leakage occurred in 6 (8.2 %) patients in the MPCNL group and 1 (1.1 %) patient in the SPCNL group, with a statistically significant difference (p = 0.026).

CONCLUSIONS

With the development of MPCNL, the use of SPCNL in infants has decreased considerably. However, SPCNL continues to be an effective and reliable method when needed in suitable patients. Although PCNL in infants shows some differences from adults, it is an effective and safe method for suitable patients.

LEVEL OF EVIDENCE

Although we created our study by retrospectively examining the pediatric urology data that we created prospectively, our study is of a retrospective nature. Therefore the Level of Evidence is 3.

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.

The safety and efficacy of Sotn ureteroscopy for renal and upper ureteral calculi: a prospective multicenter randomized controlled trial

BACKGROUND

Sotn ureteroscopy is a new lithotripsy procedure developed on the basis of ureteroscopy and includes a rigid ureteral access sheath, standard mirror, lithotripsy mirror, and Sotn perfusion aspirator. Thus, we performed a prospective multicenter randomized controlled trial comparing the safety and efficacy of Sotn ureteroscopy in the treatment of renal and upper ureteral calculi.

METHODS

In this study, 224 patients with renal and upper ureteral calculi were randomly divided equally into study and control groups from March 2018 to March 2022. All the patients were approved by the hospital ethics committee (proof number: ZF-2018-164-01 and ZF-2018-165-01) of the Second Affiliate Hospital of Guangzhou University of Chinese Medicine in China. The primary outcome was stone-free rate (SFR) assessed by computed tomography on the 1st day and month after treatment and operation duration. The secondary outcome was postoperative complication rate.

RESULTS

In total, for upper ureteral calculi, the SFR of 1 day after operation of the Sotn ureteroscopy group was significantly higher than the rigid ureteroscopy group (83.6% vs. 60%, P=0.006). Moreover, operative time (33.7±1.80 vs. 52.9±2.73 min, P<0.005) of the Sotn ureteroscopy group was significantly lower than the rigid ureteroscopy group. Additionally, the SFR of 1 day after operation and operative time for the study group (Sotn ureteroscopy combined with flexible ureteroscopy) and the control group (flexible ureteroscopy alone) were 63.2% and 36.8% (P=0.005), 65.6±4.06 and 80.3±4.91 (P=0.023), respectively. However, there were no significant differences in the SFR of 1 month after operation, success rate of ureteral access sheath placement, and postoperative complications between the two groups (P>0.05). In subgroups with stone diameters ≥1.5 cm and stone CT values ≥1000 Hounsfield units, Sotn ureteroscopy showed more advantages in terms of the SFR of 1 day after operation. Importantly, complications such as ureteral injury, sepsis, fever, and severe hematuria were not statistically different between the two groups (P>0.05).

CONCLUSIONS

For renal and upper ureteral calculi, Sotn ureteroscopy has the advantage of a higher SFR of 1 day after the operation and a shorter operative time, suggesting that the Sotn ureteroscopy may have further potential applications in clinics.

Comparison of RLP and PCNL for large pelvis calculi with CKD

OBJECTIVES

To compare the effect and safety of retroperitoneal laparoscopic pyelolithotomy (RLP) and percutaneous nephrolithotomy (PCNL) for large pelvis calculi with chronic kidney disease (CKD).

MATERIAL AND METHODS

Between June 2017 and July 2021, 62 patients with CKD and large renal pelvis calculi (>4 cm2) were treated with RLP. Another 62 patients receiving PCNL served as controls. The perioperative parameters were compared. All patients were followed up for at least 6 months with the stone-free rate and the recovery of renal function evaluated.

RESULTS

Significantly longer operation time (101.47 ± 9.25 vs 62.55 ± 7.54 min), less drop in hemoglobin level (0.90 ± 0.38 vs 2.13 ± 0.80 g/dl), staged operations (0% vs 12.9%), postoperative fever (3.23% vs 16.13%) and delayed bowel movement (3.23% vs 14.52), and shorter hospitalization time (3.90 ± 1.66 vs 4.72 ± 1.80 days) were observed in the RLP group (p < 0.05). The stone-free rates were 100% in the RLP group and 88.7% in the PCNL group at the 3-months follow-up (p < 0.05). The serum creatinine level was significantly lower in the RLP group at 24 h (2.81 ± 1.18 vs 3.00 ± 1.15 mg/dl) and 1 week (2.08 ± 1.13 vs 2.34 ± 1.01 mg/dl) postoperatively (p < 0.05).

CONCLUSIONS

Although associated with a longer operation time, RLP is a safer and more efficient surgical option for CKD patients with large pelvic stones than PCNL.

Feasibility of Simultaneous Bilateral Endoscopic Surgery in Prone Split-Leg Position for Bilateral Upper Urinary Tract Calculi: A Pilot Study

INTRODUCTION

We explored the viability of simultaneous bilateral endoscopic surgery (SBES) in the prone split-leg position for managing bilateral calculi.

METHODS

We retrospectively reviewed 72 patients who underwent SBES, with procedures involving ureteroscopy (URS) and contralateral percutaneous nephrolithotomy (PNL) simultaneously, in prone split-leg position.

RESULTS

Operative times averaged 109.38 ± 30.76 min, with an average hospital stay of 7.79 ± 3.78 days. The bilateral stone-free rate (SFR) was 70.83%, while URS and PNL demonstrated comparable unilateral SFR (83.33% and 79.17%, respectively). Receiver operating characteristics curves for predicting unilateral residual fragments yielded an area under the curve of 0.84 (URS) and 0.81 (PNL) with respective cutoff values of stone diameter of 11.55 mm and 23.52 mm. Fifty-seven (79.17%) and 15 (20.83%) patients encountered grade 0-1/2 complications, with no severe complications (grade 3-5) recorded. No significant changes in blood count or renal function were observed post-SBES.

CONCLUSIONS

SBES in the prone split-leg position is a viable option for managing bilateral upper tract urolithiasis. Larger scale studies are needed to further assess safety and efficacy in various positions.

A Comparative Analysis between Flexible Ureteroscopic Lithotripsy and Tubeless Percutaneous Nephrolithotomy in the Treatment of >15 mm Non-Obstructing Proximal Ureteral Stones

BACKGROUND

The proper surgical modality for large non-obstructing proximal ureteral stones is disputed. We compare effectiveness and safety of flexible ureteroscopic lithotripsy (FURL) and tubeless percutaneous nephrolithotomy (TPNL) in treatment of upper ureteral stones larger than 1.5 cm.

METHODS

We reviewed the medical records of patients who performed FURL or TPNL for upper ureteral stones between June 2016 and November 2018. Comparative analysis was conducted regarding demographic parameters, stone free rate, postoperative pain and complications.

RESULTS

This study included 58 patients treated with FURL and 60 patients treated with TPNL owing to upper ureteral stones larger than 1.5 cm. Stone size was similar in the FURL and TPNL groups (17.6 ± 2.6 vs. 18.0 ± 2.1 mm, p = 0.194). The overall 3-month stone clearance rate was 95.8% for FURL versus 96.0% for TPNL (p = 0.575). There was no difference between the FURL and TPNL groups for hospital stay (p = 0.280) and postoperative complications. On the other hand, patients treated with FURL had longer operative time (p = 0.012) and less postoperative pain (p = 0.008).

CONCLUSIONS

Both surgical techniques were considered feasible and effective surgical procedures in the treatment of large upper ureteral stones.

Clinical Utility of S.T.O.N.E, Guy's Scoring System, and Renal Stone Complexity Scoring in Predicting Outcome of Single-Tract Percutaneous Nephrolithotomy

BACKGROUND

Several imaging-based scores have been developed to predict postoperative stone-free state (SFS) and complications. This study aimed to assess the accuracy of the S.T.O.N.E., Guy Scoring System (GSS), and Seoul National University Renal Stone Complexity (S-ReSCS) scores in predicting the outcomes of single-tract percutaneous nephrolithotomy (ST-PCNL). This scoring system holds paramount importance for low-income and low-middle-income countries (LMICs), as it is inexpensive and cost-effective for the healthcare system.

METHODOLOGY

This retrospective study was carried out with 147 participants. Based on the preoperative computerized tomographic (CT) scan, each patient's S.T.O.N.E. score, GSS, and S-ReSCS were recorded. The modified Clavien grading system was used to document intra- and postoperative complications.

RESULTS

The mean age of the sample population was 45 years. SFS was achieved in 110 (74.8%) patients. The number of calyces involved (p = 0.008), S.T.O.N.E. scoring (p = 0.001), GSS (p = 0.008), and S-ReSCS (0.001) correlated well with the SFS. Forty-nine (33.33%) patients developed complications. The most common complications fell within Clavien grade II. No statistical significance was noted between the S.T.O.N.E. score, GSS, and S-ReSCS with the modified Clavien grading system.

CONCLUSION

The S.T.O.N.E. scoring, GSS, and S-ReSCS have a high predictive value for achieving SFS in ST-PCNL. In addition, findings from LMICs are comparable with those from the rest of the world.

What is the safe and effective dilator number during access in PCNL? Three-shot dilation versus classical sequential Amplatz dilation

BACKGROUND

Although PCNL has been used for a long time to treat nephrolithiasis, there is still contradictory information concerning the use of the dilation method. In this study, we aimed to compare conventional sequential Amplatz dilatation (SAD) using ten dilators and a method using three dilators (12, 20, and 30 Fr), which we named "three-shot dilatation" (3SD), in terms of fluoroscopy time (FT), operation time, bleeding and stone-free rates.

METHODS

The study included patients who underwent PCNL with the SAD and 3SD methods. A different surgeon with extensive endourology experience applied each technique. One of the surgeons operated on the patients using the SAD method with ten dilators, and the other surgeon performed the operations using the 3SD method involving three Amplatz dilators (12, 20, and 30 Fr).

RESULTS

A total of 283 patients, 138 in the 3SD group and 145 in the SAD group, were included in the study. The mean age of the patients was 47.32 ± 13.71 years. There was no statistically significant difference between the two groups regarding preoperative characteristics (p > 0.05). The FTs of access 2, total access, and total operation were significantly shorter in the 3SD group (p = 0.0001). The decrease in hemoglobin was statistically significant in the 3SD group compared to the SAD group (p = 0.022), while the blood transfusion requirements of the groups were similar (p = 0.176). There was no statistically significant difference between the two groups regarding stone-free rates (p = 0.973). In four patients in the SAD group, re-access was necessary due to the loss of passage due to the guide wire slipping out of its place.

CONCLUSION

Intraoperative FT can be shortened using the described 3SD method without compromising surgical safety. However, this method can be used as an intermediate step in the transition to one-shot dilation by surgeons experienced in performing SAD.

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.

Supine mini percutaneous nephrolithotomy in horseshoe kidney

OBJECTIVE

The percutaneous nephrolithotomy (PCNL) in Horseshoe kidneys (HSK) is usually performed in the prone position, allowing entry through the upper pole and providing good access to the collecting system. However, in patients with normal kidney anatomy, the supine position is reliable and safe in most cases, but it is unknown whether the supine position is adequate in patients with HSK. The purpose of this study was to describe the results of PCNL in HSK in three different surgical institutions and to evaluate the impact of supine position during surgery, comparing pre-operative and post-operative data, complications, and stone status after surgery.

MATERIAL AND METHODS

Between 2017 and 2022, a total of 10 patients underwent percutaneous renal surgery for stone disease in HSK. All patients were evaluated pre- and post- operatively with non-contrast CT. we evaluated patients (age and gender), stones characteristics (size, number, side, site and density ), and outcomes. The change in haemoglobin, hematocrit, creatinine and eGFr were assessed between the most recent preoperative period and the first postoperative day. Procedure success was defined as stone-free or presence of ≤4 mm fragments (Clinically Insignificant residual Fragments - CIrF). Complications were registered and classified according to Clavien-dindo Grading System, during the 30 - day postoperative period and Clavien scores ≥ 3 were considered as major complications. Statistical analysis was performed using "r 4.2.1" software, with a 5% significance level. we also compared pre-operative and post-operative data using "wilcoxon signedrank test".

RESULTS

No statistical difference was observed between preoperative and post-operative renal function data. At one post operative day CT scan, an overall success rate of 100% was registered. 9/10 patients were completely free from urolithiasis (stone-free rate: 90%), while 1/10 patients had ≤4 mm residual stone fragments (CIrF rate: 10%). No cases of intraoperative complications were registered. Post-operative complications were reported in 1/10 patients. A patient developed urosepsis (defined as SIrS with clinical signs of bacterial infections involving urogenital organs - Clavien-dindo Grade II) after procedure, and was treated with intravenous antibiotic therapy successfully.  Conclusions: This study shows that in patients with HSK mini- PCNL in supine position allows to achieve good stone free rate with a very low morbidity. According to our series, the described technique for PCNL in HSK should be an option. Nevertheless these results must be confirmed by further studies.

Safety and efficacy of percutaneous nephrolithotripsy in comorbid patients: A 3 years prospective observational study

PURPOSE

To report the result of percutaneous nephrolithotripsy (PCNL) via standard nephrostomy tract in a single training institution. The perioperative complications in relation to the comorbid state are particularly assessed.

PATIENTS AND METHODS

A prospective interventional study between January 2019 to November 2022, included 210 patients scheduled for PCNL. The average age was 40.3 ± 11.8 years (range 18- 67 years). Patients were categorized into two groups. The first group comprised 146 cases (69 .5%) with no associated co-morbidities while the second group 64 (30.5%) had co-morbidities such as obesity in 4 cases (1.9%), hypertension (HTN) in 24 cases (11.4%) cases, diabetes mellitus (DM) in 17 (8.1%) cases, history of recurrent stone surgery in 11 (5.2%) cases and more than one in 8 cases (3.8%). Co-morbidities, stone burden, location of stone, time of surgery, stay in the hospital, further operations, and negative events were among the reported data. Complications and the stone-free rate were the main outcome indicators.

RESULTS

Intraoperative complications were reported in 40 (18.8%) patients (18 group 1 and 22 group 2) during PCNL. Bleeding occurred in 22 (10.5%) patients (9 group 1 and 13 group 2), blood transfusions were needed in 4 (1.9%) (2 group 1 and 2 group 2), extravasation was observed in 11 patients (5.2%) (6 group 1 and 5 group 2) and cardiac arrhythmia in 3 (1.4%) (1 group 1 and 2 group 2) patients. Postoperative complications occurred in 61 patients (29%) (24 group 1 and 37 group 2) in the form of fever in 10 patients (4.8 %) (3 group 1 and 7 group 2) and prolonged leakage in 50 patients (23.8%) (21 group 1 and 29 group 2). One patient of group 2 died from postoperative sepsis. Extravasation and postoperative leakage were higher in diabetic patients than in non-diabetics. Stonefree rate was 60.5% (127 of 210). Clinically significant residual fragments (CSRFs) found in 70 cases (33.3%) (33 group 1 and 37 group 2). In 13 cases (6.2%) (5 group 1 and 8 group 2), clinically insignificant residual fragments (CIRFs) were found. In 8 (3 group 1 and 5 group 2) of the 13 cases, spontaneous stone passage was observed within 4-6 weeks of surgery. Residual stones in three cases (1 group 1 and 2 group 2) were asymptomatic and 4 mm or less, whereas stones increased in two cases of group 2. Among all factors studied, stone burden was significantly correlated to both intraoperative and postoperative complications. The occurrence of postoperative fever increased with large stone burden.

CONCLUSIONS

PCNL is a therapeutic modality that is effective, feasible, and safe for a wide range of patients with concurrent medical issues. A steep curve is required to reduce intraoperative and postoperative complications.

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.

Successful Management of an Inadvertent Placement of a Nephrostomy Tube Into the Inferior Vena Cava Following Percutaneous Nephrolithotomy: A Case Discussion and Literature Review of a Rare Complication

In a percutaneous nephrolithotomy (PCNL) procedure, the placement of the nephrostomy tube is usually inserted last to monitor and maintain urine drainage, avoid potential urine extravasation, and ensure hemostasis. In this report, we provide a clinical case involving the misplacement of a nephrostomy tube, resulting in direct perforation of the inferior vena cava (IVC) after undergoing one-sided PCNL that was successfully treated conservatively, and investigate the current management censuses from the literature for intravenous misplacement of a nephrostomy tube. In our patient, the tip of the nephrostomy catheter was located in the IVC. It was successfully managed using a one-step catheter withdrawal with the surgical vascular team on standby for any potential encounters with massive uncontrollable bleeding. An enhanced CT angiogram on day 14 post-PCNL revealed a lower polar renal arteriovenous pseudoaneurysm which required our patient to undergo selective angioembolization, resulting in maximal parenchymal preservation. The patient was successfully managed and discharged uneventfully. Thirteen cases that have reported inadvertent misplacements in the PubMed database have been discussed in this review. Our case would be the first documented report where a percutaneous nephrostomy drainage tube pierced through the IVC directly. Our case provides an argument for patients to be managed by tube withdrawal under one-step fluoroscopic guidance. Intensive care measures and ultrasound monitoring for two hours followed by another CT angiogram proved effective successful conservative management in a high-volume urologic practice.

Comparison of safety and efficacy of one shot dilation vs. gradual dilation technique in supine percutaneous nephrolithotomy

PURPOSE

To compare the efficacy and safety of gradual dilation (GD) and one-shot dilation (OSD) techniques in patients who underwent supine percutaneous nephrolithotomy (PCNL).

METHODS

The data of 176 patients who underwent supine PCNL were reviewed. Eighty-seven patients who underwent OSD were defined as group 1, and 89 patients who underwent GD were defined as group 2. Both surgical techniques were compared with each other in terms of various parameters. Then, regression analysis of factors predicting stone-free status and complications in patients who underwent supine PNL were performed. Then, regression analysis of factors predicting success rate and complications in patients who underwent supine PNL were performed.

RESULTS

No statistical difference was found in terms of stone-free rate, Clavien-Dindo complication grade and operation time. No statistical difference was found in terms of success rate, Clavien-Dindo complication grade and operation time. However, the fluoroscopy time was found to be significantly shorter in group 1 (p < 0.001). In the analysis of factors predicting stone-free status, the presence of calyceal stones, increased stone size and number were associated with a decrease in stone-free rate. In the analysis of factors predicting success, the presence of calyceal stones, increased stone size and number were associated with a decrease in success rate. Increased fluoroscopy and operation time, increased complication rates were found to be significantly associated with residual stone. Analysis of factors predicting complications found a higher complication rate in patients with low BMI and severe hydronephrosis. Increased complication was associated with increased time to nephrostomy removal and hospital stay, decrease in stone-free rate, decrease in Hb and increase in Cre value at the postoperative 24th hour.

CONCLUSION

When comparing OSD and GD in patients undergoing supine PCNL, both techniques have similar stone-free and complication rates. When comparing OSD and GD in patients undergoing supine PCNL, both techniques have similar success and complication rates. Compared to GD, the OSD technique can be preferred primarily due to its shorter fluoroscopy time.

A modified triangular Double-J stent for retrograde intrarenal surgery improvement of free-stone rate, and quality of life: a randomized controlled, multiple centers, perspective trial

PURPOSE

The goal of this study is to evaluate the efficacy and safety of modified triangular double-J (DJ) stent in 1-2 cm renal or ureter calculi after retrograde intrarenal surgery (RIRS) via a randomized, controlled clinical study.

METHODS

A total of 196 patients with 1-2 cm renal or ureter calculi who were performed RIRS and received 7Fr modified triangular DJ stents (100 cases) or 6Fr normal DJ stents (96 cases). All operations were performed by experienced surgeons. The clinical characteristics and outcomes were analyzed.

RESULTS

There were no significant differences between two groups in terms of age, gender, BMI, location, hydronephrosis, urea WBC, urea RBC, BUN, Cr, laser emission time, operation time, Hb loss, postoperative BUN, postoperative Cr. Patients who received modified triangular DJ stents were shown to have higher stone-free rate (p = 0.038), but lower general health (p = 0.004).

CONCLUSION

The modified triangular 7Fr DJ stents were more efficient for patients underwent RIRS than 6Fr normal DJ stents.

Hydrostatic pressure of the renal pelvis as a radiation-free alternative to fluoroscopic nephrostogram following percutaneous nephrolithotomy

Background

We evaluated the hydrostatic pressure of the renal pelvis (RPP) as a radiation-free alternative to fluoroscopic nephrostogram to assess ureteral patency after percutaneous nephrolithotomy (PCNL).

Methods

Retrospective non-inferiority study analyzing 248 PCNL-patients (86 female (35%) and 162 males (65%)) between 2007 and 2015. Postoperatively, RPP was measured using a central venous pressure manometer in cmH2O. The primary endpoint was to assess RPP depending on the patency of the ureter and the nephrostomy tube removal. Secondary, the upper limit of normal RPP of $$\le$$ ≤ 20 cmH2O was assessed as an indicator of an unobstructed patency.

Results

The median procedure duration was 141 min (112–171.5) with a stone free rate of 82% (n = 202). RPP was significantly higher in patients with obstructive nephrostogram with 25.0 mmH2O (21.0–32.0) versus 20.0 mmH2O (16.0–24.0; p < 0.001). The pressure was lower in successful nephrostomy removal with 18 cmH2O (15–21) versus 23 cmH2O (20–29) in the leakage group (p < 0.001). The analysis of a cut-off of $$\le$$ ≤ 20 cmH2O showed a sensitivity of 76.9% (95% CI [60.7%; 88.9%]) and a specificity of 61.5% (95% CI [54.6%; 68.2%]). The negative predictive value was 93.4% (95% CI: [87.9%; 97.0%]) and the positive predictive value 27.3% (95% CI [19.2%; 36.6%]). The accuracy of the model showed an AUC = 0.795 (95% CI [0.668; 0.862]).

Conclusion

The hydrostatic RPP seems to allow a bedside evaluation of ureteral patency after PCNL.

Mini-Perc for Renal Stones—A Single Center Experience and Literature Review

Aim: The aim of this study was to analyze the outcomes of miniaturized nephrolithotomy (mini-perc) in the management of renal stones with a diameter smaller than 20 mm. Materials and Methods: We retrospectively reviewed the records of 102 patients who underwent mini-perc between March 2015 and March 2020 in our department. The primary objective was the stone-free rate, but we also analyzed the retreatment rate, complications, hospital stay, operative time and reduction in hemoglobin level. All these patients had this technique as their first-line treatment, in a prone position, using a 16 Fr sheath size. Data were compared to a series of patients from the literature, treated with conventional PCNL. Results: The patients had calculus limited to either a single calyx or just extending to the renal pelvis, and stone size was less than 20 mm in its maximal dimension. The intrarenal stone location was in the upper calyx in 7 cases, middle calyx in 20 cases and lower calyx in 46 cases, and there were 29 patients with renal pelvis stone. The male to female ratio was 1.5:1, and the median age was 48.4 years. The average stone size was 17.4 mm in diameter (ranging between 9 and 20 mm) and all cases underwent Ho-YaG laser lithotripsy, ballistic energy and combined ultrasonic and ballistic lithotripsy. At the end of the procedure, an antegrade double J stent was placed under fluoroscopy for a maximum of 2 weeks in 42 cases, while 9 cases needed a nephrostomy tube 12–14 F. A total of 51 cases were totally tubeless. Our median operative time was 61 min (ranging from 35 to 75 min). The median hospitalization stay was 3.8 days. The stone free rate was 90.1% after one procedure, only nine (8.8%) cases needed a “second look” flexible ureteroscopy, and the final stone-free rate was 98% (absence of detectable calculi on ultrasound, KUB or non-contrast CT scan). The overall complication rate was 6.86% (Clavien classification I—57.14%; II—28.5%; III—14.2%), while no Clavien IV or V complications were reported. No patient required a blood transfusion, and mean hemoglobin loss was 0.81 mg/dL. Overall, our results are better than similar data for conventional PCNL in the literature. Conclusions: The “mini-perc” technique is an effective procedure for the treatment of the renal lithiasis that is less or equal to 2 cm. The results demonstrated that this minimally invasive technique is associated with a higher stone-free rate and minimal complications.

Ambulatory Minimally Invasive Endoscopic Combined Intrarenal Surgery in Management of Large Impacted Proximal Ureteral Calculi: A Feasibility Study at a Tertiary Referral Center

Aim: To conduct a comparative, nonrandomized study to assess the feasibility of mini-Endoscopic Combined Intrarenal Surgery (ECIRS) using supine Mini-percutaneous nephrolithotomy (PCNL) access (16F) in Galdakao-Modified Supine Valdivia position for managing proximal large-volume impacted ureteral calculi as ambulatory day-care surgery vis-a-vis standalone ureteroscopy (URS) with push-back PCNL, if needed. The primary aim was to study the outcomes and stone-free rates (SFRs). Secondary aim was to compare the intraoperative and short-term postoperative complications. Materials and Methods: Data of 60 patients undergoing ECIRS (Group 1) from January 2016 to December 2019 were collected prospectively in a nonrandomized fashion from a single center after Ethics Committee approval. A matched-paired analysis was performed with retrospectively collated data of 60 patients undergoing standard URS/pushback PCNL (Group 2) using analysis of variance, Fisher's exact test, and Chi-square test. p < 0.05 was considered statistically significant. Outcomes and Results: Group 1 patients had a significantly shorter procedure time vs Group 2 (42.1 ± 11.2 minutes vs 52.1 ± 13.7 minutes; p < 0.001). Group 1 (59/60) patients had an overall single stage SFR of 98.3%, which was significantly higher than single-stage SFR of 83% in Group 2 (50/60) (p < 0.002). Group 2 patients had a higher incidence of fever (10 vs 4, p = 0.01). However, there were no cases of sepsis in either group. Rest of the complications were comparable for both, as the need for ancillary procedures was significantly higher in Group 2 (10% vs 1.7%, p < 0.001). Patients were discharged on the same day in both groups. Conclusions: The findings of our study suggest that, in large and impacted proximal ureteric stones, combined minimally invasive endoscopic approach offers the best option to render the patient stone free by a single intervention. With better intra- and postoperative outcomes and safety profile, Mini-ECIRS may be considered as an ambulatory procedure in this setting.

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.

Ultrasound-guided mini-percutaneous nephrolithotomy in the treatment of upper urinary tract stones in children: A single-center evaluation

To evaluate the safety and efficacy of ultrasound-guided mini-percutaneous nephrolithotomy (mini-perc) for the treatment of upper urinary tract stones in children. We reviewed the records of 70 children with upper urinary tract stones who were treated with a mini-perc technique between July 2015 and April 2020. All puncture site selections and tract dilations were determined by Doppler ultrasonography. Patient age, height, weight, stone size, operation time, stone-free rate (SFR), postoperative complications, tubeless rate, and length of hospital stay (LOS) were recorded. Stone components were analysed using infrared spectroscopy. A total of 47 boys and 23 girls were included. Median weight and height of the patients were 18.5 kg and 110 cm, respectively. Median stone diameter was 2.0 cm. Median time to establish access was 4.0 min and median operation time was 25 min. Patients had median preoperative and postoperative haemoglobin levels of 121 and 113.5 g/L, median haemoglobin levels dropped to 8.0 g/L the day after surgery. No patient needed a blood transfusion. Eight children (11.4%) developed significant complications, including four cases with Clavien Grade I, one with Clavien Grade II, and three with Clavien Grade Ⅲ complications. One-day and 1-month follow-ups revealed a complete SFR of 95.7% (67/70) and 97.1% (68/70), respectively. Fifty-six patients (80.0%) did not require catheters of any type (total tubeless). Median LOS was 2.0 days. Ultrasound-guided mini-perc is safe and effective. The mini-perc technique is a feasible alternative for paediatric stone disease that does not result in major complications.

The effect of anesthesia type on the outcomes of percutaneous nephrolithotomy in elderly males

Objective: To compare the anaesthesia methods in percutaneous nephrolithotomy in terms of safety and effectiveness in elderly men.Methods: Elderly male patients who had undergone percutaneous nephrolithotomy were screened retrospectively and divided into 2 groups: percutaneous nephrolithotomy under combined spino-epidural anaesthesia (Group CSEA, n = 70) and percutaneous nephrolithotomy under general anaesthesia (Group GA, n = 114). Preoperative, perioperative and postoperative outcome measures were examined.Results: Between the two groups, there was no statistically significant difference in terms of stone burden, stone location, presence of the previous operation in the same kidney, presence of staghorn stones, mean American Society of Anesthesiologists scores and presence of abnormal kidney (p > 0.05). The mean duration time in the operation room and post-anaesthesia care unit (PACU) was statistically shorter in the Group CSEA (p < 0.01). There was no significant difference between the two groups in terms of Clavien Grade 1 and above complications (p > 0.05). Stone-free rates and success rates were similar in both groups (p = 0.133 and p = 0.273, respectively).Conclusion: The type of anaesthesia does not affect the success rate and complication rate of percutaneous nephrolithotomy in elderly male patients. Patients who underwent percutaneous nephrolithotomy under CSEA needed less analgesic injection during the postoperative period. CSEA can shorten the time a patient spends in the operating room and PACU, which provides more effective use of operation room working hours.

Optimization of the outcome of percutaneous nephrolithotomy regarding urinary leakage, what should we do?

To evaluate the factors affecting urinary leakage post percutaneous nephrolithotomy. To define those at high risk in whom a double J stent for 4 weeks or external ureteral catheter fixation for at least 3 days is indicated at the end of procedure. A total of 140 patients who underwent single-stage Percutaneous Nephrolithotomy (PCNL) with single or multiple accesses were included between February 2014 and March 2019. A detailed history, laboratory and radiological investigations were performed on all patients. All patients were classified according to postoperative urinary leakage into three groups. We defined leakage as a leakage from percutaneous puncture site. Group 1 (90 patients), No leakage was defined as leakage < 12 hours. In group 2 (32 patients), short-term leakage was defined as leakage 12-48 hours, and in Group 3 (18 patients), prolonged urinary leakage > 48 hours. Patients with short-term and prolonged urinary leakage had a significantly shorter access tract. Most patients (93.8%) with short-term leakage had an access tract of 71-90 mm, while > 50% of patients (55.6) with prolonged leakage had an access tract of 51-70 mm (p <0.001). Multivariate ordinal regression revealed that Operative time, length of the access tract and parenchymal thicknesses significantly predict short-term and prolonged leakage. For predicting the prolonged urinary leakage, the length of access tract and parenchymalthickness showed significant areas under the curve (AUC); 78% (95% CI: 69 - 85, p = 0.002) and 94% (95% CI: 87 - 97, p <0.001), respectively. Operative time, length of the access tract and parenchymal thickness significantly predict short-term and prolonged leakage.

Factors Predicting Outcomes of Supine Percutaneous Nephrolithotomy: Large Single-Centre Experience

Objective: Percutaneous nephrolithotomy (PCNL) is the treatment of choice for large renal calculi. The prone position has been considered the preferred position to obtain renal access. However, the supine position has recently gained popularity, which confers several potential advantages. The current study analyses the prognostic factors for successful supine PCNL procedures in a larger tertiary centre. Subjects: Prospective data were collected from all patients undergoing PCNL in the Galdako modified Valdivia position at our institution between February-2007 and September-2020. Surgical outcomes variables collected included: the rate of Endoscopic-combined intra-renal surgery (ECIRS), operative times, surgical effectiveness (no residuals <2 mm stone fragments) and complications. Results: A total of 592 patients underwent PCNL with a median age of 56 years (IQR: 42−67). The median stone size was 17 mm (IQR: 13−23). Of those, 79% of patients had an effective procedure. Stone size (p < 0.001), location (p < 0.001) and Guys-Stone Score (GSS) (p < 0.001) were associated with effectiveness. A Percutaneous nephrostomy tube was sited at the completion of the procedure in 97.3% of patients and a simultaneous double-J stent in 45.3%. Stent insertion was associated with larger stones (p < 0.001), the performance of ECIRS (p < 0.001) and higher GSS (p < 0.001). The overall complication rate was 21.7%. The main type of complication was an infection in 26.2 of the cases followed by the need for repeated nephrostogram in 12.7%. Conclusions: We demonstrate that PCNL in a high-volume centre is safe and efficacious in the Galdalko modified Valdivia position. Patients with smaller stones in the renal pelvis and a low GSS have the highest chance of a successful procedure.

A novel nomogram and a simple scoring system for urinary leakage after percutaneous nephrolithotomy

Introduction:

The present study aimed to investigate the factors of prolonged urinary leakage (PUL) after percutaneous nephrolithotomy (PCNL) and develop a new and simple scoring system to predict it.

Patients and Methods:

We retrospectively reviewed patients with renal stones who underwent PCNL at the University of Health Sciences Izmir Bozyaka Training and Research Hospital between April 2011 and January 2020. The patients were divided into two groups according to the presence of PUL, and their preoperative and perioperative data were compared. A multivariate regression analysis was applied to examine the relationship between perioperative descriptors and PUL, and a nomogram was developed using significant predictors. Then, the individual components of the nomogram were assigned points to form a scoring system.

Results:

There were 92 and 840 patients in the groups with and without PUL, respectively. The results of the univariate logistic regression analysis showed that hydronephrosis grade, parenchymal thickness, duration of nephroscopy, and duration of nephrostomy catheter were significantly associated with PUL. Subsequently, a multivariate regression analysis was carried out with these four factors as possible independent risk factors of PUL after PCNL. Based on the results of this analysis, a nomogram prediction model was developed with an area under the curve value of 0.811, which was consequently used to develop a new simple score system consisting of three characteristics: parenchymal thickness (1–5 points), duration of nephroscopy (1–3 points), and hydronephrosis grade (1–3 points).

Conclusion:

A novel scoring system is a useful tool for predicting PUL in patients who have undergone percutaneous nephrolithotomy.

Mini-Percutaneous Nephrolithotomy With an Endoscopic Surgical Monitoring System for the Management of Renal Stones: A Retrospective Evaluation

Purpose

To compare the outcomes and postoperative quality of life of patients with renal calculi who underwent standard percutaneous nephrolithotomy (sPNL), mini-invasive percutaneous nephrolithotomy (mPNL) or mPNL with an endoscopic surgical monitoring system (ESMS) using a retrospective clinical trial.

Methods

Eighty-six adult patients with renal stones who were treated with sPNL were retrospectively compared to ninety-two patients who were treated with mPNL between July 2014 and December 2017. Next, further studies were retrospectively conducted using a matched paired method. The ninety-two patients treated with mPNL were divided into two groups based on whether the endoscopic surgical monitoring system (ESMS) was used (ESMS-mPNL vs. non-ESMS-mPNL). The ESMS used strain gauge transducers to measure the inflow and outflow of irrigation solution. Bleeding and fluid absorption during endoscopic surgery could be accurately calculated by computer program in ESMS.

Results

The fluoroscopy time, complication rate, stone-free status and clinically insignificant residual fragment (CIRF) rate were not significantly different between the two groups (sPNL vs. mPNL). The mPNL group had a significantly longer operation time than the sPNL group, and the mPNL group exhibited a markedly reduced 12-h postoperative visual analogue pain scale (VAS) score, mean hospitalization time, and return to work time, had slightly reduced haemoglobin loss, and underwent more tubeless operations. Moreover, among the 92 patients who underwent mPNL, the operation time (P = 0.090), complication rate (P = 0.996), stone-free status (P = 0.731), CIRF rates (P = 0.125) and number of tubeless operations (P = 0.760) were not significantly different between the two subgroups (non-ESMS-mPNL vs. ESMS-mPNL); however, the patients in the ESMS-mPNL group had significantly longer irrigation times than those in the non-ESMS-mPNL subgroup, along with marked reductions in irrigation fluid, blood loss, haemoglobin loss, 12 h postoperative VAS score, mean hospitalization time, and return to work time.

Conclusions

mPNL is less painful than sPNL in patients undergoing treatment for 20–40 mm renal stones. Similar stone-free rates were achieved by the two procedures, but mPNL was superior to sPNL in terms of blood loss, discomfort, hospitalization time and return to work time. We think that ESMS-mPNL is less painful for patients and more efficacious than non-ESMS-mPNL, and ESMS-mPNL achieves a stone-free rate that is similar to non-ESMS-mPNL in patients receiving treatment for 20–40 mm kidney stones.

Totally ultrasound-guided minimally invasive percutaneous nephrolithotomy in children: Is it safe?

OBJECTIVE

The objective of the study was to assess the outcome and feasibility of ultrasonography (US)-guided minimally invasive percutaneous nephrolithotomy (mini-PCNL) in children.

MATERIALS AND METHODS

Twenty-five children with upper urinary tract stones who had undergone US-guided mini-PCNL from June 2017 to June 2020 were enrolled in this study. Patients' demographic information and post-treatment results were retrospectively gathered and analysed. Pyelocaliceal system was punctured in prone position using US guidance, and the tract was dilated using single-shot dilation technique. All steps of renal access were done using only US. Mini-PCNL in all cases was done by using 15 Fr rigid nephroscope. Stones were fragmented with a pneumatic lithotripter and evacuated.

RESULTS

The patients' mean age was 6.30 ± 3.25 years (range: 1.5-15). The mean stone size was 16.04 ± 3.93 mm (range: 10-30). The mean access time to the stone was 1.50 ± 0.62 min (range: 1-4). The mean operation time was 94.66 ± 3.05 min (range: 90-100 min). The final stone-free rate was 96%. Post-operation fever occurred in 4 (16%) patients who were treated successfully with an antibiotic. No major complications occurred.

CONCLUSIONS

We recommend US-guided mini-PCNL as a harmless alternative treatment option, in children with renal calculi due to its excellent outcomes and little complications.

Nomogram for predicting risk factor of urosepsis in patients with diabetes after percutaneous nephrolithotomy

Background

Urosepsis is an infectious complication after percutaneous nephrolithotomy (PCNL). This study aimed to analyze the perioperative factors related to urosepsis after PCNL for upper urinary calculi and establish a nomogram to predict the probability of postoperative urosepsis based on the risk factors.

Methods

The Clinical data of one-stage PCNL for upper urinary stones in patients already diagnosed with type 2 diabetes between June 2010 and June 2020 were retrospectively analyzed. The patients were divided into two groups according to whether urosepsis occurred after surgery, and univariate and multivariate logistic regression analyses evaluated the risk factors for urosepsis. Moreover, the corresponding nomogram prediction model was determined by the regression coefficient.

Results

All 366 patients with diabetes underwent one-stage PCNL. Seventy-one (19.4%) patients had urosepsis after surgery, and their hospitalization time was longer than that of patients without urosepsis. Moreover, the incidence of non-infection-related complications was higher. Multivariate logistic regression analysis revealed four independent risk factors associated with postoperative urosepsis, including positive urine nitrite (odds ratio [OR] = 3.326, P = 0.007), positive urine culture (OR = 2.213, P = 0.023), intraoperative hypotension (OR = 8.968, P < 0.001), and staghorn calculi (OR = 3.180, P = 0.002). The above independent risk factors were used as variables to construct the nomogram. The nomogram model was internally validated. The calculated concordance index was 0.824. The Hosmer–Lemeshow goodness-of-fit test was performed (P = 0.972 > 0.05). The area under the curve of this model was 0.831, indicating that the nomogram model had good accuracy in predicting the probability of urosepsis in patients who underwent PCNL with diabetes and had good consistency with the actual risk.

Conclusion

Positive urine culture, positive urine nitrite, staghorn calculi, and intraoperative hypotension were independent risk factors for urosepsis in patients who underwent one-stage PCNL with diabetes. The new nomogram could accurately assess the risk of urosepsis after PCNL in patients with diabetes.

Stones hounsfield unit value and predictors of urinary leakage after PCNL

Background

To evaluate the predictive factors of urinary leakage (UL) following percutaneous nephrolithotomy (PNL) and to investigate the relationship between Hounsfield unit (HU) of stone and UL.

Methods

We retrospectively reviewed the data of 728 patients who underwent PNL between January 2012 and January 2017. In total, 396 patients were eligible for the study. Patient demographics, renal factors, stone properties and operative details were collected. The association between UL and these variables were assessed by univariate and multivariate analysis.

Results

There was no statistically significant correlation considering age, body mass index and the presence of hypertension. The presence of diabetes mellitus (DM) was significantly correlated with UL (p < 0.001). Kidney related factors such as parenchymal thickness, hydronephrosis grade (HN), previous stone treatment, and stone related factors, such as stone surface area, stone burden, stone localization and HU value of stone, were found to affect UL status significantly (p < 0.001). Operation time, fluoroscopy time, treatment outcome, j stent use, percutenous nephrostomy (PCN) catheter stay time and the hospitalization time also had significant effect on UL (p < 0.001). Multivariable logistic analysis showed that presence of DM, parenchymal thickness, HU values, HN, operation time, j stent use, and PCN catheter stay time are independently related with UL following PCNL. Moreover, we determined a HU cut-off value of 933 with ROC analysis, which demostrated 84.9% sensitivity and 67.1% specificity for predicting UL.

Conclusion

This study has shown that we are more likely to encounter postoperative UL in stones with higher HU values. Therefore, we suggest clinicians to inform patients with this type of kidney stones about the probable complication of UL.

Flank free modified supine versus prone ultra mini percutaneous nephrolithotomy in treatment of medium sized renal pelvic stone a randomized clinical trial

INTRODUCTION & OBJECTIVES

percutaneous nephrolithotomy (PNL) is the standard treatment of renal stone more than 2 cm. ultra-mini-percutaneous nephrolithotomy had emerged in the last decade as a new technique in treating renal stones less than 2 cm. in this study we compare between outcomes of (UMP) in modified flank free supine (FFSP), and prone position.

MATERIALS & METHODS

A prospective randomized study was conducted between January 2016 and April 2020, including 122 patients, divided into two matched groups. Group A included 61 patients who underwent UMP in FFSP, and group B included 61 patients who underwent UMP in a prone position. All patients had a single renal pelvic stone 1-2 cm. Patients with a single kidney, renal anomalies, BMI≥40, history of ipsilateral renal surgery, and age less than 18 years were excluded. In both groups, the dilatation was done up to 13 f; a holmium laser was used through a 9f ureteroscope for fragmentation. Nephrostomy tube and ureteric stent were used only when indicated.

RESULTS

122 patients who divided into two groups. The mean age was 40.09±13.63 and 39.67±13.80 years in both groups, respectively. The operative time was 63.64±9.22 and 78.48±9.55 minutes in groups A &B, respectively (P=0.0001). The fluoroscopy time was 3.47±0.56 and 4.45±0.39 minutes in groups A &B, respectively (P=0.0001).no significant difference between both groups regarding operative and post-operative complications. Shift to miniPNL was needed in one patient in group A and four patients in group B due to impaired vision. The hospital stay was 25.36±4.23 and 26.13±4.76 hours in both groups, respectively. The initial stone-free rate was 95.1% and 91.8% in both groups, respectively.

CONCLUSIONS

ultra-mini-percutaneous nephrolithotomy in modified supine position shows comparable results to the prone position regarding stone-free rate, hospital stay, and perioperative complication, with significantly shorter operative and fluoroscopy time.

Does nephrolithometry scoring systems predict success and complications in miniPCNL?

OBJECTIVE

Auxiliary nephrolithometric scoring systems (NSSs) have been developed to predict complications and treatment success of conventional percutaneous nephrolithotomy (PCNL). However, to our knowledge, there is no study comparing these NSSs in patients undergoing miniPCNL. This study aimed to compare the NSSs in terms of their ability to predict miniPCNL-related complications and treatment success.

METHODS

The data of patients undergoing PCNL between September 2016 and May 2018 were retrospectively reviewed through the electronic medical record system, and 140 patients were included in our study. Stone-free status was evaluated using non-contrast computed tomography between 1 and 3 months after the procedure. PCNL was considered successful if the patient was completely stone free. The postsurgical complications were classified according to the modified Clavien-Dindo classification system.

RESULTS

The Clinical Research Office of the Endourological Society (CROES) and STONE NSSs significantly predicted miniPCNL treatment success (p = 0.043, p = 0.018). However, the Guy's NSS did not significantly predict the treatment success (p = 0.415). Guy's, CROES and STONE NSSs were not found to significantly predict postsurgical complications (p = 0.584, p = 0.823, p = 0.189).

CONCLUSION

To the best of our knowledge, our study is the first of its kind to investigate the ability of NSSs to predict treatment success and postsurgical complications in patients undergoing miniPCNL. The study found that STONE and CROES NSSs are independent parameters for predicting stone-free status after miniPCNL. In addition, our study found that none of the NSSs were useful in predicting postsurgical complications in patients undergoing miniPCNL.

Is Mini Percutaneous Nephrolithotomy a Game Changer for the Treatment of Renal Stones in Children?

Background

Mini percutaneous nephrolithotomy (MPCNL) is a newer surgical procedure that has changed the management of paediatric renal stones.

Objective

To evaluate MPCNL morbidity and success rates for renal stones as a function of patient age in a paediatric cohort.

Design, setting, and participants

This was a retrospective case series that included 143 consecutive patients younger than 17 yr who underwent MPCNL at our institution between January 2016 and November 2020. The patients were categorised into three different age groups: <6 yr (n = 71, 49.7%), 6–11 yr (n = 44, 30.8%), and 12–17 yr (n = 28, 19.6%). MPCNL was performed in all patients through 16–20Fr tracts.

Outcome measurements and statistical analysis

The stone-free rate, perioperative complications, tract number, operative time, postoperative haemoglobin change, and hospitalisation time were evaluated for each age group.

Results and limitations

MPCNL was performed in 143 paediatric patients (88 boys and 55 girls; mean age 6.53 yr). The mean stone burden (± standard deviation) was 2.096 ± 1.01 cm in group one, 2.05 ± 1.05 cm in group two, and 3.46 ± 19.94 cm in group three; group three was significantly larger (p = 0.001). After a single MPCNL session, 92.42% of patients experienced complete stone clearance. All age groups were similar in terms of stone-free rate (p = 0.82), hospitalisation time (p = 0.94), postoperative haemoglobin change (p = 0.06), and perioperative complications (p = 0.62). However, stone size (p = 0.009), stone complexity (p = 0.001), number of access points (p = 0.03), and operative time (p = 0.009) were higher in the group aged 12–17 yr.

Conclusions

MPCNL is an effective and safe procedure in younger as well as older children. Age should not be considered a limiting factor for MPCNL in children, and MPCNL should be considered the primary option for treating paediatric renal stones when PCNL is indicated.

Patient summary

Our results show that surgical removal of kidney stones through an incision in the skin and using miniaturised instruments is an effective and safe procedure for children.

Comparison of Outcomes of Percutaneous Nephrolithotomy (PCNL) Between Adults and Pediatrics Population: A Single-Center Retrospective Study

Introduction: Percutaneous nephrolithotomy (PCNL) has almost completely replaced open surgery for kidney stones because of continuous advancements in the method since the first PCNL was performed in 1976. The aim of this study is to compare the characteristics and outcomes of adult patients and pediatric patients who had undergone PCNL.

Methodology: A retrospective study was conducted at the Sindh Institute of Urology and Transplantation (SIUT) Hospital in Karachi, Pakistan. It included the data of patients who underwent PCNL from January 2015 to January 2022 at the SIUT hospital. The primary outcome variable was the stone-free rate (SFR). Secondary outcomes included length of hospital stay, and complications were assessed using modified Clavien classification system

Results: There is no significant difference in the SFR at discharge between pediatric and adult patients (86.67% vs 88.69%, p=0.634). There is no significant difference between the two groups in relation to the total length of hospital stay (p=0.446). Moreover, 12.50% and 11.11% of adults and children developed complications, respectively, after the procedure. The percentages are not significantly different between the two groups (p=0.266).

Conclusion: The current study using standardized and consistent PCNL techniques shows that SFR is similar in both adults and children, and there is no difference in complications between adults and children.

The Life and Death of Percutaneous Stone Removal: "Looking Back-Looking Forward"

Although percutaneous nephrolithotomy (PCNL) is less morbid than open surgery, it still carries risks of significant complications as well as injury to the renal parenchyma. Flexible ureteroscopic stone removal, although causes no appreciable damage to the renal parenchyma, has limitations, most notably, a lower stone-free rate than PCNL. Advances in our knowledge regarding ureteral physiology combined with technical developments applied to ureteral access sheath deployment and size may well propel retrograde intrarenal surgery to the forefront of kidney stone removal, regardless of stone size or location.

Postoperative infective complications following percutaneous nephrolithotomy

Introduction

Percutaneous nephrolithotomy (PCNL) is recommended as the first choice of therapeutic strategy for patients with renal stones larger than 2 cm. It is reported that up to one-third of patients might have some perioperative complications, especially fever and urinary tract infections, which constitutes about 21%-39.8% of all the complications.

Primary and Secondary

The primary aim of the study was to study about the proportion of patients getting post-operative infective complications following PCNL. The secondary aim was to study the patient, stone and procedure related risk factors associated with the infective complications.

Settings and Design

This is an institution-based observational study.

Materials and Methods

All patients who underwent PCNL in the Department of Urology, Medical College, Thiruvananthapuram, during 3 years from September 2016- to August 2019, were included in the study. In this study, the demographic factors and factors related to the patient, stone, and the procedure were collected and analyzed.

Statistical Analysis Used

Data analysis was performed using SPSS version 22.0.

Results

During the 3-year period, a total of 201 patients with renal stones were treated with PCNL in our hospital. Of this 190 cases were taken for analysis. The mean age of patients was 47.7 years, 148 (77.9%) were male, 42 (22.1%) were female, The final outcomes evaluated were episodes of fever, documented urinary tract infection (UTI), pyelonephritis, and sepsis. Thirty-six (18.9%) patients had fever, of which 21 (11.1%) had UTI, 6 (3.1%) had pyelonephritis and 5 (2.6%) developed sepsis.

Conclusions

Post-PCNL complications are more commonly found in patients with history of preoperative UTI, previous history of renal surgeries, large stone burden, operative procedure more than 90 min, and presence of residual calculi.

A single centre experience of percutaneous nephrolithotomy in infants and its long-term outcomes

BACKGROUND

Renal stones in infants requiring Percutaneous nephrolithotomy (PCNL) is rare. There is insufficient literature on the long-term implications of PCNL in growing kidneys of these children.

OBJECTIVES

To review our experience of PCNL amongst infants i.e., < 1year of age and to analyse the safety and efficacy of this procedure and assess its long-term renal outcomes.

STUDY DESIGN

This was a retrospective analysis of a prospectively maintained data base between 2005 and 2020. All infants with unilateral renal stones >12 mm underwent PCNL. Changes in the serum creatinine, estimated glomerular filtration rate and renal size prior to the PCNL and at the last follow up were monitored. The demographics, clinical profile, operative details, post-operative complications and follow up data were collated and analyzed.

RESULTS

86 children were diagnosed with renal stones of whom, 24 infants met our inclusion criteria and were included in the review. The average age was 9.75 months with fever being the commonest presenting symptom. Five infants were diagnosed with metabolic abnormalities, hypercalciuria being the commonest. Majority of the infants (22) had single stones and the lower calyx was the commonest site (50%). The mean stone burden was 19.5 mm. The stone free rate was 91% during the primary PCNL, which increased to 100% after re-do PCNL. The overall complication rate was 16% which was graded by the modified Clavien Dindo scale for surgical complications. The median follow up period was 144 months and average age at the last follow up was 10.5 years. At the last follow up, a mean serum creatinine of 0.4 mg/dl, mean estimated glomerular filtration rate of 98 ml/min/1.72 m² and a mean renal size of 8.3 cm was recorded, which was comparable to that of a normal child, thus signifying no deterioration of renal functions and renal growth. Three children showed the presence of cortical scars on an isotope scan at follow up. However, all the 24 operated renal units demonstrated preserved renal functions.

DISCUSSION & CONCLUSION

PCNL performed during infancy does not hinder the growth potential of the kidney. Each of the 24 children achieved the target renal size and estimated glomerular filtration rate corresponding to the duration and body size at the end of the follow-up. Thus, PCNL in infants <1 year of age is safe and effective with no adverse effects at long term follow-up.

The comparison of perioperative outcomes between percutaneous nephrolithotomy and retrograde intrarenal surgery in elderly patients

OBJECTIVES

In this study, we aimed to compare the outcomes and complication rates of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) in elderly patients.

MATERIALS AND METHODS

Between April 2011 and January 2020, patients who underwent PCNL and RIRS for renal stone in elderly patients were retrospectively evaluated. The two groups' perioperative values, stone-free rates and complication rates were compared. Post-operative complications were noted according to the Clavien scoring system.

RESULTS

There were 89 and 72 patients in the PCNL and RIRS group respectively. The median age was 67 years in both the groups (P = .192). The stone size were 22.2 ± 3.5 mm and 19.9 ± 7.1 mm in the PCNL and RIRS group, respectively (P = .082). Stone-free rates were significantly higher in PCNL group (P = .021, P = .034). Also we found that overall complication and major complication rates were significantly higher in PCNL group (P = .016, P = .029).

CONCLUSION

Despite there was higher stone clearance in PCNL, the complication rates were higher compared with RIRS. So RIRS might be a safe alternative treatment method to PCNL in older patients.

Minimal invasive percutaneous nephrolithotomy (Mini-PCNL) in children: Ultrasound versus fluoroscopic guidance

BACKGROUND

Miniaturization of endoscopic instruments in percutaneous nephrolithotomy (PCNL) allowed less invasive procedures with low complication rates, especially in children. This study was conducted to evaluate the safety and efficacy of ultrasonography-guided (USG) versus fluoroscopy-guided (FG) mini-PCNL in children.

MATERIALS AND METHODS

This is a retrospective comparative study conducted from June 2015 to June 2020. The sample included 70 children (35 pateints underwent USG mini-PCNL and 35 pateints underwent FG mini-PCNL). They were compared mainly by the patients' demographic characteristics, procedural information, and post-treatment outcomes. In the USG mini-PCNL group, puncturing was performed using a 3.5 MHz US probe, whereas fluoroscopy was utilized in the FG mini- PCNL group.

RESULTS

Both groups were comparable in terms of gender, previous history of failed ESWL, and hydronephrosis grade. The mean stone burden was 15.94 ± 3.69 mm and 19.20 ± 7.41 mm in USG and FG groups, respectively (p = 0.024). The stonefree rate (SFR) was 97.1% in the USG group and 94.3% in the FG group, which was not statistically significant (p = 0.16). Mean operative time in the USG group and FG group was 69.00 ± 13.33 minutes and 63.48 ± 16.90 minutes, respectively. Four (11.4%) patients in the FG group required blood transfusions to restore the hemodynamic state (p = 0.039). Fever was detected in 4 (11.4%) patients in the USG group and 15 (31.4%) patients in the FG group (p = 0.041).

CONCLUSIONS

In children, mini PCNL under USG is safe and as effective as fluoroscopy.

Percutaneous nephrolithotomy outcomes based on body mass index: A 5-year retrospective study in an Indonesian tertiary hospital

Objectives:

The aim of this study was to evaluate the impact of body mass index (BMI) on percutaneous nephrolithotomy (PCNL) outcomes and complications for nephrolithiasis.

Patients and methods:

Patients with a history of PCNL surgery from 2012 to 2017 in Dr. Soetomo General-Academic Hospital were retrospectively evaluated. Patients were then categorized into four groups: underweight (BMI <18.5 kg/m2), normal (BMI 18.5 to 24.99 kg/m2), overweight (BMI ⩾25–29.9 kg/m2), and obese (BMI ⩾30 kg/m2). The association between BMI, subjects’ characteristics, length of stay, stone-free rate (SFR), and complications were analyzed using one-way analysis of variance (ANOVA) and univariate logistic regression.

Results:

The study included 430 male patients (58%) and 310 female patients (42%). They were classified based on their BMI into underweight ( n = 5, 1%), normal weight ( n = 291, 39%), overweight ( n = 271, 37%), and obese ( n = 173, 23%) groups. The underweight BMI group had a higher average blood loss ( p=0.002) compared to the other groups; however, the univariate logistic regression showed that BMI had no significant effect on SFR ( p=0.491).

Conclusion:

PCNL is safe and feasible to be performed in patients with different BMI as obesity has no impact on the outcomes and complications associated with PCNL.

Level of evidence

3

Outcome of Mini-Percutaneous Nephrolithotomy in Patients Under the Age of 18: An Experience With 112 Cases

Purpose: Renal calculi are becoming more common among children. Although, extracorporeal shock wave lithotripsy (ESWL) is the first choice in this age group, minimal invasive surgeries, such as percutaneous nephrolithotomy (PCNL), are indicated for some patients. Recently, PCNL devices have become smaller in size with acceptable efficacy and lower complications. We evaluated the outcomes and complications of mini-PCNL (MPCNL) surgery in our referral training centers.

Materials and Methods: Between September 2012 and January 2020, a total of 112 children under the age of 18, who had shown failure of ESWL, and/or their parents refused to do it, underwent MPCNL (15 Fr). The patients' profiles were reviewed for data collection including preoperative and stone data, operation information, and postoperative complications.

Results: Of 112 patients, 69 were boys, and 43 were girls. Their mean age was 8.6 years (14 months to 18 years). Mean stone size was 20 mm (14–34 mm). Seventy-four cases had renal pelvic stone, 22 had pelvis and lower pole, and 16 had staghorn. The mean operation time was 65 min (35–100 min), and mean radiation time was 0.6 min (0.2–1.4 min). Low-grade fever was detected in 14 patients (12.5%). Four patients needed blood transfusion and two had increased creatinine, which improved with conservative management. One patient developed urosepsis that resolved with antibiotic therapy. None of the patients had kidney perforation or other organ injury or death. Early stone-free rate (SFR) after operation was 90.2% (101 patients). Six patients had residual fragment <5 mm, which passed spontaneously in 2 weeks after operation (total SFR 95.3%). Three patients underwent second-look nephroscopy, and ureteroscopy was done for two patients due to migrated stone fragments to the distal ureter.

Conclusion: MPCNL is recommended as a safe alternative option for treatment of the nephrolithiasis in children with good outcome and acceptable complications.

Antibiotic administration for negative midstream urine culture patients before percutaneous nephrolithotomy

To investigate how to administrate antibiotics for negative midstream urine culture (UC-) patients prior to percutaneous nephrolithotomy (PCNL), we retrospectively analyzed UC-patients receiving 0 or 3 days of cefuroxime prior to PCNL between July 2017 and May 2020. Patients were further divided into four groups (Group1A = urine with positive both nitrite and white blood cell (N + WBC +) and 0-day pre-operative cefuroxime; Group1B = N + WBC + and 3-day cefuroxime; Group2A = N - WBC + and 0-day cefuroxime; Group2B = N - WBC + and 3-day cefuroxime). All patients routinely received a dose of cefuroxime 30 min prior to the surgery. In addition, Group1B were matched to the Group1A; Group2B were matched to the Group2A at a 1:1 ratio regarding stone burden, the degree of hydronephrosis, stone hardness, age and sex in a sequential order. A total of 560 patients were included (Group1A = 72; Group1B = 72; Group2A = 208; Group2B = 208). The baseline characteristics were equally distributed between the matched-pair groups. Compared to Group1B, Group1A had a significantly higher incidence of SIRS, fever, urosepsis requiring only additional antibiotics, and an increased postoperative hospitalization stay. Compared to Group2B, Group2A had similar rate of infectious complications. In addition, Group1B was associated with a significantly lower rate of positive pelvic urine culture (PUC +) than that of Group1A; whereas, there was similar rate of PUC + between Group2A and Group2B. UC-patients with N + WBC + should be treated with extended period of antibiotic administration, and a single dose of prophylactic antibiotic was sufficient for UC-patients with N - WBC + prior to PCNL. Despite UC, it is suggested to stratify pre-operative antibiotics tailored to individual patients to optimize its application.

Comparison of standard- and mini-percutaneous nephrolithotomy for staghorn stones

Objectives: To compare the outcomes of standard- and mini-percutaneous nephrolithotomy (PCNL) for the treatment of staghorn stones.

Patients and Methods: The data of consecutive adult patients who underwent PCNL for the treatment of staghorn stones, between July 2015 and December 2019 from three hospitals, were retrospectively reviewed. All cases were performed in a prone position under fluoroscopic guidance. The nephrostomy tracts were dilatated to 30 F in standard-PCNL and to 18–20 F in mini-PCNL. Stones were fragmented with pneumatic lithotripsy in both groups. Fragments were removed with forceps in the standard-PCNL, while they were evacuated through the sheath using the vacuum clearance effect in mini-PCNL. A ureteric stent was inserted after mini-PCNL, while a nephrostomy tube was inserted after standard-PCNL.

Results: The study included 153 patients; 70 underwent standard-PCNL and 83 underwent mini-PCNL. The stone-free rates of PCNL monotherapy were comparable for both groups (83% for mini-PCNL and 88.6% for standard-PCNL, P = 0.339). The incidence (12% vs 24.3%, P = 0.048) and severity of complications were significantly lesser with mini-PCNL (P = 0.031). Standard-PCNL was associated with increased rate of blood transfusion (12.9% vs 2.4%, P = 0.013) and a significant decrease in haemoglobin (P = 0.018). Hospital stay was significantly longer for standard-PCNL than mini-PCNL (median stay of 6 vs 3 days, P < 0.001).

Conclusions: The efficacy of mini-PCNL was comparable to standard-PCNL in the treatment of staghorn stones. The advantages of mini-PCNL included a lesser incidence and severity of complications, and shorter hospital stay.

A systematic review and meta-analysis of minimally invasive vs. standard percutaneous nephrolithotomy in the surgical management of renal stones

The present study aimed to assess current evidence on the effectiveness and safety of minimally invasive vs. standard percutaneous nephrolithotomy (PCNL) in the management of renal stones. A systematic search of electronic databases, which included PubMed, EMBASE and the Cochrane Library up to May 2019 was performed. Using Review Manager statistical software (version 5.3), primary outcomes, including stone-free rates (SFRs), were evaluated. Meanwhile, analysis was also performed to compare secondary outcomes, such as peri- and postoperative complications and operative data. Fourteen studies involving 1,611 patients with renal stones were analyzed based on the inclusion criteria. On the basis of the present analysis, mini percutaneous nephrolithotomy (MPCNL) was proven to have non-inferior clinical efficacy with respect to the SFR compared with PCNL [odds ratio (OR)=1.10; 95% confidence interval (CI), 0.84-1.44; P=0.48]. In addition, the meta-analysis showed that MPCNL had a significantly lower hemoglobin decrease [mean difference (MD)=-0.68; 95% CI, -1.05 to -0.31; P=0.0003] and fewer blood transfusions (OR=0.36; 95% CI, 0.18-0.71; P=0.003) compared with PCNL. Moreover, the MPCNL group had a shorter inpatient stay (MD=-0.81; 95% CI, -1.55 to -0.08; P=0.03) compared with the PCNL group. However, the overall evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with PCNL. The present meta-analysis indicates that MPCNL is an effective method for treating renal stones. Compared with PCNL, MPCNL not only has similarly high SFRs but is also associated with less blood loss, fewer blood transfusions, more favorable recovery time and shorter inpatient stays. However, the findings of the present study should be further confirmed by well-designed prospective randomized controlled trials with a larger patient series.

Classification and standardized reporting of percutaneous nephrolithotomy (PCNL): International Alliance of Urolithiasis (IAU) Consensus Statements

BACKGROUND

The aim of this study was to reach a consensus in the classification and standardized reporting for the different types of PCNLs.

METHODS

The RAND/UCLA appropriateness methodology was used to reach a consensus. Thirty-two statements were formulated reviewing the literature on guidelines and consensus on PCNLs, and included procedure specific details, outcome measurements and a classification for PCNLs. Experts were invited to two rounds of input, the first enabled independent modifications of the proposed statements and provided the option to add statements. The second round facilitated scoring of all statements. Each statement was discussed in the third round to decide which statements to include. Any suggestion or disagreement was debated and discussed to reach a consensual agreement.

RESULTS

Twenty-five recommendations were identified to provide standardized reporting of procedure and outcomes. Consensual scoring above 80% were strongly agreed upon by the panel. The top treatment related outcomes were size of sheath used (99.1%) and position for PCNL (93.5%). The highest ranked Outcome Measures included definition of postoperative hospital length of stay (94.4%) and estimated blood loss (93.5%).

CONCLUSIONS

The consensus statements will be useful to clarify operative technique, in the design of clinical trials and standardized reporting, and presentation of results to compare outcomes of different types of PCNLs.

The Comprehensive Complication Index (CCI) for improved reporting of complications in endourological stone treatment

The Clavien-Dindo Classification (CDC) lacks a combined score of multiple complications in one patient. The comprehensive complication index (CCI) circumvents this problem making it a valuable instrument to optimize quality control. We aimed to introduce and validate CCI in the treatment of urolithiasis. 60 day postoperative complications of 327 consecutive patients undergoing percutaneous nephrolitholapaxy (PNL) and ureterorenoscopy (URS) between 2017 and 2019 were retrospectively assessed and graded according to CDC. CCI was calculated for each patient. Overall morbidity scores of CCI and CDC were compared. Correlation analyses between the two scores and length of hospital stay (LOS) were performed. A multivariate analysis was performed to identify predictive factors for complications. Sample size calculation for an imaginary clinical trial was compared between CCI and CDC. A significant difference in overall morbidity between CCI and CDC was revealed for PNL (p < 0.001) and URS (p = 0.001). There was no statistically significant difference in comparing correlations between cumulative CCI and LOS versus non-cumulative CDC and LOS for both cohorts. Operating time > 90 min, maximum stone size, positive preoperative urine culture and PNL type (p < 0.001) were predictive factors for postoperative complications in PNL, while urine culture (p = 0.02) was for URS. Sample size calculation based on CCI resulted in a significant reduction of required patients for PNL (- 48%) and URS (- 84%) compared to CDC. CCI could successfully be validated in endourological stone treatment with the advantage of assessing complications in their entirety compared to CDC. CCI can significantly reduce the required sample size in future clinical trials.

Feasibility and relevance of urine culture during stone fragmentation in patients undergoing percutaneous nephrolithotomy and retrograde intrarenal surgery: a prospective study

PURPOSE

We evaluated if, during lithotripsy, bacteria may be detected in the irrigation fluid of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). The concordance between urine culture from stone fragmentation (SFUC), bladder (BUC), renal pelvic (RPUC) and stone (SC) was analyzed. We also assessed the correlation between variables and cultures and their association with systemic inflammatory response syndrome (SIRS) and of a positive SC.

METHODS

We included 107 patients who underwent PCNL (n = 53) and RIRS (n = 54) from January 2017 to May 2018. Samples for RPUC were obtained by renal catheterization. Stone fragments and irrigation fluid sample were sent for culture.

RESULTS

SFUC was positive in 17 (15.9%), BUC in 22 (20.6%), RPUC in 26 (24.3%) and SC in 30 patients (28%). The concordance between SFUC and SC was the highest among all cultures: 94.1%. SFUC and SC grew identical microorganisms in 15/17 (88.2%) patients. Out of 17 (15.9%) patients with SIRS, 8 (7.5%) had sepsis. SFUC had the highest PPV and specificity to detect positive SC and SIRS. Previous urinary tract infection, a preoperative nephrostomy, stone diameter and composition, staghorn calculi, PCNL, positive BUC, RPUC and SFUC were predictors of infected stone. Variables that indicate complex stones, complex PCNL and an infection of the upper tract were associated with SIRS.

CONCLUSION

SFUC is technically feasible, easy to retrieve and to analyze. The spectrum of SFUC potential application in clinical practice is when is not possible to perform a SC, e.g. complete dusting or during micro-PCNL.

The impact of nephrostomy drainage prior to mini-percutaneous nephrolithotomy in patients with ESBL-positive Escherichia coli

OBJECTIVE

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is one of the most frightening multidrug-resistant bacteria that usually causes sepsis. Herein we explored the benefits of nephrostomy drainage prior to percutaneous nephrolithotomy (PCNL) on infection outcomes in patients with ESBL-EC.

PATIENTS AND METHODS

Between June 2016 and April 2019, 43 consecutive patients with ESBL-EC who received nephrostomy drainage for > 24 h prior to PCNL were retrospectively evaluated as group 1. 86 patients were randomly selected from patients with ESBL-EC who received concurrent percutaneous access during PCNL as group 2. The postoperative infection complications were compared.

RESULTS

Although the total infection complications were not statistically different (11.6% vs. 25.6%, p = 0.066), the severity seemed to be worse among group 2 subjects. Severe infections, including urosepsis (4.7% vs.13.9%) and septic shock (2.3% vs 4.6%), were observed at twice or greater rates in group 2. Blood transfusions were also more frequent (2.3% vs. 13.9%, p = 0.039). Multivariate analysis demonstrated that preoperative drainage was an independent risk factor for postoperative infection events (OR 2.31 CI 1.14-3.48, p = 0.017). Subgroup analyses indicated that preoperative drainage may largely reduce the incidence of urosepsis in patients with hydronephrosis or without receiving preoperative carbapenem therapy.

CONCLUSION

Because of the high rate of severe infection after PCNL in patients with ESBL‑positive E. coli, preoperative nephrostomy drainage for > 24 h is an effective measure to reduce the risk of severe infection complications, especially in patients with hydronephrosis or those without preoperative carbapenem therapy.