Lessons learned from the CROES percutaneous nephrolithotomy global study

The impact of chronic kidney disease stages and CROES AND GSS scores on stone free rate in kidney stones

INTRODUCTION

This study evaluates the impact of chronic kidney disease (CKD) stages on stone-free rates (SFR) and renal function outcomes after percutaneous nephrolithotomy (PCNL). Additionally, it examines the predictive role of the CROES and Guy's Stone Score (GSS) systems.

METHODS

Data from 2994 patients who underwent PCNL between 2007 and 2024 were retrospectively analyzed. Patients were classified into four CKD groups based on preoperative estimated glomerular filtration rate (eGFR). SFR, complication rates, and postoperative renal function changes were assessed.

RESULTS

SFR was significantly lower in advanced CKD stages (p < 0.001), with the lowest in Group A (GFR < 30, 64.1%) and highest in Group D (GFR > 90, 79.1%). Postoperative eGFR increased in CKD stage 4-5 but declined in normal kidney function groups. Complication rates were higher in advanced CKD stages (p = 0.031). CROES and GSS scores correlated with stone complexity and surgical outcomes (p < 0.001).

CONCLUSION

Advanced CKD is associated with lower SFR, greater surgical complexity, and higher complication rates. PCNL remains an effective treatment, particularly in CKD patients, with potential postoperative renal function improvement. Utilizing predictive scoring systems can optimize patient selection and surgical planning. Further prospective studies are needed to validate these findings.

A Global Survey to Assess Urologists' Attitudes Towards Suction Technology in Endourology by the European Association of Urology Section of Endourology and Progressive Endourological Association for Research and Leading Solutions

OBJECTIVE

To assess urologists' perceptions and current practices of using suction-based techniques and technologies in percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) for kidney stones.

MATERIALS AND METHODS

A customized web-based 28-item questionnaire was created. All participation was voluntary. The survey was hosted on Google Forms between November 15, 2023 and November 25, 2023. Descriptive statistics were applied to demographic details and categorical responses.

RESULTS

Six hundred thirty-two responses were received. 56.5% were from Asia. Around 41.6% of respondents underwent an endourology fellowship. Personal experience of suction for PCNL was noted in 55.4% and 42.7% for RIRS. Exactly 34.9% believe that currently there is enough evidence that suction can improve stone-free rates and lower complications for both endourology surgeries. Around 55.69% believe that as evidence evolves, suction has the potential to be a game changer in endourology management of urolithiasis. Exactly 55.7% believe that the leading barrier to the adoption of suction in endourology is the lack of availability of technology. Other barriers include lack of procedural standardization (37.65%), lack of evidence (34.9%), lack of proper training (29.58%) and lack of advocation in the current guidelines (17.72%).

CONCLUSION

Our survey shows that urologists are keen to adopt suction for PCNL and RIRS but the lack of definitive evidence, standardization, equipment availability and training preclude them from using so. More high-level evidence regarding the utility of suction in endourology is required for its routine adoption in clinical practice.

Evaluating postoperative complications in standard percutaneous nephrolithotomy for renal stones larger than 2 cm: a retrospective study utilizing the E-PASS scoring system

Percutaneous nephrolithotomy (PCNL) is a widely preferred method for treating complex kidney stones, particularly in patients with larger or more complicated stones. Despite its advantages, such as minimal invasiveness and a shorter recovery time, postoperative complications can occur, thereby necessitating effective risk assessment tools to identify at-risk patients. This study evaluated the Estimation of Physiologic Ability and Surgical Stress (E-PASS) scoring system's utility in predicting postoperative complications following standard PCNL. This retrospective study included 218 patients who underwent standard PCNL from June 2020 to August 2024 at our institution. Data on demographics, comorbidities, and perioperative factors were collected and analyzed. Postoperative complications were classified using the modified Clavien-Dindo system. The E-PASS scoring system, which incorporates the Preoperative Risk Score (PRS), Surgical Stress Score (SSS), and Comprehensive Risk Score (CRS), was applied to stratify risk. Postoperative complications occurred in 38 patients (17.4%). Significant predictors included advanced age, higher American Society of Anesthesiologists (ASA) scores, and comorbidities like diabetes and coronary artery disease. Intraoperative factors, such as prolonged operative times, number of access and greater blood loss, were also associated with complications. Multivariate analysis identified higher CRS and greater stone burden as independent predictors (p = 0.012 and p = 0.037, respectively). The CRS demonstrated moderate discrimination, with an area under the curve (AUC) of 0.747. The E-PASS scoring system effectively predicts postoperative complications in PCNL, underscoring the importance of thorough preoperative and intraoperative evaluation. Future studies should explore its broader applicability across other urological procedures.

Which is easier for beginners: supine or prone position percutaneous nephrolithotomy? Assessment of the learning curve in novice urologists through a randomized clinical trial

BACKGROUND

Percutaneous nephrolithotomy (PCNL) could be performed in both prone and supine positions. Each position has its own advantages and disadvantages. "Learning curve" is a graph that represents progress of a skill against the time needed to master the technique. We hypothesized that supine PCNL might have a shorter learning curve by novice urologists compared to prone PCNL based on the findings of previous studies assessing the learning curve of both techniques. The aim of this study is to assess the learning curve of prone and supine PCNL among novice urologists to detect which is easier for the beginners.

METHODS

One hundred and fifty patients undergoing PCNL for renal stones were included and divided into two groups; Group A included 75 patients undergoing supine PCNL and Group B included 75 patients undergoing prone PCNL. Subsequently, each group was subdivided into three subgroups of 25 patients to allow the evaluation of the learning curve of the two novice surgeons as regards: operative time, fluoroscopy time, stone free rate, and complications.

RESULTS

The mean operative time in group A decreased from of 111.8±13.91 minutes to 84.2±15.86 minutes, and thereafter, decreased to 78.4±12.97 minutes in the three consecutive subgroups. Similarly, in group B, the mean operative time decreased from 122±23.76 minutes to 110.2±17.05 minutes, and thereafter, further decreased to 82±15.34 minutes. The operative time plateau was reached after 25 and 50 cases in groups A and B, respectively. The overall stone free rate, and complications were comparable in both groups.

CONCLUSIONS

Both supine and prone PCNL are safe and effective; however, supine PCNL may be associated with significantly shorter learning curve.

Comparison of the efficacy and safety of mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of kidney stones in overweight or obese patients: a systematic review and meta-analysis

OBJECTIVE

To discuss the differences in the effectiveness and security of kidney stones in overweight or obese patients by mini percutaneous nephrolithotomy (MiniPCNL) and retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

We exhaustively searched numerous databases, including PubMed, Embase, Web of Science, Cochrane Library, and CNKI, covering all records from their initiation date until September 2023. This included controlled trials focusing on the use of MiniPCNL and RIRS in the treatment of kidney stones in overweight or obese patients. The gathered data was then analyzed using the Review Manager 5.4 software.

RESULTS

9 studies including 1122 patients were included. Meta-analysis showed that: The MiniPCNL group had higher overall complications, grade I complications, length of hospital stay(LOS), first stone-free rate (SFR), and final SFR in obese patients, with no significant difference between the two groups in terms of operative time(OT), hemoglobin drop, and grade II complication rate. There were more overall complications, grade I complications, final SFR, and LOS with MiniPCNL in patients with stones > 2 cm compared to no significant difference in grade II complications. MiniPCNL performed in the prone position had higher final SFR, less OT, hemoglobin drop, and no statistically significant difference in overall complications or LOS. Sheaths using > 14 F had higher overall complication rates, final SFR, and LOS, and no statistical differences in OT and first SFR between the two modalities. In the MiniPCNL subgroup aged ≤ 50 years, there were higher first SFR, final SFR, and shorter OT, and in the MiniPCNL subgroup aged > 50 years, there were more OT, LOS, and hemoglobin drop, with no statistical difference in overall complications between the two groups.

CONCLUSION

Our study showed that MiniPCNL in obese patients had higher initial SFR and final SFR, fewer procedures, but more postoperative complications, LOS, and grade I complications compared with RIRS. Similar results were seen in patients in the prone position, with stones > 2 cm and age ≤ 50 years.

SYSTEMATIC REVIEW REGISTRATION

[ https://www.crd.york.ac.uk/PROSPERO/ ], identifier PROSPERO (CRD42023467284).

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.

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

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

Percutaneous antegrade management of large proximal ureteral stones using non-papillary puncture

Objective

To evaluate the feasibility and the safety of medial non-papillary percutaneous nephrolithotomy (npPCNL) for the management of large proximal ureteral stones.

Methods

We evaluated prospectively collected data of 37 patients with large proximal ureteral stones more than 1.5 cm in diameter treated by prone npPCNL. Depending on stone size, in-toto stone removal or lithotripsy using the Lithoclast® Trilogy (EMS Medical, Nyon, Switzerland) was performed. Perioperative parameters including operative time (from start of puncture to the skin suturing), stone extraction time (from the first insertion of the nephroscope to the extraction of all stone fragments), and the stone-free rate were evaluated.

Results

Twenty-one males and 16 females underwent npPCNL for the management of large upper ureteral calculi. The median age and stone size of treated patients were 58 (interquartile range [IQR]: 51-69) years and 19.3 (IQR: 18.0-22.0) mm, respectively. The median operative time and stone extraction time were 25 (IQR: 21-29) min and 8 (IQR: 7-10) min, respectively. One case (2.7%) of postoperative bleeding and two cases (5.4%) of prolonged fever were managed conservatively. The stone-free rate at a 1-month follow-up was 94.6%.

Conclusion

The npPCNL provides a straight route to the ureteropelvic junction and proximal ureter. Approaching from a dilated portion of the ureter under low irrigation pressure with larger diameter instruments results in effective and safe stone extraction within a few minutes.

Suction in Percutaneous Nephrolithotripsy: Evolution, Development, and Outcomes from Experimental and Clinical studies. Results from a Systematic Review

CONTEXT

Controversy exists regarding the therapeutic benefit of suction use during percutaneous nephrolithotripsy (PCNL).

OBJECTIVE

To review and highlight the options available in the use of suction for PCNL, and to discuss their strengths and limitations.

EVIDENCE ACQUISITION

A systematic literature search was performed using Scopus, EMBASE, and PubMed. Thirty four studies were included. There was one ex vivo study. Among clinical studies, 24 used a vacuum/suctioning sheath and nine a handpiece suction device/direct-in-scope suction. The suction technique was employed in standard, mini-PCNL, supermini-PCNL, and enhanced supermini‑PCNL techniques.

EVIDENCE SYNTHESIS

Handpiece suction devices demonstrated better safety and efficiency in treating large stones than nonsuction PCNL and in a much shorter time. Trilogy and ShockPulse-SE were equally effective, safe, and versatile for standard PCNL and mini-PCNL. The heavier handpiece makes Trilogy less ergonomically friendly. Laser suction handpiece devices can potentiate laser lithotripsy by allowing for better laser control with simultaneous suction of small fragments and dust. Integrated suction-based sheaths are available in reusable and disposable forms for mini-PCNL only. Mini-PCNL with suction reported superior outcomes for operative time and stone-free rate to mini-PCNL. This also helped minimize infectious complications by a combination of intrarenal pressure reduction and faster aspiration of irrigation fluid reducing the risk of sepsis, enhance intraoperative vision, and improve lithotripsy efficiency, which makes it a very attractive evolution for PCNL.

CONCLUSIONS

Suction devices in PCNL are reforming the way PCNL is being done. Adding suction to mini-PCNL reduces infectious complications and improves the stone-free rate. Our review shows that despite the limited evidence, suction techniques appear to improve PCNL outcomes.

PATIENT SUMMARY

In this review, we looked at the intra- and perioperative outcomes of percutaneous nephrolithotripsy (PCNL) with the addition of suction. With better stone fragmentation and fewer postoperative infections, this technology is very useful particularly for mini-PCNL.

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

INTRODUCTION

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Design and internal validation of S.I.C.K.: a novel nomogram predicting infectious and hemorrhagic events after percutaneous nephrolithotomy

BACKGROUND

Hemorrhagic and infectious events represent severe complications after percutaneous nephrolithotomy (PCNLs). Existing nephrolithometric nomograms have been introduced but their reliability in predicting complications is debated. We present a newly designed nomogram with intention to predict hemorrhagic/infectious events after PCNLs.

METHODS

We conducted a multicentric prospective study on adult patients undergoing standard (24 Fr) or mini (18 Fr) PCNL. Dataset was derived from previous RCT, where patients have been assigned to mini-PCNL or standard-PCNL to treat renal stones up to 40 mm. Aim of the study was to identify preoperative risk factors for early postoperative infectious/hemorrhagic complications including fever, septic shock, transfusion or angioembolization.

RESULTS

A total of 1980 patients were finally included. 992 patients (50.1%) received mini-PCNL and 848 standard PCNL (49.9%). The overall SFR was 86.1% with a mean maximum stone diameter of 29 mm (SD 25.0-35.0). 178 patients (8.9%) had fever,14 (0.7%) urosepsis, 24 patients (1.2%) required transfusion and 18 (0.9%) angioembolization. The overall complication was (11.7%). After multivariable analysis, the included elements in the nomogram were age (P=0.041), BMI (P=0.018), maximum stone diameter (P<0.001), preoperative hemoglobin (P=0.005), type 1/2 diabetes (P=0.05), eGFR<30 (P=0.0032), hypertension (>135/85 mmHg, P=0.001), previous PCNL or pyelo/nephrolithotomy (P=0.0018), severe hydronephrosis (P=0.002). After internal validation, the AUC of the model was 0.73.

CONCLUSIONS

This is the first nomogram predicting infections and bleedings after PCNLs, it shows a good accuracy and can support clinicians in their patients' peri-operative workout and management.

Clinical Considerations for Patients Experiencing Acute Kidney Injury Following Percutaneous Nephrolithotomy

Acute kidney injury (AKI) is a common postoperative outcome in urology patients undergoing surgery for nephrolithiasis. The objective of this study was to determine the prevalence of postoperative AKI and its degrees of severity, identify risk factors, and understand the resultant outcomes of AKI in patients with nephrolithiasis undergoing percutaneous nephrolithotomy (PCNL). A cohort of patients admitted between 2012 and 2019 to a single tertiary-care institution who had undergone PCNL was retrospectively analyzed. Among 417 (n = 326 patients) encounters, 24.9% (n = 104) had AKI. Approximately one-quarter of AKI patients (n = 18) progressed to Stage 2 or higher AKI. Hypertension, peripheral vascular disease, chronic kidney disease, and chronic anemia were significant risk factors of post-PCNL AKI. Corticosteroids and antifungals were associated with increased odds of AKI. Cardiovascular, neurologic complications, sepsis, and prolonged intensive care unit (ICU) stay percentages were higher in AKI patients. Hospital and ICU length of stay was greater in the AKI group. Provided the limited literature regarding postoperative AKI following PCNL, and the detriment that AKI can have on clinical outcomes, it is important to continue studying this topic to better understand how to optimize patient care to address patient- and procedure-specific risk factors.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Pattern of key opinion leaders talks at major international urological meetings reflects the main differences in flexible ureteroscopy and PCNL diffusion

OBJECTIVE

To analyze the pattern of speaker activity related to both flexible ureteroscopy (fURS) and percutaneous nephrolithotomy (PCNL) during plenary sessions at the main (endo)urological international meetings over the last 10 years.

METHODS

We reviewed the meeting programs of the main endourological international meetings (EAU, AUA, WCE, and SIU) during 2011-2019. We detected all invited speakers at plenary sessions regarding fURS or PCNL. The proportion of fURS and PCNL talks was evaluated yearly during the study period. In order to analyze plenary session speaker composition, we estimated and compared the mean number of talks per speaker according to surgical technique. We also analyzed possible differences in age distribution according to the topic of the talk as well as the presence of young (i.e., < 45 years) speakers. Data were analyzed using descriptive statistics.

RESULTS

During the last 10 years, a total of 498 plenary talks were found. Of those, 260 (52.2%), 211 (42.4%), and 27 (5.4%) discussed PCNL, fURS, or both, respectively. PCNL was more frequently discussed at the beginning and the end of the study period. Mean [SD] number of talks per speaker was higher for PCNL (2.9 [3.4] vs 1.6 [1.4], p < 0.001), meaning that a wider variety of speakers was invited to give fURS talks. Speakers discussing fURS were younger (median [interquartile range, IQR] age 48 [44-56] vs 52 [47-60] years, p < 0.001), and a higher proportion of young speakers was observed in the fURS group (26% vs 15% p < 0.001). PCNL speakers were more commonly discussing fURS than fURS speakers discussing PCNL (23% vs 17%, p = 0.43).

CONCLUSIONS

We found a wider variety of speakers at fURS plenary sessions as compared to PCNL ones. It is easier and quicker to become an internationally recognized expert in the field of fURS rather than PCNL. PCNL speakers were able to master fURS more frequently than the other way around.

Retrorenal colon in pediatric patients with urolithiasis: Is the supine position for PCNL advantageous?

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is one of the main approaches for the treatment of large and complex stones in pediatric patients. The patient position for PCNL has been classically divided into prone or supine and the prone position is more commonly used. One of the most feared complications of this surgical technique is colon injury and the objective of this work is to evaluate the incidence of retrorenal colon (RRC) both supine and prone position, in pediatric patients, through radiological images.

MATERIALS AND METHOD

A retrosepctive review was performed of all abdominal CT scans performed in one center, in patients under 18 years since 2017 to 2019. The ideal path for percutaneous puncture was traced in the upper, middle, and lower calyces of both kidneys in the prone and supine positions and contact with the kidney and adjacent organs was evaluated, with a uro-radiologist. Chi-square test and Student's t test were applied.

RESULTS

50 CT-scans were performed on 44 children. Patients had a mean age of 12.6 years and 71.4% were male. Twenty-five scans were performed in the prone and 25 in the supine position. The incidence of RRC for the left kidney (LK) was significantly higher in the lower calyx in prone position than in the supine position, 28% vs 4% (p = 0.049), and the right kidney (RK) presented RRC only in the prone position. The liver was the most frequent retrorenal organ (97.7%) for the RK, with a non-significant difference by position, while for the LK the spleen was the most frequent (61.1%).

DISCUSSION

Colon injury is one of the most morbid complication in PCNL and one of the reasons to perform a CT scan before surgery, on which its incidence appears to be <1% in adults. The present study revealed RRC to be present in three (12%) patients in the supine position and seven (28%) patients in the prone position (p=0.15). These results were slightly higher from those reported in adults (supine: 1.7%-10%; prone: 6.8%-20%), but there are no reports in the literature on this issue to allow appropriate comparison. This is the first study to attempt to assess the incidence of RRC in children according to position.

CONCLUSION

The incidence of RRC for an ideal puncture was significantly higher in the lower calyx of the left kidney in the prone position than in the supine position, and in the right kidney, the RRC only occurred in the prone position.

International Alliance of Urolithiasis (IAU) Guideline on percutaneous nephrolithotomy

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

Electromagnetic-guided puncture: a tool or a tale?

PURPOSE OF REVIEW

The puncture technique and site of the puncture can impact the clinical outcome and the development of postoperative adverse events following percutaneous nephrolithotomy (PCNL). The aim of the current review was to discuss the available puncture guidance approaches and outline the potential role of the recently introduced electromagnetic-guided method.

RECENT FINDINGS

The puncture and PCNL tract establishment is usually performed using fluoroscopic or ultrasound guidance or a combination of two approaches. Electromagnetic-guided puncture is one of the most recent advancements of technology. The puncture navigation to the renal collecting system is available after placing a special wire with an electromagnetic tracking sensor into the desired calyx through the flexible ureterorenoscope. The available experimental and clinical studies have shown a high first puncture rate, decreased median time for obtaining a puncture, and shorter learning curves for beginners.

SUMMARY

Fluoroscopic and ultrasound guidance are the main approaches used by urologists. However, these modalities require a steep learning curve, approximately 60 cases for reaching competency. The initial data on electromagnetic navigation have shown the feasibility and potential promising outcomes of this novel approach. New studies are required to investigate its potential implementation opportunities in the daily practice of urologists.

Needle-perc-assisted endoscopic surgery for patients with complex renal stones: technique and outcomes

Our aim was to investigate the safety and efficacy of needle-perc-assisted percutaneous nephrolithotomy (PCNL) or retrograde intrarenal surgery (RIRS), namely, needle-perc-assisted endoscopic surgery (NAES), in a series of patients with large and/or complex renal stones. From May 2018 to August 2021, a total of 119 patients underwent NAES at our institute. Among them, 94 patients underwent needle-perc-assisted standard PCNL in prone position and 25 underwent needle-perc-assisted RIRS in the Galdakao-modified supine Valdivia position or prone split-leg position. Clinical factors including age, sex, medical history, and stone characteristics were collected. Intraoperative and postoperative outcomes were retrospectively evaluated. The patients' mean age ± standard deviation was 50.3 ± 14.3 years. The mean stone size was 7.6 ± 3.7 and 1.7 ± 0.8 cm for needle-perc-assisted PCNL and RIRS, respectively. Of the 119 patients, 51 had staghorn stones, 16 had solitary kidneys, 17 had a history of ipsilateral renal surgery, and 6 had calyceal diverticular stones. The mean operative time was 83.4 ± 25.9 min for needle-perc-assisted PCNL and 66.3 ± 21.8 min for needle-perc-assisted RIRS. The stone-free rate (SFR) for needle-perc-assisted PCNL was 77.7% after the first treatment and 88.3% after auxiliary treatments. The SFR for needle-perc-assisted RIRS was 88.0% and no auxiliary treatments were carried out in this group. Eleven (11.7%) patients who underwent needle-perc-assisted standard PCNL developed Clavien-Dindo grade I or II complications. Three (12.0%) patients who underwent needle-perc-assisted RIRS developed a fever (grade I). The overall complication rate for NAES was 11.8%, with no urosepsis, angioembolization, or other grade III to V complications. In conclusion, NAES is a safe and effective procedure for one-step complete resolution of large and/or complex renal stones with no additional procedure-related complications.

THE FUNCTIONAL STATE OF THE RENAL PARENCHYMA AFTER VARIOUS VIDEO ENDOSURGICAL METHODS OF TREATMENT OF PATIENTS WITH LARGE AND COMPLEX KIDNEY STONES

The work is based on the analysis of literature data devoted to the problem of preserving the functional state of the kidneys with various video endoscopic methods of surgical treatment of large and complex kidney stones. The purpose of the review is to highlight the likelihood of deterioration in the functional state of the kidneys in the postoperative period. A detailed analysis of postoperative outcomes in various minimally invasive methods of treatment of patients with large and complex kidney stones was carried out, with an overview of the possibility of using dynamic nephroscintigraphy as a method of objectively assessing the functional state of the kidneys.

Complications of renal interventions: a pictorial review of CT findings

A number of potential vascular and non-vascular complications can arise from surgical, extracorporeal shock wave lithotripsy, radiotherapy and radiological renal interventions, including percutaneous image-guided biopsy and drainage. Computed tomography scan is usually one of the first and most important diagnostic imaging examinations requested when a potential complication is suspected. There are a wide range of common and uncommon potential complications from renal interventions. An understanding of underlying risk factors is important to reduce potential complications from renal intervention. Radiologists play a crucial role in recognising and diagnosing post-renal intervention complications on computed tomography scans, which could significantly improve the patient’s prognosis.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Percutaneous Nephrolithotomy

CONTEXT

Although percutaneous nephrolithotomy (PCNL) has been performed for decades and has gone through many refinements, there are still concerns regarding its more widespread utilization because of the long learning curve and the potential risk of severe complications. Many technical details are not included in the guidelines because of their nature and research protocol.

OBJECTIVE

To achieve an expert consensus viewpoint on PCNL indications, preoperative patient preparation, surgical strategy, management and prevention of severe complications, postoperative management, and follow-up.

EVIDENCE ACQUISITION

An international panel of experts from the Urolithiasis Section of the European Association of Urology, International Alliance of Urolithiasis, and other urology associations was enrolled, and a prospectively conducted study, incorporating literature review, discussion on research gaps (RGs), and questionnaires and following data analysis, was performed to reach a consensus on PCNL.

EVIDENCE SYNTHESIS

The expert panel consisted of 36 specialists in PCNL from 20 countries all around the world. A consensus on PCNL was developed. The expert panel was not as large as expected, and the discussion on RGs did not bring in more supportive evidence in the present consensus.

CONCLUSIONS

Adequate preoperative preparation, especially elimination of urinary tract infection prior to PCNL, accurate puncture with guidance of fluoroscopy and/or ultrasonography or a combination, keeping a low intrarenal pressure, and shortening of operation time during PCNL are important technical requirements to ensure safety and efficiency in PCNL.

PATIENT SUMMARY

Percutaneous nephrolithotomy (PCNL) has been a well-established procedure for the management of upper urinary tract stones. However, according to an expert panel consensus, core technical aspects, as well as the urologist's experience, are critical to the safety and effectiveness of PCNL.

Comparison of antegrade and retrograde ureterolithotripsy for proximal ureteral stones: a systematic review and meta-analysis

Background

Antegrade percutaneous ureterolithotripsy (URSL) could be a treatment option for large and/or impacted proximal ureteral stones, which are difficult to treat. To review the current approach and treatment outcomes and to compare the efficacy of retrograde and antegrade URSL for large proximal ureteral stones, we evaluated the unique perspectives of both surgical modalities.

Methods

This systematic literature review and meta-analysis was performed in July 2020. Articles on human studies and treatment of ureteral stones with URSL were extracted from the PubMed, MEDLINE, Embase, Cochrane Library, Scopus, and the Japan Medical Abstracts Society databases without any language restrictions. The risks of bias for randomized controlled trials (RCTs) and non-randomized controlled trials (non-RCTs) were assessed using the Cochrane risk of tool and the Risk of Bias in Non-randomized Studies- of Interventions tool, respectively.

Results

A total of 10 studies, including seven RCTs and three non-RCTs, were selected for the analysis; 433 and 420 cases underwent retrograde and antegrade URSL, respectively. The stone-free rate (SFR) was significantly higher in antegrade URSL than in retrograde URSL (SFR ratio: 1.17, 95% CI: 1.12-1.22; P<0.001), while the hospital stay was significantly longer in antegrade URSL than in retrograde URSL (standardized mean difference: 2.56, 95% CI: 0.67-4.46; P=0.008). There were no significant differences in the operation time and the overall complication rate between the two approaches.

Conclusions

Despite the heterogeneity of data and bias limitations, this latest evidence reflects real practice data, which may be useful for decision making.

Tranexamic acid in patients with complex stones undergoing percutaneous nephrolithotomy: a randomised, double-blinded, placebo-controlled trial

OBJECTIVES

To assess the efficacy and safety of single-dose tranexamic acid on the blood transfusion rate and outcomes of patients with complex kidney stones undergoing percutaneous nephrolithotomy (PCNL).

PATIENTS AND METHODS

In a randomised, double-blinded, placebo-controlled trial, 192 patients with complex kidney stone (Guy's Stone Scores III-IV) were prospectively enrolled and randomised (1:1 ratio) to receive either one dose of tranexamic acid (1 g) or a placebo at the time of anaesthetic induction for PCNL. The primary outcome measure was the occurrence rate of perioperative blood transfusion. The secondary outcome measures included blood loss, operative time, stone-free rate (SFR), and complications. ClinicalTrials.gov identifier: NCT02966236.

RESULTS

The overall risk of receiving a blood transfusion was reduced in the tranexamic acid group (2.2% vs 10.4%; relative risk, 0.21, 95% confidence interval [CI] 0.03-0.76, P = 0.033; number-needed-to-treat: 12). Patients randomised to the tranexamic acid group had a higher immediate and 3-month SFR compared with those in the placebo group (29% vs 14.7%, odds ratio [OR] 2.37, 95% CI 1.15-4.87, P = 0.019, and 46.2% vs 28.1%, OR 2.20, 95% CI 1.20-4.02, P = 0.011, respectively). Faster haemoglobin recovery occurred in patients in the tranexamic acid group (mean, 21.3 days; P = 0.001). No statistical differences were found in operative time and complications between groups.

CONCLUSIONS

Tranexamic acid administration is safe and reduces the need for blood transfusion by five-times in patients with complex kidney stones undergoing PCNL. Moreover, tranexamic acid may contribute to better stone clearance rate and faster haemoglobin recovery without increasing complications. A single dose of tranexamic acid at the time of anaesthetic induction could be considered standard clinical practice for patients with complex kidney stones undergoing PCNL.

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.

Enhanced super-mini-PCNL (eSMP): low renal pelvic pressure and high stone removal efficiency in a prospective randomized controlled trial

OBJECTIVE

In the present prospective randomized controlled trial (RCT), enhanced-SMP (eSMP) and conventional Chinese mini-PCNL (mPCNL) were compared to test the low renal pelvic pressure (RPP) and high stone removal efficiency in eSMP.

MATERIALS AND METHODS

Hundred patients with 2-5 cm renal calculus were enrolled. Renal pelvic pressure, operation time, lithotripsy time, removed stone volume, and complications were compared between eSMP and mPCNL statistically.

RESULTS

There was no significant difference in removed stone volume between mPCNL and eSMP (8.09 ± 3.36 vs. 7.88 ± 3.07 mm³, t = 0.320, p = 0.750), lithotripsy time in mPCNL was longer than eSMP (49.6 ± 19.5 vs. 34.9 ± 14.2 min, t = 4.152, p < 0.001), thus stone removal efficiency was higher in eSMP (13.71 ± 1.18 vs. 9.82 ± 1.24 mm³/h, t = 15.499, p < 0.001). Intra-operative RPP in mPCNL was higher than eSMP (17.72 ± 3.33 vs. 12.03 ± 2.37 mmHg, t = 9.524, p < 0.001); accumulated time of backflow status (RPP > 30 mmHg) in mPCNL was longer than eSMP (23.3 ± 16.9 vs. 3.7 ± 4.2 s, t = 7.710, p < 0.001). There was no significant difference in postoperative fever rate between mPCNL and eSMP (12.77% vs. 4.34%, χ² = 2.095, p = 0.148), nor final stone-free rate (87.2% vs. 91.3%, χ² = 0.401, p = 0.526). Hospital stay in eSMP was shorter than mPCNL (2.54 ± 0.72 vs. 3.00 ± 0.88, t = 2.724, p = 0.008).

CONCLUSION

Enhanced SMP (eSMP) was safe and effective in the management of 2-5 cm renal calculus. It can keep a lower renal pelvic pressure and a higher stone removal efficiency when compared to conventional Chinese mini-PCNL.

CLINICAL TRIAL REGISTRATION

NC03206515.

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

Introduction

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

Material and methods

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

Results

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

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

Conclusions

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

A hypothetical method for calculation of the access point, direction angle and access angle for percutaneous nephrolithotomy

Urinary stone disease has an increasing prevalence across the globe, and endoscopic treatment modalities have replaced open surgery. Percutaneous nephrolithotomy (PCNL) is a successful, safe and reliable minimally invasive method in the treatment of renal stones, especially big (≥2 cm) or complex ones. Gaining access is the most critical step of this procedure, which can affect the rest of the operation. Although previously described techniques, eye of the needle and triangulation techniques, are being used for gaining access, urologists (especially novice ones) can still have problems during this step. Some navigation concepts have been developed in order to make the access safer, easier and more successful, however, none of them has been incorporated in daily routine practice till now because of either complicated techniques or requirement of sophisticated equipment. Our hypothesis is that the access point, direction angle and access angle in order to touch a stone during PCNL can be calculated by the data obtained from the computed tomography images with the help of mathematical formulations, namely the theorem of the cosine.

Prone percutaneous nephrolithotomy: its advantages and our technique for puncture

Percutaneous nephrolithotomy (PCNL) is considered the treatment of choice for large urinary calculi and staghorn lithiasis. The approach for this surgery may be either supine or prone, and different access techniques are described in the literature with the use of ultrasound, fluoroscopy, or both combined. We believe that prone PCNL offers to the urologist key advantages, such as the possibility of puncturing anatomically abnormal urinary tracts, to perform multiple percutaneous tracts in the same kidney, experiencing the vacuum cleaner effect, ease of exploring the upper calyx through the inferior calyx, possibility to perform endoscopic combined intrarenal surgery (ECIRS) and bilateral simultaneous surgery, and to performed over local anesthesia. An adequate training for the endourologist should include both the prone and supine techniques for PCNL and to know which patient can benefit the most from each one.

Current trends of percutaneous nephrolithotomy in a developing country

Introduction

To present the current practice patterns on percutaneous nephrolithotomy (PCNL) in a developing country.

Materials and Methods

A survey was offered to Brazilian urologists during the II International Endourology Symposium held in Sao Paulo, in 2015. The first seven questions were related to demographic data while the 20 remaining were directed to urologists who performed PCNL.

Results

From 250 participants, 100 replied to the survey, 81% performed PCNL and 60.4% of performers had been in practice for less than 15 years. Eighty-one percent were trained in the prone position and 64% in supine. PCNL was learned during the residency in 66.7% and 2.5% had fellowship training. Prone position was the preferred decubitus for simple or complex calculi, though for obese patients there was no difference. Younger surgeons prefer supine while older surgeons prefer prone. The access was obtained by the surgeon in all cases, 96.3% use fluoroscopy and 3.7% prefer ultrasonography. Forty-seven percent use ultrasonic lithotripters and 4.1% laser. For kidney drainage, 71.6% place a nephrostomy tube. Double J stent is left in 77%. The postoperative image method was CT for 50%. Colonic injury was reported by 25%, predominantly in the senior group without statistically difference between positions.

Conclusions

From a selected group of urologists, we observe that Brazilian urologists usually gain their own access for PCNL guided by fluoroscopy. They predominantly prefer the prone position, use fascial dilators, ultrasonic lithotripters and place a nephrostomy tube when exiting the kidney. Fellowship programs, ultrasonography, flexible nephoscopy and tubeless procedures could be encouraged.

Fluoroscopy-free ultrasonography-guided percutaneous nephrolithotomy in pediatric patients: a single-center experience

OBJECTIVES

To present the safety and efficacy of fluoroscopy-free ultrasound-guided PCNL for the treatment of renal calculi in pediatric patients of all ages.

METHODS

30 children with mean age of 5 years (6 months-12 years) underwent totally ultrasound-guided PCNL from March 2013 to August 2016. The pyelocalyceal system was punctured in prone position using only ultrasonography guidance, and the tract was dilated using a single shot dilation technique. No fluoroscopy was used during any of the stages of renal access. The procedure was performed using adult-sized instruments.

RESULTS

The mean stone size was 27.1 ± 8.7 mm. Mean access time was 4.3 ± 2 min. Mean nephroscopic time was 34.6 ± 15.2 min. Mean hospital stay of patients was 3 days (range 2-5). 21 patients were stone-free after the procedure (70% success rate). Only four patients out of 30 experienced postoperative complications.

CONCLUSIONS

The results of this study showed that fluoroscopic-free ultrasound-guided PCNL in pediatric patients of all ages is safe, highly efficient, and minimizes potential radiation exposure risks associated with the procedure.

Comparative study of the treatment of 20-30 mm renal stones with miniaturized percutaneous nephrolithotomy and flexible ureterorenoscopy in obese patients

PURPOSE

To evaluate and compare flexible ureteroscopy (f-URS) and mini-percutaneous nephrolithotomy (mPNL) for 20-30 mm renal stones in obese patients regarding efficacy and safety.

METHODS

Between May 2011 and June 2017, 254 obese patients who had 20-30 mm kidney stone were consecutively included in the study; 106 patients underwent mPNL and 148 underwent f-URS by the same surgeon. The following parameters were retrospectively assessed: patient and stone characteristics, surgical details, perioperative outcomes, and stone-free rates (SFR).

RESULTS

F-URS group was similar to mPNL group in terms of the mean duration of surgery (92.8 ± 26.1 vs 87.4 ± 31.5 min, P = 0.137) and the final SFR (89.1 vs 92.5%, P = 0.381). The f-URS group had significantly shorter postoperative stay (1.0 ± 0.8 vs 4.3 ± 1.7 days, P < 0.001) and lower postoperative complications (11.5 vs 26.4%, P = 0.002). However, the f-URS group had a lower SFR after first session (67.2 vs 87.4%, P < 0.001) and needed more number of procedures (1.5 ± 0.4 vs 1.3 ± 0.4, P < 0.001) than the mPNL group.

CONCLUSIONS

MPNL has a higher efficacy (higher SFR after first session and lower number of procedures); however, f-URS offers advantages regarding safety (lower complication rate). Therefore, both options can be offered to obese patients with renal stones from 20 to 30 mm in size. Nevertheless, these results must be confirmed by further prospective randomized trials.

Role of Minimally Invasive (Micro and Ultra-mini) PCNL for Adult Urinary Stone Disease in the Modern Era: Evidence from a Systematic Review

Purpose of Review

The role of PCNL and the expertise surrounding it has expanded in recent decades. Miniaturisation of equipment and instrument size has formed a part of this innovation. Although an increasing number of studies have been performed on miniaturised PCNL (Mi-PCNL) recently, a critical appraisal on these is lacking. We therefore conducted a systematic review of the literature to evaluate the efficacy, safety and feasibility of Mi-PCNL techniques (< 15 Fr).

Recent Findings

A systematic review was conducted from 1990 to March 2017 on outcomes of Mi-PCNL [micro PCNL (m-PCNL) and ultra-mini PCNL (UMP)] in adult patients. Ten studies (three on m-PCNL and seven on UMP) were included in our study. Across the three studies, 118 patients (mean age 42.2 years, male to female ratio 1.3:1) underwent m-PCNL (4.8 Fr). For a mean stone size of 13.9 mm, a mean stone-free rate (SFR) was 89% and an overall complication rate was 15.2% [Clavien classification I (44%), II (28%), III (28%)], with no Clavien IV or V complications. Across the seven studies, 262 patients (mean age 49.4 years, male to female ratio 1.5:1) underwent UMP (13–14 Fr). For a mean stone size of 18.6 mm, a mean SFR was 88.3% and an overall complication rate was 6.2% [Clavien classification I (57%), II (36%), III (7%)], with no Clavien IV or V complications. While the transfusion rates for m-PCNL was 0.85%, only one case each in m-PCNL and UMP needed conversion to mini PCNL.

Summary

Our review shows that for small- to medium-sized renal stones, Mi-PCNL can yield good stone-free rates whilst maintaining a low morbidity associated with it. There were no Clavien > III complications and no mortality with only one transfusion reported from this minimally invasive technique.

Percutaneous nephrolithotomy: complications and how to deal with them

Percutaneous nephrolithotomy is a common surgical treatment for large and complex stones within the intrarenal collecting system. A wide variety of complications can result from this procedure, including bleeding, injury to surrounding structures, infection, positioning-related injuries, thromboembolic disease, and even death. Knowledge of the different types of complications can be useful in order to prevent, diagnose, and treat these problems if they occur. This review describes the diversity of complications with the goal of improving their avoidance and treatment.

Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes

Objective

To evaluate the predictive value of the distance from skin to calyx (SCD) on the outcome and complication rates of patients undergoing mPNL.

Materials and Methods

Patient’s charts, who had undergone mPNL between June 2012 and June 2015, were analyzed retrospectively. Patients who had a preoperative computerized tomography (CT) were enrolled into the study. Two separateurologists evaluated the CT scans and calculated the SCD defined as the distance between the skin and surface/lateral edge of the calyx, which was the preferred site of entry for percutaneous access. The average value of the two measurements was included inthe final analysis to avoid bias. The mean SCD was 75mm. According to the median SCD value, patients were divided into two groups: group 1 (SCD ≤75) and group 2 (SCD >75).

Results

A total of 140 patients and 130 patients were enrolled in groups 1 and 2, respectively. The mean operation time and the mean fluoroscopy time was significantly longer in group 2 (p:0.004 vs. p:0.021). The rate of blood transfusion was significantly higher in group 1 (6 patients). None of patientsin group 2required blood transfusion (p:0.017). Stone-free status after a single session of mPNL was 67.1% in group 1 and 75.4% in group 2 (p:0.112). After additional procedures, stone-free rates increased to 84.3% and 85.4% in group 1 and group 2, respectively (p:0.802).

Conclusion

Our study demonstrated that longer SCD was not a predictive factor for stone-free rates after mPNL. However, SCD over 75mm was associated with longer operation time and fluoroscopy time with lower rates of transfusion.

A new era of Asian urology: a SWOT analysis

Economic prosperity and increasing connectivity have made Asia an emerging centre of growth in health care, including in the field of urology. Large and varied patient populations, the availability of a trained workforce, the use of English as a common communication language, and overall low costs have contributed to this change. Rapid growth of regional urological associations and journals has fuelled the aspirations and abilities of Asian urologists to not only keep abreast of but often lead the change in urological disease management. Asian urology has immense potential to expand in areas in which it currently lags behind, the most important being research. The increasing ability to travel aids in developing networks for collaboration. However, Asian urologists will need to look at sustainable models of engagement and temper the need for short-term results if these opportunities are to reach their maximal potential.

Comparison of minimally invasive percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of intermediate proximal ureteral and renal stones in the elderly

The aim of this study is to compare the outcomes of flexible ureteroscopy (fURS) and minimally invasive percutaneous nephrolithotomy (mPNL) for the treatment of renal and/or proximal ureteral stones sized 1-2 cm in the elderly (≥60 years). Between January 2010 and March 2015, 184 consecutive mPNL and fURS were performed to treat intermediate renal and/or proximal ureteral stones in geriatric patients. The records were retrospectively reviewed and outcomes were compared. Although no significant difference was found in the complication rate between two groups, a statistical trend (p = 0.059) in favor of fURS was observed. In addition, multivariate analysis demonstrated that mPNL, preoperative positive urine culture and lower hemoglobin were independent risk factors for postoperative complication (p = 0.016, p = 0.021, p = 0.001, respectively). And fURS was significantly associated with less hemoglobin drop, red blood cell transfusion, analgesics requirement, postoperative hospital duration, and charges of laboratory tests, medical examinations and medications (p = 0.019, p = 0.037, p = 0.006, p = 0.000 and p = 0.007, p = 0.000, p = 0.000, p = 0.001, respectively), while higher costs of operations (p = 0.008). Receiver operating characteristic curve suggested a preoperative hemoglobin of 106.5 g/L as the threshold for predicting red blood cell transfusion after mPNL. The overall one-session stone-free rate of fURS at 1 month was lower (p = 0.006), while it was similar for solitary stone between two groups. Comorbidity and previous stone surgery did not affect postoperative complication and stone-free rate. This study shows that mPNL is more effective for multiple stones, but fURS is associated with potentially less complications and postoperative hospital stay. Furthermore, preoperative hemoglobin level and urine culture can be used to predict postoperative complication risk and they may be helpful in choosing treatment methods for the elderly.

Positioning for percutaneous nephrolithotomy

PURPOSE OF THE REVIEW

To highlight the progressive evolution of the issue of patient positioning for percutaneous nephrolithotomy (PNL), explain the history of the prone and supine positions, report respective advantages and drawbacks, critically interpret the past and current literature supporting such arguments, identify the best candidates for each position, and reflect on the future evolution of the two approaches.

RECENT FINDINGS

Positioning for PNL has become a matter of debate during the last decade. The traditional prone PNL position - most widely performed with good success and few complications, and exhibiting essentially no limits except for the treatment of pelvic kidneys - is nowadays flanked mainly by the supine and supine-modified positions, equally effective and probably safer from an anesthesiological point of view. Of course, both approaches have a number of advantages and drawbacks, accurately reported and critically sieved.

SUMMARY

The current challenge for endourologists is to be able to perform PNL in both prone and supine positions to perfectly tailor the procedure on any patient with any stone burden, including increasingly challenging cases and medically high-risk patients, according to the patient's best interest. Intensive training and experience is especially needed for supine PNL, still less popular and underperformed worldwide.

VIDEO ABSTRACT

http://links.lww.com/COU/A8.

[Flexible ureterorenoscopy vs percutaneous nephrolithotomy for renal stone management: Retrospective study]

PURPOSE

The aim of this study was to evaluate the efficacy and tolerance of renal stone fragmentation by flexible ureterorenoscopy (URS), compared to percutaneous nephrolithotomy (PCNL).

MATERIAL AND METHODS

Patients treated between 1998 and 2010 by URS and PCNL for intrarenal stone were reviewed. Patients' and stones' characteristics were analyzed. The preoperative parameters were reported as well as the procedure's efficiency and its complications. Success was defined by the absence of residual lithiasis visualized on renal imaging at 6 months of follow-up.

RESULTS

Among 531 patients included, there were 159 PCNL and 372 URS. The mean duration of hospitalization after PCNL was 8±4.6 days and 3±1.7 days after URS. The mean stones' size was higher in the PCNL group (19.9±7.5mm) than for the URS group (9.7±5.6mm; P<0.0001). The stone-free rate was significantly better in the PCNL group for stones measuring between 10 and 20mm (P<0.0001) and for stones of more than 20mm (P=0.017). Postoperative complications were significantly more frequent (27 %) and more severe (8.8 % vs Clavien III and IV) in the PCNL, than in the URS group, respectively (P=0.0001).

CONCLUSION

PCNL is a successful technique for renal stone fragmentation. However, URS seemed more tolerated despite a lower stone-free rate.

LEVEL OF EVIDENCE

4.

The effects of previous open renal stone surgery types on PNL outcomes

INTRODUCTION

Our aim was to demonstrate the effect of insicion of renal parenchyma during open renal stone surgery (ORSS) on percutaneous nephrolithotomy (PNL) outcomes.

METHODS

Patients with history of ORSS who underwent PNL operation between June 2005 and June 2015 were analyzed retrospectively. Patients were divided into two groups according to their type of previous ORSS. Patients who had a history of ORSS with parenchymal insicion, such as radial nephrotomies, anatrophic nephrolithotomy, lower pole resection, and partial nephrectomy, were included in Group 1. Other patients with a history of open pyelolithotomy were enrolled in Group 2. Preoperative characteristics, perioperative data, stone-free status, and complications were compared between the groups. Stone-free status was defined as complete clearance of stone(s) or presence of residual fragments smaller than 4 mm. The retrospective nature of our study, different experience level of surgeons, and lack of the evaluation of anesthetic agents and cost of procedures were limitations of our study.

RESULTS

123 and 111 patients were enrolled in Groups 1 and 2, respectively. Preoperative characteristics were similar between groups. In Group 1, the mean operative time was statistically longer than in Group 2 (p=0.013). Stone-free status was significantly higher in Group 2 than in Group 1 (p=0.027). Complication rates were similar between groups. Hemorrhage requiring blood transfusion was the most common complication in both groups (10.5% vs. 9.9%).

CONCLUSIONS

Our study demonstrated that a history of previous ORSS with parenchymal insicion significantly reduces the success rates of PNL procedure.

Advances in urology 2014–2015

It has become customary that a session is held at the British Association of Urological Surgeons (BAUS) annual meeting, wherein the most important advances in the major urological sub-specialities are summarised by British opinion leaders for the benefit of the core of urologists. It gives us pleasure to present in this paper the topics covered at the BAUS meeting in June 2015, in Manchester, UK.