International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management.

BACKGROUND: The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis. PURPOSE: To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones. METHODS: A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion. RESULTS: The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document. CONCLUSION: A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

Tubeless mini-percutaneous nephrolithotomy for renal stones larger than 20 mm.

INTRODUCTION: The aim of this study is to evaluate the outcomes of tubeless mini- percutaneous nephrolithotomy (PCNL) for the treatment of large (>20 mm) renal stones. PATIENTS AND METHODS: This study included consecutive patients who underwent single-session tubeless mini-PCNL (tract size 16-20 F) for large (>20 mm) renal stones. Stone-free status meant complete clearance or residual fragments <4 mm. Complications were recorded and classified according to modified Clavien-Dindo classifications. Risk variables for significant residuals were determined with univariate (Chi-square and t-test) and multivariate logistic regression analyses. RESULTS: Between July 2015 and November 2018, 225 patients were included. The mean age was 42.9 years; the mean stone size was 30.2 ± 9.6 mm and 75% of patients were males. A single renal stone was present in 54 patients (24%), multiple stones in 108 (48%), and staghorn stones in 63 (28%). The stone-free rate was 87.6%. The complication rate was 8.4% (Grade I-II in 7.5%, III in 0.9%). Three patients (1.3%) required blood transfusion. Independent risk factor for significant residual fragments was the presence of stones in multiple sites inside the pelvicalyceal system (relative risk: 13.44, 95% confidence interval: 1.78-101.43, P = 0.012). CONCLUSIONS: Mini-PCNL is an effective and safe treatment option for patients with large renal stones (>20 mm). Stones located in multiple sites is the only predictor of significant residual stones.

Cross-continental comparison of safety and protection measures amongst urologists during COVID-19.

OBJECTIVES: To determine the well-being of urologists worldwide during the coronavirus disease 2019 pandemic, and whether they have adequate personal protective equipment knowledge and supplies appropriate to their clinical setting. METHODS: Urologists worldwide completed a Société Internationale d'Urologie online survey from 16 April 2020 until 1 May 2020. Analysis was carried out to evaluate their knowledge about protecting themselves and others in the workplace, including their confidence in their ability to remain safe at work, and any regional differences. RESULTS: There were 3488 respondents from 109 countries. Urologists who stated they were moderately comfortable that their work environment offers good protection against coronavirus disease 2019 showed a total mean satisfaction level of 5.99 (on a "0 = not at all" to "10 = very" scale). A large majority (86.33%) were confident about protecting themselves from coronavirus disease 2019 at work. However, only about one-third reported their institution provided the required personal protective equipment (35.78%), and nearly half indicated their hospital has or had limited personal protective equipment availability (48.08%). Worldwide, a large majority of respondents answered affirmatively for testing the healthcare team (83.09%). Approximately half of the respondents (52.85%) across all regions indicated that all surgical team members face an equal risk of contracting coronavirus disease 2019 (52.85%). Nearly one-third of respondents reported that they had experienced social avoidance (28.97%). CONCLUSIONS: Our results show that urologists lack up-to-date knowledge of preferred protocols for personal protective equipment selection and use, social distancing, and coronavirus disease 2019 testing. These data can provide insights into functional domains from which other specialties could also benefit.

Super-mini percutaneous nephrolithotomy (SMP): a new concept in technique and instrumentation.

OBJECTIVE: To present a novel miniature endoscopic system designed to improve the safety and efficacy of percutaneous nephrolithotomy, named the 'super-mini percutaneous nephrolithotomy' (SMP). PATIENTS AND METHODS: The endoscopic system consists of a 7-F nephroscope with enhanced irrigation and a modified 10-14 F access sheath with a suction-evacuation function. This system was tested in patients with renal stones of <2.5 cm, in a multicentre prospective non-randomised clinical trial. In all, 146 patients were accrued in 14 centres. Nephrostomy tract dilatation was carried out to 10-14 F. The lithotripsy was performed using either a Holmium laser or pneumatic lithotripter. A nephrostomy tube or JJ stent was placed only if clinically indicated. RESULTS: SMP was completed successfully in 141 of 146 patients. Five patients required conversion to larger nephrostomy tracts. The mean (sd) stone size was 2.2 (0.6) cm and the mean operative duration was 45.6 min. The initial stone-free rate (SFR) was 90.1%. The SFR at the 3-month follow-up was 95.8%. Three patients required auxiliary procedures for residual stones. Complications occurred in 12.8% of the patients, all of which were Clavien grade ≤II and no transfusions were needed. In all, 72.3% of the patients did not require any kind of catheter, while 19.8% had JJ stents and 5.7% had nephrostomy tubes placed. The mean hospital stay was 2.1 days. CONCLUSIONS: SMP is a safe and effective treatment for renal stones of <2.5 cm. SMP may be particularly suitable for patients with lower pole stones and stones that ae not amenable to retrograde intrarenal surgery.

Failure of initial renal arterial embolization for severe post-percutaneous nephrolithotomy hemorrhage: a multicenter study of risk factors.

PURPOSE: Severe hemorrhage after percutaneous nephrolithotomy is a rare but alarming event. If local tamponade fails to control bleeding, the current treatment of choice is superselective renal arterial embolization. If initial embolization is unsuccessful, repeat embolization or nephrectomy is often required. To our knowledge we report the first study of risk factors for failed initial superselective renal arterial embolization. MATERIALS AND METHODS: We retrospectively reviewed the records of 17,619 patients who underwent a total of 19,185 percutaneous nephrolithotomies from January 2007 to April 2012 at 6 centers. Study inclusion criteria were percutaneous nephrolithotomy and severe postoperative renal hemorrhage requiring superselective renal arterial embolization. Data on patients in whom initial embolization failed were compared to those on patients with successful embolization on univariate and multivariate analysis. RESULTS: Of the 17,619 patients 117 (0.6%), met study inclusion criteria, including 90 males and 27 females. Initial treatment failed in 12 patients (10.3%), 8 underwent repeat superselective renal arterial embolization, 3 required 3 embolizations and 1 underwent nephrectomy. Complete bleeding cessation was achieved in all 11 repeat embolization cases. We identified 3 risk factors for failure of initial superselective renal arterial embolization, including multiple percutaneous access sites, more than 2 bleeding sites identified on renal angiogram and gelatin sponge alone used as the embolic material. CONCLUSIONS: Carefully selecting patients for multitract percutaneous nephrolithotomy, making an extra effort to identify all bleeding vessels during angiography and not using gelatin sponge as the only embolic material could potentially decrease the risk of failure of initial superselective renal arterial embolization after percutaneous nephrolithotomy.

Propensity score-matched analysis comparing retrograde intrarenal surgery with percutaneous nephrolithotomy in anomalous kidneys.

BACKGROUND: Endourologic interventions for urolithiasis in patients with anomalous kidneys can be challenging, and comparisons between these interventions are not well studied. We aim to compare the safety, outcomes and complications of retrograde intrarenal surgery (RIRS) versus percutaneous nephrolithotomy (PCNL) in patients with urolithiasis in anomalous kidneys. METHODS: A propensity score-matched pair analysis (PSM) was performed on pooled patient data from 20 centers. 569 patients with anomalous kidneys (horseshoe kidney [HSK], ectopic kidney, malrotated kidney) and urolithiasis who received either PCNL or RIRS as the primary modality of intervention from 2010 to 2020 were analyzed. Patients were matched based on calculated propensity scores by a regression model using age, sex, comorbidities, stone size, and renal anomaly type as co-variates. Multivariate logistic regression of factors (mode of treatment [PCNL or RIRS], comorbidities, stone size) and their effects on outcomes of stone-free rate (SFR), need to abandon surgery due to intraoperative difficulty, postoperative hematuria and sepsis and were analyzed when applicable. RESULTS: After PSM, there were a total of 127 pairs in each group. Overall, PCNL conferred a higher SFR compared to RIRS (OR=3.69, 95% CI 1.91-7.46, P<0.001), particularly in HSK (OR=3.33, 95% CI 1.22-9.99, P=0.023), and ectopic kidneys (OR=18.10, 95% CI 3.62-147.63, P=0.002), with no significant difference in malrotated kidneys. There was no significant difference in postoperative sepsis observed. Surgery was abandoned more often in RIRS than PCNL (6.3% vs. 0%, P=0.014). Although PSM provides a robust analysis due to baseline differences in the unmatched cohorts, this study was limited by an inevitable degree of selection bias. CONCLUSIONS: While both modalities are safe and efficacious, PCNL yields better SFR than RIRS in patients with anomalous kidneys, with no difference in postoperative sepsis rates. Patients may benefit from personalized management best carried out in high volume endourology centers.

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.

Definition and Unfavorable Risk Factors of Trifecta in Mini-Percutaneous Nephrolithotomy.

Objectives: In performing mini-percutaneous nephrolithotomy (PCNL), we aimed at achieving the trifecta of stone-free status and no complications in a single treatment session. We analyzed our experience to determine negative predictors for achieving these three-fold goals. Patients and Methods: The data of all consecutive patients who underwent tubeless mini-PCNL between July 2015 and March 2020 in two hospitals were retrospectively reviewed. Stone-free was defined as no residual stones. Complications were recorded and graded according to modified Clavien classification. Patients were divided into two groups according to the outcome (trifecta and non-trifecta). Factors affecting the outcome were compared between both groups by using univariate and multivariate analyses to detect independent unfavorable risk factors. Results: The study included 944 patients with mean age 40.2 years (standard deviation: 13.6). The stone-free rate after one session of mini-PCNL was 90.7%. Auxiliary procedures were needed in 14 patients (1.5%). Complications were observed in 76 patients (8.1%). Trifecta was achieved in 792 patients (84%). Independent unfavorable risk factors in multivariate analysis were number of caliceal groups affected by the stones (relative risks were 1.95 to 2.27 and 5.7 for one, two, and three caliceal groups respectively) and number of percutaneous tracts (relative risk was 2.2). Stone size and complexity were not significant predictors of missing trifecta in multivariate analysis. Conclusions: Mini-PCNL can achieve a high rate of trifecta (84%) for different stone sizes and complexities. Stones distribution in multiple caliceal groups and multiple tracts are the independent unfavorable risk factor.

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.

Safety and efficacy of a single middle calyx access (MCA) in mini-PCNL.

To compare outcomes of a single middle calyx access (MCA) with a single upper or lower calyceal access in mini-PCNL. From May 2015 through August 2018, patients' files who underwent a single renal access mini-PCNL were retrospectively reviewed. All patients underwent fluoroscopic-guided access (16-20 F) in the prone position. They were categorized into group 1 (MCA) and group 2 (either upper or lower calyceal access). Compared preoperative items included stone location, size, number and complexity (according to Guy's score). The compared outcome parameters were complication and stone-free rates. The study comprised 512 consecutive patients, 374 patients in group 1 and 138 in group 2. A single MCA was utilized to access 95% of proximal ureteral calculi, 89% for ureteropelvic junction stones, and 84% for stones present in the pelvicalyceal system and ureter. MCA was used in 89% of complete staghorn stones and 73% of multiple stones. the Stone-free rates (93% vs 90.6%, P = 0.350) and the complications rates (8% vs 7.2%, P = 0.772) were comparable between group 1 and 2 despite that MCA was used for most cases with complex stones. Complications severity were also comparable (P = 0.579). Mini-PCNL performed through a single MCA is effective and safe. This access can be used for the treatment of renal and upper ureteral calculi of different complexities and locations.

Mini vs standard percutaneous nephrolithotomy for renal stones: a comparative study.

To compare the outcome of mini-percutaneous nephrolithotomy (Mini-PNL) versus standard-PNL for renal stones. Retrospective study was performed between March 2010 and May 2013 for patients treated by Mini-PNL or standard-PNL through 18 and 30 Fr tracts, respectively, using pneumatic lithotripsy. Semirigid ureteroscope (8.5/11.5 Fr) was used for Mini-PNL and 24 Fr nephroscope for standard-PNL. Both groups were compared in stone free rate(SFR), complications and operative time using Student-t, Mann-Whitney, Chi square or Fisher's exact tests as appropriate in addition to logistic regression analysis. P < 0.05 was considered statistically significant. Mini-PNL (378) and standard-PNL (151) were nearly comparable in patients and stones criteria including stone burden (3.77 ± 2.21 vs 3.77 ± 2.43 cm2; respectively). There was no significant difference in number of tracts or supracostal puncture. Mini-PNL had longer operative time (68.6 ± 29.09 vs 60.49 ± 11.38 min; p = 0.434), significantly shorter hospital stay (2.43 ± 1.46 vs 4.29 ± 1.28 days) and significantly higher rate of tubeless PNL (75.1 vs 4.6%). Complications were significantly higher in standard-PNL (7.9 vs 20.5%; p < 0.001). SFR was significantly lower in Mini-PNL (89.9 vs 96%; p = 0.022). This significant difference was found with multiple stones and large stone burden (> 2 cm2), but the SFR was comparable between both groups with single stone or stone burden ≤ 2 cm. Logistic regression analysis confirmed significantly higher complications and SFR with standard-PNL but with significantly shorter operative time. Mini-PNL has significantly lower SFR when compared to standard-PNL (but clinically comparable) with markedly reduced complications and hospital stay. Most of cases can be performed tubeless. The significant difference in SFR was found with multiple stones or large stone burden (> 2 cm2), but not with single stones or stone burden ≤ 2 cm2.

Bilateral Single-session vs Staged Mini-percutaneous Nephrolithotomy for Renal Stones: A Comparative Study.

OBJECTIVE: To compare safety and efficacy of bilateral single-session mini-percutaneous nephrolithotomy (BSS-Mini-PNL) vs staged-Mini-PNL. PATIENTS AND METHODS: Adult patients with bilateral renal stones indicated for PNL were managed with BSS-Mini-PNL (45 patients and 90 renal units) and prospectively compared vs staged-Mini-PNL (55 patients and 110 renal units) between July 2014 and December 2017. Mini-PNL was done through 18-Fr tract in prone position under regional anesthesia and fluoroscopy using pneumatic lithotripsy. A semirigid ureteroscope (8.5/11.5 Fr) was used. Mann-Whitney, Student t, chi-square, or Fisher's exact tests were used as appropriate. RESULTS: Both groups were comparable in characteristics of stones and patients. Stone burden was 3.36 ± 1.61 vs 3.38 ± 1.18 cm2 in BSS-Mini-PNL vs staged-Mini-PNL, respectively. Staghorn stones were present in 13.3% vs 8.2% in BSS-Mini-PNL vs staged-Mini-PNL, respectively. There was no significant difference in the number of required tracts (1.34 ± 0.6 vs 1.25 ± 0.51 tract/renal unit) as well as the rate of tubeless Mini-PNL (81.1% vs 85.5%) or stone-free rate (90% vs 92.7%) in BSS-Mini-PNL vs staged-Mini-PNL, respectively. BSS-Mini-PNL had significantly shorter operative time (126.22 ± 37.2 vs 169.63 ± 61.28 minutes), shorter hospital stay (2 [1-8] vs 4 [2-16] days) and higher hemoglobin loss (1.1 [0.1-2.8] vs 0.5 [0.1-2.17] gm/d) than staged-Mini-PNL. The complications profile (17.8% vs 13.6%) and rate of blood transfusion (4.4% vs 3.6%) were comparable in BSS-Mini-PNL vs staged-Mini-PNL, respectively, without significant difference. CONCLUSION: BSS-Mini-PNL is comparable to staged-PNL as regard stone-free rate and complications according to the selection criteria of the present study. However, BSS-Mini-PNL is associated with significant reduction in the cumulative operative time and hospital stay, which are reflected on the overall cost.

Mini-percutaneous nephrolithotomy for stones in anomalous-kidneys: a prospective study.

To evaluate safety and efficacy of minipercutaneous nephrolithotomy (Mini-PNL) in management of stones in different types of renal anomalies. Patients with stones ≥2 cm or SWL-resistant stones in anomalous-kidneys treated by Mini-PNL between March 2010 and September 2012 were included prospectively. Mini-PNL was done under regional anesthesia in prone position with fluoroscopic guidance through 18 Fr sheath using semirigid ureteroscope (8.5/11.5 Fr) and pneumatic lithotripter. All patients were followed-up for 2-3 years. Stone-free rate was defined as absence of residual fragments ≥2 mm. Student-T, Mann-Whitney, Chi square (χ 2), Fisher-exact, one way ANOVA or Kruskal-Wallis test were used for analysis. Mini-PNL was performed for 59 patients (20 horseshoe, 15 malrotated, 7 polycystic, 13 duplex and 4 ectopic pelvic-kidneys). Mean age was 40.18 ± 12.75 (14-78) years. Mean stone burden was 31.72 ± 21.43 (7.85-141.3) mm2. Two tracts were required in 7 (11.9 %) patients. Tubeless Mini-PNL with double-J insertion was performed in all patients except two. Operative time was 50.17 ± 18.73 (15-105) min. Hemoglobin loss was 0.44 ± 0.30 (0-1.4) g/dL. Complications were reported in 15 (25.4 %) patients. No pleural injury, sepsis, perinephric-collection or renal-pelvis perforation were reported. Stone-free rate was 89.8 % (converted to open-surgery in one patient, second-look PNL in two patients, auxiliary SWL in three patients). Stone-free rate improved to 98.3 % after retreatment and auxiliary SWL. Site of puncture was mostly upper calyceal in horseshoe-kidney (80 %), mid calyceal in polycystic-kidney (85.7 %) and lower calyceal in duplex-kidney (46.2 %). Punctures were also significantly infracostal in horseshoe-kidney (100 %) and supracostal in both duplex (53.8 %) and malrotated-kidneys (66.7 %). Mini-PNL is safe for management of stones in anomalous-kidney with SFR comparable to standard-PNL but with less complications.