Percutaneous Nephrolithotomy Research Articles

Applications of flexible ureteroscope lithotripsy with negative pressure suction and percutaneous nephrolithotomy in the treatment of 2–3 cm diameter renal calculi

Applications of flexible ureteroscope lithotripsy with negative pressure suction and percutaneous nephrolithotomy in the treatment of 2–3 cm diameter renal calculi

Large Renal Calculus in a Patient With Crossed Fused Ectopic Kidney Managed With Percutaneous Nephrolithotomy: A Case Report

Large Renal Calculus in a Patient With Crossed Fused Ectopic Kidney Managed With Percutaneous Nephrolithotomy: A Case Report

No ureteral catheter mini percutaneous nephrolithotomy (NUC-mPCNL) achieves enhanced recovery after surgery (ERAS)

Conventional mini percutaneous nephrolithotomy (mPCNL) typically necessitates the pre-operative placement of ureteral catheters. With the development of enhanced recovery after surgery (ERAS), we introduce a novel approach: no ureteral catheter mini percutaneous nephrolithotomy (NUC-mPCNL). To evaluate the efficacy and safety of this innovative procedure compared to mPCNL, we compared the total operative time, stone clearance rate (SCR), stone-free rate (SFR), and complications among patients undergoing either modality from January to September 2021. Our findings revealed a statistically significant reduction in the mean total operative time for the NUC-mPCNL group (42.6 ± 2.4 vs. 60.2 ± 3.4 min, p < 0.001). The SCR, SFR and CSFR were comparable between two groups (98.5% vs. 97.8%, 84.3% vs. 76.0%, 64.7% vs. 60.0%, p = 0.337, 0.295, 0.625). WBC rise, hemoglobin drop and neutrophil percentage rise were similar in both groups. The overall complication rate in the NUC-mPCNL group was lower; however, the difference was not statistically significant (Clavien I, II and III; 11 vs. 13, 1 vs. 2 and 1 vs. 1). Consequently, we conclude that NUC-mPCNL effectively shortens the operative time and holds potential for expedited postoperative recovery.

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.

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). 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. 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 > 2cm 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 > 14F 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. 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 > 2cm and age ≤ 50 years. [ https://www.crd.york.ac.uk/PROSPERO/ ], identifier PROSPERO (CRD42023467284).

Effectiveness and safety of percutaneous nephrolithotomy with 3D mixed-reality guidance for renal calculi removal.

Effectiveness and safety of percutaneous nephrolithotomy with 3D mixed-reality guidance for renal calculi removal.

Prospective Evaluation of Outcomes and Complications in Ultra-Mini-Percutaneous Nephrolithotomy for Pediatric Nephrolithiasis: A Three-Year Study

Objective: This prospective study aimed to evaluate the outcomes and complications of Ultra-Mini Percutaneous Nephrolithotomy (UM-PCNL) in pediatric patients with renal calculi over a three-year period (2021-2023). We assessed Stone-Free Rates (SFR), operative success and perioperative complications to determine the efficacy and safety of UM-PCNL in children. Methods: Seventy-eight pediatric patients (aged 1-17 years) underwent UM-PCNL for renal calculi larger than 10 mm. Preoperative imaging, including ultrasonography and computed tomography, was utilized to assess stone size and location. Surgical outcomes, including SFR, operative time and the need for second-look procedures, were evaluated. Complications were graded using the Clavien-Dindo classification. Statistical analysis was conducted using SPSS, with a significance threshold of p &lt; 0.05. Results: The mean stone size was 18.2 ± 5.4 mm and the overall SFR after a single UM-PCNL procedure was 78.2%. Clinical success (defined as either stone-free status or clinically insignificant residual fragments) was achieved in 89.7% of patients. The mean operative time was 67 ± 22 minutes. Second-look procedures were required in 11.5% of cases. The overall complication rate was 19.2%, with no major complications (Clavien grade III-V). Minor complications included transient fever (6.4%), hematuria (12.8%) and urinary leakage (5.1%). Conclusion: UM-PCNL is a safe and effective procedure for managing pediatric nephrolithiasis, offering high stone-free rates and low complication risks. The use of smaller instruments reduces renal trauma, bleeding and the need for blood transfusions. These findings support UM-PCNL as a first-line treatment option for larger renal stones in pediatric patients. Further studies with long-term follow-up are recommended to assess recurrence and long-term renal function outcomes.

The Effects of Lavender and Rosemary Extracts on Sore Throat and Hoarseness After Endotracheal Intubation in Patients Undergoing Percutaneous Nephrolithotomy: A Randomized Clinical Trial

PurposeThis study aimed to compare the effects of lavender and rosemary extracts on sore throat and hoarseness after endotracheal intubation in patients undergoing percutaneous nephrolithotomy. DesignRandomized clinical trial. MethodsThis study was conducted on 90 patients undergoing percutaneous nephrolithotomy at Bahonar Hospital in Kerman in 2021. The patients were selected by convenience sampling method and randomly assigned to three groups: lavender, rosemary, and control. After general anesthesia with endotracheal intubation, an anesthesiologist put sterile gauzes impregnated with 3 cc of rosemary and lavender extracts into patients’ throats in the intervention groups, while the control group received 3 cc of distilled water. After the surgery, the gauzes and tracheal tubes were removed and the patients were transferred to the postanesthesia care unit (PACU), their sore throat and hoarseness were measured and recorded during and 2 to 6 to 24 hours after recovery. A significance level of < .05 was considered. FindingsThe study results showed a significant difference in the severity of sore throat between the 3 groups 2, 6, and 24 hours after surgery; sore throat in the rosemary group and then in the lavender group was lower than that in the control group (P < .05). The results also indicated a significant difference in hoarseness intensity between the three groups 2 and 6 hours after surgery; hoarseness intensity in the rosemary and lavender groups was lower than that in the control group, but it was not different between 3 groups 24 hours after surgery (P < .05). ConclusionsRosemary and lavender extracts had a positive effect on sore throat and hoarseness. As these herbs cause no complications in patients and are available and inexpensive, further studies are necessary to confirm the use of these herbs during intubation.

Reply to Editorial Comment on “Comparative Outcomes of Day-Case Percutaneous Nephrolithotomy Versus Conventional Inpatient Surgery: A Systematic Review and Meta-Analysis”

Reply to Editorial Comment on “Comparative Outcomes of Day-Case Percutaneous Nephrolithotomy Versus Conventional Inpatient Surgery: A Systematic Review and Meta-Analysis”

Radiating for Two: Quantifying Radiation Exposure to Pregnant Urologists During Percutaneous Nephrolithotomy.

Current occupational recommendations limit fetal radiation dose to 1 mSv. With increased gender diversity in urology, understanding radiation exposure during pregnancy is crucial. The purpose of this study was to determine surgeon uterine radiation dose during percutaneous nephrolithotomy (PCNL) and compare effectiveness of several radiation reduction strategies in a cadaver model. Two cadavers were used to simulate the surgeon and patient in a PCNL model. An ion chamber was placed behind the surgeon's anterior uterine wall to measure radiation dose. Three radiation reduction methods were compared: pulsed fluoroscopy (1, 4, 8, 15, 30 pps), low-dose (LD) fluoroscopy, and surgeon shielding (none, 0.35, 0.50, 0.70 mm lead equivalents). The average radiation dose/second was recorded for 20 trials per combination. Assuming 5 minutes of fluoroscopy per PCNL, the number of cases required to exceed the fetal occupational limit was determined. Decreasing pulse frequency from 30 to 1 pps reduced dose by 96% (p<0.001). The LD setting decreased dose by 56% (p<0.001). A 0.35 mm lead apron resulted in a 94% dose reduction (p<0.001), and the 0.50 and 0.70 mm lead aprons further reduced dose by 12% and 47%, respectively. At conventional fluoroscopy settings of automatic exposure control and 30 pps, a surgeon could perform 12 PCNLs using no lead or 189 PCNLs using a 0.35 mm lead apron before reaching the 1 mSv limit. In addition to shielding, employing 1 pps with LD further decreased radiation exposure, allowing over 6000 cases to be performed with <1 mSv uterine radiation exposure. Within the limitations of this cadaver study, these data support that high volume pregnant surgeons employing active radiation reduction techniques such as pulsed, LD fluoroscopy and appropriate shielding can maintain surgical volume with relatively low risk. Fetal dosimeter use with monthly monitoring is still encouraged to confirm safety throughout pregnancy.

Preoperative Immersive Virtual Reality (iVR) Applied to Percutaneous Nephrolithotomy: A Prospective Randomized Clinical Study of Surgical Planning and Clinical Outcomes.

Percutaneous nephrolithotomy (PCNL) is the procedure of choice for the management of complex or large renal stones. A major challenge for the surgeon, however, is the need to assimilate the nearly 2000 static images from a CT scan into a functional mental image to enable surgical planning. Accordingly, we investigated the potential of immersive virtual reality (iVR) to enhance surgical planning and its impact on the outcomes among patients undergoing PCNL. Between 2019-2023, 175 patients undergoing PCNL were pre-operatively randomized into a CT-only group (N=89) or a CT+iVR group (N=86). CT scans were rendered into iVR models that allowed the surgeon not only to visualize and manipulate each patient's relevant anatomy, but also simulate the percutaneous approach to the proposed calyx. Post-operative CT scans were defined as absolute stone-free, <2mm remnants or 2.1-4mm remnants. Pre-operative visualization of the iVR model resulted in a changed calyx of entry in 30% of cases. The CT+iVR group had a significant improvement in absolute stone-free rate (33.70% vs. 20.22%, p=0.043) and overall <4mm remnant rate (62.79% vs. 48.20%, p=0.044). Clavien-Dindo II+IIIa complications were less in the iVR group (3.48% vs. 12.30%, p=0.03). The results were independent of the surgeon's years of PCNL experience. Pre-operative iVR model visualization benefited surgeons and patients alike. From a surgical standpoint, viewing the iVR model resulted in a safer, more effective percutaneous stone removal procedure.

Evaluation of the Impact of Body Mass Index on the Outcomes of Supine Percutaneous Nephrolithotomy

Objective: This study aimed to evaluate the impact of obesity on the outcomes of supine percutaneous nephrolithotomy (PCNL) in a tertiary care center. Understanding surgical outcomes in obese patients, given their rising prevalence and urolithiasis risk, is crucial for optimizing treatment strategies. Materials and Methods: This retrospective study included data from 256 patients aged 18 and older who underwent PCNL in the Galdakao-Valdivia position between July 2021 and July 2024 at a tertiary care hospital. Patients were categorized into three groups based on their body mass index (BMI): normal weight (BMI: 18-24.9 kg/m²), overweight (BMI: 25-29.9 kg/m²), and obese (BMI: 30-34.9 kg/m²). Demographic data, stone characteristics, operative time, fluoroscopy time, hospital stay, nephrostomy duration, stone-free rates (SFR), and complications were analyzed and compared across the three groups. Results: There was no significant difference between the groups regarding age, sex, stone laterality, location, or size (p&gt;0.05). Median BMI values were significantly different between the groups (p&lt;0.001). The stone-free rates were 79.2%, 77%, and 75% for the normal, overweight, and obese groups, respectively (p&gt;0.05). No significant differences were found in operative time, fluoroscopy time, hospital stay, or nephrostomy time among the groups (p&gt;0.05). Minor and major complication rates were similar across all groups (p&gt;0.05). Conclusion: Obesity does not appear to significantly impact the outcomes of supine PCNL, including operative time, stone-free rates, or complication rates. These findings suggest that with experienced surgeons, supine PCNL is a safe and effective treatment option for obese patients, though further prospective studies are needed to confirm these results.

Factors impacting post-nephrostomy-tube removal urine leak after percutaneous nephrolithotomy: does the calyx of access make a difference?

BackgroundThe aim of this study was to identify the factors that impact the post- percutaneous nephrolithotomy (PCNL) urine leak (UL) following nephrostomy tube removal and to assess if the calyx of entry made any difference.Materials and methodsIn this retrospective study, from April 2016 to May 2019, all the patients undergoing conventional percutaneous nephrolithotomy by a single 24 Fr access with complete stone clearance were evaluated. Patients with urine leak for > 4 h after nephrostomy tube removal were included in the urine leak group (n = 18), while the non-urine leak group (n = 60) comprised patients with urine leak for < 4 h. These groups were compared for demographic, renal, stone-related and peri-operative factors with special stress on calyx of access.ResultsThe urine leak group had significantly older (mean 48 vs. 31 years, p = 0.003) patients with a higher proportion of diabetes mellitus (33% vs. 11%, p = 0.03). They also had a significantly greater (grade ≥ 3) hydronephrosis (55.5% vs. 10%, p < 0.001) and significantly reduced cortical thickness (mean 6.4 vs. 10.3 mm, p = 0.001). They had a nephrostomy tube in situ post-operatively for a longer duration (mean 52.3 vs. 34.5 h, p = 0.002). Interestingly 100% leaks happened from the middle/lower calyx tract and none from the upper calyceal access (p < 0.001). On multivariable regression analysis, grade ≥ 3 hydronephrosis with thin cortex, middle/lower calyceal access and keeping the nephrostomy tube for prolonged duration post-operatively were independent predictors of urine leak. There was no risk of leak from upper calyx access.ConclusionThere is negligible risk of urine leak from upper calyx access so the possibility of hydrothorax after nephrostomy tube removal is minimal.

Barts flank-free modified supine position vs prone position in percutaneous nephrolithotomy: Systematic review and meta analysis

Introduction: Percutaneous Nephrolithotomy (PCNL) has been performed in various positions, including prone position and several modifications of supine position. The Barts flank-free modified supine (FFMS) position is a newly enhanced version of the supine positions. This study aims to compare the outcomes of Barts FFMS and prone position in PCNL. Methods: This study followed PRISMA 2020 guideline and was registered to PROSPERO CRD42024530426. Comprehensive search in PubMed, Sciencedirect, and Scopus was conducted until May 2024. Stone-free rates, complications, surgery duration, fluoroscopy duration, use of nephrostomy, and length of stay were collected. Data were analyzed using RevMan 5.4. Results: A total of 4 studies were included in this review. There was no significant difference in stone-free rates between Barts FFMS and prone positions (OR = 1.12, 95% CI 0.64-1.95, p = 0.70). There were no significant difference in incidence of fever (OR = 0.91, 95% CI 0.38-2.18, p = 0.84), need for blood transfusion (OR = 0.46, 95% CI 0.11-1.88, p = 0.28), and urine leakage (OR = 0.41, 95% CI 0.16-1.05, p = 0.06). The surgery duration was significantly shorter in Barts FFMS position than in prone position (MD = -15.48, 95% CI [(-26.42)-(-4.55)], p = 0.006). There was no significant difference in patients requiring nephrostomy (OR = 0.19, 95% CI 0.01-3.75, p = 0.28). There were no significant difference in fluoroscopy duration (MD = 0.27, 95% CI [(-6.85)-7.40], p = 0.94) and the length of hospital stay (MD = -0.20, 95% CI [(-0.74)-0.33], p = 0.46). Conclusions: The surgery duration was significantly shorter in Barts FFMS position than in prone position. There were no significant differences regarding stone-free rates, complications, fluoroscopy duration, use of nephrostomy, and length of hospital stay. This indicates that neither Barts FFMS nor prone position is superior, and the choice should be based on the surgeon's preference and the patient's clinical status.

Comparative Analysis of Safety and Efficacy Between Anterior and Posterior Calyceal Entry in Supine Percutaneous Nephrolithotomy.

Introduction: One advantage of supine percutaneous nephrolithotomy (sPCNL) is the ability to access anterior as well as posterior calyces, but the safety and efficacy of anterior calyceal entry has never been investigated to our knowledge. We prospectively evaluated patients scheduled for sPCNL comparing anterior and posterior calyceal access. Materials and Methods: After Institutional Review Board approval, we prospectively enrolled 100 consecutive patients undergoing sPCNL from February to September 2023. Primary outcomes included intraoperative complications, blood transfusions, 30-day complication rates, and emergency department (ED) visits or readmissions. Secondary outcomes included stone-free rates (SFR). Results: Seventy-six patients had anterior calyceal entry and 24 had posterior. No significant differences were found in terms of baseline demographics (age, body mass index), stone characteristics (location, density, complexity), or intraoperative features (operative time, location of access). Safety outcomes, including intraoperative complications (1% vs 4%), blood transfusions (3% vs 8%), 30-day complication rates (17% vs 21%), and ED visits (1% vs 0) or readmissions (11% vs 21%) were comparable between groups. Overall SFRs were equivalent (86% vs 90%). Conclusion: We found that anterior and posterior accesses in sPCNL offer similar safety and efficacy, with no significant differences in complications or SFRs. Surgeons can select either approach based on patient anatomy and surgical needs without concern for increased complications. Further research is necessary to confirm these findings and guide best practices for calyx selection in sPCNL.

Supracostal ultrasound guided approach percutaneous nephrolithotomy (SUGA-PNL) versus retrograde intrarenal surgery for large volume isolated upper calyceal stones: a prospective randomized analysis

To assess outcomes of supracostal ultrasound guided approach percutaneous nephrolithotomy (SUGA-PNL) and retrograde intrarenal surgery (RIRS) in isolated large volume upper calyceal stones (UCS). This was a prospective randomized study including patients with isolated UCS > 20mm. The patients were randomized into two groups: group (P) (SUGA-PNL) and group (R) (RIRS). Patients’ demographics, stones characteristics, operative, and postoperative outcomes essentially the stone free rate (SFR) and complications rate were documented. The stone clearance was defined as no fragments or residual fragments less than 2mm in the one month non contrast CT scan follow up. Eighty-nine patients opted to undergo the procedure according to the preoperative randomization. Four patients, 2 patients from each group, lost to follow up and other 2 patients were excluded from group (R) due to a tight ureter. Both groups were comparable as regards the preoperative demographics and stone characteristics. There were statistically significant differences regarding total operative time, the change in hemoglobin level, and postoperative pain score (P: 0.024, 0.010 and 0.032 respectively). The SFR was 88.1% in group (P) compared to 73.2% in group (R) (P: 0.019). Moreover, it did not differ significantly between both groups regarding the intraoperative and postoperative complications. No visceral and thoracic injuries were documented in group (P). On other side, 6 patients (14.6%) from group (R) had different grades of ureteral injury during access sheath placement. SUGA-PNL is a safe and effective treatment modality for UCS > 20mm with a higher SFR than RIRS.

Is it worth using the Comprehensive Complication Index over the Clavien-Dindo classification in elderly patients who underwent percutaneous nephrolithotomy?

To compare the Comprehensive Complication Index (CCI) to the Clavien-Dindo classification (CDC) in an elderly population who underwent percutaneous nephrolithotomy (PCNL) and to identify predictors of postoperative complications in this population. We conducted a retrospective cohort study involving patients 60years and older who underwent PCNL at our Institution between 2009 and 2020. Postoperative complications were considered up to 30days after surgery. Both CDC and CCI were calculated to assess patient outcomes. Length of stay (LOS) and admission to the emergency room (ER) were used as surrogates of postoperative complications. We included 244 patients with a median age of 65 [63-69] years. 15.6% presented postoperative complications, and 2.5% multiple complications. LOS had a correlation coefficient of 0.29 (p < 0.001) and ER admissions had a coefficient of 0.27 (p < 0.001) with both CDC and CCI. Cost of hospitalization based on CDC underestimated CCI-based cost of hospitalization in 0.8% (p = 0.049). Higher American Society of Anesthesiology (ASA) physical status (p = 0.02), Charlson Comorbidity Index (p = 0.008), Guy's classification (p = 0.005), and history of urinary tract infection (UTI, p = 0.047) exhibited significant correlations with postoperative complications. Both CDC and CCI equally correlate with LOS and ER admissions following PCNL in elderly patients. However, CDC underestimates cost of hospitalization in comparison to CCI. We found higher ASA physical status, Charlson Comorbidity Index, Guy's classification, and history of UTI as predictors of postoperative complications after this procedure in this population.

International Alliance of Urolithiasis (IAU) consensus on miniaturized percutaneous nephrolithotomy

Over the past three decades, there has been increasing interest in miniaturized percutaneous nephrolithotomy (mPCNL) techniques featuring smaller tracts as they offer potential solutions to mitigate complications associated with standard PCNL (sPCNL). However, despite this growing acceptance and recognition of its benefits, unresolved controversies and acknowledged limitations continue to impede widespread adoption due to a lack of consensus on optimal perioperative management strategies and procedural tips and tricks. In response to these challenges, an international panel comprising experts from the International Alliance of Urolithiasis (IAU) took on the task of compiling an expert consensus document on mPCNL procedures aimed at providing urologists with a comprehensive clinical framework for practice. This endeavor involved conducting a systematic literature review to identify research gaps (RGs), which formed the foundation for developing a structured questionnaire survey. Subsequently, a two-round modified Delphi survey was implemented, culminating in a group meeting to generate final evidence-based comments. All 64 experts completed the second-round survey, resulting in a response rate of 100.0%. Fifty-eight key questions were raised focusing on mPCNLs within 4 main domains, including general information (13 questions), preoperative work-up (13 questions), procedural tips and tricks (19 questions), and postoperative evaluation and follow-up (13 questions). Additionally, 9 questions evaluated the experts’ experience with PCNLs. Consensus was reached on 30 questions after the second-round survey, while professional statements for the remaining 28 key questions were provided after discussion in an online panel meeting. mPCNL, characterized by a tract smaller than 18 Fr and an innovative lithotripsy technique, has firmly established itself as a viable and effective approach for managing upper urinary tract stones in both adults and pediatrics. It offers several advantages over sPCNL including reduced bleeding, fewer requirements for nephrostomy tubes, decreased pain, and shorter hospital stays. The series of detailed techniques presented here serve as a comprehensive guide for urologists, aiming to improve their procedural understanding and optimize patient outcomes.

Clinical determination of the natural distensibility of the human ureter: initial study.

To define the natural distensibility of the human ureter and evaluate the impact of other possibly favourable factors on ureteric distensibility. A total of 101 patients undergoing ureteroscopic stone removal or percutaneous nephrolithotomy underwent ureteric sizing using sequential passage of 37-cm urethral dilators in 2-F increments while attached to a unique force sensor. Insertion forces were limited to 6 N. After 6 N was attained, an appropriately sized ureteric access sheath was passed. At the conclusion of each procedure, Post-Ureteroscopic Lesion Scale score was determined. Urethral dilators were passed in 61% of patients at ≤14 F; 39% of patients accepted urethral dilators of ≥16 F. The mean dilator size was 14 F. Multivariate logistic regression analysis revealed that preprocedural ureteric stenting and antibiotic use favoured passage of 16-F dilators (odds ratio [OR] 5.16, 95% confidence interval [CI] 1.70-15.62 [P = 0.004] and OR 5.15, 95% CI 1.743-15.243 [P = 0.003], respectively). Neither tamsulosin nor prior urinary tract infection had an impact on ureteric size (OR 0.765, 95% CI 0.281-2.084 [P = 0.601], OR 1.049, 95% CI 0.269-4.089 [P = 0.945], respectively). Using continuous insertion force monitoring and a 6-N threshold, the majority of unstented adult human ureters within our patient population safely accommodated a 14-F dilator. Safe passage of a 16-F dilator at the 6-N threshold was more likely among patients with a preexisting indwelling ureteric stent or patients who were treated with antibiotics within a week of the procedure.

Comparative Study between Outcome of Standard and Tubeless Percutaneous Nephrolithotomy (PCNL) at District Level Tertiary Hospitals in Bangladesh

Renal calculus is one of the commonest problems of the urinary tract. Surgical approach is more effective treatment option to remove it. Among all surgical procedures, Percutaneous Nephrolithotomy (PCNL) has gradually become a preferred option in last two decades for renal calculus that has largely replaced the open approach. Currently, it is the procedure of choice for renal calculus &gt; 2 cm, or those are refractory to ESWL. The crucial step in Standard PCNL is placing a nephrostomy tube. In recent years, it has been reformed as 'Tubeless' PCNL with some modifications in which a Double-J (D-J) stent is placed without any nephrostomy tube for internal drainage. This study was done to compare the outcomes of Standard PCNL and Tubeless PCNL at district level tertiary hospitals in Bangladesh among 46 patients with renal calculus up to 3 cm size. Many authors agree that Tubeless PCNL or its modifications are effective as well as safe. Although, nephrostomy tube is responsible for an increase of post- operative morbidity, in our study, we did not find any statistically significant difference between these two procedures.

Impact of Residual Stone Fragments on Risk of Unplanned Stone Events Following Percutaneous Nephrolithotomy.

Purpose: Residual stone fragments are common after percutaneous nephrolithotomy (PCNL), however, there is an unclear relationship between the presence of these residual stone fragments and the risk of unplanned stone events (USE). We investigated how the size of the largest residual stone fragment (LRSF) impacts the risk of USE post-PCNL. Materials and Methods: We conducted a retrospective cohort study of PCNL between 2018 and 2022. Preoperative computed tomography of the abdomen and pelvis (CTAP) imaging and postoperative CTAP imaging were reviewed. The primary outcome was the incidence of postoperative USE, defined as stone-related emergency department visits or unplanned stone procedures. LRSF were stratified by five thresholds (no postoperative stone fragments vs ≥0 mm, <2 vs ≥2 mm, <3 vs ≥3 mm, <4 vs ≥4 mm, and <5 vs ≥5 mm), and Cox regression was used to compare the impact of these thresholds on the risk of USE. Results: After exclusions, we identified 138 patients who underwent PCNL during the study period; 42 patients had a USE. When applying a 4 mm threshold, 52% of patients with LRSF ≥4 mm experienced USE vs 21% with LRSF <4 mm (log-rank p = 0.0004); similarly, with a 5 mm threshold, 62.5% with LRSF ≥5 mm had such events compared with 21% with LRSF <5 mm (log-rank p < 0.00001). A larger LRSF was associated with a greater risk of having a USE. Conclusion: After PCNL, larger residual stone fragments, particularly those ≥4 mm, are associated with an increased risk of USE. These results demonstrate the value of identifying residual fragments in predicting USE.