Outcomes and complications of percutaneous nephrolithotomy as primary versus secondary procedure for kidney stones: a prospective cohort study.

Introduction: Currently, percutaneous nephrolithotomy (PCNL) is the gold standard of treatment for large renal stones. The high prevalence of urolithiasis is associated with a high recurrence rate increasing the risk of re-intervention. This study aimed to compare the effectiveness and complications of PCNL among patients with previous therapeutic interventions for renal stones. Methods: Between August 2018 and September 2023, 245 patients were prospectively enrolled in this study and who underwent PCNL for renal stones at our institution. We compared patients who had no previous renal surgery (group 1: n=171) with those who had a history of open renal surgery (group 2: n=45) or previous PCNL on the ipsilateral kidney (group 3: n=31). All patients underwent surgery in the Galdakao-modified Valdivia position. Data on stone characteristics and perioperative and postoperative parameters were collected. Technical features, success rates and morbidity were analyzed and compared between the groups. Results: The fluoroscopy time was significantly longer in the group of patients with previous open surgery than in groups 1 and 3 (161.47±52.44, 223.05±33.29, 172.27±30.51 sec, P<0.001). Similarly, the operative time was longer in group 2 (138.20±38.86 min, P<0.001). The immediate stone-free rates in groups 1, 2, and 3 were 74.8%, 72.1%, and 77.4%, respectively (P=0.945). At 1-month, these rates increased to 98.8%, 96.2% and 96.8%, respectively (P=0.857). No difference was detected between the groups in terms of complication rate. The average Hb variation was 1.08±0.82, 1.34±1.01 and 0.94±0.69 g/dl for groups 1, 2 and 3, respectively(P=0.082). Hospital stay was longer in group 2 than in groups 1 and 3 (2.17±1.03, 2.53±1.22, 1.88±1.00 days, P=0.07), respectively. Conclusion: PCNL in patients with a history of renal surgery was associated with longer fluoroscopy and operative time. However, the success and morbidity rates as a secondary procedure were similar to those of PCNL in patients with no previous intervention.

Effect of intrarenal pelvic pressure on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy.

PURPOSE: To investigate the effects of intrarenal pelvic pressure (IPP) on pyelo-tubular backflow and renal cortical blood perfusion during mini-percutaneous nephrolithotomy (MPCNL). METHODS: Dynamic changes in pyelo-tubular backflow and renal cortical blood perfusion were studied in six patients undergoing MPCNL using dynamic contrast-enhanced ultrasonography (CEUS) and IPP monitoring. RESULTS: CEUS of intrarenal pelvic perfusion revealed that renal tubules began to exhibit contrast agent reflux when IPP exceeded 34 mmHg during the MPCNL procedure. There was a positive correlation between renal tubule contrast agent reflux and IPP (P < 0.05). Intravenous CEUS of renal cortical blood flow demonstrated that both intrarenal pelvic perfusion time and IPP during MPCNL significantly affected renal cortical blood perfusion. Intrarenal pelvic perfusion time and pressure were negatively correlated with contrast agent peak intensity (PI) and area under the curve (AUC) (P < 0.05). Longer intrarenal pelvic perfusion times and higher pressures resulted in decreased renal cortical blood perfusion. CONCLUSION: This study directly confirmed through dynamic CEUS and real-time IPP monitoring that an increase in IPP above the threshold of approximately 34 mmHg during MPCNL in patients leads to reflux through the renal tubules and a significant decrease in renal cortical blood perfusion. The safe upper limit for intrarenal pelvic perfusion pressure during MPCNL is approximately 34 mmHg.

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

PURPOSE: 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. METHODS: We conducted a retrospective cohort study involving patients 60 years and older who underwent PCNL at our Institution between 2009 and 2020. Postoperative complications were considered up to 30 days 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. RESULTS: 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. CONCLUSION: 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.

Predictive factors of stone-free rate and complications in patients with proximal impacted ureteral stones undergoing percutaneous nephrolithotomy: based on a new scoring standard.

To evaluate the predictive factors affecting the stone-free rate (SFR) and complications of percutaneous nephrolithotomy (PCN) in the treatment of proximal impacted ureteral stones (PIUS) based on a new scoring standard. The data of 90 patients with PIUS were collected in this retrospective study between January 2015 and June 2023. Univariate and multivariate logistic regression analyses were used to determine factors affecting treatment outcome in terms of SFR and complications. The scoring standard for patients with PIUS was developed based on the univariate logistic regression analyses. In the univariate analysis, stone density (P = 0.015), and stone diameter (P = 0.032) significantly were associated with lower SFR. And degree of hydronephrosis (P = 0.014), Preoperative infection (P = 0.002), and history of lithotripsy (P = 0.045) were associated with occurrence of complications. Multivariate analysis indicated that stone density (P = 0.020), and stone diameter (P < 0.001) were associated with lower SFR; independent risk factors for development of complications were history of lithotripsy (P = 0.024), and preoperative infection (P < 0.001). Additionally, score ≥ 3 was the independent risk factor for both SFR (P < 0.001) and complication rate (P < 0.001). Subgroup analysis shown that there were statistically significant differences between the two groups in terms of stone-free rate (P = 0.032) and complications (P = 0.015). According to the findings of this study, the stone score ≥ 3 was determined as a critical predictive factor of SFR and complications in PIUS patients undergoing PCN based on a new scoring standard. Additionally, PCN has high initial SFR and low complications when dealing with score < 3 PIUS.

Total tubeless percutaneous nephrolithotomy without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis: a randomized controlled trial.

OBJECTIVES: To evaluate the safety and efficacy of total tubeless percutaneous nephrolithotomy (PCNL) without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis. METHODS: This prospective randomized controlled study at a tertiary care medical center was conducted from August 2019 to April 2023. Kidney stone patients diagnosed by computed tomography (CT) without significant hydronephrosis were randomly assigned to two groups: total tubeless PCNL without retrograde insertion of a ureteral catheter (group 1) and traditional PCNL (group 2). The primary endpoint was postoperative complications, while the secondary endpoints included the stone-free rate (SFR), operative time, length of postoperative hospital stay, and medical costs. RESULTS: A total of 99 patients were recruited, including 50 patients in group 1 and 49 patients in group 2. There were no significant differences in postoperative complications and SFR between the two groups (P > 0.05). However, relative to group 2, patients in group 1 had significantly shorter operative time (58.5 ± 25.39 min vs. 82.98 ± 26.02 min, P < 0.001) and length of postoperative hospital stay (1.98 ± 1.72 days vs. 4.39 ± 2.95 days, P < 0.001), as well as significantly lower medical costs (3190.30 ± 590.58 dollars vs. 3552.78 ± 967.79 dollars, P = 0.03). CONCLUSION: Total tubeless PCNL without retrograde insertion of a ureteral catheter for the treatment of kidney stone patients without hydronephrosis is safe and effective for urologists with extensive experience in PCNL. TRIAL REGISTRATION: chictr.org.cn identifier, ChiCTR2000040884, date of registration: 13/12/2020, retrospectively registered.

Is double-J stent mandatory in complete supine percutaneous nephrolithotomy for adult patients with staghorn renal stones?

BACKGROUND: It is controversial whether double-J (DJ) stent insertion is necessary in tubeless percutaneous nephrolithotomy (PCNL) for patients with staghorn stones. We compared the outcomes of using ureteral catheters and double-J stents in tubeless complete supine PCNL (csPCNL) of staghorn stones. METHODS: In this analytical cross-sectional study, from May 2008 to August 2022, 123 patients who underwent tubeless csPCNL were assessed. Patients were divided into two groups by either tubeless csPCNL with DJ stent (Group I; n = 23) or totally tubeless just with perioperative ureteral stent (Group II; n = 100). Demographic characteristics, stone-related factors, perioperative and postoperative parameters were compared in groups. RESULTS: Baseline characteristics were comparable in groups. The operative time in group I was significantly longer than group II (68.26 vs. 55.25 min, P = 0.05). However, the duration of hospitalization in Group I was shorter than the other group (1.81 vs. 2.37 days, P = 0.03). Stone free rate was notably higher in Group I (90.5% vs. 79.8.0%) with no statistically significant difference. No significant differences were found in major complications. Patients in Group II had a significantly shorter time to return to normal life (6.48 vs. 7.91 day; P = 0.043). Multivariable linear regression showed the preoperative creatinine level and stone size can affect the operative time (P = 0.02). In addition, stone number and underlying disease can affect the length of hospital stay (P = 0.007 & 0.030, respectively). CONCLUSION: Although not inserting a double J stent after csPCNL has acceptable results, because of higher residual rate in staghorn stone which cause more incidence of renal colic, longer time of hospital stay and return to normal life, inserting DJ stent is recommended.

Standard v mini percutaneous nephrolithotomy in the supine modified lithotomy position: a randomized pilot study on 10-25 mm stones.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) is the recommended treatment for stones >2 cm in size. The majority of PCNL are still conducted with larger telescopes using tracts up to 30F in size. We have conducted a randomized pilot study comparing mini PCNL with our standard 22F PCNL for renal stones between 10 and 25 mm in diameter. METHODS: Patients were randomized to either PCNL (24F Amplatz sheath/22F nephrosocope) or mini PCNL (18F Amplatz sheath/11F nephroscope). All operations were performed in the modified supine position. Patients were reviewed with imaging to assess stone clearance and complications. RESULTS: Eighteen well matched patients were randomized. All procedures were completed as planned and all were tubeless with no complications. There were no differences in operative time, analgesia requirements or length of stay. Seven of nine (77.75%) standard PCNL were completely stone free at CT review with a 2 mm and a 5 mm fragments in the other patients. Four (44.4%) of the mini PCNL group were stone free, with stone fragments 4-10 mm remaining in the others. 40 patients/arm would be required for an adequately powered study. CONCLUSION: There was no advantage in using mini PCNL compared to our standard 24F PCNL in this pilot study. There may be benefits in using mini PCNL compared to the more widely used 30F PCNL and it may be a more cost-effective alternative to laser pyeloscopic stone procedures.

The association between novel negative pressure ureteroscopic lithotripsy combined with flexible ureteroscopy versus percutaneous nephrolithotomy on stone-free rates: implications for clinical practice and policy.

The correlation between novel negative pressure ureteroscopic lithotripsy (NP-URL) combined with flexible ureteroscopy (FU) and percutaneous nephrolithotomy (PCNL) on stone-free rates (SFR) remains unclear. There is a lack of evidence from Chinese populations regarding the relationship between SFR and NP-URL combined with FU (NP-URL-FU) versus PCNL. We aimed to assess the association between NP-URL-FU and PCNL on SFR. We conducted a cohort study involving 166 participants with 2-4 cm kidney stones. Data on SFR (7 days and 2 months) were collected from all participants. Logistic regression analysis was used to substantiate the research objectives. NP-URL-FU versus PCNL showed an 86% decrease in the 7-day SFR (OR = 0.14, 95% CI 0.07-0.29). The results remained stable even after adjusting for potential confounders. However, no statistically significant association was found between the surgical method and the 2-month SFR. Further exploratory subgroup analyses showed no significant interactions, with all P values > 0.05. Among patients with 2-4 cm kidney stones, NP-URL-FU was associated with a lower risk of incident 7-day SFR than PCNL. However, no statistically significant difference was found in the long-term stone removal rate. Therefore, NP-URL-FU may be a viable alternative surgical option for patients seeking minimally invasive procedures.

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.

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.

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

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Outcomes and Complications of Percutaneous Nephrolithotomy (PCNL): A Single-Center Experience.

BACKGROUND: Urolithiasis is extremely prevalent in Pakistan, with percutaneous nephrolithotomy (PCNL) emerging as the primary treatment modality over traditional open surgery. Despite its effectiveness, PCNL is associated with a risk of complications and residual stones. There is limited data on PCNL outcomes from Southern Punjab, necessitating an evaluation of its efficacy and safety in this region. METHODS: We conducted a retrospective analysis of 399 patients who underwent PCNL at a tertiary care hospital in Muzaffargarh, Pakistan, between October 2016 and September 2022. Detailed preoperative assessments, surgical procedures, and postoperative outcomes were reviewed. Stone clearance and complication rates were assessed, and factors influencing these outcomes were analyzed. RESULTS: The median age of the study population was 39 years, with a male predominance. Stone clearance was achieved in 80.45% (321) of cases, with higher success rates observed in lower pole punctures. Complications occurred in 2% (13) of patients, predominantly hydrothorax following upper pole puncture. Patients with comorbidities had a higher risk of complications (P = 0.097). Residual stones were more common in staghorn stones and larger stone sizes (>3-4 cm). The median operative time was 60 minutes, shorter than reported in the literature, reflecting surgical expertise. CONCLUSION: PCNL is an effective and safe treatment option for urolithiasis in Southern Punjab, Pakistan, with favorable stone clearance rates and low complication rates. Tailoring treatment strategies based on patient characteristics and optimizing surgical techniques are essential for improving outcomes in this population.

Mini-percutaneous nephrolithotomy vs flexible ureteroscopy for 1-2 cm lower pole renal stones: a randomised controlled trial.

OBJECTIVE: To compare the safety and efficacy of flexible ureteroscopy (f-URS) and ambulatory tubeless mini-percutaneous nephrolithotomy (mini-PCNL) in the treatment of 1-2 cm lower calyceal renal stones. PATIENTS AND METHODS: Patients who underwent f-URS and mini-PCNL for the treatment of 1-2 cm lower calyceal renal stones between October 2020 and November 2023 were evaluated in a randomised controlled trial. A total of 72 patients were included in the study. All patients underwent a computed tomography renal colic scan preoperatively, on postoperative Day 1 (POD 1), and at 3 months follow-up. We compared perioperative outcomes, including operative time and hospital stay. Additionally, we evaluated follow-up outcomes, such as the stone-free rate (SFR) and complications. All patients were discharged home on the same operative day. RESULTS: There were no significant differences in preoperative baseline data between the two surgical groups. A significantly longer median operative time was reported in the mini-PCNL group (P = 0.04). The median hospital stay was 5 h and 4 h in the mini-PCNL and f-URS groups, respectively (P = 0.14). On POD 1, the SFR, defined as the absence of residual fragments measuring 0 cm, was 50% for mini-PCNL vs 11.1% for f-URS (P < 0.001). When a total cut-off of <4 cm was utilised, the SFR was 75% in the mini-PCNL group vs 22.2% in the f-URS cohort (P < 0.001). At 3 months follow-up, the SFR remained favourable for mini-PCNL at 72.2% vs 37.1% for f-URS (P = 0.003), with a cut-off of 0 cm, and it increased to 86.1% for mini-PCNL vs 65.7% for f-URS (P = 0.04) when a total cut-off of <4 cm was applied. There was no significant difference in postoperative complications between the two groups. Two patients (5.7%) in the f-URS group required re-treatment. CONCLUSIONS: Ambulatory tubeless mini-PCNL and f-URS are effective treatment options for 1-2 cm lower calyceal renal stones. Both techniques have a comparable hospital stay and complication rates, with a significantly better SFR with mini-PCNL.

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.

Application value of surgical navigation system based on deep learning and mixed reality for guiding puncture in percutaneous nephrolithotomy: a retrospective study.

BACKGROUND: This study was conducted to investigate the clinical value of a navigation system based on deep learning and mixed reality for the treatment of kidney stones with percutaneous nephrolithotomy (PNL), and to improve its theoretical basis for the treatment of kidney stones. METHODS: The data of 136 patients with kidney stones from October 2021 to December 2023 were retrospectively analyzed. All patients underwent PNL, and were categorized into a control group (Group 1) and a surgical navigation group (Group 2) according to puncture positioning method. Preoperative computed tomography (CT) was performed in both groups. In group 1, procedures were performed under standard ultrasound guidance. PNL was performed with navigation system fused with ultrasound to guide percutaneous puncture in group 2. The baseline information and procedural characteristics of both groups were compared. RESULTS: PNL was successfully performed in both groups. No significant difference was found in the baseline date between the two groups. In group 2, real-time ultrasound images could be accurately matched with CT images with the aid of navigation system. The success rate of single puncture, puncture time, and decrease in hemoglobin were significantly improved in group 2 compared to group 1. (p < 0.05). CONCLUSIONS: The application of navigation system based on deep learning and mixed reality in PNL for kidney stones allows for real-time intraoperative navigation, with acceptable accuracy and safety. Most importantly, this technique is easily mastered, particularly by novice surgeons in the field of PNL.

Gall Bladder Perforation During Percutaneous Nephrolithotripsy: Lessons Learned.

Percutaneous nephrolithotripsy (PCNL) is the recommended procedure for patients with large and complex renal calculi. Visceral injuries are rare complications of this procedure. A distended gall bladder (GB) that abuts the right kidney is more prone to needle puncture-related injuries. A GB injury leading to peritonitis portends a poorer prognosis. We report a case of GB perforation that happened after an otherwise uneventful PCNL, which was managed with a prompt intraoperative decision of performing laparoscopic cholecystectomy. The initial puncture yielded a straw-colored, gelatinous aspirate, alerting the treating surgeon. After the completion of the PCNL, a diagnostic laparoscopy was performed. The GB was found to be injured and a bile leak was observed. Elective cholecystectomy was performed. Awareness of this potentially lethal complication and a high index of clinical suspicion is mandatory, as early diagnosis and prompt management can prevent mortality in such patients.

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

OBJECTIVES: To define the natural distensibility of the human ureter and evaluate the impact of other possibly favourable factors on ureteric distensibility. PATIENTS AND METHODS: 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. RESULTS: 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). CONCLUSION: 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.

The effect of erector spinae plane block on postoperative pain and quality of recovery in patients undergoing percutaneous nephrolithotomy.

Percutaneous nephrolithotomy (PNL) is the preferred surgical procedure for treating renal stones larger than 2 cm. Patients may experience significant pain in the postoperative period due to factors such as the catheter entry site and tension in the renal capsule. Erector Spinae Plane (ESP) block provides perioperative muscle relaxation and reduces analgesic use. In this study, we investigated the effect of ESP block on postoperative pain scale and quality of recovery in patients undergoing PNL. The study was conducted with a total of 96 patients, with 45 patients receiving the ESP block and 51 patients not receiving the ESP block. Following the surgery, the visual pain scale (VAS) was completed at 0, 2, 6, 12, and 24 h, and the Quality of Recovery-15 (QoR-15) scale along with the willingness scale were completed at the 24-hour mark. The normal distribution of data was evaluated with the Kolmogorov-Smirnov test, histogram, and skewness-kurtosis coefficients. For comparing paired groups, the Student's T-test was used for normally distributed variables, while the Mann-Whitney U test was used for parameters that did not have a normal distribution. The comparison of postoperative pain, as measured by VAS scores between the groups, revealed statistically significantly lower scores in the ESP block group at 0, 2, 6, 12, and 24 h (p < 0.001, p < 0.001, p < 0.001, p = 0.008, p = 0.010, respectively). Our study results indicated that patients who received the ESP block experienced reduced pain levels and had higher QoR-15 scores compared to those who did not receive the ESP block.

Successful preservation of functional right kidney with giant stones: A rare Chinese case report with literature review.

Renal calculi weighing over 200 g are relative rare in modern urological practice since most stones might cause renal dysfunction before reaching such size. We here reported an extremely rare case of giant stones in single kidney of a 72-year-old Chinese male patient who had 30 years long-term history of lithiasis in the right kidney. These huge kidney stones, total weight 832.6 g were successfully removed with multiple sessions of surgery. Kidney function was relatively stable after long-term medical care in primary care centers. Timely treatment of kidney stones early should arouse more attention worldwide.