Mini-percutaneous Nephrolithotomy Research Articles

Comparison of safety and efficacy of tubeless vs. conventional mini percutaneous nephrolithotomy in patients with Escherichia coli bacteriuria.

To evaluate the safety and efficacy of tubeless percutaneous nephrolithotomy (PCNL) in patients with Escherichia coli (E. coli) bacteriuria. We conducted a retrospective review of 84 patients with E. coli bacteriuria who underwent PCNL. Patients were divided into two groups according to whether a nephrostomy tube is placed at the end of the procedure. Preoperative clinical data, surgical outcomes, and postoperative complications were compared. Then, regression analysis of factors predicting success rate of PCNL in patients with E. coli bacteriuria was performed. After PCNL, residual fragments ≤ 4mm were considered as success. At baseline, the two groups were similar with regard to age, gender, BMI, underlying disease, hydronephrosis, stone characteristics, and urinalysis. Postoperative fever occurred in 1 patient (3.8%) in the tubeless PCNL group, and in 5 patients (8.6%) in the conventional PCNL group (p > 0.05). There were no significant differences in terms of successful rate, decrease in hemoglobin, pain scores, blood transfusion, and hospitalization expenses. However, the tubeless PCNL group had significantly shorter operative time (60 vs. 70min, p = 0.033), indwelling time of catheter (2 vs. 4 days, p < 0.001), and hospital stays (3 vs. 5 days, p < 0.001) than the conventional PCNL group. In the analysis of factors predicting success, the stone diameter, stone burden, and operative time were associated with success rate of PCNL. It is safe and effective to perform tubeless PCNL in patients with E. coli bacteriuria. Compared to conventional PCNL, tubeless PCNL accelerates patient recovery and shortens hospital stays.

Choosing Retrograde Intrarenal Surgery Versus Mini-Percutaneous Nephrolithotomy in Proximal Ureteric Stones

Background Proximal ureteric stone is one of the common presentations in renal stones disease. Safety, efficacy and stone free rate of retrograde intrarenal surgery and mini percutaneous nephrolithotomy are controversial. Thus, we aim to compare the efficacy, safety and stone free rates of two procedures.MethodsThis was a retrospective observational study including 60 cases divided into group A (Retrograde-intrarenal Surgery) and Group B (Mini-Percutaneous Surgery) between September 2022 to August 2023. Ethical approval was obtained from Institutional review Committee (Reference number: CMC-IRC/079/080-100). Convenience sampling was done.ResultsThe mean age in group A was 43.83 ± 16.92 years and in group B was 46.33 ± 15.78 years with no significant p value (p = 0.112). Post operative haemoglobin changes in group A was 0.266 ± 0.279 gram% and in group B was 1.493 ±0.360 gram% with significant P value of 0.001. Similarly the duration of operation in Group A was 42.43± 13.783 minutes and in group B was 36.30 ± 7.173 minutes with significant P value 0.035. However the stone free rate was higher in group B than Group A without significant P value of 0.064. Both of the groups have minor post operative complication of fever and mild haeamaturia.Conclusions The stones clearance rate of mini percutaneous nephrolithotomy is better than retrograde intrarenal surgery and the safety of retrograde intrarenal surgery is higher than of mini percutaneous surgery.

Vacuum-assisted mini-percutaneous nephrolithotomy is associated with lower rates of infectious complications compared to vacuum-cleaner procedure in patients at high risk for infections: a single-center experience

PurposeTo evaluate the impact of vacuum-assisted mini-percutaneous nephrolithotomy (vamPCNL) vs. vacuum-cleaner mPCNL (vcmPCNL) on the rate of postoperative infectious complications in a cohort of patients with high risk factors for infections.MethodsWe retrospectively analysed data from 145 patients who underwent mPCNL between 01/2016 and 12/2022. Patient’s demographics, stones characteristics and operative data were collected. vamPCNL and vcmPCNL were performed based on the surgeon’s preference. High-risk patients were defied as having ≥ 2 predisposing factors for infections such as a history of previous urinary tract infections, positive urine culture before surgery, stone diameter ≥ 3 cm, diabetes mellitus and hydronephrosis. Complications were graded according to modified Clavien classification. Descriptive statistics and logistic regression models were used to identify factors associated with postoperative infectious complications.ResultsvamPCNL and vcmPCNL were performed in 94 (64.8%) and 51 (35.2%) cases, respectively. After surgery, infectious complications occurred in 43 (29.7%) participants. Patients who developed infectious complications had larger stone volume (p = 0.02) and higher rate of multiple stones (p = 0.01) than those who did not. Infectious complications occurred more frequently after vcmPCNL than vamPCNL (55.9% vs. 44.1%. p = 0.01) in high-risk patients. Longer operative time (p < 0.01) and length of stay (p < 0.01) were observed in cases with infectious complications. At multivariable logistic regression analysis, longer operative time (OR 1.1, p = 0.02) and vcmPCNL (OR 3.1, p = 0.03) procedures were independently associated with the risk of infectious complications post mPCNL, after accounting for stone volume.ConclusionOne out of three high-risk patients showed infectious complications after mPCNL. vamPCL and shorter operative time were independent protective factors for infections after surgery.

Transient ureteral obstruction after mini-percutaneous nephrolithotomy is associated with stone volume and location: results from a single-center, real-life study

PurposeTo evaluate the rate of and predictors of ureteral obstruction after mini-percutaneous nephrolithotomy (mPCNL) for kidney stones.MethodsWe analyzed data from 263 consecutive patients who underwent mPCNL at a single tertiary referral academic between 01/2016 and 11/2022. Patient’s demographics, stone characteristics, and operative data were collected. A nephrostomy tube was placed as the only exit strategy in each procedure. On postoperative day 2, an antegrade pyelography was performed to assess ureteral canalization. The nephrostomy tube was removed if ureteral canalization was successful. Descriptive statistics and logistic regression models were used to identify factors associated with a lack of ureteral canalization.ResultsOverall, median (IQR) age and stone volume were 56 (47–65) years and 1.7 (0.8–4.2) cm3, respectively. Of 263, 55 (20.9%) patients showed ureteral obstruction during pyelography. Patients without ureteral canalization had larger stone volume (p < 0.001), longer operative time (p < 0.01), and higher rate of stones in the renal pelvis (p < 0.01) than those with normal pyelography. Length of stay was longer (p < 0.01), and postoperative complications (p = 0.03) were more frequent in patients without ureteral canalization. Multivariable logistic regression analysis revealed that stone volume (OR 1.1, p = 0.02) and stone located in the renal pelvis (OR 2.2, p = 0.04) were independent predictors of transient ureteral obstruction, after accounting for operative time.ConclusionOne out of five patients showed transient ureteral obstruction after mPCNL. Patients with a higher stone burden and with stones in the renal pelvis are at higher risk of inadequate ureteral canalization. Internal drainage might be considered in these cases to avoid potential complications.

Mini Endoscopic Combined Intra-Renal Surgery (MiniECIRS) with endoview puncture in A 12 month boy. A safe but challenging procedure

Associating minipercutaneous nephrolithotomy and retrograde flexible ureteroscopy (fURS) is called Mini Endoscopic Combined Intra-Renal Surgery (miniECIRS). It's a safe and efficient technique, also in children. The video describes miniECIRS in a 12 month-old boy with an infectious pelvic left stone (16mm) and multiple caliceal stones. The UAS used was a 10FR and the percutaneous access was a 14Fr with Clear-Petra® sheath. The operative time was 180min and blood losses were virtually absent. There were no intra- or post-operative complications and the patient was discharged at the 5th day. After 1 month, double J was removed having a stone free status. MiniECIRS with endoview puncture is a safe and efficient technique when performed by experienced hands. Therefore, it is an alternative to consider for the treatment of complex lithiasis in the pediatric population.

Comparison of STONE Score, Guy's Stone Score, CROES Nomogram, and Seoul National University Renal Stone Complexity Score in Prognosticating Outcomes of Multiple-Tract Mini-Percutaneous Nephrolithotomy: A Retrospective Study.

Objective The objective of this study was to compare the STONE score (Size of the stone, Topography or location, degree of Obstruction of the urinary system, Number of stones, and Evaluation of Hounsfield units), Guy's stone score (GSS), Clinical Research Office of the Endourological Society (CROES) nomogram, and Seoul National University Renal Stone Complexity Score (RSCS) in prognosticating multiple tract mini-percutaneous nephrolithotomy (mPCNL) outcome. Methodology Thisdescriptive retrospective analysis was carried out at the Urology Department, Lady Reading Hospital, Peshawar, Pakistan. Male and female patients in the age range of 18-70 years who underwent multiple tract mPCNL for renal stones from July 1, 2021, to June 30, 2023, were included in the analysis. Results A total of 110 patients were registered. Stone-free status (SFS) was achieved in 78.2% (n=86), and complications were observed in 13.6% (n=15) patients. The odds ratio for STONE score, GSS, CROES scoring system, and RSCS for predicting the SFS was 7.093 (95%CI 2.40-20.89), 9.333 (95%CI 2.92-29.81), 11.70 (95%CI 2.56-53.38) and 3.450 (95%CI 1.25-9.53), respectively. Conclusion Multiple tract mPCNL is a safe and effective technique for the management of renal stones, producing a high stone-free rate. This study demonstrated adequate efficacy and dependability of the four scoring systems in predicting SFS.

Safety and Efficacy of Bilateral Tubeless Supine Mini-Percutaneous Nephrolithotomy for the Management of Bilateral Renal Calculi in Renal Failure Patients

Background: To evaluate the safety, efficacy, feasibility, stone-free rate, and complications of bilateral tubeless supine mini-percutaneous nephrolithotomy (M-PCNL) for bilateral multiple renal calculi with renal failure as a single-stage procedure. Materials and Methods: We conducted aretrospective study from January 2020 to March 2022 in adult patients with bilateral renal or proximal ureteric calculi with renal failure who were subjected to bilateral supine tubeless M-PCNL. Patients on regular hemodialysis before the procedure were excluded. Data regarding the demographic profile, stone characteristics on non-contrast computed tomography (NCCT), duration of surgery, complications, and auxiliary procedures were retrieved from clinical records. Residual stone fragments of≤4mm in NCCT were considered clinically insignificant. The Clinical Research Office of the Endourological Society validation ofClavien score for PCNL complications was used. Results: A total of twenty-seven patients with a mean age of 45.9years were included in this study. The mean size of stone diameter per renal unit was 2.4 ± 0.4 cm. The mean preoperative serum creatinine was 2.8 mg/dL. A total of 62 tracts and 27 sessions were required for complete treatment of all 54 renal units in the 27 successfully treated patients. The average operating time was 75 (52–122) min on both sides. Serum creatinine drop at onemonth postsurgery was statistically significant (p &lt; 0.0001). Mean hospitalization time was 3.6 days [3–6 days]. The primary stone-free rate was 92.5%. Grade I, II, and IVA complications were recorded in three (11.1%), eight (29.6%), and two (7.4%) patients, respectively. Conclusion: Bilateral tubeless supine M-PCNL for bilateral renal calculi in selective patients with renal failure in a single session is a safe, feasible, and effective option which can be carried out without increased morbidity and can be attempted if the first-side M-PCNL has gone smoothly within a reasonable amount of time.

Micro cost-effectiveness analysis of standard vs. mini percutaneous nephrolithotomy

Introduction: Mini-percutaneous nephrolithotomy (mPCNL) has been described as an alternative to standard nephrolithotomy (sPCNL) for select stones. Studies suggest that mPCNL has comparable stone-free rates, with potential for decreased complications and shorter hospital stay. Costs associated with both procedures present a challenge to Canadian institutions due to capital acquisitions of equipment and ongoing disposables. The objective of this study was to compare the cost-effectiveness of both procedures at our institution. Methods: A decision-tree analytic model was developed to compare costs and outcomes of both procedures. Primary outcomes included assessment of total capital, operative, and hospitalization costs. Cost and outcome of peri- and postoperative parameters were obtained using a retrospective analysis of 20 mPCNL and 84 sPCNL procedures on 1–2.5 cm stones between January 2020 and June 2022, and supplemented with internal hospital expenditure records and literature outcome data. Descriptive statistics and regression models were performed. Results: The estimated total cost-per-patient was $7427.05 and $5036.29 for sPCNL and mPCNL, respectively, resulting in cost-savings of $2390.76 in favor of mPCNL with a comparable stone-free rate. The savings were due to lower costs associated with complications and hospital stay. mPCNL had higher capital costs ($95 116.00) compared to sPCNL ($78 517.00), but per-procedure operative costs were lower for mPCNL ($2504.48) compared to sPCNL ($3335.72). Cost-per-case regression of total costs intersected at 5.51 cases when accounting for operative and hospitalization costs, and at 20 cases when only considering operative costs. Conclusions: Despite higher upfront costs, mCPNL may represent a valid, cost-effective alternative to sPCNL for select stones due to clinical and economic benefits in Canadian institutions.

Retrograde Intrarenal Surgery versus Mini-Percutaneous Nephrolithotomy for Lower Calyceal Stones of ≤ 2 cm

Introduction: Renal stones are one of the common urological problems. The optimal management of lower calyceal renal calculi of 1-2 cm is still debatable. The objective of this research is to assess the safety, efficacy, and stone-free rate of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy for the management of lower calyceal stones of 1-2 cm. Methods: A prospective comparative study was conducted among 30 patients which were divided in two group (A and B) prospectively with lower calyceal stones of 1-2 cm. Group A were treated with retrograde intra renal surgery while Group B were treated with mini percutaneous nephrolithotomy. Results: The mean age of patient in Group-A was 44.27±17.10 year and in Group-B was 45.27±16.11 year. The hospital stay in Group-A was 3.47±0.62 and in Group-B was 4.50±0.73 days. The stone size in Group-A was 13.30±2.21 mm and in Group-B was 15.60±2.55 with p-value of 0.381. The duration of operation time in Group-A was79.37±13.96 minutes and in Group-B was 62.53±7.41 minutes with p value of 0.091. Conclusions: Both retrograde intrarenal surgery and mini-percutaneous nephrolithotomy procedure are comparable. Mini percutaneous nephrolithotomy has a better stone free rate and haematuria is more common but retrograde intrarenal surgery has less hospital stay and post operative pyrexia is more common.  

Comparison of stone clearance rate based on upper, middle, or lower calyx puncture in Mini Percutaneous Nephrolithotomy (mPCNL)

Introduction: PCNL is the most common surgical technique used for the management of renal stones, particularly for those with more than 2 cm stones. The aim of this study is to identify which kidney calyx—upper, middle, or lower—when punctured achieves the highest stone clearance rate. Methods: This was a prospective non-randomised study performed in department of urology, KIST medical college from September 1, 2021 to November 16, 2022. Patients who underwent PCNL were evaluated with detailed history, examination, and investigation. All the patients who fulfill the inclusion criteria during study period were included in the study. After preoperative investigation PCNL was done according to standard protocol. Perioperative complication recorded in Performa. Stone-free status was checked after 2 months of surgery with ultrasonography. Results: 100 patients were included in this study among which 59 were male. The mean age of patients was 33.35 years [range 18-65 years]. Upper, middle and lower pole puncture was done in 23%, 33% and 44% patients respectively.  The mean stone burden of the patient was 380.680 mm2. The average time for surgery according to access was 67.34 mins, 63.12mins, and 64.07 mins for the upper calyx, mid-calyx and for the lower calyx respectively. 84.33% of patients had complete stone clearance after 2 months in the USG examination. 91.3% [21] had stone clearance when approached through the upper calyx. It was 87.8%[29] by mid calyx and 75%[33] by lower calyx. Upper calyx puncture had statistical significance in stone clearance rate [P=0.43, P=0.021, P=0.002].  11 had CRIF ≤4mm stone in PCS, and the remaining 6 had residual stone &gt;4mm. In our study, thoracic complications were significantly higher in upper calyx puncture 8[30.4%, 8[24.24% in the middle calyx, and 3[6.8%] in lower calyx [P=0.02, P=0.98, P=0.03] respectively. Conclusion: Upper calyceal puncture can produce the highest stone clearance rate, but it has been associated with significant postoperative morbidity, particularly in the chest. Lower calyx punctures have less intraoperative and postoperative morbidity, but their stone removal rates are lower than those of other procedures. Therefore, the balance between stone clearance rate and morbidity has been achieved using middle calyx puncture.

Comparison of efficacy of intercostal nerve block versus peritract infiltration with 0.25% bupivacaine in percutaneous nephrolithotomy: A prospective randomized clinical trial.

Postoperative pain following percutaneous nephrolithotomy (PCNL) adds to the morbidity of patients requiring additional analgesia. Various modalities of pain control techniques, such as intercostal nerve block (ICNB) and peritract infiltration (PTI), are being studied for better pain management. This study compares the efficacy of ICNB with PTI for postoperative pain management. A double-blinded, prospective, randomized control study was conducted, in which 0.25% bupivacaine, either ICNB or PTI, was given at the puncture site at the end of PCNL. The primary outcome was a comparison of postoperative pain score measured with resting Visual analogue Scale (r-VAS) and dynamic VAS (D-VAS) recorded at 2 h, 4 h, 8 h, 10 h, 12 h, 24 h, and at discharge. Injection ketorolac was given as rescue analgesia. Secondary outcomes include time to first rescue analgesia and total analgesic requirement (TAR). Sixty patients were randomized into two equal groups with 63.3% male and 36.6% female, with a mean age of 37.25 ± 13.09 years. In Group ICNB, 24 (40%) and 6 (10%) patients and in Group PTI, 21 (35%) and 9 (15%) patients underwent standard and mini PCNL, respectively, in each group. All cases were PCNL doen in prone position. The mean R-VAS and D-VAS scores at 2, 4, 8, 12, 24, and 48 h were similar in both groups. The mean TAR was 56.84 ± 0.33.00 mg and 55.54 ± 0.29.64 mg of injection ketorolac in Group ICNB and PTI, respectively (P < 0.894). The time to first rescue analgesic demand were 7.11 ± 4.898 h and 6.25 ± 3.354 h (P < 0.527). Both the groups were comparable in terms of length of hospital stay, stone clearance rate, and complication rate. The ICNB was as efficacious as PTI for postoperative pain control with 0.25% bupivacaine following PCNL.

Safety and Cost-effectiveness of Mini Percutaneous Nephrolithotomy as Day Care Surgery in Paediatric Patients

Background: The increasing prevalence of urolithiasis in paediatric populations necessitates the exploration of efficient and safe treatment modalities. Mini percutaneous nephrolithotomy (PCNL), traditionally an inpatient procedure, has evolved with advancements in surgical techniques and pain management, prompting its consideration as a day care surgery. Objective: This study aims to evaluate the safety, efficacy, and cost-effectiveness of day care mini PCNL in paediatric patients with kidney stones. Methods: This prospective quasi-experimental study was conducted in a pediatric urology department. Patients aged 3 months to 14 years presenting with kidney stones were included. The procedure involved using a 16Fr mini PCNL nephroscope under general anesthesia and fluoroscopic guidance. Stone fragmentation was achieved using a pneumatic lithoclast, and fragmented stones were retrieved with wash and bifrong forceps. Inclusion criteria were stringent, considering factors like stone size, surgery duration, and patient recovery. Postoperative management included early mobilization, oral antibiotics, and analgesics. Follow-up was scheduled at 1 week and 1 month postoperatively. Data analysis employed SPSS version 20, focusing on variables like age, operative time, readmission rates, and cost comparisons. Results: The study involved 92 patients, with a gender distribution of 71.7% male and 28.3% female. The average stone size was 2.2 ± 0.7 cm, and the mean operative time was 74 ± 16 minutes. The mean hospital stay was 11 hours, with readmission rates of 6.7%. The cost savings in day care mini PCNL were significant, with an average reduction of 8000 PKR per procedure compared to inpatient care. The success rate of day care surgery was 93.7%. Conclusion: Day care mini PCNL is a viable, safe, and cost-effective treatment option for pediatric patients with kidney stones. It offers reduced hospital stay, lower costs, and high patient satisfaction without compromising on safety or treatment efficacy.

Mini Percutaneous Nephrolithotomy vs Standard Percutaneous Nephrolithotomy: A Perioperative Decision Support System for Surgical Success Comparison.

This study aimed to rank the features that are important in terms of safety and effectiveness in choosing the surgical method and providing appropriate care to the patient by using the variables examined before and after the surgery to evaluate the success of mini percutaneous nephrolithotomy and standard percutaneous nephrolithotomy surgeries. The features evaluated before and after surgery were ranked according to their importance in the features considered, using Multivariate Adaptive Regression Splines (MARS), LASSO, Ridge, Elastic_net, and Random Forest algorithms as variable selection techniques. There are 278 samples in the relevant data set. Type of surgery (100%), intercostal access (97.75%), kidney opening procedure (94.25%), postoperative creatinine (59.22%), hydronephrosis (52.23%), the number of entries (41.61%), and pre- and post-operative hemoglobin difference (45.13%) were determined as the most critical variables. The MARS algorithm showed the most successful performance, with the lowest mean absolute error (MAE) value of 0.3622, the lowest root mean square error (RMSE) value of 0.3960, and the highest R2 value of 0.3405. Clinical decision support systems can be helpful in eliminating errors and reducing costs. It can also improve the quality of healthcare and aid in the early diagnosis of diseases. Computer-aided decision-making systems can be developed using the results of such products. These systems can provide doctors with better information about their patient's treatment options and improve decision-making. It can contribute to patients being better informed about the surgery results and taking an active role. In conclusion, this study provides essential information that should be included in the surgical decision-making process for patients using medications and with a history of percutaneous nephrolithotomy.

Comment on: "Mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of 10-20-mm kidney stones in patients with ileal conduit: a comparative study".

Comment on: "Mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of 10-20-mm kidney stones in patients with ileal conduit: a comparative study".

Flexible ureteroscopy with novel flexible ureteral access sheath versus mini-percutaneous nephrolithotomy for treatment of 2-3 cm renal stones.

To assess and compare the effectiveness and safety of flexible ureteroscopy (f-URS) with a novel flexible ureteral access sheath (f-UAS) versus mini-percutaneous nephrolithotripsy (mini-PCNL) in treating 2-3 cm renal stones. Retrospectively analyzed consecutive cases that underwent f-URS with f-UAS (12/14 Fr) from January 29, 2022, to November 30, 2022. Consecutive cases that underwent mini-PCNL (18 Fr) from June 5, 2021, to January 26, 2022, were selected as controls. The f-UAS is a novel device with a 10 cm anterior tip that passively bends along with the f-URS to enter the renal calyx. We analyzed demographic characteristics, stone parameters, operative time, stone-free rates (SFR), hospitalization time, and complication. A total of 96 consecutive cases that underwent f-URS with f-UAS and 96 consecutive cases that underwent mini-PCNL were included in the study. There were no significant differences between the two groups in terms of operative time (p = 0.06), stone volume clearance (p = 0.533) and complete SFR (p = 0.266) on the first postoperative day or residual Stone after 1 month (p = 0.407). We observed a significantly shorter postoperative hospital stay (1.4 days vs. 2.1 days; p < 0.001) and a lower decrease in hemoglobin levels (0.39 g/dL vs. 0.68 g/dL; p < 0.001) in the f-UAS group. The mini-PCNL group had a significantly higher overall complication rate (13.5%) compared with the f-UAS group (5.2%; p = 0.048). In the treatment of 2-3 cm renal stones, f-URS with a novel f-UAS may provide a superior alternative to mini-PCNL, potentially challenging its established status.

Comparison of mini-percutaneous nephrolithotomy and retrograde intrarenal surgery for 1-2 cm renal stones: A single-center experience.

Background: The management of renal stones has undergone significant advancements in recent years, with percutaneous nephrolithotomy (PCNL) and Retrograde Intrarenal Surgery (RIRS) emerging as minimally invasive alternatives to traditional Pyelolithotomy. This study aims to assess the effectiveness of Mini-PCNL and RIRS for renal stones measuring 1-2 cm, focusing on operative time, stone clearance, hospital stay, and the need for ancillary procedures. Methodology: This retrospective study collected data from the medical records of patients admitted to The Department of Urology at The Kidney Centre, Karachi, between January 1, 2021, and August 31, 2022. The study included 100 patients who underwent RIRS and 129 patients who underwent Mini-PCNL. Results: It was found that the operative time was statistically similar in both groups. However, the length of hospital stay was significantly higher in the Mini-PCNL group (more than 2 days in 88.4%), whereas in the RIRS group, the majority of patients stayed ≤ 2 days (78%). Overall stone clearance was 82.1%, with a slightly higher clearance rate in patients who underwent Mini-PCNL (85.3%) compared to RIRS (78%), though the p-value was not statistically significant. Conclusion: For renal stones sized 1-2 cm, both RIRS and Mini-PCNL demonstrate efficient treatment options with comparable stone-free rates. RIRS appears more comfortable and less morbid than Mini-PCNL, with a shorter hospital stay. Although Mini-PCNL requires an extended hospital stay to treat 1- to 2-cm renal stones, it is associated with fewer complications and a reduced need for a JJ stent, making it a viable alternative to RIRS in certain cases.

Impact of Renal Access Angle and Speed of Nephroscope Retrieval Movements on the Vortex Effect

To analyze the influence of different renal access angles (AAs) and nephroscope retrieval speeds on the efficacy of the vortex effect (VE) in mini-percutaneous nephrolithotomy (mini-PCNL). This study aimed to understand the poorly understood physical components of the VE. A Pexiglas™ (KUS®) model was built based on the dimensions of a 15/16F mini-PCNL set (Karl Storz). The flow rate was continuous via an automatic pump and calibrated to achieve hydrodynamic equivalence to the real equipment. One experiment consisted of manually retrieving all 30stone phantoms (3mm diameter) utilizing only the VE. Cumulative time to retrieve all stones was measured. An accelerometer recorded instant speeds of the nephroscope every 0.08 seconds (s), and 3 experiments were performed at each angle (0°, 45°, and 90°). A logistic regression model was built utilizing maximum speeds and access angles to predict the effectiveness of the VE. Mean cumulative time for complete stone retrieval was 28.1seconds at 0° vs 116.5seconds at 45° vs 101.4seconds at 90° (P<.01). We noted significantly higher speeds at 0° compared to 45° and 90° (P<.01); however, differences in average and maximum speed between 45° and 90° were not statistically significant (P=.21 and P=.25, respectively). The regression model demonstrated a negative association between increasing maximum speed and VE's effectiveness (OR 0.547, CI 95% 0.350-0.855, P<.01). When controlling for maximum speed, the 0° angle had significantly higher chances of achieving at least a partially effective VE. Increasing the renal access angle or nephroscope extraction speed negatively impacts the effectiveness of the VE. This significantly increased procedure time in the laboratory model, suggesting that the VE is less effective at higher sheath angles.

Comparison of efficacy and safety of flexible ureteroscopy and mini-percutaneous nephrolithotomy for 2-3 cm renal calculi in women: a single-center study.

This study aimed to compare the efficacy and safety of flexible ureteroscopic lithotripsy (FURSL) and mini-percutaneous nephrolithotomy (mPCNL) in the treatment of 2-3 cm renal calculi in women. Clinical data of 186 patients who underwent mPCNL (n=96) and FURSL (n=90) surgery in our hospital from June 2018 to February 2023 were collected. Several parameters were assessed and compared between the two groups, including operation duration, length of hospital stay, cost of hospitalization, pain intensity measured by the visual analogue scale (VAS), patient comfort assessed using the Bruggrmann Comfort Scale (BCS), decrease in hemoglobin levels, changes in blood urea nitrogen (BUN), fluctuations in serum creatinine (Scr), hypersensitive C-reactive protein (hs-CRP) levels, complication rates, immediate post-operative stone-free rate (RSFR), and long-term stone-free rate (LSFR). The comparative analysis of patient age, body mass index (BMI), stone size, computed X-ray tomography (CT) value of stones, number of stones, and comorbidities revealed no statistically significant differences between the mPCNL and FURSL groups (p>0.05). The mPCNL cohort exhibited a markedly lower duration of operation (p<0.001) and BCS score (p<0.001) compared to the FURSL cohort. Nonetheless, the mPCNL cohort demonstrated significantly higher hospitalization expenses (p<0.001), length of hospital stay (p<0.001), VAS score for pain (p<0.001), and level of hemoglobin decrease (p<0.001) in comparison to the FURSL cohort. Moreover, the immediate post-operative stone-free rate (RSFR) was significantly higher in the mPCNL group (p=0.007). The long-term stone-free rate (LSFR), however, showed no significant difference between the two groups (p=0.160). Furthermore, the FURSL group exhibited significantly fewer overall complications in contrast to the mPCNL group (p=0.006). mPCNL and FURSL are both safe and effective surgical methods for treating 2-3 cm renal calculi in women. However, FURSL holds distinct advantages, including minimally invasive procedure, accelerated recovery, reduced cost, and lower incidence of complications.

A comparative analysis of the efficacy and safety of mini-percutaneous nephrolithotomy performed in the supine and prone positions for the treatment of pediatric kidney stones: a single-center experience.

Mini-percutaneous nephrolithotomy (MPCNL), which has a smaller tract size (14-20 Fr) than conventional percutaneous nephrolithotomy, has been shown to be safe and effective in pediatric patients with large and complex upper urinary tract stones. This study aimed to compare the efficacy and safety of MPCNL between the supine and prone positions in a pediatric population. The data of pediatric patients who underwent MPCNL at our center between January 2010 and March 2023 were retrospectively analyzed. According to the surgical position, the patients were divided into the prone (Group P) and supine (Group S) groups. In both groups, dilatation was performed using 14-18 Fr metallic dilators. The two groups were compared in terms of perioperative data, postoperative stone-free rates (SFRs), and complications. There were 36 (59%) patients in Group P and 25 (41%) patients in Group S. Stones were mostly located in the pelvis (49.2%) and second most frequently in the lower pole (27.9%). Fluoroscopy time was shorter in Group S but did not statistically significantly differ compared to Group P (p = 0.181). However, operation time was statistically significantly shorter in Group S (73.8 ± 35 vs. 99.8 ± 37.4min, p = 0.008). Although there was no significant difference, relatively higher SFR were detected in Group S (88% vs. 83%, p = 0.725). Endoscopic combined intrarenal surgery (ECIRS) was performed on six (24%) patients in Group S, and the SFR was 100% among these patients. There was no significant difference between the two groups in terms of the presence of complications (16.7% vs. 16%, p = 0.945). Both supine and prone MPCNL appear to be safe and effective in the pediatric age group, with similar stone-free and complication rates. In the supine procedure, the operation time is shortened compared to the prone. In addition, simultaneous retrograde access has the potential to increase the overall success rate of surgery.

Mini Percutaneous Nephrolithotomy in Ectopic Lumber Kidney: A Case Report

The chance of the development of hydronephrosis and the formation of stones is more in the ectopic kidney. Treatment of stones in ectopic kidneys is challenging for urologists due to abnormal location and rotation of the kidney and unfavourable local anatomy. We herein report a case of stone in a lumber kidney successfully managed by mini percutaneous nephrolithotomy (PCNL) in a prone position. A 55-year-old male presented with right lower abdominal pain. His CT scan of the KUB reveals the right kidney is in an ectopic location and has a hyperdense structure measuring about 15 mm in length, seen in the right renal pelvis with mild dilatation of the pelvicalyceal system. The patient underwent right-sided prone mini PCNL under the subarachnoid block (SAB), and complete stone clearance was achieved. There was no adverse event during or after surgery or post-operative blood transfusion. Bangladesh J. Urol. 2022; 25(2): 122-125