Flank free modified supine position: A new modification for supine percutaneous nephrolithotomy

Simplified biplanar (0-90°) versus monoplanar renal puncture technique in flank free modified supine percutaneous nephrolithotomy regarding outcomes and learning curve: Randomized clinical trial

Objective

To evaluate the learning curve and the success rate of the biplanar (0-90°) puncture technique in the flank-free modified supine position in comparison to the monoplanar puncture technique.

Methods

Randomized controlled study included 68 patients more than 18 years with renal stones more than 2 cm from August 2021 to August 2022 were randomly classified by closed envelope method into group A (34 patients) scheduled for monoplanar renal puncture technique in flank-free modified supine PCN. Meanwhile, group B (34 patients) was scheduled for the 0-90° simplified fluoroscopic puncture technique. Morbid obese patients and patients with contraindications for PNL were omitted from the study.

Results

There was no significant difference between both groups regarding stone distribution and patients' demographic data. There was a significant difference between both groups regarding puncture attempts. In 88.2% of patients in group B (Biplanar group), the success of renal puncture occurred from the 1st puncture attempt while in 11.2% of patients in group A (monoplanar group). There was a statistically significant difference between both groups in fluoroscopy time and total operation time (p-value <0.001 & p-value: 0.001), respectively. The stone-free rate was 85.2% vs. 88.2% in both groups, respectively, without significant difference. In this study puncture, attempt trials and puncture time were used as indicators for the easiness and rapid educability of the biplanar (0-90°) fluoroscopic guided renal puncture technique. In the biplanar (0-90°) group after 24 cases, the learning curve had reached the plateau.

Conclusion

Biplanar (0-90°) puncture technique in flank-free modified supine position allows an easy puncture technique with an easy learning curve without affecting the success rate or complication rate.

Oblique supine position versus prone position for percutaneous nephrolithotomy: a systematic review and meta-analysis

Introduction

To compare the efficacy and safety of percutaneous nephrolithotomy (PCNL) in the oblique supine position (OSP) and the prone position (PP).

Aim

To perform a systematic review and meta-analysis to evaluate the efficacy and safety of OSP versus PP for PCNL.

Material and methods

A systematic literature search of PubMed, Ovid, SCOPUS, and citation lists was conducted to identify eligible comparative studies up to November 2022. All studies comparing OSP versus PP for PCNL were included. Statistical analysis was performed with the Collaboration's Review Manager (RevMan) 5.4 software.

Results

Overall, eight studies were included involving 1185 patients (OSP = 634; PP = 551). There were no statistically significant differences between OSP and PP in age (WMD = -0.95 years; 95% CI: -2.12 to 0.21; p = 0.83) or proportion of male patients (OR = 0.02; 95% CI: -0.03 to 0.08; p = 0.43). We found that OSP was performed more frequently for smaller stone size and patients with higher BMI (WMD = -0.1 cm, 95% CI: -0.18 to -0.02; p = 0.01) and patients with higher BMI (WMD = 0.66 kg/m2; 95% CI: 0.29 to 1.03; p = 0.0005). The operation time was shorter in OSP than PP (WMD = -14 min; 95% CI: -27.00 to -1.00; p = 0.03). The reduction of hemoglobin was lower in OSP than PP (WMD = -0.39 g/dl; 95% CI: -0.60 to -0.13; p = 0.03). There was no significant difference in stone-free rate and hospitalization between the two groups (OR = 1.32; 95% CI: 0.98 to 1.78; p = 0.07; WMD = -5.99 h; 95% CI: -17.15 to 5.16; p = 0.29). The overall complications were fewer in OSP than in PP (OR = 0.59; 95% CI: 0.43 to 0.81; p = 0.001), but no difference was observed between the positions with regard to the major complications (Clavien-Dindo score ≥ 3) (OR = 0.76; 95% CI: 0.43 to 1.34; p = 0.35).

Conclusions

OSP showed non-inferior stone-free rate, blood loss, and hospitalization compared with PP. OSP may be superior in terms of operative time and complications than PP.

A new safe and ergonomic manipulation tool for the flank free supine position: 'U-Pad'

INTRODUCTION

One of the most important problems in the supine percutaneous approach to the kidney is the narrow surgical surface area (SSA) in the lumbar region. Herein, the spatial and angular geometric advantages of the U-shaped lumbar pad (U-Pad) used as a new positioning tool for safety and ergonomics in the supine percutaneous approach have been revealed.

MATERIALS AND METHODS

Data of patients who underwent endoscopic combined intrarenal surgery (ECIRS) using the U-Pad for kidney stones between March and September 2021 were prospectively collected. The demographic, preoperative, operative, and postoperative data of patients have been saved. The patients were positioned first with the standard gel pad (Group 1) and then with the U-Pad (Group 2). Both SSA (X and X+Y, cm2) and angular degree (α and β,0) calculations were compared. Fluoroscopy images with the same settings (97 kV/3.00 mA) were visually compared. In geometric data, trapezoidal area formula ((upper base+lower base) X height/2) and goniometer were used to compare with Paired t-test.

RESULTS

Endoscopic combined intrarenal surgery was performed on 17 patients, 13 men and, 4 women, with a median age of 39 (range 32-47). The median body mass index (BMI) was 26.2 (23.5-29.1). Stone localization and features were recorded. The median SSA was calculated as 35.7 cm2 in group 1 and 97.3 cm2 in group 2, and it was calculated that the total SSA increased to 272.5% with a median of 61.6 cm2 extra surgical area. Similarly, the downward manipulation angle was 320 (α0) in group 1, while it was 60.60 (β0) in group 2, and the median extra motion angle was calculated as 28.60 (89.3%).

CONCLUSION

The U-Pad is a safe and rapid tool in the supine percutaneous approach to the kidney, providing at least 2 times the extra SSA and manipulation angle.

Flank free modified supine versus prone ultra mini percutaneous nephrolithotomy in treatment of medium sized renal pelvic stone a randomized clinical trial

INTRODUCTION & OBJECTIVES

percutaneous nephrolithotomy (PNL) is the standard treatment of renal stone more than 2 cm. ultra-mini-percutaneous nephrolithotomy had emerged in the last decade as a new technique in treating renal stones less than 2 cm. in this study we compare between outcomes of (UMP) in modified flank free supine (FFSP), and prone position.

MATERIALS & METHODS

A prospective randomized study was conducted between January 2016 and April 2020, including 122 patients, divided into two matched groups. Group A included 61 patients who underwent UMP in FFSP, and group B included 61 patients who underwent UMP in a prone position. All patients had a single renal pelvic stone 1-2 cm. Patients with a single kidney, renal anomalies, BMI≥40, history of ipsilateral renal surgery, and age less than 18 years were excluded. In both groups, the dilatation was done up to 13 f; a holmium laser was used through a 9f ureteroscope for fragmentation. Nephrostomy tube and ureteric stent were used only when indicated.

RESULTS

122 patients who divided into two groups. The mean age was 40.09±13.63 and 39.67±13.80 years in both groups, respectively. The operative time was 63.64±9.22 and 78.48±9.55 minutes in groups A &B, respectively (P=0.0001). The fluoroscopy time was 3.47±0.56 and 4.45±0.39 minutes in groups A &B, respectively (P=0.0001).no significant difference between both groups regarding operative and post-operative complications. Shift to miniPNL was needed in one patient in group A and four patients in group B due to impaired vision. The hospital stay was 25.36±4.23 and 26.13±4.76 hours in both groups, respectively. The initial stone-free rate was 95.1% and 91.8% in both groups, respectively.

CONCLUSIONS

ultra-mini-percutaneous nephrolithotomy in modified supine position shows comparable results to the prone position regarding stone-free rate, hospital stay, and perioperative complication, with significantly shorter operative and fluoroscopy time.

One-shot dilatation versus metal dilator during percutaneous nephrolithotomy in Flank-free supine position: A Randomized Controlled Study

BACKGROUND

The creation and dilatation of the nephrostomy tract is a fundamental step in PCNL. In one-shot dilatation (OSD), we used a single Amplatz dilator over a central Alken rod. PCNL in the supine position is as effective and safe as in the prone position. The Barts flank-free modified supine position sum several advantages of the different supine positions. We evaluated the efficacy and safety of OSD compared to metal telescopic dilatation (MTD) during PCNL while the patient was in Barts flank-free modified supine position.

MATERIALS AND METHODS

Within 2.5 years, 150 patients with kidney stones candidates for PCNL were randomized into two equal groups according to the dilatation technique. In the OSD group, dilatation was performed using a single Amplatz dilator (30 Fr) and in the MTD group dilatation was performed by sequential MTD (9-30 Fr). All PCNL procedures were done with patients in Barts flank-free modified supine position. Patient characteristics, operative data, and results were collected for statistical analysis.

RESULTS

There are no statistically significant differences between both groups regarding patients' characters. The tracts were successfully dilated in all patients. Statistical analyses show a significant difference (p ˂0.05) between both groups regarding the time of dilatation (sec) (68 ±15 Vs 147 ±18), time of X-ray exposure (sec) (during dilatation; 36 ±10 Vs 61 ±15 and the total; 157 ±16 Vs 181 ±20), hemoglobin loss (mg/dl) (0.7 ±0.2 Vs 1.2 ±0.3) and hospital stay (day) (3 ±0.6 Vs 3.7 ±0.7) with favorable results to OSD. Complication rates were comparable between the two groups.

CONCLUSIONS

One-shot dilatation is efficient as MTD during PCNL while patients in Barts flank-free modified supine position, with less dilatation time, X-ray exposure, blood loss, and hospital stay than MTD.

Outcomes of Flank-Free Modified Supine Percutaneous Nephrolithotomy Based on BMI

OBJECTIVE

To evaluate the impact of body mass index (BMI) on the outcomes of percutaneous nephrolithotomy (PCNL) in the flank-free modified supine position.

PATIENTS AND METHODS

A prospective study was carried out in the urology department during the period from May 2015 to October 2019 on 464 patients admitted for PCNL. The patients were divided into 4 matched groups according to their BMI: group A, normal weight with 18.5 ≤ BMI <25 kg/m2; group B, overweight with 25 ≤ BMI <30 kg/m2; group C, obese with 30 ≤ BMI <40 kg/m2; and group D, morbid obesity with BMI ≥40 kg/m2. All operative data as well as postoperative outcomes are recorded and compared to each other.

RESULTS

The 4 studied groups were matched regarding age. The comorbidities were slightly higher in groups C and D. The operative time and fluoroscopy time were slightly high in obese and morbid obese groups but with no significant difference. The rate of complications either major or minor was comparable in all groups. No significant difference was seen among all groups regarding hemoglobin loss, stone-free rate, hospital stay, and need for auxiliary procedures.

CONCLUSIONS

The outcome of PCNL in flank-free modified supine position is not affected by changes in BMI. The procedure can be performed in obese and morbid obese patients safely with results similar to and comparable to nonobese patients.

Supine Percutaneous Nephrolithotripsy in Double-S Position

Background

At present, the percutaneous nephrolithotripsy (PCNL) is performed both in supine and in prone position. The aim of this paper is to describe an innovative position during PCNL.

Methods

We describe a supine position. The patient's legs are slightly abducted at the hips. The thorax is laterally tilted (inclination 30°–35°) and kept in the right position by one or two gel pads placed between the scapula and the vertebrae. External genitalia can be accessed at any time, so that it is always possible to use flexible instruments in the upper urinary tract. We used this position for a period of 12 months to treat with PCNL 45 patients with renal lithiasis.

Results

All the procedures were successfully completed without complications, using the position we are describing. The following are some of its benefits: an easier positioning of the patient; a better exposure of the flank for an easier access to the posterior renal calyces of the kidney; a lower risk of pressure injuries compared to positions foreseeing the use of knee crutches; the possibility of combined procedures (ECIRS) through the use of flexible instruments; and a good fluoroscopic visualization of the kidney not overlapped by the vertebrae.

Conclusions

This position is effective, safe, easy, and quick to prepare and allows for combined anterograde/retrograde operations.

Minimally invasive percutaneous nephrolithotomy vs standard PCNL for management of renal stones in the flank-free modified supine position: single-center experience

To assess the safety and efficacy of minimally invasive percutaneous nephrolithotomy (mPCNL) as compared to standard PCNL (sPCNL) for management of 2-3-cm renal stones in the flank-free modified supine position. Between September 2010 and December 2013, 150 patients (168 renal units) with 2-3-cm renal stones were prospectively randomized into two treatment groups; Group A (75 patients/87 renal units) treated by mPCNL and Group B (75 patients/81 renal units) treated by sPCNL. In both groups, the patients were placed in the flank-free modified supine position. In mPCNL group, the tract was dilated up to 16.5 F whereas in sPCNL group the tract was dilated up to 30 F. Both groups were compared regarding several perioperative parameters. No significant difference was recorded among both groups regarding fluoroscopy time (4.3 ± 1.3 vs 4.8 ± 2.1 min, p = 0.06), operative time (83.2 ± 17.3 vs 78.6 ± 24.4 min, p = 0.16), hospital stay (4.3 vs 4.5 days, p = 0.76), VAS score (3.2 ± 0.6 vs 3.3 ± 0.8, p = 0.36) and need for analgesia. The mean drop in hemoglobin level and the incidence of bleeding that necessitated blood transfusion were significantly lower in the mPCNL group (0.6 ± 0.1 vs 1.9 ± 1.1 g/dl, p < 0.0001 and 1.2 vs 9.8%, p = 0.03, respectively). Although the stone-free rate was higher in the sPCNL group, but this was statistically insignificant (97.1 vs 95.4%, p = 0.86). Mini-PCNL is effective for managing renal calculi with comparable operative time and stone-free rate to standard PCNL with the merit of higher safety due to lower incidence of bleeding that necessitates blood transfusion.

Immediate versus delayed shockwave lithotripsy for inaccessible stones after uncomplicated percutaneous nephrolithotomy

Objective

To evaluate the efficacy and safety of immediate versus delayed shockwave lithotripsy (SWL) for inaccessible stones after uncomplicated percutaneous nephrolithotomy (PCNL).

Patients and methods

Between December 2011 and June 2014, patients with residual inaccessible stones after uncomplicated PCNL were prospectively randomised into two treatment groups; Group I, immediate SWL and Group II, delayed SWL at 1 week after PCNL. Patients with residual stones of ⩾1.5 cm, a stone density of >1000 Hounsfield units and body mass index of >40 kg/m² were excluded from the study. The following data were reported: patients’ demographics, stone characteristics after PCNL, hospital stay, perioperative complications, stent duration, and stone-free rate (SFR).

Results

In all, 84 patients (51 males and 33 females) with mean (SD) age of 39 (8.5) years were included in the study. Group I included 44 patients, whilst Group II included 40 patients. There was no statistically significant difference amongst the groups for patients’ demographics, stone characteristics, and perioperative complications. The hospital stay was significantly shorter in Group I, at a mean (SD) of 34 (3.7) vs 45 (2.9) h (P < 0.001). The duration of ureteric stenting was significantly lower in Group I as compared to Group II, at a mean (SD) of 12 (4.2) vs 25 (3.5) days (P < 0.001). The SFR was 93.2% and 95% in Groups I and II, respectively (P = 0.9).

Conclusions

Immediate SWL after PCNL is as effective and safe as delayed SWL with a lesser hospital stay and duration of ureteric stenting.

Percutaneous nephrolithotomy in complete supine flank-free position in comparison to prone position: A single-centre experience

OBJECTIVES

To assess the outcomes of performing percutaneous nephrolithotomy (PCNL) in a modified supine position, more feasible for surgeons, anaesthetists, and operating theatre staff, as well as for the patient himself, and evaluating it in comparison to the standard prone position.

PATIENT AND METHODS

A retrospective, case-control study was conducted between January 2011 and December 2015. In all, 197 patient's records were reviewed. The initial 101 patients were operated upon in prone position. From mid-2013, 96 patients were operated upon in a complete supine, flank-free position. The groups were compared in terms of operation time, calculated from positioning the patient after anaesthesia induction, insertion of ureteric catheter, puncture of renal system, until the end of procedure; stone-free rate; hospital stay; and postoperative complications, such as transfusion rate, fever, and urinary leakage.

RESULTS

There were two significant differences between the groups. Firstly, the operation time was a mean (SD) 32.3 (6.6) min shorter for the supine versus the prone position (P < 0.001). Secondly, hospital stay was a mean (SD) 1.2 (0.75) days shorter for the supine vs the prone position (P < 0.001). The complete stone clearance rate (85.4% for supine vs 79.2% for prone; P = 0.2) and postoperative complications (7.3% for supine vs 17.8% for prone; P = 0.02) were comparable in both groups.

CONCLUSION

Supine PCNL is a feasible procedure with similar outcomes in terms of stone-free rate as well as postoperative complications, to the standard prone PCNL. It reduces unnecessary delay that occurs during change of position resulting in significant shortening of the total operation time and surgeons can perform supine PCNL whilst sitting.

Flank-free Modified Supine Percutaneous Nephrolithotomy in Pediatric Age Group

OBJECTIVE

To evaluate the safety and efficacy of pediatric percutaneous nephrolithotomy (PCNL) in the flank-free modified supine position (FFMSP). PCNL in the supine position is increasingly and successfully used in pediatric age group. Different modifications of supine positions have been described; however, the best supine position is not well established and remains a matter of debate.

PATIENTS AND METHODS

This prospective study included 22 children presenting with single renal pelvis stone (2-3 cm) in the period between May 2012 and April 2014. Diagnosis was set by plain x-ray and computed tomography in all patients. PCNL was performed with the patients placed in the FFMSP. The operative time and hospital stay were estimated. The outcome and any perioperative complications or conflicts were recorded.

RESULTS

The study included 22 children (15 boys and 7 girls) with a solitary renal pelvis stone. Mean ± standard deviation age of the patients was 9.5 ± 3.2 years (range, 3-15.5 years). Stone length, operative time, and hospital stay had mean ± standard deviation of 2.4 ± 0.23 cm, 65.1 ± 18.7 minutes, and 4.4 ± 0.9 days. Stone-free rate was 90.9% after 1 session of PCNL. One patient (4.5%) needed a second-look PCNL. Shock wave lithotripsy was performed for another patient. Postoperative fever occurred in 4 patients (18.2%). One patient received postoperative blood transfusion. Postoperative transient urinoma occurred in 2 patients (9.1%).

CONCLUSION

PCNL in pediatric age group via FFMSP was proved to be safe and effective in management of renal pelvis stones of size 2-3 cm. It provides stone clearance rate comparable with that reported of conventional PCNL in the prone position.

Free-flank modified supine vs. prone position in percutaneous nephrolithotomy: A prospective randomised trial

OBJECTIVE

To compare the technical aspects, operative time, safety and effectiveness of percutaneous nephrolithotomy (PCNL) in the free-flank modified supine position (FFMSP) vs. the standard prone position (SPP).

PATIENTS AND METHODS

Seventy-seven patients (47 men and 30 women) with renal stones were enrolled and systematically randomised into two groups, A (39 patients) treated using the FFMSP, and B (38 patients) in the SPP. The outcome was considered as a cure (successful procedure) if the patient became stone-free or had residual fragments of <4 mm in diameter. The operative time (from the induction of anaesthesia to the removal of the endotracheal tube) was measured and any operative complications or conflicts were recorded. The different variables were compared and analysed between the groups.

RESULTS

Patients in both groups had comparable preoperative clinical data and there were no significant differences in the preoperative clinical characteristics. The procedure was successful in 84.6% and 84% of group A and B, respectively. The operative time was significantly longer in group B (SPP) than A (FFMSP). There was no significant difference between the groups in fluoroscopy time and patients' outcome.

CONCLUSIONS

The FFMSP (with a cushion under the ipsilateral shoulder) has similar efficacy and safety as the SPP for PCNL and is associated with a significantly quicker operation.