Supine versus prone position in percutaneous nephrolithotomy: a systematic review and meta-analysis

Could pain change position choice? Comparison of pain level, analgesic requirement and hospitalization time in supine and prone percutaneous nephrolithotomy

PURPOSE

Investigation of how position affects postoperative pain levels and hospitalization in patients undergoing percutaneous nephrolithotomy (PNL) surgery.

METHODS

Between August 2019 and December 2022, a total of 156 patients who underwent prone (pPNL) and supine percutaneous nephrolithotomy (sPNL) due to kidney stones were included in the study. Demographic data, preoperative CT scans, laboratory results, transfusion rates, operation durations, complication rates, stone-free rates, analgesic use, nephrostomy removal time, hospitalization duration, fluoroscopy time, hemoglobin decrease and postoperative Visual Analog Scale (VAS) scores were evaluated for all patients. By comparing these data between the sPNL and pPNL groups, the effect of position selection in PNL on pain control, analgesic requirement, and hospitalization duration was examined.

RESULTS

In the comparison of the pPNL and sPNL groups, there was a significant difference between the two groups in body mass index, hounsfield unit, complication rate, analgesic rate, nephrostomy remove time, hospitalization time, operation time, fluoroscopy time and VAS score (p = 0.025, p < 0.001, p = 0.012, p = 0.012, p < 0.001, p < 0.001, p < 0.001, p < 0.001 and p < 0.001, respectively).

CONCLUSION

The shorter operation and hospitalization time in the sPNL group could be attributed to performing surgeries in a physiological position. Additionally, sPNL seems advantageous in terms of patients' pain levels, hospitalization time and VAS scores. One reason for this could be the different areas of access in sPNL and pPNL, which may correspond to different dermatome regions. Considering the low level of pain and reduced analgesic usage, sPNL appears to be advantageous.

Predictive factors for percutaneous nephrolithotomy bleeding risks

Objective

This study aimed to identify predictive factors for percutaneous nephrolithotomy (PCNL) bleeding risks. With better risk stratification, bleeding in high-risk patient can be anticipated and facilitates early identification.

Methods

A prospective observational study of PCNL performed at our institution was done. All adults with radio-opaque renal stones planned for PCNL were included except those with coagulopathy, planned for additional procedures. Factors including gender, co-morbidities, body mass index, stone burden, puncture site, tract dilatation size, operative position, surgeon's seniority, and operative duration were studied using stepwise multivariate regression analysis to identify the predictive factors associated with higher estimated hemoglobin (Hb) deficiency.

Results

Overall, 4.86% patients (n=7) received packed cells transfusion. The mean estimated Hb deficiency was 1.3 (range 0-6.5) g/dL and the median was 1.0 g/dL. Stepwise multivariate regression analysis revealed that absence of hypertension (p=0.024), puncture site (p=0.027), and operative duration (p=0.023) were significantly associated with higher estimated Hb deficiency. However, the effect sizes are rather small with partial eta-squared of 0.037, 0.066, and 0.038, respectively. Observed power obtained was 0.621, 0.722, and 0.625, respectively. Other factors studied did not correlate with Hb difference.

Conclusion

Hypertension, puncture site, and operative duration have significant impact on estimated Hb deficiency during PCNL. However, the effect size is rather small despite adequate study power obtained. Nonetheless, operative position (supine or prone), puncture number, or tract dilatation size did not correlate with Hb difference. The mainstay of reducing bleeding in PCNL is still meticulous operative technique. Our study findings also suggest that PCNL can be safely done by urology trainees under supervision in suitably selected patient, without increasing risk of bleeding.

General versus spinal anesthesia in percutaneous nephrolithotomy: A systematic review and meta-analysis

Background: Percutaneous nephrolithotomy (PCNL) is the preferred treatment for the removal of large kidney stones, sized >20 mm. However, there is still an ongoing debate concerning the best anesthesia for PCNL. This study aimed to compare the efficacy and safety between general and spinal anesthesia for PCNL. Methods: A systematic review and meta-analysis study. A systematic, electronic literature search was performed in several databases, including PubMed, Scopus, and Google Scholar until July 1 st, 2022. The quality of the articles was examined using Crombie's Items (for non-randomized controlled trials (RCTs)) and Jadad Scale (for RCTs). The outcomes assessed were operation time, fluoroscopy time, length of stay, stone-free rate, overall complication rate, specific postoperative complications, cost, pain score, and postoperative analgesic requirement. The article selection was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We assessed four RCTs and eight retrospective studies. Meta-analysis of selected studies was performed using the Review Manager 5.3. Results: General anesthesia resulted in fewer Clavien-Dindo grade II (OR: 0.68; 95% CI: 0.49 - 0.94; p=0.02), major complications (OR: 0.65; 95% CI: 0.45 - 0.94; p=0.02, and lower transfusion rates (OR: 0.70; 95% CI: 0.53 - 0.94; p=0.02). Whereas spinal anesthesia resulted in faster operation time (Mean Difference: -12.98; 95% CI: -20.56 - -5.41; p<0.001, fluoroscopy time (MD: -26.15; 95% CI: -42.79 - -9.50; p=0.002), reduced length of stay (MD: -0.47; 95% CI: -0.75 - 0.20; p<0.001), and lower postoperative analgesic requirement and cost. No significant difference in stone-free rate (OR: 1.08; 95% CI: 0.92 - 1.26; p=0.37). PCNL performed using either general anesthesia or spinal anesthesia is equally safe and effective. Conclusions: Each method of anesthesia has its own advantages and disadvantages. The final choice between general and spinal anesthesia should be based on the patient's condition and surgical team preference.

Which position is more advantageous for percutaneous nephrolithotomy: supine or prone?

Percutaneous nephrolithotomy (PNL) can be performed in a number of different positions. Our aim was to evaluate the convenience and advantages of the supine position following the transition from the prone to the supine position. 94 patients undergoing supine PNL (Group-1) and 93 patients undergoing prone PNL (Group-2) were retrospectively reviewed and included in the study. Patients who underwent mini-PNL (mPNL) were selected from Group-1 and Group-2 and divided into Group-1A supine mPNL patients (77) and Group-2A prone mPNL patients (53). Demographic characteristics, operative data and post-operative parameters were compared between these groups. The operation time was 74.4 ± 21.9 min in Group-1A and 79.2 ± 19.8 min in Group-2A (p = 0.076). The median value of fluoroscopy time was 30 s in Group-1A and 40 s in Group-2A (p = 0.003). In Group-1A, 59 patients had no intraoperative double-J stent (DJS) insertion and 18 patients had DJS insertion, while in Group-2A, 24 patients had no DJS insertion and 29 patients had DJS insertion (p < 0.001). MPNL was performed in 81.9% of patients in the supine position and 57% in the prone position. This difference was statistically significant (p < 0.001). No significant difference was found with regard to the success rate and the complications of mPNL. Fluoroscopy time is shorter in the supine position. Moreover, the insertion rates of DJS are low. With increasing experience, we have found that our standard PNL (sPNL) rate is gradually decreasing and more mPNL is being performed.

Optimal patient position for percutaneous nephrolithotomy in horseshoe kidneys: Traditional prone or supine?

OBJECTIVE

Although it was stated that supine percutaneous nephrolithotomy (PCNL) was associated with relatively shorter surgical times and comparable success and complication rates, there is no consensus in the current literature concerning the safety and efficacy of supine PCNL in patients with horseshoe kidneys. We aimed to compare supine and prone PCNL regarding safety and efficacy in patients with horseshoe kidneys.

METHODS

Data of the patients with horseshoe kidneys who underwent PCNL for renal stones larger than 2 cm between January 2010 and May 2021 were retrospectively reviewed. The study patients were categorized as Group 1 (i.e., supine PCNL-SPCNL) and Group 2 (i.e., prone PCNL-PPCNL). Both groups were compared regarding demographic, clinical, and surgical data.

RESULTS

Sixty-five patients were included. Among these patients, 31 (47.7%) were in Group 1, while 34 (52.3%) were in Group 2. Both groups were statistically similar in terms of demographic data, stone characteristics, perioperative parameters, and complication rates (p > 0.05). There was no statistical difference in terms of additional treatment rates, stone-free rates in the postoperative second-day and third-month evaluations (p > 0.05). Mean surgical time was significantly longer in Group 2 (113 ± 17.1 min) than in Group 1 (90.6 ± 11.3 min) (p = 0.000).

CONCLUSION

Although it is traditionally performed in the prone position, the supine approach is as safe and effective as the prone approach. In addition, the supine approach is associated with significantly shorter surgical times.

Endoscopic Combined Intrarenal Surgery vs Percutaneous Nephrolithotomy for Large and Complex Renal Stone: A Systematic Review and Meta-Analysis

Background: Managing complex and large renal stones with percutaneous nephrolithotomy (PCNL) is difficult because of the likelihood of residual stones and multiple access. Endoscopic combined intrarenal surgery (ECIRS) is introduced as an improvement to the procedure to manage stones in one session. The objective of this systematic review and meta-analysis is to compare the efficacy and safety between ECIRS and PCNL for treating large and complex renal stones. Materials and Methods: We conducted a systematic review in the Embase, Scopus, and MEDLINE databases based on the 2020 Preferred Reporting Items for Systematic Review and Meta-Analyses guideline. Eligible studies comprised both randomized and nonrandomized studies comparing ECIRS and PCNL. Results: A total of five nonrandomized studies and one randomized controlled trial were included. The analysis was divided into two subgroups based on the PCNL type, a conventional PCNL (cPCNL) and a mini-PCNL (mPCNL). The one-step stone-free rate (SFR) of ECIRS were significantly higher compared with both the cPCNL (odds ratio [OR] 5.14, 95% confidence interval [CI] 2.54 to 10.4, p < 0.001) and mPCNL (OR 4.27, 95% CI 2.57-7.1, p < 0.001). There were no significant differences in mean operative time and hemoglobin drop between both groups (p > 0.05). The use of auxiliary procedures was significantly higher in both PCNL groups compared with the ECIRS group (OR 0.19, 95% CI 0.13-0.30, p < 0.001). The overall complication rate of ECIRS was lower compared with PCNL (OR 0.43, 95% CI 0.21-0.85, p = 0.02), especially urosepsis, in which the incidence was lower compared with cPCNL (OR 0.14, 95% CI 0.02-0.78, p = 0.02), but not mPCNL (p > 0.05). Conclusion: ECIRS is an effective and safe treatment particularly for large and complex nephrolithiasis, with significantly higher one-step SFR, a lower necessity for auxiliary procedures, and a lower complication rate compared with PCNL.

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.

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.

X-ray-free ultrasound-guided versus fluoroscopy-guided percutaneous nephrolithotomy: a comparative study with historical control

PURPOSE

To compare the outcomes and complications of supine X-ray-free ultrasound-guided percutaneous nephrolithotomy (XG-PCNL) with fluoroscopy-guided (FG)-PCNL in both prone and supine positions.

METHODS

This was a comparative study that included a prospective cohort and historical control groups. This study analysed 40 consecutive patients who undergone supine XG-PCNL between October 2019 and March 2020. The control groups were composed of historical control formed from the last 40 consecutive patients who underwent FG-PCNL in both supine and prone positions from our PCNL database from January 2018 and September 2019. Patients' demographics, stone characteristics and intraoperative and postoperative outcomes were compared.

RESULTS

A total of 120 patients were classified into the supine XG-PCNL, supine FG-PCNL, and prone FG-PCNL groups (each N = 40). They had similar baseline characteristics and initial stone burden. The supine XG-PCNL group had higher puncture attempts, nephrostomy tube placement, and longer surgery duration than both the supine and prone FG-PCNL groups. However, the stone-free rate was similar in all groups (85%, supine XG-PCNL; 72.5%, supine FG-PCNL; 77.5% prone FG-PCNL; p = 0.39). No significant difference was found in the complication rate and length of stay among the three groups.

CONCLUSION

Supine XG-PCNL is an alternative to both supine and prone FG-PCNL with similar efficacy and complication rates for kidney stone patients. This could be a good alternative to urological centres with no access to fluoroscopy.

X-ray-free Ultrasound-guided Percutaneous Nephrolithotomy in Supine Position Using Alken Metal Telescoping Dilators in a Large Kidney Stone: A Case Report

X-ray-free ultrasound-guided percutaneous nephrolithotomy (PCNL) has been proven to be safe, feasible, and affordable. Kidney dilatation during X-ray-free ultrasound-guided PCNL is mostly using balloon dilators. This report presents our experience of performing X-ray-free ultrasound-guided PCNL in supine position using Alken metal telescopic dilators in a patient with a large kidney stone. A 50-year-old male presented with right complete staghorn stone sized 46×30×24 mm (stone burden: 50,985 mm3 with sphere formula) and grade II hydronephrosis. The computed tomography (CT) scan showed no right ureteric stone, kinking, or stenosis. Ureteral catheter and guidewire were placed retrogradely under ultrasound guidance during cystoscopy. Normal saline was pumped via the ureteral catheter to make artificial hydronephrosis thus assisting the process. Kidney dilatation was performed with Alken metal telescoping dilators. Urine flow from the dilators confirmed that our dilator had reached the collecting system. The stone was identified and fragmented with combination of both pneumatic and shock pulse lithotripter. Double J stent and nephrostomy tubes were inserted at the end of the procedure. All of the steps were performed purely under ultrasound guidance. There was no residual stone after the procedure, confirmed by ultrasound, nephroscope, and postoperative X-ray. There was no significant complication during or after the procedure. The patient was discharged on postoperative day two. X-ray-free ultrasound-guided PCNL in supine position using Alken metal telescoping dilators seems to be a feasible, safe, and cost-effective approach in managing kidney stones, including staghorn and large stones.