Kidney displacement in complete supine PCNL is lower than prone PCNL

Comparison of safety and efficacy of different positions in percutaneous nephrolithotomy: a network meta-analysis

OBJECTIVES

Various new positions for percutaneous nephrolithotomy (PCNL) were proposed to reduce the limitations of the traditional position. This study was aimed to evaluate the efficacy and safety of the different PCNL positions.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for relevant randomized controlled trials (RCTs) up to 18 April 2023. The authors collected five common surgical positions used for PCNL: oblique supine position (OSP), supine position (SP), flank position (FP), split-leg oblique supine/flank position (SLP), and prone position (PP). Paired and network meta-analysis were conducted to compare relevant outcomes, including complications, operative time, stone-free rates, hospital stay, and hemoglobin loss among these different positions.

RESULTS

The study included 17 RCTs with a total of 1841 patients. The result demonstrated that SLP significantly outperformed in terms of decreasing operation time (FP vs SLP MD- MD-41.65; OSP vs SLP MD 28.97; PP vs SLP MD 34.94), hospital stay, and hemoglobin loss. Ranking probabilities showed SLP had highest stone-free rate. Prone position was more likely to occur complications than others. Based on SMAA model, the benefit-risk analysis suggested the SLP was the optimal position in PCNL.

CONCLUSIONS

For PCNL, the split-leg, flank, supine, and OSPs are as secure as the prone position. Further RCTs are necessary to confirm the outstanding safety and efficacy of split-leg position. Besides, the position should be selected regard for the patient's demands, the surgeon's preference and learning curve.

Prone versus supine percutaneous nephrolithotomy: a systematic review and meta-analysis of current literature

INTRODUCTION

Percutaneous nephrolithotomy (PNL) can be performed either in prone or supine position. This study aimed at gathering together randomized controlled trials (RCTs) comparing efficacy and safety between prone and supine PNL.

EVIDENCE ACQUISITION

Systematic review of literature was conducted using the Scopus, Medline and Web of Science databases. Study selection, data extraction and quality assessment were independently assessed by two authors. Meta-analysis was performed with Review Manager 5.3. Sensitivity analyses were performed to exclude studies with high risk of bias.

EVIDENCE SYNTHESIS

Pooled data from 12 studies including 1290 patients were available for analysis. Only one study was found to have overall low risk of bias. Significantly shorter operative time was found in favor of supine PNL (mean difference 13 minutes, 95% confidence interval [CI]: 3.4-22.7; P<0.01). Stone-free rate (SFR)≥14 days after surgery was significantly higher in prone PNL (odds ratio [OR]=2.15, 95% CI: 1.07-4.34; P=0.03). Significantly higher fever rate was found in prone PNL (OR=1.60, 95% CI: 1.03-2.47; P=0.04). Overall SFR, hospital stay length, complications rate, transfusions rate and blood loss, as well as non-lower calyx puncture rate, puncture attempts and tubeless intervention rate did not differ between prone and supine PNL (P>0.05).

CONCLUSIONS

Efficacy of PNL seems balanced between prone and supine position, with comparable overall SFR and shorter operative time in favor of supine PNL. Safety of PNL appears in favor of supine PNL, with lower fever rate. Because of study heterogeneity and possible risks of outcome bias, results from this study should be interpreted with caution. Altogether, both prone and supine PNL account for appropriate therapy options.

Supine versus prone position for percutaneous nephrolithotripsy: A meta-analysis of randomized controlled trials

OBJECTIVE

To compare the safety and efficacy of percutaneous nephrolithotripsy (PCNL) in supine versus prone position for patients with renal or upper ureteral calculi.

METHODS

A systematic search of Pubmed, Embase and Cochrane Central Register of Controlled Trials was performed to identify all eligible studies. All included randomized controlled trials (RCTs) were evaluated based on the inclusion and exclusion criteria. After quality assessment and date extraction, a meta-analysis was performed using RevMan 5.3 software.

RESULTS

A total of 15 RCTs with 1474 patients were included in our meta-analysis. Pooled data showed that PCNL in supine position could significantly reduce the operative time [weighted mean difference (WMD) -12.02, 95% confidence interval (CI) -20.49 to -3.54, p = 0.005] and rate of fever [risk ratio (RR) 0.67, 95% CI 0.46 to 0.97, p = 0.03] compared to prone position. In addition, no significant differences could be found between groups in stone-free rate (p = 0.31), hospital stay (p = 0.59) and rate of overall complications (p = 0.11), mainly including urinary leakage (p = 0.83), pleural effusion (p = 0.74) and blood transfusion (p = 0.58).

CONCLUSIONS

The current study found comparable stone-free rate and significant lower rate of postoperative fever in supine PCNL compared with prone PCNL. PCNL in supine position could be a safe and efficient choice for patients with renal or upper ureteral calculi.

Prospective evaluation of kidney displacement during supine mini-percutaneous nephrolithotomy: Incidence, significance, and analysis of predictive factors

INTRODUCTION

Kidney displacement may alter the quality of renal puncture during percutaneous nephrolithotomy (PCNL). The aim of this study was to identify the rate of kidney displacement and parameters associated with kidney displacement in patients who underwent supine mini-PCNL.

METHODS

Data of 98 consecutive patients who underwent mini-PCNL was collected prospectively. The patients were grouped as displacement-positive vs. -negative. The parameters collected were age, gender, body mass index, side of the kidney, punctured calyx, fluoroscopy time to successful puncture and tract dilation, stone-free and complication rates, stone diameter, length of the renal artery, and quantity of peri-renal and abdominal fat. Groups were compared for the above listed parameters and logistic regression analysis was performed to identify factors associated with kidney displacement.

RESULTS

There were 34 and 64 patients in the displacement-positive and -negative groups, respectively. Groups were similar for stone-free and complication rates. Fluoroscopy time to puncture and tract dilation were longer in the displacement-positive group. Groups were different for renal artery length and peri-renal fat measurements. In multivariate analysis, lower pole puncture, renal artery length, and peri-renal fat measurement were found to be independent predictors of kidney displacement.

CONCLUSIONS

Kidney displacement does not alter the success and complication rates, but is associated with longer fluoroscopy times during supine PCNL. In the current study, parameters in preoperative non-contrast computerized tomography (NCCT) associated with kidney displacement were identified. We recommend surgeons evaluate and take into account these parameters during preoperative planning to establish better outcomes and diminish fluoroscopy times.

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-suspended versus prone percutaneous nephrolithotomy: changes of haemodynamics, arterial blood gases and subjective feelings

BACKGROUND

The flank-suspended position was adopted in percutaneous nephrolithotomy (PCNL), and haemodynamics, blood gas variables and subjective feelings were examined with an attempt to explore the effect of the operative position in PCNL on the body's inner environment and patient comfort.

OBJECTIVE

The influence of the flank-suspended and prone position on haemodynamics, arterial blood gases and subjective feelings in patients receiving PCNL was examined.

DESIGN, SETTING AND PARTICIPANTS

A total of 100 patients with kidney stones who underwent PCNL during January 2010 to January 2011 were divided into flank-suspended groups (n = 50) and prone groups (n = 50) at random in terms of the operative position. The blood pressure, heart rate, respiratory frequency and oxyhaemoglobin saturation and blood gas variables were determined at different time points (before the operation, after position change, 30 min after the start the operation and immediately after the operation). Visual analogue scale (VAS) scoring system was employed to define the posture comfort, dyspnoea and puncture-site pain 24 h postoperation in the patients. All the measures were compared between patients in different positions at different time points.

STATISTICAL ANALYSIS

Paired t-test was employed in the comparison of measures detected at different time points in the same group. Two-group comparison was subjected to t-test. A p value less than 0.05 was considered statistically significant.

RESULTS AND LIMITATIONS

The blood pressure was decreased within and after the operation in both groups, substantially in the prone group, significantly lower than that before the operation (p&lt;0.05). No significant differences in the heart rate, respiratory frequency and oxyhaemoglobin saturation were noted among the different time points in the same group. Blood gas analysis showed that pH value and base excess were profoundly reduced within and after the operation in the two groups, significantly lower than those before the operation, and the decrease was most manifest in the prone group. There was no difference in the blood sodium and potassium among the different time points in each group. The flank-suspended group was superior to the prone group with regard to posture comfort and dyspnoea degree but not puncture-site pain 24 h postoperation.

CONCLUSIONS

Flank-suspended and prone PCNL affects the haemodynamics, blood gas variables and subjective feelings of patients to a varying degree. The flank-suspended PCNL possesses advantages over prone PCNL such as little influence on haemodynamics and blood gas variables, satisfactory posture comfort, less dyspnoea and easy access to vital sign observation.

How well tolerated is supine percutaneous nephrolithotomy?

PURPOSE OF REVIEW

Supine percutaneous nephrolithotomy (PCNL) has been described in 1988 and several modifications followed since. Despite claimed benefits, supine PCNL is still neglected by the majority of urologists. Lack of experience and the fear of complications are possible explanations for the resistance to supine positioning. This review evaluates recent literature on the use of supine PCNL, focussing on benefits and safety.

RECENT FINDING

The Clinical Research Office of the Endourological Society Global Study and several (retrospective) reports comment on efficacy and safety of PCNL, differences in techniques, or identify conditions and patient factors for best practice. Anesthesiologic benefits (especially in the high risk, cardiopulmonary compromised, patient) and anatomical advantages are described in supine position theoretically favoring safety of supine PCNL. However, there are no prospective randomized studies conducted to support this assumption. Overall, benefits in efficacy or safety, of one position over the other, are not yet proven.

SUMMARY

Supine PCNL has advantages in selected patients. Ultimately, the decision on position should be made on patient's characteristics and surgeon's preference and experience.