Flank versus prone position in percutaneous nephrolithotomy: a meta-analysis of randomized controlled studies

The objective of this study is to assess the safety and efficacy of the flank position in percutaneous nephrolithotomy (PCNL). We searched PubMed, Embase, SCOPUS, the Cochrane database libraries, and the Chinese Biomedical Literature Database, and randomized controlled trials (RCTs) assessing PCNL in flank position are included in this meta-analysis. The related trials met the inclusion criteria were analyzed using RevMan 5.4. Seven randomized controlled trials were included, involving a total of 587 patients. We found that there was a lower decrease in hemoglobin levels in the flank position group compared to prone-position group (mean difference [MD] = - 0.15, 95% confidence interval (CI) - 0.22 to - 0.08, P < 0.00001). Moreover, our meta-analysis demonstrated no significant differences between groups regarding stone-free rate (relative risk [RR] = 1.00, 95% CI 0.93 to 1.06, P = 0.92), operative time(MD = 0.76, 95% CI - 5.31 to 6.83, P < 0.00001), hospital stay (MD = 0.03, 95% CI - 0.32 to 0.32, P < 0.00001), and complications Clavien grade I (RR = 1.01, 95% CI 0.98 to 1.05, P = 0.54), Clavien grade II (RR = 1, 95% CI 0.97 to 1.02, P = 0.78), and Clavien grade III (RR = 1, 95% CI 0.98 to 1.03, P = 0.77). The use of flank position for PCNL is associated with reduced hemoglobin change without an increase in complications. This positioning technique can be considered safe for patients with nephrolithiasis and may be particularly suitable for high-risk individuals such as those who are obese or have decreased cardiopulmonary function. However, further randomized trials are needed to confirm these findings.

Percutaneous nephrolithotomy in horseshoe kidney: comparing ultrasound-guided access in flank position with conventional fluoroscopic-guided in prone position

We conducted this study to compare radiation-free US-guided percutaneous nephrolithotomy (PNL) in the flank position with conventional PNL in the prone position for the treatment of renal stones in patients with horseshoe kidneys. In a retrospective study, 14 HSK patients that were treated with conventional fluoroscopy-guided PNL in the prone position (group A) were compared with twenty-four HSK patients that were treated US-guided PNL in the flank position (group B). Data on baseline characteristics, percentage of successful entries, stone-free rate, duration of admission and complication rate were obtained from data registry. The average duration of the operation was 57.6 min in group B, which was statistically less than group A with 65.9 min (P = 0.001). Access time varied from 10 to 32.4 min (mean = 17.1 min) in group A and 5-29.5 min (mean = 10.9 min) in group B (P < 0.001). Access length had a significant relation to the surgery method so PNL with US-guided had less access length (P = 0.002). There was no significant relationship between the surgery guide and the residual stone rate (P = 0.6). Hemoglobin decrease (P = 0.5), hospitalization duration (P = 0.5) and need for blood transfusion (P value = 0.6) were not statistically different between the two groups. PNL with US guidance in flank position is a safe and effective technique in HSK patients and is associated with fewer complications than the traditional approach as well as reduced operating time, radiation exposure, and its complications.