The following is the summary of “Retrorenal colon in pediatric patients with urolithiasis: Is the supine position for PCNL advantageous?” published in the December 2022 issue of Pediatric urology by Emiliani, et al.

When other methods have failed, percutaneous nephrolithotomy (PCNL) is a viable option for the removal of large, complex stones from children’s kidneys. Conventional PCNL treatment positions place the patient either prone or supine, with the former being the norm. The goal of this study was to use radiological images to assess the prevalence of retrorenal colon (RRC) in both the supine and prone positions in pediatric patients, as RRC is one of the most dreaded consequences of this surgical method. All abdomen CT scans performed at one institution on individuals younger than 18 from 2017 to 2019 were retrospectively reviewed. A uro-radiologist was consulted to determine the safest and most effective route for percutaneous puncture into the upper, middle, and lower calyces of both kidneys while the patient was lying prone and supine. 

We used the chi-square and student’s t tests to analyze the data. 44 children had CT scans, totaling 50 scans. The average age of patients was 12.6 years, and 71.4% were male. 50 scans were taken when the patient was lying on their supine side, and the same number were taken while they were lying on their prone side. The right kidney (RK) only showed RRC in the prone position, while the left kidney’s (LK) lower calyx had a substantially higher incidence of RRC in the prone position than in the supine position, 28% vs 4% (P=0.049). When comparing the RK and LK, the spleen was more common (61.9% vs 97.7%), although the difference was not statistically significant.

With a frequency of less than one percent in adults, colon damage is a major cause for concern prior to PCNL surgery. A total of 3 patients (12%) were found to have RRC when lying supine, while 7 patients (28%) were found to have RRC when lying prone (P=0.15). These numbers are greater than those seen in the research for adults (supine: 1.7%-10%; prone: 6.8%-20%), however there are no reports on this subject in the literature to make a fair comparison. This is the first investigation into the occurrence of RRC in kids by body part. In the lower calyx of the left kidney, the incidence of RRC for an ideal puncture was substantially higher in the prone position than in the supine position, while in the right kidney, the RRC only occurred in the prone position.

Source: sciencedirect.com/science/article/abs/pii/S1477513122003369