Purpose We assessed the approachability of the upper calyx through lower calyx access for prone and supine percutaneous nephrolithotomy and used computerized tomography to analyze anatomical factors that may influence it. Materials and Methods A prospective series of 45 patients treated with percutaneous nephrolithotomy were operated on in the prone (20) and supine (25) positions. Computerized tomography simulated access to the lower and upper calyx longitudinal axes were used to measure skin-to-lower calyx distance, thickness of the body wall, muscle and fat, the muscle-to-fat thickness ratio and the angle between the lower calyx tract and the upper calyx axis. Intraoperative approachability to the upper calyx was also evaluated. Results The upper calyx was successfully approached in 20% of prone and 80% of supine percutaneous nephrolithotomies (p E-10). Conclusions Upper calyx endoscopic approachability through the lower calyx is significantly higher in supine than in prone percutaneous nephrolithotomies, possibly due to a thinner body wall, a thinner muscular layer, a lower muscle-to-fat thickness ratio and a wider angle between the lower and upper calyx axes.
- patient positioning
ASJC Scopus subject areas