Percutaneous nephrolithotomy in the prone and prone-flexed positions: anatomic considerations.

Objectives: Percutaneous nephrolithotomy is commonly performed in the prone position. Knowledge of renal anatomy and the relationship of adjacent organs is essential to minimize patient morbidity and iatrogenic organ injury. We present the anatomical basis for a prone-flexed modification to patient positioning and review the advantages and disadvantages of alternate positions.

Stone attenuation and skin-to-stone distance on computed tomography predicts for stone fragmentation by shock wave lithotripsy.

Objectives: To determine whether stone attenuation and the skin-to-stone distance (SSD) can predict for stone fragmentation by SWL independently. Identifying the factors predictive of shock wave lithotripsy (SWL) outcome would help streamline the care of patients with stones.

Methods: A retrospective review was performed of 111 patients undergoing initial SWL for a solitary, 5-20 mm, renal calculus.