Supine percutaneous nephrolithotomy: Effective approach to high-risk and morbidly obese patients

There are various concerns regarding percutaneous nephrolithotomy (PCNL) in the prone position, especially in the morbidly obese and patients with compromised cardiopulmonary status and stature deformity. We present our experience with supine PCNL with special reference to its technique, indications, advantages, and disadvantages.

A series of 62 patients underwent PCNL in the supine position, 57 under general anesthesia and 5 with epidural anesthesia. Their average age was 48 +/- 14.16 years, and the average bulk of the stone was 316 +/- 275 mm2, with 11% of the patients having staghorn stones and 19 both renal and upperureteral stones. The average body mass index was 24.28 +/- 4.69, and 11% of the patients were morbidly obese. Nearly all patients (93%) had an anesthesia risk of ASA grade 3 or above. Two patients had hip ankylosis. All patients were placed in a modified dorsal lithotomy position with a 45 degrees tilt to the contralateral side. Under ultrasound guidance, the desired calix was punctured in or near the posterior axillary line.

The average hemoglobin drop was 1.62 +/- 1.03 gm/dL, but only 3% of the patients required blood transfusion. None of the patients suffered visceral injury. Nearly all (95%) of the patients were rendered free of stones by the initial PCNL with or without ureteroscopy.

Supine PCNL is an effective and safe procedure in high-risk and obese patients and allows simultaneous management of renal and ureteral stones.