[Valdivia supine position as the best option for percutaneous surgery of renal calculi in morbidly obese patients].

INTRODUCTION: Treatment of the morbidly obese patient with symptomatic renal calculi is an interesting urological challenge. Extracorporeal shock wave lithotripsy is frequently not possible for several reasons, and many urological centers match these patients as one of the residual indications for open surgery of kidney lithiasis. MATERIAL AND
METHOD: Two patients with body mass index more than 50 k/m2 and symptomatic kidney stones were treated with percutaneous nephrolithotomy in the supine position described by Valdivia (slightly lateralized supine decubitus). Standard instrumentation for percutaneous surgery and the semi-rigid ureteroscopy were used, through an Amplatz sheath proximally transfixed with a polypropylene stitch, so to avoid its lost under the fatty skin. Both patients were rendered stone-free without significant morbidity. DISCUSSION: The advantages of Valdivia position in those patients are clear, both for the commodity of the surgical team, -because time may be spared and help needed to mobilized the patient is less-, as well as for what concerns to the anesthesia, because cardio-respiratory restrictions created by a general anesthesia in prone are greater and more severe in the obese patient. This position seems to be more suitable than other ones recommended for percutaneous nephrolithotomy in the obese patients, such as prone decubitus on a surgical saddle, or lateral decubitus position, that may compromise the radiological control of the operation.