Lateral decubitus position for percutaneous nephrolithotripsy in the morbidly obese or kyphotic patient

Morbidly obese or debilitated patients do not tolerate the prone position used for percutaneous nephrolithotripsy (PCNL) well and may suffer from severe cardiorespiratory compromise in this position. The purpose of this study is to demonstrate a simple way to overcome this difficulty.

Two morbidly obese patients, ages 48 and 32 years, with Body Mass Indices of 47.5 and 43.2 and a 68-year old patient severely debilitated by multiple cerebral infarctions, ischemic heart disease, and kyphosis suffered from relatively high renal stone burdens. For PCNL, the patients were placed in the lateral decubitus position. To obtain an anteroposterior projection in this position, the C-arm fluoroscopy unit was tilted to one side and the operating table to the other. Tract dilation, stone fragmentation, and fragment extraction were performed with the patient in this position.

An attempt to perform PCNL in the prone position in the first patient was aborted because of severe hypoxemia and hypercarbia. In the lateral decubitus position, the procedures were easily performed in all patients without any complications. It was noted that by rotating the C-arm to a perpendicular position, it was possible to perform nephroscopy and use fluoroscopy simultaneously.

We highly recommend using the lateral position for PCNL in morbidly obese patients and in patients suffering from kyphosis. This position is safe and convenient.