Supine percutaneous nephrolithotomy (PCNL) in renal stone patients

Percutaneous nephrolithotomy (PCNL) is considered the best treatment option for large and complex renal stones, which are difficult to manage by using other treatment modalities like ureteroscopy and shock wave lithotripsy (SWL) and retrograde intra renal surgery (RIRS). This minimally invasive surgical intervention has a high stone clearance rate with low morbidity. Traditionally PCNL is being done in prone position but it has evolved many a fold and was originally described in supine position by Valdivia et al. In this position the direction of the tract is posterior and thus preserves a low pressure in the renal pelvis, and thereby reduces the risk of fluid absorption and allows spontaneous clearance of fragments by gravity directed flow of fluid. Later on some new positions were described after doing some modification in the original Valdivia. Currently, PCNL is the treatment of choice for large renal stones, staghorn calculi, or in stones occurring in kidneys with abnormal anatomy. The morbidity of the PCNL in prone position been well documented. However, the supine approach’s safety and efficacy and potential advantages likely explain the increasing use of the supine position for stone management over the last ten years .  Nevertheless, despite previously reported advantages, it has been pointed out that the supine position has its flaws, such as prolonged operative time in the case of larger stones. At present, current guidelines do not support one approach over the other. Therefore, controversy still exists regarding which position is safer and more effective for PCNL.  In this study we aim to investigate the feasibility and outcome of the supine PCNL position by analyzing preoperative, intraoperative and post operative data and conclude outcomes of this position.