Standard PCNL Vs Endoscopic Combined Intrarenal Surgery (ECIRS) for Complex Nephrolithiasis in Obese Patients

Primary aim: comparing the efficacy of standard PCNL and endoscopic combined intrarenal surgery (ECIRS) in the Galdakao-modified Supine Valdivia (GMSV) position in a single session for the treatment of complex nephrolithiasis in obese patients. Secondary aim: comparing safety and complications of standard PCNL and ECIRS in the GMSV.

Complex nephrolithiasis including multiple peripheral or branched (partial or complete staghorn calculi) renal stones, is still currently an intractable problem for urologists to achieve stone-free status and minimize complication rates. According to the European Association of Urology Urolithiasis Guidelines, retrograde intrarenal surgery (RIRS) is recommended as first-line treatment for renal stones \< 2 cm, and percutaneous nephrolithotomy (PCNL) is recommended as the gold standard for renal stones ≥ 2 cm in length. Obesity has been identified as an independent risk factor for stone formation in the United States. Obesity (BMI \>35) also places surgical patients at a greater risk of complications, because of the increased incidence in this group of diabetes, hypertension, ischemic heart disease, postoperative deep venous thrombosis, and pulmonary embolism, and because of poor radiographic visualization, obscure anatomic landmarks, more difficult renal access, and inferior stone-free rates. Standard percutaneous nephrolithotomy (PCNL) is the recommended treatment by major guidelines. However, multiple tracts or sessions of PCNL were required to obtain a high stone-free rate (SFR) for complex renal calculi, especially staghorn stones, while procedure-related complications increased concomitantly. To acquire a higher SFR, full access to the entire intrarenal collecting system is the final goal of treatment for these patients suffering from multiple calyceal or peripheral satellite calculi, which is technically challenging by means of RIRS or PCNL monotherapy.