MP27-03 ANALGESIC USE, COMPLICATIONS, AND STONE-FREE RATE FOLLOWING UPPER POLE ACCESS FOR PERCUTANEOUS NEPHROLITHOTOMY

Abstract

INTRODUCTION AND OBJECTIVES: Upper pole access to the kidney optimizes working angles during percutaneous nephrolithotomy (PCNL). However, many surgeons are hesitant to employ upper pole access (UPA) due to higher reported complication rates and concerns for increased postoperative pain. The purpose of this study is to compare outcomes for PCNL performed via UPA versus middle and lower pole access (LPA). METHODS: A retrospective review of PCNLs performed at a single academic institution between 2002 and 2012 was performed. Patient demographics, stone burden, operative time, length of hospital stay, estimated blood loss, and perioperative Clavien-Dindo complication score were recorded. Stone-free status was defined as no remaining fragment 4mm or greater. Narcotics administered on postoperative days 1 and 2 were converted to intravenous morphine equivalents and recorded. UPA and LPA groups were compared using Mann-Whitney U, Fisher's exact test, and logistic regression analyses, with significance set at p<0.05. RESULTS: A total of 125 patients underwent primary PCNL via single tract UPA, while single tract LPA was utilized in 138 patients. Baseline characteristics were similar except for age; patients with UPA were older (52.6 vs. 46.2 years; p=0.003). Stone burden, operative time, and estimated blood loss were comparable between groups. Additionally, morphine-equivalent analgesic requirements were similar on post-operative day 1 (UPA 18.2 mg, LPA 18.7 mg, p=0.50) and 2 (UPA 16.4 mg, LPA 16.7 mg, p=0.63). There was no significant difference in overall complications (UPA 26.4%, LPA 18.8%, p=0.18) or thoracic complications (UPA 5.6%, LPA 1.4%, p=0.09). Although both groups had equivalent stone-free rates after initial PCNL (UPA 73.6%, LPA 72.5%, p=0.89), those with residual stones had a superior stonefree rate after second-look PCNL via UPA (71% versus 36%, p=0.007). Patients with UPA had a superior overall stone-free rate (94.4% versus 85.5%, p=0.024), which remained significant on logistic regression analysis after adjustment for age, gender, fluoroscopy time, and overall stone burden (p=0.046). CONCLUSIONS: Patients undergoing PCNL via UPA had a superior overall stone-free rate compared to LPA. Postoperative analgesic requirements and complications rates were similar between access sites. Surgeons should not hesitate to utilize UPA when indicated for patients with large or anatomically complex stones.