Presentation Authors: Charles Nottingham*, Tim Large, Julia Fiuk, Amy Krambeck, Indianapolis, IN
Introduction: The objective of this study was to compare perioperative outcomes between lower, mid, and upper pole access locations for patients undergoing percutaneous nephrolithotripsy (PNL).
Methods: We have prospectively maintained a high quality database of consecutive patients undergoing PNL at a single institution since April 1999. We queried this database to include patients who had unilateral and single access PNL. We excluded patients who had a contralateral procedure during the same admission. Patients were grouped by the site of PNL access (lower, mid, or upper pole). Among groups, we compared post-operative day one(POD1) stone-free rates as measured by abdominal CT scan or plain-film X-ray and consequent need for a secondary procedures. We further compared postoperative complication rates.
Results: We included 973 patients for analysis (Table 1), with the majority of access locations being in the lower pole (78.6%). Patients across groups had similar age, body mass index (BMI), sex, and stone laterality. Following PNL, patients with lower pole access had the highest rate of residual stone fragments seen on post-operative day 1 imaging compared to patients with mid and upper pole access (43.5% vs 27.8% vs 36.4%, respectively; p=0.028). Additionally, these patients with lower pole access had the highest rate of return to the operating room for a secondary procedure relative to those with mid and upper access (33.7% vs 18.5% vs 29.2%, respectively; p=0.048). Interestingly, mid pole access had the lowest rate of both positive imaging on post-operative day 1 and requirement of a secondary procedure. Patients had low complication rates postoperatively, and no difference in complication rates was observed between groups.
Conclusions: Mid pole single-site renal access during unilateral PNL was associated with the lowest rate of residual stone observed on postoperative imaging and requirement of a secondary procedure, while lower pole access having the highest rates of both residual stone on imaging and requirement of a secondary procedure. The complex calyceal anatomy of the lower pole most likely results in the higher residual stone rates. Fortunately, the complication rate for single-site access is low and does not differ based on access location.