Analgesic use and complications following upper pole access for percutaneous nephrolithotomy

Upper pole access (UPA) to the kidney optimizes working angles during percutaneous nephrolithotomy (PCNL). However, many surgeons are hesitant to employ UPA due to concerns for increased postoperative pain and complications. In this study, we compare perioperative pain and outcomes for PCNL performed through UPA with middle and lower pole access (LPA).

A retrospective review of PCNLs performed at a single academic institution between 2002 and 2012 was performed. Patient demographics, stone burden, operative characteristics, length of hospital stay, and perioperative complications were recorded. Narcotics administered on postoperative days (POD) 1 and 2 were converted to intravenous morphine equivalents. The Mann-Whitney U, Fisher's exact test, and logistic regression analyses were used for statistical comparison.

Of 350 PCNLs performed on 269 patients, 125 patients underwent primary PCNL through single tract UPA, while primary LPA was utilized in 138 patients. Patients with multiple access tracts (n=6) were excluded. Baseline characteristics between groups were similar except for age; patients with UPA were older (52.6 vs. 46.2 years; p=0.003). Stone burden, operative time, and initial stone-free rate were comparable between groups. Additionally, analgesic requirements were similar on POD 1 (p=0.54) and 2 (p=0.62). There was no difference in the overall complications (p=0.23) or thoracic complications (p=0.43). Although both groups had equivalent stone-free rates after initial PCNL (p=0.78), those with residual stones had a superior stone-free rate after second-look PCNL through UPA (73.3% vs. 44.3%, p=0.035) and a superior overall stone-free rate (94.4% vs. 86.2%, p=0.037).

Patients undergoing PCNL through UPA had a higher ultimate stone-free rate compared with LPA, while postoperative analgesic requirements and overall complication rates were similar between access sites. A trend toward higher thoracic complication rates was observed in the UPA group, although this did not reach statistical significance. Surgeons should not hesitate to utilize UPA when indicated for patients with large or complex stones.