Upper Pole Access for Prone Percutaneous Nephrolithotomy: Advantage or Risk?

Objective: To analyze the outcomes of upper pole access during percutaneous nephrolithotomy (PCNL), an option pole often avoided due to the concern for pleural injury. Methods: We retrospectively collected data on patients undergoing PCNL at our institution. Patients were divided into 3 groups according to access: supracostal upper calyx (group 1), subcostal upper calyx (group 2), and nonupper calyx (group 3). Preoperative imaging was reviewed to assess stone burden, Hounsfield units (HU), location, and Guy's Stone Score. Patients were considered stone-free if residual fragments were 3 mm or smaller on CT scan. Results: We analyzed 329 PCNLs (left: 174; right: 155). Stones had a median size of 32 mm, 800 HU, and Guy's Stone Score of 2. Groups 1, 2, and 3 had 119, 108, and 102 patients, respectively. The 90-day complication rate was 20.4% (7.9% Clavien 3-4). Group 1 patients, with higher BMI and larger stones, had higher SFR than group 3 (89.9% vs 79.4%, P = .038), but with a significantly higher risk of complications (P = .001). Within group 1, left PCNL (7.0% vs 24.2%, P = .016) and BMI ≥30 (6.9% vs 25.0%, P = .013) carried a lower risk of chest tube insertion. There was no difference in complications between groups 2 and 3 (1.9% vs 2.9%). Conclusion: Upper pole access is safe and effective, particularly if done below the ribs. Supracostal access is an effective option to achieve higher stone-free rates in complex stones, while carrying a risk of significant hydrothorax, particularly on the right side and in nonobese patients.