Does imaging modality used for percutaneous renal access make a difference? A matched case analysis.

Objective: To assess perioperative outcomes of percutaneous nephrolithotomy (PCNL) using ultrasound or fluoroscopic guidance for percutaneous access. Methods: A prospectively collected international Clinical Research Office of the Endourological Society (CROES) database containing 5806 patients treated with PCNL was used for the study. Patients were divided into two groups based on the methods of percutaneous access: ultrasound versus fluoroscopy. Patient characteristics, operative data, and postoperative outcomes were compared. Results: Percutaneous access was obtained using ultrasound guidance only in 453 patients (13.7%) and fluoroscopic guidance only in 2853 patients (86.3%). Comparisons were performed on a matched sample with 453 patients in each group. Frequency and pattern of Clavien complications did not differ between groups (p = 0.333). However, postoperative hemorrhage and transfusions were significantly higher in the fluoroscopy group: 6.0 v 13.1% (p = 0.001) and 3.8 v 11.1% (p = 0.001), respectively. The mean access sheath size was significantly greater in the fluoroscopy group (22.6 v 29.5F; p < 0.001). Multivariate analysis showed that when compared with an access sheath <= 18F, larger access sheaths of 24-26F were associated with 3.04 times increased odds of bleeding and access sheaths of 27-30F were associated with 4.91 times increased odds of bleeding (p < 0.05). Multiple renal punctures were associated with a 2.6 odds of bleeding. There were no significant differences in stone-free rates classified by the imaging method used to check treatment success. However, mean hospitalization was significantly longer in the ultrasound group (5.3 v 3.5 days; p < 0.001). Conclusions: On univariate analysis, fluoroscopic-guided percutaneous access was found to be associated with a higher incidence of hemorrhage. However, on multivariate analysis, this was found to be related to a greater access sheath size (>= 27F) and multiple punctures. Prospective randomized trials are needed to clarify this issue.