First prize (tie) - Hemorrhage following percutaneous renal surgery: Characterization of angiographic findings

Purpose: Percutaneous surgery is an established approach to a spectrum of renal pathology, and hemorrhage is the most concerning complication of this technique. We determined the frequency of postoperative hemorrhage requiring selective angioembolization (SAE), the efficacy of this approach, and characterized the angiographic findings. Methods: We reviewed our database of 4695 patients who underwent percutaneous renal surgery and identified patients requiring SAE for postoperative hemorrhage. Angiographic findings were recorded and efficacy of SAE documented. Results: Patients undergoing percutaneous stone extraction (PSE; 3685), percutaneous antegrade endopyelotomy (PAE; 850), and upper-tract transitional cell carcinoma (UTTCC) resection (160) were reviewed. We identified 57 patients requiring SAE (1.2%) who underwent 44 PSEs (77.2%), 7 PAEs (12.3%), and 6 UTTCC resections (10.5%). This represented 1.2%, 0.8%, and 3.2% of all PSE, PAE, and UTTCC resections, respectively. Angiography revealed treatable lesions in 94.7% of patients. Overall, 64 angiographic findings were encountered including 30 pseudoaneurysms (53% of patients, 47% of findings), 14 arteriovenous fistulas (AVFs) (25% of patients, 22% of findings), and 14 instances of contrast extravasation (25% of patients, 22% of findings). Two arterial dissections and one instance each of a hypervascular area, a vascular "cut-off" sign, and a fistula between an artery and the percutaneous tract were identified. One bleeding vessel identified at the base of a UTTCC resection was not amenable to embolization. Ten patients (17.5%) had ≥1 angiographic finding. Three patients (5.3%) had no angiographic findings to account for hemorrhage. No angioembolization-related complications occurred. Complete resolution of bleeding was observed in 54 patients (95%). Conclusions: Major hemorrhage requiring intervention after percutaneous renal surgery is uncommon. The most common angiographic finding is arterial pseudoaneurysm, followed by arteriovenous fistula, and contrast extravasation. In 95% of cases angiography reveals a demonstrable and treatable etiology. This strongly supports the first-line use of angiography for intractable bleeding in this setting.