Ethylene Vinyl Alcohol Copolymer Embolization for Acute Renal Hemorrhage: Initial Experience in 24 Cases.

OBJECTIVE. The purpose of this study was to assess the efficacy and safety of ethylene vinyl alcohol (EVOH) copolymer (Onyx, Medtronic) for embolization for acute renal hemorrhage. MATERIALS AND METHODS. Between October 2006 and June 2018, 24 consecutive patients were treated by embolization with EVOH copolymer for acute renal hemorrhage at Hôpital Bichat-Claude-Bernard. CT angiography was performed in all patients before treatment. Technical success was defined as the complete occlusion of the bleeding artery on final renal angiogram. Clinical success was defined as the absence of rebleeding after embolization. Complications mid procedure, infarcted renal area on final angiogram, and renal function 1 week after embolization were retrospectively analyzed. RESULTS. Active bleeding was observed in all cases. The causes of acute renal hemorrhage were iatrogenic in 12 patients, vascular malformation in four patients, renal tumor in four patients, and unknown in four patients. EVOH copolymer was the sole embolic agent used in 16 patients. In eight patients, EVOH copolymer was used after persistent bleeding after embolization with coils. Technical and clinical success rates were 100%. No patient required surgery or new embolization during a mean follow-up period of 35 months (range, 6-86 months). No serious complications were attributable to EVOH copolymer. The mean infarcted renal area was 10% (range, 5-30%). Renal function, available for 16 (67%) patients, was not altered 1 week after embolization. CONCLUSION. EVOH copolymer is safe and effective for embolization of acute renal hemorrhage, either as a first-line embolic agent or after failure of coil embolization.