IP237 Natural History and Management of Renal Artery Aneurysms in a Single Tertiary Referral Center

Abstract

Although renal artery aneurysms (RAA) are uncommon, several large reports have been published indicating their benign natural history. The objective of our study was to review our own single-center experience managing this disease entity. A retrospective review of the Yale radiology database from January 1999 to December 2016 was performed. Only patients with RAA and a computed tomography (CT) scan of the abdomen were selected for review. Patient demographics, aneurysm characteristics, management, postoperative complications, and follow-up data were collected. We identified 241 patients (147 females [61%]) with 259 RAAs. Mean age was 69 years (range, 35-100 years). RAA was as an incidental finding 236 patients (98%). On CT, aneurysms were solitary in 224 (86%) and right sided in 159 (61%), and 64 patients (27%) had aneurysms elsewhere. The breakdown of RAA by location was as follows: renal bifurcation in 84 (32%), renal pelvis in 77 (30%), distal renal artery in 58 (22%), midrenal artery in 34 (13%), and proximal renal artery in 6 (2%). Only five patients were symptomatic and underwent operative repair (OR); all others were monitored with CT without an operation (NOR). Symptoms included flank pain in four and uncontrolled hypertension in one. The mean overall diameter of the RAAs was 1.22 ± 0.49 cm. The diameter of OR and NOR was 1.84 ± 0.55 cm and 1.21 ± 0.48 cm, respectively (P = .002). OR included four coil embolizations and one open resection. There were no renal function changes in any of these patients after the operation and no other complications. Mean follow-up was 41 ± 35 months for patients in the NOR group; 18 of these RAAs were >2 cm, and none ruptured. On multivariate regression analysis, female gender (P = .0001), smoking history (P = .00007), the presence of RAA calcification (P = .05), left-sided RAA (P = .03), and main renal artery location (P = .03) were inversely related to growth, whereas a history of hypertension was directly related to increased growth rate (P = .01). The mean growth rate for RAA was 0.017 ± 0.052 cm/y (Fig). RAA tend to have a benign natural history. Although, previous reports have not identified any factors that contribute to RAA growth, we observed that RAA calcification, location, gender, smoking history, and hypertension may impact growth rates. No ruptures were observed. Operative repair at our institution was rare with no morbidity. Observation of RAA over time seems feasible in an asymptomatic patient.