OBJECTIVE The optimal method of operative management of complex branch renal artery aneurysms (RAAs) remains unclear, with recent reports predominantly espousing endovascular and ex vivo repair. We sought to determine the long-term outcome of RAA repair performed with autogenous in situ techniques. METHODS This was a cohort study of patients undergoing surgical repair of RAAs identified from our prospective vascular division registry (1984-2009). RESULTS Twenty-six RAAs were repaired in 24 patients (17 women, 7 men; mean age, 52 ± 16 years). Mean size was 2.3 ± 0.7 cm (range, 0.7-4.0 cm). Twenty RAAs were repaired based on size and six for hypertension alone. Multiple RAAs were present in 13 patients (54%). Associated conditions included hypertension in 24 (100%), fibromuscular dysplasia in 6 (25%), coexistent renal artery stenosis in 6 (25%), and aortic aneurysm in 3 (12.5%). Reconstruction of first- or second-order branches was required in 25 RAAs (96%). In situ techniques were used in 22 repairs and included resection combined with autogenous vein bypass and interposition in 11, primary anastomosis to conjoined outflow vessels in 3, and aortic reimplantation in 2. Aneurysmorrhaphy was combined with vein patch angioplasty in 6, exclusion in 2, tailored primary closure in 1, and autogenous bypass in 1. Four patients underwent ex vivo reconstruction. Perioperative mortality was 0% and morbidity was 11.5%, including one nephrectomy during ex vivo repair for immediate thrombosis. Renal function was preserved (preoperative creatinine, 0.94 ± 0.3 vs postoperative creatinine 1.06 ± 0.4 mg/dL; P = .11). Systolic (SBP) and diastolic blood pressure (DBP) control improved after operation: preoperative SBP 142 ± 18 vs postoperative SBP 130 ± 15 mm Hg (P = .007) and preoperative DBP 86 ± 14 vs postoperative DBP 78 ± 10 mm Hg (P = .01). Long-term patency was evaluated in 18 reconstructions (69%) by duplex imaging or contrast radiography at an average long-term follow-up of 99 months (range, 1-300 months) and was 94%. Five-year freedom from rupture and survival by the Kaplan-Meier method was 100%. CONCLUSIONS In situ techniques allow repair of complex RAAs involving branch vessels with minimal morbidity, improved blood pressure control, and maintenance of renal function. This operative approach further provides excellent long-term patency and survival in this relatively young patient population.