Contemporary Outcomes for Branch Renal Artery Repair.

INTRODUCTION: The purpose of this study is to provide an updated description of demographics, technical details and clinical outcomes of 101 consecutive branch renal artery repairs in 98 patients using cold perfusion.

METHODS: Single institution, retrospective analysis branch renal artery reconstructions performed between 1987 and 2019.

RESULTS: Patients were predominantly Caucasian (80.6%) women (74.5%) with mean age of 46.8 ± 15.3 years. Mean pre-operative systolic and diastolic blood pressure were 170.4 ± 33.0 mm Hg and 99.2 ± 19.9 mm Hg requiring a mean of 1.6 ± 1.1 anti-hypertensive medications. Estimated glomerular filtration rate (eGFR) was 84.0 ± 25.3 mL/min. Most patients (90.2%) were not diabetic and never smokers (68%). Treated pathology included aneurysm (87.4%) and stenosis (23.3%) with histology demonstrating fibromuscular dysplasia (44.4%), dissection (5.1%), and degenerative not otherwise specified (50.5%). The right renal arteries were most frequently treated (44.2%) with a mean of 3.1 ± 1.5 branches involved. Reconstruction was accomplished using bypass in 90.3% of cases employing aortic inflow in 92.7% and saphenous vein conduit in 92%. Branch vessels served as outflow in 96.9% and syndactylization of branches was used to reduce number of distal anastomoses in 45.3% of repairs. Mean number of distal anastomoses was 1.5 ± 0.9. Post-operatively, mean systolic blood pressure improved to 137.9 ± 20.8 mm Hg (mean decrease 30.5 ± 32.8 mmHg; P<.0001) and diastolic blood pressure improved to 78.4 ± 12.7 mm Hg (mean decrease 20.1 ± 20.7 mmHg; P<.0001) with patients requiring a mean of 1.4 ± 1.0 antihypertensive medications (mean decrease 0.2 ±1.0 meds; P=0.048). Postoperative eGFR was 89.1 mL/min (mean increase 4.1 mL/min; P=0.08). Mean length of stay was 9.0 ± 5.8 days and 96.1% of patients were discharged home. Mortality rate was 1% (one patient with liver failure) and the major morbidity rate was 15%. There were five infectious complications (pneumonia, clostridium difficile, and wound infection) and five patients required return to the operating room (one for nephrectomy, one for bleeding, two for thrombosis, and one for second trimester pregnancy loss requiring dilation and curettage and splenectomy). One patient required temporary dialysis due to graft thrombosis. Two patients developed arrhythmias. No patients suffered myocardial infarction, stroke, or limb loss. After 30 days, follow-up data were available for 82 bypasses. At this time, three reconstructions were no longer patent. Intervention was required to retain patency for five bypasses. After one year, patency data were available for 61 bypasses and five were no longer patent. Of the five grafts with loss of patency, two underwent intervention in attempt to maintain patency which subsequently failed.

CONCLUSIONS: Repair of renal artery pathology involving the branches can be performed with short- and long-term technical success and significant prospect of reducing elevated blood pressure. The operations required to fully address the presenting pathology are often quite complex involving multiple distal anastomoses and consolidation of small secondary branches. The procedure carries a small but significant risk of major morbidity and mortality.