Surgical management of pediatric renin-mediated hypertension secondary to renal artery occlusive disease and abdominal aortic coarctation

INTRODUCTION: Renovascular hypertension (RVH) associated with renal artery and abdominal aortic narrowings is the third most common cause of pediatric hypertension. Untreated children may experience major cardiopulmonary complications, stroke, renal failure and death. The impetus of this study was to describe the increasingly complex surgical practice for such patients with an emphasis on anatomic phenotype and contemporary outcomes following surgical management, as a means of identifying those factors responsible for persistent or recurrent hypertension necessitating reoperation. METHODS: A retrospective analysis was performed of consecutive pediatric patients with RVH undergoing open surgical procedures at the University of Michigan from 1991 to 2017. Anatomic phenotype and patient risk factors were analyzed to predict outcomes regarding blood pressure control and the need for secondary operations using ordered and binomial logistic multinomial regression model, respectively. RESULTS: One hundred sixty-nine children (76 girls, 93 boys) underwent primary index operations at a median age of 8.3 years. Thirty-one children (18%) had neurofibromatosis type I, 76 (45%) had abdominal aortic coarctations, and 28 (17%) had a single functioning kidney. Prior to treatment at the University of Michigan, 51 children experienced failed previous open operations (15) or endovascular interventions (36) for RVH at other institutions. Primary surgical interventions (342) included: main renal artery (136) and segmental renal artery (10) aortic reimplantation; renal artery bypass (55); segmental renal artery embolization (10); renal artery patch angioplasty (8); resection with reanastomosis (4); partial or total nephrectomy (25). Non-renal artery procedures included: patch aortoplasty (32), aorto-aortic bypass (32), and splanchnic arterial revascularization (30). Nine patients required reoperation in the early post-operative period. During a mean follow-up of 49 months, secondary interventions were required in 35 children (21%) including both open surgical (37) and endovascular (14) interventions. Remedial interventions to preserve primary renal artery patency or a nephrectomy if such was impossible, were required in 22 children (13%). The remaining secondary procedures were performed to treat previously untreated disease that became clinically evident during follow-up. Age at operation and abdominal aortic coarctation were independent predictors for reoperation. The overall experience revealed hypertension to be cured in 74 children (44%), improved in 78 (46%) and unchanged in 17 (10%). Children undergoing remedial operations were less likely (33%) to be cured of hypertension. There was no perioperative mortality or renal insufficiency requiring dialysis following either primary or secondary interventions. CONCLUSIONS: Contemporary surgical treatment of pediatric RVH provides a sustainable overall benefit to 90% of children. Interventions in the very young (ie