Apicoaortic Conduit: A Simple Solution to a Difficult Problem

Abstract

Apicoaortic conduit is a nonanatomic method of providing forward flow from the left ventricle. It is used as an alternative to aortic valve replacement in patients with comorbid factors that preclude a safe approach via median sternotomy. Our patient had undergone aortic and mitral valve replacements with bileaflet mechanical prostheses. After almost a decade, he started to experience recurrent episodes of congestive heart failure requiring hospitalization. Preoperative transesophageal echocardiography and computed tomography of the chest were done for evaluation. The 21-mm Carbomedics bileaflet aortic prosthesis (Sorin Group USA Inc, Arvada, CO) provided an effective orifice area index of 0.58 cm2/m2, leading to severe patient-prosthesis mismatch.1 A compounding factor was significant subvalvar stenosis (Panel A, arrows) due to the hypertrophied small left ventricle and the abnormal axis of the mechanical mitral valve (Panel A, asterisk). The ascending aorta measured 2.5 cm at the sinotubular junction, which is also smaller than normal (2.1-3.4 cm).2 The small hypertrophied left ventricle (LV) (Panel A, arrows) had a high end-diastolic pressure as demonstrated by the dilated left atrium (Panel A, LA). The multiple levels of left ventricular outflow tract obstruction made a corrective procedure via median sternotomy very high risk. Because of the abnormal placement of the mitral valve (Panel A, asterisk), we did not feel that we would be able to relieve the subvalvar stenosis even with myectomy. An apicoaortic conduit (Panel C, arrow) was constructed between the left ventricular apex (LVA) and the descending thoracic aorta (DTA) via a left thoracotomy. Normothermic cardiopulmonary bypass was achieved by cannulation of the left common femoral artery and vein. The left ventricle was small and hypertrophied with a very small cavity. Two separate pieces of a 16-mm Dacron tube graft (Medtronic, Inc, Minneapolis, MN) were anastomosed to the left ventricular apex (LVA) and the descending thoracic aorta (DTA) (Panel B, white arrows). A 20-mm Dacron graft was interposed between these 2 grafts (Panel B, gray arrow), and a 17-mm bileaflet mechanical valve (St. Jude Medical, St. Paul, MN) was interposed between these conduits. Hence, the combined effective orifice area index was 1.11 cm2/m2. The patient experienced marked symptomatic improvement at dismissal and was counseled regarding strict adherence to therapeutic anticoagulation, as he had 3 mechanical valves in situ. We demonstrate that this procedure is useful for the management of patients with complex left ventricular outflow tract obstruction. It avoids the high risks involved in repeated median sternotomy approach.