An automated coring and apical connector insertion device facilitates aortic valve bypass (apicoaortic conduit) surgery: preclinical experience in a chronic ovine model

BACKGROUND AND AIM OF THE STUDY: Aortic valve bypass (AVB, apicoaortic conduit) surgery is an alternative treatment for high-risk patients with aortic stenosis (AS). An automated coring and connector insertion device designed to simplify the apical AVB anastomosis has been developed. The applicator consists of a toroidal shaft-mounted balloon, an integrated circular coring knife, and a stented apical connector supporting a Dacron graft. In this way, apical myocardial coring, connector insertion and core removal may be automated.

METHODS: AVB was performed without cardiopulmonary bypass in eight sheep. A conduit containing a porcine valve was anastomosed to the descending aorta using a partial occlusion clamp. The applicator was used to insert the apical connector, and the connector and conduit were joined with a quick-connector. The descending aorta was occluded proximal to the distal anastomosis to simulate AS. Gradients across the conduit were measured after implantation, and one month later at sacrifice.

RESULTS: All AVB implants were performed successfully. The median blood loss was 50 ml (IQR: 13- 98 ml). The median connector implantation time was 29 s, and the peak gradients across the conduit early and at 30 days after AVB were 5.2 +/- 2.6 mmHg and 2.7 +/- 1.4 mmHg, respectively. One animal died of hemothorax at 24 h after surgery, but all remaining animals survived and gained weight. Gross and histopathologic assessments demonstrated widely patent conduits and normal brain histology in all animals.

CONCLUSION: The applicator facilitated the safe and expeditious performance of AVB surgery. The clinical use of this device will improve the safety and increase the adoption of this beating-heart therapy for AS.