Recovery model for minimally invasive central cannulation, cardiopulmonary bypass, and cardioplegic arrest in quadrupeds.

Abstract

Objectives: Sternotomy is rarely performed for veterinary therapeutic or recovery models in quadrupeds because of difficulties with breathing, ambulation, and pain control. Central cannulation for cardiopulmonary bypass (CPB) is infrequent and typically performed through full thoracotomies. Experienced clinical surgeons and perfusionists should provide guidance for new therapeutic interventions and translational research. We sought to develop, validate, and detail a contemporary model for minimally-invasive central cannulation, CPB, and cardioplegic arrest. Methods: After induction of anesthesia and sterile preparation, a right second-interspace parasternal mini-thoracotomy was performed, the ascending aorta was cannulated using Seldinger technique, and a cardioplegia needle was placed. A dual-stage cannula was introduced through the right atrial appendage and CPB commenced. The aorta was clamped and Buckberg 4:1 induction cardioplegia was administered. Arrest was maintained for 30 minutes. CPB was discontinued after 2 hours and the great vessels were decannulated. Hemostasis was achieved and the wound was closed. Initial recovery was accomplished in intensive care with subsequent transfer to the vivarium.Results: Ten consecutive Yorkshire swine (45 ± 5 kg) were minimally invasively placed on CPB including cardioplegic arrest using central cannulation through a right parasternal mini-thoracotomy. There was no operative or late mortality. Morbidity appeared minimal. Planned euthanasia and scheduled necropsy were performed to exclude clinically-occult major complications. None were identified. Following initial supervision, veterinary and resident surgeons completed the procedures autonomously with excellent results.Conclusion: The described protocols should facilitate safe veterinary cardiac surgical care and humane translational research.