Evaluation of a Novel Synthetic Sealant for Inhibition of Cardiac Adhesions and Clinical Experience in Cardiac Surgery Procedures

Abstract

Background: Pericardial adhesions subject patients requiring reoperation to potential injuries to the heart, great vessels, and cardiac grafts during the re-sternotomy. These adhesions can severely complicate re-operations by making re-entry hazardous, impeding orientation and visibility, increasing the amount of blood loss, and prolonging the operation time. The efficacy of an in situ-forming polyethylene glycol (PEG) material, CoSeal^® surgical sealant (CoSeal^®), for inhibiting cardiac adhesions in an animal model is reported. It is currently estimated that 10-20% of patients undergoing aortic valve replacement and coronary artery bypass grafting (CABG) will require a second operation later in their lives. Successful clinical experience using CoSeal^® for sealing suture lines of the aorta and CABGs with the data reported here suggest that CoSeal^® may have multiple applications in cardiac surgery.

Methods: In rabbits, a sternotomy and pericardiotomy were performed to expose the heart and the epicardium of the left ventricular surface. The epicardium was abraded for five minutes with dry gauze and cotton to develop punctate bleeding. In treated animals, CoSeal^® or Tissucol^® was applied directly to the abraded bleeding epicardium while retracting the pericardium. The pericardium was released, and the material over-sprayed to the cut edges of the pericardium. No material was applied in control animals.

Results: At necropsy, CoSeal^® was found to significantly reduce the formation of adhesions, the tenacity of the adhesions, and the percent of the abraded site with adhesions as compared to surgical control and Tissucol^®. Tissucol^® showed no significant difference from the surgical control in any adhesion parameter. CoSeal^® treated hearts showed re-establishment of the mesothelial layer and tissue morphology similar to a normal un-operated heart. During the clinical cardiac procedures, CoSeal^® was easily mixed and applied to the suture lines of the aorta and coronary artery grafts. No bleeding was found at the suture lines.

Conclusions: In the rabbit cardiac adhesion model, CoSeal^® significantly reduced the formation of adhesions as compared to surgical control and Tissucol^®, and demonstrated good biocompatibility. In CoSeal^® treated patients undergoing cardiopulmonary bypass or vessel repair, sealing was achieved comparable to previous cases using Tissucol^® fibrin sealant. CoSeal^® effectively sealed the suture lines of the aorta and coronary artery bypass grafts.