Can Redo Sternotomy Become as Easy as First-Time Sternal Opening?

Abstract

Injury to vital vascular and cardiac structures is a redoubtable complication associated with redo sternotomy. This may be one reason why the pericardium should be closed whenever possible at least over the great vessels and the cranial part of the heart in every patient. This is of particular importance in those patients in whom a redo surgery may be expected (congenital surgery, valvular reconstruction and/or implantation of tissue valves, implantation of left ventricular device as bridging therapy). In many patients, however, a complete closure of the pericardium is not possible because of the intraoperative swelling of the heart or just because the necessary filling of the heart at the end of the procedure precludes a tension-free pericardial closure. In these cases, implantation of a pericardial or artificial membrane as pericardial replacement may be a wise decision. Independently of the presence of a membrane or not, computed tomography or magnetic resonance imaging is of great value before reopening the sternum to estimate the proximity of the posterior surface of the sternum to the most important cardiovascular structures (right ventricle, ascending aorta, innominate vein) or previous implants (pulmonary conduit or homograft, and saphenous vein grafts or internal thoracic artery in case of previous coronary artery bypass grafting). Previous subcutaneous implantation of different pericardial replacement patches in a porcine model has shown the following results: CorMatrix (CorMatrix Cardiovascular, Inc, Sunnyvale, CA) showed gradual and consistent patch resorption and subsiding inflammatory and fibrosis process. Full scaffold degradation and replacement by mild fibrosis and subcutaneous tissue were seen by 1 year. Xenopericardial patches remained intact, and the initially severe inflammatory and fibrotic reactions reduced gradually to moderate fibrosis and chronic inflammation. Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) showed foreign body reaction.1Mosala Nezhad Z. Poncelet A. Fervaille C. Gianello P. Comparing the host reaction to CorMatrix and different patch materials implanted subcutaneously in growing pigs.Thorac Cardiovasc Surg. 2019; 67: 44-49Crossref PubMed Scopus (6) Google Scholar The GoreTex polytetrafluoroethylene membrane has most probably been the most frequently implanted pericardial substitute so far. Its protective effects in case of redo sternotomy are recognized, but the adhesions with the epicardial surfaces may be strong. Among more recent alternatives, CorMatrix has been described as an interesting recellularized scaffold but the results among different studies were somewhat conflicting,2Bustamante-Munguira J. Serrano R. Figuerola-Tekerina A. et al.Is CorMatrix really a recellularization scaffold as a pericardial substitute in cardiac surgery?.J Cardiovasc Surg (Torino). 2018; 59: 142-143PubMed Google Scholar whereas bovine pericardium subjected to a novel anticalcification tissue-engineering process (CardioCel, LeMaitre Vascular, Inc, Burlington, MA) seems promising: A neointimal layer of varying thickness developed on the visceral surface of 5 CardioCel explants with endothelialization of the longest duration explant.3Prabhu S. Armes J.E. Bell D. et al.Histologic evaluation of explanted tisue-engineered bovine pericardium (CardioCel).Semin Thorac Cardiovasc Surg. 2017; 29: 356-363Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar In this issue of The Annals of Thoracic Surgery, Hu and coauthors4Hu C. Tang F. Wu Q. et al.Novel trilaminar polymeric anti-adhesion membrane prevents postoperative pericardial adhesion.Ann Thorac Surg. 2021; 111: 184-190Abstract Full Text Full Text PDF Scopus (8) Google Scholar from Beijing have to be congratulated for another important step—that is, a novel trilaminar membrane that was compared (mainly adhesive effects) to the well-known expanded polytetrafluoroethylene membrane in an animal study. The goal of this new membrane is to minimize post-sternotomy adhesions (through the resorbable components) while maintaining a permanent physical barrier (through the middle layer). All layers contain a novel polymer made of polyvinyl alcohol and carboxymethylcellulose. Because the generation of adhesions and granulation tissue are most active 5 to 7 days after implantation and adhesions become stable approximately from day 14 post implantation, the new material resorbs rapidly after implantation during initial surgery. This might be of particular interest if, for any reason, a reexploration becomes necessary during the early follow-up period. Looking at the microscopic specimen in animals, every cardiac surgeon may be eager to have this new pericardial replacement membrane in their fingers as soon as available on the market. Novel Trilaminar Polymeric Antiadhesion Membrane Prevents Postoperative Pericardial AdhesionThe Annals of Thoracic SurgeryVol. 111Issue 1PreviewPostoperative pericardial adhesion formation is a prominent cause of morbidity and death in cardiovascular surgery, but there is still no ideal prevention method, especially in redo cases. This study investigated a novel antiadhesion trilaminar polymeric film compared with the Gore PRECLUDE Pericardial Membrane (W. L. Gore & Associates, Flagstaff, AZ) and a negative control. Full-Text PDF