INTRODUCTION:
Adhesions are fibrotic connections resulting from tissue trauma and subsequent inflammation and ischemia during surgery. While adhesions are germane to many forms of surgery, postoperative pericardial adhesions (PPAs) are an important clinical problem in cardiac surgery. The resulting obliteration of tissue planes puts vital structures at risk for injury during re-operation and sternal re-entry, particularly the aorta, right ventricle, and right atrium. At least 10% of cardiac surgeries require re-operation.1 The incidence of re-entry injuries in these procedures is relatively low at approximately 3%; however, they are associated with almost three times greater mortality rates.2 PPAs hinder dissection and visibility too, thereby increasing operative time, cardiopulmonary bypass time, and blood loss. The increased morbidity, mortality, and economic costs posed by PPAs during re-operation ultimately place the patient at risk and pose an undue burden on the surgical team.
In an effort to improve outcomes, barriers have been developed to limit adhesion formation. These adhesion barriers have now been used in cardiac surgery for over four decades and can be divided into two categories: nonresorbable and bioresorbable.3Nonresorbable barriers include both prosthetic and/or xenograft materials while bioresorbable barriers include pharmacologic agents and/or resorbable membranes.3, 4 Nonresorbable barriers create indefinite physical separation between tissue planes and provide a readily discernable area at re-operation. Nonresorbable barriers were the first type of products developed to prevent PPAs. However, bioresorbable barriers have recently been developed more and have garnered interest among both patients and surgeons. Bioresorbable barriers confer a potential relative benefit by not leaving a foreign body in place for long periods of time and not requiring re-operation for barrier removal. The only licensed adjuncts for PPA prevention at this point in time are either nonresorbable or bioresorbable physical barriers.5 Pharmacotherapy agents that act at the molecular level have yet to be identified. Although numerous products currently exist, a perfect solution to PPAs has yet to be identified.
Research efforts analyzing adhesion barriers have historically focused on abdominal and gynecologic surgery.6, 7, 8, 9Limited data currently exists with respect to cardiac surgery. Recent systematic review have assessed adhesion and particularly PPA formation and prevention methods.3, 5 However, none have compared the efficacy and safety of specific adhesion barriers for preventing PPAs in the clinical setting. The study presented here addresses this knowledge gap by providing the first major systematic review of adhesion barriers in cardiac surgery.