CARDIOPULMONARY BYPASS

There has been a recent renewed interest in certain aspects of cardiopulmonary bypass employing extracorporeal circulation. Several areas have received special attention. Among these is the institution of extracorporeal circulation using a percutaneous technique for circulatory assistance during high-risk percutaneous transluminal coronary angioplasty. A national registry has been established to review and monitor results using this percutaneous technique. Several recent developments in the delivery of cardioplegia during ischemic arrest have stimulated investigative efforts. In particular, the delivery of cardioplegia in a retrograde manner through the coronary sinus has proved an effective and useful adjunct to myocardial protection during cardiopulmonary bypass with extracorporeal circulation. A newer investigative technique employing only warm cardioplegia delivered primarily through the retrograde coronary sinus route seems to offer some promise in providing optimal myocardial protection while minimizing hemorrhagic complications and other cold-induced myocardial injury. Because of concerns regarding blood transfusion-related communicable disease (eg, acquired immune deficiency syndrome and non-A, non-B hepatitis), there has been increasing research effort into postoperative hemorrhage related to cardiopulmonary bypass with extracorporeal circulation. Specifically, various drugs that may serve as hemostatic adjuncts have been investigated extensively. These drugs include aprotinin and desmopressin acetate. Likewise, several studies have evaluated other drugs (mainly aspirin) that have a negative influence on postoperative hemostatis. Additionally, there has been continued research interest in the activation of the inflammatory system during cardiopulmonary bypass. Since activation of the various inflammatory mediators seems to be related to postoperative organ system dysfunction following extracorporeal circulation, it is possible that modification of the inflammatory response may be associated with decreased organ dysfunction following cardiac procedures that employ extracorporeal circulation. This review attempts to focus on recent developments related to extracorporeal circulation, with emphasis placed not only on advances in clinical practice that may have an immediate influence on operative outcome but also on newer laboratory studies that will have an impact in the future.