Reduction of postoperative hypothermia with a new warming device: a prospective randomized study in off-pump coronary artery surgery.

Hypothermia has been used for decades in cardiac surgery to limit the ischemic insult to the heart. With the diffusion of off-pump coronary artery surgery, the practice of arresting and cooling the heart has been abandoned. At University of Miami Miller School of Medicine, we tested a new warming device by performing a prospective study in which 50 patients were randomized to either the use of the Kimberly-Clark warming system or to standard methods of control of body temperature. The two groups were compared in terms of core body temperature (CBT), intra- and postoperative blood loss, blood products transfusions, extubation time, intensive care unit (ICU) and hospital length of stay and incidence of infections. Five patients in the control group and 0 patients in the study group dropped their CBT below 35 degrees C during the operation (P<0.01). Total blood loss, measured in terms of cell-saver and chest tube drainage, was 27 % and 14 % less for the study group (P<0.01). Hospital length of stay was 1.2 day less in the study group (P<0.01). The Kimberly-Clark Patient Warming System allowed for better control of core body temperature during off pump coronary artery bypass surgery compared to traditional techniques. This translated in less intra and postoperative blood loss and shorter hospital length of stay. Other advantages, such as decreased blood-products transfusions, decreased incidence of infections, decreased ICU length of stay and overall reduction of costs might be evident on larger study groups.

The role of beating heart coronary artery bypass grafting in the current era: a point of view.

Despite coronary artery revascularization on the beating heart was originally introduced in the 1960's, its further development was halted for several decades by advances in medical technology and by the development of the extracorporeal circulation. It is only in recent years that coronary artery bypass grafting on the beating heart has gained a secure role in the armamentarium of cardiac surgeons, mainly as a result of the popularization of new techniques of coronary exposure and stabilization. In later years, the expansion of interventional cardiology and the refinement of catheter-based techniques for treating coronary artery disease have corresponded to a substantial decline in the overall number of patients referred for surgery. Additionally, more and more patients have extensive disease and concomitant risk factors. These factors have made the future of coronary artery surgery uncertain. As these trends are likely to persist, and probably become more prominent in the future, it is essential for surgeons to embrace changes that may lead to improved surgical outcomes after coronary revascularization. In this article the authors review some of the aspects that have contributed to the popularization of off-pump coronary artery bypass and speculate on the importance of embracing innovative techniques in the field of coronary artery surgery.

Transmitral endoventricular repair of left ventricular pseudoaneurysm following mitral valve replacement.

Left ventricular (LV) pseudoaneurysm is a rare but serious complication of mitral valve replacement and is usually the consequence of atrioventricular separation. Although there may be a role for nonoperative treatment in the presence of a small false aneurysm and in the absence of paravalvular leak, the presence of a large false aneurysm usually mandates surgical intervention. This may be hazardous in patients with concomitant LV dysfunction. We report a case of a patient who presented with a large LV pseudoaneurysm following numerous attempts of mitral valve replacements for a variety of reasons, including endocarditis. Some of the technical details of aneurysm repair and aspects of myocardial protection are discussed. In our patient, avoidance of cardioplegic arrest may have contributed to the successful outcome.

"H" graft from the right internal mammary artery to the left anterior descending coronary artery: an alternative strategy in reoperative grafting of the LAD territory.

Reoperative grafting of the left anterior descending (LAD) coronary artery or its diagonal branches can be accomplished through a left anterior small thoracotomy (LAST) on the beating heart using the left internal mammary artery (LIMA) as a conduit. Patients in whom the LIMA has been used previously, however, are generally excluded from this approach unless an alternative technique is utilized. We describe a new technique applicable to these patients that consists of grafting the LAD through a LAST approach and connecting the graft to the right internal mammary artery (RIMA).

Surgical strategy for repair of large pseudoaneurysms of the aortic isthmus.

Resection of unusually large pseudoaneurysms of the aortic isthmus is complex, and involves various strategies of cardiopulmonary bypass (CPB), cerebral and spinal cord protection. We report on a patient with a giant pseudoaneurysm of the distal arch and proximal descending aorta, in whom cannulation of the femoral artery was unfeasible. Instead, the right axillary artery and the left femoral vein were cannulated. This technique allowed to perform a left anterolateral thoracotomy with the patient already on CPB and hypothermic, and to shorten the duration of hypothermic circulatory arrest.

Does avoidance of cardiopulmonary bypass decrease the incidence of stroke in diabetics undergoing coronary surgery?

BACKGROUND: The adverse effects of diabetes mellitus on the coronary circulation and the higher incidence of cardiovascular events in diabetic patients are well documented [Johnson 1982]. Improvements in myocardial protection, revascularization techniques, and anesthetic management have had favorable impacts on coronary artery bypass grafting (CABG) outcome in diabetic patients. Despite that, diabetic patients are significantly more likely to have a prior history of myocardial infarction, congestive heart failure, peripheral vascular disease, and hypertension, as well as having a significantly greater baseline serum creatinine. The aim of our study was to record, compare, and analyze the stroke rate among patients with a history of preoperative diabetes undergoing "off-pump" CABG (OPCAB) with conventional cardiopulmonary bypass (CPB) CABG to determine whether the stroke rate in this higher risk population could be decreased by off-pump techniques. METHODS: The records of 1,227 patients with a pre-operative history of diabetes undergoing conventional CABG (973 patients, 79.3%) using cardiopulmonary bypass and off-pump CABG 254 (20.7%) were analyzed from 1995 through 1999. There were no differences in age, sex, or elective/urgent status of patients. Preoperative risk factors (gender distribution, carotid disease, ejection fraction, CHF, hypertension, previous MI) were identical in both groups. The goal of the operations were complete revascularization, which was achieved via median sternotomy in both groups. RESULTS: Our reported series reveals a stroke rate of 3.6% in the CPB group and 1.2% in the off-pump group. This evidence alone was not statistically significant, but two other high-risk criteria for stroke, re-do CABG and calcified aortas, revealed that the off-pump series had a higher percentage of each (26.4% redos in off-pump vs. 8.7% CPB redos, p < 0.005; 7.1% calcified aorta cases in the off-pump group vs. 2.9% in the CPB group, p < 0.004). The threefold reduction in stroke may be clinically significant in light of the higher-risk profile of the off-pump group. The limitations of this study are that it was retrospective, there were a small number of events, and different surgeons were involved in the two different approaches to these patients. CONCLUSIONS: Improvements in myocardial protection, revascularization techniques, and anesthetic management have made significant, favorable impacts on CABG outcome in diabetic patients. New diagnostic and therapeutic strategies must be developed to lessen the medical and economic implications of stroke. A larger series or a more effective way of analyzing preoperative risk may well have shown a statistically significant difference in the stroke incidence given the differences in preoperative risk factors/stroke predictors. Until such advances occur, a threefold reduction of stroke incidence using OPCAB certainly makes this technique a favorable one for high-risk diabetics requiring coronary revascularization.

Thoracic epidural anesthesia for coronary bypass via left anterior thoracotomy in the conscious patient.

Cardiac surgery is perceived to be maximally invasive and fraught with complications. Secondary to this, cardiothoracic surgeons have been refining traditional techniques to minimize their invasive nature. Epidural anesthesia has been utilized safely and effectively for numerous surgical procedures to reduce the associated morbidity. In hopes of achieving a similar result, we utilized thoracic epidural anesthesia for a coronary artery bypass via a left anterior thoracotomy, in an awake, spontaneously breathing patient. To the best of our knowledge, this is the first reported case utilizing this approach. Herein we report the results and technique utilized.

Redo left anterior descending artery grafting via left anterior small thoracotomy: an alternative approach.

Reoperative left anterior descending artery (LAD) revascularization can be performed through a left anterior small thoracotomy (LAST approach) in patients requiring isolated LAD revascularization. If the left internal mammary artery has been previously used, however, the operation is generally performed either through a median sternotomy or through a full posterolateral thoracotomy for the necessity of connecting the vein graft to the ascending aorta or to the descending thoracic aorta, thus losing the advantages of a minimally invasive approach. In the case reported herein, we describe a technique in which reoperative revascularization of the LAD is accomplished through the LAST approach, using the stump of the left internal mammary artery as the inflow site of a saphenous vein coronary graft to the LAD.

On-pump and off-pump coronary artery bypass grafting in the elderly: predictors of adverse outcome.

OBJECTIVE: To establish the role that coronary artery bypass grafting (CABG) without cardiopulmonary bypass (CPB) may have in improving perioperative outcomes of patients 70 years of age and older. BACKGROUND: Coronary revascularization in elderly patients is associated with morbidity and mortality rates higher than those observed in younger patients. The impact of CABG without CPB on perioperative outcomes has not been clearly established. METHODS: This retrospective, nonrandomized study consisted of 1,872 CABG patients. Of these, 1389 underwent CABG with CPB (CPB group) and 483 patients underwent CABG without CPB (off-pump group). Preoperative variables and outcomes were compared between the two groups. Multivariate logistic regression analysis was used to identify independent predictors of mortality, stroke, and adverse outcome. RESULTS: Demographics, Canadian Cardiovascular Society staging, operative priority, and other preoperative variables were comparable between the two groups. The prevalence of previous myocardial infarction was higher in the CPB group (62.6% vs 56.7%; p < 0.005), whereas the prevalence of calcified aorta and preoperative renal failure were higher in the off-pump group (5.4% vs 9.5%; p = 0.04 and 1.7% vs 3.3%; p = 0.04, respectively). Although the graft/patient ratio was higher in the CPB group (3.4 vs 1.9), these patients displayed more extensive coronary artery involvement. At univariate analysis, patients in the off-pump group had a higher rate of freedom from complications (88.2% vs 81.3%; p < 0.005) and a lower incidence of stroke (2.1% vs 4.2%; p = 0.034) than patients in the CPB group. Although there was a trend for a higher actual mortality in the off-pump group (4.8% vs 3.7%; p = ns), the risk adjusted mortality in this group was lower (1.9% vs 2.1%). Multivariate analysis showed that while the use of CPB correlated independently with an increased risk of overall complications, it was not associated with a higher probability of death or stroke. CONCLUSIONS: This investigation suggests that elderly patients undergoing CABG may benefit from off-pump revascularization, as the use of CPB correlated independently with an increased risk of overall complications. However, CPB did not emerge as an independent predictor of death or stroke at multivariate analysis.

Myocardial revascularization of the beating heart in high-risk patients.

OBJECTIVE: Myocardial revascularization without cardiopulmonary bypass (CPB) has been proposed as an alternative technique in patients at high risk for conventional coronary artery bypass grafting (CABG). The purpose of this article is to evaluate the potential benefit of such an approach. METHODS: We retrospectively evaluated the perioperative results of off-pump CABG (OPCAB) performed from January 1995 to December 1999. Patients were divided into three groups on the basis of their preoperative risk factors: age greater than 80 years, reoperative CABG, and left ventricular ejection fraction percentage (LVEF%) less than 40%. The three subgroups were compared with patients operated on-CPB (ONCAB) during the same period of time. A total of 172 octogenarians had ONCAB versus 97 OPCAB, 307 reoperations were ONCAB versus 274 OPCAB, and 514 patients with LVEF% less than 40% were operated ONCAB versus 220 OPCAB. RESULTS: Preoperative comorbidities were homogeneously distributed in the OPCAB and ONCAB groups. More extensive coronary artery disease was found in the ONCAB groups. A trend for a lower number of perioperative complications was reported in the OPCAB groups. Freedom from overall complications was significantly higher (p < 0.005) in the OPCAB group. Actual mortality rates in the OPCAB and ONCAB groups were comparable (p = NS). CONCLUSIONS: CABG can be performed safely without CPB in patients with a high preoperative risk profile. Freedom from perioperative complications is markedly higher when the OPCAB approach is utilized.

"Single suture" for exposure of the heart in left ventricular assist device placement.

Using the "single suture" technique described for exposure of the heart during off-pump coronary surgery, all surfaces of the heart may be exposed with little hemodynamic compromise. Using this technique, the apex of the heart is easily elevated for left ventricular assist device (LVAD) insertion in patients with either ischemic or dilated cardiomyopathy. This technique may provide the groundwork for routine placement of LVADs without the use of cardiopulmonary bypass.

Acute right ventricular failure during aortic root replacement: intraoperative diagnosis and treatment.

The scope of this article is to report on a patient who underwent a Bentall procedure for type A aortic dissection. Right ventricular (RV) failure developed immediately after completion of the operation. The etiology was determined by using transit time flow measurement (TTFM), an ultrasound-based technique which demonstrated the absence of blood flow to the right coronary artery. This allowed for early and effective treatment, which was followed by a successful outcome.

Technical tips and pitfalls in OPCAB surgery: the buffalo experience.

The Center for Minimally Invasive and Robotic Heart Surgery has performed more than 1,500 off-pump coronary artery bypass (OPCAB) procedures since 1995. The operation has changed significantly based on experience and development of new tools. These improvements have made the operations safer and applicable to more patients. No patients are presently scheduled for on-pump bypass surgery in our center. The purpose of this paper is to describe some of the problems and pitfalls we have experienced and how to avoid them.