Techniques of exposure and stabilization in off-pump coronary artery bypass graft

A coronary active perfusion system for off-pump coronary artery bypass: advantage over passive perfusion regarding the physiology of the coronary artery

To avoid myocardial ischemia during off-pump coronary artery bypass, we developed a coronary active perfusion system (CAPS) that perfuses arterial blood to the coronary artery at the diastolic phase of the cardiac cycle by a syringe pump system. We report herein the details and compare CAPS with a passive shunt circuit from the femoral artery (FA shunt), regarding the physiology of the coronary artery. Six pigs were used for this study. After CAPS or FA shunt perfusion was established, coronary flow and coronary pressure were measured. The coronary flows in the native coronary artery, FA shunt perfusion, and CAPS perfusion with syringe pump stroke volume settings ranging from 0.1 to 0.4 ml were 27.2+/-3.0, 4.1+/-1.5, 12.7+/-1.2, 24.8+/-1.9, 33.3+/-1.6, and 42.2+/-1.9 ml/min, respectively. Mean coronary pressures under FA shunt perfusion and CAPS perfusion with stroke settings from 0.1 to 0.4 ml were 23.7+/-4.6, 48.8+/-5.0, 61.3+/-7.5, 70.8+/-5.4, and 82.3+/-5.2 mm Hg, respectively. CAPS had an advantage over the FA shunt regarding coronary flow with safe coronary pressure. Using CAPS, an off-pump coronary artery bypass can be performed safely without myocardial ischemia.

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.

Reoperative grafting of the LAD system using the LAST approach: technical details

In patients in whom the left internal mammary artery (LIMA) has been previously utilized, reoperative grafting of the left anterior descending (LAD) or diagonal coronary arteries can be performed through a left anterior small thoracotomy (LAST) approach, utilizing the subclavian artery as inflow source. In such cases, however, the left upper lobe of the lung and the lingula may exert unwanted traction on the newly constructed coronary graft. Herein, we describe a detail of technique that eliminates this inconvenience.

Survey of resident training in beating heart operations

BACKGROUND

"Off-pump" coronary artery operations are done with increasing frequency in the treatment of coronary artery disease. As a result, residents in thoracic surgery have been confronted with the necessity of gaining experience in this innovative approach to coronary surgery. The aim of this study was to assess the importance of training in minimally invasive coronary revascularization as it was perceived by thoracic surgery residents.

METHODS

A postal, multiple-choice survey questionnaire was sent to all cardiothoracic surgery residents (n = 327) of accredited training programs in the United States. Responses were tabulated and analyzed.

RESULTS

The overall response rate was 68% (222 of 327 residents). The attending staff was very interested (37%), or had some interest (63%), in beating heart coronary revascularization. Ninety-eight percent of the programs had at least one surgeon performing off-pump procedures. Although 88% of the responding residents showed some interest in off-pump coronary operations, only 22% of them had performed more than 20 off-pump cases, and even less (12%) had performed more than 20 cases of off-pump complete revascularization, or off-pump circumflex revascularization (4%). Sixteen percent of them had no clinical experience with these techniques. Regarding career intentions, 88% of the residents indicated that off-pump coronary operations were expected to be part of the practice, and 58% of them were interested in pursuing additional training in less invasive heart procedures.

CONCLUSIONS

The results of this survey suggest that training in off-pump coronary revascularization is variable across training programs, and that the majority of residents may not reach proficiency in coronary procedures on the beating heart during their residency. This may adversely affect their future expectations, as 88% of them would like to practice off-pump coronary surgery once the training is completed.