Direct myocardial revascularization without extracorporeal circulation. Experience in 700 patients

Coronary artery surgery with induced temporary asystole and intermittent ventricular pacing: an experimental study

Coronary artery bypass grafting performed without cardiopulmonary bypass presents a difficulty in performing coronary anastomoses on a beating heart. A non-cardiopulmonary bypass technique in sheep by which individual sutures can be placed on a still heart is described. Epicardial pacing wires were placed and a curved needle passed between the aorta and pulmonary artery into the muscular interventricular septum and directed caudally and to the right. The tip of the needle now lay in the vicinity of the outflow of the bundle of His. No cardiac chamber or vital structures were traversed. Injection of lignocaine here resulted in immediate ventricular asystole. Ventricular pacing restored cardiac output. After establishing local control of the vessel coronary anastomosis was performed stopping ventricular pacing for the few seconds required to place a single suture and reinstating it between the passage of sutures. Reversion to sinus rhythm occurred spontaneously.

Minimally invasive coronary artery bypass grafting

BACKGROUND

Standard options for the invasive management of proximal disease of the left anterior descending coronary artery include coronary artery bypass grafting with a left internal mammary artery and percutaneous transluminal coronary angioplasty.

METHODS

We describe a surgical technique for bypass of the left anterior descending coronary artery with a left internal mammary artery without median sternotomy and without cardiopulmonary bypass. Thoracoscopy is used to harvest the internal mammary artery, whereas the mammary-coronary artery anastomosis is performed under direct vision through a limited anterior thoracotomy.

RESULTS

We have performed this procedure successfully in 3 patients with minimal morbidity and shortened hospital stay. Average operative time was 3 hours and postoperative hospital stay averaged less than 48 hours.

CONCLUSION

Although experience is limited and follow-up is very short, with further experience, this less invasive surgical technique may become a viable option for the management of proximal left anterior descending disease.

Coronary grafting using a temporary intraluminal shunt instead of heart-lung bypass

The application of a temporary intraluminal shunt is presented as a technique to prevent ischemia when coronary grafting is performed without cardiopulmonary bypass. This simple maneuver expands the indications for coronary grafting without cardiopulmonary bypass.

Video assisted coronary bypass surgery

An alternative way to revascularize coronary vessels is described, using arterial conduits without extracorporeal circulation. The heart is exposed via a small thoracotomy over the fifth left intercostal space. A thoracoscope is introduced into the thorax, to assist in the harvesting of the left internal mammary artery (LIMA). In selected patients with two or three vessel disease, the same procedure can be achieved on the right side, harvesting the right internal mammary artery to revascularize the right coronary artery. The gastroepiploic artery can be easily reached and used to revascularize the posterior descending artery, through a mini-subxiphoid median laparotomy. This technique was used to revascularize 30 patients from April 1994 to June 1995. All received a LIMA graft to the left anterior descending artery, and two had a free radial artery graft from the LIMA, sequentially bypassing the diagonal and obtuse marginal branches. There was neither perioperative mortality nor morbidity myocardial infarction. Fifteen patients were restudied angiographically before discharge. Average hospital stay was 43 +/- 11 hours.

Coronary artery bypass without cardiopulmonary bypass: analysis of short-term and mid-term outcome in 220 patients

Two hundred twenty patients, preferentially those with high-risk conditions, underwent coronary artery bypass grafting without cardiopulmonary bypass. Early unfavorable outcome events included operative mortality (7 patients, 3.2%), nonfatal perioperative myocardial infarction (6 patients, 2.7%), cerebrovascular accident (1 patient, 0.4%), and sternal infection (3 patients, 1.4%). There were two deaths (13%) among 15 patients with calcified aorta and four (12%) in 33 patients who underwent emergency operation. Multivariate analysis revealed these two risk factors to be the only predictors of early mortality (odds ratios, 8.0 and 9.8, respectively). Preoperative risk factors such as left ventricular dysfunction (ejection fraction < or = 35%) (40 patients, 18%), congestive heart failure (46 patients, 21%), acute myocardial infarction (59 patients, 27%), cardiogenic shock (7 patients, 3%), age 70 years or older (59 patients, 27%), renal failure (19 patients, 9%), and cerebrovascular accident and carotid disease (11 patients, 5%) were not found to be major predictors of early mortality or unfavorable outcome. During 12 months of follow-up (range 1 to 21 months), there were four cardiac and three noncardiac deaths (1-year actuarial survival 93%) and 17 cases (7.7%) of early return of angina. Calcified aorta, nonuse of the internal mammary artery, reoperation, and diabetes mellitus were independent predictors of unfavorable events. We conclude that coronary artery bypass grafting without cardiopulmonary bypass can be done with relatively low operative mortality, although there seems to be an increased risk for early return of angina. This procedure should therefore be considered for patients with appropriate coronary anatomy, in whom cardiopulmonary bypass poses a high risk. This procedure is still hazardous with calcified aorta or emergency operation.

Unusual pitfall of use of retrograde cardioplegia

The use of retrograde cardioplegia can lead to several complications, mainly related to injuries during the cannulation of the coronary sinus. We herein present a case report of injury to the right coronary artery related to kinking due to the pursestring on the right atrium.

Clinical use of the Hemopump cardiac assist system for circulatory support

We have used the Hemopump in 15 patients in whom weaning from cardiopulmonary bypass was unsuccessful. The median time for the patients having the device on was 1.6 days postoperatively. They spent an average of 6 days in the intensive care unit and had a total hospital stay of about 17 days. Nine of 15 patients (60%) survived and were able to leave the hospital. There were some reversible decreases in kidney function in all patients, but none of them needed hemodialysis. Coronary artery bypass grafting supported by the Hemopump instead of cardiopulmonary bypass and with the use of a short-acting beta-blocker, esmolol, was carried out successfully in 12 patients. In this method the blood is oxygenated by the patient's lungs and the heart is perfused with its own warm blood. The Hemopump supports the circulation and if the patient needs circulatory support after the operation, a left ventricular assist device is already in place. There were no device-related complications apart from two initial cable fractures. The Hemopump fits well in the intensive care unit environment; it is silent, and the management of the console is easily learned. The Hemopump has shown to be an effective and safe tool for unloading the left ventricle while maintaining multiorgan perfusion. There are several potential applications for surgeons and cardiologists.

Coronary artery operation with support of the Hemopump cardiac assist system

Five patients with one- or two-vessel disease had one to three bypass grafts using the Hemopump cardiac assist system instead of cardiopulmonary bypass to decompress the heart and as circulatory support. In addition, the short-acting beta-blocker esmolol was given as a bolus and stepwise titrated to make the heart flaccid and facilitate operation. All patients had a 24F Hemopump placed into the left ventricle. The patients were given 7,500 U of heparin. Average time on Hemopump support was 56 minutes. All patients went through the procedure uneventfully. Thirty minutes after pump removal all patients were back to baseline hemodynamic values. None of the patients needed blood transfusion. No postoperative renal impairment was seen. This method has great potential and could avoid the drawbacks associated with cardiopulmonary bypass and cardioplegic arrest. Careful evaluation in randomized studies is the next step.

Coronary artery operation supported by the Hemopump: an experimental study on pig

Twelve pigs undergoing coronary artery bypass grafting had the Hemopump to decompress the heart and as circulatory support. The pigs also were given a short-acting beta-blocker, esmolol, to make the heart flaccid. Extracorporeal circulation was not used. During Hemopump support, a bolus dose of 0.5 to 5 mg/kg of esmolol was given before incremental titration steps from 100 to 600 micrograms.kg-1.min-1 over 15 to 20 minutes. The internal thoracic artery was sutured to the distal part of the left anterior descending artery. The Hemopump was withdrawn to the aorta after a weaning period of 20 to 30 minutes. Seven of 12 pigs went through the whole procedure and the Hemopump was weaned off without complications. Five animals died due to right ventricular failure in association with esmolol administration. There was a big interindividual difference in esmolol dose-response curves in the surviving animals. No significant differences in the hemodynamic variables were observed during the experiment. The Hemopump in combination with a short-acting beta-blocker could be an alternate way of performing coronary artery bypass grafting in selected patients.

Reoperative coronary artery bypass grafting without cardiopulmonary bypass

Between June 1979 and January 1992, 46 men and 13 women aged 35 to 81 years (mean, 58 years) underwent reoperative coronary artery bypass grafting without cardiopulmonary bypass. Isolated reoperative circumflex bypass was performed through a left thoracotomy, and reoperative bypass to the right coronary artery and left anterior descending coronary systems was through a median sternotomy. Complete revascularization was the goal in all patients. Saphenous vein grafts were placed to the right coronary artery (n = 21), circumflex artery (n = 11), and left anterior descending artery (n = 24), and 14 internal thoracic artery to left anterior descending artery bypass grafts were performed. The overall mortality rate was 3.4% (2 deaths). Postoperative morbidity included myocardial infarction in 1 patient and pleuropulmonary complications in 6. No patient was reexplored for hemorrhage, and 19 patients required no blood products. Twenty patients underwent repeat coronary angiography, and 18 of 20 grafts placed without cardiopulmonary bypass were patent. At a mean follow-up interval of 42.2 months 35 of 50 evaluable patients were in functional class I or II. In selected patients, reoperative coronary artery bypass grafting can be performed without cardiopulmonary bypass with a low perioperative morbidity and mortality rate, satisfactory graft patency rates, and good long-term symptomatic improvement.