Reoperation for coronary graft failure: clinical and angiographic results in 43 patients.

Reoperation because of early or late coronary graft failure was performed in 43 patients who were part of a group of 1,985 patients operated on for coronary artery disease and followed for up to 7 years. Considerable variation in the results was noted depending on whether the patients were symptomatic or not before reoperation. Of the symptomatic patients, 85% were asymptomatic late (30 months) after reoperation whereas of those patients reoperated on despite the apparent lack of symptoms, 71.5% remained free from angina later on. Moreover, patency rate was high (94.4% or 17/18 grafts) in the first group and much lower (38.4% or 5/13 grafts) in those reoperated on solely on the basis of an early angiogram showing malfunctioning grafts. Patency rate was higher when the graft was totally replaced (92.3% or 12/13 restudied) rather than repaired simply through interposition of a segment of vein (37.5% or 3/8). It is apparent that results of reoperation in symptomatic patients are identical to those of an initial revascularization. On the other hand, patients who are asymptomatic despite early evidence of malfunctioning grafts should be reoperated on only when optimal angiographic conditions are present, that is, a coronary artery that is a good size, severely narrowed, and supplying a large myocardial area.     

Prophylactic coronary artery grafting in patients with few or no symptoms.

Fifty-five patients who underwent prophylactic coronary artery grafting were followed for 4 to 8 years. Sixteen patients had no angina, and 39 were in New York Heart Association Functional Class I. Twenty-one patients had single-vessel disease, 13 had double-vessel disease, and 27, triple-vessel disease. A total of 101 grafts were inserted. There were no operative deaths. Two patients suffered a perioperative myocardial infarction (MI), and 3 were reoperated on for persistent bleeding. Early after operation, 9 of the 45 grafts were occluded. At 1 year, 2 patients had occlusion of all grafts, and 1 had similar findings at 5 years. There were 4 late deaths, 3 related to coronary artery disease. Seven patients sustained a late MI. Thirty-one of the 51 survivors (60.8%) seen late (mean, 69.3 months) after operation were free from angina; 14 were in Class I and 6, Class II. It is apparent from this retrospective study that patients such as these stand to benefit little from prophylactic revascularization. Longevity may be increased, however, in patients who are asymptomatic after MI.     

Successful Course After Supraarterial Myotomy for Myocardial Bridging and Milking Effect of the Left Anterior Descending Artery

We report 3 patients having a grade III milking effect of the proximal left anterior descending artery (LAD) and suffering from angina. Preoperative myocardial ischemia was demonstrated by stress ECG in all 3 and by pacing and lactates studies in 2. Surgical decompression of the systolically constricted artery has resulted in disappearance of angina, milking, and ischemia.Severe milking of the LAD is a rare entity, probably congenital in origin, capable of producing myocardial ischemia and possibly causing sudden death. More studies regarding its etiology and pathophysiology are necessary. Biopsy of the myocardium surrounding the artery could be useful.     

Thromboembolic Complications with the Cloth-Covered Starr-Edwards Aortic Prosthesis in Patients Not Receiving Anticoagulants

A comparison of the incidence of thromboembolic (TE) episodes was made in three groups of patients who underwent aortic valve replacement with the cloth-covered Starr-Edwards prostheses. Group 1 consisted of patients who received anticoagulants for either the entire period of follow-up or for a period of variable duration, after which these agents were no longer administered. When anticoagulants were stopped, 22 patients were categorized as Group 3 for study. Group 2 comprised patients who never received anticoagulants.Of the 147 patients followed in Group 1, 14 suffered one episode of TE. Six patients experienced major emboli; 3 of them died. Twenty of the 82 patients followed in Group 2 (no anticoagulants) suffered TE complications. There were 10 episodes of major emboli. Five of the 22 patients in Group 3 suffered an episode (all major) of TE.It is concluded from this study that anticoagulants should be given permanently to all patients with cloth-covered Starr-Edwards prostheses. Indeed, there is no period after operation when the incidence of TE is so low that anticoagulation may be safely discontinued.     

Sequential Anastomoses in Coronary Artery Grafting: Technical Aspects and Early and Late Angiographic Results

The present study concerns itself with the early and late results obtained with aortocoronary vein grafts containing more than 1 coronary anastomosis per graft. The surgical technique is described in detail and some of the hazards are outlined. It is apparent that the use of side-to-side anastomoses (SSAs) leads to a marked increase in blood flow in the proximal portion of the graft (average flow, 131 ml/min) and also increases the patency rate of the proximal anastomosis. Thus, 3 of 51 SSAs were obstructed on the early angiogram, and only 1 of the 28 SSAs restudied at one year had become occluded. Although the cumulative—early and late—patency rate (55/66, or 83.3%) of the distal end-to-side anastomoses (ESAs) was not significantly better than that usually seen with conventional vein grafts, it is believed that improvement in the technique and greater awareness of some of its pitfalls will further decrease the occlusion rate of distal ESAs. Most occlusions of the ESA appeared related to angulation, which tended to occur in the segment of graft between the proximal and the distal anastomoses. Appropriate modifications in the technique are described that should help to eliminate this difficulty.The use of SSAs also allows for grafting of small coronary arteries which, with the conventional single anastomosis technique, are not usually bypassed in view of the high expected failure rate. Thus, of the 9 SSAs performed to 1 mm arteries and studied on two occasions, 8 remained open early after operation and 7 were still patent a year later.     

Sympathetic denervation in association with coronary artery grafting in patients with Prinzmetals' angina.

Myocardial revascularization in patients with Prinzmetal's angina has yielded variable results. Two patients are presented who underwent partial cardiac sympathectomy in combination with coronary artery grafting for typical variant angina associated with severe organic obstructive coronary artery disease. Late results 12 and 18 months postoperatively have been excellent in both instances as shown by clinical and angiographic evaluation. Although the exact mechanism responsible for Prinzmetal's angina is not known, it is believed that spasm through increased activity of vasomotor tone or of the autonomic nervous system plays a major role. Since this variant form of angina encompasses a whole spectrum at angiography, ranging from normal arteries to severely narrowed ones, including those with spasm, it is suggested that surgical treatment be planned accordingly. Thus, in patients who have organic stenoses with and without spasm, operative treatment may consist of removal of the preaortic or pretracheal plexus in association with conventional coronary artery grafting. In patients who have intractable episodes of ventricular arrhythmia or angina and who angiogram is normal or shows isolated spasm, coronary artery grafting should be abandoned, in view of the poor results reported in the literature in these circumstances, and cervicothoracic sympathectomy should be considered.     

Clinical and Hemodynamic Results with the Carpentier-Edwards Porcine Bioprosthesis

Carpentier-Edwards bioprostheses were implanted in 605 patients, 509 of whom had a single valve replacement, and 96 of whom had a multiple valve replacement. There were 54 early deaths (8.9%) and 26 late deaths (4.3%). The five-year actuarial survival was 87% for aortic valve replacement, 83% for mitral valve replacement, and 81% for multiple valve replacement. Of the 525 survivors, all but 3 were followed for a total of 964 patient-years; 354 patients (68%) remained asymptomatic, and 95 patients (18%) were improved. The incidences of thromboembolism, endocarditis, and reoperation due to primary tissue failure of the bioprosthesis were 2.0, 1.3, and 0.1% per patient-year, respectively. The actuarial probability of being free of all valve-related complications was 93% after five years. Satisfactory hemodynamic performance of the bioprosthesis was demonstrated by postoperative studies done in 70 patients. Thus, the Carpentier-Edwards porcine valve provides good clinical improvement, with a low incidence of valve-related complications and tissue failure at five years postoperatively.     

MB creatine kinase and the evaluation of myocardial injury following aortocoronary bypass operation

Myocardial injury was studied in 104 patients undergoing coronary artery grafting without cold chemical cardioplegia using the quantity of the isoenzyme MB of the creatine kinase liberated as an indicator. This method of evaluation, which is said to permit comparison of different techniques of myocardial protection, allowed us to consider the relative importance of several factors believed to have an influence on intraoperative myocardial injury. Indices of significance were duration of symptoms before operation, presence of chronic arterial hypertension, and the type of antiangina treatment employed. Other operative factors included severity of the arterial lesions, number of anastomoses performed, and duration of extracorporeal circulation and of aortic cross-clamping.     

A simple device for achieving pulsatile flow during cardiopulmonary bypass.

We describe a simple modification of the roller pump capable of producing a pulsatile flow during extracorporeal circulation. The technique is simple and can be readily duplicated in any center that uses roller pumps for cardiopulmonary bypass. Studies are in progress to evaluate the advantages of this type of perfusion.     

Cold Blood–Diltiazem Cardioplegia

The calcium channel blocker, diltiazem, has been studied in the same model used for evaluation of cold blood–potassium cardioplegia. Six dogs (Group 1) had one hour of myocardial ischemia with topical ice (myocardial temperature, 7° ± 2°C) after coronary perfusion with 200 ml of cold blood (5° ± 1°C) containing diltiazem, 400 μg per kilogram of body weight. Seven dogs (Group 2) had two hours of ischemia after perfusion with 200 ml of cold blood containing 200 μg/kg and reperfusion every 30 minutes with 100 ml of cold blood and diltiazem, 100 μg/kg. Baseline studies were repeated after rewarming and 40 minutes of reperfusion. No inotropic agents or calcium were used.Heart rate, peak systolic pressure, velocity of the contractile element, peak + rate of rise of left ventricular pressure (dP/dt), peak ? dP/dt, dP/dt over common peak isovolumic pressure, left ventricular compliance and stiffness, and heart water were unchanged in Group 1. In Group 2, heart rate slowed (p < 0.025) and compliance decreased (p < 0.02). In both groups, coronary vascular resistance declined (p < 0.001) and recovery of adenosine triphosphate (p < 0.001), adenosine diphosphate (p < 0.025), and the adenosine pool (p < 0.001) was impaired. Ultrastructure was well preserved, but myofibrillar lesions were noted in Group 2.Diltiazem cardioplegia was associated with good functional recovery, but there was impairment of high-energy phosphate metabolism.     

Perceval Sutureless Aortic Valve Implantation: Midterm Outcomes

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Coronary Artery Grafting with the Saphenous Vein or Internal Mammary Artery: Comparison of Late Results in Two Consecutive Series of Patients

In two series of consecutive patients who underwent coronary artery grafting with the saphenous vein or the internal mammary artery (IMA), angiographic studies were conducted two weeks and one year after operation. The early patency rate was 91.8% in 184 vein grafts and 97.4% in 38 IMA grafts. Late patency was 93.1% in 143 vein grafts and 90.9% in 33 IMA grafts. Thus, the cumulative patency rate at one year was 84.9% for vein grafts and 88.3% for IMA grafts.The incidence of severe narrowing at the site of anastomosis was 2.2% in vein grafts and 7.9% in IMA grafts; the rate of occlusion of the distal limb of the recipient coronary artery was, respectively, 4.3 and 7.9%. Diffuse reduction in the caliber of grafts at one year was less frequent with IMA grafts (12.7 versus 6.6%). On the other hand, blood flow was significantly higher in vein grafts: 67.4 versus 45.2 ml per minute (p < 0.001). Blood flow in IMA grafts whose caliber was larger than that of the recipient coronary artery was significantly higher than flow in IMA grafts with a caliber equal or inferior to that of the coronary artery: 63.1 versus 32.7 ml per minute (p < 0.001).Although cumulative patency rates at one year were comparable in both series, because only one-third of the IMAs were larger than their recipient coronary arteries, flow was somewhat restricted in the other two-thirds. This suggests that the IMA does not constitute the better bypass conduit and, unless it is of large caliber, preferably should be used in the grafting of small coronary arteries or those with limited runoff.