Results of combined coronary endarterectomy and coronary bypass for diffuse coronary artery disease

Early and Late Outcome After Off-Pump Coronary Artery Bypass Graft Surgery With Coronary Endarterectomy: A Single-Center 10-Year Experience

BACKGROUND

We aimed to review the early and late results of off-pump coronary artery bypass graft surgery (OPCABG) with coronary endarterectomy in patients undergoing surgical revascularization at our institution.

METHODS

Between 1995 and 2004, of 680 OPCABG patients in a single surgeon's practice (W.R.D.), 70 patients (10.29%) who underwent concomitant coronary endarterectomy were studied. The mean age was 63.6 +/- 9.29 years. Thirty-three patients (55%) were Canadian Cardiovascular Society class III or IV, and 24 patients (40%) were New York Heart Association class III or IV. Eighteen patients (35%) had impaired left ventricular function. The mean EuroSCORE of these patients was 5.9 +/- 1.8.

RESULTS

Fifty-seven patients (81%) underwent right coronary artery endarterectomy, and 12 patients (17%) underwent left anterior descending artery endarterectomy (8 left interior mammary arteries used as conduits). Four patients (5.7%) had two vessels endarterectomized. The mean number of grafts were 2.0 +/- 0.4. The 30-day mortality rate was 2.85% (n = 2). Three patients (4.3%) suffered from postoperative myocardial infarction, and 3 patients (4.3%) required postoperative intra-aortic balloon pump counterpulsation. Mean intensive therapy unit stay was 17.6 +/- 8.1 hours. Patients were extubated after a mean of 10.38 +/- 4.9 hours. The mean length of hospital stay was 6.1 +/- 2.0 days. Fourteen patients (20%) had postoperative atrial fibrillation, and only 1 patient (1.42%) had a transient stroke with complete recovery. There were no conversions to cardiopulmonary bypass. A mean of 0.86 +/- 0.17 units of blood were transfused postoperatively. There was one reopening for bleeding, and 1 patient had renal failure requiring hemofiltration. The median follow-up was 4.91 years, 90% of patients were angina free, and the actuarial survival at 10 years was 78.04% +/- 7.6%.

CONCLUSIONS

Off-pump coronary artery bypass graft survery with coronary endarterectomy is feasible and achieves surgical revascularization in patients with diffuse coronary artery disease.

Outcome of coronary endarterectomy: a case-control study

BACKGROUND

Despite early reports showing a high incidence of postoperative morbidity and mortality, coronary endarterectomy continues to be used as an adjunct to coronary artery bypass grafting, particularly in diffusely diseased coronary arteries. The changing nature of patients and improvements in modern cardiac surgery call for a reevaluation of the role of coronary endarterectomy.

METHODS

Data from the 56 patients, who underwent coronary endarterectomy in our institution between January 1993 and August 1996, were reviewed retrospectively and compared with a control group of 56 patients matched for age, sex, LV function, and angina class. In the endarterectomy group, there were 47 men and nine women, with a mean age of 59.6 years. The mean follow-up time was 21 months. Indications for operation were angina in 45 (80.3%), angina with signs or symptoms of cardiac failure in 3 (5.4%), and prognosis in 8 (14.3%) asymptomatic patients.

RESULTS

Fifty (89%) patients had one, four (7.2%) had two, and 2 (3.6%) patients had three coronary arteries endarterectomized. Of these 64 endarterectomies, 33 (51.5%) involved the right coronary artery, 20 (31.3%) the left anterior descending artery, and 11 (17.2%) branches of the circumflex artery. There were three (5.4%) nonfatal myocardial infarctions in the endarterectomy group, but none in the control group (p>0.05). Two patients (3.6%) in the endarterectomy group, but none in the control group, died within the first 30 days (p>0.05). Actuarial survival and incidence of recurrent angina were similar in the two groups.

CONCLUSIONS

In current cardiac surgical practice, coronary endarterectomy displays satisfactory rates of postoperative morbidity and medium term results in selected groups of patients.

Long-term results of reconstructions of the left anterior descending coronary artery in diffuse atherosclerotic lesions

One hundred twenty patients who had diffuse atherosclerotic lesions necessitating reconstruction of the left anterior descending artery with or without open endarterectomy and coronary artery bypass grafting were investigated retrospectively and compared with 130 patients who underwent conventional bypass grafting in the same time frame.

METHODS

Sixty-one endarterectomies were performed with long arteriotomies (group I) and 59 patch reconstructions were placed over stenosing plaques without an endarterectomy (group II). Patients having only conventional coronary bypass constituted group III.

RESULTS

Hospital mortalities were 6.5%, 5.1%, and 1.5% in group I, group II, and group III, respectively (p = not significant). Five patients in group I (8.1%), six in group II (10.1%), and two in group III (1.5%) had perioperative myocardial infarction (group II vs group III, p = 0.016). Angiographic restudy of grafts to the left anterior descending system revealed a patency rate of 81.5% in group I, 79.1% in group II, and 94.4% in group III patients after mean periods of 6.3, 5.7, and 6.1 years, respectively (p = not significant). Actuarial survivals at 7 years were 94% +/- 5.0%, 74.8% +/- 16%, and 90.9% +/- 7.4% in groups I, II, and III, respectively (group I vs group II, p = 0.007; group II vs group III, p = 0.008). Freedom from recurrent angina at 7 years was 42.7% +/- 15.6% in group I, 33.5% +/- 19% in group II, and 71.9% +/- 14.2% in group III (group I vs group III, p = 0.03; group II vs group III, p = 0.0001). Thirty-four percent of patients in group I, 24% in group II, and 60.4% in group III were working actively in the late postoperative period (p = 0.0001).

CONCLUSION

Extended revascularizations of the left anterior descending coronary artery increase surgical risk, although not to a statistically significant degree, and should be performed only of necessity. However, once needed, revascularization is a lifesaving procedure with acceptable early and long-term results.

Adjunctive coronary endarterectomy: improved safety in modern cardiac surgery

BACKGROUND

Advances in cardiac surgery have led to an improved safety record for coronary endarterectomy.

METHODS

We retrospectively reviewed the cases of 64 patients who underwent adjunctive coronary endarterectomy between August 1988 and February 1992. There were 44 men, and the mean age was 65 years. Forty-one patients (64%) had sustained a previous infarction. Overall, endarterectomy was performed on 76 vessels, and the right coronary system was involved in 46 (61%).

RESULTS

The postoperative infarction rate was 5%. Incomplete occlusion ( < 90% stenosis) of the endarterectomized vessel significantly increased the risk of infarction (p < 0.05). There were two early deaths (3%). The mean follow-up was 46 months. Clinically, 91% of the survivors were angina free, and 80% had no symptoms of heart failure at the time of follow-up. Left ventricular function had improved in 36% of those restudied (5/14). A total of 17 recatheterizations were done at a mean interval of 19 months after operation. The endarterectomy graft patency rate was 80% (16/20) compared with 78% (28/36) for conventional grafts ( p = not significant). The actuarial survival rates were 89% and 71% at 1 year and 5 years, respectively. A history of previous infarction was significantly associated with higher long-term mortality (p < 0.02).

CONCLUSIONS

Overall, these results demonstrate that in modern cardiac surgery, coronary endarterectomy is safer than previously thought and can be used effectively to achieve complete revascularization in selected patients.

Angioscopic evaluation of intravascular morphology after coronary endarterectomy

Coronary endarterectomy in diffuse coronary disease is attended by an increased incidence of perioperative myocardial infarction and vein graft occlusion, which have been partially attributed to the presence of occlusive or thrombogenic intraluminal flaps in the main vessel or its smaller branches. To define the nature and incidence of these features we studied 15 endarterectomized right coronary arteries in 15 patients (12 men, 3 women; age, 55 +/- 7 years [mean +/- standard deviation]) undergoing a coronary operation for multivessel disease. After endarterectomy and distal graft anastomosis, angioscopy was performed using a 1.8-mm Olympus angioscope during graft perfusion with crystalloid solution. The endarterectomy cores were 66 +/- 30 mm in length with 11 major bifurcations and two trifurcations providing 30 major endpoints. At 22 of 30 major endpoints the distal end of the core was smooth and tapered. There were 17 minor side-branch endpoints. Angioscopy revealed the presence of wispish intraluminal fronds and medial bruising in all (100%) arteries. Twenty-nine of the 30 intraluminal endpoints could be visualized. Major intraluminal flaps were seen at the eight nontapered endpoints and six of the 21 smooth tapered endpoints that were visualized. Fifteen minor side branches could be identified angioscopically: a flap was seen at only one side-branch origin. The average examination time was 3.2 +/- 1.1 minutes (7.7% +/- 2.7% of cross-clamp time), and examination required 200 to 250 mL of perfusate. This technique enables immediate and accurate postinterventional assessment of intravascular morphology with minimal prolongation of ischemic time and has shown that small side branches are not compromised by endarterectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Direct CO2 laser "revascularization" of the myocardium

Evidence of regional myocardial perfusion and contractile function after direct CO2 laser myocardial revascularization (DLR) is lacking. We examined myocardial segment shortening, adenine nucleotide concentrations, and regional blood flow after DLR of the left anterior descending coronary artery (LAD) distribution before and after its proximal ligation in seven anesthetized conditioned dogs. Sonomicrometry assessed myocardial fiber shortening and radioactive microspheres were used to estimate baseline regional blood flows. Cardiopulmonary bypass was followed by cardioplegia arrest. Laser channels (1 mm diameter) were made every 3 to 5 mm in the LAD region with an 80 watt Laser-sonics CO2 unit. Bypass was terminated, the LAD occluded, and parameters reassessed. Core samples of myocardium from the lased LAD and control circumflex area were taken to assess adenine nucleotides. After occlusion, LAD distribution blood flow and myocardial shortening were reduced to pre-lasting ischemic controls. Adenine nucleotides were reduced in the LAD region relative to the control CMX area. DLR cannot be relied upon to acutely revascularize the ischemic myocardium.

Controversial aspects of coronary endarterectomy

Between 1980 and 1987, 635 patients underwent coronary bypass grafting combined with coronary endarterectomy. A total of 728 vessels were endarterectomized and grafted. There were 15 early deaths (2.3%). The mortality rate was higher (7.8%) for multiple-vessel endarterectomy (p less than 0.05). The ratio of MB fraction of creatine kinase to total creatine kinase was greater than or equal to 0.10 in 48% of the cases. The first consecutive 132 survivors were followed for an average of 16 months (range, 4 months to 5 years). No late deaths occurred. Fifty-nine unselected patients underwent postoperative recatheterization at a mean interval of 18 months. An improvement in heart wall contractility could be detected in 13 patients (16.5%) and deterioration in 14 patients (17.7%). A more detailed analysis of wall contractility showed a higher rate of improvement in the posterior wall than in the anterior wall (p greater than 0.05). Furthermore, the better the contractility before operation, the greater the rate of deterioration after operation (p less than 0.05). Despite an average of 55% of all endarterectomized vessels being occluded or severely restenosed, 90% of the patients were clinically improved. A multiparametric analysis revealed that the revascularization of myocardial areas that required endarterectomy had no significant influence with respect to clinical improvement. Endarterectomy should be limited, whenever possible, to myocardial areas with already impaired contractility. Endarterectomy of multiple branches should be treated with caution because the risk of deterioration is potentiated, with a significantly higher perioperative mortality rate.

Coronary endarterectomy--angiographic and clinical results

Of 75 patients who underwent coronary endarterectomy, 16% had left main stem stenosis, 4% one-vessel, 27% two-vessel and 53% three-vessel disease. On average 2.9 grafts per patient were inserted, in conjunction with 82 manual endarterectomies (38 right coronary, 35 left anterior descending, 9 circumflex branches). In 68/75 cases (91%) the endarterectomy was not preplanned and in 39 cases (52%) greater than or equal to 3 cm of the atherosclerotic core was removed. All four early deaths (5%) followed endarterectomy of LAD. Acute perioperative myocardial infarction was confirmed in 19% and probable in further 8%. At angiography 1-139 (median 25) months postoperatively, all three internal mammary artery grafts and 19/34 saphenous vein grafts (56%) to endarterectomized vessels were patent, though in 4 of the 19, the coronary artery was occluded distal to the anastomosis. In addition 17/18 conventional internal mammary artery (94%) and 48/59 conventional saphenous vein grafts (81%) were patent. The vein graft patency rate was not significantly influenced by postoperative anticoagulant therapy, but was significantly increased among patients with relief of angina: 44% reported freedom from angina and 92% at least some relief after a median of 3 years. The 5-year and 10-year survival rates were 85% and 68%. Despite the increased risk, endarterectomy can be recommended for severely diseased major coronary arteries.

Coronary endarterectomy. An adjunct to coronary artery bypass grafting

There is a wide variation in the reported results of endarterectomy in conjunction with coronary artery bypass grafting. Operative mortality ranges from 0 to 10 per cent, perioperative infarction ranges from 5 to 30 per cent, and patency rates range from 38 to 100 per cent, with 74 to 95 per cent being asymptomatic or improved. This wide discrepancy in clinical outcome occurs for a number of reasons. First, there is nonhomogeneity of patient populations resulting from a lack of standardized patient selection criteria. Second, the operative experience of most published reports spans a decade throughout which major advances in cardiac surgery have occurred. Finally, endarterectomy is a technically challenging procedure with its own learning curve. Differences in technique and expertise almost certainly contribute to the variability of results. Patients with diffuse coronary artery disease pose a challenge to the cardiac surgeon. Endarterectomy entails the risks of increased morbidity and mortality and therefore should be done only if conventional bypass grafting is precluded. However, the risks of these complications must always be weighed against the possible benefits. At the present time carefully selected patients can benefit from this procedure. Unfortunately, until such time as controlled randomized studies are carried out on a prospective basis, statistical support for this procedure will not be available. Given that such a study is questionable from an ethical point of view, clinical decisions for this select group of patients must be done on a case-by-case basis. The best that can currently be done is to carefully follow these patients and scrutinize existing data to ensure optimal clinical management.

Usefulness of thromboendarterectomy in association with coronary artery bypass grafting

Thromboendarterectomy is sometimes performed in association with coronary artery bypass graft surgery (CABG). Right coronary arteries and severely narrowed coronary arteries mainly undergo thromboendarterectomy, but perioperative acute myocardial infarctions (AMI) are possible complications. One hundred seventy-six consecutive patients with rest and stress thallium-201 scintigraphy and angiography were studied before and after surgery. To compare patients with and without thromboendarterectomy, 48 patients who had undergone thromboendarterectomy and whose characteristics matched closely those of patients who had not were selected. Twenty patients had previous AMI before CABG in each group. Analysis accounted for the severity of vessel lesion (complete or incomplete) and for the patency of the graft and of the native coronary artery. In these 96 patients, graft patency was lower than in the overall group and similar among patients with and without thromboendarterectomy among the 56 patients without previous AMI. In patients with previous AMI and thromboendarterectomy, however, reperfusion was achieved more often through the native vessel than through the graft. New AMI or residual ischemia occurred in 32% of the areas undergoing thromboendarterectomy and in only 5% of the standard grafts (p less than 0.001). Best results were obtained in patients with incomplete occlusion after AMI. Patients without previous AMI had worse results. Thus, thromboendarterectomy can yield 64 to 75% good results in selected subgroups when CABG is otherwise impossible, but should be avoided in mildly or moderately stenotic arteries perfusing noninfarcted myocardium.

Bypass grafting to the right coronary artery with and without endarterectomy: patency at one year

Between January 1979 and December 1981, 142 patients undergoing surgery to the right coronary artery agreed to have repeat coronary arteriography one year later. Thirty patients underwent combined endarterectomy and bypass grafting to the right coronary artery. The patency of these grafts was compared with that of grafts in 69 patients undergoing direct grafting to the right coronary artery and in 43 with grafting to the posterior descending coronary artery. There were two hospital deaths and one late death. No patients developed new inferior Q waves on the electrocardiogram. Repeat coronary arteriography at one year showed that 21 (72%) of the 29 grafts were patent after combined endarterectomy and bypass grafting to the right coronary artery. Sixty three (94%) grafts to the right coronary artery and 40 (93%) grafts to the posterior descending coronary artery were patent at one year. Direct grafts to the right coronary artery or its posterior descending branch had a significantly higher patency rate at one year than grafts to the endarterectomised right coronary artery. Graft patency after the combined procedure correlated with the extent of atherosclerosis in the posterior descending coronary artery. It was not influenced by treatment with platelet antagonists. Endarterectomy of the right coronary artery was most successful when it allowed a single graft to perfuse both the large posterior descending and left ventricular branches.

Intraoperative retrograde balloon-catheter dilatation to augment myocardial revascularization

When bypass graft surgery is planned, it is appreciated that sequential coronary artery stenoses often entrap the origins of arterial branches that have a significant, but subgraftable, diameter. These branches are routinely not perfused by saphenous vein grafts implanted beyond the second lesion. Data are presented on improving perfusion of such branches in 26 patients by the technique of retrograde intraoperative balloon-catheter dilatation. During coronary artery surgery, specially designed angioplasty catheters, 2 to 3 mm in diameter, were introduced through the coronary arteriotomy and passed retrogradely across the distal lesion. Balloon inflation was performed two to four times at 4 to 7 atm. Lesion size was assessed before and after angioplasty with the use of graduated coronary probes. Probe-determined lesion diameter increased from 1.1 +/- 0.4 to 2.0 +/- 0.4 mm (percent increase, 109 +/- 8). In selected patients, intraoperative balloon-catheter dilatation is a promising technique adjunctive to coronary surgery. Clinical significance and long-term effectiveness of this procedure require further evaluation.

Early and late results of combined endarterectomy and coronary bypass grafting for diffuse coronary disease

Between October 1969 and December 1979, a total of 440 patients who had diffuse coronary artery disease were treated with combined endarterectomy and coronary bypass grafting. This constitutes 42 percent of all patients operated on at the same institution during this period. Six hundred eight endarterectomies were performed, 329 on the right coronary artery, 227 on the left anterior descending coronary artery and 52 on the left circumflex coronary artery. The early mortality rate was 4.3 percent and the late mortality rate 9 percent during a mean follow-up period of 47 months. The perioperative infarction rate was 15 percent. Ninety-five percent of survivors were asymptomatic or in improved condition. Only 11 patients were lost to follow-up study. Three hundred fourteen patients (71 percent) were reinvestigated with coronary and graft arteriography 1 month to 8 years postoperatively. The early patency rate of grafts to the endarterectomized vessels was 85 percent and the late patency rate (1 year or more) was 77 percent. The runoff was good in 79 percent, fair in 14 percent and poor in 7 percent of grafts. Endarterectomy is a valuable additional procedure in the management of patients with diffuse coronary artery disease.

Manual coronary endarterectomy with saphenous bypass: experience with 263 patients

From January, 1972, until August, 1980, 271 manual coronary endarterectomies with bypass were performed in 263 patients. All patients underwent additional cardiac procedures simultaneously. The group contained 254 distal right and 17 left endarterectomies (including 8 double endarterectomies). Clinical follow-up was 100%, operative mortality was 2.3% (6 out of 263), and the rate of perioperative infarction was 4.9% (13 out of 263). Cineangiography was performed on 72 patients between 1 and 60 months after operation (mean, 15.4 months). Patency was 85% (61 out of 72). Endarterectomy in a dominant right coronary artery could be planned electively. Left coronary endarterectomy was performed only when diffuse disease prevented standard bypass. Coronary endarterectomy may be used to extend operability with excellent clinical results, low perioperative mortality, and high late patency. Careful attention to technical aspects of core removal and myocardial protection are necessary for consistent results.

Patency and flow response in endarterectomized coronary arteries

Ninety patients, operated on from May, 1978, through June, 1979, underwent coronary endarterectomy and early recatheterization. Patency of grafts to endarterectomized arteries was 103 of 118 (87.3%) and patency of conventional vein grafts in the same patients was 217 of 233 (93.1%). Myocardial blood flow using xenon 133 washout, at rest and with isoproterenol-induced stress, was measured in 7 normal coronary arteries, 28 conventional saphenous vein grafts, and 33 saphenous vein grafts to endarterectomized coronary arteries. The increase in myocardial blood flow, from rest to isoproterenol-induced stress, was comparable for the three groups. The endarterectomized group was divided further by separating out the 10 patients with heavy scarring or residual disease. The remaining patients had a flow response identical to those with conventional saphenous vein grafts. The rate of perioperative infarction in patients receiving endarterectomy was 3 of 113 (2.6%), as measured by appearance of new persistent Q waves on the serial postoperative electrocardiogram. Positive pyrophosphate scans were noted in 12 of 105 (12.4%) patients. It is concluded that, in the early stages at least, grafts to endarterectomized coronary arteries stay open and perfuse the myocardium as well as conventional saphenous vein grafts unless the myocardium is heavily scarred or unless residual disease remains.

Selective retrograde coronary venous perfusion

The theoretical concept of delivering oxygenated blood to an ischemic myocardium by way of the coronary venous system antedated by many decades the present widespread utilization of coronary artery bypass grafting. Diffuse arterial atherosclerosis has limited the effectiveness of coronary artery bypass grafting in about 15% of patients seen with significant angina pectoris. Consequently, there has been renewed interest in selectively reversing the flow in certain coronary veins through coronary venous bypass grafts. This collective review details the physiology and anatomy of the coronary venous system. It then discusses the early attempts to globally retroperfuse the entire coronary venous system through the coronary sinus. Finally, the current experimental and clinical attempts to selectively retroperfuse just one region of the coronary venous system are presented and reviewed.