| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
ORIGINAL ARTICLE |
Department of Cardiology
1 Department of Cardiac Surgery
2 Department of Research and CME, Punjab Institute of Cardiology, Lahore, Pakistan
Abdul Rehman Abid, FCPS (CARD) Tel: +92 3336105574 Fax: +92 429200028 Email: drarehman{at}gmail.com, Room 1–4 A, Doctor’s Hostel, Punjab Institute of Cardiology, Lahore, Pakistan.
ABSTRACT
To compare hospital mortality and postoperative complications in patients with severe coronary artery disease undergoing coronary artery bypass grafting with or without coronary endarterectomy, 100 consecutive patients were divided into 2 groups of 50 patients each. Group 1 had coronary endarterectomy, and group 2 had no coronary endarterectomy. There were 87 men and 13 women, with a mean age of 54.79 ±7.8 years; 48% had stable angina. The right coronary artery was endarterectomized in 22 patients, the left anterior descending artery in 21, and the left circumflex in 7. There were no significant differences in outcomes. There was 1 hospital death in each group. Perioperative myocardial infarction occurred in 2 patients in group 1 and 1 in group 2. Endarterectomy is a suitable option to achieve complete revascularization in patients with refractory angina and severe diffuse disease.
Key Words: Coronary Artery Bypass • Coronary Artery Disease • Endarterectomy • Hospital Mortality • Myocardial Infarction
INTRODUCTION
The incidence of coronary artery disease (CAD) is increasing. With advances in nonsurgical methods to achieve myocardial revascularization, the patients coming for surgical revascularization are of complex anatomy. The options for this group are to leave them as inoperable, to carry out incomplete revascularization, or to undertake complete revascularization with coronary endarterectomy (CE). Complete revascularization is the most important goal of coronary artery bypass grafting (CABG).1,2 The first CE was performed in 1957.3 Because of high morbidity and mortality, this procedure lost favor.4 There is increased surgical risk with CE, but it has good long-term effects in selected patients.5,6 Over the last decade, CE has gained interest as a means of providing symptomatic relief and improved survival in cases of diffuse disease.2,7 In patients undergoing CE with CABG, hospital mortality of 0%–15% has been reported.7–11 Myocardial infarction (MI) secondary to acute graft closure is a major complication after CE, with an incidence of 1.5%–19%.7–11 Prolonged cardio-pulmonary bypass (CPB), recent MI, redo surgery, and poor ventricular function are predictors of hospital mortality.10 Recent advances in percutaneous coronary interventions have resulted in more patients with diffuse disease being referred for CABG.10 Early graft closure and shorter long-term patency rates are of concern because the endarterectomized vessels tend to become thrombosed.10 This study was designed to compare hospital mortality, perioperative MI, arrhythmias, and postoperative complications in patients undergoing CABG with or without CE.
PATIENTS AND METHODS
This prospective randomized study was conducted between December 1, 2006 and November 30, 2007. We studied 100 patients undergoing CABG who were divided into 2 homogeneous groups: group 1 was 50 patients who had CE; group 2 was 50 patients who had no CE. These patients were taken from our off-pump vs. on-pump CABG randomized trial, so allocation to on-pump or off-pump surgery was by chance and not planned for individual cases. Patients with advanced CAD not controlled by aggressive medical management, and those with diffuse CAD requiring surgical treatment were included. Patients with left ventricular ejection fractions 
30%, nonviable myocardium, redo CABG, or CABG with valve surgery were excluded. Informed consent was obtained prior to inclusion in the study. A standardized form for data collection included history, general physical and systemic examinations, and preoperative angiographic findings. Hospital mortality was defined as death occurring before discharge from the hospital. Perioperative MI was defined as persistent electrocardiographic changes (new Q waves, loss of R-wave progression, new intraventricular conduction defects), elevated creatinine kinase-MB or cardiac troponin, or new echocardiographic evidence of a wall motion abnormality occurring within 48 h postoperatively.9,10 Other hospital complications including atrial fibrillation, renal failure, cerebrovascular accident, low-output syndrome (use of inotropic support for more than 24 h, or an intraaortic balloon pump to wean from CPB or maintain a systolic blood pressure of 100 mm Hg), and wound infection were compared between groups.10 CE was carried out in severely diseased vessels where conventional CABG was impossible. Most endarterectomies were planned before surgery, but a final decision was taken at the time of surgery.
Saphenous vein grafts and left internal mammary artery (LIMA) were used, with LIMA always anastomosed to the left anterior descending coronary artery (LAD). On-pump operations were performed using CPB with intermittent crossclamping and fibrillation, moderate hypothermia, and pulmonary artery venting. CE was undertaken in major coronary arteries and branches with an external diameter 
1.5 mm. CE was not attempted if there was nonviable myocardium determined by a perfusion scan. A limited incision was made at the proposed site of anastomosis, and atherosclerotic plaque was dissected proximally and distally using an endarterectomy spatula, with extraction by a traction technique.10 In the LAD, proximal endarterectomy was limited so as not to compromise septal perforators. In other vessels, to avoid competitive flow between the native vessel and the vein graft, the atherosclerotic plaque was divided 2 mm proximal to the incision site. CE was easier in beating heart procedures because counter-traction was provided by the beating heart. To ensure complete removal of plaque, the core was inspected for a smooth distal tapering end. If this was not seen, a second incision was made after palpating the vessel, which was closed with a vein patch, using 7/0 Prolene suture. The LIMA was anastomosed distally end-to-side, using 7/0 Prolene. If the LIMA was not of adequate size or the arteriotomy was longer than 2 cm, a vein patch was used to close the defect, and the LAD was anastomosed to the vein patch; this was required in only 4 patients. In the remaining vessels, saphenous vein was anastomosed to the arteriotomy, using 7/0 Prolene. Following completion of all graft insertions, the patient was weaned from CPB in the usual manner, with reversal of heparin by protamine. In the off-pump patients, an Octopus 4 tissue stabilizer (Medtronic, Inc., Minneapolis, MN, USA) was used prior to endarterectomy and grafting under full heparinization. Postoperatively, the patients were transferred to the intensive care unit. All CE patients received aspirin 75 mg and clopidogrel 150 mg 2 h postoperatively, provided there was no excessive drainage (<100 mL h–1 for 2 h), followed by aspirin 75 mg and clopidogrel 75 mg daily. Injections of 5,000 IU unfractionated heparin (Leo Pharmaceutical Products) 8 hourly was started along with aspirin and clopidogrel. Both antiplatelets were given for 3 months; only aspirin 75 mg was continued for life. To optimize graft patency in endarter-ectomized vessels, 2 antiplatelet agents were considered better than one for the first 3 months.12 All patients were examined daily until discharge, and weekly for 30 days postoperatively; all complications were recorded. As our endpoint was hospital complications, postoperative angiography for evaluation of graft patency was not carried out.
Statistical analyses were performed using SPSS version 14.0 software for Windows (SPSS, Inc., Chicago, IL, USA). Categorical variables were analyzed using the chi-squared test, and continuous data were analyzed using Student’s t test. Variables were compared between groups by applying the chi-squared test. Associations with outcomes were considered statistically significant if p values were less than 0.05.
RESULTS
Similar risk factors were present in both groups (Table 1
). All patients had severe 3-vessel CAD. Operative variables are listed in Table 2. In group 1, 45 (90%) patients underwent single-vessel CE, 4 had 2-vessel CE, and 1 had 3-vessel CE. There were no significant differences in hospital mortality and most other postoperative variables between groups (Table 3). One patient in group 1 suffered a perioperative anterior wall MI followed by low-output syndrome that ultimately proved fatal, and a patient in group 2 with low-output syndrome died on the 3rd postoperative day. One patient in group 1 having LAD endarterectomy developed anterior wall MI (diagnosed by new segmental wall motion abnormalities in the anterior wall on transthoracic echocardiography), and another having CE of the right coronary artery had an inferior wall MI evident as new Q waves in leads II, III, and aVF. One patient in group 2 had inferior wall MI diagnosed by new Q waves in leads II, III, and aVF. A cerebrovascular accident occurred on the 3rd postoperative day in one patient in group 1, who recovered within 3 days, with no residual neurological deficit or permanent disability.
|
|
|
Our overall rates of hospital mortality (2%) and perioperative MI (3%) are comparable with those of other studies.7–17 Ogus and colleagues8 reported long-term results of LAD reconstruction with LIMA in 574 patients; postoperative mortality was 1.9% and the perioperative MI rate was 6.9%. After 3, 5, and 7 years of follow-up, overall survival was 93.8%, 89.6%, and 85.5%, respectively. Among survivors, the patency rate of LIMA-to-LAD anastomoses was 91.4%. Vohra and colleagues9 reported postoperative MI in 4.3% of 70 patients undergoing off-pump CE, with the highest incidence of MI on postoperative day 3 or 4; 30-day mortality was 2.85%. In our study, MI occurred during the first 24 h and we feel this is the time of maximum hypercoagulability due to the raw surface, hence the need for early dual antiplatelet therapy. The majority (65%) of patients in our study had on-pump CABG, although we feel that CE is easier to perform off-pump, as reported by Vohra and colleagues;9 however, the results were similar in off-pump and on-pump cases. Nurozler and colleagues13 reported a perioperative MI rate of 6.2% and overall mortality of 3.1% at 14 ± 3.3 months. In both these studies, off-pump CE was mostly to the right coronary artery only. Most of our patients (90%) had single-vessel CE, which could be a reason for lower mortality and morbidity compared to studies with more multivessel CE.
A limitation of our study was the small number of patients in each group. The results might have been more meaningful if we had more patients and similar numbers with single- and multivessel CE, as well as postoperative angiography to assess graft patency in endarterectomized and non-endarterectomized coronary arteries. Our study was limited to hospital outcome, and we were unable to assess the long-term patency of grafts or endarterectomized vessels. Chen and colleagues14 found no recurrence of angina in 44 patients followed up for 6–29 months; those undergoing coronary angiography at 3–27 months postoperatively had 100% graft patency in endarterectomized grafts. Takanashi and colleagues17 reported an early angiographic patency rate of 96.2% for LIMA-to-LAD grafts in patients undergoing off-pump coronary artery reconstruction with or without CE, for a diffusely diseased LAD. Fukui and colleagues11 performed CE in 67 patients; the patency rate of LIMA-to-LAD grafts was 98.6% on early angiographic examination. They recommended that diffusely diseased vessels having either continuous plaques with calcification, soft large plaques, or hard fibrous plaques should not be treated by either simple distal anastomosis or the plaque exclusion method; endarterectomy is the only revascularization method suitable for these complex vessels. We agree with this, and performed CE with a plaque extraction technique. Kumar and colleagues7 showed that CE does not increase mortality or morbidity, and it facilitates complete revascularization in diffuse CAD, and hence possibly offers survival benefits.
It was concluded that CE with CABG has a favorable hospital outcome in patients with diffuse CAD. Hospital mortality and perioperative MI had similar incidences in patients undergoing CABG with or without CE. For patients with refractory angina and severe diffuse disease, endarterectomy is a suitable option to achieve complete revascularization.
ACKNOWLEDGMENTS
The authors deeply acknowledge the Residents of Cardiac Surgery Department, Punjab Institute of Cardiology Lahore, and Miss Alliya Akhtar for their help in completion of this article.
REFERENCES
Asian Cardiovasc Thorac Ann 2009;
17:59-63
© 2009 by SAGE Publications
DOI: 10.1177/0218492309102609
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
