Prashant Kumar, B (2009) On-Pump Coronary Artery Bypass Graft Surgery Versus Off-Pump Coronary Artery Bypass Surgery: A Comparative Surgery. Masters thesis, Madras Medical College, Chennai.
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Abstract
INTRODUCTION : Cardiovascular disease had emerged as a major health burden worldwide. Heart disease contributed to a major chunk of deaths of which majority is from developing countries. A rise in the prevalence of cardiovascular diseases in the early twentieth century and a subsequent decline in the latter half has been well documented in the industrialized countries. However the scenario is reversed in developing countries especially India with a steady escalation in the prevalence of cardiovascular diseases. It has been consistently observed that Indians have premature CAD and that their risk for CAD is two to four times higher than European population and ten times higher than that reported 40 years ago. The emerging trend of CAD in India shows that there is an increase of the disease in the young population. And occurring in younger patients, the disease pattern is severe. Within the Indian subcontinent also, there has been a rapid rise in CAD prevalence. CAD has a multifactorial etiology with many of the risk factors being influenced by lifestyle, prominent factors being dietary and smoking, diabetes mellitus, hypertension, obesity, COPD. One of the most debated and polarizing issues in cardiac surgery has been whether coronary artery bypass grafting (CABG) without the use of cardiopulmonary bypass (CPB) or cardioplegia (off-pump CABG, or OPCAB) is superior to that performed with the heart-lung machine and the heart being chemically arrested (standard CABG). Beating heart coronary artery bypass grafting is a technique developed to reduce usage of cardiopulmonary bypass. Till recently, CPB was considered to be the most important factor for creating a perfect vascular anastomosis in a quiet, motionless and bloodless field. Because of the many deleterious effects of CPB, recognized to be particularly important in the emerging scenario of an increasing number of elderly and high risk patients being taken up for CABG, off-pump bypass has gained importance. Many of the technical difficulties of the off-pump technique have been overcome by the development of devices such as stabilizers, snares, shunts, suction cones, etc. AIMS & OBJECTIVES: 1. To study the epidemiology of Coronary artery disease in the local population. 2. To evaluate the outcome after treatment for coronary artery disease. 3. To compare the outcome measures in the on-pump Versus the off-pump coronary artery bypass surgeries. 4. To compare our results with previous available studies. 5. To analyse the various complications of coronary artery bypass surgery. 6. To analyse and compare the advantages and disadvantages of on-pump versus off-pump bypass surgeries. MATERIALS AND METHODS : This study is a retrospective, nonrandomized observational study, based on coronary artery disease patients admitted in Government General Hospital, Chennai between January 2008 and December 2008, who underwent surgical intervention for coronary artery disease. Consecutive patients with diagnosis of coronary artery disease admitted in the cardiology and Cardiothoracic surgery departments , Government General Hospital, Chennai, were followed up and those patients who were taken up for surgical treatment were included in the study list. Medical records of these patients were analyzed for necessary data. Of all there were 134 patients who underwent surgical treatment during January 2008 to December 2008 period. Treatment was based on prior review of coronary angiograms of the respective patients. Patients who were operated on an emergency basis and patients who had previous cardiac surgery were excluded from this study. Patients were taken up for surgical management after obtaining informed consent; either on-pump or off-pump coronary artery bypass surgery. Decision was based on the opinions of the operating surgeons after reviewing the coronary angiograms of the patients. Triple, double and single vessel diseases were included in the study list. INTERPRETATION OF RESULTS : The incidence of coronary artery disease is observed to be more in males than the females in the local population. Triple vessel disease is more common in the distribution of coronary artery disease in the study population compared to two vessel and single vessel disease. The peak incidence of coronary artery disease was more in the fifth decade of life followed by the 51 to 60 age group when compared to the other age groups. This distribution is in stark contrast to the western population where coronary disease is more common after 60 years age indicating the shift of the disease to the younger age groups in the local population in India. The morbidity of the disease is increased by the various range of co-morbid diseases that co-exist with coronary disease. Diabetes, hyperlipidemia and hypertension are the most common co-morbid diseases seen in the study population. The other lesser common ones are COPD and renal dysfunction. Statistical analysis of the on-pump patients shows that the morbidity is more in patients who are converted from off-pump to onpump, indication of the cause of the conversion being hemodynamic instability. The most commonly used grafts were the left internal mammary artery graft and saphenous vein grafts. The conduction of the bypass surgery was easier in the on-pump group due to the better convenience to manipulate the heart without compromising the hemodynamic status of the heart. In the postoperative period, the mean ventilation time and intensive care time was marginally lesser in the off-pump patients. The overall hospital stay period shows very little difference between the two groups. Among the postoperative complications, bleeding was the most common, followed by renal and CNS complications. The other lesser complications were arrhythmias , and sternal wound infection and mediastinitis. It is noteworthy to mention here that arrhythmias were primary complications in a lesser number of patients than noted and more secondary as a result of the other complications of the patients. The calculated mortality was found to be more in the on-pump group compared to the off-pump group. But hidden within this fact is the probability that this increased rate was a result of bias on part of the operating surgeons to plan for on-pump surgery in the more complicated patients. But despite this bias, there is a noticeable difference in the mortality in the on-pump patients compared to the off-pump patients. CONCLUSION : The result of this analysis indicates that off-pump surgery is associated with less operative mortality and morbidity than on-pump surgery and that the use of cardiopulmonary bypass is an independent risk factor for mortality. Certain results are worthy of note. The first is that the use of cardiopulmonary bypass is an independent risk factor for mortality. Second, there appears to be a particular benefit of avoiding CPB in those subgroups generally considered high risk for CABG surgery, including the elderly, women, and patients undergoing reoperative operations. Third, as well as a mortality benefit, the performance of beating-heart surgery is associated with a significant decrease in perioperative morbidity including the need for blood transfusions, return to the operating room for bleeding, respiratory complications, and new-onset renal failure. A further potential benefit of beating-heart surgery was hoped to be improved neurological outcomes. This data despite its methodological shortcomings, support a benefit for OPCAB, which is consistent with numerous previous studies. In addition, OPCAB benefit persists despite elevated risk among those patients preferentially operated on off-pump. Ability to achieve superior outcomes in high-risk patients in terms of mortality and across a number of morbidity variables clearly speaks to the potential clinical benefit of this operation. Although not randomized, this study adds to the increasing body of patients and among sample sizes sufficient to form a generalized conclusion. The present study suggests that OPCABG reduces length of hospital stay, operative morbidity, and operative mortality as compared with on-pump coronary artery bypass surgery.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | On-Pump Coronary Artery Bypass Graft Surgery ; Off-Pump Coronary Artery Bypass Surgery ; Comparative Surgery. |
| Subjects: | MEDICAL > Cardio Vascular and Thoracic Surgery |
| Depositing User: | Kambaraman B |
| Date Deposited: | 10 Nov 2017 17:50 |
| Last Modified: | 11 Nov 2017 02:27 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/3883 |
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