State of the vein grafts, native coronary arteries, and myocardium and principal cause of death in patients dying after aortocoronary bypass grafting

Previously Unreported Complication of Coronary Artery Bypass Grafting: Suture Rupture Resulting in Patient's Death

Traditionally, the manner of death in most hospital autopsy cases is natural, in which death is due to the natural course of disease or reasonably anticipated outcomes of medical interventions. Some cases fall into a potential gray zone between natural and accident, including rare or unanticipated outcomes of medical interventions. We present a case of a patient postcoronary artery bypass graft. Autopsy revealed the proximal anastomosis of the aorta-to-first-diagonal-coronary-artery-to-second-obtuse-marginal-artery graft was detached from the aorta. A broken suture was present at the disconnected anastomosis, with intact knots but was broken along its length. In-hospital mortality rates of CABG range from 1% to 3%, with several autopsy studies identifying surgical complications as the cause of death in one-third of perioperative deaths. No publications were found that described suture rupture as directly relating to the cause of death. This case report describes a previously unreported complication of coronary artery bypass grafting.

Significant value of autopsy for quality management in cardiac surgery

OBJECTIVE

With recent advances in diagnostic imaging, the value of autopsy has been called into question. The aim of our study was to assess the current impact of autopsy for early postoperative quality management in cardiac surgery.

METHODS

Between 2000 and 2003, a total of 14,313 patients underwent cardiac surgery at our center. Of these, 898 patients (6.3%) died, and autopsy was performed in 468 cases (52.1%). Data from clinical and postmortem examination were prospectively analyzed regarding causes of death, postoperative complications, concomitant diseases, and surgery-associated pathologic findings.

RESULTS

Mean age was 68.7 years. Mean survival was 13.9 postoperative days. On autopsy, causes of death were cardiac in 49.8% of cases (n = 233), respiratory in 8.3% (n = 39), cerebral in 6.4% (n = 30), abdominal in 4.7% (n = 22), multiorgan failure or sepsis in 14.9% (n = 70), pulmonary embolism in 6.6% (n = 31), procedure associated in 8.3% (n = 39), and others in 0.9% (n = 4). Discrepancies between clinical and postmortem determinations of cause of death were found in 108 cases (23.1%). These were acute myocardial infarction (n = 38), low cardiac output (n = 9), respiratory (n = 8), cerebral (n = 5), abdominal (n = 7), multiorgan failure or sepsis (n = 12), pulmonary embolism (n = 18), and procedure associated (11). Clinically unrecognized postoperative complications were found in 364 cases (77.8%). Unknown concomitant diseases were found in 464 cases (99.1%), with potential therapeutic relevance in 90 cases (19.2%). In 85 cases (18.2%), autopsy examination revealed 96 premortem unrecognized surgery-associated pathologic findings.

CONCLUSION

A high overall discrepancy rate between premortem and autopsy diagnoses was recognized. Autopsy revealed clinically relevant information in a significant number of cases. Therefore autopsy remains essential for quality assessment in perioperative treatment.

Mechanisms of death in the early postoperative period following coronary artery bypass grafting for acquired heart disease. A clinicopathological study of 32 cases

OBJECTIVES

A retrospective cardiopathological and clinical study was conducted in order to determine causes of perioperative death following coronary artery bypass grafting (CABG).

EXPERIMENTAL DESIGN

Between January 1992 and June 1995, a total of 5749 CABG procedures were performed at the Heart Center Duisburg (Germany). Following the procedures, 218 patients died in hospital (mortality rate 3.8%). Fifty-eight were autopsied at the Institute of Pathology, Bethesda Hospital, Duisburg, and 32 autopsied cases were amenable to our study. Basis for selection was accessibility of clinical and morphological data and a postoperative death within 30 days.

METHODS

In each case, morphological analysis of the heart and an evaluation of surgical and clinical data were performed in order to draw a conclusion on the mechanism of death.

RESULTS

Using criteria defined by us, the following causes of death were determined: (1) surgical complications (43%); (2) severe coronary artery disease with incomplete revascularization (41%); (3) congestive heart failure (13%); (4) non-cardiac complications (3%).

CONCLUSION

Criteria defined in this study may be useful in evaluations of causes of death after open heart surgery and may help to compare results in future series. Determination of the cause of death is important for the cardiac surgeon to reconsider indications and quality of surgical procedure.

Post-mortem examination after cardiac surgery

Following a recent enquiry into surgery at a paediatric cardiac centre in England, there will be substantial changes in the way that the success and failure of surgical procedures will be monitored and investigated. Post-mortem examinations on patients dying after cardiac surgery are likely to be performed and reported in more detail. This review describes the protocol that we have developed and summarizes recent clinical and pathological studies that have increased our understanding of postoperative pathophysiology. Close attention should be paid to the history, particularly the operation note. Cardiac failure is the commonest cause of death. We believe this is a clinicopathological diagnosis and provide definitions of preoperative and perioperative cardiac failure. Haemorrhage, stroke, pulmonary emboli and infection are other important causes of death. Methods of dissection are suggested for bypass grafts and valve replacements. Two recent studies show that the post-mortem examination provides answers to most clinical questions and reveals an unexpected cause of death in 10-15% of patients. There are limitations however: an incomplete or indeterminate cause of death is found in 14-25% of patients, most commonly sudden clinically unexplained death or clinically unexplained cardiac failure soon after surgery.

Prospective study of the value of necropsy examination in early death after cardiac surgery

OBJECTIVE

To assess the value of necropsy examination in patients dying soon after cardiac surgery, particularly the proportion of clinical questions answered by the necropsy, the frequency of major unexpected findings, and the limitations of the procedure.

DESIGN

A three year prospective study of necropsy examinations in adult patients dying before discharge or within 30 days of cardiac surgery performed under cardiopulmonary bypass in one hospital.

SETTING

Tertiary referral centre.

RESULTS

123 of 2781 patients (4.4%) died in the early postoperative period, and necropsy examination was performed in 108 of these (88%). The mortality after emergency procedures (18%) was much higher than after routine operations (2.6%). The main causes of death were cardiac failure (52%), haemorrhage (14%), cerebral disease (6%), and pulmonary emboli (5%). The necropsy changed the stated cause of death in 16 patients (15%), and answered clinical questions in 24 of 38 patients. In 15 patients necropsy examination did not provide a full explanation of death. Most of these patients died of cardiac failure soon after surgery or were sudden unexpected deaths.

CONCLUSIONS

Necropsy examination in patients dying early after cardiac surgery is valuable as it answers the majority of clinical questions, and shows unexpected findings in a significant proportion of cases.

Surgical technique and operative mortality in coronary artery bypass. A postmortem analysis with castangiography

Post-mortem analysis with castangiography was performed on 54 patients who died within 30 days of coronary artery bypass surgery. Myocardial failure was the cause of 85% of the deaths. There were 215 coronary anastomoses (4.0 +/- 1.1/patient), 24% of which were non-functioning. Most of the occlusions were due to various technical failures. The most striking features were 1) high occlusion rate (25%) in sequential vein grafts and 2) disastrous complications of coronary endarterectomies. Compared with preoperative angiographic data, only 15 (28%) of the 54 patients were found to have 'complete' revascularization, with patent grafts and all stenosed coronary arteries bypassed. The need for recognition and avoidance of technical complications is stressed: Failures of surgical technique constitute a major risk factor in coronary artery surgery.