Autopsy findings in patients on postcardiotomy extracorporeal membrane oxygenation

Aims: To assess the clinical sensitivity of causes of death, concomitant diseases and postoperative complications in ECMO patients.

Methods: Within 5 years 1.079 (6.2%) died after cardiac surgery. 154 pts. had postcardiotomy ECMO circulatory support. Autopsy was performed in 78 (50.6%) consecutive pts.. Clinical and post-mortem data were prospectively recorded and compared concerning causes of death and complications including thromboembolisms and EuroSCORE relevant diseases.

Results: Mean age was 62.1 y, EF 43.4%. 71.8% were non-elective operations including ACS in 25.6% and cardiogenic shock in 29.5%. Survival was 13.0±21.8d. Clinical causes of death were cardiac in 62.8%, multi-organ failure/sepsis in 10.2%, cerebral in 5.1%, respiratory in 10.2%, fatal pulmonary embolism in 2.5%, technical in 3.8%, and others in 4.8%. Unexpected causes of death were found by autopsy in 21 patients (26.9%) including myocardial infarction (n=9), fatal pulmonary embolism (2), pneumonia (2) and fatal cerebrovascular event (4). Premortem unknown concomitant diseases were found in 62 patients (79.5%) and led to EuroSCORE alterations in 23.1%. Preoperative additive (logistic) EuroSCORE changes from 11.2 (31.1%) to 11.5 (33.7%) after autopsy evaluation (p<0.001). Clinically unrecognized complications were found in 59 patients (75.6%), including acute cerebral ischemia (8), gastrointestinal bleeding (5), pneumonia (9) and thromboembolic events.

Thromboembolic events	Clinical findings	Autopsy findings
Overall venous thrombosis	6 (7.7%)	32 (41.0)
Overall arterial embolism	3 (4.8%	15 (23.8%)
Left heart thrombus formation	1 (1.3%	8 (10.2%)

Conclusion: ECMO patients reveal major discrepencies at autopsy. Thromboembolisms are highly underestimated clinically.