Cerebral cast angiography as an aid to medicolegal autopsies in cases of death after adult cardiac surgery

Abstract

Due to an increase in age of the patient population in cardiac surgery, cerebral complications are increasing in frequency, also as a cause of death. In order to reveal cerebral pathology associated with a fatal outcome after cardiac surgery, we re-evaluated the cast angiographs and medico-legal autopsy documents of 144 adult cardiac surgery subjects over a 7-year period. Special attention was paid to the ability of post-mortem cast angiography to aid in diagnosing cerebral pathology. The autopsy detected new ischemic cerebral lesions in 29 (20%) cases, of which 22 (15.3%) were recent infarcts, and 7 were cases of anoxic brain damage. Of the recent cerebral infarcts, 12 were associated with cerebral artery thrombosis, 4 showed multiple lesions, and the remaining 6 were small single infarcts. In addition, one subject had an intracerebral hemorrhage and 72 (50%) cerebral edema. By cast angiography, the leakage of contrast medium in the case of intracerebral hemorrhage and stenoses of intracranial and cervical arteries could be well demonstrated and also revealed 17 (77%) of the 22 recent cerebral infarcts. It was found to be suitable for detecting recent brain infarcts associated with main cerebral artery thrombosis, with a sensitivity of 92% (11 out of 12 cases), but was less sensitive in showing small recent infarcts with a sensitivity of 60% (6 out of 10 cases) and inferior for the older ones where none of the 6 cases were detected. Filling defects caused by cerebral edema were difficult to differentiate from technical errors and were encountered in 7 (4.8%) cases. A significant predictor for the 29 recent ischemic brain lesions was perioperative hypotension. The immediate cause of death was most often of cardiac (83%) and cerebral (14%) origin. In 14 cases, cerebral damage was considered to be an additional cause of death. The use of cerebral post-mortem cast angiography should be recommended, especially for its excellent ability to visualize intravascular pathology such as arterial stenoses and thromboses, with a 92% sensitivity in showing new main cerebral artery thromboses, before likely distortion of the vascular anatomy by dissection.