A simple post mortem room angiography method for the investigation of traumatic basal subarachnoid hemorrhage

Identifying the site of vascular bleeding in fatal cases of traumatic basal subarachnoid hemorrhage (TBSAH) is important, but can be very difficult to achieve when there is extensive blood clot in the posterior cranial fossa. Post mortem angiography in these circumstances has been reported previously but with mixed results, and is rarely used in current practice within the United Kingdom. We have developed a simple and effective post mortem angiography method, using fluoroscopy and clear modern contrast medium, suitable for use in the autopsy room. Contrast medium was injected through an angiographic catheter positioned (with water filled balloon) in the extracranial vertebral artery (ECVA) just behind the clavicle, whilst the base of the skull and upper cervical spine area was visualized by fluoroscopy following digital subtraction of the bony images. The procedure was developed over a series of 8 TBSAH cases and using unfixed cadaveric specimens. A clear leak point was identified in 3 cases and the likely site indicated in a further fatality (all with tears subsequently confirmed by histology). In 4 cases, the bleeding point was not identified by angiography. In 7 deaths, the anatomy of the upper cervical loops and intracranial course of the vertebral arteries were well delineated by angiography and several small loop segments were documented. In 1 case, with severe degenerative vascular disease, extracranial vessel wall trauma and luminal thrombosis, angiography was unsuccessful above the level of the first cervical (C1) vertebra. Injecting contrast through the internal carotid artery, just above the bifurcation, was also shown to visualize the anterior cerebral circulation well. This method is likely to identify the main site of vascular tearing in about 50% of cases of TBSAH and to delineate the important anatomy of the vessels, prior to dissection of the upper neck and posterior fossa, thus minimizing handling artefacts and guiding the histological sampling of the vessels.