Traumatic dissecting pathology of posterior cerebral artery: a report of two cases-aneurysm and pial arteriovenous fistula.

We present two cases of 17-year-old man and 10-year-old boy presenting with subarachnoid haemorrhage and a history of road traffic accident. One patient had dissecting aneurysm of the posterior cerebral artery (PCA), and the other patient had partially thrombosed aneurysm on CT angiography. On digital subtraction angiography of the second patient, there was formation of PCA pontomesencephalic vein pial arteriovenous fistula (PAVF). Both the patients underwent endovascular treatment: stent-assisted coiling for aneurysm and coiling with parent vessel occlusion for PAVF. There were no procedural complications. Follow-up angiography showed no residual aneurysm or fistula. Trauma is one of the recognised causes of dissection, and intracranial dissections can present as stenotic lesions, aneurysms or fistulas, depending on the pathology. Traumatic dissecting PCA aneurysm has been reported in only two case reports previously, and post-traumatic PAVF in PCA has not been reported.