Vascular malformation of the brain stem

Seventy-five cases treated by microsurgery from 1985 to 1995 are reported. There were 51 males and 24 females, aged from 6 to 70 years, mean 37 years. The duration of symptoms varied from 4 days to 24 years (average 1.9 years). The lesions were mainly in the pons in 50 cases, in the mid-brain in 18 cases, and in the medulla in 7 cases. The pathological results were 51 cavernous angiomas, 9 telangiectasis, 4 AVMs, 6 unidentified and 5 multiple lesions. Their clinical manifestations and neuro-imaging were analyzed. MRI is considered as the most useful means for indicating surgical treatment while CT plays a certain role in emergency examination. Follow-up: No operative mortality. In 45 cases (60%), the pre-operative symptoms have improved. 25 cases had new symptoms after operation, 16 of them gradually recovered. Two patient with lesion in the pons and medulla had stress ulcers after surgery. Vascular malformation occurs in any place of the brain stem, and most of them are cavernoma. Generally, their bleeding is intraparenchymatous. We have never seen one whose bleeding ruptured into the subarachnoid space. Indications for operation are larger hematomas, progressively deteriorating clinical manifestations or enlarging tendency of the lesion on neuro-imaging. Different surgical approaches are adopted according to the concrete location of the lesions in the brain stem. The overlying thinnest area, usually discolored, is selected as the entry into the brain stem. Radical excision of the lesion and minimal damage to normal tissue is stressed.