Surgical treatment of pontomedullary cavernomas

Abstract

Direct treatment of brainstem cavernous haemangiomas (cavernomas) naturally represents a considerable surgical challenge due to the close proximity of vital structures. The results of such treatment have only rarely been described. We report our experience in the management of seven patients with cavernomas of the brainstem treated by microsurgical resection. All patients presented with neurological symptoms directly attributable to one or more episodes of brainstem haemorrhage. CT scan examination in all cases revealed either obvious haematoma or a focal region of high density within the pons or medulla; calcification in and around the lesion was detected in two patients. MRI scanning was performed in four of our cases and was strongly suggestive of the diagnosis of cavernoma with evidence of both recent and older haemorrhage as evidenced by haemosiderin deposits. Cerebral angiography failed to disclose abnormal vessels to the cavernoma in any instance, although interestingly a co-existent but separate cerebellar venous malformation was observed in two of our cases. Surgery was performed between 19 days and 3 months following the most recent haemorrhage. Microsurgical removal of both haematoma and underlying cavernoma was accomplished either via a median suboccipital or retromastoid craniectomy, with an appropriate incision being made into that part of the brainstem most directly overlaying the lesion. Significant improvement in neurological function has followed in all seven cases. Although the natural history of symptomatic cavernous haemangiomas is incompletely understood, the favourable results obtained in our patients suggest that total surgical removal is both practicable and relatively safe even in the case of those lesions situated within the branstem.

Key Words:

• Brainstem haematoma
• brainstem surgery
• cavernous haemangioma
• venous malformation