Transoral transclival removal of anteriorly placed cavernous malformations of the brainstem

BACKGROUND: The natural history of brain stem cavernous malformations is unfavorable because of their high hemorrhage rate and resulting neurological deterioration among patients. However, direct surgery of intrinsic and anteriorly situated cavernomas is hazardous and leads to a bad postoperative outcome because of trauma to lateral and dorsally situated eloquent areas of the brain stem. METHODS: We review the cases of two patients with symptomatic cavernous malformations of the anterior brain stem and describe the usefulness of a transoral-transclival approach. A 23-year-old man developed progressive hemihypaesthesia and paraesthesia, hemiparesis with gait ataxia, dysarthria, dysphonia, and dysphagia. A 38-year-old woman suffered from an acute onset of vertigo with nausea and vomiting, diplopia, and paraesthesia of the left hand and foot. In both patients, computed tomography demonstrated the presence of brain stem hemorrhage, because of cavernous malformation. Magnetic resonance imaging showed a close proximity of the lesions to the pia mater only on the ventral surface of the brain stem. RESULTS: In both patients, the cavernomas could be safely approached and completely resected via a transoral transclival route. Three months after surgery, neurological examination revealed marked neurological improvement. The 23-year-old patient showed slight gait ataxia, no hemiparesis, no cranial nerve palsies; the 38-year-old woman demonstrated no neurological symptoms except for minimal motor dysfunction of the left hand. In both cases, under perioperative prophylactic antibiotics, no meningitis was observed. The patients could subsequently return to their previous employment. CONCLUSION: The transoral transclival approach for ventrally situated brain stem cavernomas allows a largely atraumatic resection of the lesion.