Surgical management of medullary hemangioblastoma. Report of 47 cases.

BACKGROUND: Hemangioblastomas of the medulla are rare and seldom reported. Surgical resection of medullary hemangioblastomas is associated with high morbidity and mortality rates. We present a unique institutional experience over a 12-year period.
METHODS: Between 1987 to 1998, 47 hemangioblastomas were surgically resected and analyzed retrospectively. The follow-up ranged from 6 to 136 months with an average of 35 months.
RESULTS: Thirty-nine single hemangioblastomas were distributed in 3 anatomical areas: pontomedullary, medullary, and cervico-medullary. They were either focal intramedullary or dorsal exophytic. There were cyst formations in 97.4% of the single hemangioblastomas. The major feeding arteries and the tumor blush could be clearly visualized on angiogram, sometimes even on MRA. All medullary hemangioblastomas were radically removed. Postoperatively, 61.5% patients had clinical improvement, two patients' symptoms remained unchanged and 11 patients deteriorated; of the latter, 8 patients improved later with proper therapy, and 2 patients died.
CONCLUSION: Preoperative diagnosis of medullary hemangioblastoma is possible with MRI. With improved microsurgical technique and better understanding of the vascular pattern of the tumor, total surgical resection can be performed with <5% mortality. The surgical strategy is en bloc excision, as piecemeal resection can lead to uncontrollable hemorrhage. Removal of large solid hemangioblastomas may result in severe postoperative edema and/or hemorrhage in the medulla affecting the respiratory and vagal centers. Preoperative embolization through the posterior inferior cerebellar artery (PICA) can be helpful in this situation.