Surgical Removal of Pontomesencephalic Cavernous Hemangiomas

Abstract

Cavernous hemangiomas of the brain stem are usually discovered accidentally during evacuation of a hematoma, and successful surgical treatment of these lesions is seldom achieved. With the increasing use of magnetic resonance imaging, the presence of a cavernous hemangioma can be detected before surgery, allowing an elective surgical approach. We successfully removed pontomesencephalic cavernous hemangiomas from 2 patients and pontomedullary hemangiomas from 2 others. Elective surgery was performed with perioperative bimodal monitoring of somatosensory and auditory evoked potentials. Performing surgery soon after the hemorrhage minimizes the risk of additional postoperative neurological deficit, since surgical excision is facilitated when the hematoma is not completely organized. Pontine hemangiomas are approached via the 4th ventricle. Mesencephalic hemangiomas are removed by a midline supracerebellar approach when they are lateralized by using a subtemporal approach. The lesion can be removed through a small incision in the brain stem at the site of the lesion. The favorable results, which include marked improvement of preoperative neurological deficits and documentation of complete removal of the lesion by magnetic resonance imaging, support a more aggressive approach to the treatment of symptomatic cavernous hemangiomas of the brain stem. Further investigation of the natural history of these lesions is mandatory.

Improvement of Severe Retrocochlear Hearing Loss and Vestibular Disorders Caused by Ruptured Brainstem Cavernous Angioma

“…Due to the risk of recurrent bleeding, it is desirable to resect BCMs 15,18,19) , but conservative therapy is expected for venous angioma as long as it is asymptomatic because it is involved in the normal venous circulation 12,20,21) . Radiosurgery may be selected according to the risk of the surgery and the patient's condition.…”

Intraoperative rupture of brainstem cavernous malformation

“…Some authors have argued that early surgery for brainstem CMs after rupture is important to minimize the development of perilesional gliosis. 6 Nevertheless, Samii, et al, 18 failed to find a statistical significance in outcome in lesions that were surgically treated either within or after 3 months of rupture in a series of 36 brainstem CMs. Our preference has been to allow, when possible, sufficient time for the clot to liquefy and thereby assist in the dissection of the malformation from the surrounding brainstem.…”

Anterior pontine cavernoma: what should be done?

“…9 The treatment of choice is surgery, 4-6 weeks after bleeding, although the time is still controversial because the approach is easier in the period that the hematoma is not yet organized; in this case, the goal is the complete removal, preventing recurrence of bleeding and functional worsening. 1,14,15 However, before indicating the surgical procedure, the main differential diagnosis (pontine glioma and multiple sclerosis) must be excluded.…”