Resection of Pontine Cavernoma with Hemorrhage via Unilateral Uvulotonsillar Keyhole Approach.

The telovelar approach and its modifications are widely used to remove lesions of the fourth ventricle and brainstem. We offer a variant of a unilateral uvulotonsillar approach, which is performed using an open-door keyhole suboccipital craniotomy (Video 1). A 56-year-old woman presented with symptoms of 2 months' duration. Preoperative examination revealed paresis of the left sixth cranial nerve, left seventh nerve paralysis, right-sided hemihypoesthesia, right-sided severe hemiparesis owing to which the patient could not move independently, and dynamic ataxia in the left limbs. Magnetic resonance imaging showed a cavernoma with hemorrhage in the left side of the pons. The surgery was performed in the prone position. After a median skin and soft tissue incision about 6-7 cm long, an open-door keyhole craniotomy was performed. Dura over the left cerebellar hemisphere was opened in a semilunar fashion. The dissection of the uvulotonsillar fissure was performed from its cranial part, where the medial trunk of the cortical segment of the posterior inferior cerebellar artery was the reference point. Following the dissection, the tela choroidea was incised, and the left half of the rhomboid fossa was exposed. After the mapping, the floor of the fourth ventricle was incised in the suprafacial triangle. Cavernoma and hematoma were removed. Hemostasis was achieved. Dura was closed. The attached bone flap was then turned upward and reattached using nonresorbable sutures. Postoperatively, the patient had resolution of sensory and motor disturbances on the right half of the body, and coordination was improved in the left limbs. Postoperative imaging confirmed complete removal of the lesion.