Orbitozygomatic Transsylvian Resection of a Craniopharyngioma: A Step-by-Step Guide.

Adamantinomatous craniopharyngioma (ACP) is a rare sellar region tumor seen in 0.5-2 cases per million persons each year,1 presenting a bimodal distribution that peaks at 5-15 years in children and 45-60 years in adults.2 Arising from embryonic remnants of the Rathke pouch epithelium, ACPs are associated with calcifications in 90% of cases and grow cranially toward the floor of the diencephalon.1 Craniopharyngiomas are benign but locally aggressive tumors, with microsurgery being the best chance of cure.3 The natural history is to compress the optic apparatus and hypothalamic-pituitary axis as they expand, with a propensity to encase the carotids. Endoscopic transbasal approaches have gained wide acceptance in the management of these tumors.4-6 However, open microsurgical approaches via pterional and orbitozygomatic craniotomies afford wider visualization of different corridors that help mitigate the surgical risks.7-9 The orbitozygomatic craniotomy allows lesions that extend above the optic chiasm to be safely approached from an inferior-to-superior corridor.9 The wide exposure of the basal arachnoid cisterns allows protection of the lenticulostriate perforators during resection.8-11 We demonstrate a step-by-step orbitozygomatic approach with dissection of the sylvian, carotid, carotid-oculomotor, chiasmatic, and lamina terminalis cisterns that allowed safe resection of a third ventricular ACP. The patient was a male in his 70s, who presented with progressive headaches and visual impairment. Magnetic resonance imaging showed a multicystic suprasellar lesion extending through the third ventricle. The surgery was performed with no complication (Video 1). Postoperative vision stabilized, and magnetic resonance imaging showed complete resection.

Case report: Delayed outflow obstruction of a DVA: A rare complication of brainstem cavernoma surgery.

Introduction: Developmental venous anomalies (DVAs) are considered variants of normal transmedullary veins. Their association with cavernous malformations is reported to increase the risk of hemorrhage. Expert consensus recommends meticulous planning with MR imaging, use of anatomical "safe zones", intraoperative monitoring of long tracts and cranial nerve nuclei, and preservation of the DVA as key to avoiding complications in brainstem cavernoma microsurgery. Symptomatic outflow restriction of DVA is rare, with the few reported cases in the literature restricted to DVAs in the supratentorial compartment. Case: We present a case report of the resection of a pontine cavernoma complicated by delayed outflow obstruction of the associated DVA. A female patient in her 20's presented with progressive left-sided hemisensory disturbance and mild hemiparesis. MRI revealed two pontine cavernomas associated with interconnected DVA and hematoma. The symptomatic cavernoma was resected via the infrafacial corridor. Despite the preservation of the DVA, the patient developed delayed deterioration secondary to venous hemorrhagic infarction. We discuss the imaging and surgical anatomy pertinent to brainstem cavernoma surgery, as well as the literature exploring the management of symptomatic infratentorial DVA occlusion. Conclusion: Delayed symptomatic pontine venous congestive edema is extremely rare following cavernoma surgery. DVA outflow restriction from a post-operative cavity, intraoperative manipulation, and intrinsic hypercoagulability from COVID-10 infection are potential pathophysiological factors. Improved knowledge of DVAs, brainstem venous anatomy, and "safe entry zones" will further elucidate the etiology of and the efficacious treatment for this complication.