Mass Effect Due to Hypertrophic Pericranial Flap in the Reconstruction of Dural Defect

Objective To present a case of symptomatic mass effect caused by engorgement of a vascularized pericranial flap in the repair of dural defect secondary to parasagittal meningioma surgical excision, in order to expose a potential complication from this reconstruction technique. Case A 62-year-old man with a left medial-third type 1 of Sindou's classification parasagittal meningioma underwent complete Simpson 1 surgical excision. For the reconstruction of the dural defect, a vascularized pericranial flap was sutured using water-sealed technique. On postsurgical day 2, the patient developed progressive neurologic impairment characterized by stupor. Magnetic resonance imaging stroke sequence revealed what appears to be an extradural collection not visualized on an immediate postsurgical computed tomographic scan. In surgical reexploration, we found an engorged pericranial flap causing direct compression to the parenchyma without the presence of additional hematoma in the surgical field. Resolution The pericranial flap needed to be excised, and the dural defect was repaired using synthetic material. No permanent neurologic deficit was documented at 6-month follow-up. Conclusion We hypothesized that pericranial flap was strangulated because of final bone flap replacement so that venous outflow was compromised. This complication can be prevented if adequate drilling of the inner table at the edge of the craniotomy and at the outer table of the bone flap is performed just at the entry zone of pericranium flap pedicle to avoid a 90° angle of entry resulting in vascular congestion.