Massive cavernous sinus bleeding secondary to Valsalva maneuver in endoscopic pseudomeningocele surgery: a case report

Ventral skull base pseudomeningoceles (PMCs) are extremely rare. We report a life-threatening intraoperative complication of the endoscopic approach that has not been previously documented. A 64-year-old man presented with left-sided bloody rhinorrhea. Radiologic evaluation revealed a giant cystic lesion occupying nearly the entire ventral skull base, consistent with a PMC. Endonasal endoscopic surgery was planned. Since the site of cerebrospinal fluid leakage could not be identified intraoperatively, we requested the anesthesiologist to perform the Valsalva maneuver. This resulted in profuse bleeding from the left cavernous sinus (CS). Hemostasis was achieved, and the skull base defect was successfully repaired. Untreated skull base PMCs that erode the medial wall of the CS may progressively enlarge and pose a life-threatening risk. This case highlights the risk of CS hemorrhage during intracranial pressure-raising maneuvers such as the Valsalva maneuver in PMCs that erode the medial cavernous wall. Surgeons should remain alert to this potential complication in this type of high-risk case.