Posterior Cerebral Artery Pseudoaneurysm, a Rare Complication of Pituitary Tumor Transsphenoidal Surgery: Case Report and Literature Review.

Endoscopic endonasal transsphenoidal surgery for pituitary tumors has been the standard therapy for decades. This approach offers surgeons an effective, safe, and wide exposure to the pituitary gland, with a relatively low mortality rate and acceptable complication rates. However, severe complications, including cerebrospinal fistula, meningitis, neural component injury, and vascular injury, may occur. One of the most common and severe complications is carotid artery injury; however, only 2 posterior cerebral artery injuries with pseudoaneurysm formation have been reported previously. One of them received bypass surgery and recovered well, but the other received endovascular treatment and died of intracranial hypertension. Herein, we report a rare case of iatrogenic pseudoaneurysm formation with hemorrhage after transsphenoidal surgery, in which tumor traction-related adjacent vessel injury was most likely. Aneurysm clipping, vascular bypass, and embolization are considered reasonable choices depending on the patient's condition for iatrogenic aneurysm formation. In our case, no surgical or endovascular intervention was performed, and the aneurysm healed spontaneously 3 weeks later.