Cavernous Internal Carotid Artery Aneurysm: Exsanguinating Iatrogenic Internal Carotid Artery Injury During Transsphenoidal Surgery for Pituitary Macroadenoma – Packing, Transvenous Coil Occlusion of a Carotid Cavernous Sinus Fistula, and Repair of a Carotid Pseudoaneurysm with a Flow-Diverter Stent

Abstract

Transsphenoidal surgery for pituitary adenoma is associated with low rates of morbidity and mortality; however, complications from internal carotid artery (ICA) injury can lead to disability or even death. Patient outcome depends primarily on the ability to recognize and manage these complications promptly. A 22-year-old patient was transferred to our center after massive epistaxis that began during the early stages of a transsphenoidal intervention for a non-secreting pituitary macroadenoma. She presented with headaches, visual disturbance, and moderate hyperprolactinemia (pituitary stalk compression syndrome). Intraoperative hemorrhage was massive and partially controlled with gauze tampons and a nasal Foley catheter. Despite these measures, proptosis developed and active epistaxis persisted. After a 30-minute transfer process, the patient was admitted directly to our interventional angiography room. Under general anesthesia, angiography of both ICAs and vertebral arteries (VA) demonstrated a right ICA cavernous pseudoaneurysm, a direct high-flow carotid cavernous sinus fistula (CCF), and a complete circle of Willis. The patient underwent emergent transient balloon occlusion of the injured ICA segment to achieve hemorrhage control, followed by transvenous endovascular coil occlusion of the CCF through the superior and inferior petrosal sinuses with coils and Onyx under intermittent carotid occlusion/protection. She stabilized rapidly and was discharged after 7 days without ophthalmological signs of carotid cavernous sinus fistula. Angiographic follow-up was obtained after 3 weeks, and the right ICA pseudoaneurysm was treated with implantation of a flow-diverter stent. Angiographic follow-up obtained 3 months later confirmed reconstruction of the injured artery with complete exclusion of the pseudoaneurysm. One month later, she underwent further uneventful transsphenoidal surgery for removal of the pituitary tumor. The staged strategy of emergent hemorrhage control followed by delayed definitive arterial reconstruction with flow-diverter stents as the endovascular management of iatrogenic carotid pseudoaneurysms is the main topic of this chapter.