Radiation-Induced Skull Base Carotid Artery Blowout Syndrome Presenting with Oral Hemorrhage: Carotid Reconstruction Using Flow Diverter Stent-Assisted Coiling; Good Immediate Clinical and Angiographic Results Followed by Arterial Occlusion

Carotid blowout syndrome (CBS) is an uncommon but feared complication in patients treated for head and neck cancer. CBS results from necrosis of the arterial wall, which follows tumor invasion of the carotid artery wall, resection, irradiation, infection, or a combination of these factors. In most series, radiotherapy is considered the main predisposing factor for the development of CBS, which is thus sometimes called postirradiation CBS. The contribution of radical neck dissection to the development of CBS is still unclear. There are three categories of CBS: threatened (eventual hemorrhage is inevitable from a visibly exposed carotid vessel), impending (episodic sentinel hemorrhages from a pseudoaneurysm that resolve spontaneously or with packing), and acute (profuse hemorrhage, not confined by a pseudoaneurysm, that is not well-controlled with packing). Management of this entity frequently requires evaluation of oncological, surgical, and endovascular considerations. Among the endovascular options, deconstructive and stent-assisted reconstructive techniques have been described. We present a case of impending CBS in a patient previously irradiated for oropharyngeal carcinoma. The CBS was treated using multiple flow diverter stents (FDSs), leading to an excellent clinical outcome. A 72-year-old man with a history of oropharynx malignancy treated using chemotherapy and intensity-modulated radiation therapy (IMRT) 8 years earlier experienced two episodes of oral hemorrhage within 4 h. Oncologists considered him in remission, and despite hoarseness, ageusia, fatigue, chronic anemia, and the requirement to receive all nutrition via gastrostomy, the patient had a remarkably independent and fully productive life. After the first hemorrhage, he was admitted to the emergency department of a local medical center, where he underwent cranial CT and CTA that revealed a large prepetrous right internal carotid artery (ICA) pseudoaneurysm and incomplete circle of Willis. The patient then had a second hemorrhage and was urgently transferred to our facility for treatment. His neurological history was unremarkable except for postradiation injury to the cranial base and neck structures. The patient was admitted fully conscious with no motor or sensory alterations in his limbs. The patient was loaded with aspirin and clopidogrel via gastrostomy and immediately transferred to our neurocath lab upon arrival at our hospital. After confirmation of antiplatelet effects (112 platelet reactivity units [PRU]), the patient was placed under general anesthesia. At catheter angiography, a 12 mm prepetrous right ICA pseudoaneurysm pointing medially was seen. The pseudoaneurysm had no active leak. Evaluation of the carotid and vertebral arteries confirmed an incomplete circle of Willis and suggested that the patient was not a candidate for carotid occlusion. The pathological process affected a tortuous arterial segment (skull base) and limited the possibility of using stiff-covered stents. We thus decided to exclude the pseudoaneurysm by coiling to control the impending possibility of massive rebleeding. The implant of telescoped FDSs assisted coil occlusion. Stents not only assisted the mechanical implant of coils but aimed at reinforcing the segmental arterial injury (FDS-assisted coiling and arterial remodeling strategy). The FDSs were expanded utilizing balloon angioplasty and the implant of a balloon-expandable stent at the proximal petrous bend. The patient tolerated the procedure without complications and was extubated 3 h after the introducer sheath was manually removed. The day after the intervention, he was transferred back to his original facility with the recommendation of dual antiplatelet therapy for 6 months, followed by 100 mg acetylsalicylic acid (ASA) and 80 mg atorvastatin per os daily for life. The patient was discharged home on postoperative day 6 and readmitted 28 days later with mild and transient left leg weakness. A new CTA revealed occlusion of the artery at the level of the stent construct. Clopidogrel, antihypertensive, and diuretic medications were discontinued, and the patient was discharged after 48 h. At the 8-month clinical follow-up, the patient remained clinically and neurologically stable with no further ischemic episodes or hemorrhages. This chapter describes a poorly explored therapeutic strategy, the use of coiling and FDS implant to manage CBS. We found this treatment straightforward, uncomplicated, and effective in preventing hemorrhagic and ischemic events. We describe the therapeutic procedure and present a glimpse into some controversies and ongoing debates.