Endovascular Management of Acute and Delayed Internal Carotid Artery Injuries Secondary to Transsphenoidal Resection of Pituitary Adenoma

Introduction: Internal carotid artery (ICA) injury is a rare, but severe complication of transsphenoidal pituitary surgery. Several endovascular techniques are available for the treatment of these injuries, including many that spare the injured vessel. The aim of this study was to review a single institutions experience with endovascular treatment of ICA injuries, highlighting cases that illustrate the advantages and constraints of the different techniques. Methods: A retrospective review was performed of 576 transsphenoidal pituitary adenoma resection to identify baseline demographic, operative, and endovascular treatment characteristics of cases in which there was intraoperative ICA injury, and evaluate postendovascular treatment outcomes. Patients transferred to our institution for management of ICA injury were also evaluated for postendovascular treatment outcomes. Results: A total of 20 cases were identified (mean age, 46.3 years; mean follow-up, 43.4 months [range, 1–107 months]) who received endovascular treatment for ICA injury. Five ICA injuries occurred at our institution (5/576; 0.9%), while two had surgery at other institutions. Four cases had ICA injury noted at the time of surgery, while three were diagnosed in a delayed fashion. Emergent ICA sacrifice was performed in three patients who suffered acute ICA injury during surgery and demonstrated good collateral circulation on balloon test occlusion. Two of these patients suffered no permanent neurological sequela from the ICA occlusion, while one patient experienced a small permanent visual field defect. Vessel sparing endovascular repair was performed in four patients. One patient received coiling without stent-assistance for an 18 mm, narrow necked pseudoaneurysms discovered 2 months after surgery, which later required stent-assisted coiling and Onyx embolization for recurrence before ultimately having complete ipsilateral ICA occlusion without neurological deficit at 36 months after initial endovascular treatment. One patient with significant intracranial atherosclerosis and compromised collateral circulation received stent-assisted coiling for a 5 mm pseudoaneurysm discovered intraoperatively. In this case, endovascular treatment was deferred for 3 days because of the risk of antiplatelet/anticoagulation therapy in the postoperative period; however, the patient had significant baseline comorbidities which contributed to expiration from cerebral infarction 22 days after stenting. The Pipelinetm Embolization Device was for two patients, one who received delayed treatment 15 days after ICA injury and a second patient 20 years after ICA injury and pseudoaneurysm coiling. Neither patient developed neurovascular complications associated with the ICA injury or endovascular treatment within the available follow-up (16 and 9 months, respectively). Conclusion: Endovascular treatments including vessel sacrifice, coiling (with or without stent assistance), and flow diversion allow for a tailored approach to ICA injury management after transsphenoidal surgery. If the injury is acute and collateral flow is good, vessel sacrifice is well-tolerated and effective. Decision making for patients with acute bleeding and poor collateral flow is more challenging, and may require delayed vessel preservation and/or covered stenting when the anatomy allows. Flow diversion may be the procedure of choice for patients with pseudoaneurysms that present in a delayed fashion. Multiple factors such as vascular anatomical features, injury characteristics, baseline comorbidity, and risk of antiplatelet/anticoagulation therapy should also be used to guide selection of the most appropriate treatment.