Classification of internal carotid artery injuries during endoscopic endonasal approaches to the skull base

Background: Internal carotid artery (ICA) injuries are a major complication of endoscopic endonasal approaches (EEAs), which can be difficult to manage. Adding to the management difficulty is the lack of literature describing the surgical anatomical classification of these types of injuries. This article proposing a novel classification of ICA injuries during EEAs. Methods: The classification of ICA injuries during EEAs was generated from the review of the literature and analysis of the main author observation of ICA injuries in general. All published cases of ICA injuries during EEAs in the literature between January 1990 and January 2020 were carefully reviewed. We reviewed all patients’ demographic features, preoperative diagnoses, modes of injury, cerebral angiography results, surgical and medical management techniques, and reported functional outcomes. Results: There were 31 papers that reported ICA injuries during EEAs in the past three decades, most studies did not document the type of injury, and few described major laceration type of it. From that review of the literature, we classified ICA injuries into three main categories (Types I-III) and six sub-types. Type I is ICA branch injury, Type II is a penetrating injury to the ICA, and Type III is a laceration of the ICA wall. The functional neurological outcome was found to be worse with Type III and better with Type I. Conclusion: This is a novel classification system for ICA injuries during EEAs; it defines the patterns of injury. It could potentially lead to advancements in the management of ICA injuries in EEAs and facilitate communication to develop guidelines.