Cranial nerve injuries post carotid endarterectomy: A 15-year prospective study with routine otolaryngologist and neurological evaluation.

Abstract

Objective: The aim of this prospective monocentric cohort study was to analyze the risk of otolaryngologist-assessed cranial nerve injuries (CNIs) following carotid endarterectomy (CEA) in our academic center during a 15-year period, and to identify possible risk factors for CNI development.

Methods: From January 2007 to December 2022, 3749 consecutive CEAs were performed and their data prospectively recorded in a dedicated database. CNIs were assessed and defined according to a standardized protocol. Instrumental ear, nose, and throat (ENT) evaluations were conducted within 30 days before intervention and before discharge. Preoperative neurological assessments were carried out in all patients with symptomatic carotid stenosis, whereas postoperative neurological evaluations were performed in all patients. Patients with newly onset CNIs underwent follow-up assessments at 30 days and, if necessary, at 6, 12, and 24 months. Perioperative results, including mortality, major central neurological events, and postoperative CNIs, were analyzed. Regression or persistence of lesions during follow-up visits was assessed, and multivariate analysis (binary logistic regression) was conducted to evaluate clinical, anatomical, and surgical technique factors influencing the occurrence of CNIs.

Results: CEAs were performed more frequently in male patients (2453 interventions; 65.5%) than in females (1296 interventions; 34.5%). The interventions were performed in asymptomatic patients in 3078 cases (82%). In 66 cases, the interventions followed a previous ipsilateral CEA. At preoperative ENT evaluation, no cases of ipsilateral pre-existent CNI were recorded. The 30-day stroke and death rate was 1%. In 113 patients (3%), a postoperative neck bleeding requiring surgical revision and drainage was noted. Pre-discharge ENT evaluations identified 259 motor CNIs, accounting for 6.9% of the entire study group. Eighteen patients had lesions in more than one cranial nerve. ENT and neurological evaluations at 30 days showed the complete resolution of 161 lesions, whereas in 98 cases (2.6%), the CNI persisted. At 1 year, the rate of persistent CNI was 0.4% (10 patients), whereas at 2 years, it was 0.25% (6 cases), in all but one asymptomatic. At multivariate analysis, urgent intervention in unstable patients, secondary intervention, a clamping time >40 minutes, a hematoma requiring revision, and a postoperative stroke were independent predictors of CNIs.

Conclusions: Data from this prospective monocentric cohort study showed that the occurrence of CNI following CEA was low, even when an independent multi-specialist evaluation was performed. The percentage of persistent lesions at 2 years was negligible and, in most cases, asymptomatic.