Incidence, outcomes, and effect on quality of life of cranial nerve injury in the Carotid Revascularization Endarterectomy versus Stenting Trial

Abstract

Objective: Cranial nerve injury (CNI) is the most common neurologic complication of carotid endarterectomy (CEA) and can cause significant chronic disability. Data from prior randomized trials are limited and provide no health-related quality of life (HRQOL) outcomes specific to CNI. Incidence of CNIs and their outcomes for patients in the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) were examined to identify factors predictive of CNI and their impact on HRQOL.

Methods: Incidence of CNIs, baseline and procedural characteristics, outcomes, and HRQOL scores were evaluated in the 1151 patients randomized to CEA and undergoing surgery ≤30 days. Patients with CNI were identified and classified using case report forms, adverse event data, and clinical notes. Baseline and procedural characteristics were compared using descriptive statistics. Clinical outcomes at 1 and 12 months were analyzed. All data were adjudicated by two neurologists and a vascular surgeon. HRQOL was evaluated using the Medical Outcomes Short-Form 36 (SF-36) Health Survey to assess general health and Likert scales for disease-specific outcomes at 2 weeks, 4 weeks, and 12 months after CEA. The effect of CNI on SF-36 subscales was evaluated using random effects growth curve models, and Likert scale data were compared by ordinal logistic regression.

Results: CNI was identified in 53 patients (4.6%). Cranial nerves injured were VII (30.2%), XII (24.5%), and IX/X (41.5%), and 3.8% had Horner syndrome. CNI occurred in 52 of 1040 patients (5.0%) receiving general anesthesia and in one of 111 patients (0.9%) operated on under local anesthesia (P = .05). No other predictive baseline or procedural factors were identified. Deficits resolved in 18 patients (34%) at 1 month and in 42 of 52 patients (80.8%) by 1 year. One patient died before the 1-year follow-up visit. The HRQOL evaluation showed no statistical difference between groups with and without CNI at any interval. By Likert scale analysis, the group with CNI showed a significant difference in the difficulty eating/swallowing parameter at 2 and 4 weeks (P < .001) but not at 1 year.

Conclusions: In CREST, CNI occurred in 4.6% of patients undergoing CEA, with 34% resolution at 30 days and 80.8% at 1 year. The incidence of CNI was significantly higher in patients undergoing general anesthesia. CNI had a small and transient effect on HRQOL, negatively affecting only difficulty eating/swallowing at 2 and 4 weeks but not at 1 year. On the basis of these findings, we conclude that CNI is not a trivial consequence of CEA but rarely results in significant long-term disability.

Figure 1

Comparison of results for the SF-36 at 2-weeks, 1-month and 1-year. No significant differences noted at any interval between the groups with and without CNI.

Figure 2

Comparison of Likert scale results at 2-weeks, 1-month and 1-year. A significantly worse outcome in Difficulty eating/swallowing was noted for the group with CNI versus without CNI at 2-weeks and 1-month, (p<0.001). At 1-year follow-up there was a non-significant trend toward a worse outcome for the same parameter for the group with CNI, (p=0.0586).