Management of postoperative internal carotid artery intimal flap after carotid endarterectomy: a cohort study and systematic review

OBJECTIVE Postoperative internal carotid artery (ICA) intimal flap (IF) is a potential complication after carotid endarterectomy (CEA) for carotid artery stenosis. There are no clear recommendations in the current literature on the management of this condition due to sparse evidence. Some authors advocate carotid stent placement or reoperation, while others suggest watchful waiting. The aim of this study was to analyze incidence and management strategies of postoperative ICA-IF, and moreover, to put these findings into context with a systematic literature review. METHODS The authors retrospectively reviewed all consecutive CEA cases performed at the University Hospital of Bern over a decade (January 2008 to December 2018). The incidence of postoperative ICA-IF, risk factors, management strategies, and outcomes were analyzed. These results were put into context with a systematic review following the PRISMA guidelines. RESULTS A total of 725 CEAs were performed between January 2008 and December 2018. Postoperative ICA-IF was detected by routine duplex neurovascular ultrasound (NVUS) in 13 patients, corresponding to an incidence rate of 1.8% (95% CI 1.0%-3.1%). There were no associated intraluminal thrombi on the detected IF. Intraoperative shunt placement was used in 5.6% and one or more intima tack sutures were performed in 42.5% of the 725 cases. There was no significant association between intraoperative shunt placement and the occurrence of an IF (p > 0.99). Two patients (15.4%) with IF experienced a transient postoperative neurological deficit (transient ischemic attack). In these cases, the symptoms resolved spontaneously without any interventions or change in the antiplatelet regimen. All other cases (84.6%) with IF were asymptomatic. In 1 patient (7.7%) with IF, the antiplatelet treatment was switched from a mono-to a dual-antiaggregating regimen because the IF led to a stenosis > 70%; this patient remained asymptomatic. All cases of IFs were managed conservatively with close radiological follow-up evaluations, without reoperation or stenting of the ICA. All 13 IFs vanished spontaneously after a mean duration of 6.9 months (median 1.5 months, range 0.5-48 months). A systematic literature review revealed a postoperative ICA-IF incidence of 3.0% (95% CI 2.1%-4.1%) with relatively heterogenous management strategies. CONCLUSIONS Postoperative ICA-IF is a rare finding after CEA. Conservative therapy with close NVUS follow-up evaluations appears to be an acceptable and safe management strategy for asymptomatic IFs without associated intraluminal thrombi.