Evaluation of the apposition in unruptured aneurysms treated with flow diverters by optical coherence tomography: Preliminary clinical experience

BACKGROUND: The risk of perioperative stroke and the rate of occlusion of long-term aneurysms in the treatment of unruptured aneurysms with flow diverters (FDs) are affected by stent apposition. Optical coherence tomography (OCT) may be an optional technique in evaluating apposition. PURPOSE: To explore the feasibility of the OCT imaging technique in evaluating stent apposition in the clinical application of the FD for unruptured aneurysms. METHODS: OCT and Vaso CT were used in patients with indications for surgery to treat unruptured aneurysms with the FDs, to evaluate the apposition of the FDs after fully released, and to analyze OCT images for FDs apposition and compare with corresponding Vaso CT images. RESULTS: A total of four patients were enrolled, and OCT found malapposition after FDs placement in all four patients, and the maximum gap between the stent and vascular wall ranged from 0.68 to 1.95 mm and the length of malapposition ranged from 1.80 to 7.40 mm. However, Vaso CT found malapposition only in two of the four patients and missed malapposition near aneurysm in all three patients treated by the FD combined with coiling and could not accurately evaluate the maximum gap and the length of the malapposition. CONCLUSION: The optical coherence tomography technique is a possible approach to evaluate apposition after the treatment of unruptured aneurysms by the FDs.