Stenting of symptomatic M1 stenosis of middle cerebral artery: an initial experience of 40 patients.

Objective: To assess the safety and clinical efficacy of stenting for patients with symptomatic M1 stenosis of middle cerebral artery (MCA), and to assess the significance of classification based on location, morphology, and access of intracranial stenosis (LMA classification) in MCA stenting.

Methods: Forty patients with 42 symptomatic M1 stenoses refractory to medical therapy were enrolled in this study. The lesions were situated at M1 trunk (n=13), M1 origin (n=12), and M1 bifurcation (n=17), respectively, which were classified into type N (nonbifurcation lesions, n=13) and type A (prebifurcation, n=11), B (postbifurcation, n=14), C (lesion across the nonstenotic ostium of its branch, n=1), D (across the stenotic ostium of its branch, n=2), F (combinative lesions of prebifurcation and its small branch ostium, n=1) locations, morphologically into type A (n=15), B (n=23) and C (n=4) lesions, and into type I (mild-to-moderate tortuosity and smooth access, n=17), II (severe tortuosity and/or irregular arterial wall, n=18), and III (excessively severe tortuosity, n=7) accesses.

Results: The technical successful rate was 97.6% for total lesions and 100%, 100%, and 85.7% for types I, II, and III accesses, respectively. The total complication rate was 10%. The mortality was 2.5% (1/40 patients), and 0%, 0%, and 25% for types A, B, and C lesions, respectively. During the median 10 months follow-up, there was no recurrence of transient ischemic attack or stroke in 38 available patients. Among 8 stenting vessels of seven patients with six-month follow-up angiography, 7 showed good patency and one showed restenosis.

Conclusions: Stenting appears to be an effective and feasible therapy for symptomatic M1 stenoses, but also appears to have the higher periprocedural complications, which need strict procedural and periprocedural management to reduce the mortality and morbidity. The LMA classification seems to be helpful to work out the individual therapy and predict the results of stenting. A further study is needed to confirm the benefits of stenting of MCA stenosis.