Delayed complete remission of hemifacial spasms following microvascular decompression and the implications for optimal time of revision surgery

Abstract

Background: Microvascular decompression (MVD) is an effective method for directly treating hemifacial spasms (HFS). The timing for the consideration of failed MVD and reoperation has been paradoxical. Objective: This study aimed to investigate the delayed complete remission of HFS in terms of prevalence rate, duration between surgery and delayed complete remission, and predictive factors. Methods: A hundred patients with HFS who underwent MVD from 2012–2021 were enrolled in the study. All HFS occurred as a result of compression of the facial nerve by adjacent blood vessels. Clinical information, intraoperative findings, and surgical outcomes were incorporated for data analysis. Results: In the first week after MVD, 67 of 100 patients achieved complete remission of HFS, while the remaining 33 had incomplete remission. In long-term follow-up, 26 individuals gradually developed delayed complete remission with a median duration of 9.1 months. Finally, 86 of 100 patients achieved complete long-term remission. Recurrent HFS and incomplete remission were found in 7 and 7 patients, respectively. Factors associated with postoperative complete remission in the first week were a severe degree of facial nerve compression (p = 0.047, OR 2.75, 95% CI 1.01–7.40), with long-term complete remission was left-sided HFS (p = 0.012, OR 5.73, 95% CI 1.47–22.36), and with the appearance of delayed complete remission was the prolonged duration of HFS at least 3 years before MVD (p = 0.046, OR 3.75, 95% CI 1.03–13.76). Transient facial paresis was found in 11% of the patients. Of them, facial nerve function recovered completely in all cases. Conclusions: A delayed complete remission of HFS could be expected in long-term follow-up after MVD and is probably related to a longer duration of HFS before surgery. Unnecessary reoperation should be avoided in the early years following the first surgery.