Prosthesis used in microvascular decompressions: a multicenter survey in Japan focusing on adverse events

Summary The purpose of this study was to investigate the characteristics of materials used as prostheses for microvascular decompression surgery (MVDs) in Japan and their possible adverse events (AEs) to determine preferable materials for MVDs. A questionnaire was sent to all members of the Japanese Society for MVDs, and answers were obtained from 59 institutions. Among a total of 2789 MVDs, 1088 operations for trigeminal neuralgia, 1670 for hemifacial spasm, and 31 others, including 117 re-operations, were performed between April 2011 and March 2014. Non-absorbable material was used in 96.5% of MVDs, including polytetrafluoroethylene (PTFE) (80.5%), polyurethane (11.9%), expanded PTFE (2.1%), and silk thread (1.47%). The usage of absorbable materials, including fibrin glue (87.5%), cellulose (13.5%), gelatin (4,77%), and collagen (1.76%), was reported. The major combinations were PTFE with fibrin glue (58.7%) followed by PTFE alone (7.60%). Eighty-eight AEs in 85 (3.2%) cases were reported among 2672 first operations. AEs included 51 central nervous system dysfunctions, 15 wound infections/dehiscence, and 10 others, that were presumed to be related to the intraoperative procedure. Among relatively high-volume, moderate-volume, and low-volume centers, there were no significant differences in the frequency of AEs (P=0.077). Tissue-prosthesis adhesion and/or granuloma formation were reported in 13 cases out of 117 re-operations. The incidence of adhesion-related recurrence was 11.1% of all re-operations. In conclusion, the number of AEs was quite low in this survey, and intradural use of any prosthesis reported in this paper might be justified. However, further development of easily handled and less-adhesive prosthesis materials is awaited.