Foramen Magnum Decompression for Chiari Malformation Type 1: Is There a Superior Surgical Technique?

Abstract

A retrospective analysis of FMDs performed between 2012-2017 for Chiari 1 in one institution. Three types of operations were performed: 1) bone decompression without opening the dura, 2) bone decompression and opening of dura without duroplasty. 3) opening of dura with duroplasty. We compared the post-operative symptoms and revision rates between these 3 techniques. 168 patients had 185 FMDs. Of the 168 primary operations, in 66 the dura was not opened, in 86 the dura was opened without a duroplasty and in 16 a duroplasty was performed. 17 out of 185 operations were revision surgery. For primary procedures the revision rates were: 12 (18%) if the dura was not opened, 4 (5%) if the dura was left open and 1 (6%) when duroplasty was performed. Severe post-operative headache and nausea occurred in 2 (3%) patients after the dura was not opened, 4 (25%) patients after primary duroplasty and 64 (74%) patients after primary durotomy. We found that the rate of revision surgery was highest in the group who had bony decompression without dural opening. The rate of post-operative headache and nausea was highest in the durotomy group. Overall duroplasty had the best results.