Comparison of the Surgical Results for Foramen Magnum Decompression with and without Duraplasty in Chiari Malformation Type 1

Abstract

AIM: The surgical results for foramen magnum decompression (FMD) with and without duraplasty in Chiari Malformation type 1 (CM-1) were compared retrospectively. MATERIAL and METHODS: Thirty-nine cases of CM-1 with and without syringomyelia (SM) were included.There were 18 patients in the non-duraplasty and 21 in the duraplasty group. Syringomyelia, tonsillar herniation (TH), preoperative symptom duration, and postoperative SM size were compared. RESULTS: No significant difference was found between improvement in the duraplasty group (81%) and the non-duraplasty group (61.1%). In cases whose symptom duration was 0-36 months, improvement in the duraplasty group (93%) was significantly better than in the non-duraplasty group (50%) (p<0.01). The rate of syrinx regression was 92.3% in the duraplasty group and 12.5% in the non-duraplasty group (p<0.05). In cases with SM, the improvement was 21.4% in the non-duraplasty group compared to 78.6% in the duraplasty group (p=0.056). In cases with TH greater than 10 mm, the improvement was 66.7% in the non-duraplasty group, whereas all six cases (100%) in the duraplasty group had improved. CONCLUSION: In SM associated cases, cases with TH greater than 10 mm, and whose symptom duration is less than 36 months, duraplasty is a more reliable choice despite a slightly higher rate of complications.