Outcome of Suboccipital Decompression with and without Duraplasty in Adults with Chiari I Malformation

Objective: To investigate outcome for Arnold Chiari 1 Malformation (ACM1) patients based on intervention methods, i.e., posterior fossa decompression without duraplasty and with duraplasty in terms of symptomatic and functional improvement Materials and Methods: This study was conducted prospectively over 41 months from January 2013 to May 2016. Patients with confirmed diagnosis of ACM-1 were included in the study. Patients either underwent posterior fossa decompression without duraplasty or with duraplasty, depending upon the severity of tonsillar descent, the presence of syrinx, neurological deficits or hydrocephalous. Data was collected on pre-designed pro forma both pre-operatively and during follow up. Outcome was assessed according to Chicago Chiari Outcome Scale (CCOS). Data analysis was done using SPSS v 22.0. Results: Posterior Fossa Decompression (PFD) without dural opening was performed in 13 patients while in 8 patients duraplasty was performed. Overall mean age was 32.95 ± 5.88 years and mean symptoms duration was 21.62 ± 8.82 months. The most common complaints were headache (76.2%), neck pain (61.9%), hand and arm weakness (47.6%), gait disturbance (47.6%) and cranial nerve dysfunctions (76.2%). The median preop CCOS was 10 ± 1.57 while postoperative CCOS was 13 ± 2.27. There was a significant relief in terms of CCOS improvement in preop and postoperative scores (P = 0.006). The commonest complication was CSF leak in 14.3% of patients. There was no mortality. No recurrent cases were noted during the 41-months study period. Conclusion: Posterior fossa decompression forACM-I is simple and effective. Further studies regarding surgical outcome and development of outcome assessment are required with larger patient cohorts. Abbreviations: CCOS: The Chicago Chiari Outcome Scale. CSF: Cerebrospinal Fluid. CV: Craniovertebral. OPD: Out Patient Department. SD: Standard Deviation. HMC: Hayat Abad Medical Complex. ACM1: Arnold Chain 1 Malformation