Dura Management Strategies in the Surgical Treatment of Adult Chiari Type I Malformation: A Retrospective, Multicenter, Population-Based Parallel Cohort Case Series

Abstract

BACKGROUND:Symptomatic Chiari I malformation is treated with suboccipital decompression and C1 laminectomy. However, whether the dura should be opened (durotomy) or enlarged with a graft (duraplasty) remains unclear.OBJECTIVE:To compare outcomes in adult Chiari I malformation patients treated with duraplasty, durotomy, or without dural opening (“mini-decompression”).METHODS:A retrospective, multicenter, population-based cohort study was performed of all adult patients surgically treated for a Chiari I malformation at 3 regional neurosurgical centers between 2005 and 2017. Three different dura management strategies were favored by the participating hospitals, with data stratified accordingly. The primary outcome was measured using the Chicago Chiari Outcome Scale (CCOS), dichotomized into favorable (CCOS ≥13) or unfavorable (CCOS ≤12). Propensity score matching was used to adjust for potential confounders in outcome comparisons.RESULTS:In total, 318 patients were included, of whom 52% were treated with duraplasty, 37% with durotomy, and 11% with mini-decompression. In total, 285 (90%) showed a favorable surgical outcome (CCOS ≥13). Duraplasty was associated with more favorable CCOS and shorter hospital stay compared with durotomy, both in unadjusted (93% vs 84%. P = .018 and 6.0 vs 8.0 days, P < .001) and adjusted analyses (92% vs 84%, P = .044 and 6.0 vs 8.0 days, P < .001). Mini-decompression was excluded from the adjusted analyses because of its small sample size.CONCLUSION:In this study of adult Chiari I malformation, posterior fossa decompression with duraplasty was associated with more favorable postoperative outcome, as determined by the CCOS, compared with posterior fossa decompression with durotomy alone.

Commentary: Dura Management Strategies in the Surgical Treatment of Adult Chiari Type I Malformation: A Retrospective, Multicenter, Population-Based Parallel Cohort Case Series

“…Importantly, the advantage of durotomy lies in re-establishing the normal CSF circulation by providing a wide exposure to allow for microlysis of adhesions that can tether the tonsils, brainstem, spinal cord, and posterior inferior cerebellar artery, along with tonsillar reduction when needed. 3 In the current study, 1 both duraplasty and durotomy alone were accompanied by a sharp arachnoid membrane dissection.…”

“…T he authors should be commended for presenting a unique, retrospective, population-based cohort study of patients treated surgically for Chiari type I malformation at 3 neurosurgical centers in Sweden. 1 Of 318 adult patients enrolled, 166 (52%) treated with posterior fossa decompression (PFD) and duraplasty were compared with 118 (37%) treated with PFD and durotomy alone, with only 34 (11%) undergoing PFD alone, without durotomy. PFD bone-only patients were excluded due to their low sample size.…”

Predictors of reoperation for spinal disorders in Chiari malformation patients with prior surgical decompression

“…[ 4 , 5 ] The goals of surgery are to relieve pressure on the relevant hindbrain structures and to restore the normal cerebrospinal fluid (CSF) flow across the craniovertebral junction, which is most commonly done by decompression of the posterior fossa and foramen magnum. [ 5 6 7 ] Reasons for CM reoperation include persisting neurological symptoms, inadequate initial decompression, faulty stent placements, and development of postoperative complications. [ 8 , 9 ]…”

Post-Operative Complications after Foramen Magnum Decompression with Duraplasty Using Different Graft Materials in Adults Patients with Chiari I Malformation: A Systematic Review and Meta-Analysis

“…a Kristiansson et al[35] reported the use of sutured biological patch with addition of an overlayed synthetic patch; b Bowers et al[25] reported 128 procedures on 119 patients.…”