Developments in the treatment of Chiari type 1 malformations over the past decade

• Published in: Journal of spine surgery (Hong Kong) Vol. 4; no. 1; pp. 45 - 54
• Main Authors: Passias, Peter G, Pyne, Alexandra, Horn, Samantha R, Poorman, Gregory W, Janjua, Muhammad B, Vasquez-Montes, Dennis, Bortz, Cole A, Segreto, Frank A, Frangella, Nicholas J, Siow, Matthew Y, Sure, Akhila, Zhou, Peter L, Moon, John Y, Diebo, Bassel G, Vira, Shaleen N
• Format: Journal Article
• Language: English
• Published: China AME Publishing Company 01.03.2018
• Subjects: Original Study; Chiari malformations type 1 (CM-1); Chiari; complication rates; spinal decompression; pediatrics
• ISSN: 2414-469X; 2414-4630
• DOI: 10.21037/jss.2018.03.14

Chiari malformations type 1 (CM-1), a developmental anomaly of the posterior fossa, usually presents in adolescence or early adulthood. There are few studies on the national incidence of CM-1, taking into account outcomes based on concurrent diagnoses. To quantify trends in treatment and associated diagnoses, as retrospective review of the Kid's Inpatient Database (KID) from 2003-2012 was conducted. Patients aged 0-20 with primary diagnosis of CM-1 in the KID database were identified. Demographics and concurrent diagnoses were analyzed using chi-squared and -tests for categorical and numerical variables, respectively. Trends in diagnosis, treatments, and outcomes were analyzed using analysis of variance (ANOVA). Five thousand four hundred and thirty-eight patients were identified in the KID database with a primary diagnosis of CM-1 (10.5 years, 55% female). CM-1 primary diagnoses have increased over time (45 to 96 per 100,000). CM-1 patients had the following concurrent diagnoses: 23.8% syringomyelia/syringobulbia, 11.5% scoliosis, 5.9% hydrocephalus, 2.2% tethered cord syndrome. Eighty-three point four percent of CM-1 patients underwent surgical treatment, and rate of surgical treatment for CM-1 increased from 2003-2012 (66% to 72%, P<0.001) though complication rate decreased (7% to 3%, P<0.001) and mortality rates remained constant. Seventy percent of surgeries involved decompression-only, which increased neurologic complications compared to fusions (P=0.039). Cranial decompressions decreased from 2003-2012 (42.2-30.5%) while spinal decompressions increased (73.1-77.4%). Fusion rates have increased over time (0.45% to 1.8%) and are associated with higher complications than decompression-only (11.9% 4.7%). Seven point four percent of patients experienced at least one peri-operative complication (nervous system, dysphagia, respiratory most common). Patients with concurrent hydrocephalus had increased; nervous system, respiratory and urinary complications (P<0.006) and syringomyelia increased the rate of respiratory complications (P=0.037). CM-1 diagnoses have increased in the last decade. Despite the decrease in overall complication rates, fusions are becoming more common and are associated with higher peri-operative complication rates. Commonly associated diagnoses including syringomyelia and hydrocephalus, can dramatically increase complication rates.