General Session: Pediatric Spine - Hall F

Presented by: L. Steinmetz

Author(s):

P. Passias(1), A. Pyne(1), S. Horn(1), G. Poorman(1), M. Janjua(1), D. Vasquez-Montes(1), N. Frangella(1), C. Bortz(1), F. Segreto(1), D. Ge(1), M. Siow(1), A. Sure(1), P. Zhou(1), J. Moon(1), B. Diebo(2), S. Vira(1)

(1) New York University Langone Orthopedic Hospital, Division of Spinal Surgery, New York, NY, United States
(2) SUNY Downstate Medical Center, Department of Orthopaedic Surgery, Brooklyn, NY, United States

Abstract

Introduction: Chiari malformations type I (CM-I), a developmental anomaly of the posterior fossa, usually presents in adolescence or early adulthood. There are few studies on the national incidence of CM-I, taking into account outcomes based on concurrent diagnoses. The aim of this study is to quantify trends in Chiari malformations type 1 treatment and associated diagnoses.

Methods: Retrospective review the prospectively collected Kids' Inpatient Database (KID) from 2003-2012. Patients with a primary diagnosis of CM-I (ICD9-CM 348.4) ages 0-20 in the KID database were identified. Demographics and concurrent diagnoses were analyzed using chi-squared and t-tests for categorical and numerical variables, respectively. Trends in diagnosis, treatments, and outcomes were analyzed using ANOVA.

Results: 5438 patients were identified in the KID database with a primary diagnosis of CM-I (10.5 years, 55% F, CCI 0.21). CM-I primary diagnoses have increased over time (45 to 96 per 100,000, p< 0.001). CM-I patients had the following concurrent diagnoses: 23.8% syringomyelia/syringobulbia, 11.5% scoliosis, 5.9% hydrocephalus, 2.2% tethered cord syndrome, 0.5% torticollis, 0.3% Klippel Feil, 0.2% spina bifida. The average LOS for all CM-I patients was 4.02±7.78 days. Comorbidities included 1.8% anxiety, 2.4% depression, 5.5% functional digestive disorders. 83.4% of CM-I patients underwent surgical treatment, and the rate of surgical treatment for CM-I increased from 2003-2012 (66% to 72%, p< 0.001) though the rate of complications decreased over the same time (7% to 3%, p< 0.001) and mortality rates remained constant (p>0.05). The age of patients surgically treated for CM-I trended up over time (9.81-10.66 years, p=0.001). 70% of surgeries involved decompression only, which had increased neurologic complications as compared to surgeries that included fusions (p=0.039). The number of cranial decompressions performed for CM-I decreased from 2003-2012 (42.2%-30.5%, p< 0.001) while the rate of spinal decompression increased (73.1%-77.4%, p=0.019), although overall complication rates have been down-trending (6.4% to 2.9%, p< 0.001), fusion rates have increased over time (0.45% to 1.8%, p=0.026) and are associated with higher complication rates than decompression only (11.9% vs. 4.7%, p=0.007). Overall, 7.4% of patients experienced at least one peri-operative complication (nervous system, dysphagia, respiratory most common). Patients with concurrent hydrocephalus had increased nervous and respiratory systems, urinary, and respiratory complications (all p< 0.006) and syringomyelia increased the rate of respiratory complications (p=0.037).

Conclusions: CM-I malformation 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 experienced complication rates.