Complication rates following Chiari malformation surgical management for Arnold-Chiari type I based on surgical variables: A national perspective.

INTRODUCTION

This study aimed to identify complication trends of Chiari Malformation Type 1 patients (CM-1) for certain procedures and concomitant diagnoses on a national level.

MATERIALS

The Kids' Inpatient Database was queried for diagnoses of operative CM-1 by International Classification of Disease-9 codes (348.4). Differences in preoperative demographics and perioperative complication rates between patient cohorts were assessed using Pearson's Chi-squared test and -test when necessary. Binary logistic regression was utilized to find significant factors associated with complication rate. Certain surgical procedures were analyzed for their relationship with postoperative outcomes.

RESULTS

Thirteen thousand eight hundred and twelve CM-1 patients were identified with 8.2% suffering from a complication. From 2003 to 2012, the rate of complications for CM-1 pts decreased significantly (9.6%-5.1%) along with surgical rate (33.3%-28.6%), despite the increase in CM-1 diagnosis (36.3%-42.3%; all < 0.05). CM-1 pts who had a complication were younger and had a lower invasiveness score; however, they had a larger Charlson Comorbidity Index than those who did not have a complication (all < 0.05). CM-1 pts who experienced complications had a concurrent diagnosis of syringomyelia (7.1%), and also scoliosis (3.2%; all < 0.05). CM-1 pts who did not have a complication had a greater rate of operation than those that had a complication (76.4% vs. 23.6% < 0.05). The most common complications were nervous system related (2.8%), anemia (2.4%), and acute respiratory distress (2.1%). CM-1 pts that underwent an instrumented fusion (3.4% vs. 2.1%) had a greater complication rate as well as compared to those who underwent a craniotomy (23.2% vs. 19.1%; all < 0.05). However, CM-1 pts that underwent a decompression had lower postoperative complications (21.3% vs. 28.9%; all < 0.05).

CONCLUSIONS

Chiari patients undergoing craniectomies as well as instrumented fusions are at a higher risk of postoperative complications especially when the instrumented fusions were performed on >4 levels.