Adult Chiari I Malformations: An Analysis of Surgical Risk Factors and Complications Using an International Database

Background: Chiari I malformations are common in adults and a frequent procedure in neurosurgical practice. Despite several studies, there is no consensus about the indications or surgical technique for this common condition. Increasing emphasis on value-based care has emphasized reduction of readmissions and reoperations and is particularly relevant in Chiari, which has traditionally been associated with a high complication rate.

Objective: To provide a contemporary surgical profile of risk factors and complications for Chiari I malformations in adults.

Methods: The American College of Surgeons National Surgical Quality Improvement Program database was queried to determine 30-day outcomes after surgery for Chiari I malformations in adults between 2005 and 2016. Demographics, clinical risk factors, and postoperative events were analyzed, along with reoperation and readmission reasons.

Results: A total of 672 adult patients were identified in the cohort, with a female predominance (80%). The overall cohort readmission rate was 9.3%, and 6.8% of patients returned to the operating room. Obesity (45.7%) was predictive of both readmission and reoperation risk. Male sex and American Society of Anesthesiologists class were predictive for reoperations. The most common reason for reoperation was cerebrospinal fluid leak, which was responsible for nearly two thirds of reoperations and 4% of the cohort.

Conclusions: Surgery for Chiari in adults is common and carries a definitive risk profile, including rates of readmission and reoperation higher than other common neurosurgical procedures. This cohort provides a representative sample of contemporary neurosurgical outcomes in surgery for Chiari I malformations.