Introduction: Our objective was to compare clinical and radiological outcomes between craniotomy and the conventional craniectomy procedure for Chiari I malformation (CM-I) using a validated clinical outcome scale.
Methods: Patients aged 1-18 years of age who had undergone posterior fossa decompression surgery for CM-I at Sydney Children’s Hospital between 2011 and 2016 were recruited. Clinical outcomes were assessed using medical records and a questionnaire based on the Chicago Chiari Outcome Scale (CCOS). Radiological outcomes were assessed using pre/postoperative MRI scans to measure poster fossa volume (PFV) and ratio (PFVR), and syrinx size.
Results: 31 patients with previous CM-I decompressions were recruited: 7 had undergone the index craniotomy procedure, 24 the conventional craniectomy. There was no statistically significant difference between the clinical outcomes, including CCOS score, hospital stay, operative time and postoperative headaches/neck pain. However, a higher incidence of postoperative headaches (25% vs. 0) and one case of cerebellar ptosis in the craniectomy group was observed. From available MRIs, a similar rate of increase in PFV was found in craniotomy and craniectomy (1.07 vs.1.06). Syrinx improvement or resolution was seen in 70% of patients in the craniectomy group and 100% in the craniotomy group, with greater reduction of syrinx diameter and length observed in the craniotomy group.
Conclusions: Craniotomy is a safe and effective treatment for CM with comparable outcomes to conventional procedures, however future studies are required to determine if it is able to reduce the incidence of complications associated with craniectomy.
Patient Care: Our research shows that craniotomy is a viable option for patients requiring decompression for Chiari I, allowing the restoration of normal anatomy especially for individuals working in laborious occupations. Further more our study acts as a pilot for further research into whether postoperative headaches and other complications associated with the conventional craniectomy.
Learning Objectives: By the conclusion of this session, participants should be able to:
1. Describe complications associated with conventional craniectomy
2. Describe the various techniques of decompression eg. durotomy, duraplasty, and their advantages/disadvantages
3. Discuss the advanatages/disadvantages of craniectomy and craniotomy
4. Identify areas for further research on this topic