After suboccipital craniectomy plus C1–3 cervical laminectomy in 71 patients, with dural graft in 69, one death due to sleep apnea occurred 36 hrs post-op. Respiratory depression was the most common post-op complication (in 10 patients), usually within 5 days, mostly at night. Close respiratory monitoring is therefore recommended 1). Other risks of the procedure include: Cerebrospinal fluid fistula, herniation of cerebellar hemispheres, vascular injuries (to PICA…).
Systematic review of observational studies reveals higher reoperation rates after bony decompression alone, but clinical improvement was not higher after primary decompression with duraplasty. There are so far no high-quality studies that offer guidance in the choice of decompressive technique in adult CM1 patients 2).
Posterior fossa decompression for Chiari type 1 deformity is carried out to improve passage of cerebrospinal fluid (CSF) in patients with symptomatic Chiari I malformations (CM1), but the extent and means of decompression remains controversial. Dural opening with subsequent duraplasty may contribute to clinical outcome, but may also increase complication risk.
see Suboccipital pseudomeningocele after posterior fossa decompression for Chiari type 1 deformity.
A report describes the circumstances of a patient with a cauda equina syndrome due to the development of a lumbar spinal subdural hygroma with ventral displacement of the cauda equina shortly following posterior fossa decompression for Chiari type 1 deformity (CM-I). This unusual, but clinically significant, complication was successfully treated with percutaneous drainage of the extraarachnoid CSF collection. Although there are a few cases of intracranial subdural hygroma developing after surgery for CM-I, often attributed to a pinhole opening in the arachnoid, as far as the authors can determine, a spinal subdural hygroma associated with surgery for CM-I has not been recognized 3).