Winner of the DePuy Synthes Resident Craniofacial Award, Ryan Patrick Morton presented his research, Timing of Cranioplasty: A 10-year Single-center Analysis of 754 Patients, during the 2016 American Association of Neurological Surgeons (AANS) Annual Scientific Meeting.
Despite technical simplicity, cranioplasty procedures harbour high reported morbidity rates. This represents the largest study to date on complications after cranioplasty, focusing specifically on the ideal timing of the operation.
The authors retrospectively reviewed all cranioplasties performed at Harborview Medical Center (Seattle, USA) over the past 10.75 years: over 750 procedures. Sixty per cent were male with an average follow up of 533 days. Thirty-day mortality was 0.26% (n=2, both due to post-operative epidural haematoma). Morbidity was 22.7%, including infection necessitating explanation of the flap (6.6%), post-operative hydrocephalus requiring a shunt (5.7%), resorption of flap (4.5%), seizure (3.4%), post-operative haematoma requiring evacuation (0.9%) and other (1.6%).
When evaluating complication rates against the timing of the cranioplasty, the authors found infection was significantly higher when the cranioplasty was performed 14 days from the original decompression. Hydrocephalus was statistically less common in patients whose cranioplasty was performed after 90 days; however, new onset seizure occurred only in patients who received their cranioplasty at less than 90 days. The resorption rate was lowest when the cranioplasty was performed within 15–30 days from the original decompression and was also statistically influenced by patient age. The hazard ratio for resorption decreased by 33% per increase of 10 years of age.
While the ideal timing for cranioplasty remains controversial, the data suggests that performing the procedure between two and four weeks helps minimize infection, seizure and resorption. Waiting less than 90 days minimises hydrocephalus but also significantly increases risk of seizure.