Extradural foramen magnum decompression with multiple superficial dural incisions for Chiari I malformation: a multicenter series of 91 pediatric patients.

PURPOSE: To assess surgical outcome of pediatric patients undergoing foramen magnum decompression (FMD) with multiple superficial dural incisions (MSDI) in Chiari I malformation (CM I), with or without syringomyelia.

METHODS

A retrospective review of 91 pediatric patients who underwent FMD with MSDI technique between 2010 and 2024 at three tertiary neurosurgical centers.

RESULTS

Median age at surgery was 10 years (range 1-18). 57% were female. Preoperative symptoms included headaches/neck pain (55%), neurological deficits (44%), dysphagia (13%), snoring (18%), and cranial nerve involvement (12%). Syringomyelia was present in 48 patients (53%). All patients underwent C1 laminectomy in addition to FMD, and 10% also C2 laminectomy. Short term complications occurred in 7 cases (8%). All were wound problems which did not require reoperation. Median follow-up time was 3 years (range 1-13). Postoperatively: Headaches improved in 90% (45/50) Syrinx size reduced or was stable in 87% (42/48) Syrinx size progression was seen in 13% (6/48) Four patients (4%) developed a new syrinx following the procedure Neurological deficits improved or stabilized in 87% (34/40) No surgical site infection, CSF leak, hydrocephalus, or new permanent neurological deficits were observed. The reoperation rate was 10%.

CONCLUSION

Our results indicate that extradural FMD with MSDI can be considered a safe and effective treatment of CM I in pediatric patients, even in the presence of syringomyelia. No correlations between age, gender, scoliosis, tonsil herniation level, follow-up length, syrinx size and level, CXA, pB-C2, surgeon, and syrinx changes after surgery were found. Age showed no significant correlation with postoperative headache improvement.