Mini-open exoscopic surgery for C1 restenosis 7 years after decompression of Chiari malformation type 1 with atlas assimilation.

Background: Chiari malformation type 1 (CM1) associated with atlas assimilation (AA) is rarely encountered in children without syringomyelia. Here, a 13-year-old child underwent an original foramen magnum decompression (FMD) for a CM1. Seven years after the index surgery, at age 20, the patient required secondary surgery to address recurrent C1 stenosis attributed to CM1/AA performed without a duraplasty.

Case description: A 13-year-old child originally presented with headaches and CM1 and AA, for which he underwent a FMD without duraplasty. Seven years later, at the age of 20, he developed recurrent C1 stenosis attributed to dorsal bony proliferation of the lamina of the atlas. Following a secondary mini-open exoscopic decompression without duraplasty, he became asymptomatic.

Conclusion: For patients with CM1 without syringomyelia, recurrent stenosis may be successfully managed with repeated mini-open exoscopic bony decompression.