Posterior Fossa Decompression Combined with Resection of the Cerebellomedullary Fissure Membrane and Expansile Duraplasty: A Radical and Rational Surgical Treatment for Arnold–Chiari Type I Malformation

Abstract

This study aims to introduce a new surgical procedure for the treatment of Arnold-Chiari type I malformation (ACM-1) and to compare its effectiveness with the techniques described in previous studies. We performed the following procedures: foramen magnum decompression combined with the removal of both the atlanto-occipital membrane, extended resection of the cerebellomedullary fissure arachnoid membrane, and artificial duraplasty to enlarge the membranic posterior fossa without resecting the cerebellar tonsils and syringosubarachnoid shunting. There were 21 ACM-1 patients: 12 cases had osteo-compression on the cerebellar hemisphere, 18 cases had thickened adhered fabric ring that stretched from arachnoid membrane to cerebellar hemisphere, and 15 cases with syringomyelia. The patients were followed up for 6 months to 3 years after the surgery. All patients showed a remarkable recovery of syringomyelia. There were no morbidity or death related to the surgery. Most of ACM-1 patients, the osteo- and membrane compression on cerebellar hemisphere and tonsil were observed during the operation. Therefore, decompression of foramen magnum and posterior craniocervical combined with the removal of cerebellomedullary fissure arachnoid membrane and placement of an artificial dural graft should be considered as a comprehensive option of minimally invasive surgery and rational and radical treatment of ACM-1. Our experience showed that, by using our procedure, shunting becomes no longer necessary in the treatment of ACM-1-associated syringomyelia.

Endoscopic Management of Arnold-Chiari Malformation Type I with or without Syringomyelia

“…Although the extent of the intradural procedure (minimal or more aggressive intradural manipulation) did not have a significant effect on the clinical outcome in the Lee et al series, 36 removal of the cerebellomedullary fissure arachnoid membrane and duraplasty was found to be workable in ACM-I. 32 Cerebellar tonsillectomy in addition to FMD and duraplasty has been advocated to provide long-term cure in ACM-I. 37 There is considerable debate as to whether a large versus a small craniectomy leads to better outcomes.…”

“…Although bony decompression with duraplasty was not practiced in our small series, duraplasty was found to be an effective and safe treatment option with a low complication rate. 31,32 Duraplasty was found to be superior to the non-duraplasty group in ACM-I with syrinx, although there was a slightly higher complication rate in the duraplasty group. 33 The duraplasty procedure was a more reliable choice in tonsillar herniation > 10 mm and in patients when symptom duration was < 36 months in ACM-I with syrinx.…”

Differentiated diagnostic and surgical algorithm for isolated and combined Chiari malformation Type I

“…The work of Liang et al, also proved the effectiveness of surgical correction with the inclusion of duroplasty in the case of Arnold-Chiari type I malformation (26). During surgery, compression of the tonsils, cerebellar hemisphere, and bone tissue was detected in most patients.…”