The symposium is co-organised by The Ann Conroy Trust, in association with Aesculap Academia.
The Ann Conroy Trust is Registered Charity No: 1165808.
We provide Support, Education and Research for patients living with Chiari Malformation, Syringomyelia and associated conditions.
F17 Pitfalls in Chiari malformation type 1 treatment: possible causes of surgical failures.
Furlanetto M, Erbetta A, Saletti V, Chiapparini L, Babini M, Valentini L.
There are many discussions about surgical indications and techniques for Chiari I malformation (CM) but few doubt that, when there is an associated symptomatic or evolving syringomyelia, craniovertebral decompression with duraplasty is indicated. Failures of this first choice surgery are often complicated by progressive symptoms and slowly progressive neurological deterioration. The present study concerns 39 cases of revision Chiari surgery performed at the National Neurological Institute of Milan, between 1986 and 2018, 16 originally operated upon in our institution and 23 originally undergoing surgery elsewhere. In total they represent less than 10% of all cases (>350) initially operated upon at Besta in the same period.
Surgical treatment was based upon the “failure pathogenesis” subgroups, which we classified into: a) uncomplete/wrong bone decompression (6 cases); b) unperformed duraplasty (11); c) CSF leak with “compressive” collection (4); d) excessive bone opening with “CBL sinking” (1); e) syrinx fenestration and intracranial hypotension (1); f) arachnoiditis, spontaneous or after untreated CSF collection (3); g) craniovertebral joint instability (2); h) lack of resection of very low lying tonsils (4); i) inappropriate first surgery (4); j) unrecognized associated malformation (3).
One common finding was the high percentage (>50%) of patients requiring shunting/endoscopy for treatment of an associated hydrocephalus. Compared with our first surgery series, there were some cases of surgical morbidity and there was one case of post-operative mortality, caused by abdominal complications in an already highly compromised patient. Despite a good response of the syrinx to surgery, the neurological recovery was slow and uncomplete in the great majority of cases.
The results of “second look” operations can be good, if aimed at treating a recognized cause of failure. Often, permanent disturbance of CSF circulation is seen, caused by foramen magnum arachnoiditis and often needing treatment by endoscopy or shunting.