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.
F32 Histological analysis of arachnoid features in Chiari I malformation.
Klekamp J, Heidary M.
Although foramen magnum decompression is accepted as the treatment of choice for Chiari I malformation, the surgical technique is controversial. Do we need to open and dissect the arachnoid? Do we need duraplasties? This paper focusses on histological features of the arachnoid in these patients.
162 consecutive arachnoid samples, taken routinely during foramen magnum procedures over a period of 10 years, were analysed, measuring thickness, cellularity and the amount of fibrosis. These measurements and evaluations were performed blinded for any clinical data or intra-operative findings. A classification into three grades of arachnoid features was created. These histological grades were compared with intraoperative evaluations of arachnoid changes and their relevance for pre-operative symptoms and post-operative results was analysed.
Arachnoid features were found to be quite variable in terms of thickness, cellularity and the amount of fibrosis, each following a normal distribution. The histological grades correlated significantly with intraoperative evaluations of the arachnoid, as noted by the surgeon after dural opening. Highly significant correlations were found between histological grades and the severity of pre-operative gait problems, motor weakness and sensory disturbances. On the other hand, intraoperative evaluations of arachnoid changes by the surgeon showed significant correlations with the presence of syringomyelia, the postoperative clinical result after 3 months and rates for progression-free survival in the long-term.
Although this study cannot prove a causal relationship between arachnoid features and clinical symptoms or postoperative results, it clearly shows that the arachnoid should not be considered irrelevant in patients with Chiari I malformation.