A female Tibetan terrier aged five years and six months presented 23 months after portosystemic shunt attenuation due to generalised tonic–clonic epileptic seizure activity. Repeat MRI of the brain showed symmetrical T2-weighted hyperintense lesions affecting the cerebral grey matter bilaterally suggestive of cerebral atrophy and polioencephalomalacia. Cerebral atrophy and polioencephalomalacia could develop after successful attenuation of portosystemic shunt surgery.

Background: Canine spinal subarachnoid diverticulum has been studied since 1968 and a few advancements have been made with regard to the treatment of this disease. Several surgical techniques have been proposed which include durectomy, fenestration, and/or marsupilization with the latter two regarded as the more favorable surgical treatments. Aim: In this retrospective study, we evaluated the closure of the durotomy incision in the treatment of canine spinal subarachnoid diverticulum. Methods: We retrospectively evaluated eight dogs with clinical signs and magnetic resonance imaging findings consistent with spinal subarachnoid diverticulum located in the cervical and thoracolumbar area. This was to determine whether the fenestration with closure of durotomy was superior to the marsupialization technique. In all dogs, fenestration and removal of subarachnoid adherences alongside closure of the durotomy were carried out.  Results: Mild post-operative deterioration was observed in all dogs. Follow-up from 7 to 36 months indicated a satisfactory outcome. Conclusion: We conclude that the closure of durotomy has similar short-term and long-term outcomes compared to the previous reported studies. These results suggest that the closure of durotomy is a viable technique for spinal subarachnoid diverticulum.