Information provided by Rossi House, DVM, Diplomate American College of Veterinary Internal Medicine (Neurology) at Nashville Veterinary Specialists
The answer to that question is still controversial and more work needs to be done to determine the true benefit of fenestration in association with decompressive surgery for disc extrusions.
Fenestration is the excision of the nucleus pulposus through a surgically created window in the annulus. Type I intervertebral disc disease is a common surgical disease of chondrodystrophic breeds and decompressive surgery consisting of a laminectomy is the treatment of choice. Fenestration alone has no merit as the sole surgical procedure in treating disc disease but it is often combined with decompressive surgery to try and reduce the recurrence rate.
The recurrence of clinical signs of IVDD after decompressive surgery is reported to be between 3 and 40%. Most studies looking at the effects of fenestration cite a recurrence rate of about 5%. Herniation recurrence at sites of fenestration has been shown to be decreased in several studies, but studies have failed to show a decrease in overall recurrence rates. I routinely fenestrate the site of the disc herniation and try to fenestrate as many disc spaces from T11/12 to L3/4 as possible in chondrodystrophic dogs.
Dogs that are not candidates for fenestration at the time of laminectomy are those with chronic disc herniations and most large breeds due to the potential destabilizing effect. Recurrence that necessitates reoperation can be devastating for owners leading to euthanasia and any opportunity to reduce that chance should be considered.