Endoscope-assisted surgery of spinal intradural adhesions in the presence of cerebrospinal fluid flow obstruction.

Methods: Prospective cohort study. Objective: To investigate whether the adjunctive use of endoscopy of the subarachnoid space (arachnoscopy) can improve the success of microsurgery for spinal arachnoid adhesions.

Background: Intradural adhesions that obstruct pulsatile cerebrospinal fluid (CSF) flow are a typical spinal cause of syringomyelia. Phase-contrast magnetic resonance imaging (MRI) allows CSF flow obstructions to be reliably localized. The treatment of choice is the microsurgical removal of CSF flow obstructions caused by adhesions. Microsurgery, however, does not lend itself to assessments of further adhesions beyond the borders of the exposed area. In this study, we therefore investigated whether endoscopic assistance allows adhesions in the vicinity of the exposed area to be detected.

Methods: From 2006 to 2009, a single neurosurgeon performed 27 consecutive microsurgical procedures with endoscopic assistance in 25 patients with spinal arachnoid adhesions. A MurphyScope endoscope was used for this purpose. CSF flow was studied before and after surgery in all patients using phase-contrast MRI in the region of the craniocervical junction, the cervical spine, the thoracic spine, and the lumbar spine.

Results: In all 27 procedures, CSF flow obstructions were detected at the level identified by phase-contrast MRI. In 25 procedures, image quality was sufficient for an inspection of the adjacent subarachnoid space. In six cases, the surgeon detected further adhesions that obstructed CSF flow in the adjacent subarachnoid space not visualized with the microscope. In all cases, these adhesions were identified and removed during microsurgery.Postoperative MRI scans demonstrated free CSF flow in all patients and a decrease in syrinx size in six patients.

Conclusions: Arachnoscopy is a helpful adjunct to microsurgery and can be performed safely and easily. It allows the surgeon to detect further adhesions in the subarachnoid space, which would remain undetected by microscopy alone.