Intra-, Epidural And Intracranial Pressure Changes During Interlaminar Endoscopy, With and Without Dural Tear

Area of Science:

• Neurosurgery
• Minimally Invasive Spine Surgery
• Spinal Physiology

Background:

• Endoscopic spine surgery may cause central nervous system complications like seizures.
• Increased intracranial pressure (ICP) is a suspected cause, potentially due to irrigation-induced spinal pressure.
• Monitoring pressure changes during interlaminar endoscopic lumbar discectomy (IELD) is crucial.

Purpose of the Study:

• To assess the impact of varying irrigation fluid settings during IELD on spinal and ICP.
• To evaluate these effects with and without dural tears.

Main Methods:

• Human cadavers were used to measure intradural, epidural, and ICP.
• Catheters and probes were placed at lumbar, thoracic, and cervical levels.
• IELD was performed at L3-4, with irrigation pressure varied using pump systems and gravity, before and after creating a dural tear.

Main Results:

• Intradural pressure correlated linearly with irrigation pressure across different systems and gravity.
• Similar pressure increases were observed at thoracic/cervical spine, epidural, and intracranial levels.
• Outflow occlusion and dural tears significantly exacerbated pressure elevations.

Conclusions:

• During IELD, pump pressure directly correlates with intra-/epidural and ICP.
• Without outflow occlusion, pressures remained within safe limits even at higher pump settings.
• Dural tears combined with occlusion and high pump pressures pose a risk for significant intradural and ICP increases.