EFFECTS OF EXPERIMENTAL NERVE ROOT COMPRESSION ON ARTERIAL BLOOD FLOW VELOCITY IN THE SEVENTH LUMBAR SPINAL GANGLION OF THE DOG: MEASUREMENT USING INTRAOPERATIVE DOPPLER ULTRASONOGRAPHY

Abstract

Intraoperative Doppler ultrasonography was used to measure the effects of four experimental nerve root compression treatments (central compression, central‐plus‐lateral compression, lateral compression, and compression release) on arterial blood flow velocities in the seventh lumbar spinal ganglion of three dogs. Graphed blood flow velocity changes (change = treatment value − pretreatment value) were below baseline during the first three compression treatments and above baseline following compression release. Mean blood flow velocity changes for both central‐plus‐lateral compression and lateral compression differed (p ≤ 0.05) from changes for central compression. Changes for central‐plus‐lateral compression did not differ (p > 0.05) from changes for lateral compression. Changes among the first three compression treatments differed (p ≤ 0.05) from changes for compression release. No histologic abnormalities were identified in compressed nerve tissues, compared to contralateral controls. These findings indicate that stenosis within the L7‐S1 intervertebral foramen may cause ischemia of the L7 spinal ganglion in dogs.