EFFECTS OF EXPERIMENTAL NERVE ROOT COMPRESSION ON ARTERIAL BLOOD-FLOWVELOCITY IN THE 7TH LUMBAR SPINAL GANGLION OF THE DOG - MEASUREMENT USING INTRAOPERATIVE DOPPLER ULTRASONOGRAPHY

Intraoperative Doppler ultrasonography was used to measure the effects of four experimental nerve root compression treatments (central compr ession, central-plus-lateral compression, lateral compression, and com pression release) on arterial blood flow velocities in the seventh lum bar spinal ganglion of three dogs, Graphed blood flow velocity changes (change = treatment value - pretreatment value) were below baseline d uring the first three compression treatments and above baseline follow ing compression release. Mean blood flow velocity changes for both cen tral-plus-lateral compression and lateral compression differed (p less than or equal to 0.05) from changes for central compression. Changes for central-plus-lateral compression did not differ (p > 0.05) from ch anges for lateral compression. Changes among the first three compressi on treatments differed (p less than or equal to 0.05) from changes for compression release. No histologic abnormalities were identified in c ompressed nerve tissues, compared to contralateral controls. These fin dings indicate that stenosis within the L7-S1 intervertebral foramen m ay cause ischemia of the L7 spinal ganglion in dogs.