Effects of laminectomy on spinal cord blood flow

Abstract

The effect of a 1-segment (L-2) laminectomy on cat spinal cord blood flow (SCBF) was determined by the reference sample method using isotope-labeled microspheres. The SCBF was measured before laminectomy (control) and at 15 min post-laminectomy with the dura exposed, 1 h post-laminectomy with the laminectomy site cosed, 24 h post-laminectomy with the laminectomy site closed, and 24 h post-laminectomy with the dura exposed. With the laminectomy site open, SCBF was significantly depressed (22-45%) along the entire length of the spinal cord at 15 min post-laminectomy. At 1 h post-laminectomy (with the laminectomy site closed) SCBF approached control values, although areas with significantly lowered flow were still observed in all portions of the spinal cord. By 24 h post-laminectomy, SCBF had returned to pre-laminectomy levels. If within 1 h preceding the 24 h SCBF measurement the laminectomy site was re-opened, SCBF tended to fall at and caudad to the laminectomy site. Laminectomy apparently causes a significant decline in SCBF. At the present time the mechanism(s) for this laminectomy-induced depression of SCBF is unknown, although a temperature-induced vasoconstriction is suspected.