Abstract

Purpose: To ascertain changes in the microcirculation of nerve roots before and after retraction during lumbar interbody fusion surgery.We evaluate the blood flow at the site of the divergence from the dural tube through the use of a contact endoscope Subject & method: Subjects were 64 patients patients in the L4 nerve root in 3 patients and the L5 nerve root in 52 patients and S1 nerve root in 9 patients. Average age is 61.2yprocedure is TLIF-approach. Fusion cage is 14 mm diameter in 45 patients, 12 mm diameter in 19 patients retraction of nerve root is medial side.Software is our original Labo Library image analysis. Result: The results of root sign analysis for these 12 patients were fair, according to MacNab's criteria. Following nerve root retraction, the flow rate of erythrocytes through blood vessels decreased an average of 23.9%Intravascular erythrocyte agglutination (IEA), where erythrocytes flow in clumps due to changes in the charge state of erythrocytes, was seen in blood vessels larger than 100 µm in three patients after retraction.Using a 150x contact endoscope, we were able to observe blood cells in vessels as small as about 20µm in diameter in all 64 patients.according to MacNab's root sign result, decrease of central drift phenomenon is 68% in fair, 48% in good, 35% in excellent results.At the point of microrheology of Poiseuille's law, axial accumulation and axial drift phenomenon is to be analyzed by our original image guide software. Conclusion: A contact endoscope was used to observe the icrohemodynamics of nerve roots before and after retraction of the nerve root duringminimally invasive surgery, and a decrease in the flow rate of erythrocytes was observed.