ABSTRACT
This study investigated the effect of local administration of nerve growth factor-7S (NGF-7S) on the axonal regrowth of mixed peripheral nerves through inside-out vein grafts. Sixty male Wistar rats were randomized into two groups (n = 30). A defect 12 mm long in the right sciatic nerve was created and repaired with an inside-out vein graft from the right jugular vein. NGF-7S (group A) or phosphate-buffered saline (group B; control) was locally administered daily during the first 3 weeks. Walking-track analysis and electrophysiological and histological-morphometric studies were carried out 4, 6, 8, 10, and 12 weeks postoperatively (subgroups a, b, c, d, and e, respectively, n = 6 each). Data analysis showed that 1) the recovery of motor function, as measured by walk pattern analysis and evoked muscle action potential, and 2) the orientation, number, myelin thickness, and diameter of myelinated fibers were better in the NGF-7S than in the control group. These findings present strong evidence of the beneficial effect of NGF-7S on peripheral nerve regeneration through inside-out vein grafts.
Subject(s)
Nerve Growth Factor/pharmacology , Nerve Regeneration/drug effects , Sciatic Nerve/drug effects , Veins/transplantation , Analysis of Variance , Animals , Biopsy, Needle , Disease Models, Animal , Electrophysiology , Immunohistochemistry , Male , Microscopy , Nerve Regeneration/physiology , Neural Conduction , Probability , Random Allocation , Rats , Rats, Wistar , Recovery of Function , Reference Values , Sciatic Nerve/pathology , Sciatic Nerve/surgery , Transplantation, AutologousABSTRACT
The aim of this study was to develop a standardized effective thrombogenic arterial anastomosis model, as usually encountered in clinical practice, and to offer a detailed evaluation of the antithrombotic effect of thrombin's direct inhibitors, antithrombin III and hirudin, as locally applied. Wistar rats were divided into four groups of 12 animals each. The carotid artery sustained a standardized crush-avulsion-type injury (groups B-D). A segment of the afflicted area was removed and replaced by a microvenous graft. Group A had no crush-avulsion injury inflicted; a microvenous graft replaced a simple resection from the center of the carotid artery. During microvascular anastomoses, normal saline (groups A and B), recombinant hirudin (group C), or antithrombin III (group D) were locally applied. Bleeding times were recorded, and patency tests were performed 20 min, 48 h, and 1 week after blood flow reestablishment. All grafts were harvested and examined histologically. Patency tests, 1 week postrevascularization, demonstrated that this experimental crush-avulsion injury model ensured low patency in group B (25%), whereas group A, which had no injury inflicted, achieved a 100% patency rate. The local application of hirudin and antithrombin III significantly increased bleeding times as well as the patency rate (92% and 75%, respectively) compared to group B. These findings indicate the efficiency of the experimental model and the potential use of thrombin's direct inhibitors in microvascular surgery.
