Résumé
The aim of this study was to propose new more reliable peripheral nerve transection model to overcome the defect of the traditional sciatic axotomy model by specifically transecting L5 spinal nerve just after emerging from the intervertebral foramen and confining analysis area to the L5 spinal segment. The adult male Sprague-Dawley rats, weighing 300~350 g at the time of surgery, were used for the experiments. Four different experimental groups were used. 1. Sciatic nerve transection (Sc-Tx) group: transect the sciatic nerve in the popliteal fossa where it divided into the common peroneal nerve and tibial nerve. 2. L5 spinal nerve transection (L5-Tx) group: L5 spinal nerve was specifically transected. 3. Suture (Su) group: L5 spinal nerve was transected and immediately sutured. 4. Control group: the same surgical procedure with L5 spinal nerve transection group was performed except for the excision of L5 spinal nerve. To distinguish L5 motoneurons from the other level ones, the animals were received the retrograde tracer, FluoroGold into the axotomized proximal nerve stump. Serial coronal frozen sections at 40 microm thick through the L4 to L6 spinal segment was performed and the resultant total number of sections was about 180. Approximate serial 50 sections (approximately 2 mm) could be considered as the L5 segment based on the number of the fluorescent signals (above 20). L5 spinal segment could be differentiated from L4 and L6 segment based on their morphological characteristics under Cresyl violet stain. In L5-Tx group, at 2 and 4 weeks post-transection, the number of L5 spinal motoneurons was reduced by 8%. Meanwhile, Sc-Tx and Su groups showed no statistically notable changes. In this study, the authors could propose more reliable peripheral nerve axotomy model than the conventional sciatic nerve axotomy model by specifically transecting L5 spinal nerve and confining the investigating area within the L5 spinal segment.
Sujets)
Adulte , Animaux , Humains , Mâle , Rats , Axotomie , Benzoxazines , Coupes minces congelées , Lésions des nerfs périphériques , Nerfs périphériques , Nerf fibulaire commun , Rat Sprague-Dawley , Nerf ischiatique , Nerfs spinaux , Matériaux de suture , Nerf tibial , ViolaRésumé
The aim of this study was to propose new more reliable peripheral nerve transection model to overcome the defect of the traditional sciatic axotomy model by specifically transecting L5 spinal nerve just after emerging from the intervertebral foramen and confining analysis area to the L5 spinal segment. The adult male Sprague-Dawley rats, weighing 300~350 g at the time of surgery, were used for the experiments. Four different experimental groups were used. 1. Sciatic nerve transection (Sc-Tx) group: transect the sciatic nerve in the popliteal fossa where it divided into the common peroneal nerve and tibial nerve. 2. L5 spinal nerve transection (L5-Tx) group: L5 spinal nerve was specifically transected. 3. Suture (Su) group: L5 spinal nerve was transected and immediately sutured. 4. Control group: the same surgical procedure with L5 spinal nerve transection group was performed except for the excision of L5 spinal nerve. To distinguish L5 motoneurons from the other level ones, the animals were received the retrograde tracer, FluoroGold into the axotomized proximal nerve stump. Serial coronal frozen sections at 40 microm thick through the L4 to L6 spinal segment was performed and the resultant total number of sections was about 180. Approximate serial 50 sections (approximately 2 mm) could be considered as the L5 segment based on the number of the fluorescent signals (above 20). L5 spinal segment could be differentiated from L4 and L6 segment based on their morphological characteristics under Cresyl violet stain. In L5-Tx group, at 2 and 4 weeks post-transection, the number of L5 spinal motoneurons was reduced by 8%. Meanwhile, Sc-Tx and Su groups showed no statistically notable changes. In this study, the authors could propose more reliable peripheral nerve axotomy model than the conventional sciatic nerve axotomy model by specifically transecting L5 spinal nerve and confining the investigating area within the L5 spinal segment.
Sujets)
Adulte , Animaux , Humains , Mâle , Rats , Axotomie , Benzoxazines , Coupes minces congelées , Lésions des nerfs périphériques , Nerfs périphériques , Nerf fibulaire commun , Rat Sprague-Dawley , Nerf ischiatique , Nerfs spinaux , Matériaux de suture , Nerf tibial , ViolaRésumé
OBJECTIVE: The 5th lumbar spinal nerve can be entrapped in the intraspinal zone, foraminal zone, and the extraforaminal zone simultaneously. The failure to recognize that the nerve root can be compressed in such manners may be the reason of a number of failures of surgical decompression. Here we describe a microsurgical method for the decompression of the triple entrapment of the L5 spinal nerve in 21 patients. METHODS: Clinical manifestations and surgical results of twenty-one patients treated surgically under the diagnosis of the triple entrapment of the L5 spinal nerve were reviewed retrospectively. All patients were treated by the posterior midline approach for the intraspinal entrapment and by the paraspinal approach for the foraminal and the extraforaminal entrapment. RESULTS: Pain relief was obtained in all patients immediately after surgery. The mean follow-up period after the surgery was 13 months, ranged from 6 to 24 months. The mean Numeric Rating Scale (pain score) improved from 8.9 before the surgery to 1.4 (p < 0.0001). The mean ODI scores improved from 76.2 before the surgery to 13.1 (p < 0.0001). Nineteen patients were satisfied with their result at the last follow-up examination. Neither complications related to the surgery, nor the spinal instability was detected. CONCLUSION: The triple entrapment of the 5th lumbar spinal nerve is an important pathologic entity to identify for the treatment of L5 radiculopathy. Combined medial and lateral approaches are safe, minimally invasive and it provide the complete decompression of triple entrapment of the L5 spinal nerve without causing secondary instability like after complete facetectomy.