Motor and sensitive axonal regrowth after multiple intercosto-lumbar neurotizations in a sheep model

Abstract

Study design: Experimental animal study. Objective: To evaluate motor and sensitive axonal regrowth after multiple intercosto-lumbar neurotizations in a sheep model. Setting: France. Methods: Fifteen sheep were separated into three groups. Five sheep had multiple intercosto-lumbar neurotizations and a spinal cord lesion, five sheep were neurotized without any spinal cord lesion and five sheep had a spinal cord lesion without any neurotizations. Six months after the initial surgery, histological study of the neurotized roots was performed. Results: The length of the three rerouted intercostal nerves was sufficient in the 10 sheep to perform an intercosto-lumbar neurotization in good conditions. Eight sheep out of the 15 had postoperative complications responsible for the animal's death in five cases. Histological cross-sections of all the neurotized L2, L3 and L4 roots showed numerous myelinated regenerated axons. Dorsal root ganglions of neurotized roots showed both large and small neurons with normal nucleus and cytoplasm. The fluorescent retrograde labeling of 18 roots revealed labeled motor neurons in five cases. Conclusions: This study demonstrates the technical feasibility of intercosto-lumbar neurotizations in a big mammalian model. Intercostal nerve harvesting and rerouting was successfully performed in all the cases. Our histological results proved, in all the animals studied, the ability of motor and sensitive neurons to regenerate through the neurotization area. In the context of the future clinical application of strategies aimed at promoting axonal regeneration after severe spinal cord injury, the present data suggest that multiple intercosto-lumbar neurotization could be helpful to promote lower limb muscular strength recovery after spinal cord injuries.

Intercostal, ilioinguinal, and iliohypogastric nerve transfers for lower limb reinnervation after spinal cord injury: an anatomical feasibility and experimental study

“…Regarding the length of donor nerves and the fascicle count of both donor and recipient nerves, our findings were similar to those reported by various anatomical feasibility studies that investigated the internal topography of the nerves. 14,15,18,[31][32][33][34] Electrophysiological recording of motor potentials in all stimulated nerves was easily performed before and after the neurotization procedure. In all dogs, the ability of motor axons to regenerate through the neurotization area down to the motor endplates was proved.…”

Anatomical feasibility of transferring the obturator and genitofemoral nerves to repair lumbosacral plexus nerve root avulsion injuries

“…However, excision of the ulnar nerve severely impairs hand function and can involve considerable surgical trauma, which limits the application of this technique. The intercostal nerves (Zhang et al, ; Vialle et al, ) have been used to repair lumbar nerve injuries, with unsatisfactory outcomes. Because the free intercostal nerve is long, there is a lack of blood supply to the donor nerve.…”

“…In recent years, an increase in the incidence of high‐energy trauma has led to a rise in the incidence of lumbosacral plexus nerve root avulsion caused by pelvic fractures, sacroiliac joint dislocation, or sacral fractures, posing a challenge for treatment. (Vialle et al, ). Although lumbosacral plexus nerve root avulsion has been researched for more than 50 years, the majority of such injuries is treated conservatively with unsatisfactory results (Lang et al, ).…”

Effective reinnervation of the quadriceps femoris by spinal ventral root cross-anastomosis in rats

“…They also demonstrated the technical feasibility of intercosto-lumbar neurotizations in a big mammalian model and from human anatomy 22,23 . But there were unsatisfied results with regard to restoring the hindlimb movement after SCI 18,24,25 .…”