Nerve reconstruction in lumbosacral plexopathy. Case report and review of the literature

Surgical Interventions for Lumbosacral Plexus Injuries: A Systematic Review

Background:

Nerve reconstruction techniques for lumbosacral plexus (LSP) injuries vary. There are no clear treatment guidelines available, and summative evaluations of the literature discussing these surgeries are lacking. For these reasons, this investigation aimed to systematically review and consolidate all available literature discussing surgical interventions for LSP injuries and cohesively present patient-reported and objective postoperative outcomes.

Methods:

The authors conducted a systematic review using PubMed, Embase, Web of Science, ProQuest Dissertations and Theses Global (via Proquest.com), and ClinicalTrials.gov databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. After title and abstract screening, identified articles were read in full and selected for inclusion based on prespecified criteria.

Results:

Our literature search identified 8683 potential citations, and after duplicate removal, abstract screening, and full-text review, 62 studies remained meeting inclusion and exclusion criteria. Outcomes were extracted according to the location of injury and type of surgical repair. Injuries were classified into isolated femoral nerve injuries, isolated obturator nerve injuries, isolated sciatic nerve injuries, and multilevel LSP injuries. Surgical treatment was further classified into exploration with neurolysis, direct repair, nerve grafting, and nerve transfer surgery.

Conclusions:

Although results vary based on the location of the injury and the surgical technique used, nerve grafts and transfers demonstrated reasonable success in improving functional and pain outcomes. Overall, isolated femoral and obturator nerve injuries had the best outcomes reported with surgical treatment. Furthermore, incomplete sciatic nerve and multilevel LSP injuries had more reported surgical options and better outcomes than complete sciatic nerve injuries.

Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer

Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.

Contralateral Obturator to Femoral Nerve Branch Transfer for Multilevel Lumbosacral Plexus Avulsion Injury

We report successful restoration of quadriceps function following contralateral obturator to lateral branch of the femoral nerve transfer (with intervening autograft) in two patients with multilevel lumbosacral root avulsions, resulting in severe unilateral motor and sensory deficits. Three years postoperatively, patient 1 had regained Medical Research Council grade 3 knee extension with the ability to extend against 10 pounds of resistance. At 28 months postoperatively, patient 2 had regained Medical Research Council grade 2 knee extension. Treatment options for severe lumbosacral plexus injuries with multiple root avulsions are limited. This approach offers a new option for these devastating injuries.

Novel Uses of Nerve Transfers

Nerve transfer surgery involves using a working, functional nerve with an expendable or duplicated function as a donor to supply axons and restore function to an injured recipient nerve. Nerve transfers were originally popularized for the restoration of motor function in patients with peripheral nerve injuries. However, more recently, novel uses of nerve transfers have been described, including nerve transfers for sensory reinnervation, nerve transfers for spinal cord injury and stroke patients, supercharge end-to-side nerve transfers, and targeted muscle reinnervation for the prevention and treatment of postamputation neuroma pain. The uses for nerve transfers and the patient populations that can benefit from nerve transfer surgery continue to expand. Awareness about these novel uses of nerve transfers among the medical community is important in order to facilitate evaluation and treatment of these patients by peripheral nerve specialists. A lack of knowledge of these techniques continues to be a major barrier to more widespread implementation.

Anatomical feasibility of performing intercostal and ilioinguinal nerve to pelvic nerve transfer: a possible technique to restore lower urinary tract innervation

OBJECT

Nerve transfers are effective for restoring control to paralyzed somatic muscle groups and, recently, even to denervated detrusor muscle in a canine model. A pilot project was performed in cadavers to examine the feasibility of transferring somatic nerves to vesical branches of the pelvic nerve as a method for potentially restoring innervation to control the detrusor muscle in humans.

METHODS

Eleven cadavers were dissected bilaterally to expose intercostal, ilioinguinal, and iliohypogastric nerves, along with vesical branches of the pelvic nerve. Ease of access and ability to transfer the former 3 nerves to the pelvic vesical nerves were assessed, as were nerve cross-sectional areas.

RESULTS

The pelvic vesical nerves were accessed at the base of the bladder, inferior to the ureter and accompanied by inferior vesical vessels. The T-11 and T-12 intercostal nerves were too short for transfer to the pelvic vesical nerves without grafting. Ilioinguinal and iliohypogastric nerves (L-1 origin) were identified retroperitoneally and, with full dissection, were easily transferred to the pelvic vesical nerves intraabdominally. The mean cross-sectional area of the dominant pelvic vesical branch was 2.60 ± 0.169 mm(2); ilioinguinal and iliohypogastric branches at the suggested transection site were 2.38 ± 0.32 mm(2) (the means are expressed ± SEM).

CONCLUSIONS

Use of the ilioinguinal or iliohypogastric nerves for heterotopic transfer to pelvic vesical nerves is surgically feasible, based on anatomical location and cross-sectional areas.

Critical analysis of extra peritoneal antero-lateral approach for lumbar plexus

Lesions of lumbar plexus are uncommon and descriptions of surgical access are derived from vertebral spine approaches.

METHOD

The extraperitoneal anterolateral approach to the lumbar plexus was performed in six adult fresh cadavers. The difficulties on dissection were related.

RESULTS

An exposure of all distal elements of lumbar plexus was possible, but a cranial extension of the incision was needed to reach the iliohypogastric nerve in all cases. Ligation of vessels derived from common iliac artery was necessary for genitofemoral and obturator nerves exposure in two cases. The most proximal part of the lumbar roots could be identified only after dissection and clipping of most lumbar vessels.

CONCLUSION

The extraperitoneal anterolateral approach allows appropriate exposure of terminal nerves of lumbar plexus laterallly to psoas major muscle. Cranial extension of the cutaneous incision may be necessary for exposure of iliohypogastric nerve. Roots exposure increases the risk of vascular damage.

Feasibility of a femoral nerve motor branch for transfer to the pudendal nerve for restoring continence: a cadaveric study

OBJECT

Nerve transfers are an effective means of restoring control to paralyzed somatic muscle groups and, recently, even denervated detrusor muscle. The authors performed a cadaveric pilot project to examine the feasibility of restoring control to the urethral and anal sphincters using a femoral motor nerve branch to reinnervate the pudendal nerve through a perineal approach.

METHODS

Eleven cadavers were dissected bilaterally to expose the pudendal and femoral nerve branches. Pertinent landmarks and distances that could be used to locate these nerves were assessed and measured, as were nerve cross-sectional areas.

RESULTS

A long motor branch of the femoral nerve was followed into the distal vastus medialis muscle for a distance of 17.4 ± 0.8 cm, split off from the main femoral nerve trunk, and transferred medially and superiorly to the pudendal nerve in the Alcock canal, a distance of 13.7 ± 0.71 cm. This was performed via a perineal approach. The cross-sectional area of the pudendal nerve was 5.64 ± 0.49 mm(2), and the femoral nerve motor branch at the suggested transection site was 4.40 ± 0.41 mm(2).

CONCLUSIONS

The use of a femoral nerve motor branch to the vastus medialis muscle for heterotopic nerve transfer to the pudendal nerve is surgically feasible, based on anatomical location and cross-sectional areas.