Peripheral Nerve Injury Repair Using Synthetic Conduits or Processed Nerve Allografts

POLICY NUMBER

A.7.01.177

DESCRIPTION

Peripheral nerve injuries are common traumatic events for which the conventional treatment is the microsurgical repair for gaps <5 mm in length. Autologous grafting is used for repairing nerve gaps of greater length. Because autologous grafts must be harvested from the patient, there is a risk of donor site complications, and the overall success rate of autografting may be limited. Therapies such as processed nerve allografts and synthetic nerve conduits are being investigated to provide improved treatment alternatives.

Peripheral Nerve Injury

Injuries to the peripheral nerves are common and occur in approximately 2.5% of trauma patients in the United States, with an average incidence of over 550,000 annually. Based on hospital ICD-9 coding, the most commonly injured peripheral nerves reported by hospitals were the upper extremity digital nerves, ulnar nerve, radial nerve, and the brachial plexus. Functional regeneration of injured nerves requires peripheral nerve surgery to allow axon regrowth and remyelination.

Conventional Treatment

Direct surgical repair (e.g. end-to-end coaptation or neurorrhaphy) is the standard of care for transected nerves when the gap distance permits tensionless suturing. However, when the size of the peripheral nerve gap precludes tensionless direct surgical repair, the standard of care is nerve autograft. Alternatives to autografting are being investigated to bridge nerve discontinuities to avoid complications from harvesting (e.g., pain or numbness) at the donor site as well as issues such as nerve fascicle mismatch and damage to the autograft from tissue handling.

Alternative Treatments

Allogenic nerve grafts are derived from human donors and are generally used to bridge gaps resulting from peripheral nerve injuries that are >5 mm. Allogenic grafts are preferred for their potential to minimize donor site morbidity, as they eliminate the need for autografts. Allogenic grafts also address the challenge of obtaining a sufficient graft length as they are available in multiple lengths and diameters; this is particularly relevant in cases where the injury site is extensive. Before transplantation, allografts undergo processing to ensure immunological compatibility and reduce the risk of rejection, allowing for successful integration into the recipient's nervous system.

Synthetic nerve conduits are hollow tubular structures designed to bridge nerve gaps caused by injury or trauma, providing a supportive environment for the regrowth of damaged nerve fibers. They are available in various biocompatible materials, lengths, and diameters and are designed to degrade over time. The conduits serve as guidance channels for regenerating nerves, facilitating directional growth, and preventing scar tissue formation. Conduits are generally used for nerve gap repairs of <5 mm.

The U.S. Food and Drug Administration (FDA) regulates human cells and tissues intended for implantation, transplantation, or infusion through the Center for Biologics Evaluation and Research, under Code of Federal Regulation, title 21, parts 1270 and 1271. Avance Nerve Grafts subject to these regulations.

A number of processed nerve allografts and synthetic conduits have been approved through the FDA 510k process for individuals undergoing peripheral nerve repair (See the table below.). This list includes products for which this reference medical policy did not find any published, peer-reviewed research that satisfied the PICO (Population, Intervention, Comparison, Outcome) criteria.

FDA 510K Approved Processed Nerve Allografts and Synthetic Conduits for Peripheral Nerve Repair

Related medical policies –

• Bioengineered Skin and Soft Tissue Substitutes

• Nerve Graft with Radical Prostatectomy

POLICY

The use of processed nerve allografts for the repair and closure of peripheral nerve gaps up to 70 mm is considered medically necessary when direct primary repair is not feasible (see Policy Guidelines).

The use of synthetic nerve conduits for the repair and closure of peripheral nerve gaps is considered medically necessary in the following scenarios (see Policy Guidelines):

• Repair of digital nerve injuries with gaps <15 mm; OR

• Repair of digital nerve injuries with gaps 15-25 mm, where allograft nerve is not available; OR

• Repair of major nerves with small gaps not exceeding 6 mm, where allograft nerve is not available; OR

• In the context of conduit-assisted repair as a technique for tension-relief at the peripheral nerve repair site or major nerve with a gap not exceeding 6 mm.

All other uses of processed nerve allografts and synthetic nerve conduits for individuals with peripheral nerve gaps are considered investigational.

POLICY EXCEPTIONS

Federal Employee Program (FEP) may dictate that all FDA-approved devices, drugs or biologics may not be considered investigational and thus these devices may be assessed only on the basis of their medical necessity.

POLICY GUIDELINES

The coverage guidelines outlined in the Medical Policy Manual should not be used in lieu of the Member's specific benefit plan language.

Feasibility of direct repair may be limited in individuals with large nerve gaps, segmental nerve loss, or chronic and complex injuries. While there are mixed data regarding comparability of autograft versus allograft repair, allograft repair offers the benefit of avoiding donor site morbidity. This is of particular importance where the primary consideration is the management or prevention of neuropathic pain. For larger sensory, motor, or mixed nerves, autograft repair should be considered the standard intervention except if there is insufficient donor material for autografting. The maximum available allograft length is 70 mm, and there is no data to support the technique of connecting allografts end-to-end.

For digital nerve injuries with gaps 15-25 mm, conduit repair yields acceptable sensory outcomes but is inferior to allograft repair. Therefore, conduit repair should only be used in such scenarios when allograft nerve is not immediately available (e.g. in the context of urgent traumatic injuries).

Nerve wraps are bioresorbable surgical implants designed to protect and support peripheral nerve healing following end-to-end repair with no gap. These devices provide a physical barrier that purports to reduce scar formation, reduce mechanical irritation, and promote a favorable environment for nerve regeneration. These materials are addressed in the Bioengineered Skin and Soft Tissue Substitutes medical policy.

Contraindications

Both allograft and conduit repair are contraindicated in a surgical field with active infection. Synthetic conduits are contraindicated for individuals with a history of an allergic reaction or sensitivity to any component of the synthetic conduit (e.g., bovine, porcine, or chondroitin materials).

Medically Necessary is defined as those services, treatments, procedures, equipment, drugs, devices, items or supplies furnished by a covered Provider that are required to identify or treat a Member's illness, injury or Mental Health Disorders, and which Company determines are covered under this Benefit Plan based on the criteria as follows in A through D:

A.  consistent with the symptoms or diagnosis and treatment of the Member's condition, illness, or injury; and

B.  appropriate with regard to standards of good medical practice; and

C.  not solely for the convenience of the Member, his or her Provider; and

D.  the most appropriate supply or level of care which can safely be provided to Member. When applied to the care of an Inpatient, it further means that services for the Member's medical symptoms or conditions require that the services cannot be safely provided to the Member as an Outpatient.

For the definition of medical necessity, “standards of good medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. BCBSMS makes no payment for services, treatments, procedures, equipment, drugs, devices, items or supplies which are not documented to be Medically Necessary. The fact that a Physician or other Provider has prescribed, ordered, recommended, or approved a service or supply does not in itself, make it Medically Necessary.

Investigative is defined as the use of any treatment procedure, facility, equipment, drug, device, or supply not yet recognized as a generally accepted standard of good medical practice for the treatment of the condition being treated and; therefore, is not considered medically necessary. For the definition of Investigative, “generally accepted standards of medical practice” means standards that are based on credible scientific evidence published in peer-reviewed medical literature generally recognized by the relevant medical community, and physician specialty society recommendations, and the views of medical practitioners practicing in relevant clinical areas and any other relevant factors. In order for equipment, devices, drugs or supplies [i.e, technologies], to be considered not investigative, the technology must have final approval from the appropriate governmental bodies, and scientific evidence must permit conclusions concerning the effect of the technology on health outcomes, and the technology must improve the net health outcome, and the technology must be as beneficial as any established alternative and the improvement must be attainable outside the testing/investigational setting.

POLICY HISTORY

05/01/2024: New policy added. Approved by the Medical Policy Advisory Committee.

05/15/2025: Policy description updated regarding products. Policy statement revised to state that the use of processed nerve allografts for the repair and closure of peripheral nerve gaps up to 70 mm is considered medically necessary when direct primary repair is not feasible. It previously stated: The use of processed nerve allograft for the repair and closure of peripheral nerve gaps is considered investigational. Added statement that the use of synthetic nerve conduits for the repair and closure of peripheral nerve gaps is considered medically necessary when the listed criteria are met. Revised policy statement to state that all other uses of processed nerve allografts and synthetic nerve conduits for individuals with peripheral nerve gaps are considered investigational. Policy Guidelines updated regarding feasibility of direct repair, digital nerve injuries, nerve wraps, and contraindications. Added medically necessary definition. Code Reference section updated to change the coding table from Investigational to Medically Necessary and remove CPT code 64999.

SOURCE(S)

Blue Cross Blue Shield Association policy # 7.01.177

CODE REFERENCE

This may not be a comprehensive list of procedure codes applicable to this policy.

The code(s) listed below are ONLY medically necessary if the procedure is performed according to the "Policy" section of this document.

Medically Necessary Codes

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