Interventional procedure consultation document

Phrenic nerve transfer in brachial plexus injury

Repairing damaged nerves after brachial plexus injury by transferring a nerve from the diaphragm

The brachial plexus is the bundle of nerves running from the neck to the armpit which supplies movement and feeling to the arm and hand. Damage to the brachial plexus can cause paralysis of the arm or hand, and can be associated with severe pain.

This procedure uses the phrenic nerve (the nerve to the diaphragm – a muscle in the bottom of the ribcage that is used for breathing) to repair damaged nerves in the brachial plexus, with the aim of restoring some useful function to the arm.

The National Institute for Health and Care Excellence (NICE) is examining phrenic nerve transfer in brachial plexus injury and will publish guidance on its safety and efficacy to the NHS in England, Wales, Scotland and Northern Ireland. NICE’s Interventional Procedures Advisory Committee has considered the available evidence and the views of specialist advisers, who are consultants with knowledge of the procedure. The Advisory Committee has made provisional recommendations about phrenic nerve transfer in brachial plexus injury.

This document summarises the procedure and sets out the provisional recommendations made by the Advisory Committee. It has been prepared for public consultation. The Advisory Committee particularly welcomes:

• comments on the provisional recommendations
• the identification of factual inaccuracies
• additional relevant evidence, with bibliographic references where possible.

Note that this document is not NICE’s formal guidance on this procedure. The recommendations are provisional and may change after consultation.

The process that NICE will follow after the consultation period ends is as follows.

• The Advisory Committee will meet again to consider the original evidence and its provisional recommendations in the light of the comments received during consultation.
• The Advisory Committee will then prepare draft guidance which will be the basis for NICE’s guidance on the use of the procedure in the NHS in England, Wales, Scotland and Northern Ireland.

For further details, see the Interventional Procedures Programme manual, which is available from the NICE website.

Through its guidance NICE is committed to promoting race and disability equality, equality between men and women, and to eliminating all forms of discrimination. One of the ways we do this is by trying to involve as wide a range of people and interest groups as possible in the development of our interventional procedures guidance. In particular, we aim to encourage people and organisations from groups who might not normally comment on our guidance to do so.

In order to help us promote equality through our guidance, we should be grateful if you would consider the following question:

Are there any issues that require special attention in light of NICE’s duties to have due regard to the need to eliminate unlawful discrimination, advance equality of opportunity, and foster good relations between people with a characteristic protected by the equalities legislation and others?

Please note that NICE reserves the right to summarise and edit comments received during consultations or not to publish them at all where in the reasonable opinion of NICE, the comments are voluminous, publication would be unlawful or publication would otherwise be inappropriate.

Closing date for comments: 16 August 2013

Target date for publication of guidance: 27 November 2013

1                      Provisional recommendations

1.1                  The limited quantity of evidence on the efficacy of phrenic nerve transfer in brachial plexus injury shows useful recovery of limb function in some patients, but there is very little information about long-term functional and quality of life outcomes. Evidence on safety shows some impairment of respiratory function. Patients with brachial plexus injuries are often very disabled and other treatment options may be limited. Therefore, this procedure may be used with normal arrangements for clinical governance, consent and audit.

1.2                  During the consent process patients should be informed, in particular, that the procedure may not restore useful function in the arm and that it may compromise respiratory function.

1.3                  Patient selection and treatment should only be carried out in units that specialise in the management of complex brachial plexus injuries and offer a full range of treatment options.

2                      Indications and current treatments

2.1                  Brachial plexus injuries are typically caused by traction of the arm at birth and in road traffic accidents. They result in loss of sensation and movement in all or part of the arm and can be associated with severe pain. The exact symptoms depend on the location of the injury and its severity.

2.2                  Brachial plexus injuries in which the nerves are injured but still intact are usually managed by conservative care, including physiotherapy. If the plexus has been disrupted then surgical repair is considered. This may be possible by direct suture, or it may involve the use of nerve grafts if the nerve ends are separated. If neither of these is possible, for example in nerve root avulsion, nerve transfer (neurotisation) can be done, in which a healthy nerve to a different muscle is joined to a damaged nerve, to re-innervate the affected arm muscle. A variety of nerves may be used for this kind of procedure, including intercostal nerves, the spinal accessory nerve, the phrenic nerve and the motor branches of the cervical plexus. Sometimes, free muscle or tendon transfer is done in combination with nerve transfer to re-innervate the forearm muscles.

3                      The procedure

3.1                  The procedure is performed under general anaesthesia by a supraclavicular approach. The brachial plexus is explored and the root avulsion confirmed. The phrenic nerve is identified in the neck on the surface of the scalenus anterior muscle, or in the chest thorascopically to provide a longer segment for grafting. Phrenic nerve function is confirmed by neurophysiology. The nerve is divided, transferred and joined to the distal segment of the selected damaged nerve either directly or via an interposition graft if necessary. The aim of the procedure is to re-innervate the target muscles and improve upper limb function.

3.2                  Postoperatively, a head and shoulder spica may be applied for several weeks to avoid tension on the nerve transfer.  Specialist rehabilitation is provided to maximise the recovery of useful arm function.

3.3                  Phrenic nerve transfer may be combined with other donor nerve transfers at the same time or in stages.

4                      Efficacy

This section describes efficacy outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview

4.1                  A quasi-randomised study comparing phrenic nerve transfer (PNT; n=17) against intercostal nerve transfer (n=19) to the musculocutaneous nerve in 36 patients reported that motor recovery of biceps occurred significantly later in the PNT group (mean 262 days) than in the intercostal nerve transfer group (mean 195 days; p=0.03). Biceps muscle motor recovery to Medical Research Council (MRC) grade 3 (able to overcome gravity) or greater strength was reported in 29% (5/17) of patients in the PNT group and 53% (10/19) of patients in the intercostal nerve transfer group at 1-year follow-up. In the PNT group 23% (4/17) of patients had no recovery, but all patients in the intercostal nerve transfer group regained some muscle motor function, and after rehabilitation could separate breathing from biceps function.

4.2                  A case series of 40 patients treated by PNT to the anterior division of the upper trunk of the brachial plexus to restore elbow flexion reported that the biceps muscle strength recovered to MRC grade 3 or greater in 83% (33/40) of patients at an average follow-up of 28.2 months. Recovery to MRC grade 3 or greater strength occurred in 91% (29/32) of patients aged under 40 years, and in 50% (4/8) of patients aged 40 years and over. For patients who had the procedure more than 1 year after the injury, the recovery rate was 25% (1/4 patients).

4.3                  A retrospective case series of 180 patients treated by PNT to the musculocutaneous nerve followed up 65 patients for more than 2 years. The study reported that 85% (55/65) of patients regained biceps muscle power to MRC grade 3 or greater strength. The average time taken for restoration of muscle strength to MRC grade 3 was 9.5 months. Longer delays in treatment were associated with lower levels of recovery. Patients who had a nerve graft had similar results to patients who had a direct nerve transfer. Poor results were seen in patients with severe crush injuries and associated fractures in the shoulder region.

4.4                  The specialist advisers listed key efficacy outcomes as restoration of muscle function or joint movement/elbow flexion, shoulder stability, control of re-innervated muscles and functional scores such as DASH (Disabilities of the Arm Shoulder and Hand) and QALY(quality adjusted life year) measures.

5                      Safety

This section describes safety outcomes from the published literature that the Committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the overview

5.1                  A retrospective comparative study of 42 patients comparing PNT (n=19) against PNT with multiple intercostal nerve transfer (PNT+MIT; n=23) reported that a certain degree of hemidiaphragm elevation (a mean of 1–1.5 intercostal spaces) was observed in 90% (38/42) of patients at a mean follow-up of 10 years. Diaphragmatic excursion was reduced by a mean of 0.5–1 intercostal spaces in both the groups after the procedures. Hemidiaphragm elevation and movement reduction did not worsen as the number of intercostal nerves used increased from 2–4 in the PNT+MIT group, or if both procedures were done at the same stage or performed at an interval of 1–2 months.

5.2                  A case series of 19 patients treated by PNT+MIT reported persistent ipsilateral diaphragmatic paralysis in all patients for up to 36 months of the study (p<0.01).

5.3                  The quasi-randomised study of 36 patients comparing PNT (n=17)  against intercostal nerve transfer (n=19) reported that pulmonary function (forced vital capacity, forced expiratory volume in 1 second, vital capacity and tidal volume) was significantly lower in the PNT group than in the intercostal nerve transfer group throughout 1 year of follow-up. Body position had a significant effect on forced vital capacity in the PNT group but no effect in the intercostal nerve transfer group.

5.4                  The retrospective case series of 65 patients reported that pulmonary function tests in 19 patients (including forced vital capacity, total lung capacity, functional residual capacity, vital capacity and maximum ventilation volume) showed decreased pulmonary function within 1 year of PNT surgery, improving to normal values by 2 years.

5.5                  The case series of 19 patients who had PNT+MIT reported mild dyspnoea on exertion in 42% (8/19) of patients at 6 months follow-up (p<0.05), which resolved by 1-year follow-up.

5.6                  The specialist advisers listed theoretical adverse events as chest wall deformity, herniation, basal atelectasis/collapse, poor voluntary control of muscles innervated by the transfer and failure to re-innervate target muscles due to proximal injury to the phrenic nerve.

_{Personal data will not be posted on the NICE website. In accordance with the Data Protection Act names will be anonymised, other than in circumstances where explicit permission has been given.}

 _{It is the responsibility of consultees to accurately cite academic work in order that they can be validated.}

Bruce Campbell

Chairman, Interventional Procedures Advisory Committee

July 2013