Treatment for thoracic outlet syndrome.

BACKGROUND

Thoracic outlet syndrome (TOS) is one of the most controversial diagnoses in clinical medicine. Despite many reports of operative and non-operative interventions, rigorous scientific investigation of this syndrome leading to evidence-based management is lacking. This is the first update of a review first published in 2010.

OBJECTIVES

To evaluate the beneficial and adverse effects of the available operative and non-operative interventions for the treatment of TOS a minimum of six months after the intervention.

SEARCH METHODS

On 23 June 2014 we searched the Cochrane Neuromuscular Disease Group Trials Specialized Register, CENTRAL, The Database of Abstracts of Reviews of Effects (DARE), MEDLINE, EMBASE, CINAHL Plus and AMED. We also searched reference lists of the identified trials.

SELECTION CRITERIA

We selected randomized or quasi-randomized studies involving participants with the diagnosis of TOS of any type (neurogenic, vascular, and 'disputed'), without limitations as to language of publication.We accepted studies that examined any intervention aimed at treating TOS.The primary outcome measure was change in pain rating, measured on a validated visual analog or similar scale at least six months after the intervention.The secondary outcomes were change in muscle strength, disability, experiences of paresthesias (numbness and tingling sensations), and adverse effects of the interventions.

DATA COLLECTION AND ANALYSIS

Three authors independently selected the trials to be included and extracted data. Authors rated included studies for risk of bias, according to the methods recommended in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

This review was complicated by a lack of generally accepted criteria for the diagnosis of TOS and had to rely exclusively on the diagnosis of TOS by the investigators in the reviewed studies. We identified one study comparing natural progression with an active intervention. We found three randomized controlled trials (RCTs), but only two of them had a follow-up of six months or more, which was the minimum required follow-up for inclusion in the review. The first trial that met our requirements involved 55 participants with the 'disputed type' of TOS and compared transaxillary first rib resection (TFRR) with supraclavicular neuroplasty of the brachial plexus (SNBP). The trial had a high risk of bias. TFRR decreased pain more than SNBP. There were no adverse effects in either group. The second trial that met these requirements analyzed 37 people with TOS of any type, comparing treatment with a botulinum toxin (BTX) injection into the scalene muscles with a saline placebo injection. This trial had a low risk of bias. There was no significant effect of treatment with the BTX injection over placebo in terms of pain relief or improvements in disability, but it did significantly improve paresthesias at six months' follow-up. There were no adverse events of the BTX treatment above saline injection.

AUTHORS' CONCLUSIONS: This review was complicated by a lack of generally accepted diagnostic criteria for the diagnosis of TOS. There was very low quality evidence that transaxillary first rib resection decreased pain more than supraclavicular neuroplasty, but no randomized evidence that either is better than no treatment. There is moderate evidence to suggest that treatment with BTX injections yielded no great improvements over placebo injections of saline. There is no evidence from RCTs for the use of other currently used treatments. There is a need for an agreed definition for the diagnosis of TOS, especially the disputed form, agreed outcome measures, and high quality randomized trials that compare the outcome of interventions with no treatment and with each other.