This is a plain English summary of an original research article
For treatment of severe sweaty palms, minimally invasive surgery to cut the sympathetic nerves at a single level, reduces the commonest complications of the procedure. This review looked at the studies of cuts made at different levels and found that compensatory sweating elsewhere in the body was minimised if the cuts were made at the level of the fourth thoracic vertebra. The success in controlling sweaty palms and patient satisfaction were similar whatever level was cut in these trials.
Excessive sweating of the palms (palmar hyperhidrosis) is distressing, uncomfortable and can lead to difficulties with everyday tasks. Lifestyle measures, medication and botox injections can help in mild to moderate cases, but severe cases may require surgery. Video-assisted thoracoscopic sympathectomy surgery is becoming increasingly common as a last resort for severe symptoms. This minimally-invasive procedure is performed fairly rarely and there remains some uncertainty about how best to do it. Compensatory sweating is common after the procedure and although studies have been undertaken to look at this, the studies have not yet been combined in a single analysis.
This review may inform surgical practice but is a highly specialist procedure. Commissioners may need to consider training implications and the capacity of units to deal with any complications that arise from increased use.
Why was this study needed?
Ongoing and long-lasting excessive sweating affects around 1-3% of the UK population. When this affects the palms, it can cause embarrassment, for example when shaking hands, and difficulties with day-to-day tasks such as driving or holding a pen.
Initial management usually involves lifestyle measures such as wearing loose clothes, avoiding known triggers and using antiperspirants. If these are not effective, other treatments include using mild electrical currents on the palms (iontophoresis), medications and botox injections.
Surgery to cut the nerves that run along the rib cage and control sweating in the palms can be used as a last resort. Usually this is performed using a minimally invasive technique – video-assisted thoracoscopic sympathectomy (VTS). About 58 of these procedures were recorded nationally by NHS Digital in 2014.
This systematic review aimed to combine the results of existing studies and assess whether there was any difference in the likelihood of adverse events depending on which segmental level was cut.
What did this study do?
This review identified eight randomised controlled trials of VTS for excessive sweating of the palms, including a total of 1,200 people (between 20 and 207 people in each study). The trials compared whether cutting the sympathetic nervous chain at different levels affected the likelihood of compensatory sweating after surgery.
There was considerable variation between the trials included in this review. There was no agreed way of measuring compensatory sweating, and the time when this was assessed after surgery varied between one to 12 months. Therefore, it is hard to directly compare the number of people affected by compensatory sweating in each trial. This may reduce confidence in the primary finding of this review, but in the absence of larger trials these results reflect the current state of knowledge.
What did it find?
- There was no difference in the number of people experiencing compensatory sweating after VTS to cut single segments compared with multiple nerve segments. However, cutting single segments did reduce the risk of moderate to severe sweating compared to multiple segments (RR 0.42, 95% CI 0.22 to 0.80; two trials).
- When comparing cutting higher or lower segments, there was also no difference in the overall number of cases of compensatory sweating (OR 0.76, 95% CI 1.58 to 1.01), but cutting lower segments reduced the risk of moderate to severe sweating (OR 0.29, 95% CI 0.16 to 0.54).
- When looking at the specific segment cut, cutting at the level of the fourth thoracic vertebra (T4) segment was most effective. It was associated with significantly reduced risk of compensatory sweating (RR 0.70, 95% CI 0.59 to 0.83; three trials) and of moderate to severe compensatory sweating (RR 0.26, 95% CI 0.12 to 0.56; three trials) when compared with all other segments.
- There was no significant difference in compensatory sweating or its severity when comparing cutting either the T3 (eight trials) or T2 segments (two trials) when compared with other segments.
What does current guidance say on this issue?
NICE guidance on VTS (2014) highlights the potential for serious side effects, including severe compensatory sweating. Because of this, NICE recommended the procedure is only offered to people with sweating that is “severe and debilitating” and has not responded to conservative treatment. No recommendation is made about the segment level that is targeted as little evidence was available at the time. NICE recommends that potential side effects are discussed with patients to enable them to make an informed decision about their treatment.
What are the implications?
Overall this review suggests that the number and severity of cases of compensatory sweating may be reduced by cutting single, lower nerve segments – in particular T4 – rather than multiple or higher segments.
This review focused on the common complication of compensatory sweating after VTS, which is of high relevance to patients. However, it did not consider safety outcomes and there have been rare cases of serious complications such as lung collapse and major bleeding.
These findings may inform the techniques used by surgeons to perform this surgery and discussions with patients around potential complications.
Citation and Funding
Zhang W, Yu D, Jiang H, et al. Video-assisted thoracoscopic sympathectomy for palmar hyperhidrosis: a meta-analysis of randomized controlled trials. PLoS One. 2016;11(5):e0155184.
NHS Choices. Hyperhidrosis - treatment. London: Department of Health; 2015.
NICE. Endoscopic thoracic sympathectomy for primary hyperhidrosis of the upper limb. IPG487. London: National Institute for Health and Care Excellence; 2014.
NICE. Hyperhidrosis: oral glycopyrronium bromide. ESUOM16. London: National Institute for Health and Care Excellence; 2013.
NICE. Social anxiety disorder: recognition, assessment and treatment. CG159. London: National Institute for Health and Care Excellence; 2013.
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