Anatomical redistribution of sweating after T2–T3 thoracoscopic sympathicolysis: a study of 210 patients

Interventions for hyperhidrosis in secondary care: a systematic review and value-of-information analysis

BACKGROUND

Hyperhidrosis is uncontrollable excessive sweating that occurs at rest, regardless of temperature. The symptoms of hyperhidrosis can significantly affect quality of life. The management of hyperhidrosis is uncertain and variable.

OBJECTIVE

To establish the expected value of undertaking additional research to determine the most effective interventions for the management of refractory primary hyperhidrosis in secondary care.

METHODS

A systematic review and economic model, including a value-of-information (VOI) analysis. Treatments to be prescribed by dermatologists and minor surgical treatments for hyperhidrosis of the hands, feet and axillae were reviewed; as endoscopic thoracic sympathectomy (ETS) is incontestably an end-of-line treatment, it was not reviewed further. Fifteen databases (e.g. CENTRAL, PubMed and PsycINFO), conference proceedings and trial registers were searched from inception to July 2016. Systematic review methods were followed. Pairwise meta-analyses were conducted for comparisons between botulinum toxin (BTX) injections and placebo for axillary hyperhidrosis, but otherwise, owing to evidence limitations, data were synthesised narratively. A decision-analytic model assessed the cost-effectiveness and VOI of five treatments (iontophoresis, medication, BTX, curettage, ETS) in 64 different sequences for axillary hyperhidrosis only.

RESULTS AND CONCLUSIONS

Fifty studies were included in the effectiveness review: 32 randomised controlled trials (RCTs), 17 non-RCTs and one large prospective case series. Most studies were small, rated as having a high risk of bias and poorly reported. The interventions assessed in the review were iontophoresis, BTX, anticholinergic medications, curettage and newer energy-based technologies that damage the sweat gland (e.g. laser, microwave). There is moderate-quality evidence of a large statistically significant effect of BTX on axillary hyperhidrosis symptoms, compared with placebo. There was weak but consistent evidence for iontophoresis for palmar hyperhidrosis. Evidence for other interventions was of low or very low quality. For axillary hyperhidrosis cost-effectiveness results indicated that iontophoresis, BTX, medication, curettage and ETS was the most cost-effective sequence (probability 0.8), with an incremental cost-effectiveness ratio of £9304 per quality-adjusted life-year. Uncertainty associated with study bias was not reflected in the economic results. Patients and clinicians attending an end-of-project workshop were satisfied with the sequence of treatments for axillary hyperhidrosis identified as being cost-effective. All patient advisors considered that the Hyperhidrosis Quality of Life Index was superior to other tools commonly used in hyperhidrosis research for assessing quality of life.

LIMITATIONS

The evidence for the clinical effectiveness and safety of second-line treatments for primary hyperhidrosis is limited. This meant that there was insufficient evidence to draw conclusions for most interventions assessed and the cost-effectiveness analysis was restricted to hyperhidrosis of the axilla.

FUTURE WORK

Based on anecdotal evidence and inference from evidence for the axillae, participants agreed that a trial of BTX (with anaesthesia) compared with iontophoresis for palmar hyperhidrosis would be most useful. The VOI analysis indicates that further research into the effectiveness of existing medications might be worthwhile, but it is unclear that such trials are of clinical importance. Research that established a robust estimate of the annual incidence of axillary hyperhidrosis in the UK population would reduce the uncertainty in future VOI analyses.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015027803.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

[Primary hyperhidrosis. Current status of surgical treatment]

Primary hyperhidrosis-PH is an excessive sweating without known etiology. The PH is more frequent in women and in palms, soles and axillae. Medical treatment is not effective. The objective of the surgery is to remove or to disconnect sympathetic ganglia T2 (craniofacial PH or facial blushing), T3 (palmar PH) and T3-T4 (axillary PH). The surgical techniques are mainly resection/transection, ablation with electrocoagulation, sympathetic block by clipping and radiofrequency. Anhidrosis is achieved in 95% of the patients. The overall rate of complications is less than 5% and these are minor complications. The most important unwanted effect is reflex sweating, presented in 48% of the patients. Reflex sweating is more frequent in back, thorax and abdomen and it appears independently of the surgical technique. Ninety percent of the patients are very satisfied after surgery. Nowadays, thoracic sympathetic surgery is the gold standard for primary hyperhidrosis.

Anatomical variations of the upper thoracic sympathetic chain

The aim is to clearly delineate the upper thoracic sympathetic chains and neural connections between the chains and ventral rami of the thoracic nerves, and to provide an anatomical foundation for successful upper thoracic sympathicotomy for treating upper essential hyperhidrosis. The upper thoracic sympathetic chains, upper five intercostal nerves, and neural connections between them in 50 halves of 25 adult cadavers have been dissected, measured, and mapped. The stellate ganglion had an incidence of 80%. The second to the fourth thoracic sympathetic ganglia were commonly located in the corresponding intercostal spaces with the presence of 92%, 68%, and 50%, respectively. The incidence of the first and second intercostal rami was 40% and 6%, and that of the ascending or descending rami from the second, third and fourth ganglia was 54%, 24%, and 14%, respectively. Additional rami communicantes joined the ventral ramus of the 1st thoracic nerve proximal to the point where the latter gave a branch to the brachial plexus. The farthest horizontal distance from the sympathetic chain to the junction between the additional rami communicantes and the second to the fourth intercostal nerves was 29.1 mm. Only 16% of cadavers had similar anatomy bilaterally. Anatomical variations of the upper thoracic sympathetic trunk in relation to intercostal nerves, which may be one of the causes resulting in surgical failures and recurrences, were striking. Attention should be given to such anatomical variations when planning thoracic sympathicotomy.

Quantification of eccrine sweat glands with acetylcholine sweat-spot test and anatomical redistribution of sweating after T2-T3 thoracoscopic sympathicolysis

BACKGROUND

In this study, patients treated by thoracoscopic sympathicolysis for palmar hyperhidrosis were evaluated to determine the number and response of sweat glands to intradermal acetylcholine stimulus.

METHODS

A total of 30 patients were included in the study. Group A consisted of 10 patients with palmar hyperhidrosis who underwent thoracoscopic sympathicolysis in October 2005, and group B consisted of 20 patients who underwent surgery during the years 1999, 2000, and 2001. The study procedure involved applying iodine alcohol to the palm and then intradermally injecting 0.1 ml 1% acetylcholine. This activated the sweat glands, which were then photographed and counted. The study procedure was performed prospectively over different periods in group A and retrospectively in group B.

RESULTS

In group A, the mean number of glands activated 1, 3, 6, and 12 months after surgery were 41, 174.20, 522.8, and 747.2, respectively; this gradual increase was statistically significant over the first 6 months (p = 0.004) but not between months 6 and 12 (p = 0.255). The trend towards an increasing number of active glands occurred in both groups, with a mean of 1369.8 active glands in group B compared to 747.2 (p = 0.095) in group A after 12 months.

CONCLUSION

It is well-known that Cannon's law of denervation (1939) is not applicable to the sweat glands, that is, there is no hyperactivation following intradermal acetylcholine stimulation. However, some response, which increased over the first 6 months following surgery, was observed in our study. Nevertheless, this activation is subsequently self-limiting, resulting in no gland atrophy, and reinnervation occurs without patient awareness.