The Etiology of Primary Hyperhidrosis: A Systematic Review.

PURPOSE: Primary hyperhidrosis is a pathological disorder of unknown etiology, affecting 0.6-5% of the population, and causing severe functional and social handicaps. As the etiology is unknown, it is not possible to treat the root cause. Recently some differences between affected and non-affected people have been reported. The aim of this review is to summarize these new etiological data. METHODS: Search of the literature was performed in the PubMed/Medline Database and pertinent articles were retrieved and reviewed. Additional publications were obtained from the references of these articles. RESULTS: Some anatomical and pathophysiological characteristics (as well as enzymatic, metabolic, and neurological dysfunctions) have been observed in hyperhidrotic subjects; three main possible etiological factors predominate. A familial trait seems to exist, and genetic loci associated with hyperhidrosis have been identified. Histological differences were observed in sympathetic ganglia of hyperhidrotic subjects: the ganglia were larger and contained a higher number of ganglion cells. A higher expression of acetylcholine and alpha-7 neuronal nicotinic receptor subunit in the sympathetic ganglia of patients with hyperhidrosis has been reported. CONCLUSIONS: Despite these accumulated data, the etiology of primary hyperhidrosis remains obscure. Nevertheless, three main lines for future research seem to be delineated: genetics, histological observations, and enzymatic studies.

Thoracic sympathectomy: a review of current indications.

BACKGROUND: Thoracic sympathetic ablation was introduced over a century ago. While some of the early indications have become obsolete, new ones have emerged. Sympathetic ablation is being still performed for some odd indications thus prompting the present study, which reviews the evidence base for current practice. METHODS: The literature was reviewed using the PubMed/Medline Database, and pertinent articles regarding the indications for thoracic sympathectomy were retrieved and evaluated. Old, historical articles were also reviewed as required. RESULTS AND CONCLUSIONS: Currently, thoracic sympathetic ablation is indicated mainly for primary hyperhidrosis, especially affecting the palm, and to a lesser degree, axilla and face, and for facial blushing. Despite modern pharmaceutical, endovascular and surgical treatments, sympathetic ablation has still a place in the treatment of very selected cases of angina, arrhythmias and cardiomyopathy. Thoracic sympathetic ablation is indicated in several painful conditions: the early stages of complex regional pain syndrome, erythromelalgia, and some pancreatic and other painful abdominal pathologies. Although ischaemia was historically the major indication for sympathetic ablation, its use has declined to a few selected cases of thromboangiitis obliterans (Buerger's disease), microemboli, primary Raynaud's phenomenon and Raynaud's phenomenon secondary to collagen diseases, paraneoplastic syndrome, frostbite and vibration syndrome. Thoracic sympathetic ablation for hypertension is obsolete, and direct endovascular renal sympathectomy still requires adequate clinical trials. There are rare publications of sympathetic ablation for primary phobias, but there is no scientific basis to support sympathetic surgery for any psychiatric indication.

Radiofrequency Thermotherapy for Treating Axillary Hyperhidrosis.

BACKGROUND: Thermotherapy has been established between conservative and surgical options as a minimally invasive method for the treatment of axillary hyperhidrosis. OBJECTIVE: The objective of this study was to present radiofrequency thermotherapy (RFTT) as a safe and effective new treatment method. MATERIALS AND METHODS: Thirty adult patients with pronounced axillary hyperhidrosis were treated with RFTT with noninsulated microneedles 3 times at intervals of 6 weeks. Subjective improvement was rated using the Hyperhidrosis Disease Severity Scale (HDSS) and Dermatology Life Quality Index (DLQI). Satisfaction and estimated reduction of sweating were monitored. Objective measurements were made using gravimetry. Adverse effects were recorded in follow-up. At the 6-month follow-up, improvement in sweating was seen in 27 patients. The HDSS dropped from 3.4 to 2.1, the DLQI improved significantly from 16 to 7. The gravimetric measurements of sweat were reduced from 221 to 33 mg/min. The average reduction of sweating was reported to be 72%. Adverse effects were generally mild and improved rapidly. CONCLUSION: Radiofrequency thermotherapy was shown to be an effective and minimally invasive treatment option for axillary hyperhidrosis. Patients described their sweating as normal. The method clearly has the potential to normalize axillary sweating.

Thermal bile duct and duodenal protection during pancreatic cryoablation.

AIM: To examine whether thermo-perfusion of the bile duct and duodenum may protect these organs during cryoablation of adjacent pancreatic tissue. STUDY DESIGN: Cryoablation of the pancreatic tissue, adjacent to the common bile duct and duodenum was performed in two groups of pigs. In the experimental group, the bile duct and duodenum were protected during the cryo-procedure by intraluminal perfusion of warm saline. In the control group, cryoablation was performed without thermo-protection. RESULTS: All three animals in the control group developed duodenal perforation and abscesses and died within a week. All the pigs in the experimental group survived and on re-operation 14 days after the first procedure were found to have normal duodenum and bile duct adjacent to the cryoablated pancreatic tissue. Histological examinations confirmed these results. CONCLUSION: The present study confirms the feasibility and efficacy of thermo-protection of the duodenum and common bile duct during cryoablation of the head of the pancreas.

Sentinel node detection in an animal study: evaluation of a new portable gamma camera.

We tested the capacity of a newly developed portable gamma camera to precisely locate sentinel nodes by injecting a radiotracer. Two sets of experiments were performed on eight pigs under general anesthesia. 99mTc-Nanocolloid and dye complex was injected in the submuscular layer of the small bowel in the first set and subcutaneously in the knee region in the second set of experiments. Image acquisition of the sentinel nodes was performed with the Camera placed at various angles. A mosaic of images was obtained encompassing the injection sites, lymphatic pathways, and sentinel lymph nodes. Three-dimensional visualizations were obtained, allowing the precise location and complete excision of these nodes. The use of the portable gamma camera allowed the rapid visualization of the lymphatic pathways leading from the injection sites to the sentinel nodes and precise location of these nodes. The Camera was also useful to verify the complete removal of the labeled target tissues.

The History of Sympathetic Surgery.

At present, primary hyperhidrosis is the main indication for sympathectomy. For upper thoracic sympathetic ablation, excision of the second thoracic ganglion alone or with the first and/or third ganglia was the standard during the open surgery era. With the advent of thoracoscopy, modifications related to the level, extent, and type of ablation were proposed to attenuate compensatory hyperhidrosis. The ideal operation for sympathetic denervation of the face and upper limbs remain to be defined. Controlled double-blind studies with quantitave measurements of sweat production are required.

Temperature-controlled laser-soldering system and its clinical application for bonding skin incisions.

Laser tissue soldering is a method of repairing incisions. It involves the application of a biological solder to the approximated edges of the incision and heating it with a laser beam. A pilot clinical study was carried out on 10 patients who underwent laparoscopic cholecystectomy. Of the four abdominal incisions in each patient, two were sutured and two were laser soldered. Cicatrization, esthetical appearance, degree of pain, and pruritus in the incisions were examined on postoperative days 1, 7, and 30. The soldered wounds were watertight and healed well, with no discharge from these wounds or infection. The total closure time was equal in both methods, but the net soldering time was much shorter than suturing. There was no difference between the two types of wound closure with respect to the pain and pruritus on a follow-up of one month. Esthetically, the soldered incisions were estimated as good as the sutured ones. The present study confirmed that temperature-controlled laser soldering of human skin incisions is clinically feasible, and the results obtained were at least equivalent to those of standard suturing.

The necrotizing effect of pulse cryocycling on liver tissue.

HYPOTHESIS: Repeated cycles of freezing improve the necrotizing effect of cryosurgery. We investigated whether multiple, very short periods of freezing and thawing (pulse cryocycling) enlarged the area of cell cryonecrosis within the iceball, compared with the standard method of cryocycling. DESIGN: Liver cryonecrosis was produced in 3 groups of rabbits by means of 2 cycles of 5-minute freezing processes, each followed by 5 minutes of spontaneous thawing. In the control group (group 1), the freezing periods were uninterrupted. In the pulse cryocycling groups, the freezing periods consisted of repeated episodes of freezing and active thawing of 15 seconds (group 2) or 30 seconds (group 3) each. The edges of all lesions were visually marked. The correlation between marking and borders of the cryolesion were examined ultrasonographically. All animals were killed on the following day, and the liver was harvested and examined histologically. SETTING: Animal experimental laboratory. RESULTS: Complete liver cell demise was observed up to the edge of the cryolesions in all 3 groups of animals. However, a thin, sharply bounded intermediate zone of incomplete tissue destruction was observed at the border of the cryolesions, which was relatively thicker in group 2. CONCLUSIONS: In our study, pulse cryocycling had no advantage compared with regular cryocycling, which obtained optimal results in normal liver tissue. However, compared with the 30-second cycles, the 15-second pulse cycling yielded poorer results.

Attempted reversible sympathetic ganglion block by an implantable neurostimulator.

OBJECTIVE: Primary palmar hyperhidrosis is a pathological condition of excessive perspiration of the hands of unknown aetiology. The only effective treatment for permanent cure is the ablation of the sympathetic ganglia supplying the hands. One of the sequelae is compensatory sweating, namely increased perspiration in other parts of the body. Its mechanism is unknown. In a small proportion of patients, it may attend devastating proportions. It has practically no remedy, and the degree of compensatory hyperhidrosis is unpredictable prior to sympathectomy. The purpose of the present study was to obtain a reversible sympathetic block which may disclose subjects prone to develop severe compensatory hyperhidrosis and unfit for permanent ganglionic ablation. METHODS: In three dogs, an experimental electrode was implanted via a left thoracotomy on the stellate ganglion, connected to a stimulator. The stimulation was activated after recovery. The contralateral ganglion served as control. Effect of the stimulation was assessed by observing the development of Horner's syndrome, which includes the appearance of miosis, ptosis and enophthalmus. Reversal of the sympathetic block was expected when the neurostimulation was discontinued and assessed by the disappearance of these signs. RESULTS: Stimulation produced only a partial effect - an incomplete Horner's syndrome (miosis and sometime ptosis), which was not completely reversible after ceasing the stimulation. CONCLUSIONS: Although neurostimulation achieved a partial sympathetic block, the present method failed to obtain a completely reversible effect. However, these results may indicate that different nervous pathways moderate the various components of the Horner's triad. Concerning the creation of a reversible sympathectomy; other approaches must be sought after.

The correlation between the method of sympathetic ablation for palmar hyperhidrosis and the occurrence of compensatory hyperhidrosis: a review.

BACKGROUND: Upper dorsal sympathectomy achieves excellent long-term results in the treatment of primary palmar hyperhidrosis. Compensatory hyperhidrosis (CHH) remains an unexplained sequel of this treatment, attaining in a small percentage of cases disastrous proportions. It has been claimed that lowering the level of sympathectomy (from T2 to T3 and even T4), substituting resection by other means of ablation, and limiting its extend reduce the occurrence of this sequel. This review was designed to evaluate the validity of these claims. METHODS: A MEDLINE search was performed for the years 1990--2006 and all publications about thoracoscopic upper dorsal sympathectomy for hyperhidrosis were retrieved. RESULTS: The search identified 42 techniques of sympathetic ablation. However, pertinent data for the present study were reported for only 23 techniques with multiple publications found only for 10. The only statistically valid results from this review point that T2 resection and R2 transection of the chain (over the second rib) ensue in less CHH than does electrocoagulation of T2. Further comparisons were probably prevented due to the enormous disparity in the reported results, indicating lack of standardization in definitions. CONCLUSIONS: The compiled results published so far in the literature do not support the claims that lowering the level of sympathetic ablation, using a method of ablation other than resection, or restricting the extend of sympathetic ablation for primary palmar hyperhidrosis result in less CHH. In the future, standardization of the methods of retrieving and reporting data are necessary to allow such a comparison of data.

Thoracoscopic sympathectomy for primary palmar hyperhidrosis: resection versus transection -- a prospective trial.

Upper dorsal sympathectomy is the only successful therapeutic method for idiopathic palmar hyperhidrosis (IPHH). However, the techniques for sympathetic ablation are still debated. The aim of this study was to compare prospectively two accepted methods for endoscopic sympathetic ablation: resection of T2-T3 ganglia versus transection of the chain over the second to fourth ribs. During the period September 2000 to June 2002, a total of 32 patients with IPHH were operated on. Operations were performed under general anesthesia through two 5-mm trocars using electrocautery. Resection was done on one side and transection on the other, with both sides being addressed during the same operation. The sides of resection/transection were alternated at each operation. There were 14 men and 18 women aged 18.8 +/- 4.7 years. The mean operating times for sympathectomy were 12.0 +/- 3.1 minutes for resection and 6.6 +/- 1.9 minutes for transection (p = 1.38). All patients were examined at 2 weeks postoperatively and again at 1 month. During November-December 2005, patients were approached by telephone questionnaire, the mean follow-up period being 4.3 +/- 0.9 years. Altogether, 26 of the 32 patients could be located (15 women, 11 men). There was no significant difference with regards to perioperative complications, immediate or long-term pain. All but two hands were warm and dry 1 month after operation and remained so at follow-up. The exceptions included one hand with recurrent hyperhidrosis after 1.5 years and one that became less dry and cold at 3 years. Both were on the transected sides. Our results suggest that sympathetic resection may achieve slightly better long-term results than transection in patients with IPHH. Large-scale prospective studies are needed to confirm these results.