Gustatory Side Effects After Thoracoscopic Sympathectomy

[Etiology and pathophysiology of Frey syndrome]

Frey syndrome is a late complication after parotidectomy and represents an aberrant regeneration of the auricular nerve after its damage. The degree of manifestation can vary from minor hyperemia to the inability to eat in public places. As it turned out, the etiology of this syndrome is much broader than we might have assumed, as evidenced by the data of domestic and foreign literature. The role of neurotrophic factors in the context of the pathophysiology of Frey syndrome has been the latest clue since its interpretation by Lucia Frey in 1923. The review highlights the various etiological and pathophysiological components of Frey syndrome that help the clinician in his medical practice.

Frey's Syndrome: A Review of Aetiology and Treatment

First described by Polish Neurologist Łucja Frey in 1923, Frey's syndrome (FS), or auriculotemporal syndrome, is a rare condition characterised by gustatory sweating, typically encountered as sequelae following invasive head and neck surgery. The pathophysiology of FS can be described by aberrant reinnervation of postganglionic parasympathetic neurons to the surrounding denervated sweat glands and cutaneous blood vessels. Multiple invasive procedures have been associated with FS ranging from salivary gland surgery to burn reconstruction and thoracoscopic sympathectomies. Rarely, FS can be secondary to trauma or non-surgical aetiologies, including diabetes and infection. Physical symptoms vary based on the severity and surface area affected by FS and range from mild symptoms to severe psychosocial morbidity for patients. Surgeons operating in the head and neck, including otolaryngologists, maxillofacial surgeons, and plastic surgeons, should be aware of this potential complication and be up to date with diagnosis and treatment strategies for FS. This review article summarises the literature relating to FS focusing on its aetiologies, symptomatology, prevention, and available treatments, aiming to provide an up-to-date review of this condition for surgeons operating in the head and neck region. Although various treatment options have been suggested, these are often limited to topical agents that require life-long administration for symptom control. Further research is recommended to identify the optimal treatment for this condition and the role of surgery as a treatment for severe or refractory cases.

Neural control of sweat secretion: a review

BACKGROUND

Humans have 4 million exocrine sweat glands, which can be classified into two types: eccrine and apocrine glands. Sweat secretion, a constitutive feature, is directly involved in thermoregulation and metabolism, and is regulated by both the central nervous system (CNS) and autonomic nervous system (ANS).

OBJECTIVES

To explore how sweat secretion is controlled by both the CNS and the ANS and the mechanisms behind the neural control of sweat secretion.

METHODS

We conducted a literature search on PubMed for reports in English from 1 January 1950 to 31 December 2016.

RESULTS AND CONCLUSIONS

Acetylcholine acts as a potent stimulator for sweat secretion, which is released by sympathetic nerves. β-adrenoceptors are found in adipocytes as well as apocrine glands, and these receptors may mediate lipid secretion from apocrine glands for sweat secretion. The activation of β-adrenoceptors could increase sweat secretion through opening of Ca²⁺ channels to elevate intracellular Ca²⁺ concentration. Ca²⁺ and cyclic adenosine monophosphate play a part in the secretion of lipids and proteins from apocrine glands for sweat secretion. The translocation of aquaporin 5 plays an important role in sweat secretion from eccrine glands. Dysfunction of the ANS, especially the sympathetic nervous system, may cause sweating disorders, such as hypohidrosis and hyperhidrosis.

T3 versus T4 thoracoscopic sympathectomy for palmar hyperhidrosis: a meta-analysis and systematic review

BACKGROUND

Palmar hyperhidrosis (PH) is a benign sympathetic disorder that can adversely affect the quality of life of patients. Thoracic sympathectomy (TS) at the T3 or T4 level has been used to treat PH. We aimed to determine the optimal denervation level for TS by comparing the efficacy of T3 TS versus T4 TS in PH patients.

METHODS

We searched the PubMed, Ovid MEDLINE, EMBASE, Web of Science, ScienceDirect, the Cochrane Library, Scopus, and Google Scholar databases for studies comparing T3 versus T4 TS for PH. Clinical end points included symptom resolution, patient satisfaction, and complications.

RESULTS

Of 2201 articles reviewed, 10 (T3 group, 566 patients; T4 group, 629 patients) were selected. T4 TS was associated with a lower incidence of postoperative compensatory sweating, dry hands, and gustatory sweating than T3 TS. No significant difference in symptom resolution or patient satisfaction was found between the T3 and T4 groups.

CONCLUSIONS

T4 TS may be superior to T3 TS in patients with PH. However, this finding should be validated in high-quality, large-scale randomized controlled trials.

Optimal targeting of sympathetic chain levels for treatment of palmar hyperhidrosis: an updated systematic review

BACKGROUND

Palmar hyperhidrosis involves excessive sweating of the palms, with no known etiology. Endoscopic thoracic sympathectomy (ETS) is a safe and effective treatment for palmar hyperhidrosis, but compensatory hyperhidrosis is a common complication after ETS, leading to reduced patient satisfaction and postoperative quality of life. However, the appropriate level of the sympathetic chain to target with ETS to achieve maximum efficacy and reduce the risk of compensatory hyperhidrosis (CH) is controversial. In this systemic review, we investigated the appropriate level of sympathectomy for palmar hyperhidrosis.

METHODS

PRISMA guidelines were implemented to complete a systematic review. We performed a computerized systematic literature search using PubMed and EMBASE from January 1990 to July 2016. We chose the Cochrane Collaboration's tool and the methodological index for non-randomized studies tool for examining study bias.

RESULTS

A total of 4075 citations were identified, of which 91 were eligible for inclusion, including 68 observational studies and 23 comparative trials. In observational studies, sympathectomies showed similar efficacies for curing PH at different levels. However, T2-free groups (i.e., at levels T3, T4, or T3-T4 combined) could render a lower risk of Horner's syndrome (0 vs. 1.21 ± 0.49%, p = 0.036) and CH (28.75 ± 7.25 vs. 57.46 ± 3.86, p = 0.002) compared with T2 involved. In comparative trials, there were 12 studies describing the comparison between T2-free ETS and T2 involved, and 9 of 12 (75%) showed T2-free ETS could reduce the incidence of CH. Overall, lowering the level and limiting the extent of sympathectomy could reduce the incidence of complications.

CONCLUSIONS

Cumulative data from more than 13,000 patients suggest that ETS is a safe, effective, and reproducible procedure with a high degree of patient satisfaction. Currently available evidence suggests that T2-free ETS may reduce the incidence of compensatory hyperhidrosis without compromising success rates and safety.

Single-Port Microthoracoscopic Sympathicotomy for the Treatment of Primary Palmar Hyperhidrosis: an Analysis of 56 Consecutive Cases

The objective of this study is to investigate the feasibility and safety of single-port microthoracoscopic thoracic sympathicotomy for the treatment of palmar hyperhidrosis. Between January 2008 and March 2013, 56 patients (36 male, 20 female; mean age 25.6 years, age range 16-39 years) underwent single-port microthoracoscopic thoracic sympathicotomy for palmar hyperhidrosis. Nineteen patients (33.9 %) had moderate palmar hyperhidrosis that could thoroughly wet a handkerchief, and 37 (66.1 %) had severe palmar hyperhidrosis with sweat dripping from the palm. Eight patients (14.3 %) had a positive family history, 34 (60.7 %) had plantar hyperhidrosis, 22 (39.3 %) had axillary hyperhidrosis, and 20 (35.7 %) had both plantar and axillary hyperhidrosis. In addition, 21 patients (37.5 %) had palmar pompholyx, five (8.9 %) had keratolysis exfoliativa, 10 (17.9 %) had chilblains, and nine (16.1 %) had palmar rhagades. A single 10-mm skin incision was made in the third intercostal space at the anterior axillary line, posterior to the pectoralis muscle. A 5-mm microthoracoscope and a 3-mm microelectrocautery hook were inserted through a single port into the thoracic cavity. The third and fourth ribs were identified, and the sympathetic chain was cut using the microelectrocautery hook. The bypassing nerve fibers, such as the Kuntz nerve fiber bundle, were ablated for 2-3 cm along the surface of the rib. The palmar temperature was recorded before and after sympathicotomy. All 56 procedures were completed using single-port microthoracoscopy. No postoperative complications such as hemorrhage, wound infection, hemopneumothorax, bradycardia, or Horner's syndrome were observed. Bilateral procedures were completed in 20-56 min (mean 30 min). The palmar temperature increased by 2.2 ± 0.3 °C after surgery. The postoperative hospital stay was 1-4 days (mean 2.5 days). Mild compensatory sweating of the back and thigh occurred in five patients (8.9 %) at 2-3 days after surgery and disappeared at 7-15 days. The patients were followed up for 28.5 months (range 1-62 months). Hyperhidrosis resolved in both hands after surgery, and the previously wet, cold hands became dry and warm. The efficacy rate was 100 %. Plantar hyperhidrosis was also significantly reduced in 33 of the 34 patients with this condition (remission rate 97.1 %), and axillary hyperhidrosis was significantly reduced in 19 of 22 patients (remission rate 86.4 %). Eighteen of the 20 patients (90.0 %) with both plantar and axillary hyperhidrosis experienced significant alleviation of their symptoms. Single-port microthoracoscopic thoracic sympathicotomy is a safe, convenient, and effective method of treating palmar hyperhidrosis. This procedure can accurately locate the sympathetic chain with a small incision, minimal invasiveness, and good cosmetic results. The procedure is suitable for extensive clinical use.

Sympathetic block by metal clips may be a reversible operation

OBJECTIVES

Thoracoscopic sympathectomy is now used routinely to treat patients with disabling primary hyperhidrosis or facial blushing. Published results are excellent, but side effects, such as compensatory sweating, are also very frequent. The surgical techniques used and the levels of targeting the sympathetic chain vary tremendously. Most surgeons transect or resect the sympathetic chain, but application of a metal clip that blocks transmission of nerve impulses in the sympathetic chain is used increasingly worldwide. This approach offers potential reversibility if patients regret surgery, but the question of reversibility remains controversial. Two recent experimental studies found severe histological signs of nerve damage 4-6 weeks after clip removal, but they only used conventional histopathological staining methods.

METHODS

Thoracoscopic clipping of the sympathetic trunk was performed in adult sheep, and the clip was removed thoracoscopically after 7 days. Following another 4 weeks (n = 6) or 12 weeks (n = 3), the sympathetic trunks were harvested and analysed by conventional and specific nerve tissue immunohistochemical stains (S100, neurofilament protein and synaptophysin). The contralateral sympathetic chains were used as controls.

RESULTS

Conventional and immunohistochemical stains demonstrated severe signs of neural damage on the operated side 4 weeks after clip removal. After 12 weeks, these changes had decreased markedly and conventional histology had almost normalized.

CONCLUSIONS

Conventional and immunohistochemical stains confirmed that application of metal clips to the sympathetic chain caused severe histological damage in the sympathetic trunk that remained visible 4 weeks after clip removal. However, after 12 weeks, these signs of damage had clearly decreased, which suggests in theory that application of metal clips to the sympathetic chain is a reversible procedure if only the observation period is prolonged. Further studies with longer periods between application and removal as well as investigations of nerve conduction should be encouraged, because we do not know whether histological reversibility at cellular level translates into physiological reversibility and possible correlation of nerve trauma with the duration of the applied clip.

Evidence-based review of the surgical management of hyperhidrosis

The great majority of the currently available evidence supporting sympathectomy for primary hyperhidrosis is observational, coming from a variety of prospective and restrospective clinical series as well as comparative studies. A cumulative experience in over 6000 patients suggests that ETS is a safe, reproducible, and effective procedure, and most patients are satisfied with the results of the surgery. The currently available experimental data comes from clinical trials that compared alternative levels of sympathetic chain disruption; these trials speak only to the relative merits of one surgical technique over another and do not provide an assessment of the overall impact of surgery in the general population of patients with primary hyperhidrosis. Furthermore, it is difficult to compare series and generalizability is compromised by a lack of uniform definitions and measures at both the exposure and outcome levels. There is marked heterogeneity with respect to study population and entry criteria, with significant variability of site and severity of excess sweating as well as the degree of preoperative conservative management of hyperhidrosis before surgical referral. Also the operative approach varies widely among studies, and the optimal procedure remains elusive: unilateral versus staged nonsimultaneous bilateral versus concomitant bilateral sympathectomy; ganglionic resection versus ablation using electrocoagulation or harmonic scalpel; clipping of the chain to maintain reversibility in the event of intolerable symptoms versus permanent disruption. In addition, the lack of uniform outcome measures makes these data difficult to interpret, and standardized metrics of surgical results are necessary, such as objective quantification of sweating by gravimetry or use of the SF-36 Health Survey Questionnaire as an estimate of patient quality of life. A multicenter, adequately powered, randomized controlled trial comparing surgical to medical management of hyperhidrosis is unlikely given the current enthusiasm for same-day thoracoscopic sympathectomy among surgeons, a largely positive literature replete with encouraging results, and well-informed hyperhidrosis patients who want to be cured of a socially debilitating illness. Future clinical trials in this area will likely compare surgical techniques. For such comparisons, procedures must be standardized and outcome measures validated for both symptoms of the disease and surgical complications. Finally, the studies must have large numbers of patients and adequate long-term follow-up if they are to detect differences in results among procedures with very high technical success rates.

Management of facial blushing

Patients complaining of facial blushing should be investigated by a dermatologist or an internist to rule out serious underlying disorders. Patients with emotionally triggered blushing should be encouraged to try nonsurgical options as the first line of treatment. Provided there is still an indication for treatment, facial blushing may be treated effectively by thoracoscopic sympathectomy. The type of blushing likely to benefit from sympathectomy is mediated by the sympathetic nerves and is the uncontrollable, rapidly developing blush typically elicited when one receives attention from other people. Side effects are frequent, but most patients are satisfied with the operation. In the short term, the key to success in sympathetic surgery for facial blushing lies in a meticulous and critical patient selection and in ensuring that the patient is thoroughly informed about the high risk of side effects. In the long term, the key to success in sympathetic surgery for facial blushing lies in more quality research comparing surgical, pharmacologic, and psychotherapeutic treatments.

Treatment of palmar hyperhidrosis: T(4) level compared with T(3) and T(2)

OBJECTIVE

The aim of this study was to compare the outcomes of 3 different levels of sympathectomy.

SUMMARY BACKGROUND DATA

Most surgeons still perform T(2) or T(2-3) sympathectomy for palmar hyperhidrosis, but both these treatments can cause severe side effects. Some recent articles have advocated T(4) sympathectomy and obtained satisfactory results.

METHODS

Between January 2000 and August 2004, 234 records of patients treated for palmar hyperhidrosis were retrospectively reviewed. Of them, 86 patients were treated with endoscopic thoracic sympathectomy of T(2) (ETS(2)), 78 patients with ETS(3), and 70 patients with ETS(4). Follow-up data were collected using a telephone questionnaire with a scoring system. Multiple linear regressions were used to model markers for degree of satisfaction and severity of compensatory sweating (CS), including descriptive data, level of sympathectomy, clinical outcomes, and postoperative complications.

RESULTS

Mean follow-up was 47.1 +/- 17.2 months. All 3 levels of sympathectomy could have achieved comparable improvement of palmar hyperhidrosis (P = 0.162). However, 88.5% of the patients noticed CS. Patients with ETS(4) presented the lowest incidence of CS (P = 0.030), had the least severity of CS (beta = -1.537, P = 0.002), and felt the least palmar overdryness (P < 0.001). None expressed regret for the procedure in the ETS(4) group (P = 0.022). Being obese did not increase the incidence of CS, but the severity of CS was directly related to body mass index (beta = 0.917, P < 0.001). The patients would be more satisfied if the severity of CS was minimal (beta = -0.185, P = 0.002). The degree of satisfaction may decrease with time (beta = -0.025, P = 0.003) and was lower when their palms were overdry (beta = -1.463, P < 0.001).

CONCLUSIONS

Different from the current procedure of T(2) or T(3) sympathectomy for palmar hyperhidrosis, T(4) sympathectomy would be a better and more effective procedure with minimal long-term complications.

Endoscopic VATS sympathectomy: the uniportal technique

Presentation of the uniportal VATS sympathectomy technique: through a single port incision, a videothoracoscope, a diathermy hook and, if needed, a lung grasper are introduced into the pleural cavity. Upon identification of the sympathetic chain, the relevant ganglia are divided. By extending laterally the dissection, the aberrant accessory sympathetic nerve fibers are also severed. Anatomic variations are illustrated and an overview of the literature is presented.