出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/09/13 14:56:05」(JST)
| Endoscopic thoracic sympathectomy | |
|---|---|
| Intervention | |
| ICD-9-CM | 05.2 |
| MedlinePlus | 007291 |
Endoscopic thoracic sympathectomy (ETS) is a controversial surgical procedure where certain portions of the sympathetic nerve trunk are destroyed. ETS is used to treat hyperhidrosis, facial blushing, Raynaud's disease and reflex sympathetic dystrophy. By far the most common complaint treated with ETS is palmar hyperhidrosis, or colloquially known as "sweaty palms".
Sympathectomy physically destroys relevant nerves anywhere in either of the two sympathetic trunks, which are long chains of nerve ganglia located bilaterally along the vertebral column (situated to reduce the potential for injury) responsible for various important aspects of the peripheral nervous system (PNS). Each nerve trunk is broadly divided into three regions: cervical (neck), thoracic (chest), and lumbar (lower back). The most common area targeted in sympathectomy is the upper thoracic region, that part of the sympathetic chain lying between the first and fifth thoracic vertebrae.
In addition to the normal risks of surgery, such as bleeding and post-operative infection, sympathectomy has several specific risks, such as irreparable adverse changes in how nerves function.
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ETS is most commonly used to treat severe hyperhidrosis of the upper body, Raynaud's phenomenon, and facial blushing.
There are reports of ETS being used to achieve cerebral revascularization for patients with moyamoya disease,[1] and to treat headaches, hyperactive bronchial tubes,[2] long QT syndrome[3][4][5] and other conditions.
Thoracic sympathectomy can alter many bodily functions, including sweating,[6] vascular responses,[7] heart rate,[8][9] heart stroke volume,[10][11] thyroid, baroreflex,[12]lung volume,[11][13] pupil dilation, skin temperature, goose bumps and other aspects of the autonomic nervous system, like the fight-or-flight response. It reduces the physiological responses to strong emotion, and may diminish the body's physical reaction to exercise.[6][11][14]
Sympathectomy involves division of adrenergic, cholinergic and sensory fibers which elaborate adrenergic substances during the process of regulating visceral function.[15] It involves dissection of the main Sympathetic trunk in the upper thoracic region of the sympathetic nervous system, thus interrupting neural messages that ordinarily would travel to many different organs, glands and muscles. It is via these nerves of the autonomic nervous system that the brain is able to make adjustments in the body in response to changing conditions in the environment, changing emotional states, level of exercise, and other factors to maintain the body's homeostasis. This normative function is disabled or impaired by sympathectomy, because the functions these physiological mechanisms perform also regulate conditions like blushing or hyperhidrosis, that the procedure is designed to eliminate.
There is much disagreement among ETS surgeons about the best surgical method, optimal location for nerve dissection, and the nature and extent of the consequent primary effects and side effects. When performed endoscopically as is usually the case, the surgeon penetrates the chest cavity, making incisions about the diameter of a straw between ribs. This allows the surgeon to insert the video camera (endoscope) in one hole and a surgical instrument in another. The operation is accomplished by dissecting the nerve tissue of the main sympathetic chain. The clamping method, also referred to as endoscopic sympathetic blockade (ESB) employs titanium clamps around the nerve tissue, and was developed in an unsuccessful attempt to make the procedure reversible. However, technical reversal of the clamping procedure must be performed within a short time after clamping (a few days or weeks at most), and a recovery, evidence suggests, will not be complete.
Sympathectomy works by disabling part of the autonomic nervous system (and thereby disrupting its signals from the brain), through surgical intervention, in the expectation of removing or alleviating the problem. Many non-ETS doctors have found this practice questionable chiefly because its purpose is to destroy anatomically normal, but functionally disordered, nerves.[16]
Exact results of ETS are impossible to predict, because of considerable anatomic variations in nerve function from one patient to the next, and also because of variations in surgical technique. The autonomic nervous system is not anatomically exact and connections might exist with different parts of the body. This theory has been proven by the fact that a significant number of patients who have had sympathectomy for hand sweating might notice a reduction or elimination of feet sweating, in contrast to others who do not. No reliable operation exists for foot sweating per se except lumbar sympathectomy, at the opposite end of the SNS chain.
Lumbar sympathectomy is largely of historical interest today, being reserved for cases of severe sympathetic dystrophy or selected cases of rest pain, where is it usually done by percutaneous ablation of the lumbar sympathetic chain by phenol injection under imaging guidance. Its original use as an operation for lower limb ischaemia has been superseded by direct revascularisation operations or endovascular revacularisation procedures such as angioplasty or angioplasty with stenting of occuded arteries with reasonable runoff i.e. endovascular surgery.
A large study of psychiatric patients treated with this surgery showed significant reductions in fear, alertness and arousal. (Teleranta, Pohjavaara, et al. 2003, 2004. Online link unavailable). Arousal is essential to consciousness, in regulating attention and information processing, memory and emotion.[17]
ETS patients are being studied using the autonomic failure protocol headed by David Goldstein, M.D. Ph.D., senior investigator at the U.S National Institute of Neurological Disorders and Stroke. He has documented loss of thermoregulatory function, cardiac denervation, and loss of vasoconstriction.[18] Recurrence of the original symptoms due to nerve regeneration or nerve sprouting can occur within the first year post surgery. Nerve sprouting, or abnormal nerve growth after damage or injury to the nerves can cause other further damage. Sprouting sympathtetic nerves can form connections with sensory nerves, and lead to pain conditions that are mediated by the SNS. Every time the system is activated, it is translated into pain. This sprouting and its action can lead to Frey's syndrome, a recognized after effect of sympathectomy, when the growing sympathetic nerves innervate salivary glands, leading to excessive sweating regardless of environmental temperature through olfactory or gustatory stimulation.
No surgery is risk-free, and ETS has both the normal risks of surgery, such as bleeding and infection, and several specific risks, including permanent and unavoidable changes in nerve function. A number of patients, mostly young women, have died during this procedure. Bleeding during and following the operation may be significant in up to 5% of patients.[19] Pneumothorax (collapsed lung) can occur (2% of patients).[19]
Compensatory hyperhidrosis (sweating) is common over the long term, causing 1% to 2% patients in one review to regret having had the surgery.[19] The rates of severe compensatory sweating vary widely between studies, ranging from as low as 1.2% and as high as 30.9% of patients.[20] Of those patients that develop this side effect, about a quarter said it was major and disabling.[21]
A severe possible consequence of thoracic sympathectomy is corposcindosis (split-body syndrome), in which the patient feels that he or she is living in two separate bodies, because sympathetic nerve function has been divided into two distinct regions, one dead, and the other hyperactive. [20]
Additionally, the following side effects have all been reported by patients:[citation needed] Chronic muscular pain, numbness and weakness, Horner Syndrome, anhidrosis, neuralgia, paraesthesia, fatigue and amotivationality, breathing difficulties, substantially diminished physiological/chemical reaction to internal and environmental experience (e.g. pleasure and pain/ perceptual stimuli), somatosensory malfunction, aberrant physiological reaction to stress and exertion etc., Reynaud’s disease onset by cold weather etc. (ironically a possible indication for surgery), reflex hyperhidrosis (or compensatory sweating see above) present in all areas excluding those beset with anhidrosis, systemic thermoregulatory dysfunction (hyperthermia), altered/erratic blood pressure and circulation, defective fight or flight response system (discussed above), loss of adrenaline (see above), eczema and other skin conditions such as keratosis polaris (in consequence of unmoisturized skin in areas affected by anhidrosis), rhinitis, gustatory sweating (or Frey's syndrome, see above).
Some long-term adverse effects include:
Other side effects are the inability to raise the heart rate sufficiently during exercise with instances requiring an artificial pacemaker after developing bradycardia being reported as a consequence of the surgery.[27][28][22]
The Finnish Office for Health Care Technology Assessment concluded in a 400 page systematic review that Endoscopic Thoracic Sympathectomy is associated with an unusually high number of significant immediate and long-term adverse effects.[29]
Quoting the Swedish National Board of Health and Welfare statement: "The method can give permanent side effects that in some cases will first become obvious only after some time. One of the side effects might be increased perspiration on different places on your body. Why and how this happens is still unknown. According to the research available about 25-75% of all patients can expect more or less serious perspiration on different places on their body, such as the trunk and groin area, this is Compensatory sweating".[30][not in citation given]
In 2003, ETS was banned in its birthplace, Sweden, due to overwhelming complaints by disabled patients. In 2004, Taiwanese health authorities banned the procedure on patients under 20 years of age. In other countries it is a notoriously unregulated procedure.
The internet now features many websites run by surgeons extolling the benefits of ETS. However, there are also many websites run by disabled ETS victims who complain of severe adverse reactions leading to decreased ability to perform ones occupation and daily activities and a perceived lack of adequate informed consent. Several online discussion forums are dedicated to the subject of ETS surgery, where patient testimonials abound.
Sympathectomy developed in the mid-19th century, when it was learned that the autonomic nervous system runs to almost every organ, gland and muscle system in the body. It was surmised that these nerves play a role in how the body regulates many different body functions in response to changes in the environment, exercise, emotion and pleasure.
The first sympathectomy was performed by Alexander in 1889.[31] Since the sympathetic nervous system was well known to affect many body systems, the surgery was performed in attempts to treat many conditions, including idiocy, goitre, epilepsy, glaucoma, and angina pectoris. Thoracic sympathectomy has been indicated for hyperhidrosis (excessive sweating) since 1920, when Kotzareff showed it would cause anhidrosis (total inability to sweat) from the nipple line upwards.[6]
A lumbar sympathectomy was also developed and used to treat excessive sweating of the feet and other ailments, and typically resulted in impotence in men. Lumbar sympathectomy is still being offered as a treatment for plantar hyperhidrosis, or as a treatment for patients who have a bad outcome (extreme 'compensatory sweating') after thoracic sympathectomy for palmar hyperhidrosis or blushing; extensive sympathectomy risks hypotension.
Sympathectomy itself is relatively easy to perform; however, accessing the nerve tissue in the chest cavity by conventional surgical methods was difficult, painful, and spawned several different approaches. The posterior approach was developed in 1908, and required resection (sawing off) of ribs. A supraclavical (above the collar-bone) approach was developed in 1935, which was less painful than the posterior, but was more prone to damaging important nerves and blood vessels. Because of these difficulties, and because of disabling sequelae associated with sympathetic denervation, conventional or "open" sympathectomy was never a very popular procedure, although it continued to be practiced for hyperhidrosis, Raynaud's disease, and various psychiatric disorders. With the popularization of lobotomy in the 1940s, sympathectomy fell out of favor as a form of psychosurgery.
The endoscopic version of thoracic sympathectomy was pioneered by Goren Claes and Christer Drott in Sweden in the late 1980s. The development of endoscopic "minimally invasive" surgical techniques have decreased the recovery time from the surgery and increased its popularity. Today, ETS surgery is practiced in many countries throughout the world.
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| 関連記事 | 「lumbar」「sympathectomy」 |