Several reports have dealt with the alteration of antibody responses of spleen and lymph nodes following sympathectomy

http://www.ncbi.nlm.nih.gov/pubmed/8528891

Impairment of heart action following various methods of surgical denervation

A considerable variation in the distribution of fibres from the left sympathetic trunk to the right heart and from the right sympathetic trunk to the left side of the heart has also been shown (Randall et al., 1968a). However, the normal pattern is that large sympathetic nerves reach the base of the heart anteriorly and descend on either side of the main pulmonary artery. Nerves descending on the right of the pulmonary artery go to the atria and right ventricle. 

Interruption of afferent and efferent innervation of the heart also produces a response from circulatory and renal systems. 


Surgical cardiac denervation was carried out in 25 greyhounds and their responses to exercise, propranolol, and atropine were observed between one and three months afterwards. Our experiments confirm that a denervated heart shows delayed and diminished response to exercise and no response to atropine and propranolol.

Impairment of heart action following various methods of surgical denervation
T. J. OTTO' and P. C. CHEAH
The Nuffield Unit of Clinical Physiology, Department of Surgery, Royal Postgraduate Medical School, Ducane Road, London, W.12
Thorax(1970),25,199. 

Sympathectomy significantly alters vascular responses

Vascular responses to warming were studied in hemiplegic patients and after sympathectomy, using venous occlusion plethysmography of foot and leg. Comparisons were made with corresponding age groups. The pattern of response was essentially unchanged in hemiplegic patients, but was altered substantially where sympathetic pathways had been interrupted.

Vasomotor Responses in the Extremities of Subjects with Various Neurologic Lesions

I. Reflex Responses to Warming

1. WALTER REDISCH, M.D.; 
2. FRANCISCO T. TANGCO, M.D.; 
3. LOTHAR WERTHEIMER, M.D.;
4. ARTHUR J. LEWIS, M.D.; 
5. J. MURRAY STEELE, M.D.; 
6. Dorothy Andrews, B.A.,

http://circ.ahajournals.org/content/15/4/518.abstract

Sympathectomy involves division of adrenergic, cholinergic and sensory fibers which elaborate adrenergic substances during the process of regulating visceral function

G. SURGICAL SYMPATHECTOMY AND ADRENERGIC FUNCTIONPharmacol Rev March 1966 18:611-618;

Sympathectomy (ETS or ESB) can alleviate social phobia and common fears such as fear of flying, heights, open spaces or the darkness

Is sympathectomy the new lobotomy?

"ESB may also alleviate social phobia and common fears such as fear of flying, heights, open spaces, or the darkness. In addition, it can be used to decrease trembling of the body, hands, and voice, even stuttering. It may help in alcoholism or drug withdrawal, because these are often linked with social anxiety. 
Sympathetic block is a gentle and exact endoscopic procedure. It is performed as day surgery under light anesthesia." 
from the website of Dr T. Telaranta, Finnland, who performs sympathectomy for a variety of conditions.

http://www.sympatix.fi/?lang=en

Intense pain, reduced inspiratory capacity following sympathectomy

Intrapleural analgesia after endoscopic thoracic sympathectomy.

Patrícia Gomes da Silva, Daniele Cristina Cataneo, Fernanda Leite, Erica Nishida Hasimoto, Guilherme Antonio Moreira de Barros

Postgraduate Program in Anesthesiology, Botucatu School of Medicine, UNESP, Bauru, SP, Brazil.

PURPOSE To compare analgesia traditionally used for thoracic sympathectomy to intrapleural ropivacaine injection in two different doses. METHODS Twenty-four patients were divided into three similar groups, and all of them received intravenous dipyrone. Group A received intravenous tramadol and intrapleural injection of saline solution. Group B received intrapleural injection of 0.33% ropivacaine, and Group C 0.5% ropivacaine. The following aspects were analyzed: inspiratory capacity, respiratory rate and pain. Pain was evaluated in the immediate postoperative period by means of the visual analog scale and over a one-week period. RESULTS In Groups A and B, reduced inspiratory capacity was observed in the postoperative period. In the first postoperative 12 hours, only 12.5% of the patients in Groups B and C showed intense pain as compared to 25% in Group A. In the subsequent week, only one patient in Group A showed mild pain while the remainder reported intense pain. In Group B, half of the patients showed intense pain, and in Group C, only one presented intense pain. CONCLUSION Intrapleural analgesia with ropivacaine resulted in less pain in the late postoperative period with better analgesic outcomes in higher doses, providing a better ventilatory pattern.

http://www.ncbi.nlm.nih.gov/pubmed/22042116

Brachial plexopathy is another well recognised but not much publicised side-effect of sympathectomy

Brachial plexus dysfunction (brachial plexopathy) is a form of peripheral neuropathy. It occurs when there is damage to the brachial plexus, an area on each side of the neck where nerve roots from the spinal cord split into each arm's nerves.

Damage to the brachial plexus is usually related to direct injury to the nerve, stretching injuries (including birth trauma), pressure from tumors in the area (especially from lung tumors), or damage that results from radiation therapy.

Brachial plexus dysfunction may also be associated with:

• Birth defects that put pressure on the neck area
• Exposure to toxins, chemicals, or drugs
• General anesthesia, used during surgery
• Inflammatory conditions, such as those due to a virus or immune system problem

In some cases, no cause can be identified.

Symptoms

• Numbness of the shoulder, arm, or hand
• Shoulder pain
• Tingling, burning, pain, or abnormal sensations (location depends on the area injured)
• Weakness of the shoulder, arm, hand, or wrist

http://www.nlm.nih.gov/medlineplus/ency/article/001418.htm