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

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 space, 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."

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

The almost total absence of myelinated and amyelinated fibers following clip removal suggests that sympathectomy is NOT reversible

Ten days after clipping, all sympathetic chains displayed evident Wallerian degeneration. Twenty days after clipping, Wallerian degeneration of myelinated fibers was more widespread and also more striking. Thirty days after clipping, a very marked macrophagic reaction was visible, with multiple signs of phagocytosis of myelin debris. By 30 days post operation and 20 days after clip removal, a few residual myelin and amyelinated fibers were visible. These findings suggest that axon regeneration is not possible. CONCLUSIONS There are Wallerian degeneration and axon loss 10 days after clipping. The almost total absence of myelinated and amyelinated fibers following clip removal suggests that there was no nerve regeneration, and that therefore clipping cannot be considered a reversible technique.

Surg Endosc. 2012 May ;26 (5):1258-63  22083329 

Intense pain following sympathectomy, reduced inspiratory capacity

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://lib.bioinfo.pl/meid:154350/pmid

On a metabolic basis, 'autosympathectomy' influences neural and muscle structures and leads also to peripheral vasodilatation

Radiology of Peripheral Vascular Diseases: With 198 Tables

 edited by Eberhard Zeitler, Ernst Ammann

Springer, 2000 - Medical - 712 pages

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