Patients who undergo sympathotomy for hyperhidrosis will commonly report "clinically bothersome" compensatory hyperhidrosis.

J Thorac Cardiovasc Surg. 2014 Apr;147(4):1160-1163.e1. doi: 10.1016/j.jtcvs.2013.12.016. Epub 2014 Jan 2.

Sympathectomy causes wall thinning, elongation, convolution, and aneurysm formation

"Sympathectomy causes basilar artery enlargment, which is beneficial for maintaining cerebral blood flow; however, it also causes wall thinning, elongation, convolution, and aneurysm formation, which may be hazardous in stenoocclusive carotid artery disease. Sympathectomy can prevent new vessel formation and hyperthyrophic changes at the posterior circulation. Neovascularisation is not detected adequately in sympathectomised animals."



Acta Neurochirurgica156.5 (May 2014): 963-9.