No anesthesia is risk-free, just as no surgery is risk-free.

General Considerations for Surgery

Undergoing any type of surgery involves risks. General considerations for surgery include infection, swelling, delayed healing caused by smoking or vascular conditions, bruising, excessive bleeding, scars, numbness, and life-threatening blood clots.

http://www.surgery.org/consumers/patient-safety/surgical-risks-overview

http://www.mayoclinic.org/tests-procedures/anesthesia/basics/risks/PRC-20014786