The thyroid gland is located in the neck, and sits on top of the vocal nerves. Surgery involving the thyroid gland can cause vocal damage.
Other Neck Surgery
The vocal nerves are located in the neck and could be injured significantly while performing surgery on another structure in the neck.
When a spine surgeon operates on your cervical spine (neck), this may require an incision in the front of your neck which can cause vocal damage.
During chest surgery (heart, lung, esophagus) the breathing tube is placed between the vocal cords and may cause injury.
The vocal cords move due to input from two nerves. Many disease processes may result in weakness of one of these nerves, and produce symptoms.