A new study found that children who wet the bed who also have sleep apnea may stop having accidents if their tonsils are removed. Out of 400+ kids, nearly half stopped wetting the bed after tonsillectomy. You can read more about it here.
Tonsillectomy is an invasive procedure, and should not be the primary treatment for bedwetting. But it may be worth a consultation with your Pediatrician or an Ear, Nose and Throat doctor (an Otolaryngologist) to see if it is something to consider for your child.