Every surgery and every surgeon is slightly different so it's always best to ask your surgeon this very question. Surgery for de Quervain disease is usually done to free up two tendons in the wrist and thumb area.
The abductor pollicis longus (APL) and the extensor pollicis brevis (EPB) can become inflammed and scarred down with fibrotic tissue in de Quervain disease. The surgeon will make an incision in the skin to get to the tendons. Each tendon will be carefully cut loose from anything keeping it from moving smoothly and freely.
If there is nerve pain or numbness and tingling, the surgeon might cut or apply heat to the nerve. This will stop the nerve from sending painful messages to the brain. It won't affect the muscle's power or function.