Sometimes the doctor will just disconnect the wire, leave it in and put in another one. It all depends on each individual case and the extent of the fracture.
If you do need a lead replaced make sure that it is an experienced surgeon doing the procedure.
Do you have a defective lead that is making you worry?
Actually, it's my father. His lead fractured and they're taking it out and replacing it on Tuesday. The doctor said that it's a small risk, but there will be a team of surgeons there in case they tear the vein or heart going through the scar tissue or pullling it out. For some reason, they said my father is a greater risk. We recently moved to Charlotte, NC and the doctor only does diffibrillators so I hope he's good!
It sounds like your father is in good hands. I'm sure everything will be fine and it's good they are prepared in case there is a problem.
Will a send a prayer your way.