Can anyone help me with the following:

Laparoscopic takedown of gastrogastric fistula, partial gastrectomy with gastric plication....

If i need to use unlisted procedure codes, does anyone know of the open codes for these procedures, as when i write a letter to go with the claim, i will need to reference the 'open' codes.

Patient is s/p gastric bypass for morbid obesity w/severe gastritis and gerd.

Thanks for your help!