Morphologic and functional effects of esophageal cryotherapy.

With advances in equipment design, cryotherapy has been applied increasingly in the management of various integumentary disorders. Recently, endobronchial cryotherapy has been utilized in the treatment of acquired tracheal strictures. To evaluate the effects of cryotherapy upon the esophagus, we cooled the distal esophagus of 12 cats to -70 degrees to -80 degrees C. for 2 minutes with a specially constructed cryoprobe. The animals were put to death in pairs 90 minutes, 4 days, 10 days, 14 days, 28 days, and 42 days following cryotherapy. Immediately prior to sacrifice, all animals were studied with esophageal cinefluoroscopy and esophageal manometrics. All animals tolerated this degree of cryotherapy and gained weight on an ad libitum diet. Manometric studies demonstrated diminished amplitude of peristalsis immediately following cryotherapy, but prompt return to a normal manometric pattern. There was no evidence of esophageal dysfunction on esophageal cinefluoroscopy. Morphologic examination demonstrated superficial ulceration between 4 and 10 days following cryotherapy, with subsequent healing. The esophagus in animals put to death 28 and 42 days following cryotherapy appeared histologically normal. These studies demonstrate the safety of cryotherapy to -70 to -80 degrees C. upon the esophageal wall and suggest investigation of the usefulness of this modality in the treatment of local esophageal webs and strictures.