Dose-dependent depth of tissue injury with carbon dioxide cryotherapy in porcine GI tract.
BACKGROUND
Cryotherapy is a method of endoscopic mucosal ablation that involves delivery of a cryogen to result in tissue destruction by extreme low temperature. Its effects are influenced by the dosage of cryogen and thawing of ice. There are limited data on the tissue effects of multiple freeze and thaw cycles of carbon dioxide (CO(2)) cryotherapy on GI tissues.


OBJECTIVE
To investigate the extent of tissue injury due to escalating doses of CO(2) cryotherapy on the esophagus, stomach, and colon of pigs.


METHODS
Animal experiment.


METHODS
Varying doses of CO(2) cryotherapy with increasing number of freeze-thaw cycles were applied to each site. The animals were allowed to survive for 48 hours.


METHODS
Depth of tissue injury assessed in blinded fashion by varying doses of cryotherapy on a defined area of porcine esophagus, stomach, and colon.


RESULTS
There was a dose-dependent relationship of CO(2) cryogen and depth of injury (P = .0001 and P = .002, respectively). In the stomach, the dose-response relationship was significant (P = .007), but the average grades of injury across the various doses were lower when compared with the esophagus at comparable cryogen doses (P = .0004). The estimated depth of tissue injury from the mucosal surface in the porcine esophagus and colon tissue ranged from 1.2 to 2.5 mm and 1.3 to 2.5 mm, respectively.


CONCLUSIONS
The study was performed in a normal porcine model.


CONCLUSIONS
There was a dose-dependent relationship between the dose of CO(2) cryotherapy and the depth of tissue injury in the porcine esophagus, stomach, and colon.
Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Johns Hopkins Hospital, Baltimore, Maryland, USA. eshin3@jhmi.edu
Eun Ji
EJ
Shin
Stuart K
SK
Amateau
Yongsik
Y
Kim
Kathleen L
KL
Gabrielson
Elizabeth A
EA
Montgomery
Mouen A
MA
Khashab
Vinay
V
Chandrasekhara
Daniil
D
Rolshud
Samuel A
SA
Giday
Marcia Irene
MI
Canto
D055011:Ablation Techniques / Q000379:methods*; D000818:Animals; D002245:Carbon Dioxide / Q000008:administration & dosage*; D016009:Chi-Square Distribution; D003106:Colon / Q000601:surgery; D003452:Cryosurgery; D004947:Esophagus / Q000601:surgery; D005753:Gastric Mucosa / Q000473:pathology / Q000601:surgery*; D007413:Intestinal Mucosa / Q000473:pathology / Q000601:surgery*; D018709:Statistics, Nonparametric; D013270:Stomach / Q000601:surgery; D013552:Swine
D002245:Carbon Dioxide