Esophageal luminal temperature measurement underestimates esophageal tissue temperature during radiofrequency ablation within the canine left atrium: comparison between 8 mm tip and open irrigation catheters.
BACKGROUND
Evaluation of luminal temperature during left atrial ablation is used clinically; however, luminal temperature does not necessarily reflect temperature within the esophageal wall and poses a risk of atrioesophageal fistula. This animal study evaluates luminal esophageal temperature and its relation to the temperature of the external esophageal tissue during left atrial lesions using the 8 mm solid tip and the open irrigated tip catheters (OIC).


RESULTS
A thermocouple was secured to the external surface of the esophagus at the level of the left atrium of the dogs. Luminal esophageal temperature was measured using a standard temperature probe. In four randomized dogs, lesions were placed using an 8 mm solid tip ablation catheter. In six randomized dogs, lesions were placed using the 3.5 mm OIC. The average peak esophageal tissue temperature when using the OIC was significantly higher than that of the 8 mm tip catheter (88.6 degrees C +/- 15.0 degrees C vs. 62.3 degrees C +/- 12.5 degrees C, P < 0.05). Both OIC and 8 mm tip catheter had significantly higher peak tissue temperatures than luminal temperatures (OIC: 88.6 degrees C +/- 15.0 degrees C vs 39.7 degrees C +/- 0.82 degrees C, P < 0.05) (8 mm: 62.3 degrees C +/- 12.5 degrees C vs 39.0 +/- 0.5 degrees C, P < 0.05). Both catheters achieved peak temperatures faster in the tissue as compared to the lumen of the esophagus, although the tissue temperature peaked significantly faster for the OIC (OIC: 25 seconds vs 90 seconds, P < 0.05) (8 mm: 63 seconds vs 105 seconds, P < 0.05).


CONCLUSIONS
Despite the significant difference in actual tissue temperatures, no significant difference was observed in luminal temperatures between the OIC and 8 mm tip catheter.
Cummings
Jennifer E
JE
Department of Cardiovascular Medicine, Section of Electrophysiology and Pacing, Cleveland Clinic, Cleveland, Ohio, USA. cumminj@ccf.org
Barrett
Conor D
CD
Litwak
Kenneth N
KN
DI Biase
Luigi
L
Chowdhury
Punam
P
Oh
Seil
S
Ching
Chi Keong
CK
Saliba
Walid I
WI
Schweikert
Robert A
RA
Burkhardt
J David
JD
DE Marco
Shari
S
Armaganijan
Luciana
L
Natale
Andrea
A
D000818:Animals; D001281:Atrial Fibrillation / Q000503:physiopathology / Q000601:surgery*; D001831:Body Temperature / Q000502:physiology*; D017115:Catheter Ablation / Q000379:methods*; D004195:Disease Models, Animal; D004285:Dogs; D004947:Esophagus / Q000503:physiopathology*; D005500:Follow-Up Studies; D016343:Monitoring, Intraoperative / Q000379:methods*; D015203:Reproducibility of Results; D007507:Therapeutic Irrigation / Q000295:instrumentation*; D013821:Thermometers