Oesophageal cooling with ice water does not reduce the incidence of oesophageal lesions complicating catheter ablation of atrial fibrillation: randomized controlled study.
OBJECTIVE
Atrial fibrillation (AF) ablation can result in oesophageal injuries that lead to atrio-oesophageal fistulae, a life-threatening complication. This study aimed to evaluate whether oesophageal cooling could prevent oesophageal lesions complicating AF ablation.


RESULTS
We randomly assigned 100 patients with drug-resistant AF to an oesophageal cooling group or a control group. In the oesophageal cooling group, we injected 5 mL of ice water into the oesophagus prior to radiofrequency (RF) energy delivery adjacent to the oesophagus. If the oesophageal temperature reached 42°C, the RF energy delivery was stopped, and the ice water injection was repeated. In the control group, oesophageal cooling was not applied. Oesophageal endoscopy was performed 1 day after the catheter ablation, and lesions were qualitatively assessed as mild, moderate, or severe. The numbers of ablation sites with an oesophageal temperature of >42°C were 1.7 ± 1.4 and 2.6 ± 1.7 in the oesophageal cooling group and the control group, respectively (P = 0.04), and the maximal oesophageal temperature at those sites was 43.0 ± 0.6 and 44.7 ± 0.9°C (P < 0.0001). Oesophageal lesions occurred almost equally between the oesophageal cooling group [10 of 50 patients (20%)] and the control group [11 of 50 patients (22%)]. However, the severity of the oesophageal lesions was slightly milder in the oesophageal cooling group (three moderate, seven mild) than in the control group (three severe, one moderate, seven mild).


CONCLUSIONS
Oesophageal cooling may alleviate the severity of oesophageal lesions but does not reduce the incidence of this complication under the specific protocol evaluated here.
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan dr.kuwahara@gmail.com.
Taishi
T
Kuwahara
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Atsushi
A
Takahashi
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Kenji
K
Okubo
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Katsumasa
K
Takagi
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Kazuya
K
Yamao
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Emiko
E
Nakashima
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Naohiko
N
Kawaguchi
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Masateru
M
Takigawa
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Yuji
Y
Watari
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Tomoko
T
Sugiyama
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Keita
K
Handa
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Shigeru
S
Kimura
Cardiovascular Center, Yokosuka Kyousai Hospital, 1-16, Yonegahama-dori, Yokosuka, Kanagawa 238-8558, Japan.
Hiroyuki
H
Hikita
Cardiology Division, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8576, Japan.
Akira
A
Sato
Cardiology Division, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki 305-8576, Japan.
Kazutaka
K
Aonuma
D001281:Atrial Fibrillation / Q000150:complications / Q000601:surgery* / Q000628:therapy*; D017115:Catheter Ablation / Q000009:adverse effects* / Q000379:methods*; D003131:Combined Modality Therapy / Q000379:methods; D004935:Esophageal Diseases / Q000209:etiology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D007053:Ice; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D007507:Therapeutic Irrigation / Q000379:methods; D016896:Treatment Outcome
D007053:Ice
Atrial fibrillation; Catheter ablation; Oesophageal complication; Oesophageal cooling; Oesophageal temperature monitoring