Experimental bile duct protection by intraductal cooling during radiofrequency ablation.
BACKGROUND
The use of radiofrequency ablation (RFA) for liver tumours is limited by the proximity of large bile ducts to the targeted lesion. The aim of this randomized study was to evaluate intraductal cooling as a mean of protecting the bile ducts during RFA.


METHODS
Twelve pigs underwent RFA adjacent to the right bile duct. After placement of an intraductal cooling catheter and a RFA probe, pigs were randomized to cooling or no cooling. Intraductal temperature was measured in all animals. The bile ducts were assessed by magnetic resonance imaging (MRI) and cholangiography 1 and 28 days after the procedure.


RESULTS
Intraductal cooling abolished the increase of intraductal temperature seen in the absence of cooling. Concurrent cholangiography and MRI showed a biliary lesion in one of six pigs subjected to intraductal cooling and in five of six without cooling (P = 0.040). The biliary injuries were barely visible by MRI on day 1 but were clearly visible on day 28.


CONCLUSIONS
Intraductal cooling can prevent biliary injury induced by RFA. The exact parameters for intraductal cooling require further investigation to establish the best compromise between bile duct protection and complete ablation of surrounding tissue.
Stippel
D L
DL
Department of Visceral and Vascular Surgery, University of Cologne, Germany. Dirk.Stippel@uni-koeln.de
Bangard
C
C
Kasper
H U
HU
Fischer
J H
JH
Hölscher
A H
AH
Gossmann
A
A
D000818:Animals; D001652:Bile Ducts / Q000293:injuries*; D017115:Catheter Ablation / Q000009:adverse effects*; D049448:Cholangiopancreatography, Magnetic Resonance / Q000379:methods; D007036:Hypothermia, Induced / Q000379:methods*; D008113:Liver Neoplasms / Q000601:surgery*; D008279:Magnetic Resonance Imaging / Q000379:methods; D010865:Pilot Projects; D011897:Random Allocation; D013552:Swine