OBJECTIVETo observe the effect of targeted argon-helium cryoablation on portal region of the liver in dogs by observing the pathological changes in the first-order branches of the Glisson ductal system.

METHODSTwelve healthy dogs underwent percutaneous targeted argon-helium cryoablation of the liver and sacrificed at 3 and 28 days after the cryoablation to observe the pathological changes in target area for cryoablation and the first-order branches of the Glisson ductal system.

RESULTSNo obvious damage was not found in the vascular wall of the portal vein by gross or microscopic observation, but the liver tissue in the vicinity of the blood vessels showed total necrosis. In spite of the injuries of different degrees in the first-order bile duct system after argon-helium cryoablation, no severe damages such as perforation or full-thickness necrosis occurred in bile duct wall, and most of the injuries were temporary and reversible. The size of the ablated area on day 28 was significantly reduced as compared with that on day 3 following the cryoablation (P<0.05). In the acute stage after the cryoablation (1-3 days), ALT and AST levels increased significantly in (P<0.05) but recovered 1-4 weeks later (P>0.05). The cryoablated area was basically consistent with the pathological area that underwent necrosis (P>0.05).

CONCLUSIONTargeted argon-helium cryoablation can cause total destruction of the liver tissue around the blood vessel without damaging the vascular walls of the portal vein. Argon-helium cryoablation induces relatively minor injuries to the bile duct of hepatic portal section and does not obviously damage the liver function, and the scope of tissue necrosis can be estimated according to the size of frozen area observed. Argon-helium cryoablation is a safe and minimally invasive operation with reliable therapeutic effect.