Abstract: Objective To compare the effect of ablations with pulsed and continuous high-intensity focused ultrasound (HIFU)
on the target area containing large blood vessels in isolated perfused porcine liver. Methods An isolated perfused liver model
was established by perfusing the isolated porcine liver with autologous blood through the portal vein and hepatic artery using
an cardiopulmonary bypass machine. With B-mode ultrasound guidance, a blood vessel about 4 mm in diameter was selected,
and pulsed and continuous HIFU ablation at the same dose was delivered along the blood vessel at 3 mm to the vascular wall.
After the ablation, the damages of the blood vessels as the acoustic channel and the target area were inspected, and the tissues
at the interface of target volume and blood vessels were sampled for pathological examination. Results Neither pulsed nor
continuous HIFU caused noticeable injuries of the acoustic channel vessels, but the volume of necrotic tissues in the target area
differed significantly between the two groups (P<0.05). HE staining and vessel staining did not show any injuries of the blood
vessels in the pathway of ultrasound ablation in neither of the groups (P>0.05). Conclusions When the target area contains
large blood vessels in the pathway of ultrasound ablation, pulsed HIFU can have better therapeutic efficiency to effectively
induce tissue damages without affecting the blood vessels．