Objectives: To evaluate the therapeutic efficacy of and vascular complications associated with percutaneous cryoablation for the treatment of perivascular HCC.

Methods: Between August 2015 and September 2017, 58 consecutive patients (48 men, 10 women; mean age, 61.1 years; age range, 44-84 years) who underwent percutaneous cryoablation were included. All patients had a single perivascular HCC (mean size, 1.3 cm; Barcelona clinic liver cancer-stage 0 or A) that was in contact with hepatic vessels, ≥ 3 mm or larger in axial diameter. Local tumour progression (LTP) was estimated by the Kaplan-Meier method. In addition, several procedure-related vascular complications were evaluated immediately after treatment and during follow-up CT: peritumoral vessel thrombosis; infarction; aggressive intrasegmental recurrence (AIR) (the simultaneous development of ≥ 3 nodular or infiltrative tumours). The follow-up CT was performed in all patients 1 month after the procedure, and every 3 months thereafter.

Results: The median follow-up period was 22 months (range, 3-29 months). The technical success rate of cryoablation was 96.6% (56/58). The 1- and 2-year cumulative LTP rates were 3.6% and 14.6%, respectively. Although peritumoral vessel thrombosis occurred in 6.9% of cases (4/58), no cases of hepatic infarction were observed and AIR did not develop during follow-up. Half of the thombi in the peritumoral vessels immediately after cryoablation disappeared on follow-up CT images.

Conclusion: Cryoablation could be an effective tool for the treatment of perivascular HCC with a very low risk of vascular complications.

Key points: • Cryoablation allowed a high technical success rate for perivascular HCC. • Only 6.9% developed peritumoral vessel thrombosis without major vascular complications like infarction. • Two-year cumulative LTP rate was 14.6%, without aggressive tumour recurrence on follow-up.