Potential of a no-touch pincer ablation procedure that uses a multipolar radiofrequency ablation system to prevent intrasubsegmental recurrence of small and single hepatocellular carcinomas.

Objective: The aim of this study was to clarify the usefulness of a no-touch pincer ablation procedure that uses bipolar electrodes to prevent intrasubsegmental tumor recurrence after radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC).
Methods: We studied 303 consecutive patients with HCC (single nodule and tumor diameter ≤30 mm) who received RFA between January 2005 and April 2015; 268 patients received touch ablation using a monopolar or bipolar RFA device, and 35 received no-touch ablation using a bipolar RFA device. The pretreatment arterial and portal phase dynamic computed tomography or magnetic resonance images were classified into four enhancement patterns. Type 1 and Type 2 are homogeneous enhancement patterns without or with increased arterial blood flow, respectively. Type 3 is a heterogeneous enhancement pattern with a septum-like structure, and Type 4 is an irregularly shaped ring structure enhancement pattern.
Results: With regard to intrasubsegmental tumor recurrence, among the 268 patients who underwent the touch ablation procedure, tumors recurred in 52 (19.4%) patients, and among the 35 patients who underwent the no-touch ablation procedure, tumors recurred in one (2.9%) patient. Cumulative intrasubsegmental tumor recurrence rates tended to be higher with touch ablation (P = 0.083). Multivariate Cox proportional hazards analysis revealed that ablation procedure (touch ablation, hazard ratio [HR] 10.32, P = 0.032), type of enhancement pattern (Type 3, HR 3.05, P = 0.006; and Type 4, HR 8.87, P < 0.001) and serum des-γ-carboxyprothrombin level (≥100 AU/L; HR 2.73, P = 0.035) were significant predictors for intrasubsegmental recurrence.
Conclusion: The no-touch pincer ablation procedure has the potential to prevent intrasubsegmental recurrence after RFA for patients with HCC.
(© 2016 The Japan Society of Hepatology.)