Balloon-Occluded Transarterial Chemoembolization for Hepatocellular Carcinoma: Technical Rationale, Current Evidence, and Future Directions.

Balloon-occluded transarterial chemoembolization (B-TACE) uses temporary microballoon occlusion to reduce distal arterial pressure and promote dense, selective deposition of chemoembolic material within the tumor and its drainage territory. Observational comparative studies and a meta-analysis suggest higher complete response and objective response rates than conventional TACE (C-TACE), especially in 3-5 cm tumors. However, randomized evidence and a proven survival advantage are lacking. Clinical benefit is therefore most plausible in carefully selected patients with preserved liver function, a limited tumor burden amenable to segmental treatment, and anatomy in which collateral inflow does not prevent a meaningful pressure reduction. Measurement of balloon-occluded arterial stump pressure may help characterize hemodynamics, but the proposed <64 mmHg threshold is not universally reproducible or routinely available. B-TACE has a broadly comparable overall safety profile to C-TACE, while non-target or excessive peripheral embolization can injure the peribiliary plexus and cause biloma or hepatic abscess. Future priorities include standardized technical endpoints, prospective randomized comparisons, validated selection criteria, imaging-based hemodynamic prediction, and rigorously designed combinations with systemic or other locoregional therapies.