Enhancing Liver Volume for Safer Hepatic Surgery: Portal and Hepatic Vein Embolization

Overview

Portal vein embolization (PVE) is a well-established technique to induce hypertrophy of the future liver remnant (FLR) before major hepatectomy, reducing postoperative liver failure risk. However, PVE alone may be insufficient or slow in some patients, leading to the development of combined portal and hepatic vein embolization (PVE/HVE) to accelerate and enhance FLR growth.

Background

Major hepatic resections require an adequate future liver remnant (FLR) volume to prevent postoperative liver failure. Portal vein embolization (PVE) has been widely adopted to induce hypertrophy of the FLR by redirecting portal blood flow. Early techniques like portal vein ligation (PVL) were effective but invasive. PVE offers a minimally invasive alternative with comparable hypertrophy and improved patient recovery. Despite its success, approximately 30–40% of patients undergoing PVE for colorectal liver metastases fail to achieve sufficient hypertrophy or experience disease progression during the waiting period. To overcome these limitations, simultaneous portal and hepatic vein embolization (PVE/HVE) has emerged as a promising approach to accelerate FLR hypertrophy.

Data Highlights

Key Findings

• PVE is an effective, minimally invasive method to induce FLR hypertrophy and improve outcomes in major hepatectomy.
• Approximately 30–40% of patients with colorectal liver metastases do not achieve adequate hypertrophy or experience disease progression after PVE.
• Combined portal and hepatic vein embolization (PVE/HVE) shows promise in accelerating and enhancing FLR hypertrophy compared to PVE alone.
• Early portal vein ligation (PVL) was effective but more invasive and associated with increased inflammation and scarring.
• Embolic materials such as N-butyl cyanoacrylate (NBCA) mixed with Lipiodol provide rapid and permanent occlusion, facilitating hypertrophy but require careful technique to avoid complications.
• Randomized trials like BestFLR highlight the superiority of NBCA over other embolic agents for PVE.

Clinical Implications

Clinicians should consider PVE as the standard preoperative approach to increase FLR volume and reduce postoperative liver failure risk in major hepatectomy candidates. For patients at risk of insufficient hypertrophy or disease progression, combined PVE/HVE may offer a faster and more effective alternative. Selection of embolic materials, such as NBCA, should be tailored to optimize occlusion efficacy while minimizing complications.

Conclusion

PVE remains a cornerstone technique to enhance FLR and improve surgical safety in hepatic resections. Emerging combined embolization strategies and optimized embolic agents hold promise to further improve outcomes by accelerating liver hypertrophy and expanding resectability.

References

1. Rous and Larimore 1920 -- Portal vein ligation induces contralateral liver hypertrophy
2. Honjo et al. 1975 -- Portal vein ligation in unresectable liver carcinoma
3. Kinoshita et al. 1986 -- Introduction of percutaneous portal vein embolization
4. Makuuchi et al. 1990 -- Standardization of PVE before major hepatectomy
5. Vauthey et al. -- Median 12% FLR increase after PVE
6. Azoulay et al. -- FLR hypertrophy from 26% to 37% post-PVE
7. BestFLR trial -- NBCA superiority in PVE embolic agents