Future liver remnant hypertrophy and postoperative outcomes: a retrospective comparison between segmental and main right portal vein embolization.

Objective: To assess the efficacy of segmental right portal vein embolization (SRPVE) versus main right portal vein embolization (MRPVE) in preoperative preparation for major hepatectomy.

Methods: This retrospective single-center study included 220 consecutive patients who underwent portal vein embolization (PVE) before (extended) right hemihepatectomy between January 2014 and June 2021. Seventy-one patients underwent selective segmental embolization (SRPVE) and 149 patients underwent MRPVE. Volumetric analysis was conducted before PVE and before surgery. Key endpoints included evaluation of future liver remnant (FLR) hypertrophy, intraoperative complexity, and postoperative complications, technical success, clinical success, complications (Clavien-Dindo and CIRSE classifications), as well as evaluation of different factors which may influence hypertrophy of the FLR.

Results: Technical success rate was 100% in the SRPVE group and 99.3% in the MRPVE group (p = 0.15). Clinical success rate was comparable between both techniques, measuring 95.8% in the SRPVE group and 95.3% in the MRPVE group (p = 0.18). Absolute hypertrophy (FLRabh) of the FLR was comparable between both techniques, measuring 47.15% in the SRPVE group and 40.78% in the MRPVE group (p = 0.54). Complication rates did not differ significantly (p = 0.12). Partial thrombosis involving the left portal vein, main portal vein, or mesentericosplenic region was observed in 2.8% of the patients in the SRPVE group vs 3.4% in the MRPVE group (p = 0.95). CIRSE Class II-VI complications were slightly higher in the MRPVE group (10.7% vs 9.8%, p = 0.82). Postoperative complications with Clavien-Dindo class ≥ IIIa occurred in 10.1% % in the MRPVE group vs 9.9% the SRPVE group (p = 0.92). Liver cirrhosis had a significant negative correlation with sFLR % increase following PVE (r = -0.54; p = 0.027). Neoadjuvant chemotherapy was also associated with reduced FLR hypertrophy following PVE, with a median sFLR% change of 63.8% (IQR: 60.8% - 75.2%) in patients who received neoadjuvant chemotherapy (n = 66 patients, 30%) compared to 82.6% (IQR: 77.4% - 84.2%) in those without chemotherapy (n = 154 patients, 70%).

Conclusion: Selective segmental right portal vein embolization, sparing the main right portal vein, offers a safe and effective alternative to MRPVE, achieving comparable FLR hypertrophy while potentially simplifying intraoperative procedures and reducing postprocedural complications. Future research should focus on conducting large, prospective, multicenter trials to further compare the long-term outcomes of this technique, particularly with regard to liver regeneration, postoperative liver function, complications and overall survival.