Abstract / Summary
Background Portal vein embolization (PVE) is routinely used before major hepatectomy to induce hypertrophy of the future liver remnant (FLR) and reduce post-hepatectomy liver failure. Conventional PVE relies on permanent embolic agents, resulting in irreversible portal occlusion, which may be associated with complications and may limit subsequent therapeutic options in patients who do not ultimately undergo resection. Whether transient portal deprivation alone can induce clinically relevant liver regeneration remains unknown. We evaluated the efficacy and safety of temporary selective PVE using an absorbable gelatin agent. Methods EMBORES was a multicenter prospective single-arm phase II trial conducted in six French hepatobiliary centers. Between May 3, 2018, and May 3, 2021, adult patients requiring major hepatectomy and preoperative PVE were included. Selective portal branches were embolized using powdered absorbable gelatin sponge. The primary endpoint was FLR hypertrophy assessed by computed tomography (CT) volumetry 4–6 weeks after PVE. Secondary endpoints included feasibility, morbidity, portal vein recanalization, and surgical outcomes. This trial is registered with ClinicalTrials.gov, NCT02945059. Findings 34 patients were enrolled and 32 underwent temporary PVE. Mean age was 63.4 years (standard deviation [SD] 8.9), and colorectal liver metastases accounted for 18 (56%) of 32 indications. Technical success was achieved in all patients. One major complication occurred (1 [3.1%] of 32 patients), while liver function remained preserved. Complete and partial portal vein recanalization were observed in 17 (53%) and 9 (28%) of 32 patients, respectively. Mean FLR volume increased from 580 (SD 169) mL to 690 (SD 188) mL, corresponding to a mean hypertrophy ratio of 9.5% (SD 10.2). Five patients required repeat embolization using a permanent agent because of insufficient hypertrophy. Overall, 23 (71.8%) of 32 patients underwent major hepatectomy, with no postoperative mortality. Interpretation Temporary PVE using an absorbable embolic agent is feasible, safe, and capable of inducing clinically meaningful liver hypertrophy before major hepatectomy, supporting the concept that transient portal vein occlusion may be sufficient to stimulate liver regeneration in selected patients. Funding The EMBORES study was funded by the French Ministry of Health through a national hospital clinical research program grant awarded in 2015 (Programme Hospitalier de Recherche Clinique National, PHRC-15-15-0201).