Safety and efficacy of combined portal and hepatic vein embolisation in patients with colorectal liver metastases (DRAGON1): a multicentre, single-arm clinical trial

Background: Major liver resection is often required for complete clearance of colorectal liver metastases (CRLM). Patients with insufficient future liver remnant (FLR) volume/function are at high risk of post-hepatectomy liver failure (PHLF) and require FLR hypertrophy-inducing procedures to enable safe resection. The most recent variant of these procedures is combined portal and hepatic vein embolization (PVE/HVE). The DRAGON 1 trial evaluates the safety and efficacy of PVE/HVE, while assessing recruitment potential for the DRAGON 2 randomized trial. Methods: DRAGON 1 is a prospective, single-arm, international, multicenter trial. Patients with upfront unresectable CRLM due to a small FLR were included. The primary outcome was the ability of centers to recruit three patients and perform PVE/HVE and liver resection without 90-day mortality. Secondary outcomes included recruitment capacity, PVE/HVE technical details, FLR volume changes, complications, and resection rates. The study is registered at ClinicalTrials.gov, identifier: NCT04272931. Findings: In total, 102 patients were included from 43 centers. Twenty-four centers (24/43 = 56%) recruited three or more patients, and 20 centers (20/43 = 47%) achieved this without 90-day mortality. Of 96 patients undergoing PVE/HVE, no post-embolization mortality occurred, though major complications were reported in two patients. Resection was completed in 86 patients (86/96 = 90%), with seven patients (7/86 = 8%) dying within 90 days. PHLF grade B/C (International Study Group of Liver Surgery criteria) occurred in 19 patients (19/86 = 22%). Interpretation: DRAGON 1 demonstrates that PVE/HVE is safe, with no embolization-related mortality, low morbidity, and high resection rates in upfront unresectable CRLM. Funding: The Dutch Cancer Society, National Institute for Health and Care Research UK, Maastricht UMC+, Abbott Laboratories and Guerbet.