Namias, Nicholas

Importance Vascular injuries require urgent repair to minimize loss of limb and life. Standard revascularization relies on autologous vein or synthetic grafts, but alternative options are needed when adequate vein is not feasible and when clinical conditions preclude safe use of synthetic materials. Objective To evaluate the performance of the acellular tissue engineered vessel (ATEV) in the repair of extremity arterial injuries. Design, Setting, and Participants Two open-label, single-arm, nonrandomized clinical trials, including 1 prospective civilian study (CLN-PRO-V005 [V005]) and 1 retrospective observational study in a war zone (CLN-PRO-V017 [V017]), were conducted from September 2018 to January 2024 (follow-up ongoing) at 19 level 1 trauma centers in the US and Israel and 5 frontline hospitals in Ukraine. Patients had vascular injury, no autologous vein available for emergent revascularization, and risk factors for wound infection. Data include the subset of patients with extremity injuries and were analyzed from September 2023 to January 2024. Intervention The ATEV is a bioengineered vascular conduit grown from human vascular cells, available off the shelf, and implantable without immunosuppression. Main Outcomes and Measures Primary patency at day 30 was the primary outcome. Secondary outcomes included limb salvage, graft infection, and patient survival. A systematic literature review identified synthetic graft benchmarks in the treatment of arterial trauma for the same end points. Results The arterial extremity injury subset included 51 of 69 participants in V005 and 16 of 17 participants in V017. The majority were male (V005, 38 [74.5%]; V017, 16 [100%]), the mean (SD) ages were similar (V005, 33.5 [13.6] years; V017, 34.2 [9.0] years), and the mean (SD) Injury Severity Scores were similar (V005, 20.8 [10.5]; V017, 20.1 [18.9]). Penetrating injuries dominated (V005, 29 patients [56.9%]; V017, 14 patients [87.5%]). At day 30 for the V005 and V017 trials, respectively, ATEV primary patency was 84.3% (95% CI, 72.0%-91.8%) and 93.8% (95% CI, 71.7%-98.9%); secondary patency was 90.2% (95% CI, 79.0%-95.7%) and 93.8% (95% CI, 71.7%-98.9%); amputation rate was 9.8% (95% CI, 4.3%-21.0%) and 0% (95% CI, 0.0%-19.4%); ATEV infection rate was 2.0% (95% CI, 0.4%-10.3%) and 0% (95% CI, 0.0%-19.4%); and death rate was 5.9% (95% CI, 2.0%-15.9%) and 0% (95% CI, 0.0%-19.4%) (no deaths attributed to the ATEV at day 30). Day 30 synthetic graft benchmarks were as follows: secondary patency, 78.9%; amputation, 24.3%; infection, 8.4%; and death, 3.4%. Conclusions and Relevance Results of analysis in the subset of patients with vascular extremity injuries in 2 single-arm trials in civilian and real-world military settings suggest that the ATEV provides benefits in terms of patency, limb salvage, and infection resistance. Comparing ATEV outcomes with synthetic graft benchmarks demonstrated improved outcomes in the treatment of acute vascular injuries of the extremities. The analyses reported herein are limited to the subset of 67 patients with vascular extremity injuries out of 86 patients enrolled in 2 trials and excluded 19 patients with iatrogenic and torso injuries. Had these 19 patients been included in these analyses, the efficacy and safety findings could have been attenuated. Trial Registration ClinicalTrials.gov Identifiers: NCT03005418 , NCT05873959