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Published on: March 27, 2017
Six-year outcomes of a phase II study of human-tissue engineered blood vessels for peripheral arterial bypass
Piotr Gutowski1, Malgorzata Guziewicz2, Marek Ilzecki3
1Department of Vascular Surgery and Angiology, Pomeranian Medical University of Szczecin, Szczecin, Poland.
Insights
The human acellular vessel (HAV) shows promise as a durable bypass graft for peripheral artery disease (PAD). Six-year results indicate a 60% secondary patency rate, with no infections or rejections, suggesting HAV as a viable alternative for limb revascularization.
Area of Science:
- Vascular Surgery
- Biomaterials Science
- Regenerative Medicine
Background:
- Peripheral artery disease (PAD) significantly impacts lower extremity blood supply.
- Autologous grafts are often unavailable for femoropopliteal bypass surgery.
- Bioengineered vascular grafts are needed to address limitations of current treatment options.
Purpose of the Study:
- To evaluate the 6-year outcomes of the human acellular vessel (HAV) in patients undergoing femoropopliteal bypass surgery.
- To assess the safety and efficacy of HAV as a bypass conduit in advanced PAD.
- To determine the long-term patency and complication rates of HAV implantation.
Main Methods:
- Prospective, open-label, multicenter study of 20 patients with advanced PAD.
- Implantation of HAV for above-the-knee femoropopliteal bypass.
- Follow-up evaluation for up to 6 years (72 months), with mid-term analysis at the 6-year milestone.
- Kaplan-Meier analysis for patency rates, censoring for death.
Main Results:
- At 72 months, overall primary, primary assisted, and secondary patency rates were 44%, 45%, and 60%, respectively.
- No instances of HAV rejection or infection were reported.
- No patient required limb amputation; one patient experienced a pseudoaneurysm, and another required thrombectomy twice for graft occlusion.
Conclusions:
- The human acellular vessel (HAV) demonstrates potential as an infection-resistant, off-the-shelf alternative conduit for arterial bypass.
- HAV may facilitate remodeling into the recipient's own vessel, offering a durable solution for restoring lower extremity blood supply in PAD patients.
- Ongoing clinical trials are further investigating HAV for PAD, vascular trauma, and hemodialysis access.
Objective:
The human acellular vessel (HAV) was evaluated for surgical bypass in a phase II study. The primary results at 24 months after implantation have been reported, and the patients will be evaluated for ≤10 years.
Methods:
In the present report, we have described the 6-year results of a prospective, open-label, single-treatment arm, multicenter study. Patients with advanced peripheral artery disease (PAD) requiring above-the-knee femoropopliteal bypass surgery without available autologous graft options had undergone implantation with the HAV, a bioengineered human tissue replacement blood vessel. The patients who completed the 24-month primary portion of the study will be evaluated for ≤10 years after implantation. The present mid-term analysis was performed at the 6-year milestone (72 months) for patients followed up for 24 to 72 months.
Results:
HAVs were implanted in 20 patients at three sites in Poland. Seven patients had discontinued the study before completing the 2-year portion of the study: four after graft occlusion had occurred and three who had died of causes deemed unrelated to the conduit, with the HAV reported as functional at their last visit. The primary results at 24 months showed primary, primary assisted, and secondary patency rates of 58%, 58%, and 74%, respectively. One vessel had developed a pseudoaneurysm deemed possibly iatrogenic; no other signs of structural failure were reported. No rejections or infections of the HAV occurred, and no patient had required amputation of the implanted limb. Of the 20 patients, 13 had completed the primary portion of the study; however, 1 patient had died shortly after 24 months. Of the remaining 12 patients, 3 died of causes unrelated to the HAV. One patient had required thrombectomy twice, with secondary patency achieved. No other interventions were recorded between 24 and 72 months. At 72 months, five patients had a patent HAV, including four patients with primary patency. For the entire study population from day 1 to month 72, the overall primary, primary assisted, and secondary patency rate estimated using Kaplan-Meier analysis was 44%, 45%, and 60% respectively, with censoring for death. No patient had experienced rejection or infection of the HAV, and no patient had required amputation of the implanted limb.
Conclusions:
The infection-resistant, off-the-shelf HAV could provide a durable alternative conduit in the arterial circuit setting to restore the lower extremity blood supply in patients with PAD, with remodeling into the recipient's own vessel over time. The HAV is currently being evaluated in seven clinical trials to treat PAD, vascular trauma, and as a hemodialysis access conduit.
