Surgeons operating on a patient

Enrolling clinical trials: ZFEN+ stent graft

  • June 9, 2025
Headshot of Grace J. Wang, MD, MSCE, FACS

The Division of Vascular Surgery and Endovascular Therapy at Penn Medicine is participating in the Zenith® Fenestrated+ (ZFEN+) endovascular graft clinical study (Cook Medical, Bloomington, IN).

The study (NCT04875429) is currently enrolling at Penn Medicine under the direction of principal investigator Grace J. Wang, MD, MSCE, FACS.

Dr. Wang is the Vascular Director of the Penn Aorta Center, a comprehensive program dedicated to advancing aortic care by leveraging access to the newest trial devices, as well as ensuring optimized outcomes by utilizing national quality registries.

The ZFEN+ Pivotal Trial is an investigational, prospective, international, multicenter, non-randomized clinical study assessing the safety and effectiveness of the ZFEN+ graft in combination with the BeGraft Balloon-Expandable FEVAR Bridging Stent Graft System (BeGraft) and the Universal Distal Body 2.0 Graft (Unibody2).

The study will include patients with one or more extent IV thoracoabdominal (TAAA), pararenal, or juxtarenal aortic aneurysms. The ZFEN+ is based upon the commercially available Zenith Fenestrated AAA Endovascular Graft, but extends the potential of aneurysmal disease that can be treated endovascularly to include patients with more complex aortic disease, with up to 5 fenestrations incorporated.

The primary safety endpoint of the ZFEN+ study is a composite measure of device technical success and procedural safety within 30 days. The primary effectiveness endpoint is a composite measure of freedom from aneurysm-related mortality and clinically significant reintervention through 12 months post-procedure.

Background

Pararenal aortic aneurysms occur in the aorta below or adjacent to the kidneys and may involve the renal arteries, but do not extend above them to the visceral arteries. Juxtarenal abdominal aortic aneurysms involve the infrarenal abdominal aorta adjacent to (or including) the lower margin of the renal arteries.

Standard of care open surgical repair of pararenal or juxtarenal AAAs is complicated by their proximity to the renal and visceral arteries. Renal failure is a leading cause of postoperative morbidity in these surgeries, particularly among patients with preoperative renal insufficiency.

Developed as an alternative to open surgery, the Zenith Fenestrated AAA Endovascular Graft (ZFEN) is currently the only commercially available fenestrated stent graft available in the United States. The ZFEN is approved for both juxtarenal and pararenal aneurysms, and a substantial body of evidence exists for its safety and efficacy in the former. However, ZFEN has design limitations (three fenestrations and a single scallop only, among other deficits) that limit its application in pararenal aneurysms, aneurysms involving the renal arteries, and extent IV TAAAs.

These impediments (which are estimated to exclude two-thirds of complex AAAs) inspired the design of the investigational ZFEN+ endovascular graft.

ZFEN+ design

The ZFEN+ study has the aim of expanding the graft’s indications to aneurysms extending >2 cm above the celiac axis, and to broadening the indications to include pararenal aneurysms and TAAAs.

The re-design includes up to five reinforced fenestrations (or four fenestrations and one scallop) and a lower-profile woven polyester fabric. Fenestrations are available in small and large sizes (up to 0.8 cm) and are reinforced and strut-free (Endovascular Today, 2021).

The study will combine the ZFEN+ graft with the BeGraft Balloon-Expandable FEVAR Bridging Stent Graft System (BeGraft) and the Zenith Unibody2 Endovascular Graft.

The BeGraft, a medical device used in fenestrated endovascular aneurysm repair (FEVAR) procedures, is a cobalt-chromium stent covered on its abluminal side with expanded polytetrafluoroethylene. The stent has diameters ranging from 5 to 10 mm and lengths of 22 to 37 mm. BeGraft is a bridging stent, connecting fenestrations in the main aortic endograft to the target renal and visceral arteries.

The Zenith Unibody2 Endovascular Graft is indicated for the endovascular treatment of patients with abdominal or thoracoabdominal aortic aneurysms in conjunction with the ZFEN+ or other appropriate Zenith proximal device and Zenith iliac leg grafts.

Enrolling in the ZFEN+ Clinical Trial at Penn Medicine

For more information about eligibility for the ZFEN+ study at Penn, please call 215-662-2069.

Research in Complex Endovascular Aortic Devices at Penn Medicine

Penn Medicine has been at the forefront of clinical research in endovascular devices to treat abdominal aortic aneurysms (AAAs) for almost two decades. The Penn Aorta Center is engaged in clinical trials to expand the indications for endovascular stent grafts to include patients with complex and complicated aneurysmal disease, including thoracoabdominal aortic aneurysms, juxtarenal, and pararenal aortic aneurysms.

While a recognized high volume center for aortic surgery, the Penn Aorta Center is involved in clinical research with access to the newest devices through clinical trials (including more than 15 clinical trials).

In addition, the scope of the Penn Aorta Center’s work includes translational applications.

The Center is currently developing an aortic tissue bank to determine how aortic-related genetic changes manifest and how they may influence the decision to intervene.

Clinical consult and patient referral

To refer a patient to Penn Medicine, please call the 24/7 provider-only line at 877-937-7366 or submit a referral through our secure online referral form.

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