The purpose of this study is to gather safety and effectiveness of the Zenith t-Branch and customized physician-specified stent-graft with a combination of fenestrations and/or branches to repair aortic aneurysm.

This is a traditional device feasibility study intended to generate preliminary safety and efficacy information that may be used to plan an appropriate future study, or to inform further product development.

Subjects will have been diagnosed with a bulge or aneurysm in their aortic arch and or abdominal aorta, which is the blood vessel in the abdomen (belly) that supplies blood to most of the lower body including major organs and the legs.

The Zenith t-Branch and physician-specified fenestrated and branched endovascular graft is a tubular graft made of polyester fabric sewn to stainless steel stents that keep the graft open. As an aneurysm expands, the walls become weak and may rupture, causing a major loss of blood with a high risk of death and other serious complications. To avoid this risk the aneurysm will be repaired by putting a graft inside the aneurysm. The graft will be inserted through arteries in the groin (called endovascular repair). This procedure uses catheters that go inside the blood vessel to place a stent-graft above and below the aneurysm.

The graft includes 1 to 5 small holes (fenestrations) or cuffs (side branches). These small holes or branches are the investigational part of this research study. The arteries to the liver, intestine, and kidneys will have a stent (small tubular stainless steel structures) to help keep the arteries open and aligned with the fenestrations or branches. The Zenith t-Branch and physician-specified fenestrated and branched endovascular graft will be referred to as the Zenith Fenestrated-Branched System.

General Inclusion Criteria:

• Thoracoabdominal aortic aneurysm with a diameter ≥ 5.5 cm or 2 times the normal aortic diameter.
• Aneurysm with a history of growth ≥ 0.5 cm per year.
• Saccular aneurysms deemed at significant risk for rupture based upon physician interpretation.
• Presence of concomitant thoracoabdominal and aortic arch aneurysm meeting one of the above-mentioned criteria.
• Presence of thoracoabdominal aortic aneurysm meeting one of the above-mentioned criteria with unilateral or bilateral common iliac artery aneurysm with diameter ≥ 3.0-cm or saccular morphology with no suitable landing zone proximal to iliac bifurcation.

General Exclusion Criteria:

• Less than 18 years of age
• Unwilling to comply with the follow-up schedule
• Inability or refusal to give informed consent by the patient or a legally authorized representative
• Pregnant or breastfeeding
• Life expectancy < 2 years
• Prior open surgical or interventional procedure within 30 days of the anticipated date of the fenestrated-branched procedure, with the exception of planned staged procedures to provide access for repair (e.g. staged iliac conduit, cervical debranching, elephant trunk repair), to facilitate the procedure by allowing open revascularization of a target artery not amenable to revascularization with the investigational device, such as an internal iliac artery, subclavian artery or visceral artery with early bifurcation, tortuosity or occlusive disease preventing successful placement of alignment side stents.
• Participation in another investigational clinical or device trial, with the exception of participation in another investigational endovascular stent-graft protocol, percutaneous aortic valve protocol, or concomitant clinical trials designed to evaluate medical therapy strategies to reduce perioperative risk during fenestrated-branched endovascular repair, including risks of renal dysfunction, contrast-induced nephropathy, neurologic, spinal cord or cardiac complications, and/or use of advanced imaging to reduce radiation exposure during implantation of these devices. Participation in investigational device trials not encompassed by the IDE protocol should be performed remotely from the fenestrated procedure (> 30 days). Examples include remote (>30 days) participation in a thoracic, abdominal or iliac branch device trial, or participation in a percutaneous aortic valve trial. Participation in medical therapy trial or advanced imaging trial designed to improve peri-operative outcomes or to reduce radiation exposure of fenestrated-branched endografts may be concurrent with the IDE study. Examples include therapy directed to reduce rates of spinal cord injury, stroke and contrast-induced nephropathy associated with implantation of fenestrated-branched stent-grafts or advanced imaging trials designed to reduce radiation exposure during repair.
• Patients with ruptured aortic aneurysms requiring urgent or emergent repair, with the exception of patients with contained, stable ruptures with anatomy suitable for an off-the-shelf design.

Medical Exclusion Criteria:

• Known sensitivities or allergies to stainless steel, nitinol, polyester, solder (tin, silver), polypropylene, PTFE, urethane or gold
• History of anaphylactic reaction to contrast material that cannot be adequately pre-medicated
• Leaking or ruptured aneurysm associated with hypotension
• Uncorrectable coagulopathy
• Mycotic aneurysm or patients with evidence of active systemic infection.
• History of connective tissue disorder (e.g vascular Ehlers Danlos, Marfans syndrome), with the exception of those patients who had prior open surgical aortic replacement, where a surgical graft would serve as landing zone for the investigational stent-graft, those who are deemed prohibitive risk for open surgical repair or connective tissue disorders with no effect of vascular system (e.g non-vascular forms of Ehlers Danlos).
• Body habitus that would inhibit X-ray visualization of the aorta and its branches.

Anatomical Exclusion Criteria:

• Inadequate femoral or iliac access compatible with the required delivery systems.
• Inability to perform a temporary or permanent open surgical or endovascular iliac conduit for patients with inadequate femoral/iliac access.
• Absence of a non-aneurysmal aortic segment in the distal thoracic aorta above the diaphragmatic hiatus with: a. A diameter measured outer wall to outer wall of no greater than 42mm and no less than 21 mm; b. Parallel aortic wall with <20% diameter change and without significant calcification and/or thrombus in the selected area of seal zone
• Visceral vessel anatomy not compatible with Zenith t-Branch or patient-specific stent-graft due to excessive occlusive disease or small size not amenable to stent graft placement
• Unsuitable distal iliac artery fixation site and anatomy for iliac limb extension or iliac branch device: a. Common iliac artery fixation site diameter, measured outer wall to outer wall on a sectional image (CT) <8.0 mm with inability to perform open surgical conduit ; b. Iliac artery diameter, measured outer wall to outer wall on a sectional image (CT) >20 mm at distal fixation site, with inability to perform open internal iliac artery revascularization or iliac branch stent graft ; c. Non-aneurysmal external liac artery distal fixation site <10 mm in length ; d. Non-aneurysmal internal iliac artery main trunk or branch segment with length <10mm or with inner wall diameter <4 or >14mm; e. Unsuitable anatomy due to inability to preserve at least one hypogastric artery

Additional anatomical inclusion criteria for aortic arch devices:

• Proximal aortic fixation zone: a. Native aorta or surgical graft; b. Diameter: 20-42mm; c. Proximal neck length ≥ 20mm; d. Ascending aortic length ≥50mm; e. Must occur distal to coronary arteries and any coronary artery bypass grafts that are considered patent and necessary for proper cardiac perfusion
• Distal aortic fixation zone:; a. Native aorta or surgical graft; b. Diameter: 20-42mm; c. Distal neck length ≥20mm
• Supra-aortic trunk (brachiocephalic) vessels: a. Although the prosthesis will typically have two branches, modifications to the design will allow for a single branch, three branches or combination of branch and scallop if a customized version is required. Thus, it is generally planned that at least one extra-anatomic bypass graft will be done in conjunction (or in a staged fashion) with the procedure, unless three branches are planned. The two vessels incorporated into the endograft repair would most commonly be the innominate artery and left common carotid artery. However, the innominate artery may be coupled with the left subclavian artery in the setting of a bovine arch whereby the flow to the left carotid would come from a left subclavian to carotid bypass. Similarly, the left carotid and subclavian artery may be branched, or simply one vessel branched should specific anatomic limitations exist. In such a situation, multiple extra-anatomic bypasses may be necessary. A design with a single subclavian retrograde branch and double scallop to the left carotid artery may be used to extent the landing zone to Zone 1. Finally, a design with two antegrade inner branches for the innominate and left common carotid, and one retrograde inner branch for the left subclavian artery may be used in select cases. Thus the inclusion criteria are defined for each artery, yet any combination of arteries may be used for a repair: Innominate artery (Native vessel or surgical graft, Diameter: 8-22mm, Length of sealing zone ≥10mm, Acceptable tortuosity); Left (or right) common carotid artery (Native vessel or surgical graft, Diameter 6-16mm, Length of sealing zone ≥10mm, Acceptable tortuosity); Left (or right) common carotid artery (Native vessel or surgical graft, Diameter: 5-20mm, Length of sealing zone ≥10mm, Acceptable tortuosity).
• In the setting of an aortic dissection the following criteria must exist: a. Access into the true lumen from the groin and at least one supra-aortic trunk vessel; b. A sealing zone in the target aorta (or surgical graft) that is proximal to the primary dissection, such that a stent-graft would be anticipated to seal off the dissection lumen; c. A sealing zone in the target supra-aortic trunk vessels that is distal to the dissection, anticipated to seal off the dissection lumen, or surgically created; d. A true lumen size large enough to deploy the device and still gain access into the target branches
• In the setting of more distal disease: a. The repair may be coupled with a thoracoabdominal branched device, infrarenal device, and/or internal iliac branch device.
• Iliac anatomy must allow for the delivery of the arch branch device which is loaded within a 20F-24F sheath. Thus the iliac requirements are no different than the standard thoracic protocol. Conduits to the iliac vessels or aorta may be used if deemed necessary.