Physician Modified Endograft For Complex Aortic Aneurysm Repair

May 8, 2023 updated by: Andrew Barleben, University of California, San Diego

A Single-Arm, Single-Center, Non-Randomized, Prospective Clinical Study to Evaluate the Safety and Effectiveness of Physician Modified Endograft for Complex Abdominal and Thoracoabdominal Aortic Aneurysm Repair

The physician modified endograft is intended for treating complex, pararenal, juxtarenal and thoracoabdominal aortic aneurysms requiring coverage of renal arteries, the superior mesenteric artery or the celiac trunk in high-risk patients who do not have an option for endovascular repair with an FDA approved endograft and have an appropriate anatomy. There will be one investigational site with a total of 40 subjects to be enrolled. Time to complete enrollment will be 24 months and the subject follow-up time will be five years from last subject enrollment.

The primary safety endpoint is freedom from major adverse events (MAE) at 30 days or during hospitalization if this exceeds 30 days. The primary effectiveness endpoint is the proportion of study subjects with treatment success at one year. The subjects will be followed at one month, six months, one year, and yearly thereafter for a total period of five years. Subjects will be followed up clinically for life. Clinical exam follow up may be phone or video visit with CT scan evaluation and duplex ultrasound as needed. The proportion of treatment group subjects that achieve and maintain treatment success annually to five years will be investigated.

Study Overview

Detailed Description

The devices that will be used are Cook Medical © devices designed and approved for thoracic aortic and perivisceral aortic disease. These devices are all constructed of full-thickness woven polyester fabric sewn to self-expanding stainless steel or nitinol Cook-Z stents with braided polyester and monofilament polypropylene suture. The grafts are available in a straight or tapered configuration, both of which are fully stented to provide stability and the expansile force necessary to open the lumen of the graft during deployment. These include Zenith TX2 Dissection Endovascular Grafts, The Zenith Alpha Thoracic Endovascular Graft and the Zenith Fenestrated Abdominal Aortic Aneurysm (AAA) Endovascular Graft. These are all modular components that can be modified in a similar fashion. These can be used in conjunction with extension pieces for the Fenestrated AAA endograft system to extend into the iliac arteries.

The goal of this IDE is to repair complex aortic aneurysms involving the visceral vessels (renal arteries, superior mesenteric artery and/or celiac artery) while maintaining a minimally invasive approach. This requires a patient specific approach to each graft in order to land in normal artery above and below the disease.

The majority of the aneurysms treated will fall into the thoraco-abdominal aneurysm classification but there will be perivisceral aneurysms that involve one or more of the visceral vessels as well. These will involve fenestrations if preservation of flow is required in a landing zone or branches if preservation of flow is in the middle of the repair. All of these types of aneurysms do not have FDA approved devices to treat them. The investigators propose an approach to these aneurysms of at least 2 cm of seal proximal and distal to the aneurysmal disease. As this requires branches or fenestrations to preserve flow to the vital visceral vessels. Achieving at least 2 cm of seal within the normal aorta or iliac arteries.

Using these tenants, the approach to a repair and device choice is as follows. The investigators will evaluate the CT scan of the patient with an aneurysm that is off IFU for any other device who is high risk for a traditional open repair. The investigators will then identify the proximal and distal landing zones. If they involve any of the visceral vessels to do a peri-visceral nature, then these will likely be planned to be fenestrations. If they are not in the seal zone but in the middle of the aneurysm they will be planned as branches. Device size selection is based on the landing zone diameter and based on the device IFU.

A staged approach may be used to minimize risks that may be associated with a single extensive repair or improve technical success. This may include but not limited to performing a TEVAR landing above the diseased aorta at least 2 cm into normal thoracic aorta or open aortic graft down to the level of the celiac artery, treatment of a dissection with either a dissection stent or septotomy, or preoperative stenting or embolization of stenotic vessels or accessory vessels that will be covered and excluded during PMEG implantation to prevent endoleak. The potential benefit of a staged approach is one of ischemic conditioning of the spinal cord or staged microembolization to the lumbar arteries in order to minimize ischemic events and space them out over two procedures allowing alternative flow to the spinal cord to improve. There is also a benefit of staging the amount of contrast and fluoroscopy required to perform all of these procedures minimizing the impact of potential radiation exposure to patient and operator and the risk of contrast induced nephropathy. The staged procedure will be 2-4 weeks prior to PMEG implantation.

Once the plan is made and the devices are selected, the main modified device is created on a back table while the patient is being prepared by anesthesia using a plan that is measured from a CT scan with 1 mm cuts or finer in order to have precise and accurate measurements of the following criteria for each vessel:

  1. Diameter
  2. Length to first major branch (that cannot be covered)
  3. Arc length / clock location in comparison to reference vessel (SMA)
  4. Longitudinal distance from reference vessel (SMA)
  5. Angiographic view of the orifice of the vessel for optimal chance of cannulation
  6. Size of the aortic flow lumen at the origin of the target visceral vessel
  7. Degree of angulation at the vessel origin
  8. Predominant trajectory of the vessel (lateral vs cranial vs caudal) Once this is done then the investigators deploy the appropriately sized endograft for modification on a back table. This graft is sized per IFU to the patient's aorta at the location of the landing zones. If the patient has challenging access (small external iliac artery diameters) then the device of choice for modification is more likely to be the Cook Alpha device as this has a lower profile for delivery ensuring technical success of this portion of the procedure minimizing access complications such as iliac dissection and rupture. Also if there are primarily or only fenestrations in the plan for repair, then the investigators will also likely consider or commit to an alpha device as this device has more space between stent struts and there is more difficulty resheathing it with branches due to the smaller sheath size. Otherwise the Cook ZDEG device will be modified as this also does not have a precurved nature to it allowing for more precise delivery and has less difficulty with the resheathing process. If the proximal landing zone is in the visceral segment of the aorta, then the investigators will use the Cook Fenestrated Zenith device as it has a built-in constraining wire and is built for a transfemoral approach for a juxtarenal AAA or pararenal AAA.

Modification Process

  1. Deploy the graft on the sterile, surgical table
  2. Mark out on the graft the locations of the fenestrations on the graft adjusting as necessary to avoid placing fenestrations over stents
  3. Using handheld electrocautery, fashion the fenestration in the appropriate location on the moistened graft material in order to prevent inadvertent progression of the fenestration size
  4. If the fenestration is going to remain as such, then an EV3 Gooseneck snare is used to fashion the marker on the fenestration with Gore 5-0 stitch
  5. If the fenestration is going to be made into a branch, then an appropriately sized Gore, self-expanding stent is beveled and fashioned to be 15 mm long and sewn to the fenestration in addition to a EV3 Gooseneck snare with the Gore 5-0 stitch.
  6. Two orientation markers are placed at the proximal edge and distal edge of the graft consisting of portions of the EV3 Gooseneck snare sewn to the anterior portion of the graft in a "J" fashion with a Gore 5-0 stitch.
  7. The Graft is then sequentially constrained with care taken to ensure that the markers and branch orientation remain true.

Graft Implantation Process

  1. Graft orientation markers and fenestrations are identified under fluoroscopy in an extracorporeal manner with rotation in order to ensure markers are in location both front to back and side to side. This is completed both prior to resheathing and after. This is again confirmed when inserted to the appropriate level in the body.
  2. Using fusion imaging, the distal portions of the branches are put to 1-2 cm above the orifices of the arteries or fenestrations nearly at but slightly above the origins of the arteries.
  3. Once the graft has been delivered to the appropriate location, the graft is unsheathed one aortic stent at a time until the first branch has been deployed.
  4. Then from above, the vessels are sequentially cannulated with a wire and catheter with a catheter angiogram confirming the correct vessel.
  5. The bridging balloon expandable Gore VBX stents are then delivered over wire maximizing overlap with the target vessel and the branch while flaring proximally 2-4mm into the main body of the endograft.
  6. Once devices have been deployed, flow is ensured to be uninhibited by stenosis or dissection with a selective angiogram and then the endo grafting is extended distally into a previously placed endograft, normal aorta or surgically replaced aorta.
  7. Once completed another completion angiogram is performed to ensure flow through all the branch vessels, and no major correctable endoleaks.

Study Type

Interventional

Enrollment (Anticipated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • California
      • San Diego, California, United States, 92037
        • Recruiting
        • University of California San Diego
        • Contact:
          • Andrew Barleben, MD, MPH
        • Contact:
          • Sina Zarrintan, MD, MS, MPH

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

---Inclusion criteria---

  1. Patient is > 18 years of age
  2. Patients who are male or non-pregnant female (females of child bearing potential must have a negative pregnancy test prior to enrollment into the study)
  3. Patient is able and willing to sign an Institutional Review Board (IRB) approved Informed Consent Form
  4. Patient has a complex, juxtarenal, pararenal or thoracoabdominal abdominal aortic aneurysm (Extent I-V) that meets at least one of the following:

    • Aortic aneurysm with diameter ≥ 5.5cm
    • Aortic aneurysm with a history of growth ≥0.5cm in the last 6 months
    • Symptomatic aortic aneurysm
  5. Cannot be treated with a currently available non-modified approved device
  6. High risk for open surgical repair based on any of the factors below:

    1. Anatomic i. Previous abdominal surgery ii. Previous left-sided thoracotomy (if the proposed open repair would require dissection of the thoracic aorta) iii. Previous aortic surgery
    2. Physiologic i. ASA Category III or higher ii. Age >70 years iii. Previous myocardial infarction, coronary artery disease, or coronary artery stent iv. Coronary stress test with a reversible perfusion defect v. Congestive heart failure vi. COPD
  7. Patient has patent iliac or femoral arteries that will allow endovascular access with the physician modified endovascular graft or is suitable for an iliac conduit
  8. Patient has a suitable non-aneurysmal proximal aortic neck length (seal zone) of ≥ 20 mm
  9. Patient has a suitable non-aneurysmal distal iliac artery length (seal zone) of ≥ 15 mm.
  10. The resultant repair should preserve patency in at least one hypogastric artery.
  11. Patient has a suitable non-aneurysmal proximal aortic neck diameter between 15 and 42mm
  12. Patient has suitable non-aneurysmal distal common iliac diameters between 7 and 20 mm.

---Exclusion Criteria---

-General Exclusion Criteria-

  1. Patient has a mycotic aneurysm
  2. Patient has a ruptured aneurysm requiring urgent or emergent repair
  3. Patient has a systemic or local infection that may increase the risk of graft infection
  4. Patient has a body habitus that would inhibit X-ray visualization of the aorta.
  5. Patient is willing and eligible to participate in a manufacturer-sponsored clinical study at another institution
  6. Patient has a major surgical or interventional procedure planned within +/- 30 days of the (T)AAA repair.
  7. Patient is currently participating in another investigational device or drug clinical trial.

-Medical Exclusion Criteria-

  1. Patient has a known hypersensitivity or contraindication to anticoagulation or contrast media that is not amenable to pre-treatment.
  2. Patient has a known allergy or intolerance to stainless steel, polyester, polypropylene, nickel, titanium or gold.
  3. Patient has uncorrectable coagulopathy
  4. Patient has unstable angina (defined as angina with a progressive increase in symptoms, new onset at rest or nocturnal angina, or onset of prolonged angina)
  5. Patient has history of connective tissue disease (e.g., Marfan's or Ehler's-Danlos syndrome).
  6. Patient has active malignancy with life expectancy of less than 2 years
  7. Patient has a limited life expectancy of less than 2 years.
  8. Patient has other medical, social or psychological conditions that, in the opinion of the investigator, preclude them from receiving the pre-treatment, required treatment, and post-treatment procedures and evaluations.

-Anatomic Exclusion Criteria-

  1. Significant occlusive disease, tortuosity or calcification that would prevent endovascular access
  2. Proximal seal site with a circumferential thrombus/atheroma
  3. Inability to maintain at least one patent hypogastric artery
  4. Shaggy aorta
  5. Patient is not amenable to a temporary or permanent open surgical or endovascular conduit

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Physician-Modified Endograft
This is a single arm study used to evaluate the safety and effectiveness of fenestrated and branched techniques for the treatment of patients with a complex, juxtarenal, pararenal or thoracoabdominal abdominal aortic aneurysms (Extent I-V).

Modification

  • Deploy the graft on the sterile, surgical table
  • Mark out on the graft the locations of the fenestrations on the graft adjusting as necessary
  • Using handheld electrocautery, fashion the fenestration in the appropriate location on the moistened graft material in order to prevent inadvertent progression of the fenestration size
  • If the fenestration is going to remain as such, then a snare is used to fashion the marker on the fenestration with 5-0 stitch
  • If the fenestration is going to be made into a branch, then an appropriately sized, self-expanding stent is beveled and fashioned to be 15 mm long and sewn to the fenestration in addition to a snare with the 5-0 stitch
  • Two orientation markers are placed at the proximal edge and distal edge of the graft consisting of portions of the snare sewn to the anterior portion of the graft in a J fashion with a 5-0 stitch

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
The Primary Safety Endpoint (Freedom from major adverse events [MAE])
Time Frame: At 30 days or during hospitalization if this exceeds 30 days.
Major adverse events include death, bowel ischemia, myocardial infarction, paraplegia, renal failure, respiratory failure, and stroke.
At 30 days or during hospitalization if this exceeds 30 days.
Primary effectiveness endpoint
Time Frame: The primary effectiveness endpoint is the proportion of study subjects with treatment success at 1 year.

Treatment success is defined as a composite of technical success and freedom from the following:

  • Aneurysm enlargement [i.e., >5mm as compared to any previous CT measure using orthogonal (i.e, perpendicular to the centerline) measurements]
  • Aneurysm rupture
  • Aneurysm-related mortality
  • Conversion to open repair
  • Secondary intervention for migration, Type I and III endoleaks, device integrity failure (e.g., fracture), and patency-related events (i.e., device component stenosis or occlusion and embolic events)
The primary effectiveness endpoint is the proportion of study subjects with treatment success at 1 year.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Technical success
Time Frame: Procedural

Technical success and the individual components of technical success:

  • Successful delivery
  • Deployment at the intended implantation site
  • Patency of all endovascular graft and stent components
  • Absence of device deformations requiring unplanned placement of an additional device
  • Absence of inadvertent occlusion of aorta or aortic branch vessels
  • Successful withdrawal of delivery systems
Procedural
The individual components of the primary safety endpoint at 30 days or during hospitalization if this exceeds 30 days
Time Frame: At 30 days or during hospitalization if this exceeds 30 days.
  • All-cause mortality
  • Myocardial infarction
  • Respiratory failure requiring prolonged (>24 hours from anticipated) mechanical ventilation or reintubation
  • Renal function decline resulting in >50% reduction in baseline eGFR or new-onset dialysis
  • Bowel ischemia requiring surgical resection or not resolving with medical therapy
  • Major stroke
  • Paraplegia
At 30 days or during hospitalization if this exceeds 30 days.
Follow-up outcomes
Time Frame: The subjects will be followed at one month, six months, one year, and yearly thereafter for a total period of five years.

The following at each follow-up interval:

o Treatment success and the individual components of treatment success including freedom from the following:

  • Aneurysm sac changes (i.e enlargement, shrinkage, no change)
  • Aneurysm-related mortality
  • Aneurysm rupture
  • Conversion to open repair
  • Secondary intervention for migration, type I and III endoleaks, device integrity failure (i.e., fracture), and patency-related events (i.e., device stenosis or occlusion and embolic events).
  • Renal failure
  • All-cause mortality
  • Endoleaks
  • Device integrity failure (e.g., fracture)
  • Patency-related events (i.e., device stenosis or occlusion and embolic events)
  • Other device-related events
The subjects will be followed at one month, six months, one year, and yearly thereafter for a total period of five years.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 1, 2023

Primary Completion (Anticipated)

December 1, 2025

Study Completion (Anticipated)

December 1, 2029

Study Registration Dates

First Submitted

April 14, 2022

First Submitted That Met QC Criteria

April 14, 2022

First Posted (Actual)

April 21, 2022

Study Record Updates

Last Update Posted (Actual)

May 9, 2023

Last Update Submitted That Met QC Criteria

May 8, 2023

Last Verified

May 1, 2023

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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