Physician modification of the Terumo Aortic TREO device for juxtarenal or pararenal aortic aneurysms

Background: The video describes backtable modification of a Terumo aortic Treo device. Combining different cases, our technique of device modification to create home-made fenestrations is presented step by step. This approach enables prompt endovascular interventions for patients with juxta- or para-renal abdominal aortic aneurysms. Access to the fenestrations is typically achieved through the groin. The technique can be adapted to accommodate one to four fenestrations to extend the proximal seal zone. While there are Food and Drug Administration (FDA)-approved custom-made devices available, they currently require significant manufacturing time and may not be suitable for all patient anatomies. As an alternative, physician-modified endografts (PMEGs) have been proposed.1Starnes B.W. Heneghan R.E. Tatum B. Midterm results from a physician-sponsored investigational device exemption clinical trial evaluating physician-modified endovascular grafts for the treatment of juxtarenal aortic aneurysms.J Vasc Surg. 2016 Sep 26; Google Scholar PMEGs provide an off-the-shelf option for patients in need of timely repair, yielding excellent mid-term results.1Starnes B.W. Heneghan R.E. Tatum B. Midterm results from a physician-sponsored investigational device exemption clinical trial evaluating physician-modified endovascular grafts for the treatment of juxtarenal aortic aneurysms.J Vasc Surg. 2016 Sep 26; Google Scholar However, concerns persist regarding the complexity involved in planning, graft modification, and target vessel cannulation.2Simons J.P. Shue B. Flahive J.M. Aiello F.A. Steppacher R.C. Eaton E.A. et al.Trends in use of the only Food and Drug Administration-approved commercially available fenestrated endovascular aneurysm repair device in the United States.J Vasc Surg. 2017 May; 65: 1260-1269Abstract Full Text Full Text PDF Scopus (31) Google Scholar Furthermore, limitations in this technique are attributed to the design features of stent grafts, including narrowly spaced stents that sometimes necessitate the placement of a fenestration over a stent strut.3Starnes B.W. Tatum B. Singh N. Procedural and perioperative results in patients treated with fenestrated endovascular aneurysm repair planned by automated software in a physician-sponsored investigational device exemption trial of physician-modified endografts.J Vasc Surg. 2018 Nov; 68: 1297-1307Abstract Full Text Full Text PDF PubMed Scopus (0) Google Scholar The TA Treo bifurcated graft (Terumo aortic, Somerset, NJ) stands out as an endograft with distinctive attributes. It comprises a series of self-expanding serpentine Nitinol stents sewn onto tightly woven polyester vascular graft fabric. Notably, its suprarenal fixation stent features five suprarenal and infrarenal barbs oriented caudally. During deployment, the suprarenal barbs are shielded by the clasping system until the main body is fully deployed, while the infrarenal barbs remain concealed within the valley of the first covered stent. This design facilitates safe repositioning until the proximal bare stent is released and facilitates resheathing. This combined fixation pattern, along with an enhanced, narrow-overlapping sealing zone, holds promise in preventing dislodgement and caudal migration. One notable feature of this endograft is its relatively sparse use of Nitinol stents in the main body. The Treo model incorporates only 3, 4, and 5 Nitinol springs for bifurcate lengths of 80 mm, 100 mm, and 120 mm, respectively with a strut-to-strut stent distance ∼18mm and the stent rows are staggered so that the space between two stent rows is also ∼18mm. This wide amplitude stent design lends itself for the implementation of fenestrations (Fig 1). For comparison purposes, the Zenith alpha bifurcated graft (Cook Medical, Melbourne Aus.) also presents with a strut-to-strut stent distance of ∼18 mm, but stent rows are separated by ∼6mm while the Zenith Flex bifurcated graft and the Zenith TX2 Dissection Endovascular Graft with Pro-Form (Cook Medical) presents with a strut-to-strut stent distance of ∼5 mm, and stent rows are separated by ∼10mm, which may prove difficult to accommodate multiple fenestrations and large target arteries. The Treo main body boasts a diameter range of 20 to 30 mm, with increments of 2 mm, and can extend up to a maximum diameter of 36 mm, with increments of 3 mm. The ipsilateral limb is available in three lengths: 80 mm, 100 mm, and 120 mm, each with limb gates measuring 14 mm in diameter. Notably, the length of overlap between the main body and the limb extensions is highly adjustable, with a minimum overlap of 2 cm on either side and an adjustable zone of 3 cm and 1 cm for the ipsilateral and contralateral limbs, respectively. Another distinctive feature is the unique "lock-stent" mechanism comprising five rounded bars facing intraluminally and positioned at the caudal end of the second most distal stent of the endograft's limb gates. This mechanism ensures modular fixation and mitigates displacement forces, thereby reducing the risk of dissociation and type III endoleak. Finally, it is a low-profile device with a delivery system of 18Fr outer diameter (OD) for a 20-28mm main body and 19Fr (OD) for a 30-36mm main body. Interestingly, the length from the edge of covered graft to the delivery handle is 49 cm (with a 67 cm handle) making it possible to accommodate Type IV thoraco-abdominal aneurysms. In comparison, the Zenith alpha and Zenith flex bifurcated grafts only offer a 40 and 43cm length respectively when the Zenith TX2 Dissection Endovascular Graft, which is a thoracic endograft, offers a 72cm length (all of them with a 11cm handle). We present a video (Supplementary Video) explaining the different steps to achieve a backtable modification of a TA Treo device to treat juxta- or para-renal aortic aneurysms. Usually, one member of the team is preparing the groins with a cut-down on one side to ease the common femoral artery's repair after sheath's removal secondary to our personal experience with PMEGs where we tent to observe a slight deterioration of the launcher profile after reinsertion of the PMEG. A percutaneous access is performed on the other groin with preclosure using two Proglides (Abbott, Chicago, Ill). During this patient's preparation, a second member of the team is preparing the PMEG in the operating room according to pre-operative planning. The proximal 3 to 4 stents are deployed on the back table, this way the contralateral gate remains in the sheath. The fenestration location is identified on the graft fabric using a sterile pen to mark the distance from the proximal fabric edge and the clock position predetermined during computed tomography-angiography planning. The diameters of the fenestrations range between 6 to 8mm in diameter. Next, an ophthalmic cautery pen is employed to create the fenestration in the graft fabric. Subsequently, the marked area is reinforced using an Amplatz goose neck snare (Medtronic, Minneapolis, Minn) or the proximal tip of a V18 guidewire (Bostin Scientific, Marlborough, MA) sutured around the fenestration in a 360 fashion with a CV5 or CV6 gore-tex lock-stitch running suture (W.L. Gore & Associates, Newark, DE). It is advisable to weigh the benefits of precision/radio-opacity and flexibility against the cost and availability but in our opinion and with our imaging (Cios alpha, Siemens Healthcare), radio-opacity is better with the Amplatz goose neck snare. The modified endograft is subsequently re-constrained using a silastic lace, which is gradually unwrapped as the delivery system sheath is advanced over the endograft. We acknowledge that it can have an impact on the sheath profile. In our experience, independent of the modified device, this technique may enlarge the sheath, compromising its original manufacturing profile and leading to a small step between the nose and the sheath which has proven problematic in some percutaneous cases. Some teams propose an alternative approach where the delivery of the PMEG is facilitated through a previously placed Dryseal sheath (WL Gore & Associates). However, this method results in an increase of at least 2 French in the arterial puncture site. Radiography is conducted prior to implantation to verify the visibility and orientation of the markers (Fig 2). Device modification lasts 20 to 40 minutes depending on the number of fenestrations. After endograft deployment, the contralateral gate is cannulated and a 16 to 20Fr sheath (Cook Medical or Dryseal, WL Gore & Associates) is advanced inside the main body. The target arteries are routinely cannulated through this large sheath, a 6 to 7Fr sheath (KCFW; Cook Medical) is advanced and the target arteries are stented using a balloon expandable iCover stent (iVascular, Barcelona) flared to 9 to 12mm into the main body. One technical point is the possibility of graft collapse in case of rotation of the modified device even after cannulation of the contralateral gate with a large sheath and cannulation of one or more target arteries. On the one hand, it means that no diameter reducing tie is necessary since simply twisting the delivery system handle will allow the graft to torque down to a small diameter, allowing repositioning of the endograft and creation of a gap between the graft and aortic wall if the fenestration is not completely in front of the target vessel's ostium.4Hemingway J.F. Starnes B.W. Kline B.R. Singh N. Initial experience with the Terumo aortic Treo device for fenestrated endovascular aneurysm repair.J Vasc Surg. 2021 Sep; 74: 823-831.e1Abstract Full Text Full Text PDF Scopus (0) Google Scholar On the other hand, it can lead to difficult vessel cannulation because of the presence of graft wrapping inside the main body. Counterclockwise rotation of the graft along with gentle pulling on the delivery system handle will bring the graft back to its original shape and help expedite cannulation. The main body is gradually deployed using a turning knob in the delivery system. This system includes a detachable sheath that can be separated from the main handle, allowing for the introduction of the ipsilateral limb extension. However, to our opinion this sheath is impractical because of excessive length and the absence of lateral tubing for injections. The patient consented in writing to the use of their anonymized intraoperative images and videos for educational purposes. In conclusion, the TA Treo device's wider amplitude stents and larger interstent distances facilitate modifications, reducing the risk of struts crossing fenestrations. This adjustment does not compromise technical success rates or safety, as TA Treo modified devices demonstrate comparable success rates, endoleak occurrences, and major adverse event rates compared to other stent graft types.4Hemingway J.F. Starnes B.W. Kline B.R. Singh N. Initial experience with the Terumo aortic Treo device for fenestrated endovascular aneurysm repair.J Vasc Surg. 2021 Sep; 74: 823-831.e1Abstract Full Text Full Text PDF Scopus (0) Google Scholar eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI1NzQyYzUyOTY2NWE0ZDM2NjlkNWY2YmYzMWZiOGIyNiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNzA4NDE0OTczfQ.HjCeJY6mDXASo-6mt7pg0RDLVlX0jRs-2kvxCKaFmowVOBjYxcTXz9WfAYMHVq0u91UX14uln10stkz0culqCf8wNkoCfUWk2laLO3FNf2FwMxcgB6NPt1GphG6DOqIGh62VLT4K6kvTs84ufh324INVlmhX4oI93XMShrx_7Tt7jAU1FaAgwW7iUP6J9bv8HMS7ZEOsTOqOQ9LVS9edKhKG6NMT3_PB-bd6T-ra9iMwjz_rWOxOy7z21EoR9BDV5GLn38uq4HzxlxC7TOhMtDWhKg8z43Hdaqz3wfC7eY-k1wAPdKTuBoyYUg4EOp9g8_5aQdMpP5ZqzSgNnp9CNw Download .mp4 (38.15 MB) Help with .mp4 files