Vascular News Cryolife supplement – November 2021

November 2021 | Educational Supplement

Inner branches:

iBEVAR advantages in thoracoabdominal aortic aneurysms after chronic aortic dissection vascularnews.com

This educational supplement has been sponsored by Cryolife

Introduction

Inner branches: iBEVAR advantages in TAADs Said Abisi (Guy’s and St Thomas’ NHS Foundation Trust, London, UK) outlines the reasons why inner branched endovascular aneurysm repair (iBEVAR) “serves as a valuable addition to the armamentarium for the treatment of thoracoabdominal aortic aneurysms after chronic aortic dissection (TAADs)”.

TOTAL ENDOVASCULAR treatment of TAADs remains challenging, despite the availability of advanced endovascular solutions like fenestrated and branched endografts, improved device design and increased user experience. The anatomical variations in chronic aortic dissection result in difficulties for accurate planning, with subsequent procedural unpredictability and high reintervention rates.

Patients with chronic aortic dissection typically have a narrow aortic true lumen and the position of the target vessel origin can be inconsistent. Connections, also known as fenestrations, or entry tears, within the dissecting lamella between true and false aortic lumens are often used to access the target vessels coming off the false lumen.

These anatomical features have a significant impact on the planning and execution of these procedures and raise the question of the need for more versatile solutions than the current fenestrated and branched traditional options, a design that offers more freedom in positioning, provides increased confidence to access the target vessels and most importantly, is compatible with a narrow aortic lumen.

Fenestrated repairs have to be strictly planned according to the target vessels’ ostial origins or their relevant entry tears between the true and false lumens. The limited degree of flexibility and accommodation of this design can be very problematic, particularly in the case of misalignment due to procedural or planning reasons. The lack

of consistent inter vessel diameter (IVD) makes planning and positioning fenestrations an arbitrary task.

Branched repairs overcome Said Abisi the challenge of planning unpredictability but require a wider aortic lumen to allow the outer or external component of the branch to open safely without it being compressed or kinked.

Unfortunately, in chronic dissection the true lumen is often compressed and it is impossible to predict if it will expand enough during the repair. Even if the aortic true lumen is relatively wide it is not uncommon for patients with TAADs to have undergone previous intervention. In this situation,

Chronic aortic dissection seems to be the ideal frontier for iBEVAR to prove its applicability as a promising solution to overcome the limitations of other options.”

Case report: iBEVAR in TAAD: How we managed a small true lumen diameter According to Carmelo Ricci, Laura Candeloro and Eugenio Neri, colleagues at Azienda Ospedaliera Universitaria Senese in Siena, Italy, inner branched endovascular aneurysm repair (iBEVAR) is a “favourable choice” for the treatment of thoracoabdominal aortic aneurysm after chronic aortic dissection (TAAD), as they evidence in the following case report.

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potential friction or interaction with external or outer branches may increase the difficulty of the intervention.

IBEVAR offers the best of both options: inner branches are located entirely inside the main endograft and therefore it is ideal for a narrow aortic lumen; and there is no risk of branch compression in a narrow aortic lumen between the endograft and aortic wall during deployment. The inner branched design is highly tolerant to the variability in the target vessel’s location. The internal branch can be placed vertically just above and rotationally within a range in the proximity of the target vessel to allow for cannulation and placement of the bridging stent graft. Inner branches do not need to be positioned or deployed precisely at the target vessel level or clock/degree position in the same fashion as fenestrated repairs. This is particularly important in cases with anatomical unpredictability such as chronic aortic dissection where reliable and predictable planning is not always possible.

It is important to acknowledge that the overall experience in complex endovascular repair in this subset of patients with TAADs is still limited but nevertheless evolving and there is a need for versatile design to allow us to treat more patients with TAADs. The increasing use of iBEVAR in hostile and peculiar anatomies where standard fenestrated EVAR (FEVAR) and branched EVAR (BEVAR) are not appropriate has allowed endovascular specialists to broaden their options and build their confidence with the technology. Chronic aortic dissection seems to be the ideal frontier for iBEVAR to prove its applicability as a promising solution to overcome the limitations of other options and serve as a valuable addition to the armamentarium for the treatment of TAADs. Said Abisi is a consultant vascular and endovascular surgeon at Guy’s and St Thomas’ NHS Foundation Trust in London, UK. TAAD IS AN UNCOMMON CONDITION that involves the descending and the abdominal aorta, with major complications such as organ malperfusion and rupture.

Even if the primary treatment of uncomplicated TAAD remains medical, for patients who develop complications, endovascular or surgical intervention is mandatory.

In order to prevent and treat malperfusion, it is very important to preserve the patency of the visceral vessels. Nowadays, an endovascular approach, so either fenestrated or branched endovascular aneurysm repair November 2021

AOU Senese experience

Carmelo Ricci

Laura Candeloro

iBEVAR advantages in TAADs

Eugenio Neri

(F/BEVAR), allows a physician to treat TAAD while preserving vessel patency.

The FEVAR technique is more complex and time consuming due to the difficulty of correctly positioning each hole in front of the ostium of each artery in the presence of two dynamic lumina. BEVAR is our first endovascular choice for TAAD for the reasons of better seal and fixation for the stents and a more suitable positioning of the branch in relation to the target vessel. The use of inner branches instead of external branches is a favourable choice because the total graft diameter is smaller and also the iBEVAR technique allows the branches to stay firm.

Indeed, the presence of a duplex lumen, often with the true lumen characterised by a very small diameter, even just a few millimeters (Figure 1), reduces the size of the entrance to the correct graft opening, with a major risk of graft enfolding. In our experience, the endovascular fenestration of the intimal flap optimises the landing zone and avoids the risk of graft enfolding.

We performed this procedure under general anaesthesia and systemic heparinisation.

In order to navigate the true and the false lumen we needed two vascular femoral accesses, and a third access (humeral or axillary artery), to perform diagnostic angiography. After correctly identifying true versus false lumen, we navigated the true lumen with a stiff guidewire.

After locating a suitable landing zone, we created a tear in the intimal flap. In order to avoid damage to the aortic wall, we used an intravascular ultrasound (IVUS) catheter in the false lumen. We created a tear with a recanalisation guidewire (a radiofrequency guidewire could also be used), that we advanced from the true to the false lumen (Figure 2A). By the means of the femorofemoral through-and-through wire technique, we replaced the recanalisation guidewire with a polytetrafluoroethylene (PTFE)-coated guidewire.

In the false lumen, after removing the IVUS catheter, we placed a gooseneck snare, closed it with the tip of the PTFE guidewire inside the snare, and finally withdrew it from the sheath (Figure 2B). It is necessary to put two long introducer sheaths in the two femoral accesses in order to protect the iliac arteries during the fenestration.

Finally, we pulled down the PTFE November 2021

Figure 1. The true lumen diameter before the fenestration.

Figure 2. The puncture of the intimal septum (A) and the guidewire captured in the snare (B).

Figure 3. The final result: angiographic (A) and CT imaging (B, C): just one aortic lumen and regular branches, with enough space for the correct graft deployment.

The one-month follow-up angioCT demonstrates the correct graft deployment in just one aortic lumen and the patency of the vessels.” guidewire toward the newly created tear in the intimal flap, with a “pushing and pulling” movement to cut the intimal flap in order to make a suitable longitudinal fenestration until the aortic carrefour, avoiding intimal layer stripping. Once the fenestration was completed, it was possible to deploy the inner branched graft and to stent the vessels.

The one-month follow-up angio-computed tomography (CT) demonstrates the correct graft deployment in just one aortic lumen and the patency of the vessels (Figures 3A–C).

In conclusion, our experience suggests that the first fenestration step is very important in setting up enough space to expand a branched graft. In fact, the inner branched graft

allows for the treatment of TAAD, but in the presence of a very small true lumen, the graft may have not enough space to correctly expand itself or its branches. This potential complication needs to be addressed.

Carmelo Ricci is the head of the Interventional Radiology Unit in the Radiology Department at AOU Senese in Siena, Italy.

Laura Candeloro is an interventional radiologist at AOU Senese.

Eugenio Neri is chief of the Cardiac and Great Vessels Surgery Unit at AOU Senese.

References 1. Ricci C, Ceccherini C, Leonini S, et al. JAG tearing technique with radiofrequency guide wire for aortic fenestration in thoracic endovascular aneurysm repair. Cardiovasc Intervent Radiol 2012; 32: 176–179.

2. Chavan A, Hausmann D, Dresler C, et al. Intravascular ultrasound-guided percutaneous fenestration of the intimal flap in the dissected aorta. Circulation 1997; 97: 2124–2127.

3. Schepens M. Type B aortic dissection: New perspectives. J Vis Surg 2018; 4:75.

4. Parsa CJ, Williams JB, Bhattacharya SD, et al. Midterm results with thoracic endovascular aortic repair for chronic type B aortic dissection with associated aneurysm. J Thorac Cardiovasc Surg 2011; 141: 322–7.

5. E rbel R, Aboyans V, Boileau C, et al. 2014 ESC guidelines on the diagnosis and treatment of aortic diseases: Document covering acute and chronic aortic diseases of the thoracic and abdominal aorta of the adult. The Task Force for the Diagnosis and Treatment of Aortic Diseases of the European Society of Cardiology (ESC) Eur Heart J 2014 Nov 1; 35(41): 2873–926.

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University Hospital of Lausanne experience

Case report: iBEVAR as a solution for a thoracoabdominal aneurysm due to chronic type A dissection The main goal of iBEVAR [inner branched endovascular aneurysm repair] is to be effective in a wide range of aortic anatomies, Sébastien Déglise, Elisabeth Côté and Céline Deslarzes-Dubuis, colleagues at the University Hospital of Lausanne in Lausanne, Switzerland write, concluding that postdissection thoracoabdominal aortic aneurysm (TAAA) seems to be a suitable indication for the procedure.

trunk and to extend up to 2cm above the coeliac trunk. In the final step, six weeks later, we decided to implant an endograft with four inner branches given the small true lumen. An inner branch-based stent graft (Jotec/Cryolife) comprising four precannulated antegrade inner branches was implanted and prolonged distally with a bifurcated main body and two iliac limbs to seal in the common iliac arteries. All the target vessels were cannulated from a left axillary approach using an 8.5Fr Destino Twist long deflectable steerable guiding sheath (Oscor). Viabahn VBX stent grafts (W L Gore & Associates) were used as bridging stents. The patient benefited intraoperatively from cerebrospinal fluid drainage and neuromonitoring. The first postoperative computed tomography (CT) revealed a fully expanded stent graft (Figure 2A) with all branches patent and an excluded aneurysm (Figure 2B, C). The patient had an uneventful recovery and follow-up CT angiography (CTA) confirmed the good initial results with an excluded aneurysm, a small type II endoleak in the false lumen and patent inner branches (Figure 3).

Discussion

Figure 1. Aneurysmal degeneration of the dissected descending thoracic aorta with a maximal diameter of 59mm (A). Origin of the right renal artery from the small elliptical true lumen (B). The dissection and the aneurysm started form the arch up to the iliacs (C).

Case

A 67-year-old man known for hypertension and Crohn’s disease underwent an operation in 2012 for acute type A aortic dissection with graft replacement of the ascending aorta. During follow-up, he developed an aneurysmal degeneration of his aorta, which reached the false lumen at the level of the descending aorta with a maximal diameter of 59mm (Figure 1A). The aneurysm and the dissection extended from the arch up to the iliacs (Figure 1B). The four target vessels originated from the small elliptical true lumen (Figure 1C).

Given the extension and the complexity of the disease, we decided to treat the patient

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in three steps. Firstly, he underwent a total arch replacement with an elephant trunk and reimplantation of the supra-aortic vessels.

Two weeks later, we performed a thoracic endovascular aortic repair (TEVAR) with three Tag Conformable stent grafts (W L Gore & Associates) to freeze the elephant

Considering the high risks of complications and mortality, an endovascular approach is becoming increasingly popular for treating post-dissection TAAAs. In order to be able to work in the narrow space of the true lumen, the graft design of choice was a four-vessel fenestration. This strategy is reported to be safe and to bring good technical success of more than 90% and mid-term survival.1 However, a fenestrated endovascular aneurysm repair (FEVAR) strategy carries some limitations.

The most important drawback is the need for accurate stent graft placement, especially in the case of a narrow lumen, angulation or previous EVAR. In this context, the use of branches allows for more flexibility and good results have been reported on the use of the t-branch endograft, especially in an urgent setting.2 Nevertheless, the endovascular treatment of post-dissection TAAAs is technically more demanding, due to a small lumen and potential navigation difficulties between true and false lumens.

Indeed, one major concern with the use of

As endovascular thoracoabdominal aortic aneurysm repair remains very challenging, everything should be done to improve its intraoperative management.”

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iBEVAR advantages in TAADs

Figure 2. Postoperative images showing the fully deployed inner-branched endograft with all four inner branches opened with patent bridging stents. Anterior (A) and lateral view (B). Complete exclusion of the aneurysmal sac (C). Patent SMA inner branch (D).

outer branches in post-dissection aneurysm is the risk of branch opening in the false lumen through an entry tear, as described by Justine Mougin (Hôpital Marie Lannelongue, Groupe Hospitalier Paris Saint Joseph, Université Paris Saclay, Paris, France) et al.2 A custommade stent graft with inner branches adapts perfectly to such complex anatomies of post-

dissection aneurysms, bringing the branch outlets close to the aortic wall and the target vessels, allowing for easier catheterisation and the use of shorter bridging stents with better sealing. Moreover, the new wider outlet design offers flexibility in the graft planning and positioning, in order to ensure better long-term outcomes.

Recently, Said Abisi (Guy's and St Thomas' NHS Foundation Trust, London, UK) et al reported the first experience with the E-xtra Design Engineering stent graft (Jotec/Cryolife) in 18 patients.3 The presence of a narrow lumen was a selection criterion in 78% of cases. The graft shows promising results with high technical success and without any major complications or death. The authors also confirmed that it was possible to treat such patients with a retrograde femoral approach. They concluded that this strategy has the potential to be a useful addition to our armamentarium for treating complex aortic disease. However, longer follow-up and additional patients are required before widespread adoption of this encouraging technology. Indeed, some concerns exist regarding its application in dissected aorta, as raised by Stéphan Haulon (Hôpital Marie Lannelongue, Groupe Hospitalier Paris Saint Joseph, Université Paris-Saclay, Gif-sur-Yvette, France) et al.4 The presence of four inner branches in a narrow environment might sufficiently reduce the graft lumen in order to create a stenotic effect with impaired distal perfusion of the kidneys and the legs. In case of a very small aortic lumen, a solution could be to

limit the use of inner branches to the targets vessels with a steep trajectory and to use fenestrations for other vessels with more favourable direction.4 As endovascular TAAA repair remains very challenging, everything should be done to improve its intraoperative management. The main goal of inner branched endovascular aneurysm repair (iBEVAR) is to be effective in a wide range of aortic anatomies, reducing the potential consequences of planning errors. Postdissection TAAA seems to be a suitable indication for iBEVAR. Sébastien Déglise is a vascular surgeon at the University Hospital of Lausanne in Lausanne, Switzerland.

Elisabeth Côté is affiliated with the Department of Vascular Surgery at the University Hospital of Lausanne.

Céline Deslarzes-Dubuis is a vascular surgeon at the University Hospital of Lausanne.

References 1. Spear R, Hertault A, Van Calster K, et al. Complex endovascular repair of postdissection arch and thoracoabdominal aneurysms. J Vasc Surg 2018; 67: 685–693.

2. Mougin J, Oderich GS, Multon S, et al. Commentary: Urgent repair of postdissection thoracoabdominal aortic aneurysms using branched endografts. J Endovasc Ther 2020 Dec; 27(6): 929–935.

3. Abisi S, Zymvragoudakis V, Gkoutzios P, et al. Early outcomes of Jotec inner-branched endografts in complex endovascular aortic aneurysm repair. J Vasc Surg 2021 Sep; 74(3): 871–879.

4. Haulon S, Mougin Le Houerou T, Fabre D. Invited commentary: Innovative approaches and new endograft designs to perform complex endovascular thoracoabdominal aortic aneurysm repair. J Vasc Surg 2021 Sep; 74(3): 880–881.

Figure 3. A. Followup 3D CTA showing total arch repair with complete exclusion of the aneurysm and correct positioning of the thoracic and the inner-branched endografts. Patency of the four inner branches in lateral (B) and anterior view (C).

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The John Paul II Hospital experience

Case report: Successful implantation of a thoracoabdominal inner branched E-xtra Design Engineering stent graft Based on positive case results, Rafał Maciąg, Mariusz Trystuła and Jakub Zasada, colleagues at The John Paul II Hospital in Krakow, Poland, write that inner branch technology offers a “good solution” for thoracoabdominal aortic aneurysms after chronic aortic dissection (TAADs).

Case presentation

A 41-year-old male patient was hypertensive but not taking antihypertensive medication after the implantation of a thoracic stent graft in 2020 to treat an acute aortic dissection.

According to the Society for Vascular Surgery (SVS)/Society of Thoracic Surgery (STS) classification system, chronic dissection patients have a type B aneurysm with type R entry flow (Figure 1). It is clear from the literature that thoracic endovascular aortic repair (TEVAR) has proved to be an effective way to manage patients with acute complicated type B aortic dissection (TBAD)

Rafał Maciąg

Mariusz Trystuła

Jakub Zasada

with improved aortic remodelling and long-term survival compared with medical therapy alone. Thus, it is intuitive that the indications for TEVAR would be expanded to include patients with uncomplicated TBAD who are at high risk for aorta-related

complications in the future.2 Traditionally, resting antihypertensive therapy has been the standard treatment for acute TBAD, but aggressive acute-phase surgical intervention by TEVAR has now become widespread for complicated TBAD. In recent years, the indication has expanded to include uncomplicated TBAD with the intention of preventing future aortic events.3 Despite the implantation of a stent graft to close the dissection, the false lumen increased >10mm over the course of 10 months (Figure 2). Therefore, a decision was made to perform endovascular repair of the dissection with a thoracoabdominal branched stent graft.

Procedure

Surgery was carried out under general anaesthesia. Systemic heparin was administered at a dose of 100IU/kg with a target activated clotting time throughout the procedure of >300s. Left femoral access was obtained using a 24Fr 33cm sheath. Right axillary access was obtained using a 12Fr 45cm sheath. The through-and-through wire technique to introduce a multibranch stent graft was used to allow for the positioning of the inner branched graft. With the technical support of an E-xtra Design Engineering device (Jotec/Cryolife), a thoracoabdominal, multibranch, custom-made device was manufactured, delivered and implanted.

The E-xtra Design Engineering device had four inner branches: three antegrade inner branches for the coeliac trunk, superior

Figure 1. SVS/STS Aortic Dissection classification system of dissection subtype according to zone location of primary entry tear (A), type R entry flow is antegrade flow from the true lumen to the false lumen (B),1 CTA imaging (C).

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iBEVAR advantages in TAADs

Figure 2. Growing of false lumen. Diameter of false lumen before thoracic stent graft implantation (A), six months after thoracic stent graft implantation (B), three months after iBEVAR (C).

mesenteric artery (SMA) and right renal artery (RRA), and one retrograde inner branch for the left renal artery (LRA) with an integrated bifurcation.

Because of the narrow true lumen on the level of the visceral arteries, the inner branched graft was introduced and opened partly in the false lumen going through the entrance of the dissection on the SMA level (Figure 3). The multibranch stent graft in the entrance of the dissection did not open to a nominal diameter of 22mm. For better blood flow, simultaneous inflation of three balloons was applied (Figure 4).

Postoperative course

Digital subtraction angiography imaging and postoperative controls by contrast-enhanced ultrasound confirmed successful occlusion of the abdominal aneurysm with preservation of the coeliac trunk, SMA, and the right and left renal arteries.

On the first postoperative day after the final stage of the procedure, the patient was transferred to the regular ward. The patient was discharged on the sixth postoperative day.

Computed tomography angiography (CTA) imaging confirmed successful occlusion of the false lumen with preservation of the coeliac trunk, SMA, and the right and left renal arteries at three-month follow-up (Figure 5).

An additional benefit was the reduction of the false lumen diameter three months after implantation (Figure 2C).

References 1. Lombardi JV, Hughes GC, Appoo JJ, et al. Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) reporting standards for type B aortic dissections.

Journal of Vascular Surgery 2020 Mar; 71(3): 723–747.

2. Schwartz SI, Durham C, Clouse WD, et al. Predictor of late aortic intervention in patients with medically treated type B aortic dissection. Journal of Vascular Surgery 2018 Jan; 67(1): 78–84.

3. Uchida T, Sadahiro M. Thoracic endovascular aortic repair for acute aortic dissection. Annals of Vascular Diseases 2018 Dec; 11(4): 464–472.

Conclusion

Inner branch technology could be a good solution in TAADs where the design of outer branches is not applicable due to the aortic diameter being too narrow or where fenestrations would not be indicated due to the presence of a thrombus or kinking of the aorta.

In addition, it helps to avoid compression of the branches and ensures proper blood flow in the aorta and visceral arteries.

Figure 4. Simultaneous inflation of three balloons in inner branches for SMA and RRA and inside of iBEVAR.

Rafał Maciąg is an interventional radiologist at the Medical University of Warsaw in Warsaw, Poland, and at The John Paul II Hospital in Krakow, Poland.

Mariusz Trystuła is a vascular surgeon at The John Paul II Hospital.

Figure 3. Narrow true lumen (A, B), entrance of dissection (C, D).

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Jakub Zasada is a vascular surgeon at The John Paul II Hospital.

Figure 5. Three-month follow-up.

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