In situ fenestration of the Nexus aortic arch endograft with reentry catheter in urgent cases non-eligible for total supraaortic debranching
| Available Online: | May, 2024 |
| Page: | 117-121 |
Author for correspondence:
Theodosios Bisdas, MD, PhD, FACS
Clinic of Vascular Surgery, Athens Medical Center
Kifisias 56, GR-15125, Maroussi, Greece
E-mail: th.bisdas@gmail.com
ISSN 2732-7175 / 2024 Hellenic Society of Vascular and Endovascular Surgery Published by Rotonda Publications
All rights reserved. https://www.heljves.com
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To describe a novel technique for in-situ fenestration (ISF) of the Nexus aortic arch device using the BeBack re-entry catheter in patients contraindicated for total supraaortic debranching.
ISF was performed in four high-risk patients with aortic arch aneurysms, including post-type A dissections, mega-aorta syndrome, and symptomatic endoleaks. Contraindications for total debranching included prior neck surgeries, radiation therapy, and complex anatomy. The procedure involved controlled fenestration of the Nexus graft, deployment of bridging stent-grafts, and restoration of left subclavian artery perfusion.
Technical success was achieved in all cases, with no major adverse events. Follow-up imaging confirmed the absence of target vessel instability or endoleak in two patients at two years, with ongoing stable outcomes for others.
ISF with the BeBack catheter is a safe and effective alternative for urgent aortic arch repair in patients ineligible for total debranching. Larger studies are warranted to validate these findings.
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INTRODUCTION
The endovascular repair of aortic arch aneurysms has emerged as a safe and effective treatment strategy for selected patients, offering a minimally invasive alternative to open surgery, particularly for high-risk individuals1. Over the years, several custom-made devices with varying design concepts-such as outer and inner branches, two or three inner branches, and large fenestrations-have been developed to address this complex anatomical region2, 3. However, a direct comparison of these devices’ effectiveness has yet to be undertaken, leaving the selection largely dependent on the user’s experience and expertise.
For urgent cases requiring treatment up to zone 0 of the aortic arch, the Nexus device (Endospan, Herzlia, Israel) remains the only off-the-shelf endograft specifically designed for this purpose4. While the single-branch design is advantageous for rapid deployment, it necessitates a total supraaortic debranching, typically involving a bypass connecting the right carotid, left carotid, and left subclavian arteries. However, in our clinical experience, certain patients present anatomical or clinical challenges that make total supraaortic debranching infeasible or contraindicated.
To address these limitations, we developed and standardized an in-situ fenestration technique for the Nexus device using a reentry catheter. This approach avoids total aortic debranching while maintaining perfusion to critical vessels. Herein, we present the details of this novel technique.
DESCRIPTION OF THE TECHNIQUE
All patients were treated under general anesthesia, with both the bypass and endovascular repair performed during the same session. After sterile preparation of the surgical field, the left common femoral vein was accessed to insert a central venous catheter for anesthetic monitoring.
A left common carotid-to-left subclavian artery bypass was performed using a thin-walled 8mm ring-armored polytetrafluoroethylene (PTFE) graft (Artivion, NW Kennesaw, USA), following the standard technique as described elsewhere5. The wound was partially closed to allow further access for subsequent procedural steps.
1. Right/left Common Femoral Artery: A surgical cut-down was performed to expose the right or left common femoral artery and bifurcation for device introduction. Ultrasound-guided puncture of the retrograde common femoral vein facilitated the placement of a temporary pacemaker in the right ventricle.
2. Right Brachial Artery: Ultrasound-guided puncture was performed, and a 7F short sheath was introduced for guidewire access.
3. Left Axillary Artery: The left axillary artery was surgically exposed, and a 7F sheath was introduced to facilitate the in-situ fenestration.
A through-and-through guidewire was established between the surgically exposed right or left common femoral artery and the right brachial artery. A pigtail catheter was placed in the proximal ascending aorta for the initial angiogram. A 24F, 65cm Dryseal sheath (W.L. Gore, Arizona, USA) was advanced to the proximal descending aorta and the aortic arch component of the Nexus device was deployed under fluoroscopic guidance4.
A double-curved Lunderquist guidewire (COOK Medical, Bloomington, USA) was carefully advanced into the left ventricle and the ascending graft was introduced and deployed using rapid pacing. Finally, a kissing balloon technique was applied at the docking site using an Expand balloon (Artivion, NW Kennesaw, USA) and a 12mm balloon catheter through the through-and-through wire for the branch of the brachiocephalic artery.
Step 1: A Rosen wire (COOK Medical, USA) was introduced through the pigtail catheter in the left brachial artery and positioned outside the ascending aorta graft. The 7F sheath in the left axillary artery was replaced with an 8F, 45 cm Flexor sheath or a 12F Flexor sheath (COOK Medical, USA), depending on the size of the bridging stent-graft. The sheath was delivered at the level of the origin of the left subclavian artery.
Step 2: Using a Spartacore guidewire (Boston Scientific, Massachusetts, USA) and the BeBack re-entry catheter (Bentley, Hechingen, Germany), the in-situ fenestration was performed as follows: The tip of the BeBack catheter was confirmed in left and right oblique fluoroscopic views to ensure accurate positioning (at 12 o’ clock in the right oblique view). The needle was safely advanced through the polyester graft, and the guidewire was navigated into the descending aorta by rotating the needle.
The fenestration was sequentially dilated with a 3×40 mm Nanocross Elite balloon catheter (Medtronic, Santa Rosa, USA), followed by a 5×60 mm Sterling balloon catheter (Boston Scientific, Massachusetts, USA). Finally, an 8mm VBX stent-graft (W.L. Gore, Arizona, USA) was deployed through the fenestration, and a 10×20 mm balloon catheter was used to flare the stent-graft at the level of the Nexus graft. The completion angiogram confirmed proper perfusion and positioning, and if necessary, the VBX stent was extended using a Viabahn stent-graft.
CASE PRESENTATION
The described technique was performed in four patients undergoing urgent repair of aortic arch aneurysms. All patients provided informed consent prior to the procedure.
Case 1: Post-type A dissection thoracoabdominal aortic aneurysm, complicated by uncontrolled arterial hypertension due to a collapse of the true lumen at the level of the proximal descending aorta.
Case 2: Extensive symptomatic type Ia endoleak following previous endovascular thoracoabdominal aortic repair. Additionally, the patient exhibited further aneurysmal degeneration of the aortic arch.
Case 3: Symptomatic 7.8 cm post-type A dissection aneurysm of the proximal descending aorta. The aneurysm was characterized by rapid enlargement of the false lumen (>2 cm within 6 months).
Case 4: Mega aorta syndrome, presenting with a symptomatic 8 cm thoracoabdominal aortic aneurysm and a concurrent 5.5 cm aneurysm of the aortic arch.
| Patient | Indications for ISF | Type of BSGs |
|---|---|---|
| Patient 1 | Previous thyroidectomy with left vocal paresis | 8mm VBX stent-graft |
| Patient 2 | Previous neck radiation due to tongue cancer | 8mm VBX stent-graft with Viabahn extension |
| Patient 3 | Large asymptomatic goiter | 8mm VBX stent-graft |
| Patient 4 | Previous surgical repair of a right common carotid artery aneurysm | 8mm VBX stent-graft with Viabahn extension |
OUTCOMES
The procedure demonstrated 100% technical success. None of the patients experienced any major adverse cardiovascular events postoperatively. Two of the four patients have completed one-year, and two patients two-year follow-up with computed tomography angiography (CTA) confirming the absence of target vessel instability or other complications.
DISCUSSION
This study presents the first description of in-situ fenestration of the single-branch Nexus One aortic arch endograft using the BeBack re-entry catheter. This novel approach provides a significant advantage by avoiding total aortic arch debranching, a procedure that is not only technically demanding but also contraindicated in certain patient populations.
In our experience, absolute and relative contraindications to total arch debranching include previous carotid endarterectomy, history of surgical procedures involving the esophagus or neck (e.g., oncological surgery, prior radiation therapy), conditions such as dysphagia, previous tracheotomy, or vocal cord paresis, presence of previous carotid artery stenting and severe gastroesophageal reflux disease. For these patients, in-situ fenestration provides an effective and less invasive alternative for restoring supra-aortic vessel perfusion.
Technical Advantages:
- The BeBack catheter is a combined support and re-entry catheter available in two sizes (2.4F and 4F), featuring a front-facing needle
- Enhanced flexibility, particularly in challenging aortic arch anatomies such as Type III arches
- Precise control of needle direction, enabling safe and accurate navigation
- Splits the fibers rather than burning them (unlike laser techniques), potentially preserving structural integrity
Technical Challenges:
- Fenestration Positioning: Accurately locating the fenestration site can be difficult. The optimal site is in the “valley” immediately distal to the single branch
- Sheath Delivery: After fenestration, the 7F sheath must be advanced through the fenestration to allow for safe deployment
- “Swallowing Technique”: To advance the sheath, the 5mm 0.014 balloon catheter is acutely deflated, avoiding the use of a sheath dilator
CONCLUSIONS
This study introduces a novel technique for in-situ fenestration of the Nexus aortic arch device, providing an alternative solution for patients who are ineligible for total supraaortic debranching. The technique offers significant clinical advantages, including the ability to perform both bypass and endovascular repair during a single session, which is particularly critical in urgent cases.
Our initial experience in four patients demonstrates that the approach is both feasible and safe, achieving 100% technical success with no major adverse cardiovascular events. Early follow-up imaging confirmed stable outcomes, with no evidence of target vessel instability or endoleak. However, while these results are promising, further evaluation in larger patient cohorts with long-term follow-up is necessary to validate the technique’s durability, clinical outcomes, and broader applicability.