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J Cardiothorac Surg
J Cardiothorac Surg
Journal of Cardiothoracic Surgery
1749-8090
BioMed Central London

3024
10.1186/s13019-024-03024-y
Research
Single-branched stent-graft with on-table fenestration for the management of zone 2 landing TEVAR with an isolated left vertebral artery: a pilot study
Kong Xiang drkongxiang@ustc.edu.cn

Yu Jiquan
Ruan Peng
Ge Jianjun
grid.59053.3a 0000000121679639 Department of Cardiovascular Surgery, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China (USTC), Hefei, China
13 9 2024
13 9 2024
2024
19 52823 7 2023
30 8 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Background

It is challenging to simultaneously conduct total endovascular repair and reconstruct the left subclavian artery (LSA) and isolated left vertebral artery (ILVA) in patients who had an ILVA and required zone 2 anchoring. This pilot study reported the initial application experience of thoracic endovascular aortic repair (TEVAR) with a proximal zone 2 landing for aortic arch reconstruction in patients with ILVA.

Methods

This study was a retrospective consecutive single-center case series analysis, which involved four patients with ILVA who required zone 2 anchoring and received TEVAR combined with a single-branched stent graft and concomitant on-table fenestration between March 2021 and December 2022.

Results

The postoperative follow-up period was 6–27 months, and no postoperative deaths or other primary complications occurred. There were no signs of a stroke or spinal cord ischemia, as well as no chest or back pain. The postoperative computed tomography angiography showed unobstructed ILVA and LSA, no stent stenosis and displacement, and no signs of endoleak.

Conclusion

The outcome suggested that this technique might be a feasible, safe, and alternative treatment for such patients. Further studies with larger samples and longer follow-up periods are needed to confirm our findings.

Keywords

Thoracic endovascular aortic repair (TEVAR)
Isolated left vertebral artery (ILVA)
Branched stent graft
On-table fenestration
issue-copyright-statement© BioMed Central Ltd., part of Springer Nature 2024
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pmcBackground

The isolated left vertebral artery (ILVA) originates from the aortic arch and is usually located between the left common carotid artery (LCCA) and the left subclavian artery (LSA). It is the second most common congenital anomaly of the aortic arch with an incidence of 1.7 to 4.3% [1]. It is often required to cover LSA and ILVA and establish an adequate proximal landing zone when this aberration is found during thoracic endovascular aortic repair (TEVAR) of aortic arch pathologies. Open revascularization techniques like carotid-subclavian bypass are commonly employed for the treatment of patients with LSA coverage, especially for non-ILVA cases. Improper management of ILVA may result in brain ischemia or infarction [2]. However, due to the limited data obtained from case reports, the optimal treatment for aortic arch diseases combined with ILVA remains unclear. This study reported the treatment effect of TEVAR in patients with ILVA who underwent zone 2 anchoring with a single-branched stent graft and concomitant on-table fenestration.

Methods

It was a retrospective single-center case series study. All patients with aortic arch pathologies who underwent TEVAR between March 2021 and December 2022 were retrospectively evaluated (n = 159). Patients without ILVA (n = 152), patients with ILVA and who received on-table single big fenestration (n = 1), and those following ILVA translocation and LCCA-LSA bypass (n = 1) were excluded from the analysis. Finally, patients following on-table fenestration with the branched stent graft comprised the study cohort (n = 4; Fig. 1). The Institutional Ethics Committee approved the study (IRB number, 2023-RE-123). Participants were not required to provide informed consent due to the retrospective nature of this study. All patients underwent preoperative computed tomography angiography (CTA) of the aortic arteries. Endosize software (Therenva SAS, Rennes, France) was used to evaluate vertebral artery dominance, ILVA diameter, aortic arch type and pathology, the distance between ILVA and LSA, location of the primary entry tear, maximum aortic diameter, and true or false lumen. The aortic reconstruction was completed with CTA in a central-line protocol mode.

Fig. 1 Flow diagram for the enrollment of patients treated by TEVAR with a proximal zone 2 landing Note TEVAR, thoracic endovascular aortic repair; ILVA, isolated left vertebral artery

This study used the Castor stent (MicroPort Endovascular, Shanghai, China) as a novel unibody single-branched stent with on-table fenestration for endovascular repair of the aortic arch (Fig. 2). Acute type B aortic dissection (AD) patients were treated with medications to control their blood pressure and heart rate. Surgery was performed at least one week after the onset of acute AD when the clinical condition was stable. All procedures were performed in a conventional supine position under general anesthesia and were given 1.5 g of intravenous cefuroxime sodium 30 min before surgery to prevent surgical infection. The systemic heparin was administered at 100 IU/kg after the percutaneous arterial puncture. The stent was 5 to 10% oversized the maximum diameter of the true lumen in zone 2 (Fig. 3). The proximal part of the Castor stent was released out of its outer sheath at the operating table. An on-table fenestration was made to preserve the ILVA. The location and size of the fenestration were determined based on the preoperative aortic CTA measurement. The coating part of the stent was excised with a surgical blade for on-table fenestration (Fig. 4). The Castor stent was inserted into the delivery system and should avoid being distorted and shortened.

Fig. 2 Schematic diagram of surgery. Castor stent as a novel unibody single-branched stent with on-table fenestration for endovascular repair of the aortic arch. Note BT, brachiocephalic trunk; LCCA, left common carotid artery; LSA, left subclavian artery; ILVA, isolated left vertebral artery; TL, true lumen; FL, false lumen

Fig. 3 ILVA originating from the aortic arch by preoperative CTA. (A) Transverse plane; (B) Coronal plane; (C) 3D reconstruction model. Note BT, brachiocephalic trunk; LCCA, left common carotid artery; LSA, left subclavian artery; ILVA, isolated left vertebral artery; TL, true lumen; FL, false lumen

Fig. 4 On-table fenestration of the Castor stent graft. A Castor branched stent graft; B The outer sheath was released; C The proximal part of the Castor stent was released out of its soft sheath; C An on-table fenestration was made to preserve the ILVA. Note ILVA, isolated left vertebral artery

The detailed operation of the Castor stent was described earlier [3]. The right femoral artery (RFA) was exposed through a right inguinal incision. The left femoral artery (LFA) and left brachial artery (LBA) were punctured to insert the 6 F sheath. A contrast catheter was inserted into the ascending aorta through the RFA. The diagnosis was confirmed by angiography and preoperative imaging data. The access at LBA and RFA was established to ensure the successful insertion of the catheter in the true lumen of the aorta. A 0.035-inch super-stiff guidewire (Amplatz, Olympus, USA) was inserted into the ascending aorta via the RFA. The main body of the Castor stent was introduced through the super stiff guidewire, and its branch section was introduced into LSA through the access at LBA and RFA. A contrast catheter was placed into the ascending aorta through the sheath in the LFA to confirm that the proximal end of the main body of the Castor stent was located at the posterior edge of the LCCA ostium and that the branch section was pulled into the LSA. The medication treatment was used to maintain the patient’s systolic blood pressure at around 90 mmHg for the deployment of the main body. The main body and the branch section were released successively (Fig. 5). The angiography catheter was sent to the ascending aorta again. After the angiography confirmed a satisfactory position of the stent, the delivery system, guide wires, and catheters were withdrawn, and the puncture sheath was removed. The incisions at RFA and right groin were sutured. Hemostasis was achieved by pressing the LFA and LBA puncture sites. After surgery, the patients was treated with 100 mg of aspirin once a day for one year. The aortic CTA was performed six, 12, and 24 months postoperatively. All patients underwent physical examination one month after surgery and were followed up until June 2023.

Fig. 5 Successful reconstruction of LSA and LVA confirmed by intraoperative angiography and postoperative CTA. A Intraoperative angiography demonstrated type B aortic dissection and the origin of ILVA from the aortic arch between LCCA and LSA before stent-graft insertion; B Intraoperative angiography revealed that the branch section of the Castor stent was pulled into the LSA; C Intraoperative angiography revealed complete coverage of the primary tear of the aortic dissection without endoleak and normal flow of ILVA and LSA after the Castor stent release; D 3D-CTA showed the patency of ILVA and LSA and the favorable revascularization of aorta arch without endoleak at the three-month follow-up. Note LCCA, left common carotid artery; LSA, left subclavian artery; ILVA, isolated left vertebral artery; TL, true lumen; FL, false lumen; 3D-CTA, 3-dimensional computed tomographic angiography

Results

Between March 2021 and December 2022, four patients in our center, including three cases of acute aortic dissection and one of aortic aneurysm, underwent ILVA and LSA reconstruction using a single-branched stent graft with the on-table fenestration technique. Their preoperative data are shown in Table 1. The mean age of the patients was 62.8 ± 15.3 years (range, 48–76 years). The total time for creating the on-table fenestration (unsheathing and re-sheathing of the thoracic endograft) was about 20 to 30 min. The mean operation time was 118 ± 21.3 min (range, 91–141 min). The technical success rate (defined as ILVA patency) was 100%. The mean postoperative length of hospital stay was 9.8 ± 5.7 days (range, 3–14 days). Intraoperative angiography confirmed complete isolation of the primary entry tear and ILVA and LSA patency. The postoperative follow-up period was 6–27 months, with an average of 15.8 ± 9.9 months. No postoperative deaths or other primary complications occurred. Besides, there were no stroke or spinal cord ischemia symptoms and no further chest and back pain. One postoperative patient refused to undergo CTA due to renal insufficiency. The postoperative CTA of other patients showed patent ILVA and LSA, false lumen thrombosis, no stent stenosis or displacement, and no signs of endoleak (Fig. 4).

Table 1 Patient’s characteristics

Case	Gender	Age	Etiology	Type of arch (Myla)	Surgical indication	DPL (mm)	ID (mm)	Operation time(min)		
1	male	78	Acute type B AD	3	intractable pain	4	4	91		
2	male	74	Aneurysm	2	having symptoms	7	4	127		
3	male	50	Acute type B AD	3	malperfusion	10	3	141		
4	female	49	Acute type B AD	2	intractable pain	3	6	114		
Note DPL, distance from the proximal end of the lesion to the LSA ostium; ID, ILVA diameter; AD, aortic dissection

Discussion

It is difficult to reconstruct LSA and ILVA while performing TEVAR in patients with ILVA requiring zone 2 anchoring. Normal vertebral arteries can form the basilar arteries and supply blood to the cerebellum and brainstem. The prevalence of a complete Willis circle is 42% in the Western population and 27% in Chinese people [4, 5]. ILVA is not associated with any clinical symptoms; however, it may increase the risk of spinal cord injury (SCI) and cerebral infarction after aortic arch surgery. It remains controversial to cover ILVA during TEVAR, and there are no clear guidelines and few relevant reports. If there exists insufficient vascular connection at the Willis circle, covering ILVA may reduce the brain stem or cerebellar perfusion and increase the risk of neurological deficits. Emerging evidence has suggested that a potential reduction in the brain stem or cerebellar perfusion due to VA occlusion could contribute to nerve injury [6, 7].

Previous studies have compared the early and late outcomes of conventional open surgery and hybrid surgery (ILVA translocation and LCCA-LSA bypass) for aortic lesions with ILVA and concluded a favorable effect in both methods [8, 9]. Nevertheless, elderly or high-risk patients might not tolerate median sternotomy and its fatal complications. In contrast, hybrid surgery was less invasive than open surgery and showed mild to moderate complications, including bleeding from the wound, wound infection, bypass obstruction, and local nerve damage. Therefore, total endovascular repair during this procedure might reduce the risk of brain disease, early mortality, and length of hospital stay. Recent guidelines suggested that LSA revascularization should be performed during zone 2 TEVAR with an insufficient anchoring zone in non-emergency patients [10]. The branched stent technique was superior to other methods for LSA reconstruction because it did not cause type Ia (common in chimney technique) and III leakage (common in fenestration technique). The incidence of stent restenosis was high due to the small diameter of ILVA. Therefore, ILVA endograft should be avoided as much as possible. The simultaneous reconstruction of LSA and ILVA using single or double on-table fenestration was a feasible technique for the endovascular repair of ILVA. The cerebral ischemia might occur during traditional on-table fenestration of arch lesions due to misalignment of the fenestration. One prior study found that two patients with dizziness had a partial misalignment of the fenestration to the origin of the ILVA and insufficient blood perfusion of the cerebellum [11]. We successfully applied a novel “Castor” single branched-stent graft with on-table fenestration to optimize the process of endovascular ILVA reconstruction and reduce the risk of cerebral ischemia. In addition to the successful reconstruction of the blood flow of LSA, the anchoring and positioning effects of the branch section could help quickly and accurately determine the fenestration site and avoid the possibility of poor alignment during fenestration. All ILVA patients were confirmed to have accurate alignment by the results of immediate imaging after stent implantation and postoperative CTA, and there were no postoperative brain complications.

Limitations

The study had certain limitations. This was a single-center, retrospective observational study with limited samples and relatively shorter follow-up periods. In addition, this study lacked a control group.

Conclusion

In summary, our study with limited samples suggested that the unibody single-branched stent graft combined with on-table fenestration was a safe, feasible therapeutic for patients with ILVA who required zone 2 anchoring. Nevertheless, our finding needed to be confirmed by further studies with larger samples and longer follow-up times.

Acknowledgements

We acknowledged all the contributions by the participating doctors from our department.

Author contributions

Xiang Kong designed the work and wrote the main manuscript. Jiquan Yu, and Peng Ruan collected and analyzed the patients’ data. Xiang Kong and Jianjun Ge revised the final manuscript. All authors read and approved the final manuscript.

Funding

None.

Data availability

All generated or analyzed data, as well as the materials used during this study were included in this article.

Declarations

Ethical approval

The present study was approved by the institutional review board of The First Affiliated Hospital of University of Science and Technology of China (USTC), Division of Life Sciences and Medicine, USTC. (IRB number, 2023-RE-123). Participants were not required to provide informed consent due to the retrospective nature of this study.

Competing interests

The authors declare no competing interests.

Abbreviations

LSA Left Subclavian Artery

ILVA Isolated Left Vertebral Artery

TEVAR Thoracic Endovascular Aortic Repair

LCCA Left Common Carotid Artery

CTA Computed Tomography Angiography

AD Aortic Dissection (AD)

RFA Right Femoral Artery

LFA Left Femoral Artery

LBA Left Brachial Artery

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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