Development of a Branched Stent-Graft for Endovascular Repair of Aortic Arch Aneurysms

The Development of Totally Percutaneous Aortic Arch Repair With Inner-Branch Endografts: Experience From 2 Centers

OBJECTIVE

The main objective of this study is to present the experience of 2 centers undertaking total percutaneous aortic arch-branched graft endovascular repair using combination of femoral and axillary routes. The report summarizes the procedural steps, outcomes achieved, and the benefits of this approach, which eliminates the need for direct open surgical exposure of the carotid, subclavian, or axillary arteries, thereby reducing the unnecessary associated surgical risks.

METHODS

Retrospectively collected data of 18 consecutive patients (15M:3F) undergoing aortic arch endovascular repair using a branched device between February 2021 and June 2022 at 2 aortic units. Six patients were treated for a residual aortic arch aneurysm following previous type A dissection with size range of (58-67 mm in diameter), 10 were treated for saccular or fusiform degenerative atheromatous aneurysm with size range of (51.5-80 mm in diameter), and 2 were treated for penetrating aortic ulcer (PAU) with size range of (50-55 mm). Technical success was defined as completion of the procedure and satisfactory placement of the bridging stent grafts (BSGs) in the supra-aortic vessels percutaneously including the brachiocephalic trunk (BCT), left common carotid artery (LCCA), and left subclavian artery (LSA) without the need for carotid, subclavian, or axillary cut down. The primary technical success was examined as primary outcome well as any other related complications and reinterventions as secondary outcomes.

RESULTS

The primary technical success with our alternative approach was achieved in all 18 cases. There was one access site complication (groin haematoma), which was managed conservatively. There was no incidence of death, stroke, or cases of paraplegia. No other immediate complications were noted. Postoperative imaging confirmed supra-aortic branch patency, with satisfactory position of the BSGs and immediate aneurysm exclusion except in 4 patients who had type 1C endoleak (Innominate: 2, LSA 2) detected on the first postoperative scan. Three of them were treated with relining/extension, and 1 spontaneously resolved after 6 weeks.

CONCLUSIONS

Total percutaneous aortic arch repair with antegrade and retrograde inner-branch endografts can be performed with promising early results. Dedicated steerable sheaths and appropriate BSG would optimize the percutaneous approach for aortic arch endovascular repairs.

CLINICAL IMPACT

This article provides an alternative and innovative approach to improve the minimally invasive techniques in the endovascular treatment of the aortic arch conditions.

Thoracic endovascular aortic repair: are we approaching total endovascular solutions for thoracic aortic disease?

Thoracic endovascular aortic repair (TEVAR) has become an attractive alternative treatment option for thoracic aortic disease. New devices and advanced image-guided procedures are continuously expanding the indications. This article focuses on currently available endovascular solutions for thoracic aortic disease and future 'all endovascular' directions of TEVAR. Currently available endovascular solutions, such as hybrid operations, chimney stent grafting and transapical stent graft deployment, for ascending aortic pathologies are presented. Additionally, the impact of upcoming new technologies, such as endovascular treatment of Stanford Type A dissections of the ascending aorta, is elaborated. With improving device technology, diverse available stent grafts and imaging modalities, TEVAR has become safer and holds promising potential to expand treatment options, especially for the ascending aorta and the aortic arch.

Surgically relevant aortic arch mapping using computed tomography

BACKGROUND

Recent advances in surgical repair of aortic arch pathologies have increasingly used endovascular stent-graft technology. The purpose of this study was to map the aortic arch diameters, branch orientations, and center line distances using a commercially available three-dimensional computed tomography-based software package and to propose a prototype design.

METHODS

TeraRecon 3D imaging software was used for morphological assessment of computed tomography scans from 45 patients (mean age: 68 years; 26 males, 19 females). In each patient, 13 measurements were made in relation to the center line, including diameters at several preset points, distances, and branch vessel orientations.

RESULTS

The mode of the proximal diameters (2 cm and 4 cm distal to coronary artery) was 32 mm and 34 mm. The mode of the distance between the innominate and left common carotid arteries was 5 mm and 6 mm, and the mode of the distance between the left common carotid artery and left subclavian artery was 8 mm. Most commonly, the left common carotid artery was anterior to the other arch branches by 3 to 5 mm.

CONCLUSIONS

These anatomic measurements provide useful information for the advancement of minimally invasive and safer surgical repair of the aortic arch. Based on the most commonly observed measurements, a standardized off-the-shelf stent-graft is proposed that would be appropriate for the majority of patients.

Development of in vivo quantitative geometric mapping of the aortic arch for advanced endovascular aortic repair: feasibility and preliminary results

PURPOSE

To evaluate whether quantitative characterization of aortic arch geometry including its branches is feasible based on in vivo computed tomography (CT) angiography and magnetic resonance (MR) angiography data in healthy and diseased aortic arches.

MATERIALS AND METHODS

Ten healthy volunteers, 10 patients with abdominal aortic disease, and 10 patients with aortic arch disease underwent MR angiography (10 volunteers) or CT angiography (20 patients). Commercial software was used for individual segmentation of supraaortic arteries. In-house software was developed for segmentation of aortic arch landmarks based on standardized multiplanar reformations (MPRs) and for subsequent aortic arch mapping.

RESULTS

Supraaortic arteries and aortic arch landmarks were successfully segmented in all 30 subjects for CT angiography and MR angiography data. Significant tapering within the first centimeter was observed in all supraaortic arteries (P < .001). The three supraaortic arteries showed significantly different vessel diameters and areas (P < .001). The software developed in-house allowed detailed aortic arch mapping with quantitative definitions of the positional relationships between each supraaortic artery and the aorta. Distances between supraaortic arteries were less than 5 mm in 77.6% (mean 4.1 mm ± 3.8). The brachiocephalic trunk tended to be positioned on the right side of the aortic arch, and the left subclavian and left common carotid arteries tended to be positioned on the left side of the aortic arch.

CONCLUSIONS

The feasibility and application of a postprocessing method allowing quantification of geometry of supraaortic arteries and aortic arch mapping were successfully demonstrated. Validation and evaluation of clinical implications are warranted.

Hybrid endovascular repair in aortic arch pathologies: a retrospective study

The aortic arch presents specific challenges to endovascular repair. Hybrid repair is increasingly evolving as an alternative option for selected patients, and promising initial results have been reported. The aim of this study was to introduce our experiences and evaluate mid-term results of supra aortic transpositions for extended endovascular repair of aortic arch pathologies. From December 2002 to January 2008, 25 patients with thoracic aortic aneurysms and dissections involving the aortic arch were treated with hybrid endovascular treatment in our center. Of the 25 cases, 14 were atherosclerotic thoracic aortic aneurysms and 11 were thoracic aortic dissection. The hybrid repair method included total-arch transpositions (15 cases) or hemi-arch transpositions (10 cases), and endovascular procedures. All hybrid endovascular procedures were completed successfully. Three early residual type-I endoleaks and one type-II endoleak were observed. Stroke occurred in three patients (8%) during the in-hospital stage. The perioperative mortality rate was 4%; one patients died post-operatively from catheter related complications. The average follow-up period was 15 ± 5.8 months (range, 1–41 months). The overall crude survival rate at 15 months was 92% (23/25). During follow-up, new late endoleaks and stent-raft related complications were not observed. One case (4%) developed a unilateral lower limb deficit at 17 days and was readmitted to hospital. In conclusion, the results are encouraging for endovascular aortic arch repair in combination with supra-aortic transposition in high risk cases. Aortic endografting offers good mid-term results. Mid-term results of the hybrid approach in elderly patients with aortic arch pathologies are satisfying.

The Aortic Arch and Ascending Aorta: Are They Within the Endovascular Realm?

Aneurysms involving the ascending aorta and arch have been historically treated with open surgical techniques requiring cardiopulmonary bypass and, in cases involving the aortic arch, utilizing deep hypothermic circulatory arrest. The reported rates of mortality range from 0% to 16.5% for surgery addressing ascending aorta and arch pathology, and stroke rates of 2% to 18%. These statistics highlight the invasiveness of these procedures. Continued development and evolution of endovascular stent-grafts has allowed for the application of endovascular interventions in the proximal descending thoracic aorta and visceral aortic segments. Based on early experiences, attention has been focused on the ascending aorta and aortic arch, where unique challenges exist and have been addressed by both extra-anatomic bypass and novel methods incorporating branched and fenestrated devices. Device evolution, coupled with increased experience by the aortic interventionalist, has resulted in successful cases of endovascular management of every section of the aorta, including aortic valve replacement. However, these experiences have also been accompanied by significant complications. In this light, new endovascular endeavors must be considered in the context of conventional treatment options, hybrid procedures, and novel branched devices. Patient factors, such as specific anatomic issues, comorbid diseases, and functional levels must play an important role in the determination of therapeutic options. Ultimately, a clinician who understands the disease and is familiar with all treatment options (interventional, medical, and open surgical) will be best suited to provide care for the aortic patient. Finally, as with any assessment of interventional strategies, rigorous follow-up and serial imaging are essential.

The Hybrid Total Arch Repair: Brachiocephalic Bypass and Concomitant Endovascular Aortic Arch Stent Graft Placement

BACKGROUND

Repair of aortic arch aneurysm is technically demanding, requiring complex circulatory management. Very large atherosclerotic saccular aneurysms of the arch are grave markers of extensive arch and brachiocephalic atheromatous disease and represent high surgical risks for perioperative neurologic complications. Operative morbidity and mortality may be prohibitive with traditional surgical intervention. We described our experience with a hybrid procedure for total arch repair with a brachiocephalic bypass with a trifurcated graft followed by concomitant placement of a stent graft in the arch.

METHODS

Since June 2005, we have performed the hybrid total arch repair in eight patients. A retrospective review was performed to evaluate the new technique.

RESULTS

The mean age of the patients was 67 years with a mean aneurysm size of 8 cm (range, 4.4 to 10 cm). Significant comorbidities included carotid stenosis, chronic renal insufficiency, peripheral vascular disease, hypertension, and coronary artery disease. Two patients had previous Abdominal aortic aneurysm (AAA) repairs. Three patients had previous sternotomy for type A dissection, ascending aortic aneurysm repair, and coronary artery bypass grafting. Transesophageal echocardiogram demonstrated grade IV or V atheromatous disease in the arch and ascending aorta. Stent grafts were deployed antegrade directly into the ascending aorta in three patients and retrograde from the femoral artery in five patients. Technical success with complete aneurysmal exclusion was achieved in all patients (100%). At a mean follow-up period of 11.7 months, there was no incidence of endoleak. There was one death resulting from a perioperative myocardial infarction (first patient). Documented perioperative neurologic events (stroke) occurred in two patients, with both patients demonstrating no residual deficit at the time of discharge.

CONCLUSIONS

Saccular arch aneurysms can be technically treated by total arch repair with brachiocephalic bypass and concomitant aortic arch stent graft placement. Hybrid arch repair provides an alternative to patients otherwise considered prohibitively high risk for traditional open arch repair.

Extended Applications of Thoracic Aortic Stent Grafts

BACKGROUND

Thoracic stent-grafts (TSG) show excellent early and mid-term results for localized diseases of the descending aorta. Extending TSG applications for arch pathologies or to other yet unproven indications remains to be established. We herein report our experience in 18 patients with extended applications of TSG.

METHODS

Ten patients with inadequate proximal aortic neck length required coverage of at least one arch vessel with or without extra-anatomic bypass. One patient required an extra-anatomic visceral bypass to extend the distal aortic neck, 6 patients were treated with TSG for yet unproven indications, and 1 patient required an unusual vascular access.

RESULTS

A mean of 2.4 +/- 1.0 stents per patient were inserted. Primary or secondary success rate was 100%. Hospital mortality occurred in one patient (5.5%). Mean follow-up was 24.1 +/- 13.7 months. Four endoleaks were diagnosed: two of type 1, one of type 2, and one that remains undetermined. Two patients died during follow-up; both deaths were linked to the presence of a type 1 endoleak. Actuarial survival at 3 years was 79.0%. Freedom from endoleak and stent-graft-related death at 3 years were, respectively, 71.0% and 83.7%. No stent-graft migration was observed.

CONCLUSIONS

Early and mid-term results of extended applications of TSG are acceptable in well-selected high-risk patients. Endoleak at follow-up remains a concern and may impede long-term outcome of TSG in complex procedures.

Stent-Graft Repair of Thoracic Aortic Aneurysms

Endovascular treatment of aortic disease has emerged as an alternative mode of treatment that is particularly attractive for patients with severe comorbidities who would not be ideal candidates for open surgery. Actually, short-term morbidity and mortality rates, of large series, compare favorably with those from surgery, and stent-graft placement is proving to be a safe, minimally invasive, and effective treatment for thoracic aortic diseases. However, although endoluminal interventions are minimally invasive, they are associated with complications, as are surgical methods. In this article, indications, technical aspects, and results of endovascular TAA repairs will be reviewed. We will also examine the advantages and limitations of stent-graft treatment. Finally, we will discuss the management of complications following aortic stent-graft implantation. We intentionally do not cover the topic of thoracic dissection, as it is being covered in another article in this volume.

Suprarenal stents and other advances in endovascular aneurysm repair

The history of endovascular aneurysm repair has already passed through its phases of "endoexuberance" and "endoscepticism" and there is now a balanced and broad understanding of the technology,its limits and advantages. Current endovascular technique and stent-graft design is the refinement of the accumulated endovascular experience til now. It is important to make note of these technological features incorporated in current stent-grafts and the clinical experience that precipitated their introduction as the technology progresses and new applications are proposed.

In Situ Stent-Graft Fenestration to Preserve the Left Subclavian Artery

PURPOSE

To report our first clinical application of a new technique for in situ fenestration of a thoracic stent-graft.

CASE REPORT

After completing a series of in vitro and in vivo experiments, in situ stent-graft fenestration was employed during endograft repair of a saccular thoracic aortic aneurysm in a 77-year-old woman. Because the stent-graft would have covered the left subclavian artery ostium, a modified Zenith TX1 thoracic stent-graft was deployed then fenestrated transluminally using a guidewire followed by serial cutting balloons, which created a fenestration over the LSA sufficiently large to accommodate a Jomed covered stent on an 8-mm balloon. Completion angiography showed exclusion of the aneurysm and brisk flow into the LSA. Following the procedure, the arm pressures were nearly equal. The 6-month CT scan showed no endoleak and a patent subclavian artery stent.

CONCLUSIONS

In situ graft fenestration to preserve the left subclavian artery after deliberate coverage during endovascular repair of a thoracic aortic aneurysm appears feasible in this initial clinical application. There are uncertainties regarding the long-term stability of the fabric tears that are an inherent part of this technique.