Hybrid Completion of Aortic Repair after Type A Aortic Dissection in a Patient with Marfan's Syndrome.

Medicine and engineering are in collaboration to assist in the tackling of daunting surgical techniques which are associated with high rates of morbidity and mortality, in exchange for minimally invasive approaches with lower procedural risk. Endovascular procedures in general have already reduced the risk of surgery by limiting the extent of open surgery and often replacing it with purely percutaneous or hybrid procedures. Here, we describe a patient who had complex staged surgery with open repair of a proximal portion of a type A aortic dissection followed by a staged endovascular reconstruction of the arch and descending aorta by means of a fenestrated stent-graft to secure the left subclavian artery and the posterior cerebral circulation.

INTRODUCTION

The management of complex aortic arch pathologies remains challenging, in particular in cases of connective tissue disease such as genetically confirmed Marfan syndrome. In an attempt to fraction the risk burden of major aortic surgery after a type A aortic dissection, open surgery was limited to the ascending aorta, while the distal arch and descending aorta were considered to be a better target for an exclusively endovascular approach. Preservation of the subclavian artery is recommended,[1] particularly in elective cases, and techniques such as in situ fenestrations,[23] chimney,[4] and custom-made fenestrated aortic stent-grafts have been employed to maintain the patency of the subclavian artery in conjunction with thoracic endovascular aortic repair (TEVAR).

Little is known about staged endovascular solutions to address the distal arch and descending aorta in Marfan syndrome after a type A aortic dissection.

CASE PRESENTATION

A 48-year-old male was diagnosed with a Stanford A aortic dissection when he presented to an emergency department with hemodynamic instability and a history of sudden-onset severe chest pain. A computed tomography aortogram (CTA) revealed an acute type A aortic dissection involving the aortic root, arch, and the rest of the aorta down to the left external iliac artery. The dissection flap also extended into the brachiocephalic trunk, left common carotid, and proximal left subclavian artery (LSA). There was complete occlusion of the left internal carotid artery while the right carotid artery supplied the entire anterior circulation through the intact circle of Willis; the posterior circulation was supplied by both vertebral arteries. Swiftly after diagnosis, he underwent emergency ascending aortic replacement and re-suspension of the aortic valve as a first step.

Postoperative surveillance CTA showed progression of the dissection in the left common carotid and LSA and coeliac artery dissection and re-entry into the false lumen of the thoracic aorta from the abdominal aorta [Figure 1]. Magnetic resonance angiography confirmed the findings on the CTA. The initial plan was to replace the aortic arch, however intra-operative assessment prompted deferring the patient to a staged procedure using endovascular technology in conjunction with surgical debranching of the innominate artery and the left common carotid artery using a Y-graft attached to the ascending aorta interposition graft.

Figure 1

Computed tomography aortogram reconstructed image of aorta prior to endovascular procedure, showing the de-branching procedure and the aortic arch and false lumen dilatation

Postdebranching CTA showed good results of the debranching procedure, but subsequent studies showed progressive dilatation of the descending thoracic aorta, and at 6 months, there was an increase in the dimension of the arch of aorta from 44 cm × 47 mm to 44 cm × 52 mm [Figure 1].

In light of these findings, a consensus was made to use a customized stent-graft for reconstructing the dissected and expanding arch segment. There were also concerns that it would be difficult to transpose or bypass the dissected LSA [Figure 1]. A fenestrated aortic stent-graft was custom-made with a side hole to accommodate a side branch stent-graft at the level of the offspring of the LSA. This configuration was chosen to provide both successful sealing and firm lasting aortic reconstruction.

Poststenting of the aorta, the patient had an uneventful postoperative period and was discharged from hospital within 4 days. There was surveillance computed tomography scans up to 4 months after the operation, confirming flow in the LSA and sealing of the entry point in the aorta.

Procedure

In a staged fashion after surgical repair of the proximal aorta, endovascular reconstruction was performed of the aortic arch and descending aorta. A customized 250 mm × 28/26 mm Bolton Medical RELAY stent-graft and a Fluency 12 mm × 40 mm stent-graft were utilized.

Under fluoroscopic control, the fenestrated stent-graft was navigated toward the orifice of the left subclavian; its position was double checked by virtue of metallic markers before deployment. After deployment, the fenestration was then cannulated through the left brachial access using a 0.035 Terumo wire before a Fluency graft was placed through the fenestration into the LSA. For this procedure, access was obtained through the right common femoral artery and the left brachial artery. The right femoral artery was accessed through a cut down, as this was thought to be safer than the percutaneous approach in a patient with an aortopathy and dissection. Since the LSA was also dissected, the true lumen was confirmed using transesophageal echocardiography (TOE) in conjunction with fluoroscopy and injection of contrast.

The patient was heparinized to obtain an activating clotting time of ~ 350. The LSA orifice was confirmed using a balloon catheter [Figure 2] which also served as a marker for positioning of the aortic stent before deployment. Ensuring that the orifice was aligned with the LSA lumen, the aortic stent-graft was deployed under rapid ventricular pacing to decrease blood pressure and avoid a wind-sock effect.

Figure 2

Image of balloon in left subclavian artery and fenestration in aortic stent-graft aligned with left subclavian artery orifice

Guide wires were passed from the lumen of the aorta into the LSA before a covered Fluency stent was placed into the LSA and deployed under fluoroscopy and TOE. Postdeployment of the LSA stent, there was no leakage of contrast from the true to the false lumen in the LSA.

DISCUSSION

We report a case of customized fully interventional repair of the distal arch and the descending aorta in a Marfan patient who underwent previous open repair of his ascending aorta, using a fenestrated aortic stent with an additional side branch for the LSA.

Six months follow-up showed an excellent technical result with re-modeling of the aorta and a markedly improved clinical status. While the classic hybrid approach combines surgical and interventional procedure to minimize the global risk, this example has demonstrated a separate fully endovascular approach by the use of a fenestrated stent-graft with additional side branch stenting for the first time in a Marfan patient. Instead of additional extra-anatomical debranching (transposition or bypass of the LSA) which can be a challenge due to the position of the LSA inside the chest, surgery was entirely avoided in this case.

There are several options for the management of the LSA during aortic stenting; a) covering the orifice of the LSA, an approach not favored by the current guidelines,[1] b) in situ fenestration of the stent-graft,[23] c) or the “chimney” technique.[4] We herein present an uncommon case of a customized stent-graft with an off-the-shelf side branch stent to avoid complex open surgery with well-known associated risk, particularly in Marfan patients. The essential benefit of the fully endovascular technique is of course preservation of antegrade flow to the LSA, the arm and the left vertebral artery which is considered of prognostic importance.

In collaboration with the manufacturer and based on CTA measurements, it was elected to use a customized and individualized stent-graft/side graft stent, a concept to secure LSA flow and avoid re-routing vascular surgery.

Previous series have reported covering of the LSA with or without extra-anatomical revascularization as another option to manage patients whose stent-graft would land in the zone of the LSA. However, with occlusion of the LSA, the patient can develop symptoms, or even stroke from the obstruction of flow to the left vertebral artery. To avoid that risk, we opted for a nonsurgical revascularization strategy by stenting the LSA through a customized fenestrated aortic stent-graft with an orifice to the LSA. The case proved that this concept is successful even in patients with Marfan syndrome.

While both the discharge CTA and follow-up imaging at 6 months showed excellent results [Figure 3], long-term surveillance is still recommended. With the use of three-dimensional imaging, stent-grafts can be custom-made from flexible materials and even be used in patients with hereditary connective tissue disorders in selected cases.

Figure 3

Computed tomography aortogram reconstructed image of the aortic stent-graft and the left subclavian artery stent in situ

CONCLUSION

In conclusion, current technology provides a fully endovascular solution for pathologies such as expanding chronic dissections in the aortic arch regions and descending aorta even in cases of Marfan syndrome. This approach helps to avoid the procedural risks of additional surgical debranching procedures and is likely to provide both aortic remodeling and a durable solution (at least to 1 year) even in patients with hereditary connective tissue disease. In the near future, we even expect to avoid proximal debranching in zone 0, by the use of multi-branched/fenestrated graft components.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.