Case report: Surgical management of type 2 aortic dissection associated with bicuspid aortic valve and aortic coarctation

Abstract

This case report describes an exceptional case of aortic aneurysm co-occurring with type II dissection, bicuspid aortic valve, and severe aortic valve regurgitation in a patient with aortic coarctation. A 39-year-old man without any medical history was admitted to the hospital with chest pain. Physical examination revealed a holosystolic murmur and a noticeable blood pressure difference between the upper and lower extremities. Imaging studies unveiled the presence of aortic dissection, aortic coarctation, and a bicuspid aortic valve. The patient underwent an urgent single-stage surgical intervention performed via a median sternotomy approach: the procedure involved patch angioplasty, a mechanical prosthetic valve, and a Dacron tube graft. The patient’s follow-up assessments indicated successful outcomes. This case report highlights the complexity of managing concurrent pathologies, suggests a unique surgical approach, and underscores the importance of tailored interventions in rare presentations of cardiovascular diseases.

Introduction

Roughly half of individuals with bicuspid aortic valve (BAV) exhibit an enlargement of the ascending aorta, predisposing to dissection. ¹

Aortic coarctation (CoA) coexisting with BAV is relatively common. Existing literature indicates that these concurrent pathologies are commonly treated with multi-phase surgical interventions. ² Interventions prioritizing the resolution of the CoA and the restoration of the aortic arch are typically executed through a left-posterolateral thoracotomy approach.

However, an atypical presentation involving acute aortic dissection alongside significant uncorrected CoA and BAV necessitates immediate dissection management.

Case presentation

A 39-year-old man, without any medical history, was admitted with severe sharp chest pain and dyspnea. These symptoms had begun 2 days before admission as silent chest pain. He came to our hospital when these symptoms increased in intensity and became present with any sort of minimal effort, and he started to feel uneasy. An audible holosystolic murmur across the precordium was accompanied by a global decrease in lung sounds, and coarse crackles were revealed. There was a noticeable difference in blood pressure between the lower (130/81 mmHg) and upper extremities (173/96 mmHg), pointing toward aortic dissection.

Chest X-ray showed rib notching and a prominent aortic knob. Thorax computed tomography (CT) angiography disclosed a DeBakey type II dissection and CoA at the origin level of the common carotid and left subclavian arteries. The largest segment of the dissected ascending aorta was 88 mm in diameter, and the caliper of the aorta was 11 mm at the coarctation site (Figure 1). Both internal mammary arteries were dilated, and multiple intercostal collaterals were identified. A 3D reconstruction depicted the coarctation and the dissection plane (Figure 2). Transthoracic echocardiography showed a BAV with severe aortic regurgitation.

Figure 1.

Thorax CT angiography. (a) Axial. (b) Coronal imaging discloses type II dissection (white arrow), dilated and elongated IMA (white arrowhead).

CT: computed tomography; IMA: internal mammary arteries.

Figure 2.

The 3D reconstruction demonstrates the dissection plane (black arrowhead).

As our primary objective was to correct type II aortic dissection as soon as possible, we decided to evaluate whether we could also correct the coarctation in the same session to achieve a better hemodynamic situation in the postoperative period.

We decided to employ a median sternotomy. The branches of the aortic arch, right pulmonary artery, and multiple enlarged collateral arteries were explored in this area to reach the normal segment of the proximal descending aorta. Then, cardiopulmonary bypass was initiated, utilizing the right axillary and the right femoral arteries, and the right atrium cannulated to ensure uniform perfusion of the body during the correction of coarctation. An additional incision was not used. While we instituted CPB, both lungs were deflated. So we did not face serious difficulty in the repair of coarctation.

A gradual cooling was commenced, and the aortic arch proximal to the left subclavian artery and descending aorta just distal to approximately 30 mm of the coarctated aortic segment was X-clamped to intervene the coarctation safely. Dacron patch angioplasty was performed through an incision extending from the left subclavian artery to the descending aorta. During this procedure, lower body, cerebral, and right upper extremity perfusion were continued via the cannulations mentioned above.

After the correction of coarctation and all arterial clamps were taken off, we passed to the second stage, putting the cross clamp on the distal ascending aorta just proximal to the innominate artery; we verified the radiological findings in operation and saw that extension of dissection was limited to only 2–3 cm proximal part of ascending aorta. The distal ascending aortic segment not affected by dissection was cross-clamped, and continuous retrograde cardioplegia was instituted. The ascending aorta and BAV were totally excised with the preservation of coronary buttons. Commissure between the right and noncoronary cusps of the aortic valve was fused (type 2), and valve mobility and opening were restricted. That is why we did not consider a valve-sparing operation. The transverse 2 cm intimal tear was nearly 5 mm above the aortic annulus. A St. Jude medical size 25 valve prosthesis and a 30 mm Dacron tube graft was implanted in the Bentall procedure (Figures 3 and 4).

Figure 3.

Surgical view captured through median sternotomy, showcasing aneurysmatic and dissected aortic arch.

Figure 4.

Surgical view showcasing aortic arch replacement performed using a Dacron tube graft.

The postoperative course in the intensive care unit progressed without complications. The patient was discharged on postoperative day 8. A follow-up CT scan showed satisfactory repair, and no aortic valve insufficiency was observed on outpatient echocardiograms.

Discussion

Patients with BAV face an estimated six-fold increased risk of type II aortic dissection compared to the general population. ³ BAV is associated with CoA as an aortopathy. The combination of BAV and CoA renders them more susceptible to the development of aneurysms and dissections compared to individuals with BAV alone. ⁴

We found out that in two cases very similar to our patient with acute dissection in the ascending aorta in the presence of CoA, the preferred two-stage approach is changing according to the patient’s clinical status and facilities of the center to reach the team experienced in invasive procedures to correct the CoA. CoA was relieved just before aortic surgery in one of these cases to facilitate femoral cannulation and alleviate the patient’s hemodynamic status. ⁵ The second case is a 16-year-old girl in the same condition who underwent aortic valve and ascending aorta replacement in the first stage, and 3 months after that treatment, she was treated for CoA in another center as the first center had no experience in this field.^6,7 In a 13-year-old boy with a similar condition following ascending aortic replacement, extra-anatomic bypass from the ascending aorta to supracoeliac abdominal aorta inside the pericardium was performed to alleviate the hemodynamic effects of CoA in one stage surgery. ⁸

The single-stage surgical intervention employing the sternotomy approach is a more challenging requirement for suturing deep distal to the coarctation site from the midline.

Nevertheless, comprehensive arch replacement is a secure surgical option for this age when antegrade cerebral perfusion is used. We did not consider procedures such as aortic arch replacement and elephant trunk because, in our patient, the aortic arch, distal ascending aorta, and descending aorta were relatively preserved and looked normal. Alternatively, we could perform an extra-anatomic bypass inside the pericardium to address the CoA. However, we preferred patch angioplasty to correct the CoA and solve the problem in one stage.

Conclusion

BAV and CoA accompanied by dissection are rare occurrences. Anatomical challenges may further complicate this complex scenario. Although two-stage procedures proved to be effective and logical in most cases, when we insist on solving the pathology in one session, we can also consider patch angioplasty to correct CoA in addition to procedures like Bentall or ascending aortic replacement with a graft.