Bentham Science Logo

New Emirates Medical Journal

Volume 1, 2 Issues, 2020
ISSN: 0250-6882 (Online)
This journal supports open access

Open Access Article

An Aortic “Supravalvular Shelf” is Not Always Innocuous



Laszlo Göbölös1, *, Gurjyot Bajwa1, Jehad Ramahi1, Pier Carlo Bergonzi2, Gopal Bhatnagar1
1 Department of Cardiac Surgery, Heart and Vascular Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, UAE
2 Department of Cardiovascular Intensive Care, Cleveland Clinic Abu Dhabi, Abu Dhabi, UAE

Abstract

Supravalvular aortic stenosis is a rare cause of secondary aortic root distension and/or aortic valve regurgitation. Non-syndromic aortic aneurysms may also occur in young adults and can develop silently, representing an asymptomatic, life-threatening condition. Clinicians should, therefore, be alert to the possibility of this uncommon, but potentially serious disease, often first revealed by an imaging modality requested for other indications, even in case of an established, more benign diagnosis.

Keywords: Aortic valve, Supravalvular membrane, Chronic, Aortic dissection, Aortic root, Pathological changes.


Article Information


Identifiers and Pagination:

Year: 2020
Volume: 1
Issue: 1
First Page: 17
Last Page: 19
Publisher Id: nemj-1-17
DOI: 10.2174/0250688202002021101

Article History:

Received Date: 28/10/2019
Revision Received Date: 26/12/2019
Acceptance Date: 30/12/2019
Electronic publication date: 11/03/2020
Collection year: 2020

© 2020 Göbölös et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to this author at the Department of Cardiac Surgery, Heart and Vascular Institute, Cleveland Clinic Abu Dhabi, Abu Dhabi, PO Box: 112412, United Arab Emirates; Tel: +971-554-313-513; +971-2-501-9000; Ext. 49700; E-mail: isartor@hotmail.com




1. INTRODUCTION

Supravalvular aortic stenosis is a rare congenital cardiac anomaly characterised by a variable degree of left ventricular outflow tract obstruction, originating from just above the aortic valve. Although the proximal aortic root is not primarily involved, it may show secondary pathological changes leading to the development of aortic valve regurgitation and/or coronary ischaemia. Thickening of the tunica media in the aortic wall secondary to excessive collagen deposition and hypertrophied smooth muscle cells leads to the build-up of the obstructive membrane in cases of supravalvular stenosis [1, 2].

Non-syndromic aortic aneurysms are also deemed uncommon in comparison to other cardiovascular conditions in young adults and may represent an asymptomatic, life-threatening condition. Therefore, clinicians should be vigilant in the evaluation of patients, as aneurysms are often first detected incidentally on imaging requested for other indications. Any evidence of an enlarged aorta should trigger further investigations; awareness of aortic aneurysms facilitates the reduction of morbidity and mortality associated with this pathology [3-5].

2. CASE DESCRIPTION

We report the case of a 26-year-old woman who collapsed during her university exam. Her medical history was significant only for morbid obesity (body-mass index of 62 kg/m2). Echocardiography on admission diagnosed severe aortic valve regurgitation with a dilated aortic root and a supravalvular membrane above both the right- and left coronary cusps of the aortic valve Fig. (1A and B). Surgical correction was recommended, however the patient refused to undergo surgery.

One month later, she was re-admitted with acute pulmonary oedema secondary to cardiac decompensation to our hospital. On physical examination and faint soft, decrescendo murmur was detected in the second intercostal space, on Erb’s point, in addition to the bilateral crackles up to the mid-pulmonary zones. Routine blood sampling did not reveal any major pathological changes except mild hypokalaemia and mild iron deficiency anaemia. Chest X-ray showed a bovine heart without any further concomitant pathologies. In addition to the known severe aortic regurgitation, a DVT was diagnosed by ultrasound of the left calf and a chest CT performed to assess for possible PE. Further to a segmental pulmonary embolus within the right upper lobe artery, CT measured a 55 mm aortic root diameter, and a structure consistent with either the supraaortic membrane considered previously from the echo, or the differential diagnostic possibility of a dissection flap was seen in Fig. (1C). No further flaps or false lumen were visible, and the mid-ascending aorta demonstrated a diameter within the normal range. The peak gradient through the aortic valve measured 11 mmHg with a peak velocity of 163 cm/s on Doppler investigation. The aortic regurgitant radius was 1.1 cm, EROA 0.48 cm2, regurgitant jet pressure half time measured 102 ms. The right ventricle was mildly dilated with normal systolic function and a moderated pulmonary hypertension was registered.

Intravenous heparin was commenced as a treatment for the PE, and the patient underwent a biological aortic root replacement as part of a Bentall-procedure with a preformed 29 mm xenograft (Medtronic Freesytle®, Minneapolis, USA) one week later. The flap containing ascending aorta was resected, which appeared to be rather a localised chronic TAAD (Fig. 1D). than a supravalvular shelf lesion on a visual inspection and was replaced by an interposition tube graft.

Histopathology revealed nodular myxoid degenerative changes in the aortic valve, focal myxoid degeneration and fibrosis of intima and media, with focal cystic medial degeneration in the resected aortic wall segment. There was no evidence of hemorrhage in the vessel wall.

After a short recovery period, the patient was discharged on anticoagulation for the PE and with advice to undergo genetic testing for consideration of hereditary connective tissue disease; the latter was refused by the patient.

3. DISCUSSION

Aortic aneurysms are exceptionally uncommon in young adults and are often asymptomatic, and first discovered incidentally. Surgical solution for younger patients should be more radical than for the elderly TAAD population, to achieve reliable long-term outcomes. More extensive involvement of proximal and distal aorta, myocardial ischaemia and syndromic connective disorders characterise younger patients. Intimal tears localised in the aortic root are also more common at the lower age of presentation. Besides the well known syndromic connective tissue disorders and bicuspid aortic valve, non-syndromic familial thoracic aortic aneurysms are discovered in 20% of cases in diagnosed thoracic aneurysms and represent genetically heterogeneous disorders. Mutations in five genes (MYH11, TGFßR1, TGFßR2, MYLK and ACTA2) have been identified so far with all autosomal dominant inheritance in these cases. From a molecular point of view, consequences of genetic alterations translate into a degenerative remodelling of the aortic medial extracellular matrix resulting in progressive loss of elastic properties. Clinical, anatomical, genetic and molecular evidence suggests that the prevalence of inherited aortic wall disorders in young people presenting with aortic complications is probably higher than expected and diagnosed [6]. Therefore, genetic testing for hereditary aortopathies is essential in young patients having aortic aneurysms.

Fig. (1)

Chronic aortic dissection; pre- and intraoperative views.
A: Parasternal long axis echocardiographic view; arrow points on supravalvular flap.
B: Parasternal short axis echocardiographic view; arrow marks supravalvular flap.
C: Chest computed tomography at level of left main stem; arrow highlights the flap.
D: Intraoperative view of chronic aortic dissection; arrow shows the flap.


CONCLUSION

The patient had been treated with an intravenous heparin infusion for a DVT discovered incidentally on admission. In cases of a chronic TAAD, heparin does not pose any significant risks as strong connective tissue stabilises the aortic wall lesions. Nevertheless, in acute TAAD heparinisation may lead to fatal complications, including exsanguination from a covered aortic rupture or rapidly developing pericardial tamponade. Therefore, it is essential to distinguish between the symptoms and signs of the acute coronary syndrome and TAAD whenever possible.

LIST OF ABBREVIATIONS

DVT  =  Deep Venous Thrombosis
CT  =  Computed Tomography
PE  =  Pulmonary Embolism
TAAD  =  Type A Aortic Dissection

AUTHORS' CONTRIBUTIONS

• Laszlo Göbölös MD: manuscript writing, image extraction, image rendering, cardiosurgical patient care.

• Gurjyot Bajwa MD: manuscript and image review, cardiosurgical patient care.

• Jehad Ramahi MD: manuscript and image review, cardiosurgical patient care.

• Pier Carlo Bergonzi MD: manuscript and image review, cardiac intensive patient care.

• Gopal Bhatnagar MD: manuscript and image review, cardiosurgical patient care.

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

Not applicable.

HUMAN AND ANIMAL RIGHTS

Not applicable.

CONSENT FOR PUBLICATION

Not applicable.

STANDARD OF REPORTING

Care guidelines have been followed in this case report.

FUNDING

None.

CONFLICT OF INTEREST

The authors declare no conflict of interest, financial or otherwise.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Scott DJ, Campbell DN, Clarke DR, Goldberg SP, Karlin DR, Mitchell MB. Twenty-year surgical experience with congenital supravalvar aortic stenosis. Ann Thorac Surg 2009; 87(5): 1501-7.
[http://dx.doi.org/10.1016/j.athoracsur.2009.01.070] [PMID: 19379894]
[2] Bakhtiary F, Amer M, Etz CD, et al. Mid-term outcome after surgical repair of congenital supravalvular aortic stenosis by extended aortoplasty. Interact Cardiovasc Thorac Surg 2013; 17(4): 688-90.
[http://dx.doi.org/10.1093/icvts/ivt236] [PMID: 23793710]
[3] Isselbacher EM. Thoracic and abdominal aortic aneurysms. Circulation 2005; 111(6): 816-28.
[http://dx.doi.org/10.1161/01.CIR.0000154569.08857.7A] [PMID: 15710776]
[4] Bonser RS, Ranasinghe AM, Loubani M, et al. Evidence, lack of evidence, controversy and debate in the provision and performance of the surgery of acute type A aortic dissection. J Am Coll Cardiol 2011; 58(24): 2455-74.
[http://dx.doi.org/10.1016/j.jacc.2011.06.067] [PMID: 22133845]
[5] Peterss S, Hagl C, Pichlmaier M. Chronic aortic dissection type A: Simply an overlooked acute event? Eur J Cardiothorac Surg 2019; 57(2): 397-8.
[http://dx.doi.org/10.1093/ejcts/ezz218] [PMID: 31364697]
[6] Malvindi PG, Votano D, Ashoub A, et al. Age-related presentation of acute type A aortic dissection. Asian Cardiovasc Thorac Ann 2018; 26(9): 659-66.
[http://dx.doi.org/10.1177/0218492318810087] [PMID: 30379563]

Editor-in-Chief

Abdullah Shehab
Emirates Cardiac Society
Emirates Medical Association
Dubai
(UAE)

Biography View Full Editorial Board