1. Introduction

Aortic stenosis (AS) is a relatively frequent valvular heart disease that causes important hemodynamic problems, related to the obstruction of the blood outflow from the left ventricle. Bicuspid valves are a common finding in younger patients presenting with aortic stenosis. The condition seems congenital, with males affected predominantly, and with an overall prevalence of 1-2% ^[1]. Bicuspid aortic valve (BAV) is responsible for high frequency of aortic wall abnormalities, and aortic dilation seems to be so importantly present, to warrant corrective interventions. BAV patients with a high risk of aortic complications have been identified, among which those with aortic coarctation (corrected or not), with aortic stenosis, with severe valvular dysfunction or systemic hypertension, and individuals with positive familiar history for aortic dissection or rupture ^[2].

The impairment of cusp opening in the setting of AS will lead to a pressure overload, with a compensatory left ventricular hypertrophy (LVH), followed from a fall in the ventricular compliance ^[3]. Angina may result from the increased wall stress (especially in the setting of a hypertrophied myocardial tissue), and the situation might progress to heart failure if the systolic function of the left ventricle declines progressively. These occurrences are not the only one accompanying BAV complicated with valve stenosis; in fact the list is much longer, with coarctation of aorta, coronary arteries anomalies, aneurysm of sinus of Valsalva and of the ascending aorta, and other congenital heart defects ^[4].

Valve stenosis and its severity is an important parameter to be carefully evaluated and quantified. Gorlin formula calculated the valve area from the ratio of the cardiac output to the square root of the valve gradient; normal values suggested for the aortic valve arise from 2.5 to 3.5 cm², and the validity of this formula remains unaltered more than sixty years after the first application ^[5]. Echocardiography is an important and reliable diagnostic tool when professionally performed, since it allows the evaluation of the presence and of the severity of AS, and other concomitant anomalies ^[6]. Cardiac catheterization is feasible as well, but the valve might be impossible to cross when critically diseased, and the risk of embolic stroke following the procedure cannot be underemphasized ^[7].

2. Case Report

A Caucasian male aged 35 years old was referred to the Service of Cardiac Surgery, Tirana, following the advice of a previous cardiologist consultancy. The individual had an event described as syncope two days before presenting in our service, during a leisure time football match. The suspicion of an aortic stenosis was made after cardiac auscultation, and he underwent a thorough diagnostic procedure.

The findings of a trans-thoracic echocardiography were highly suggestive for BAV and of a severe AS with a gradient of 60 mmHg (sources define as severe stenosis all gradients surpassing 40 mmHg) ^[8]. The findings were further elaborated through trans-esophageal echocardiography, and summarized in the image below (Figure 1).

BAV existence was confirmed in the trans-esophageal echocardiography, and severe and progressive post-stenotic dilation of structures was observed (+ diameter = 2.86 cm [aortic ring]; X diameter = 4.29 cm [aortic bulb]; ۞ diameter = 4.88 cm [sinotubular junction]; § diameter = 6.11 cm [ascending aorta]). The over-mentioned and registered figures were abundantly above the normal values suggested from several sources ^{[9, 10, 11]}.

The co-existence of a clearly dilated ascending aorta, with a stenotic bicuspid valve, required further diagnostic clarification, and a computed tomography angiographic study was performed (angio-CT of the aorta). The CT study suggested a dilation of the ascending aorta with a diameter up to 7 centimeters; a massive reduction of the latter up to 1.8 centimeters followed immediately after the origin of the subclavian artery. The descending aorta reached a diameter of 4.5 centimeters, with a progressive decrease of this parameter, which equaled 2.7 centimeters close to the diaphragm (Figure 2 and Figure 3, respectively left insets).

This combination of a BAV, severe aortic stenosis, dilation of aorta, and coarctation of the latter immediately after the origin of the subclavian artery, warranted the immediate necessity for a surgical correction.

Figure 1. Trans-esophageal cardiac echocardiography (see text for explanations)

Download as

PowerPoint Slide

Larger image(png format)

Figures index

Veiw figure

View current figure in a new window

View next figure

Figure 2. Axial CT scan images: Pre-operative (Left insert) and Post-operative (Right insert). Note the considerable decrease in the diameter of ascending aorta from pre to post-operative images (white arrows). Pleural effusion as a post-operative sequela is seen in the left lung (white cross)

Download as

PowerPoint Slide

Larger image(png format)

Figures index

Veiw figure

View current figure in a new window

View previous figure

View next figure

Figure 3. CT scan reconstruction images of the aorta. Left insert: pre-operative situation, showing dilation of the ascending aorta and coarctation at the level of aortic isthmus. Right insert: post-operative reconstruction image, with a normalized ascending aorta and release of the constricted area at the level of coarctation

Download as

PowerPoint Slide

Larger image(png format)

Figures index

Veiw figure

View current figure in a new window

View previous figure

View next figure

The operation consisted in a median sternotomy, with replacement of the aortic valve with a mechanical prosthesis SJM no. 25 (St. Jude mechanical valve), a type of prosthesis considered widely reliable and with excellent long-term results ^[12]. These two important operative steps are shown in the Figure 4 (left and right inserts). The ascending aorta was replaced with an Albograft tube prosthesis no. 32 completed with suture line reinforcements as suggested from sources ^[13]. The aortic arch and the coarctation area were revised and 5-6 centimeters distally from the origin of the left subclavian artery was detected a membrane which narrowed the lumen of the aorta. The narrowing membrane was removed and a Dacron patch was inserted in situ covering the entire segment of the coarcted aorta, which hereby regained its normal diameter. Worth mentioning is that some authors recommend patches composed from other material; nevertheless all of those, including Dacron patches, have advantages and drawbacks of their own ^[14].

Figure 4. Intraoperative images; Left: median sternotomy; Right: aortic valve replacement

Download as

PowerPoint Slide

Larger image(png format)

Figures index

Veiw figure

View current figure in a new window

View previous figure

The surgical intervention ended up uneventfully; the patient was discharged home eleven days after the operation, with oral anticoagulants (Warfarin) in the maintenance therapy. Monthly clinical and echography follow-ups have shown a stable improvement of the general condition, and cardiac function parameters within normality.

3. Discussion

We dealt with a case of syncope in a previously young adult, an episode that was clearly stress-provoked (during a football game). The differential diagnosis of syncope is extremely detailed and out of the scope of the present paper; however, the clinical and radiological images of a combined BAV, AS, post-stenotic dilation of aorta, and coarctation were highly suggestive of a serious medical condition. Such a combination (BAV, AS, dilation of aorta and coarctation) is reported in the casuistics, and mutual influences in between the valve morphological characteristics with the presence, severity and outcome of aortic dilation or coarctation have been scrutinized ^{[15, 16]}.

Asymptomatic AS is not a rare condition; from the moment AS becomes symptomatic, authors suggest an average survival of less than 2-3 years. Indications for surgery are angina, CHF and syncope, but treating clinicians should take into account the clear influence and correlation between AS and the risk of sudden cardiac death ^[17]. Another controversy when detecting occasionally an asymptomatic AS is related with the unclear character of the progression of the disorder ^[18]. Worries regarding sports activity in patients with BAV and the potential of the latter for unleashing potentially fatal cardiac disorders have been formulated ^[19].

In all cases, a careful monitoring is warranted, particularly in patients with previous fainting episodes, with a positive family history for aortic diseases, or in particular physiological situations such as pregnancy ^[20]. In a recent publication of our centre’s data, we compared the results of aortic surgery between two subgroups of patients, the second of which had a simultaneous coronary artery bypass graft; meanwhile the first subgroup had aortic valve surgery alone, concluding that a combined surgical intervention did not affect the long-term results of either from the procedures ^[21]. When it comes to surgical approaches, there is however a consistent trend of specialized facilities in reporting better results, with increasingly lower morbidity and mortality, even for interventions of a major importance, such as the aortic surgery. This optimistic overview has led to conceptual changes as well: fast-track elective open aortic surgery, with minimally invasive surgery and anesthesia, early oral feeding and ambulation, is advocated as another valid option, with similar good results ^[22].

Abbreviations

AS (aortic stenosis); LVH (left ventricular hypertrophy); BAV (bicuspid aortic valve); CHF (cardiac heart failure).

References

[1]	Yuan SM, Jing H, Lavee J. The bicuspid aortic valve and its relation to aortic dilation. Clinics (Sao Paulo). 2010 May; 65 (5): 497-505.
	In article		CrossRef PubMed
[2]	Evangelista A. Bicuspid aortic valve and aortic root disease. Curr Cardiol Rep. 2011 Jun; 13 (3): 234-41.
	In article		CrossRef PubMed
[3]	Carabello BA, Crawford FA Jr. Valvular heart disease. N Engl J Med 1997; 337: 32-41.
	In article		CrossRef PubMed
[4]	Braverman AC. Aortic involvement in patients with a bicuspid aortic valve. Heart. 2011 Mar; 97 (6): 506-13.
	In article		CrossRef PubMed
[5]	Gorlin R, Gorlin SG. Hydraulic formula for calculation of the area of the stenotic mitral valve, other cardiac valves, and central circulatory shunts. I. Am Heart J. 1951 Jan; 41 (1): 1-29.
	In article		CrossRef
[6]	Mochizuki Y, Pandian NG. Role of echocardiography in the diagnosis and treatment of patients with aortic stenosis. Curr Opin Cardiol 2003; 18: 327-33.
	In article		CrossRef
[7]	Omran H, Schmidt H, Hackenbroch M, et al. Silent and apparent cerebral embolism after retrograde catheterization of the aortic valve in valvular stenosis: a prospective, randomized study. Lancet 2003; 361: 1241-6.
	In article		CrossRef
[8]	Oppizzi M. Echocardiography in the perioperative decision making of patients with aortic stenosis. HSR Proc Intensive Care Cardiovasc Anesth. 2009; 1 (1): 7-15.
	In article
[9]	Erbel R, Eggebrecht H. Aortic dimensions and the risk of dissection. Heart. 2006 Jan; 92 (1): 137-42.
	In article		CrossRef PubMed
[10]	De Kerchove L, El Khoury G. Anatomy and pathophysiology of the ventriculo-aortic junction: implication in aortic valve repair surgery. Ann Cardiothorac Surg. 2013 Jan; 2 (1): 57-64.
	In article		PubMed
[11]	Kaine SF, Smith EO, Mott AR, Mullins CE, Geva T. Quantitative echocardiographic analysis of the aortic arch predicts outcome of balloon angioplasty of native coarctation of the aorta. Circulation. 1996 Sep 1; 94 (5): 1056-62.
	In article		CrossRef PubMed
[12]	Toole JM, Stroud MR, Kratz JM, Crumbley AJ 3rd, Bradley SM, Crawford FA Jr, Ikonomidis JS. Twenty-five year experience with the St. Jude medical mechanical valve prosthesis. Ann Thorac Surg. 2010 May; 89 (5): 1402-9.
	In article		CrossRef PubMed
[13]	Mitrev Z, Belostotskii V, Hristov N. Suture line reinforcement using suction-assisted bioglue application during surgery for acute aortic dissection. Interact Cardiovasc Thorac Surg. 2007 Apr; 6 (2): 147-9. Epub 2006 Dec 18.
	In article		CrossRef PubMed
[14]	Backer CL, Paape K, Zales VR, Weigel TJ, Mavroudis C. Coarctation of the aorta. Repair with polytetrafluoroethylene patch aortoplasty. Circulation. 1995 Nov 1; 92 (9 Suppl): II132-6.
	In article		CrossRef PubMed
[15]	Beaton AZ, Nguyen T, Lai WW, Chatterjee S, Ramaswamy P, Lytrivi ID, Parness IA, Srivastava S. Relation of coarctation of the aorta to the occurrence of ascending aortic dilation in children and young adults with bicuspid aortic valves. Am J Cardiol. 2009 Jan 15; 103 (2): 266-70.
	In article		CrossRef PubMed
[16]	Clair M, Fernandes SM, Khairy P, Graham DA, Krieger EV, Opotowsky AR, Singh MN, Colan SD, Meijboom EJ, Landzberg MJ. Aortic valve dysfunction and aortic dilation in adults with coarctation of the aorta. Congenit Heart Dis. 2014 May-Jun; 9 (3): 235-43.
	In article		CrossRef PubMed
[17]	Pellika PA, Nishimura RA, Bailey KR, Tajik AJ. The natural history of adults with asymptomatic, hemodynamically significant aortic stenosis. J Am Coll Cardiol 1990; 15: 1012-7.
	In article		CrossRef
[18]	Otto CM, Burwash IG, Legget ME, et al. Prospective study of asymptomatic valvular aortic stenosis. Clinical, echocardiographic, and exercise predictors of outcome. Circulation 1997; 95: 2262-70.
	In article		CrossRef PubMed
[19]	Zeppilli P, Bianco M, Bria S, Palmieri V. Bicuspid aortic valve: an innocent finding or a potentially life-threatening anomaly whose complications may be elicited by sports activity? J Cardiovasc Med (Hagerstown). 2006 Apr; 7 (4): 282-7.
	In article		CrossRef PubMed
[20]	Bara P, Gjyli L, Gega M, Belshi Xh, Vyshka G. Aortic pathologies and pregnancy: a special focus on connective tissue disorders. Cardiology and Angiology: An International Journal. 2014; 2 (3): 147-153.
	In article		CrossRef
[21]	Dumani S, Petrela E, Likaj E, Harja E, Vyshka G, Refatllari A. Early and long term outcomes of aortic valve surgery combined or not with CABG surgery. International Journal of Clinical Therapeutics and Diagnosis. 2014; 2 (1): 1-9.
	In article
[22]	Brustia P, Peinetti F. Fast track aortic surgery: why not? Advances in Life Sciences and Health. 2014; 1 (1): 9-18.
	In article