Spontaneous rupture of bicuspid aortic valve. An unusual cause of aortic insufficiency

Acute severe aortic insufficiency during cardiopulmonary bypass in a bicuspid aortic valve with unrecognized annular displacement and fibrous strands: a case report

Background

Bicuspid aortic valve (BAV) with displacement of the attachment of the conjoined aortic leaflet and fibrous strands is a rare cardiac malformation. We report a case of BAV that presented as acute massive aortic regurgitation during cardiopulmonary bypass for a planned non-valve-related procedure and was successfully treated by emergency aortic valve replacement.

Case summary

A 70-year-old man with triple vessel coronary disease and severe left ventricular systolic dysfunction underwent coronary bypass grafting and graft replacement of the ascending aorta. Acute aortic regurgitation occurred during ventricular fibrillation and after de-clamping of the aortic graft. Intra-operative findings included a fused BAV (right-left cusp fusion), very asymmetrical leaflet (commissure angle of the non-fused leaflet 135°), three aortic sinuses, and conjoined leaflets originating from the myocardium in the inter-ventricular septum. The aortic leaflets were resected and replaced with a prosthetic aortic valve at the attachment site of the conjoined leaflets. Post-operatively, no peri-valvular leaks were observed, and left ventricular function was improved.

Discussion

Intra-operative acute massive aortic regurgitation may be caused by a morphologically abnormal aortic leaflet and root complex in patients with a BAV. The dilated aortic root, asymmetrical leaflet, and abnormal aortic leaflet insertion, with thick septal myocardium of the coronary aortic sinus, might have caused unstable leaflet co-aptation, leading to deformation of the aortic leaflets influenced by the change in myocardial tone and intra-operative change in the sinotubular junction. Familiarity with the classification of congenital BAV, and the anatomy of the normal and abnormal aortic root complex, is important.

Aortic valve fenestrations: a review

BACKGROUND

Aortic valve fenestrations (AVFs) seem to be relatively common; however, their impact in human heart disease is not entirely clear.

METHODS

A review was carried out to assess all scientific literature on human patients related to AVFs, as described in the published literature. The search was conducted on 2 different databases, Medline (PubMed), and ISI Web of Knowledge.

RESULTS

Fifty-five reports were under analysis. Autopsy studies showed AVFs to be present in 55.9% of individuals studied in such studies. They occur more frequently in men and, in general, their frequency increases with age. Although common, fenestrations rarely cause regurgitation; however, they may play an important role in the pathophysiology of some cases of severe aortic regurgitation. AVFs have been described in patients with Down syndrome and Marfan syndrome, in patients with bicuspid or quadricuspid valves, and in patients with myxomatous valvular degeneration. Echocardiographic assessment of aortic regurgitation seems to have limitations in the diagnosis of valvular fenestrations.

CONCLUSIONS

Fenestrations of the aortic valve are very common and are associated with certain clinical conditions. It is unknown if AVFs play any role in the current epidemic of aortic valve disease. Future studies should aim to better define the role of AVFs in aortic valve disease, to further understand its etiology and to develop diagnostic criteria.

Aortic regurgitation caused by rupture of the abnormal fibrous band between the aortic valve and aortic wall

This report documents the sudden onset of aortic regurgitation (AR) by an exceptional cause. A 68-year-old woman suddenly experienced general fatigue, and AR was diagnosed. One year later, we performed aortic valve replacement. At surgery, three aortic cusps with a larger noncoronary cusp had prolapsed along with a free-floating fibrous band that had previously anchored the cusp to the aortic wall. Its rupture had induced the sudden onset of AR. There was no sign of infectious endocarditis. We performed successful aortic valve replacement.

A fibrous band associated with the non-coronary aortic valve cusp in a dog

A fibrous band connecting the middle of the free edge (nodulus Arantii) of the non-coronary aortic valve cusp to the ascending aorta just above the level of the non-coronary sinus of Valsalva was observed in an asymptomatic, 11-year-old, male Border Collie. The fibrous band was unrelated to the cause of the death in this dog. Such fibrous bands are usually reported in humans with congenital bicuspid aortic valves. To our knowledge, this is the first report of a fibrous band in the aortic valve in a domestic animal.

Sudden deterioration of aortic regurgitation due to rupture of a raphal cord on the conjoined cusp

A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.

The aortic valve with two leaflets--a study in 2,000 autopsies

Our study is based on the examination of 2,000 aortic valves obtained from fresh cadavers (1,499 males, 501 females) at the Institute of Forensic Medicine in Rio de Janeiro. We discovered 13 valves having two leaflets, giving a prevalence of 0.65%, much lower than generally reported in the literature. All 13 valves were from males, 10 from whites, three from mulattos, and none from blacks. Special attention was given to the raphe and the leaflets, the calcification of which can lead to stenosis. The only valves with normal texture and flexibility were two obtained from children less than one year old. All the other valves were thickened, and five of them had some degree of calcification. Six valves were judged to be functioning normally, while 7 valves were abnormal, 5 being stenotic and two showing evidence of insufficiency. The insufficiency in one was due to endocarditis, but in the other was due to redundancy of the leaflets. The only other cardiac anomaly discovered in these 13 cases was one patient with aortic coarctation. Bifoliate aortic valve, therefore, is probably the most common cardiac anomaly, although its prevalence as discovered in Brazil is lower than that reported in the literature. It affects mainly white males. After the fourth decade of life, most valves present some thickening, with stenosis being the most common complication. As is well recognised, infective endocarditis and aortic insufficiency are the other frequent complications. It is in general, nonetheless, an isolated anomaly.

Acute aortic regurgitation due to spontaneous rupture of a fenestrated cusp: report in a 65-year-old man and review of seven additional cases

A 65-year-old man with chronic hypertension developed dyspnea, a cough, and a new diastolic murmur. Two-dimensional echocardiography showed severe aortic regurgitation. No valvular vegetations were identified and blood cultures were negative. Surgical intervention was recommended, but the patient died of an acute intracranial hemorrhage two weeks later. At autopsy, the posterior aortic cusp was flail, due to rupture of the residual cord above two large fenestrations. There was no acute or healed endocarditis. To our knowledge, this is the eighth reported case of aortic valve incompetence due to spontaneous rupture of a fenestrated cusp. Patients ranged in age from 31-67 years (mean, 54), and 4 (50%) were older than 60 years. Seven (88%) of the 8 were men, and 4 (57%) of 7 had chronic hypertension. Analogously, in another four reported cases, aortic insufficiency developed following spontaneous rupture of the fenestrated raphe of an atypical congenitally bicuspid aortic valve. Noninfective and nontraumatic rupture of cord-like aortic valve structures may result in severe acute aortic regurgitation, particularly in men with chronic hypertension.

Congenitally bicuspid aortic valves: a surgical pathology study of 542 cases (1991 through 1996) and a literature review of 2,715 additional cases

OBJECTIVE

To describe a clinicopathologic study of a large group of congenitally bicuspid aortic valves surgically excised at a single institution.

MATERIAL AND METHODS

The medical charts and bicuspid valves from patients undergoing aortic valve replacement at Mayo Clinic Rochester between 1991 and 1996 were retrospectively reviewed.

RESULTS

The age of the 542 patients ranged from 1 to 86 years (mean, 61), and 372 (69%) were men. Among these, 409 (75%) had pure aortic stenosis (AS), 73 (13%) had pure aortic insufficiency (regurgitation) (AI), 53 (10%) had combined AS and AI, and 7 (1%) had normal function. The mean age was higher for those with AS than AI (65 versus 46 years; P < 0.001), whereas the male-to-female ratio was higher for AI than AS (17.3:1 versus 1.7:1; P < 0.001). The two cusps were not equal in size in 95%, and a raphe was present in 76% (67% typical, 9% atypical). Raphal position was described in 315 and was between the right and left cusps in 270 (86%). Raphal absence occurred more often in valves with equal-sized cusps than unequal (33% versus 14%; P = 0.005). Moderate to severe calcification affected valves with AS more frequently than AI (99% versus 41%; P < 0.001). In contrast, annular dilatation was associated with AI more than AS (48% versus 11%; P < 0.001). Acquired commissural fusion involved valves with combined AS and AI more often than the other functional states (31% versus 14%; P = 0.002). Sixteen patients (age range, 18 to 78 years; 13 men) had infective endocarditis (6 active, 10 healed), including 10 with AI (9 men), 3 with AS plus AI, 2 with AS, and 1 with normal function but embolization.

CONCLUSION

Functionally, the most common fate of congenitally bicuspid aortic valves was calcific stenosis with or without regurgitation (85%). Because approximately 4 million US citizens have bicuspid valves and because valve replacement is currently the only treatment of symptomatic AS, this disorder will continue to affect health-care costs.

Acute aortic regurgitation due to spontaneous rupture of a bicuspid aortic valve: detection by echocardiography

A 42-year-old man was admitted with acute severe aortic regurgitation. There were no signs of a systemic infection. M-mode and two-dimensional echocardiography revealed bicuspid aortic valve and echocardiographic features consistent with aortic leaflet rupture. The diagnosis was confirmed at surgery. This report illustrates that spontaneous rupture of a bicuspid aortic valve should be considered in acute aortic regurgitation without infective endocarditis.