Aneurysm of sinus of Valsalva

Increasingly frequent reports of unruptured aneurysms in recent years is due to easy availability of echocardiography.[1] Isolated unruptured aneurysms of the sinus of Valsalva present with aortic regurgitation,[2] right ventricular outflow obstruction causing congestive heart failure,[3] complete heart block,[4] coronary artery compression,[5] resistant ventricular tachycardia,[6] and left/right ventricular inflow obstruction.[7] In all the reported cases of patients with right ventricular outflow tract obstruction, the aneurysm arose from the right coronary sinus[3] and was caused by its close proximity to the right ventricular outflow tract. An isolated unruptrued aneurysm of the left coronary sinus of Valsalva is rare.[7,8] Of the five reported cases, three patients had left coronary artery compression,[5] one had left atrioventricular valve obstruction,[7] and one remained asymptomatic for 19 years without surgery.[9] To our knowledge, a left sinus of Valsalva aneurysm presenting as right ventricular outflow tract obstruction has not been reported in the literature so far. Moreover, acute presentation as seen in our patient is extremely unusual.[3,5]

Case Report

A 30-year-old man presented with exertional dyspnea of two weeks' duration with acute worsening of symptoms 48 h prior to the hospital admission. Physical examination revealed the patient to be orthopneic with blood pressure of 106/74 mm Hg, pulse of 110 beats per minute, and respiratory rate of 36 per minute. The jugular venous pressure was elevated up to the angle of the mandible, with prominent "a" and "v" waves. Cardiovascular examination revealed evidence of mild cardiomegaly, prominent right ventricular heave, systolic thrill in the left third intercostal space, soft pulmonic component, and right ventricular [S.sub.3] gallop. A grade 4/6 ejection systolic murmur was heard in the pulmonary area and a grade 2/6 pansystolic murmur was heard in the tricuspid area. The liver was tender and palpable 10 cm below the right costal margin.

The ECG revealed sinus rhythm, QRS axis of + 120 [Degrees] in frontal plane, peaked P-wave, PR interval of 140 ms, rSr in [V.sub.1] and T-wave inversion in [V.sub.1-V.sub.4].

The chest roetgenogram revealed a cardiothoracic ratio of 55 percent with normal lung vascularity. There was a convex bulge along the left cardiac border below the pulmonary trunk segment at the level of the left atrial appendage.

The two-dimensional echocardiogram showed a large aneurysm arising from the left coronary sinus and bulging into the right ventricular outflow tract. The right ventricle was dilated and there was a systolic flutter on the pulmonary valve. Doppler study showed a peak systolic gradient of 64 mm Hg across the right ventricular outflow tract and grade 2 aortic regurgitation.

Cardiac catheterization revealed a peak systolic gradient of 70 mm Hg between the right ventricular body and the outflow. The right ventricular end-diastolic pressure was 12 mm Hg. Left-sided pressures were normal, and oxygen saturation study showed no intracardiac shunting. Aortic root angiogram done in the right anterior oblique projection showed a large smooth-walled left sinus of Valsalva aneurysm (Fig 1, a) bulging anterosuperiorly and to the left, with grade 3 aortic regurgitation. Right ventricular angiogram done in the same view showed a markedly narrowed outflow tract and a dilated, poorly contracting ventricle with severe tricuspid regurgitation. The aortic sinus aneurysm was seen as a negative shadow encroaching into the right ventricular outflow tract (Fig 1, b).

The patient underwent surgery using total cardiopulmonary bypass. The saccular aneurysm was seen to arise from the central and right part of the left coronary sinus of Valsalva just inferior to the left coronary ostium (Fig 2) and burrowed posterior and lateral to the aortic root. The aneurysmal sac had two separate outpouchings, the posterior one protruded into the free pericardial space below the left coronary artery and ended blindly. The anterior part of the aneurysm had burrowed between the aortic annulus and the pulmonary trunk to extend below the pulmonary annulus into the right ventricular outflow tract. The right ventricular outflow tract below the pulmonary annulus was opened by a vertical incision to visualize the aneurysm. The aortic end of the aneurysm was repaired with a Dacron patch and the right ventricular end was resected and plicated. The aortic valve was replaced by 22-mm Starr-Edwards mechanical prostheses. The postoperative course was uneventful. Histopathologic examination of the resected aneurysm showed subendocardial fibrosis with no evidence of inflammation or mucoid degeneration.

Discussion

As in the case of berry aneurysms of the intracranial circulation, the basic defect in patients with congenital aneurysms of aortic sinuses is deficiency of aortic media behind the sinus.[8] The high aortic pressure in the presence of the defective media[8] results in aneurysm formation, usually in the second or third decade as seen in our patient.[2,7] The acute development of right-sided heart failure in the absence of rupture prompts us to speculate that the size of the aneurysm[3,5] may have suddenly increased leading to acute right ventricular outflow tract obstruction. Whether this sudden increase in size is part of the natural history of congenital aneurysms of the sinus of Valsalva just before rupture, similar to one described in cases of intracranial berry aneurysms of the circle of Willis,[10] remains to be confirmed.

The normal left aortic sinus can be divided into three parts.[8] The posterior part is adjacent to the left atrial wall, the right part is related to the wall of the pulmonary trunk at the level of the left pulmonary sinus, and the central part is directly related to the epicardium.[8] The unusual surgical anatomy and extent of the aneurysm in the present patient was not amenable to simple closure of the mouth of the aneurysm from the aortic end, but required an aortocameral approach, as is performed for aneurysms that rupture into a cardiac chamber.[11]

References

[1] Lewis BS, Agathangelow NE. Echocardiographic diagnosis of an unruptured sinus of Valsalva aneurysm. Am Heart J 1984; 107:1025-27 [2] Boutefeu JM, Moret PR, Hahn C, Hauf EH. Aneurysms of the sinus of Valsalva: report of seven cases and review of literature. Am J Med 1978; 65:18-24 [3] Haraphongse M, Ayudhya RK, Jugdutt B, Rossall RE. Isolated unruptured sinus of Valsalva aneurysm producing right ventriculcar outflow obstruction. Cathet Cardiovasc Diagn 1990; 19:98-102 [4] Lokhandwala YY, Khanolkar UB, Rajani R, Sathe S, Kaneria V, Srinivas A, et al. Unruptured aneurysm of the sinus of Valsalva: report of two cases. India Heart J 1989; 41:68-71 [5] Hiyamuta K, Ohtsuki T, Shimamatsu M, Onkita Y, Tarasawa M, Bekki H, et al. Aneurysm of the left sinus causing acute myocardial infarction. Circulation 1993; 67:1151-54 [6] Raizes GS, Smith HC, Vlietstra RE, Puga FJ. Ventricular tachycardia secondary to aneurysm of sinus of Valsalva. J Thorac Cardiovasc Surg 1979; 78:110-15 [7] Taguchi K, Sasaki N, Matsuura Y, Uemura R. Surgical correction of aneurysm of the sinus of Valsalva: a report of 45 consecutive patients including eight with total replacement of the aortic valve. Am J Cardiol 1969; 23:180-91 [8] Edwards JE, Burchell HB. The pathological anatomy of deficiencies between the aortic root and the heart, including aortic sinus aneurysms. Thorac 1957; 12:125-39 [9] Martin LW, Hsu I, Schwartz H, Wasserman AG. Congenital aneurysm of the left sinus of Valsalva: report of a patient with 19 year survival without surgery. Chest 1986; 90:143-45 [10] Wiebers DO, Whisnant JP, O'Fallon WM. The natural history of unruptured intracranial aneurysms. N Engl J Med 1981; 304:696-98 [11] Chu SH, Hung CR, How SS, Chang H, Wang SS, Tsai Ch, et al. Ruptured aneurysms of the sinus of Valsalva in Oriental patients. J Thorac Cardiovasc Surg 1980; 99:288-98

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