Ann Thorac Surg 2002;73:973-975
© 2002 The Society of Thoracic Surgeons
Case report
Three-decade follow-up in pulmonary artery ectasia: risk assessment strategy
Christof Rose, MD*a,
Armin Wessel, MDa
a Clinic for Pediatric Cardiology, University of Göttingen, Göttingen, Germany
Accepted for publication June 22, 2001.
* Address reprint requests to Dr Rose, Klinik für Pädiatrische Kardiologie, Universität Göttingen, Robert-Koch-Str 40, 37075 Göttingen, Germany
e-mail: crose{at}gwdg.de
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Abstract
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We present a 29-year follow-up in a patient with ectasia of the pulmonary trunk and mild valvular stenosis. There was no progression from the first presentation at the age of 15 months until the actual age of 30 years, the z-value of the diameter of the pulmonary trunk remaining almost constant (z-value 22). This indicates that pulmonary dilatation with normal pressure may be a benign disease.
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Introduction
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The real incidence of aneurysm of the pulmonary artery is unclear, because most cases remain asymptomatic and probably never become symptomatic. In a large autopsy review in 1947, Deterling and Clagett confirmed a low incidence of aneurysms in about 1:13,700 cases [1]. Since infectious causes are no more important causes for vasculitis, one half of the cases are associated with congenital heart disease. Left-to-right shunts with increased pulmonary blood flow or pulmonary hypertension especially lead to vessel dilatation. Pulmonary ectasia is also known in Marfan’s syndrome and severe valvular stenosis [2]. Idiopathic dilatation of the pulmonary artery is defined as a simple dilatation of the pulmonary trunk without involvement of the arterial tree in absence of intra- or extrapulmonary shunts, arterial wall disease, chronic pulmonary or cardiac disease, and normal pressure in the right ventricle and pulmonary artery [3].
We report the case of a patient with mild pulmonary valve stenosis and dilatation of the pulmonary artery, and his follow-up over 30 years. The patient was first seen in our institution at the age of 15 months for evaluation of a heart murmur. At clinical examination, a pulmonary valve stenosis was suspected. Cardiac catheterization was performed at the age of 3 years and confirmed the diagnosis of a mild pulmonary stenosis with a systolic peak-to-peak gradient of 32 mm Hg. Pressures in the pulmonary artery were normal; no angiograms were performed at this time. The patient was followed in a 2-year schedule with no significant change in clinics, chest roentgenogram (Fig 1A),
or electrocardiogram. Ultrasound was first performed in 1988 showing a huge aneurysmatic dilatation of the pulmonary trunk and branches. Recatheterization was performed in February 1992. There was no change in pulmonary valve gradient and pulmonary artery pressure. An angiogram of the pulmonary artery confirmed pulmonary ectasia of the trunk and branches (Fig 2).
At the time of his last presentation in November 2000, physical examination was still unchanged. Doppler echocardiography and chest roentgenogram did not show progression of the pulmonary artery dilatation (Fig 1B). Magnetic resonance angiography was able to demonstrate the pulmonary artery dilatation (Fig 3).
Table 1
compares the morphometric measurements of chest roentgenograms, angiograms, and magnetic resonance angiograms. The data suggest that there was no progressive dilatation of the pulmonary arteries over 30 years.
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Fig 1. Chest roentgenogram at the age of (A) 15 months and (B) 30 years. There are no significant changes in shape of the heart shadow.
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Fig 2. Conventional angiography at the age of 21 years. Dilatation of the pulmonary trunk to maximum diameter of 57 mm.
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Fig 3. Magnetic resonance angiography in maximum intensity projection in a left anterior oblique projection at the age of 30 years. This view shows the dilated pulmonary trunk and the branches.
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Comment
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Pulmonary valve stenosis can lead to some degree of poststenotic dilatation, but it is very uncommon in mild or trivial stenosis [5, 6]. Therefore, a congenital weakness of the arterial wall must be considered a concomitant lesion [3]. Clinical symptoms may consist of chronic cough and dyspnea when airway obstruction is present [6]. Generally, patients are asymptomatic and a prominent pulmonary segment is coincidentally diagnosed on a chest roentgenogram. The need of surgical treatment is discussed controversially in literature. Some authors are afraid of sudden death by pulmonary artery rupture which they feel is confirmed by some autopsy studies [2, 6]. But to our knowledge, no case of rupture of a trunk aneurysm with normal pulmonary pressure has been described. Most patients with ruptured aneurysms of the pulmonary trunk had a history of pulmonary hypertension [7]. For aortic root dilatation in Marfan’s disease, a diameter of 5 to 6 cm is considered a high risk for rupture, and aortic root replacement is recommended [8].
Thus, we derived a diagram for risk assessment in patients with pulmonary trunk aneurysm. As the normal aortic wall stress amounts to about 850 kdyn/cm2, we considered a wall stress of about 1,900 kdyn/cm2 as an indication for surgical intervention. This value can be derived from the aortic wall in patients with Marfan’s disease at a diameter of 5.5 cm and systolic pressure of 100 mm Hg. According to the LaPlace equation [WS = 1.35xPxr/h] (Fig 4) we calculated the interrelationship between diameter of the vessel and wall stress (WS) for various aortic and pulmonary pressures (P). We assumed the aortic wall thickness to be h = 0.2 cm and the pulmonary wall thickness to be h = 0.1 cm, respectively. In Figure 4, the curves are depicted and it becomes obvious, on the one hand, that the critical wall stress of 1,900 dyn/cm2 occurs if the diameter of the pulmonary artery exceeds 10 cm at normal systolic pressures up to 25 mm Hg. On the other hand, one has to be aware that in pulmonary hypertension, wall stress increases rapidly. These interrelations explain why, in pulmonary hypertension, rupture of the pulmonary trunk may occur in the face of slight dilatation [7].
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Fig 4. Interrelationship of wall stress (WS) and vessel diameter at different pressure levels in aorta (Ao) and pulmonary artery (PA). (WS = 1.35*P*[D/2]/h [h: Ao = 0.2 cm; Pa = 0.1 cm].) At 55 mm, wall stress in the aorta reaches the critical level of 1,900 kdyn/cm2 (arrow), whereas wall stress in our patients at the age of 21 years is far below (solid circle). Pressure levels: (1) 80 mm Hg for PAP or 160 mm Hg for AoP; (2) 50 mm Hg for PAP or 100 mm Hg for AoP; and (3) 20 mm Hg for PAP. (AoP = aortic pressure; D = vessel diameter; h = wall thickness; PAP = pulmonary artery pressure.)
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The individual data for our patient at 21 years demonstrate that the assumed wall stress is far below the critical value. Thus, there is no evidence for the necessity of surgical intervention to prevent rupture at the present time. Special regard has to be given to progressive dilatation and a closed follow-up in a 2-year schedule has to be recommended. Magnetic resonance angiography seems to be the ideal diagnostic tool for follow-up.
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References
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Deterling R.A., Jr, Clagett O.T. Aneurysm of the pulmonary artery: review of literature and report of a case. Am Heart J 1947;34:471-498.
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Bartter T., Irwin R.S., Nash G. Aneurysms of the pulmonary arteries. Chest 1988;94:1065-1075.[Free Full Text]
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Ugolini P., Mousseaux E., Sadou Y., et al. Idiopathic dilatation of the pulmonary artery: report of four cases. Magn Reson Imaging 1999;17:933-937.[Medline]
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Rammos S., Kramer H.H., Trampisch H.J., Krogmann O.N., Kozlik R., Bourgeois M. Normalwerte des Wachstums der Pulmonalarterien im Kindesalter. Eine angiographische Studie. Herz 1989;14:348-357.[Medline]
-
Mohan J.C., Jain P., Arora R. Aneurysm of the pulmonary trunk in association with minimal pulmonary stenosis. Int J Cardiol 1989;23:253-255.[Medline]
-
Chen Y.F., Chaw-Chi C., Lee C.S. Giant aneurysm of main pulmonary artery. Ann Thorac Surg 1996;62:272-274.[Abstract/Free Full Text]
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Butto F., Lucas R.V., Edwards J.E. Pulmonary arterial aneurysm. A pathologic study of five cases. Chest 1987;91:237-241.[Abstract/Free Full Text]
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Gott V.L., Greene P.S., Alejo D.E., et al. Replacement of the aortic root in patients with Marfan’s syndrome. N Engl J Med 1999;340:1307-1313.[Abstract/Free Full Text]
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Abstract
Introduction
