Ann Thorac Surg 2006;82:2270-2272
© 2006 The Society of Thoracic Surgeons
Case Reports
Pulmonary Artery Aneurysm With Ascending Aortic Aneurysm Concomitant With Bilateral Bicuspid Semilunar Valves
Koichi Sughimoto, MD*,
Kiyoharu Nakano, MD,
Akihiko Gomi, MD,
Hayao Nakatani, MD,
Yoshitsugu Nakamura, MD,
Atsuhiko Sato, MD
NTT Kanto MC, Shinagawa-ward, Tokyo, Japan
Accepted for publication April 27, 2006.
* Address correspondence to Dr Sughimoto, NTT Kanto MC, 5-9-22 Higashi-Gotanda, Shinagawa-ward, Tokyo, 141-8625 Japan. (Email: cedarh7dion{at}yahoo.co.jp).
 |
Abstract
|
|---|
Aneurysm of both the pulmonary trunk and the ascending aorta concomitant with bilateral bicuspid valves is very rare. The reason for the formation of aneurysm with bicuspid semilunar valve is still inconclusive. Surgical repair was performed successfully (ie, aortic valve replacement, graft replacement for the ascending aorta, and plication of the pulmonary artery). Pathology of the pulmonary artery wall did not demonstrate cystic medial necrosis. The hemodynamic turbulence by the bilateral bicuspid valve may cause the formation of aneurysms even at low pressure. This case demonstrates an explanation for aneurysm with the bicuspid valve.
|
Introduction
|
|---|
The bicuspid semilunar valve is known to cause poststenotic dilatation. The mechanism of the poststenotic dilatation is still poorly understood. Surgical treatment was successfully done for the pulmonary artery and ascending aortic aneurysms, concomitant with bilateral bicuspid semilunar valves. This case may yield an explanation for the formation of poststenotic dilatation.
A 63-year-old woman was referred to our hospital for a cardiac operation. She had been diagnosed with valvular disease at the age of 30, and at that time, aortic valve stenosis and regurgitation was found by ultrasound cardiography. At regular follow-up, a recent computed tomographic scan showed dilatation of both the ascending aorta and pulmonary trunk, and a ultrasound cardiography showed a gradual rise in the pressure gradient of the aortic valve. Thus cardiac operation was imminent. She had already had a mastectomy for breast cancer of the right breast and had undergone radiation therapy 4 months before the cardiac operation. On auscultation, systolic murmur of Levine III/VI was heard on the second right sternal border. A chest roentgenogram showed no congestion and chest thoracic ratio was 66%. An electrocardiogram showed normal sinus rhythm, left axis deviation, and the strain pattern of ST segment in leads V5 and V6. A ultrasound cardiography showed left ventricular (LV) hypertrophy and LV dilatation (LV diastolic diameter, 58 mm; LV systolic diameter, 41 mm). The peak velocity of the aortic valve was 5.3 m/sec, which indicated 112 mm Hg on the pressure gradient. Aortic regurgitation was mild and the aortic valve was bicuspid on the short-axis view. The pulmonary valve had mild regurgitation. A computed tomographic scan also revealed that the ascending aorta dilatation was 57 mm and the pulmonary trunk dilatation was 56 mm. Catheterization data showed no raised pulmonary hypertension (main pulmonary artery pressure, 22 mm Hg) and no apparent pressure gradient on the pulmonary valve. A coronary angiogram showed normal coronary arteries.
At the time of operation, a cardiopulmonary bypass was established with the left femoral artery and bi-caval cannulation. In the gross anatomy, both the dilatated trunk (ie, the ascending aorta and main pulmonary artery) were occupying the pericardial cavity (Fig 1). The aortic valve was a bicuspid valve; the left coronary cusp and noncoronary cusp were fused with raphe. Dense calcification was observed on the aortic valve, which extended into the LV wall. The aortic valve was excised and replaced with a bioprosthetic valve (Carpentier-Edwards PERIMOUNT aortic heart valve [Edwards Lifesciences, Irvine, CA], 25 mm). The dilated ascending aorta was excised and replaced with an artificial graft (InterGard, 28 mm, InterVascular, La Ciotat, France). Second, the main pulmonary artery was incised longitudinally and was well inspected. The pulmonary valve was also a bicuspid valve with good coarptation, and no calcification was observed on it (Fig 2). One cm of the main pulmonary artery wall was resected and plicated to reduce the radius diameter.
The pathology of the ascending aorta revealed fibromuscular hyperplasia in the intima, local edema in the deep intima and tunica media, and mild myxoid change. The so-called "cystic medial necrosis" was not observed. The pathology of the pulmonary artery was almost the same as the ascending aorta (ie, un-uniformed distribution of the smooth muscle in the media), staining mucoid substance. Cystic medial necrosis was not observed in the pulmonary artery as well (Fig 3). The pathology of the bicuspid aortic valve showed dense calcification and fibrous thickening.
View larger version (161K):
[in this window]
[in a new window]
|
Fig 3. The pathology of the pulmonary artery showed fibromuscular hyperplasia in the media, local edema in the deep intima and the tunica media, and mild myxoid change. Cystic medial necrosis was not observed. (Elastica Masson stain.)
|
|
The patient was discharged from the hospital uneventfully.
|
Comment
|
|---|
This case report examines two major findings: (1) bilateral bicuspid semilunar valves and (2) simultaneous aneurysms of the ascending aorta and the pulmonary trunk.
Bilateral bicuspid semilunar valves are rare and are usually associated with congenital heart disease [1], mainly associated with Trisomy 18 or Tetralogy of Fallot with absent conal septum. The overall incidence of bilateral bicuspid semilunar valves was 0.75% in the cardiac database of the Children’s Hospital in Boston, Massachusetts. However, this is a cardiac disease database, and thus the actual incidence is expected to be much lower. This patient was more than 60 years of age and no congenital abnormality was found other than the bicuspid valves.
Cases of aneurysm of the ascending aorta accompanied with aneurysm of the pulmonary trunk have been previously reported. There is a report of pulmonary and systemic aneurysms with the widespread arteritis [2]. This report explains the association of pulmonary aneurysm with syphilis, ankylosing spondylitis, rheumatoid disease, rheumatic fever, Reiter’s syndrome, Takayasu’s disease, and giant-cell arteritis. By comparison, our particular case was not associated with any connective tissue disorder, had no evidence of arteritis, and was unrelated to the aforementioned disease and disorders.
The histologic findings of the aneurysmal wall of the pulmonary artery in the previous study were fragmentation or decrease of elastic fiber in media tunica, medial degeneration, increase of collagen fiber, and decrease of smooth muscle cell [3]. However, normal histology of the aneurysmal wall was also reported [4].
Pulmonary aneurysm is usually asymptomatic. Some authors recommend surgical repair to prevent the fatal complication of possible rupture [5].
There are various surgical techniques to repair pulmonary trunk aneurysm, and each has its advantages and disadvantages [3, 4]. This time the pulmonary trunk was plicated to prevent the dilated pulmonary trunk from occupying the pericardial cavity and to reduce the wall tension. Graft replacement for the pulmonary artery was not performed to reduce the cardiopulmonary bypass time and to minimize the usage of the artificial prosthesis.
The cause of the pulmonary trunk aneurysm is explained as: (1) fragility of the media with degeneration and fragmentation of elastic fibers, which includes "cystic medial necrosis," which contributes to the pulmonary artery aneurysm [2, 6]; (2) high-wall tension by LaPlace’s law is raised according to high pulmonary artery pressure and a large radius of the aneurysm, and thus it amplifies the speed of the dilatation [6]; and (3) an abnormal pulmonary valve-like bicuspid valve or single cusp valve, causes the hemodynamic perturbation, even in the absence of stenosis or under normal pulmonary pressure [7, 8]. The main cause of our case was the abnormal pulmonary valve. Pathology of the pulmonary artery that was resected did not demonstrate "cystic medial necrosis," which denies any contribution of the degeneration change of the media to the dilatation of the pulmonary trunk. Hemodynamic turbulence by the bicuspid valve contributed to the dilatation of the artery gradually for long decades even under low pressure.
We believe that this is the first report of a successful surgical repair of the pulmonary artery and ascending aortic aneurysm concomitant with bilateral bicuspid semilunar valves. This case demonstrates the mechanism by which a bicuspid valve causes the dilatation of the artery without cystic medial necrosis, even under low pressure for long decades.
|
References
|
|---|
- Ghez OY, Chetaille PM, Campbell BJ, Van Praagh R, Metras D. Tetralogy of Fallot with aortic valvular stenosis: surgical correction in one case Ann Thorac Surg 2002;73:967-969.[Abstract/Free Full Text]
- Hartley JPR, Dinnen JS, Seaton A. Pulmonary and systemic aneurysms in a case of widespread arteries Thorax 1978;33:493-499.[Abstract/Free Full Text]
- Chen YF, Chiu CC, Lee CS. Giant aneurysm of main pulmonary artery Ann Thorac Surg 1996;62:272-274.[Abstract/Free Full Text]
- Casselman F, Deferm H, Peters P, Vanermen H. Aneurysm of the left pulmonary artery: surgical allograft repair Ann Thorac Surg 1995;60:1423-1425.[Abstract/Free Full Text]
- Kuwaki K, Morishita K, Sato H, Urita R, Abe T. Surgical repair of the pulmonary trunk aneurysm Eur J Cardiothorac Surg 2000;18:535-539.[Abstract/Free Full Text]
- Senbaklavici Ö, Kaneko Y, Bartunek A, Brunner C, et al. Rupture and dissection in pulmonary artery aneurysms: incidence, cause, and treatment—review and case report J Thorac Cardiovasc Surg 2001;121:1006-1008.[Free Full Text]
- Weldtman GR, Dearani JA, Warnes CA. Low pressure giant pulmonary artery aneurysms in the adult: natural history and management strategies Heart 2003;89:1067-1070.[Abstract/Free Full Text]
- Bonderman D, Gharehbaghi-Schnell E, Wollenek G, et al. Mechanisms underlying aortic dilatation in congenital aortic valve malformation Circulation 1999;99:2138-2143.[Abstract/Free Full Text]
Top
Abstract
Introduction
