HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Subrato J. Deb Kenton J. Zehr Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Deb, S. J. Articles by Shields, R. C. Search for Related Content PubMed PubMed Citation Articles by Deb, S. J. Articles by Shields, R. C.

Ann Thorac Surg 2005;80:1500-1502
© 2005 The Society of Thoracic Surgeons

---

Case report

Idiopathic Pulmonary Artery Aneurysm

^a Division of Cardiovascular Surgery, Rochester, Minnesota
^b Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota

Accepted for publication April 1, 2004.

^_* Address reprint requests to Dr Zehr, Mayo Clinic, 200 First St, SW, Rochester, MN55905 (Email: zehr.kenton{at}mayo.edu).

	Abstract

Top Abstract Introduction Comment References

 
A case of idiopathic pulmonary artery aneurysm is presented along with a review of our experience of this rare condition. These entities may have an association with cystic medial degeneration of the arterial wall and are subject to the same complications as aortic aneurysms.

	Introduction

Top Abstract Introduction Comment References

 
Pulmonary artery aneurysm (PAA) is a rare condition that may be congenital or acquired [1]. Idiopathic PAAs comprise only a few case reports. These aneurysms can grow to immense proportions before diagnosis. Pulmonary artery aneurysms associated with congenital lesions are often treated concomitantly with the underlying anomaly. In contrast, the management of idiopathic PAA is not defined. As in aortic aneurysm disease, it can be assumed that the same hemodynamic forces promote growth of the PAA based on Laplace's law even in the lower pressure pulmonary circuit. Some PAAs have weakened medial elastic layers of the arterial wall [2], conceivably increasing the risk of rupture or dissection. We review a recent case of idiopathic PAA and our experience with this uncommon entity.

A 62-year-old man presented with an asymptomatic PAA that was discovered on chest roentgenogram (Fig 1). The patient was asymptomatic. Inflammatory, infectious, and traumatic causes were ruled out. Physical examination revealed a tall (184 cm) human without features of connective tissue disorder. No murmurs were auscultated. Transthoracic echocardiogram revealed normal biventricular function. The pulmonary artery systolic pressure was elevated at 46 mm Hg and there was mild pulmonary valve insufficiency. Computed tomographci scan showed a 6.5 cm PAA with dilation extending to both proximal arteries (Fig 2).

View larger version (150K): [in this window] [in a new window]   Fig 1. Pulmonary artery chest roentgenogram demonstrating a mass in the left hilum.

View larger version (133K): [in this window] [in a new window]   Fig 2. Three-dimensional reconstruction of chest computed tomography revealing diffuse aneurysmal dilatation of the pulmonary outflow tract and each main pulmonary artery.

Pathologic examination of the resected pulmonary artery revealed cystic medial degeneration (CMD). The patient had an uneventful recovery.

From November 1977 to November 2002, 51 patients have had a repair of PAA at our institution. Forty-six patients had associated congenital anomalies. The remaining 5 patients (including the patient presented) had surgical treatment of idiopathic PAA. The 3 women and 2 men had a median age of 57 years (range, 31 to 66 years old). None of these patients exhibited stigmata of a connective tissue disorder. Three patients had chest roentgenograms that incorrectly identified the PAA as a hilar or mediastinal mass. Two patients were asymptomatic and 3 presented with dyspnea at presentation. One patient also had hoarseness due to stretching of the left recurrent laryngeal nerve. The median aneurysm size was 9 cm (range, 6 to 12 cm). Methods of treatment of the aneurysm varied and included reduction arterioplasty in 3 of 5 patients. This was done by removing an elliptical portion of the anterior wall of the involved artery, followed by primary closure, which effectively reduced the caliber of the vessel. In 2 patients, the main pulmonary artery was replaced with a 28-mm pulmonary allograft and a 26-mm Hancock valved conduit (Medtronic Inc, Minneapolis, MN). Two patients had pulmonary valve replacement for insufficiency. Three patients had histopathologic confirmation of CMD of the artery.

There was no operative mortality and 1 early death among the 5 patients (20%). This patient presented with congestive heart failure due to severe mitral valvular stenosis from rheumatic heart disease and died from low cardiac output syndrome and multiorgan failure. The median hospital stay was 6 days (range, 4 to 11 days) and the median follow-up was 22 months (range, 4 to 60 months). The 4 surviving patients are alive and well at follow-up without evidence of recurrent dilation of the pulmonary artery.

	Comment

Top Abstract Introduction Comment References

 
Idiopathic PAAs are rare anomalies with poorly understood pathogenesis. Pulmonary artery aneurysms were found in approximately 1 of 14,000 autopsies as reported by Deterling and Claggett [3]. The majority were noted in the main pulmonary artery. Arom and colleagues [4] reported on the causative or associated factors of PAAs. The most common cause was an association with congenital cardiac defects as noted in 47%, with a patent ductus arteriosus in most. Syphilis was the second most common cause, accounting for one third of the cases. Last, atherosclerotic, degenerative, and traumatic causes completed the list. Importantly, these authors reported degenerative changes of the arterial media, specifically fragmentation of the elastic media in 3% of their cases [4]. Caralps and colleagues also proposed the importance of cystic medial weakening in the pathogenesis of PAAs [2]. An association between CMD and increased hemodynamic forces leading to aneurysm formation was postulated, even in the absence of a bona fide connective tissue disorder [2]. In our experience, CMD was the most common pathology and likely the most important factor in the pathogenesis of idiopathic PAAs.

Common symptoms of PAAs include dyspnea, cough, and chest pain. Arom and colleagues [4] noted exertional dyspnea in 69% of PAAs. If the pulmonary valve is incompetent, signs of right heart failure may manifest. Three of our patients (60%) presented with right ventricular dysfunction with variable degrees of pulmonary valve regurgitation. Only 1 of our 5 patients had symptoms specifically due to the aneurysm. This patient had dyspnea and hoarseness due to stretching of the recurrent laryngeal nerve.

These aneurysms can grow to an impressive size before identification as noted by our median size of 9 cm. Often found on chest roentgenograms and misinterpreted as hilar or mediastinal masses, further radiologic evaluation is necessary to make the correct diagnosis. All 5 of our patients had abnormal chest roentgenograms.

There is no prospective data on the natural history of idiopathic PAAs. Some PAAs become symptomatic and undergo repair, whereas others continue to grow until discovered. As noted earlier, idiopathic PAAs are subjected to the same hemodynamic forces as aortic aneurysms, and in the presence of CMD, these aneurysms are prone to dissection or rupture. Lopez-Candales and colleagues [5] described pulmonary artery dissection in a patient with a 6 x 5.5 cm aneurysm. Large aneurysms can become symptomatic due to local compressive phenomenon [2, 6]. Progression to complications can occur in the lower pressure pulmonary system. In the setting of right ventricular dysfunction with pulmonary valve insufficiency, the decision to operate is easier. If there is evidence of right ventricular dysfunction or elevated pulmonary artery pressures, we recommend surgical repair. It is unclear if there is a size hinge point similar to aortic aneurysms in which the risk of complication increases. The literature of ascending aortic aneurysms supports 6 cm as the lower limit of safe observation. Given the substrate of CMD, as found in several of our patients, we would favor 6 cm as the lower limit of surveillance for idiopathic PAAs.

Various techniques of repair have been described, including aneurysm plication (aneurysmorrhaphy or arterioplasty), pericardial patch reconstruction, and interposition grafting with allografts or synthetic textile grafts [2, 5–8]. Three of our patients (75%) had arterioplasty with resection and 2 had excision with interposition replacement of the main pulmonary artery. In our experience, replacement of the main pulmonary artery or arterial resection with reduction arterioplasty were equally effective.

Idiopathic PAAs are rare entities often found incidentally. There is an association between this subgroup of PAA and CMD of the arterial wall. Surgical treatment can be offered with minimal morbidity and mortality in otherwise healthy patients. Based on this premise, we recommend that enlarged aneurysms (>6 cm) and those that are symptomatic of any size should be repaired, particularly in patients with right ventricular dysfunction or elevated pulmonary artery pressures.

	References

Top Abstract Introduction Comment References

 

1. Tsui EYK, Chung YK, Chow L, Chau LF, Yu SK, Chan JHM. Idiopathic pulmonary artery aneurysmdigital subtraction pulmonary angiography grossly underestimates the size of the aneurysm. J Clin Imaging 2001;25:178-180.
2. Caralps JM, Bonnin JO, Oter R, Aris A. True aneurysm of the main pulmonary arterysurgical correction. Ann Thorac Surg 1978;25:561-563.[Abstract]
3. Deterling RA, Claggett OT. Aneurysm of the pulmonary arterya review of the literature and report of a case. Am Heart J 1947;34:471-498.
4. Arom KV, Richardson JD, Grover FL, Ferris G, Trinkle K. Pulmonary artery aneurysm Am Surgeon 1978;44:688-692.[Medline]
5. Lopez-Candales A, Kleiger RE, Aleman-Gomez J, Kouchoukos NT. Pulmonary artery aneurysmreview and case report. Clin Cardiol 1995;18:738-740.[Medline]
6. Nair KKS, Cobanoglu AM. Idiopathic main pulmonary artery aneurysm Ann Thorac Surg 2001;71:1688-1690.[Abstract/Free Full Text]
7. Gruber PJ, Askin FB, Heitmiller RF. Pulmonary artery aneurysm in a pregnant woman Ann Thorac Surg 2001:1023-1025.
8. Hamawy AH, Cartledge RG, Girardi LN. Graft repair of a pulmonary artery aneurysm Heart Surg Forum 2002;5:396-398.[Medline]

This article has been cited by other articles:

				G. Arnaoutakis, L. Nwakanma, and J. Conte Idiopathic pulmonary artery aneurysm treated with surgical correction and concomitant coronary artery bypass grafting. Ann. Thorac. Surg., July 1, 2009; 88(1): 273 - 275. [Abstract] [Full Text] [PDF]

				X.-H. Hao, J.-H. Liu, C.-M. Bao, J. Yang, and Y.-Q. Lai Severe calcified saccular pulmonary artery aneurysm. Ann. Thorac. Surg., May 1, 2009; 87(5): 1587 - 1589. [Abstract] [Full Text] [PDF]

				N. Vistarini, S. Aubert, I. Gandjbakhch, and A. Pavie Surgical treatment of a pulmonary artery aneurysm Eur. J. Cardiothorac. Surg., June 1, 2007; 31(6): 1139 - 1141. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Subrato J. Deb Kenton J. Zehr Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Deb, S. J. Articles by Shields, R. C. Search for Related Content PubMed PubMed Citation Articles by Deb, S. J. Articles by Shields, R. C.