Pathology
ISSN: 0031-3025 (Print) 1465-3931 (Online) Journal homepage: http://www.tandfonline.com/loi/ipat20
Pulmonary Arterial Dissections and Ruptures: To be Considered in Patients with Pulmonary Arterial Hypertension Presenting with Cardiogenic Shock or Sudden Death V. M. Walley, R. Virmani & M. D. Silver To cite this article: V. M. Walley, R. Virmani & M. D. Silver (1990) Pulmonary Arterial Dissections and Ruptures: To be Considered in Patients with Pulmonary Arterial Hypertension Presenting with Cardiogenic Shock or Sudden Death, Pathology, 22:1, 1-4 To link to this article: https://doi.org/10.3109/00313029009061416
Published online: 06 Jul 2009.
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Pathology (1990). 22. pp. 1-4
PULMONARY ARTERIAL DISSECTIONS AND RUPTURES: TO BE CONSIDERED IN PATIENTS WITH PULMONARY ARTERIAL HYPERTENSION PRESENTING WITH CARDIOGENIC SHOCKORSUDDENDEATH
v. M. W A L L E Y * , R. V I R M A N l t A N D M . D. SILVERS *Universityof Ottawa Heart Institute, Ottawa Civic Hospital, Canada, ?The Armed Forces Institute of Pathology, Washington DC, USA, and $Toronto General Hospital and the University of Toronto, Canada
Summary Four unusual cases of sudden death due to pulmonary arterial hypertension complicated by dissection and/or rupture of the main pulmonary artery are reported. The patients, 3 males and 1 female, ranged from 17 to 77 years old. Each had chronic pulmonary arterial hypertension, marked pulmonary arterial dilation and degenerative medial changes of the large elastic pulmonary arteries. The first patient had a partial thickness tear of the main pulmonary artery with local dissection without external rupture and died of shock. The other three patients died after external rupture of the main pulmonary artery, based on a full thickness tear in one case, a small dissection in another and extensive dissection in the third. In the setting of pulmonary arterial hypertension, dissection, rupture, or dissection and rupture of the pulmonary artery should be considered in the differential diagnosis when patients present in cardiogenic shock or with sudden death.
and pulmonary capillary wedge pressure of 30 mmHg were recorded. The patient died suddenly in asy5tolic arrest. Autopsy confirmed that the patient had micronodular hepatic cirrhosis and changes of portal hypertension. Also noted were severe small vessel changes of idiopathic pulmonary arterial hypertension with obliterative intimal and medial changes, fibrinoid necrosis and arteritis. Larger pulmonary arteries showed marked dilation and atherosclerosis. The pulmonary trunk was up to 10.0 cm in circumference. There were degenerative medial changes in the large pulmonary arteries with fragmentation of elastic fibre, and pooling of mucopolysaccharides, the so-called ‘cystic medial necrosis’ (Fig. 1). The heart showed severe right ventricular hypertrophy. A 6.0 cm ragged intimo-medial tear on the posterior wall of the pulmonary artery ran in the vessel’s long axis (Figs. 2a and 3A) from the annulus of the left pulmonary valve cusp. At the edges of this tear was a local dissection into the deep layers of the media, without further propagation. There w’as moderate hematoma without external rupture in the periarterial soft tissue. Pulienr 2
Key words: Pulmonar) arterial hypertension. dissection. rupturc. aneurysni
Accepted I I J u l y . 1989
This 53-year-old white female was a smoker and had a long history of respiratory abnormality. A year before death heart failure required her
INTRODUCTION Dissection and/or rupture of the pulmonary artery is extremely unusual. However, these diagnoses should be considered when a patient with pulmonary arterial hypertension presents with cardiogenic shock or sudden death. The cases reported here illustrate many interesting aspects of these unusual entities. CASE REPORTS Puiietir I T-his 58-year-old white male had a history of ethanol ahute, hepatic cirrhosis. and a portacaval shunt for rupture of the esophageal varix many years pteviously. More recently he 5uffered shortness of breath and right heart failure. He was admitted on the day he died \ b i t h a \hart history of rub-xiphoid pain, nausea and vomiting; he war noted to he hypotensive and cyanosed. A chest x-ray showed a Nidened mediastinum, but peripheral pulses were normal and an aortic di\section was judged unlikely. An electrocardiogram showed sinu\ tachycardia, right axis deviation and right bundle branch hloch. A Swan-Can/ catheter was inserted and a right atrial mean pressure of 16, right ventricular pressure of H5/9 (mean 66). pulmonary arterial pressure of X0/56
Fig. I Photomicrograph o f the medial degenerative changes seen in the elastic pulmonary arteries of Patient 1 with extensive 105s of elastic lamellae (Movat stain, original magnification x 160).
2
WALLEY et ai.
Pathology (1990), 22, January A large full thickness tear of the main pulmonary artery wall arising 0.5 cm above the left pulmonary valve cusp annulus ran 5.0 cm out towards the bifurcation (Fig. 38). The pericardial cavity was distended with fresh blood and clot arising from a 4.0cm adventitial tear 1 cm above the pulmonary valve.
Patient 3 This 77-year-old white male had a history of systemic arterial hypertension and smoking. He had generalized atherosclerosis manifesting as chronic heart failure, peripheral vascular disease and chronic renal failure. He had considerable pulmonary restriction due to chronic obstructive pulmonary disease. He was admitted to a geriatric service and died suddenly three months after admission. Autopsy confirmed severe generalized atherosclerosis, its effects on the heart and kidneys, and chronic obstructive pulmonary disease. There were changes caused by severe pulmonary arterial hypertension. These appeared to be largely due to numerous small recanalized thromboemboli, along with numerous atheroemboli which apparently arose in the markedly dilated and atherosclerotic larger main elastic pulmonary arteries. Degenerative changes of the elastic media of the pulmonary artery were noted, with ‘cystic medial necrosis’. There was a large old, healed, partial thickness tear arising at the left pulmonary valve cusp annulus and running for about 4.0 cm (fig. 3C), and a more recent tear arising over the anterior cusp and running 4.0cm, associated with a moderately sized intramural hematoma (Fig. 2B). This dissection had ruptured anteriorly to the exterior over a length
R
Fig. 2. (a) The recent intimomedial tear in the pulmonary outflow tract of Patient I is seen extending above the left valve cusp (arrows); (b) A previous, healed, intimal tear is seen in the pulmonary outflow tract above the left valve cusp of Patient 3 (black arrows). A more recent tear above the anterior cusp has associated intramural hematoma (white arrows). admission to hospital. A lung biopsy showed severe pulmonary arterial hypertensive changes, interstitial fibrosis and peribronchial inflammation. The patient was treated with immunosuppressive drugs but had residual severe chronic pulmonary arterial hypertension. She died suddenly. Autopsy confirmed obliterative medial and intimal changes in small vessels of severe idiopathic pulmonary arterial hypertension. There was marked hypertrophy of the right heart. Larger pulmonary arterial branches had marked dilation and showed atherosclerosis and degenerative changes of ‘cystic medial necrosis’.
L A
\ D Fig. 3. Diagrammatic representations of the pulmonary arterial trunk intimal tears are illustrated for Patients 1 to 4, as A to D respectively (in C the crosshatched tear is the old, healed one; right, left and anterior cusps are R, L, and A respectively).
PULMONARY AKTERlAl DISSECTIONS A N D KUPTUKES
Fig. 4. The external rupture site over anterior pulmonary artery is seen from Case 3 (arrow).
of 0.5 cm (Fig. 4 ) and was associated with 650 mL of blood clot and
Pulmonary artery dissections are extremely rare and are generally reported as single Tracking blood or hematoma separates layers of vessel wall but does not usually produce true aneurysm. Most dissections occur as a result of pulmonary arterial hypertension, either acquired, or more often congenital, and related to congenital heart disease with various forms of left to right shunting. Pulmonary arterial dissections usually occur in the presence of medial degeneration, often 'cystic medial necrosis', and diffuse ectasia of pulmonary arterial tree,r.3.4.7although this is not necessarily true of aortic dissections.' In patients with longstanding pulmonary hypertension it is also possible for iatrogenic dissections to result from trauma during pulmonary arterial catheterization.' Most dissections, however, are spontaneous and involve the main trunk of the pulmonary a r t e r ~ . ' . ~ . ~ , ~ . As with aortic dissections, the mortality rate following pulmonary arterial dissection is high and usually due to external rupture with the rupture site near the initial tear. 1 . 3 . 4 . 6 . 7 Patients with pulmonary arterial dissection rarely die from other complications of pulmonary arterial hypertension or develop true aneurysms on the basis of chronic dissection.' As demonstrated here, patients with pulmonary arterial hypertension and diffuse dilation of the pulmonary arterial tree may also show spontaneous rupture of the pulmonary artery with a full thickness tear; such cases may have no associated dissection with intramural tracking of blood, and do not have true aneurysm. As has been suggested for the aorta," this form of tear is most likely part of a spectrum of changes of which may occur in the weakened vessel wall (Fig. 5 ) . With medial degeneration, the wall is weakened and the vessel may dilate. An intimal tear may then extend either laterally as a dissection or straight through as a direct rupture.
5 0 0 mL of fresh blood in the pericardial cavity. Parient 4
This 17-year-old white male had complex congenital cardiac anornalies with Blalock-Taussig and Glenn shunts for transposition o f the great vessels, hypoplastic tricuspid valve, and right ventricle, ventricular septa1 defect and subvalvular and valvular pulnionary and aortic stenoses. 'The patient was admitted with chest pain and had a pericardial friction rub. A day later he died suddenly. Autopsy demonstrated cardiac anomalies and previous site\ of surgery. Small pulmonary vessel changes were thought most likely to be embolic, and were associated with marked reactive hypertensive changes of medial hypertrophy and intimal proliferation. Larger pulmonary arteries were dilated and atherosclerotic with extensive 'cyrtic medial necrosis'. A dissecting hematoma was seen in deep layers of the media of pulmonary arterial trunk with an intimal tear lying posteriorly in rhe pulmonary artery, which was dilated (Fig. 3D). The tear began 3.0 cm above the valve annulus and extended distally for 8.0 cin. The dissection had propagated proximally and distally and had an ill-defined external rupture over the right pulmonary artery, producing hemopericardium and tamponade.
DISCUSSION Aneurysms and dissections, whether in the aorta or the pulmonary artery, are sometimes mistakenly grouped together. However, they represent separate entities, often with distinct pathogeneses.
3
Fig. 5 . The spectrum of changes which may be seen in the large elastic pulmonary arteries wirh pulmonary arterial hypertension is illustrated. (A) The normal intima ( I ) and media (M) may be altered, and (B) develop atherosclerosis and medial degenerative changes as the artery dilates. Tears in intima-media may be full thickness and associated with rupture (C), or be associated with dissection and rupture (D). Dissections need not rupture ( E ) nor may other less extensive tears (F), although they may serve as the background for true aneurysm formation with or without late rupture.
4
Pathology (1990). 22, January
WALLEY et a/.
Dissections themselves may subsequently rupture, or become chronic and hence the basis for further vascular dilation or true aneurysm. True pulmonary arterial aneurysms with localized arterial dilation are also rare. They should not be confused with the diffuse, and sometimes severe, ectasia of the entire pulmonary artery tree which accompanies chronic pulmonary arterial hypertension, as was seen in these four patients. Most true aneurysms are secondary to congenital cardiopulmonary anomalies; occasionally some are related t o infection or inflammation of various causes, to atherosclerosis, to trauma, or more rarely to disorders of connective tissue such as Marfan's syndrome. They may be complicated by r ~ p t u r e . " ~ These patients illustrate that pulmonary arterial dissection and/or rupture should be suspected in patients with chronic pulmonary arterial hypertension of diverse causes, who present with cardiogenic shock or sudden death. With increased awareness of this entity it may be possible to make the diagnosis clinically, for instance with two-dimensional echocardiography,' and in some cases to offer surgical correction, for instance by Dacron grafting. l 2
Anatomical Pathology, Laboratory Medicine, Ottawa Civic Hospital, 1053 Carling Avenue, Ottawa, Ontario. K I Y 4E9, Canada
Address for correspondence: V.M.W.,
References I . Butto F, Luces RV Jr, Edwards JE. Pulmonary arterial aneurysm: a pathologic study of 5 cases. Chest 1987; 91: 237-41. 2. Chiu B, Magi1 A. Idiopathic pulmonary arterial trunk aneurysm
presenting as cor pulmonale: report of a case. Hum Pathol 1985; 16: 947-9. 3. Luchtrath H . Dissecting aneurysm of the pulmonary artery. Virchows Arch (Path Anat) 1981; 391: 241-7. 4. Shilkin KB, Low LP, Chen BTM. Dissecting aneurysm of the pulmonary artery. J Pathol 1969; 98: 25-9. 5. Foord AG, Lewis RD. Primary dissecting aneurysms of peripheral
and pulmonary arteries: dissecting hemorrhage of media. AMA Arch Pathol 1959; 68: 553-77. 6. Nagelsmit M J , Eudlerink F. Dissecting aneurysm of the pulmonary trunk. Am J Cardiol 1986; 58: 660-1. 7. Yamamoto ME, Jones J W , McManus BM. Fatal dissection of the
pulmonary trunk: an obscure consequence of chronic pulmonary hypertension. Am J Cardiov Path 1988; 1: 353-9. 8. Roberts WC. Aortic dissection: anatomy, consequences and causes. Am Heart J 1981; 101: 195-214. 9. Gomez-Arnau J , Montero CG, Luengo C, Gilsanz FJ, Avello F.
ACKNOWLEDGEMENTS The authors thank Dr J. D. Mashburn and Dr D. Friedman of the Shady Grove Adventist Hospital in Rockville, Maryland for supplying Case 1; Dr S. I. Deneka of the Kitchener-Waterloo Hospital, Kitchener, Ontario for Case 2; Dr I . D. Craig, Dr R. A. Armstrong and Dr M. S. Smout from the Victoria Hospital Corporation in London, Ontario for Case 3; and Dr N. A. Clerk from the Etobicoke General Hospital, Rexdale, Ontario for Case 4. They thank Jennifer Vaile for help with the manuscript.
Retrograde dissection and rupture of pulmonary artery after catheter use in pulmonary hypertension. Crit Care Med 1982; 10: 694-5. 10. Murray CA, Edwards J E . Spontaneous laceration of ascending aorta. Circulation 1973; 47: 848-58. 11. Bhaudari AK, Nauda NC. Pulmonary artery aneurysm: echocardiographic features in 5 patients. Am J Cardiol 1984; 53: 1438-41.
12. Williams T E Jr, Schiller M, Craenen J , Hosier DM, Sirak HD.
Pulmonary artery aneurysm: successful excision and replacement of the main pulmonary artery. J Thor Cardiovasc Surg 1971; 62: 63-7.
Undermining the Reputation Some rather elementary people seem t o have the delusion that by undermining the reputation of others their own will be left standing out in bold relief, not realising that such prominence may be of a kind other than is hoped, namely, bad as well as bold, and far from advantageous to their interests. Before judging of what another medical man is reported to have done or said, it is instructive to bear in mind how rumour may transform your actions and remarks out of all recognition. Sir Humphry Rolleston. Aspects ofAge, Life and Diseuse. Kegan Paul, Trench, Trubner & Co. 1938. p195.
ISSN: 0031-3025 (Print) 1465-3931 (Online) Journal homepage: http://www.tandfonline.com/loi/ipat20
Pulmonary Arterial Dissections and Ruptures: To be Considered in Patients with Pulmonary Arterial Hypertension Presenting with Cardiogenic Shock or Sudden Death V. M. Walley, R. Virmani & M. D. Silver To cite this article: V. M. Walley, R. Virmani & M. D. Silver (1990) Pulmonary Arterial Dissections and Ruptures: To be Considered in Patients with Pulmonary Arterial Hypertension Presenting with Cardiogenic Shock or Sudden Death, Pathology, 22:1, 1-4 To link to this article: https://doi.org/10.3109/00313029009061416
Published online: 06 Jul 2009.
Submit your article to this journal
Article views: 10
View related articles
Citing articles: 1 View citing articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=ipat20
Pathology (1990). 22. pp. 1-4
PULMONARY ARTERIAL DISSECTIONS AND RUPTURES: TO BE CONSIDERED IN PATIENTS WITH PULMONARY ARTERIAL HYPERTENSION PRESENTING WITH CARDIOGENIC SHOCKORSUDDENDEATH
v. M. W A L L E Y * , R. V I R M A N l t A N D M . D. SILVERS *Universityof Ottawa Heart Institute, Ottawa Civic Hospital, Canada, ?The Armed Forces Institute of Pathology, Washington DC, USA, and $Toronto General Hospital and the University of Toronto, Canada
Summary Four unusual cases of sudden death due to pulmonary arterial hypertension complicated by dissection and/or rupture of the main pulmonary artery are reported. The patients, 3 males and 1 female, ranged from 17 to 77 years old. Each had chronic pulmonary arterial hypertension, marked pulmonary arterial dilation and degenerative medial changes of the large elastic pulmonary arteries. The first patient had a partial thickness tear of the main pulmonary artery with local dissection without external rupture and died of shock. The other three patients died after external rupture of the main pulmonary artery, based on a full thickness tear in one case, a small dissection in another and extensive dissection in the third. In the setting of pulmonary arterial hypertension, dissection, rupture, or dissection and rupture of the pulmonary artery should be considered in the differential diagnosis when patients present in cardiogenic shock or with sudden death.
and pulmonary capillary wedge pressure of 30 mmHg were recorded. The patient died suddenly in asy5tolic arrest. Autopsy confirmed that the patient had micronodular hepatic cirrhosis and changes of portal hypertension. Also noted were severe small vessel changes of idiopathic pulmonary arterial hypertension with obliterative intimal and medial changes, fibrinoid necrosis and arteritis. Larger pulmonary arteries showed marked dilation and atherosclerosis. The pulmonary trunk was up to 10.0 cm in circumference. There were degenerative medial changes in the large pulmonary arteries with fragmentation of elastic fibre, and pooling of mucopolysaccharides, the so-called ‘cystic medial necrosis’ (Fig. 1). The heart showed severe right ventricular hypertrophy. A 6.0 cm ragged intimo-medial tear on the posterior wall of the pulmonary artery ran in the vessel’s long axis (Figs. 2a and 3A) from the annulus of the left pulmonary valve cusp. At the edges of this tear was a local dissection into the deep layers of the media, without further propagation. There w’as moderate hematoma without external rupture in the periarterial soft tissue. Pulienr 2
Key words: Pulmonar) arterial hypertension. dissection. rupturc. aneurysni
Accepted I I J u l y . 1989
This 53-year-old white female was a smoker and had a long history of respiratory abnormality. A year before death heart failure required her
INTRODUCTION Dissection and/or rupture of the pulmonary artery is extremely unusual. However, these diagnoses should be considered when a patient with pulmonary arterial hypertension presents with cardiogenic shock or sudden death. The cases reported here illustrate many interesting aspects of these unusual entities. CASE REPORTS Puiietir I T-his 58-year-old white male had a history of ethanol ahute, hepatic cirrhosis. and a portacaval shunt for rupture of the esophageal varix many years pteviously. More recently he 5uffered shortness of breath and right heart failure. He was admitted on the day he died \ b i t h a \hart history of rub-xiphoid pain, nausea and vomiting; he war noted to he hypotensive and cyanosed. A chest x-ray showed a Nidened mediastinum, but peripheral pulses were normal and an aortic di\section was judged unlikely. An electrocardiogram showed sinu\ tachycardia, right axis deviation and right bundle branch hloch. A Swan-Can/ catheter was inserted and a right atrial mean pressure of 16, right ventricular pressure of H5/9 (mean 66). pulmonary arterial pressure of X0/56
Fig. I Photomicrograph o f the medial degenerative changes seen in the elastic pulmonary arteries of Patient 1 with extensive 105s of elastic lamellae (Movat stain, original magnification x 160).
2
WALLEY et ai.
Pathology (1990), 22, January A large full thickness tear of the main pulmonary artery wall arising 0.5 cm above the left pulmonary valve cusp annulus ran 5.0 cm out towards the bifurcation (Fig. 38). The pericardial cavity was distended with fresh blood and clot arising from a 4.0cm adventitial tear 1 cm above the pulmonary valve.
Patient 3 This 77-year-old white male had a history of systemic arterial hypertension and smoking. He had generalized atherosclerosis manifesting as chronic heart failure, peripheral vascular disease and chronic renal failure. He had considerable pulmonary restriction due to chronic obstructive pulmonary disease. He was admitted to a geriatric service and died suddenly three months after admission. Autopsy confirmed severe generalized atherosclerosis, its effects on the heart and kidneys, and chronic obstructive pulmonary disease. There were changes caused by severe pulmonary arterial hypertension. These appeared to be largely due to numerous small recanalized thromboemboli, along with numerous atheroemboli which apparently arose in the markedly dilated and atherosclerotic larger main elastic pulmonary arteries. Degenerative changes of the elastic media of the pulmonary artery were noted, with ‘cystic medial necrosis’. There was a large old, healed, partial thickness tear arising at the left pulmonary valve cusp annulus and running for about 4.0 cm (fig. 3C), and a more recent tear arising over the anterior cusp and running 4.0cm, associated with a moderately sized intramural hematoma (Fig. 2B). This dissection had ruptured anteriorly to the exterior over a length
R
Fig. 2. (a) The recent intimomedial tear in the pulmonary outflow tract of Patient I is seen extending above the left valve cusp (arrows); (b) A previous, healed, intimal tear is seen in the pulmonary outflow tract above the left valve cusp of Patient 3 (black arrows). A more recent tear above the anterior cusp has associated intramural hematoma (white arrows). admission to hospital. A lung biopsy showed severe pulmonary arterial hypertensive changes, interstitial fibrosis and peribronchial inflammation. The patient was treated with immunosuppressive drugs but had residual severe chronic pulmonary arterial hypertension. She died suddenly. Autopsy confirmed obliterative medial and intimal changes in small vessels of severe idiopathic pulmonary arterial hypertension. There was marked hypertrophy of the right heart. Larger pulmonary arterial branches had marked dilation and showed atherosclerosis and degenerative changes of ‘cystic medial necrosis’.
L A
\ D Fig. 3. Diagrammatic representations of the pulmonary arterial trunk intimal tears are illustrated for Patients 1 to 4, as A to D respectively (in C the crosshatched tear is the old, healed one; right, left and anterior cusps are R, L, and A respectively).
PULMONARY AKTERlAl DISSECTIONS A N D KUPTUKES
Fig. 4. The external rupture site over anterior pulmonary artery is seen from Case 3 (arrow).
of 0.5 cm (Fig. 4 ) and was associated with 650 mL of blood clot and
Pulmonary artery dissections are extremely rare and are generally reported as single Tracking blood or hematoma separates layers of vessel wall but does not usually produce true aneurysm. Most dissections occur as a result of pulmonary arterial hypertension, either acquired, or more often congenital, and related to congenital heart disease with various forms of left to right shunting. Pulmonary arterial dissections usually occur in the presence of medial degeneration, often 'cystic medial necrosis', and diffuse ectasia of pulmonary arterial tree,r.3.4.7although this is not necessarily true of aortic dissections.' In patients with longstanding pulmonary hypertension it is also possible for iatrogenic dissections to result from trauma during pulmonary arterial catheterization.' Most dissections, however, are spontaneous and involve the main trunk of the pulmonary a r t e r ~ . ' . ~ . ~ , ~ . As with aortic dissections, the mortality rate following pulmonary arterial dissection is high and usually due to external rupture with the rupture site near the initial tear. 1 . 3 . 4 . 6 . 7 Patients with pulmonary arterial dissection rarely die from other complications of pulmonary arterial hypertension or develop true aneurysms on the basis of chronic dissection.' As demonstrated here, patients with pulmonary arterial hypertension and diffuse dilation of the pulmonary arterial tree may also show spontaneous rupture of the pulmonary artery with a full thickness tear; such cases may have no associated dissection with intramural tracking of blood, and do not have true aneurysm. As has been suggested for the aorta," this form of tear is most likely part of a spectrum of changes of which may occur in the weakened vessel wall (Fig. 5 ) . With medial degeneration, the wall is weakened and the vessel may dilate. An intimal tear may then extend either laterally as a dissection or straight through as a direct rupture.
5 0 0 mL of fresh blood in the pericardial cavity. Parient 4
This 17-year-old white male had complex congenital cardiac anornalies with Blalock-Taussig and Glenn shunts for transposition o f the great vessels, hypoplastic tricuspid valve, and right ventricle, ventricular septa1 defect and subvalvular and valvular pulnionary and aortic stenoses. 'The patient was admitted with chest pain and had a pericardial friction rub. A day later he died suddenly. Autopsy demonstrated cardiac anomalies and previous site\ of surgery. Small pulmonary vessel changes were thought most likely to be embolic, and were associated with marked reactive hypertensive changes of medial hypertrophy and intimal proliferation. Larger pulmonary arteries were dilated and atherosclerotic with extensive 'cyrtic medial necrosis'. A dissecting hematoma was seen in deep layers of the media of pulmonary arterial trunk with an intimal tear lying posteriorly in rhe pulmonary artery, which was dilated (Fig. 3D). The tear began 3.0 cm above the valve annulus and extended distally for 8.0 cin. The dissection had propagated proximally and distally and had an ill-defined external rupture over the right pulmonary artery, producing hemopericardium and tamponade.
DISCUSSION Aneurysms and dissections, whether in the aorta or the pulmonary artery, are sometimes mistakenly grouped together. However, they represent separate entities, often with distinct pathogeneses.
3
Fig. 5 . The spectrum of changes which may be seen in the large elastic pulmonary arteries wirh pulmonary arterial hypertension is illustrated. (A) The normal intima ( I ) and media (M) may be altered, and (B) develop atherosclerosis and medial degenerative changes as the artery dilates. Tears in intima-media may be full thickness and associated with rupture (C), or be associated with dissection and rupture (D). Dissections need not rupture ( E ) nor may other less extensive tears (F), although they may serve as the background for true aneurysm formation with or without late rupture.
4
Pathology (1990). 22, January
WALLEY et a/.
Dissections themselves may subsequently rupture, or become chronic and hence the basis for further vascular dilation or true aneurysm. True pulmonary arterial aneurysms with localized arterial dilation are also rare. They should not be confused with the diffuse, and sometimes severe, ectasia of the entire pulmonary artery tree which accompanies chronic pulmonary arterial hypertension, as was seen in these four patients. Most true aneurysms are secondary to congenital cardiopulmonary anomalies; occasionally some are related t o infection or inflammation of various causes, to atherosclerosis, to trauma, or more rarely to disorders of connective tissue such as Marfan's syndrome. They may be complicated by r ~ p t u r e . " ~ These patients illustrate that pulmonary arterial dissection and/or rupture should be suspected in patients with chronic pulmonary arterial hypertension of diverse causes, who present with cardiogenic shock or sudden death. With increased awareness of this entity it may be possible to make the diagnosis clinically, for instance with two-dimensional echocardiography,' and in some cases to offer surgical correction, for instance by Dacron grafting. l 2
Anatomical Pathology, Laboratory Medicine, Ottawa Civic Hospital, 1053 Carling Avenue, Ottawa, Ontario. K I Y 4E9, Canada
Address for correspondence: V.M.W.,
References I . Butto F, Luces RV Jr, Edwards JE. Pulmonary arterial aneurysm: a pathologic study of 5 cases. Chest 1987; 91: 237-41. 2. Chiu B, Magi1 A. Idiopathic pulmonary arterial trunk aneurysm
presenting as cor pulmonale: report of a case. Hum Pathol 1985; 16: 947-9. 3. Luchtrath H . Dissecting aneurysm of the pulmonary artery. Virchows Arch (Path Anat) 1981; 391: 241-7. 4. Shilkin KB, Low LP, Chen BTM. Dissecting aneurysm of the pulmonary artery. J Pathol 1969; 98: 25-9. 5. Foord AG, Lewis RD. Primary dissecting aneurysms of peripheral
and pulmonary arteries: dissecting hemorrhage of media. AMA Arch Pathol 1959; 68: 553-77. 6. Nagelsmit M J , Eudlerink F. Dissecting aneurysm of the pulmonary trunk. Am J Cardiol 1986; 58: 660-1. 7. Yamamoto ME, Jones J W , McManus BM. Fatal dissection of the
pulmonary trunk: an obscure consequence of chronic pulmonary hypertension. Am J Cardiov Path 1988; 1: 353-9. 8. Roberts WC. Aortic dissection: anatomy, consequences and causes. Am Heart J 1981; 101: 195-214. 9. Gomez-Arnau J , Montero CG, Luengo C, Gilsanz FJ, Avello F.
ACKNOWLEDGEMENTS The authors thank Dr J. D. Mashburn and Dr D. Friedman of the Shady Grove Adventist Hospital in Rockville, Maryland for supplying Case 1; Dr S. I. Deneka of the Kitchener-Waterloo Hospital, Kitchener, Ontario for Case 2; Dr I . D. Craig, Dr R. A. Armstrong and Dr M. S. Smout from the Victoria Hospital Corporation in London, Ontario for Case 3; and Dr N. A. Clerk from the Etobicoke General Hospital, Rexdale, Ontario for Case 4. They thank Jennifer Vaile for help with the manuscript.
Retrograde dissection and rupture of pulmonary artery after catheter use in pulmonary hypertension. Crit Care Med 1982; 10: 694-5. 10. Murray CA, Edwards J E . Spontaneous laceration of ascending aorta. Circulation 1973; 47: 848-58. 11. Bhaudari AK, Nauda NC. Pulmonary artery aneurysm: echocardiographic features in 5 patients. Am J Cardiol 1984; 53: 1438-41.
12. Williams T E Jr, Schiller M, Craenen J , Hosier DM, Sirak HD.
Pulmonary artery aneurysm: successful excision and replacement of the main pulmonary artery. J Thor Cardiovasc Surg 1971; 62: 63-7.
Undermining the Reputation Some rather elementary people seem t o have the delusion that by undermining the reputation of others their own will be left standing out in bold relief, not realising that such prominence may be of a kind other than is hoped, namely, bad as well as bold, and far from advantageous to their interests. Before judging of what another medical man is reported to have done or said, it is instructive to bear in mind how rumour may transform your actions and remarks out of all recognition. Sir Humphry Rolleston. Aspects ofAge, Life and Diseuse. Kegan Paul, Trench, Trubner & Co. 1938. p195.
