Dissecting aneurysm (hematoma) limited to coronary artery

Dissecting Aneurysm (Hematoma) Limited to Coronary Artery A Clinicopathologic

BERNADINE

Ii.

BULKLEY,

WILLIAM

C. ROBERTS,

Bethesda.

Maryland

Study of Six Patients

M.D.

M.D.

Clinical and cardiovascular necropsy features are described in six patients (five women) with dissecting aneurysm (hematoma) limited to coronary artery. The coronary dissections occurred spontaneously in two patients, and an intimal or adventitial tear was not identified in either. Four patients had iatrogenie-induced coronary arterial dissections; three had had aortic valve replacement, and the remaining one had a saphenous vein grafted to the dissected coronary artery. Coronary arterial dissection is an infrequently recognized complication of cardiac surgery and a commonly unrecognized cause of coronary arterial luminal narrowing and sudden death. Although believed to be universally fatal, coronary dissection was not fatal in one of our six patients in whom an occlusive chronic (healed) medial dissection and a healed myocardial infarction were observed. Clinical and morphologic features of dissecting aneurysm (hematoma) of the aorta are well recognized. Frequently, dissecting aneurysm of the aorta extends into the coronary artery causing luminal narrowing. Dissecting aneurysm may involve the coronary artery, however, without associated dissection of the aorta. The clinical and morphologic features of isolated coronary arterial dissection are not well known. We attempt to clarify these features by describing clinical and necropsy observations in six necropsy patients in whom the acute dissecting aneurysm was limited to coronary artery. PATIENTS STUDIED Pertinent information on the six patients is summarized in Table I, The coronary dissections occurred spontaneously in two patients (Cases 1 and 2) and were iatrogenically produced in the other four

From the Section of Pathology, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland 20014. Requests for reprints should be addressed to: Dr. William C. Roberts, Bldg. lOA-Room 3E-30, National Heart and Lung Institute, National Institutes of Health, Bethesda, Maryland 20014. Manuscript accepted June 11,1973.

(Cases 3, 4, 5 and 6). Of the two who had a natural death, one died suddenly but had had congestive heart failure previously from a large atrial septal defect; the second had never had evidence of cardiac dysfunction and died of osteogenic sarcoma with pulmonary metastases. At necropsy, neither patient had evidence of myocardial necrosis, replacement fibrosis or significant luminal narrowing of the coronary arteries by atherosclerotic plaques; however, the lumens of

branches

dissecting

of the

hematomas

December 1973

left

coronary

artery

in both (Figures

were

severely

narrowed

by

1 through 5).

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HEMATOMA LIMITED TO CORONARY ARTERY-BULKLEY,

TABLE I

Isolated

Medial Dissection

ROBERTS

of Coronary

Clinical and Anatomic

Artery:

Data in Six Patients %

Case No.

Age00 and Sex

Patient

Associated Cardiac Disease

Cardiac Operation

Heart Weight Causeof Death

(8)

Maximal % CA Maximal Luminal Luminal Narrowing Narrowingby by Medial Old Plaque Hematoma CA Dissected <25

>75

350 310

LM, LAD LC, LM LAD, LM LAD, LC

<25 >75

>75 <25

700

R

25-50

>75

600

LC

<25

>75

385

LC

>75

<25

1

A4417

66, F

ASD

0

Sudden

450

2 3

A61-289 A72-235

67,F 45, F

0 AS, MS

4

A70-249

54, F

AS

0 MVR, AVR AVR

5

GT71A-321

48, F

AS, MI

AVR

6

A72-209

54, M

Angina pectoris

SVBG

Sarcoma Prosthetic stenosis Prosthetic stenosis Prosthetic stenosis Operation

NOTE: AP = angina pectoris; AS = aortic stenosis; ASD = atrial septal defect; AVR = aortic valve replacement; CA = coronary artery; LAD = left anterior descending; MVR = mitral valve replacement; R = right; SVBG = saphenous vein bypass graft.

All four patients with iatrogenically-induced coronary dissections (Cases 3, 4, 5 and 6), had had cardiac operations: aortic valve replacement in three cases and coronary arterial bypass grafting in one case. Two patients (Cases 3 and 4) with replaced valves died 1 and 5 days, respectively, after operation from low cardiac output secondary to prosthetic aortic stenosis: in one patient (Case 3) (Figure 6) severe atherosclerosis was present, and the medial dissection caused only minimal additional luminal narrowing; in the other patient (Case 4) (Figure 7) atherosclerosis was minimal, and the lumen of the right coronary artery was nearly completely occluded by a medial hematoma. One patient (Case 5) (Figure 8). in whom the aortic valve had been replaced 4 years earlier, died of congestive cardiac failure secondary to an obstructing thrombus on the trileaflet Hufnagel valve. Six months earlier she had had an acute myocardial infarct. At necropsy, the left circumflex branch was severely narrowed by an organized medial hematoma; the lumens of the other coronary arteries were widely patent. The anterior wall of left ventricle was severely scarred. Our only male patient (Case 6) had intractable angina pectoris secondary to severe coronary atherosclerosis, and he died in the operating room after aortocoronary-saphenous-vein bypass grafting (Figure 9). At necropsy, his extraluminal coronary arteries were diffusely and severely narrowed by old plaques. A medial hematoma was present in the left circumflex coronary artery both proximal and distal to the point of anastomosis. An intimal tear was identified at the anatomotic site, and the medial hematoma did not cause significant luminal narrowing. None of the six patients had histories of syphilis, systemic hypertension or chest trauma, or associated dissection of the aorta.

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COMMENTS

Review of the records of 40 previously described necropsy patients [l-23] and of our six discloses

that isolated arterial dissection usually affects younger adults (average age 43 years), women more than men (36 to lo), usually (85 per cent) causes sudden death without histologic evidence of myocardial infarction, and has never been diagnosed during life. Isolated coronary arterial dissection is usually not associated with systemic hypertension, congenital cardiovascular malformations or significant coronary arterial atherosclerosis. Women are particularly prone to coronary dissection during the peripartum period [2,911,15,23]. Of 36 women who died of coronary dissection, one-third were in the peripartum state; most were multiparous and in their later childbearing years. Dissecting aneurysm of the aorta is also more frequent during pregnancy. Pulmonary parenchymal disease may be increased in patients with primary coronary dissection. It occurred in 9 of the tabulated 46 patients. Although it may produce medial arterial degeneration in patients with sustained hypotension [24], hypoxia from chronic pulmonary disease is not a known cause of medial arterial dissection. Trauma may lead to coronary arterial dissection (Table II). Two of the 40 previously reported patients had chest trauma: one had been kicked by a horse [ll], and the other had undergone cardiac resuscitation [21]. latrogenic trauma may go unrecognized: four of our six patients had had cardiac operations, and canulas had been inserted

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L. CIRCUMFLEX

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INTRAMURAL L. ANTERIOR

-

DESCENDING-

HEMATOMA

Figure 1. Case 1. Pattern of left coronary arterial dissection in a 66 year old woman (MHCMH A441 7) who died suddenly. Her coronary arteries are shown in transverse section in Figure 2.

Figure 2. Case 1. This dissecting hematoma involved the outer media of left anterior descending (b), left marginal (c) and left circumflex (d) coronary arteries causing considerable luminal narrowing, which most likely led to her death, which was sudden. The right coronary artery (a) was not dissected and the coronary arteries and aorta contained few atherosclerotic plaques. Movat stain; original magnification each X 16, reduced by 21 per cent.

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L. CIRCUMFLEX

-

INT RAMURAL HEMATOMA

L.MARGINAL L. ANTERIOR

Case 2. Pattern of dissection of left coronary Figure 3. whose coronary arteries are shown in Figure 4.

DESCENDING

artery in patient

Figure 4. C&e 2. Dissection of left anterior descending and left margma, coronary arteries in a 67 year old woman (A61-289) who had metastatic cancer of the lung and was found dead in bed. At necropsy, the coronary arteries contained few atherosclerotic plaques (a), and the left marginal branch (b) was totally occluded by a hematoma which had separated media from external elastic membrane. Although nonocclusive, the medial hematoma also was present in the proximal left anterior descending coronary artery (c). Movat stain; original magnification X 27 (a), X 38 (b) and X 27 (cl, each reduced by 30 per cent.

into the coronary arteries in three. Isolated coronary arterial dissection from trauma by canulas has been reported previously [25-271. In two of the three patients, rigid framed aortic prostheses, both of which were severely stenotic, had been utilized. The “supravalvular” stenosis may have led to coronary arterial hypertension (Figure 10) which contributed to the coronary dissection, just as systemic hypertension usually underlies dissec-

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tion of the aorta. An intimal-medial tear was identified at the site of anastomosis of a saphenous vein bypass graft in one of our patients (Case 6). This complication of the saphaneous vein bypass procedure has not been described previously. Dissection isolated to the coronary artery is a rare cause of fatal myocardial ischemia (Table I II). Survival after coronary arterial dissection is possible if the narrowing of the true lumen by the

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cl. and X 400 (dl, each reduced by 20per cent.

medial hemorrhage is slight so that myocardial &hernia does not occur, or, if severe, the myocardial infarct heals. To our knowledge, our Case 5 is the first reported of the latter situation, and our Cases 3 and 6 are examples of the former. The dissections in the latter two patients would have been overlooked had not the entire coronary tree been examined histologically [28]. Morphologically, coronary arterial dissections are relatively uniform. The left coronary artery and its branches are most frequently involved (39 left, 5 right, 1 both). The hematoma characteristically is present in the outer media, but often separates the entire media from the external elastic membrane. Small fragments of media usually, how-

December

ever, remain adherent to external elastic membrane. In contrast, aortic wall dissections (Tabie IV) always occur entirely within the media and virtually never between the media and external elastic membrane. Although rarely documented by convincing photomicrographs, intimal tears have been described in 7 of 40 previously reported coronary dissections. Despite examination of numerous sections of coronary artery, the site of dissection was found in only one (Case 6) of our six patients, and in him the dissection was produced by operation (bypass graft). Cystic spaces (4 in 41), smooth muscle degeneration and elastic tissue disruption also have been mentioned [2-3,17,22] as important factors producing coronary dissec-

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Figure 6. Case 3. Acute isolated dissection of coronary artery after aortic valve repfacement. This 45 year old woman (A 72-235) with type IV hyperlipoproteinemia and rheumatic valvular disease underwent valve replacement with a Starr-Edwards prosthesis 24 hours before death from low cardiac output syndrome. At necropsy, all three struts of the aortic valve prosthesis (d) contacted aorta and severely impaired movement of the poppet. Histologic study of the entire coronary arterial tree disclosed moderate atherosclerosis. In addition, an outer medial dissection was present in left circumflex (a), left anterior descending (b) and left main coronary arteries (c). The dissecting hematoma produced only mild luminal narrowing. The aorta, proximal left main and right coronary arteries were not dissected. Cannulation of coronary artery and prosthetic stenosis may have been factors leading to the dissection. Movat stain; original magnification X 38 (a), X 42 (b) and X 26 (c), each reduced by 20 per cent.

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Figure 7. Case 4. Dissection involving right coronary artery in a 54 year old woman (A70-249). Histologic transverse section through the artery (a) demonstrates a hematoma which has split off media from external elastic membrane. The hematoma compressed the flexible portion of arterial wall (i.e., that part not involved by atherosclerotic plaque) and caused severe luminal narrowing. This lesion may be diagnosed by gross inspection of the transversely cut coronary artery as shown (b). Hematoxylin and eosin stain: original manification X 23, reduced by 75 per cent.

Figure 8. Case 5. Healed or chronic coronary arterial dissection in a 48 year old woman (GT 71A-321) who had had an acute myocardial infarction 6 months before death. At necropsy, a healed dissection of left circumflex coronary artery (a and b) and a healed anterior myocardial infarction (d) were present. An organized hematoma, located in the outer media, significantly narrowed the lumens. The organized hematoma was composed mostly of fibrous tissue (c). A small recanalized channel was present in the healed hematoma (b). Movat stain; original magnification X 45 (a). Hematoxylin and eosin stain; original magnification X 45 (b), X 320 (c) and X 16 (d). All reduced by 31 per cent.

HEMATOMA LIMITED TO CORONARY ARTERY-BULKLEY,

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coronary arterial dissection in a 54 year old diabetic man (A72-209) who had Figure 9. Case 6. latrogenic aortocoronary saphenous vein bypass grafts to the left anterior descending and left circumflex coronary arteries. (a), the patient died 8 hours after operation from refractory low cardiac output. At necropsy, the coronary arteries were severely narrowed by atherosclerotic plaques. Shown are histologic sections of left anterior descending (b) and left circumflex (c) coronary arteries proximal to the grafts. A medial hematoma was present in left circumflex coronary artery proximal (d) and distal (e) to the anastomosis. A closer view of the vessel wall (f) shows intima (I), media (M) and adventitia (A) with a dissected hematoma within the outer media. L = vascular lumen, PT = pulX 35 (b), X 23 (cl; X monary trunk, RV = right ventricle, LV = left ventricle. Movat stains; original magnification 38 (d), X 27 (e) and X 140 (f). All reduced by 20per cent.

tion. We observed small cystic medial spaces in all six patients but were unable to implicate them as causes of the dissections. In most necropsy reports, the coronary arteries involved by dissection contain few atherosclerotic plaques, possibly because acute coronary dissections affecting near normal arteries are more apt to be lethal. Four of our six patients had nearly

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normal coronary arteries, and medial hematomas severely narrowed their lumens; each of the two patients (Cases 3 and 6) with severe atherosclerosis had minimal narrowing of the lumens by medial hematomas. The nonpliable rigid intima in the latter appears to protect against luminal compression by the medial hematoma. The more frequent occurrence of dissections in younger patients may

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TABLE

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latrogsnic Causes of Primary Dissecting Medial Hematomas of Coronary Artery

TABLE

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ARTERY -BULKLEY,

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Causes of Coronary Artery Occlusion and Acute Myocardial lschemia With or Without Sudden Death

1. 2. 3. 4. 5.

Trauma

to coronary

artery

by

catheter

during

angi-

ography Trauma to coronary artery by cannula during cardiopulmonary bypass Direct operative trauma during saphenous vein bypass grafting to coronary artery Coronary arterial hypertension from aortic prosthetic stenosis Closed or open cardiac massage

1.

Severe generalized coronary artherosclerosis (most common) Acute coronary artery thrombosis in vessels with old plaque Hemorrhage into old plaque (rare) Coronary artery embolism unassociated with significant artherosclerosis A. infective endocarditis B. Cardioversion C. Prosthetic valve D. Intracardiac thrombus Medial dissection of coronary artery A. Primary B. Secondary to aortic dissection

2. 3. 4.

5.

TABLE IV

Differences Between Primary Aorta and of Coronary Artery

Data Age Sex Hypertension Postpartum state Left ventricular hypertrophy Atherosclerotic plaques

showing how prosthetic aortic Figure 10. Diagram stenosis may cause coronary arterial hypertension. The systolic pressure gradient across a stenotic rigidframed prosthesis would occur above the level of the coronary ostia and transmit elevated systolic pressures to the coronary arteries which normally receive primarily only the diastolic pressure. Systolic hypertension may have contributed to isolated coronary artery dissections in two of our six patients (see Figure 6).

be due to their less frequent atherosclerosis. Although we have studied what may be the oldest patients (Cases 1 and 2) with coronary dissections, both had minimal atherosclerosis. Similarly, dissecting aneurysms of the aorta usually affect those with only mild, to at most moderate, atherosclerosis. Although primary coronary arterial dissection is usually fatal, this is not always the case. Thus, this condition should be suspected in patients with

(O-4+) Luminal narrowing External rupture Chronic dissection lntimal tear

Dissections -

Dissectmg Aneurysm of Aorta Older Men

of

Dissecting Aneurysm of Coronary Artery Younger Women 0 Frequent 0 o-1+

+ Rare + l-2+ 0 + Frequent Frequent

+ 0 Rare Rare

signs of acute myocardial ischemia who have the appropriate predisposing factors, whether “natural” or “iatrogenic.” Prompt diagnosis may allow operative intervention. ACKNOWLEDGMENT

We thank Ms. Sandra J. Lewis, Filippina Giacometti and Linda S. Docks for preparing the histologic sections.

REFERENCES 1. 2.

Pretty HC: Dissecting aneurysm of coronary artery in a woman aged 42: rupture. Br Med J 1: 667, 1931. Lovitt WV, Corzine WJ: Dissecting intramural hemorrhage of anterior descending branch of left coronary artery. Arch Pathol 54: 458, 1952.

3.

4.

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Boschetti A, Levine A: Cystic medionecrosis with dissetting aneurysm of coronary arteries. Arch Intern Med 102: 562, 1958. Schornagel HE: Dissecting aneurysm of a coronary artery. J Pathol 75: 464, 1958.

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6. 7. 8. 9. 10. 11.

12. 13.

14. 15.

16.

17.

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lglaver A, Schwarz J, Kroovand WH: Dissecting aneurysm of coronary artery producing myomalacia and death. Am Heart J 57: 630, 1959. Ahronheim JH, Wagman GF: Dissecting hemorrhage in media of coronary artery. Arch Pathol 67: 19, 1959. Ralston LS, Wasdahl WA: Isolated dissecting aneurysms. Arch Intern Med 105: 935, 1960. McKeown F: Dissecting aneurysm of the coronary artery in arachnodactyly. Br Heart J 22: 434, 1960. Wells AL: Dissecting aneurysm of coronary artery in the puerperium. J Pathol 79: 404, 1960. Burton JF, Zawadski ES: The coronary aneurysm. J Forensic Sci 7: 486, 1962. Brody GL, Burton JF, Zawadski ES, French AJ: Dissecting aneurysms of the coronary artery. N Engl J Med 273: 1,1965. Ashley PF: Dissecting aneurysm of the coronary artery. Delaware Med J 37: 6, 1965. Nalbandian RM, Chason JL: Intramural (intramedial) dissecting hematomas in normal or otherwise unremarkable coronary arteries. A “rare” cause of death. Am J Clin Patho143: 348, 1965. Kurrien F: Dissecting aneurysms of the coronary artery. Med Sci Law 5: 109,1965. Palomino SJ: Dissecting intramural hematoma of left coronary artery in the puerperium. Am J Clin Pathol 51: 119, 1968. Barrett DL: Isolated dissecting aneurysm of the coronary artery. A report of a case due to hypersensitivity angiitis. Ohio State Med J 65: 830, 1969. Kaufman G, Englebrecht WJ: Hemorrhagic intramural dissection of coronary artery with cystic medial ne-

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18. 19. 20. 21. 22.

23.

24.

25.

26. 27.

28.

crosis. Am J Cardio124: 409, 1969. Whitehead R, Dunnill MS: Primary dissecting aneurysms of coronary arteries. J Pathol99: 33, 1969. Benson PA: Dissecting aneurysms of right and left coronary arteries. J Forensic Sci 15: 65, 1970. Di Maio VJM, Di Maio DJ: Postpartum dissecting coronary aneurysm. NY State J Med 71: 767,197l. Roy JJ, Klein HZ: Dissecting aneurysm of the coronary artery. JAMA 218: 1047, 1971. Claudon DG, Claudon DB, Edwards JE: Primary dissecting aneurysm of coronary artery. A cause of acute myocardial infarction. Circulation 45: 259, 1972. Asuncion CM, Hyun J: Dissecting intramural hematoma of the coronary artery in pregnancy and the puerperium. Obstet Gynecol40: 202, 1972. Lopes de Foria J: Histopathological changes in the coronary arteries following shock or hypotension in man. Their relationship to thrombosis and atherogenesis. Pathol Microbial 26: 385, 1963. Heilbrunn A, Zimmerman JM: Coronary artery dissection: A complication of cannulation. J Thorac Cardiovast Surg 49: 767,1965. Ross RS, Gordon R: Coronary arteriography. Circulation 38 (suppl II): 67, 1968. Kitamura K, Gobel FL, Wang Y: Dissection of the left coronary artery complicating retrograde left heart catheterization. Chest 57: 587, 1970. Roberts WC, Buja LM: The frequency and significance of coronary arterial thrombi and other observations in fatal acute myocardial infarction. Am J Med 52: 425, 1972.

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