KD Pathology

Heart and lung block from the post-mortem examination of a 3 month-old female infant who died on Day 21 of KD. Note the beaded appearance of the coronary arteries (arrow). This is the external appearance of the coronary artery aneurysm seen on transverse section in picture below.
Transverse section of coronary artery aneurysm from autopsy described in above. This transverse section of the right coronary artery demonstrates transmural infiltration by lymphocytes and neutrophils. The inflammatory infiltrate is associated with disruption of the vessel's muscularis and intima.
Higher magnification of section in box. Destruction of the vessel wall's structural integrity predisposes to aneurysm formation. Concomitant destruction of the intima has lead to early thrombus formation (arrow). Coronary artery thrombosis associated with these aneurysms is the most common cause of death in patients with KD.
Transverse section of the axillary artery from a 4 month-old female 6 weeks after onset of acute KD. Acute inflammatory lesions of the vessel wall heal by medial fibrosis and intimal thickening. These precesses may lead to luminal narrowing or stenosis as seen in this artery.
Echocardiogram of a 2 month-old male infant with 6 mm aneurysms of the left coronary artery. Fortunately, most pediatric patients can be evaluated initially and followed by non-invasive imaging of the coronary arteries. Echocardiography is a very sensitive and specific method to detect coronary artery dilatation and aneurysms. The technique is less sensitive for the detection of stenotic lesions that may occur as part of the healing process in large aneurysms. Arrows indicate two regions of focal dilatation in the left coronary artery.
Selective injection of the left coronary artery demonstrating two large, saccular aneurysms in the proximal left anterior descending and circumflex coronary arteries. This 12 year-old male had chest pain and ECG findings consistent with acute ischemia 8 months following KD. Coronary artery aneurysms may develop in 15-25% of untreated KD patients as a result of the severe inflammatory destruction and weakening of the vessel wall. Thrombus formation in these aneurysms is the most serious complication of KD. Stenosis at the outlet of the aneurysm is a risk factor for thrombus formation.
Selective injection of the left coronary artery demonstrating a single, saccular aneurysm at the bifurcation of the circumflex and left anterior descending arteries. Angiography is recommended for all patients who have aneurysms detected by echocardiogram in order to more precisely define the anatomy of the lesions and to detect stenosis associated with the outflow tract of the aneurysm.
Selective injection of the left coronary artery in a 42 year-old male who suffered a massive anterior myocardial infarction when thrombus formed and occluded the left anterior descending artery. The patient had a history of "atypical scarlet fever" at age 5 yrs., ten years before Dr. Kawasaki described his first 50 cases in Japanese.

For more information, contact Dr. Jane Burns at 858-246-0155 or email: jcburns@ucsd.edu