A 10-month-old boy was referred to our hospital because swellings were found in his bilateral axillae. Four months prior to referral, the infant had recurrent fever, followed by bilateral conjunctival congestion and a maculopapular rash on his limbs and trunk. Laboratory tests showed elevated leucocytes and C reactive protein. His fever persisted after antibiotic therapy. On the 10th day of fever, echocardiographic examination at a local hospital showed dilation of bilateral coronary arteries (there were no documented diameters for each coronary artery). He was then diagnosed with Kawasaki disease (KD) and administrated intravenous immunoglobulin (IVIG, 2g/kg/dose) and aspirin (40mg/kg/d q8h) immediately. After finishing the IVIG infusion, his fever subsided and clinical symptoms and laboratory test improved uneventfully. Three days later, he was discharged with low dose aspirin and dipyridamole. The infant was followed up at the local hospital due to restrictions relating to the COVID-19 pandemic, and he remained afebrile and echocardiography showed no obvious changes. One month prior to referral, his parents incidentally felt swellings in his bilateral axillae, but they did not think much of it. Three days before presentation to our hospital, the infant had an ultrasound done at the local hospital his regular follow-up, which found suspected axillary artery aneurysms or pseudoaneurysms. He was then immediately referred to our hospital for further evaluation.
On admission, a pulsatile swelling in the right axilla and a non-pulsatile swelling in the left axilla were palpated. The left brachial and radial pulses were impalpable. The skin temperature of the left upper limb was lower than that of the right one, and the left palm was pale. The movement of left upper limb was less active than that of the right. The pulses, skin temperature, and color of right upper limb and both lower extremities were all normal.
After admission, ultrasound showed a giant right axillary artery aneurysm (AAA) 26*12.7*19.5mm in size with a wall thickness 1.2mm. The flow inside the aneurysm was patent with no stenosis and the diameters of the distal and proximal adjacent arteries were about 2.3-3.0mm (Figs. 1a & b). In left axilla, a large heterogeneous mass (41.4*11.7*15.8mm) without blood flow was detected which suggested complete occlusion (Figs. 1c & d).
No abnormalities were found on echocardiography except for bilateral multiple giant coronary artery aneurysms (CAAs) involving the left anterior descending artery (LAD) and right coronary artery (RCA). The internal diameters of the aneurysm in the LAD, the proximal RCA, and mid RCA were 7.48mm (z score = + 18.65), 9.0mm (z score = + 20.76) and 5.09mm (z score = + 10.64) respectively. Investigations to rule out myocardial ischemia including 12-lead electrocardiography, 24-hour Holter monitor, 2-dimention and tissue Doppler echocardiography, and ATP stressed nuclide myocardial perfusion imaging were all normal.
Angiography was done for the patient. Coronary angiography showed bilateral multiple giant CAA, including a 6.0*8.5mm CAA at the bifurcation of the LAD and circumflex branch (Fig. 2a) and several beaded CAAs in RCA from proximal to the origin of the posterior descending coronary artery (the diameters of aneurysms were 9.0mm, 7.6m m, 6.8mm, and 5.2mm, respectively) (Fig. 2b). An incomplete thrombus could be seen in the third aneurysm of the RCA (Fig. 2b, arrows). Fortunately, the flow of the LCA and RCA was patent with no stenoses or occlusions. Left and right subclavian arteriography showed bilateral giant AAAs. The size of the right AAA was 15.5*25.0mm with no thrombus in the aneurysm (Fig. 2c). The blood flow throughout the right upper limb was normal. The size of left AAA was 16.5*45.0mm, with complete embolism inside the aneurysm. There were some fine collateral vessels connecting to the distal brachial artery, and the blood flow into the distal left upper limb was slow and sparse (Fig. 2d). No abnormalities of other peripheral arteries were found.
After completing investigations and consulting with the vascular surgical team, we administrated intravenous prostaglandin for this baby to accelerate angiogenesis of the collateral vessels instead of surgical repair of the occluded aneurysm. At the same time, oral aspirin 5mg/kg per day and low molecular weight heparin (150u/kg/ dose q12h) were given to prevent thrombosis in the right AAA and CAAs. Metoprolol was used to reduce myocardial oxygen demand because of the giant CAAs. After ten days of treatment, the patient’s skin temperature and movement of left upper limb had improved, and a weak pulse of left brachial artery could be palpable. Low molecular weight heparin was then switched to warfarin, with international normalized ratio (INR) monitored to be near 2.5.
Three months after discharge, the patient was followed up. During his stay at home, he was asymptomatic and grew well. Physical examination showed that skin temperature, movement, and left upper limb pulses further improved to a similar level to that of the right side. CT angiography confirmed that the blood flow of the brachial artery at the distal part of the embolized left axillary artery was significantly increased (Fig. 2e). Repeat echocardiography showed the coronary arteries remained the same as before; electrocardiography was normal.