Rare Case of Mycotic Aneurysm of Brachial Artery in patient with Aplastic Anemia

Brachial artery aneurysm is relatively rare when compared to lower extremity aneurysm with an incidence of 3-4%. The clinical presentation of a pseudo-aneurysm is variable. It usually presents as a slow-developing painless, pulsatile and asymptomatic mass and may take days to months, even years to manifest clinically. Occasionally, complications such as haemorrhage or thrombosis occur causing the mass to grow rapidly and become painful producing vascular insufficiency with ischemic changes in the anatomical regions supplied by it.

The team reported about a 19-year old male patient with severe aplastic anemia (SAA), treated with the combination of anti-thymocyte globulin (ATG) and cyclosporine. He was admitted to the hospital with complaints of lower backache and fever for 10 days and presented with the symptoms of fever, pallor with tenderness and spasm over the lumbar paraspinal area bilaterally. Blood culture confirmed the presence of Methicillin resistant Staphylococcus aureus which was sensitive to clindamycin and vancomycin. Upon analysing the Magnetic resonance imaging (MRI) reports, doctors identified an abscess near the left sacroiliac joint with mild joint effusion. The patient was then treated with parental antibiotics and received a blood transfusion for the treatment of anemia. After four weeks, the infection resolved which was confirmed by repeated blood culture.

One month later, he was presented with a swelling on the medial side of the left arm which was progressively increasing in size with no functional impairment of the limb. Upon physical examination, the doctors identified an ovoid swelling measuring 5x3 cm, non-tender, pulsatile, non-expansible, non- fluctuant, compressible but non-reducible mass on the medial aspect of left arm, approximately 15 cm above the medial epicondyle of the humerus. Using ultrasonography (USG) the team identified a pseudoaneurysm, arising from left proximal brachial artery measuring 5 x 3 x 2 cm in dimension with peripheral thrombus formation. The patient was then diagnosed with mycotic pseudo-aneurysm of the left proximal brachial artery which was confirmed by CT findings. The team performed an embolisation, considering low platelet count.

Three months later, the patient was again admitted to the hospital with a pain in the left forearm and fingers and wasting of forearm and hand muscles. On examination, the doctors found a hard, non-tender and non-compressible mass in the proximal arm. Physical examination further revealed a decreased temperature of the skin in forearm and palms with wasting of flexor muscles of the forearm and palmar muscles of the hand. Using USG, the team identified a calcified thrombus in the region of brachial artery pseudo-aneurysm sac with decreased distal blood flow. The team performed an arterial catheterization and placed a stent in the brachial artery to ensure adequate distal blood flow. The patient then showed clinical improvement with amelioration of his symptoms and signs of vascular insufficiency. Later the team performed a plain radiograph of the left upper limb with chest which showed a calcified thrombus with the stent-in situ.

The treatment of brachial artery aneurysm depends on the location, size, pathogenesis, and accessibility of the pseudo-aneurysm. Mycotic brachial artery aneurysm has been treated surgically by proximal ligation and resection of the aneurysm. Arterial reconstruction has been done either by the end to end anastomosis, vein graft interposition or vein graft. Endovascular methods (endovascular stent-graft implantation, embolisation of sac, embolisation of distal and proximal arterial segments) have become more popular because they are less invasive and associated with lower complication rates.

The authors mentioned, "In our patient, we preferred endovascular intervention due to presence of pancytopenia corollary to aplastic anemia and reduce the risk of complications associated with surgery".

For further information:

https://www.japi.org/x274a4b4/mycotic-aneurysm-of-brachial-artery-in-case-of-aplastic-anemia