This case report documents a true aneurysm of the ulnar artery in the palm in an HIV-positive patient. The patient, a 25 year old male, presented with a localized area of swelling in the palm in the region of Guyon’s canal with no known history of trauma or drug injection. The patient was known to be HIV-positive from transfusion of blood products for treatment of his hemophilia. Work-up included radiography, which was negative, and ultrasonography. Ultrasound documented a 2.3 x 0.37 cm aneurysmal dilation of the ulnar artery. The patient had slight paresthesias in the distal ulnar nerve territory, and electrodiagnostic testing confirmed a mild motor and sensory neuropathy in the area of Guyon’s canal. Distal circulation remained intact. The authors report that the management at the time of initial presentation was determined, in part, by the patient’s HIV status. They elected not to treat the lesion. One year later, the patient suffered local blunt trauma in a fall and experienced an increase in the size of the lesion with exacerbation of the ulnar neuropathy. Surgery was performed and a large ruptured aneurysm was found in the ulnar artery distal to Guyon’s canal. There was noted to be visible compression of the ulnar nerve in the area of the aneurysm. Treatment consisted of ligation of the artery with resection of the aneurysm and neurolysis of the ulnar nerve. Distal digital circulation did not mandate reconstruction of the artery. Immediate improvement in sensation was noted and the patient had no further symptoms during 12 months of follow-up. Histology confirmed a true (not a pseudo-) aneurysm, with involvement of all laminar layers of the artery.
HIV-related aneurysms have been reported sporadically elsewhere. The pathogenesis is questionable, and the authors outline the existing hypotheses. Coincidental occurrence, leukocytic infiltration in the immunocompromised host, invasion of the arterial wall by HIV virus, and infectious infiltration of the arterial wall by an opportunistic pathogen have all been postulated. Indeed, true aneurysms are rare in the hand, with the majority of arterial dilations resulting from trauma and defined histologically as pseudoaneurysms. Thus, some etiologic role of the HIV infection in these aneurysms does seem more likely. With the increasing effectiveness of suppressive therapies used to treat HIV, and the resultant increasing longevity and prevalence of HIV-infected patients in every population, surgical management of these types of cases may become more common. The complications of distal embolization or thrombosis, proximal occlusion, and severe motor neuropathy are ominous and warrant treatment in all but the most imminently terminal patients. The suspicion of HIV-related aneurysm of the ulnar artery should be added to the usual traumatically-induced pseudoaneurysms already in the differential diagnosis of expanding lesions within Guyon’s canal and localized ulnar nerve compression.