Treatment of Critical Hand Ischemia Due to Mycotic Aneurysm of Radial and Ulnar Arteries: A Case Report

Introduction

Mycotic aneurysms are rare presentations, resulting from arterial injury combined with microbial seeding of a vessel wall, leading to destruction of the media and elastic lamina.^1,2 Staphylococcus aureus is the most common pathogen, followed by Salmonella and Pseudomonas species. ¹ Infection-induced inflammation activates matrix metalloproteinases, weakening the vessel wall and predisposing to rupture, thrombosis, or distal ischemia.^2,3 There are no specific diagnostic criteria for mycotic aneurysms. A thorough evaluation involving blood tests and imaging can help characterize the condition and guide management.^1,4 Prolonged antibiotic therapy is needed, with definitive management requiring surgery to prevent complications such as aneurysmal rupture, sepsis, thrombosis, and distal limb ischemia.^2,5

Case Report

Initial Operation–Adventitial Stripping of the Radial and Ulnar Arteries

In the main operation room, exploration revealed heavily calcified radial and ulnar arteries. Both vessels underwent adventitial stripping over 5 cm (Figure 1), with small finger debridement. Postoperatively, pain resolved completely and doppler signals were present in both arteries.

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Figure 1.

Adventitial stripping of the radial and ulnar arteries.

Unfortunately, five weeks later, the patient suffered a cardiac arrest that required cardiopulmonary resuscitation and insertion of an arterial line into their right radial artery at the wrist. Two months later, necrosis of the small and index fingertips developed. Angiography revealed poor distal radial and ulnar flow but a patent deep palmar arch, prompting the decision for bypass reconstruction using a vein graft.

Second Operation (Six Months Following)

During re-exploration, multiple fluid-filled sacs encased the ulnar artery (Figure 2). Rupture of these encapsulated structures released purulent discharge, with cultures positive for Streptococcus species (Figure 3). Histopathologic findings showed the ulnar artery was thickened and hemorrhagic over a 7 cm segment, with above 90% luminal occlusion. There was destruction of the tunica media and internal elastic lamina, dense neutrophilic infiltration, and intraluminal bacterial colonies, findings consistent with a mycotic aneurysm (Figure 4).

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Figure 2.

Ulnar artery encapsulated structures.

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Figure 3.

Encapsulated structures from ulnar artery.

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Figure 4.

Ulnar artery mycotic aneurysm.

The diseased arterial segments were resected, and interpositional vein grafts from the foot were anastomosed to the superficial and deep palmar arches. The patient recovered uneventfully and was discharged several days later. At two-month follow-up, perfusion was restored to all digits with full resolution of pain.

Discussion

Mycotic aneurysms are relatively uncommon, accounting for 0·7%–3% of all aortic aneurysms and rarely occur in the upper extremities. ⁶ The combination of arterial trauma and hematogenous bacterial seeding played a central role in the subsequent formation of the mycotic aneurysm.

This case highlights the complexity of diagnosis and treatment, being noteworthy due to the placement of an arterial line following the initial procedure, combined with chronic foot infections that likely precipitated bacterial seeding of previously injured vessels. Clinical suspicion and imaging were crucial to operative planning, but the definitive diagnosis was only confirmed intraoperatively. Prompt surgical debridement and bypass reconstruction achieved source control and limb salvage.

Conclusion

Upper extremity mycotic aneurysms are rare but serious infections requiring timely recognition and surgical management. Patient comorbidity can significantly contribute to the development of mycotic aneurysms and subsequently exacerbate vascular compromise requiring reconstruction. Surgical intervention, including resection and bypass grafting, was required to successfully restore perfusion and allow limb salvage.