Surgical Treatment of an Infected Popliteal Artery Aneurysm 12 Years after Aneurysm Exclusion and Bypass

Citrobacter koseri Surgical Site Infection after Femoropopliteal Vein Bypass for Popliteal Artery Aneurysm Treated with a Graft Preserving Strategy

Background: A 69-year-old man underwent ligation and evacuation of a popliteal artery aneurysm with a femoral-to-popliteal vein bypass. He had a history of Citrobacter koseri prostatitis two months prior to the surgery. One month postoperatively, he presented with extremity swelling, redness, and fluid collections around the graft. Methods: A graft preserving strategy was adopted. The patient underwent operative drainage, washing, and received long-term antibiotic therapy. Fluid culture grew Citrobacter koseri, previously not reported as cause of surgical site infection with infrainguinal graft involvement. Results: The infection was treated successfully, and the patient is remains symptom free 18 months post-operatively. Conclusions: This case highlights the importance of considering culturing the aneurysm content in the presence of infectious history.

Serratia liquefaciens Infection of a Previously Excluded Popliteal Artery Aneurysm

Introduction

Popliteal artery aneurysms (PAAs) are rare in the general population, but they account for nearly 70% of peripheral arterial aneurysms. There are several possible surgical approaches including exclusion of the aneurysm and bypass grafting, or endoaneurysmorrhaphy and interposition of a prosthetic conduit. The outcomes following the first approach are favorable, but persistent blood flow in the aneurysm sac has been documented in up to one third of patients in the early post-operative setting. Complications from incompletely excluded aneurysms include aneurysm enlargement, local compression symptoms, and sac rupture. Notably infection of a previously excluded and bypassed PAA is rare. This is the third reported case of PAA infection after exclusion and bypass grafting and the first due to Serratia liquefaciens.

Methods

Relevant medical data were collected from the hospital database.

Results

This case report describes a 54 year old male patient, diagnosed with acute limb ischaemia due to a thrombosed PAA, submitted to emergency surgery with exclusion and venous bypass. A below the knee amputation was necessary 3 months later. Patient follow-up was lost until 7 years following surgical repair, when he was diagnosed with aneurysm sac infection with skin fistulisation. He had recently been diagnosed with alcoholic hepatic cirrhosis Child–Pugh Class B. The patient was successfully treated by aneurysm resection, soft tissue debridement and systemic antibiotics.

Conclusion

PAA infection is a rare complication after exclusion and bypass procedures but should be considered in any patient with evidence of local or systemic infection. When a PAA infection is diagnosed, aneurysmectomy, local debridement, and intravenous antibiotic therapy are recommended. The “gold standard” method of PAA repair remains controversial. PAA excision or endoaneurysmorrhaphy avoids complications from incompletely excluded aneurysms, but is associated with a high risk of neurological damage.

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Popliteal artery aneurysms (PAAs) are the most common cause of non-traumatic leg amputation.

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Potential complications from PAA exclusion are aneurysm enlargement, local compression symptoms, sac rupture, and infection.

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Infection of a previously excluded and bypassed popliteal artery aneurysm is exceedingly rare.

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This is the third case of excluded aneurysm infection, and the first by the Serrate genus.