Clostridium septicum-infected aortic aneurysm or graft is a deadly diagnosis

BACKGROUND

Clostridium septicum is an anaerobic, motile, spore-forming, toxin-producing gram-positive bacillus that can lead to rapidly progressive gas gangrene due to the release of alpha toxin. Aortic aneurysm secondary to C. septicum infection is a rare condition with 60 cases reported in the literature; however, we have recently treated several patients with the condition in our large tertiary care and aortic center.

METHODS

Blood and tissue culture results collected between January 2005 and January 2018 and maintained in the microbiology laboratory database at the Cleveland Clinic were reviewed to identify those with C. septicum reported. Each was reviewed to determine radiographic or histopathologic correlation with aortic disease.

RESULTS

Seven cases of C. septicum aortitis were reviewed. Underlying malignant disease was found in four cases and a history of remote malignant disease in one case. The most common location for infection was the infrarenal abdominal aorta. Vascular surgery had previously been performed in three of the cases. Five of the seven patients underwent operative repair. All patients were treated with β-lactam antibiotics. The two patients who did not undergo an operation died, which is consistent with the 100% mortality described in the literature. Of the five patients who underwent an operation, there was only one documented survivor and one was lost to follow-up.

CONCLUSIONS

In the largest reported case series, only a small percentage of patients with C. septicum-infected aortic aneurysms survived >1 year. In the patients described, those who did not receive an operation had 100% mortality. Earlier recognition and prompt operation with appropriate antimicrobial therapy are needed to improve the outcome of patients diagnosed with this rare infection.

Presence of periaortic gas in Clostridium septicum-infected aortic aneurysm aids in early diagnosis: a case report and systematic review of the literature

BACKGROUND

Clostridium septicum-infected aortic aneurysm is a fatal and rare disease. We present a fatal case of C. septicum-infected aortic aneurysm and a pertinent literature review with treatment suggestions for reducing mortality rates.

CASE PRESENTATION

A 58-year-old Japanese man with an unremarkable medical history presented with a 3-day history of mild weakness in both legs, and experienced paraplegia and paresthesia a day before admission. Upon recognition of signs of an abdominal aortic aneurysm and paraplegia, we suspected an occluded Adamkiewicz artery and performed a contrast-enhanced computed tomography scan, which revealed an aortic aneurysm with periaortic gas extending from his chest to his abdomen and both kidneys. Antibiotics were initiated followed by emergency surgery for source control of the infection. However, owing to his poor condition and septic shock, aortic repair was not possible. We performed bilateral nephrectomy as a possible source control, after which we initiated mechanical ventilation, continuous hemodialysis, and hemoperfusion. A culture of the samples taken from the infected region and four consecutive blood cultures yielded C. septicum. His condition gradually improved postoperatively; however, on postoperative day 10, massive hemorrhage due to aortic rupture resulted in his death.

CONCLUSIONS

In this patient, C. septicum was thought to have entered his blood through a gastrointestinal tumor, infected the aorta, and spread to his kidneys. However, we were uncertain whether there was an associated malignancy. A literature review of C. septicum-related aneurysms revealed the following: 6-month mortality, 79.5%; periaortic gas present in 92.6% of cases; no standard operative procedure and no guidelines for antimicrobial administration established; and C. septicum was associated with cancer in 82.5% of cases. Thus, we advocate for early diagnosis via the identification of periaortic gas, as an aortic aneurysm progresses rapidly. To reduce the risk of reinfection as well as infection of other sites, there is the need for concurrent surgical management of the aneurysm and any associated malignancy. We recommend debridement of the infectious focus and in situ vascular graft with omental coverage. Postoperatively, orally administered antibiotics must be continued indefinitely (chronic suppression therapy). We believe that these treatments will decrease mortality due to C. septicum-infected aortic aneurysms.

How To Diagnose and Manage Infected Endografts after Endovascular Aneurysm Repair

The prevalence of endograft infections (EI) after endovascular abdominal aortic aneurysm repair is below 1%. With the growing number of patients with aortic endografts and the aging population, the number of patients with EI might also increase. The diagnosis is based on an association of clinical symptoms, imaging, and microbial cultures. Angio-computed tomography is currently the gold-standard technique for diagnosis. Low-grade infection sometimes requires nuclear medicine imaging to make a correct diagnosis. There is no good evidence to guide management so far. In the case of active gastrointestinal bleeding, pseudoaneurysm, or extensive perigraft purulence involving adjacent organs, an invasive treatment should always be attempted. In the other cases (the majority), when there is not an immediate danger to the patient's life, a conservative management is started with a proper antimicrobial therapy. Any infectious cavity can be percutaneously drained. Management depends on the patient's condition and a tailored approach should always be offered. In the case of a patient who is young, has a good life expectancy, or in whom there is absence of significant comorbidities, a surgical attempt can be proposed. Surgical techniques favor, in terms of mortality, patency, and reinfection rate, the in situ reconstruction. Choice of technique relies on the center and the operator's experience. Long-term antibiotic therapy is always required in all cases, with close monitoring of the C-reactive protein.