Evolution of salmonella aortitis towards the formation of abdominal aneurysm

An Unusual Case of Non-typhoidal Salmonella Bacteremia Causing Life-Threatening Aortitis

Non-typhoidal Salmonella typically presents with gastroenteritis. However, an invasive Salmonella infection, which may be typically seen in immunocompromised patients, has a propensity for aortic involvement, especially in patients with risk factors for atherosclerosis. Here we present a 60-year-old female with multiple comorbid conditions and currently on immunosuppressants for rheumatoid arthritis, who presented with nausea, vomiting, and fever of three weeks duration and was found to have Salmonella bacteremia. Blood cultures were positive for Salmonella enterica. Computed tomography (CT) abdomen with contrast was concerning for mycotic aortitis. The patient underwent endovascular repair of an aortic ulcer and was treated with a six-week course of ceftriaxone. Mycotic aneurysm is a rare but potentially fatal complication of invasive Salmonella infection. It occurs typically in older men with atherosclerotic risk factors. It mostly presents as fever, back pain, and/or abdominal pain. Our patient was a middle-aged female who presented with non-specific symptoms. CT angiogram is the diagnostic modality of choice and treatment may require surgical vascular repair and long-term antibiotics. A high level of suspicion is needed to diagnose Salmonella-related mycotic aneurysm/aortitis. Early diagnosis and treatment may improve the mortality.

Aortic Endograft Infection: Diagnosis and Management

Aortic endograft infection (AEI) is a rare but life-threatening complication of endovascular aneurysm repair (EVAR). The clinical features of AEI range from generalized weakness and mild fever to fatal aortic rupture or sepsis. The diagnosis of AEI usually depends on clinical manifestations, laboratory tests, and imaging studies. Management of Aortic Graft Infection Collaboration (MAGIC) criteria are often used to diagnose AEI. Surgical removal of the infected endograft, restoration of aortic blood flow, and antimicrobial therapy are the main components of AEI treatment. After removing an infected endograft, in situ aortic reconstruction is often performed instead of an extra-anatomic bypass. Various biological and prosthetic aortic grafts have been used in aortic reconstruction to avoid reinfection, rupture, or occlusion. Each type of graft has its own merits and disadvantages. In patients with an unacceptably high surgical risk and no evidence of an aortic fistula, conservative treatment can be an alternative. Treatment results are determined by bacterial virulence, patient status, including the presence of an aortic fistula, and hospital factors. Considering the severity of this condition, the best strategy is prevention. When encountering a patient with AEI, current practice emphasizes a multidisciplinary team approach to achieve an optimal outcome.

Imaging features of mycotic aortic aneurysms

Infectious aortitis (IA) is a rare and life-threatening cardiovascular disease. Early diagnosis and timely intervention are crucial for reducing mortality associated with mycotic aortic aneurysms (MAAs); however, early diagnosis is challenging due to the nonspecific symptoms. Some cases are diagnosed at an advanced stage or after developing complications, such as rupture or aortic fistula. Current state-of-the-art imaging modalities-including computed tomography (CT), magnetic resonance imaging (MRI), and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT-can detect infected aneurysms in clinically suspicious cases. MAA features on imaging include lobulated pseudoaneurysm, indistinct irregular arterial wall, perianeurysmal gas, perianeurysmal edema, perianeurysmal soft tissue mass, aneurysmal thrombosis, and high metabolic activity with increased uptake of FDG. Enlarged lymph nodes are often found adjacent to the aneurysm, while iliopsoas abscess (IPA), spondylitis, and aortic fistulas are commonly associated complications. After surgery or endovascular repair, radiological features-including ectopic gas, peri-graft fluid, thickening of adjacent bowel, pseudoaneurysm formed at the graft anastomosis, and increased uptake of FDG-may indicate an infection of aortic graft. This article provides an overview of the clinical and imaging features of MAAs. Thus, familiarity with the imaging appearances of MAAs may assist radiologists in the diagnosis and facilitation of timely treatment.

An Uncommon Cause of Deep Vein Thrombosis: Mycotic Aneurysm Secondary to Salmonella Arteritis

Mycotic aneurysm is an uncommon surgical emergency with high mortality. Endovascular infection due to salmonella is the commonest cause of intra-abdominal mycotic aneurysm. We report a rare presentation of mycotic aneurysm in a 78-year-old man who presented to the accident and emergency department with deep vein thrombosis due to compression of the iliac vein by a mycotic aneurysm arising from the internal iliac artery and an adjacent abscess. A comprehensive review of the aetiology, clinical presentation and management of mycotic aneurysm secondary to salmonella arteritis is presented.

Mycotic aneurysm in a turtle hunter: brief review and a case report

Salmonella-associated mycotic aneurysm is a rare, but dreaded, complication of salmonellosis. Immunocompromised and elderly populations are more susceptible to develop this extra-intestinal complication. Salmonella is spread via fecal–oral and vehicle-borne routes. Reptiles, especially small pet turtles, have been linked with an increased risk of Salmonella infection. Diagnosis of mycotic aneurysm is a challenge due to atypical presentations. Recently, widespread use of CT scan imaging to evaluate for unexplained abdominal pain and sepsis has led to early identification of mycotic aneurysms. Antibiotic therapy and surgical intervention are the cornerstones of management. Open surgery has been the gold standard of treatment but is associated with increased morbidity and mortality. A relatively new alternative to open surgery is endovascular aneurysm repair (EVAR). It is comparatively less invasive and is associated with reduced early morbidity and mortality in the setting of mycotic aneurysm. However, there is a risk of late infection. Here, we present a patient with Salmonella mycotic aneurysm initially treated conservatively with antibiotic therapy who later underwent successful interval EVAR with no complications to date. Also included is a brief review of Salmonella-associated mycotic aneurysms.

An immunosuppressed man with an aortic rupture secondary to Salmonella aortitis successfully treated with endovascular aortic repair

A 75-year-old immunosuppressed man presented with fever and central abdominal pain 3 weeks after having positive blood cultures for Salmonella enteritidis. A computed tomography scan demonstrated a contained perforation of a nonaneurysmal abdominal aorta. Salmonella aortitis was suspected, and given his recent history of coronary artery stent insertion, endovascular aortic repair was performed, with lifelong antibiotic therapy. At 6 months, there were no remaining clinical or radiological concerns for aortitis or aneurysmal development. This case highlights the high index of suspicion required for aortitis in immunosuppressed patients and verifies endovascular aortic repair, an appropriate alternative in patients with severe comorbidities.

Treatment of infected abdominal aortic aneurysm caused by Salmonella

BACKGROUND

We reviewed the outcomes of patients treated for nontyphoidal Salmonella-infected abdominal aortic aneurysm (AAA) treatment at a single center.

METHODS

This was a retrospective chart review of 26 patients with nontyphoidal Salmonella-infected AAA. Four patients underwent medical therapy alone, while 22 patients underwent surgical therapy. Revascularization method selection was dependent on preoperative antibiotic response in the surgical therapy group.

RESULTS

The in-hospital mortality rate for the surgical therapy group was 14%, while the rate for the medical therapy group was 100%. Overall survival for the surgical therapy group was 82%, while the reinfection rate was 9%. In the surgical therapy group, 2 patients had periaortic abscesses and underwent in situ prosthetic graft replacement; none developed graft-related complications or died in the hospital. Kaplan-Meier analysis and log-rank testing revealed no significant differences in graft-related complication and overall survival rates between in situ prosthetic graft group and extra-anatomic bypass group. Salmonella choleraesuis had a higher antimicrobial resistance rate than other isolates. The predictors of survival were clinical presentation of abdominal pain and receiving surgical therapy.

CONCLUSIONS

If patients with Salmonella-infected AAAs have good responses to preoperative antibiotic therapy, in situ prosthetic graft replacement is a viable revascularization method, even in the situation of periaortic abscess presentation formation.

Infectious aortitis caused by Salmonella Dublin followed by aneurysmal dilatation of the abdominal aorta

A 67-year-old woman was admitted for severe abdominal pain (stomach ache). Computed tomography (CT) revealed gas along the abdominal aortic wall. A blood culture was positive for Salmonella dublin, a gram-negative bacillus that is rare in humans. Treatment with an antibiotic improved the inflammatory signs; however, on the 11th hospital day, the patient complained of sudden severe abdominal pain. Enhanced CT revealed a pseudoaneurysm surrounded by a periaortic abscess. The infected aortic wall, including the aneurysm, was resected and an extra-anatomic bypass was constructed between the axillary artery and the external iliac arteries. The patient recovered fully and her course has been uneventful for the past two years since her discharge.

Endovascular repair of Salmonella-infected abdominal aortic aneurysms: a word of caution

Over the last several years, treatment modalities have changed for infected aortic aneurysms. Surgical treatment has undergone a paradigm shift from débridement and extra-anatomic bypass to direct reconstruction to, most recently, endovascular repair. Although many reports of endovascular repair of such aneurysms are favorable, the following two cases highlight some of the concerns with endografts in an infected field. Specifically, we urge caution when considering endovascular repair of Salmonella-infected arterial pathologies.

The spectrum of cardiovascular infections due to Salmonella enterica: a review of clinical features and factors determining outcome

Cardiovascular infections due to Salmonella enterica are infrequently reported, so their clinical features, prognosis, and optimal treatment are not completely known. Mortality associated with aortitis and endocarditis caused by nontyphoidal Salmonella remains exceedingly high. In this review of cases of cardiovascular infections due to Salmonella enterica studied in 2 hospitals in Madrid, we tried to assess the clinical manifestations and the procedures leading to diagnosis in addition to treatment and outcome. To complete the spectrum of infections related to cardiovascular surgery, cases of postoperative mediastinitis, pericarditis, and infections associated with cardiac devices were also included.Twenty-three patients were reviewed: 11 had mycotic aneurysms; 7 had endocarditis; 2 had device-related infections; and 3 had pericarditis, mediastinitis, and infection of an arteriovenous fistula, respectively. The risk of endovascular infection in patients older than 60 years with bacteremia due to nontyphoidal Salmonella was 23%. Most patients with aortitis had risk factors for atherosclerosis, and 6 had preexisting atherosclerotic aortic aneurysms. All except 1 patient with endocarditis had underlying cardiac disorders. Acquired immunodeficiency disease (AIDS) was a major risk factor for salmonella bacteremia in 1 patient with aortitis and 1 with endocarditis. Fever, unremitting sepsis, "breakthrough" and relapsing bacteremia were the most common clinical findings. In addition, abdominal or thoracic pain and cardiac failure and pericarditis were common features in patients with aortitis and endocarditis respectively. Computed tomography (CT) scan, arteriography, and echocardiography were the main diagnostic tools. Mortality associated with mycotic aneurysms and endocarditis due to S. enterica was 45% and 28%, respectively. Thoracic aneurysms, rupture, and shock at the time of diagnosis were associated with increased mortality in patients with aortitis. In situ bypass grafting was successfully performed in most cases. After surgery, antimicrobial therapy was continued for 4-9 weeks. No relapses were observed after a mean follow-up of 64 months. Antimicrobial therapy alone or combined with valve replacement or excision of a ventricular aneurysm was successful treatment for most patients with salmonella endocarditis. Combined medical and surgical treatment was required for patients with mediastinitis and pericarditis, and patients with device-related infections needed removal of the complete device. Diagnosis of aortitis due to nontyphoidal Salmonella should be established as early as possible to reduce mortality. Patients older than 60 years who have positive blood cultures for Salmonella along with fever and back, abdominal, or chest pain should have an extensive workup for infective aortitis. Immediate bactericidal antimicrobial therapy should be started and a CT scan should be performed on an emergency basis. If a mycotic aneurysm is found, surgical resection should follow as soon as possible. Resection of the aneurysm with in situ bypass grafting is the procedure of choice. Postoperative antimicrobial therapy for 6-8 weeks seems enough to avoid relapses. Optimal treatment of patients with endocarditis occurring on ventricular aneurysms must include resection of the aneurysmal sac. Salmonella endocarditis can be successfully treated with antimicrobials alone. Valve replacement should be reserved for patients with cardiac failure or persisting sepsis, and for those who relapse after discontinuation of antimicrobial therapy.

Infected abdominal aortic aneurysm presenting with sudden appearance: diagnostic importance of serial computed tomography

The case of an 86-year-old man with an infected abdominal aortic aneurysm (AAA) that developed suddenly over 3 weeks is presented here. Previous reports on the diagnosis of infected AAA have focused mainly on the findings of single computed tomography (CT). These include the presence of a saccular aneurysm with an irregular lumen, perianeurysmal fluid, gas and/or hematoma, osteomyelitis in adjacent vertebral bodies, disruption of intimal calcification, and obscuring of the aortic wall. Our case report presents a useful diagnostic technique for the diagnosis of infected AAA, emphasizing the importance of serial CT for suspected cases, even if the initial scan does not demonstrate the findings listed above.