Infected aortic aneurysms: CT features

Endovascular Coil Embolization of an Enlarging Gastroduodenal Artery Aneurysm

Gastroduodenal artery aneurysms are a rare type of visceral aneurysm that can lead to rupture and death. We present a 75-year-old male with history of hypertension, diabetes, and hyperlipidemia with an incidental finding of a 3.2 × 3.7 cm gastroduodenal aneurysm found on abdominal computed tomography angiography (CTA). After refusing surgical intervention, he was seen two years later and presented with an enlarged gastroduodenal aneurysm, now 5.0 × 5.1 cm, visible on a repeat abdominal CTA. Upon his continued refusal for an open surgery, we elected for endovascular repair of this GDA aneurysm via coil embolization.

Mycotic Aneurysm: A Rare Etiology of a Common Presentation

Mycotic aneurysms are a rare complication of systemic infections, where the arterial vessel wall becomes dilated secondary to bacterial, fungal, or viral infection. The incidence of mycotic aneurysms is rare but carries a significant mortality risk. Patients with mycotic aneurysms can have wide-ranging clinical presentations depending on the site of the aneurysm. Our case discusses one of the most encountered emergency department (ED) presentations, i.e., nausea and vomiting, as a presenting symptom of a patient found to have a mycotic aneurysm.

A 56-year-old patient with a history of HIV, unknown viral load or CD4 count, and admitted IV drug use presented to the ED by ambulance with multiple episodes of nausea and non-bloody vomiting. The patient was noted to be afebrile but met systemic inflammatory response syndrome (SIRS) criteria, necessitating a further workup. CT of the abdomen and pelvis was notable for a saccular aneurysm involving the infrarenal aorta with a large thrombosed component.

This case highlights the importance of early consideration of infected (mycotic) aneurysms in the appropriate patient setting, as delayed diagnosis increases the risk of rupture and death. In a case of non-specific nausea and vomiting, it is not unreasonable to assume this presentation could be attributed to a more benign process, delaying the diagnosis. It may, therefore, be prudent for emergency service providers to add mycotic aneurysms to the differential diagnosis for patients with appropriate risk factors, as presentations of mycotic aneurysms vary greatly.

Features of infective native aortic aneurysms on computed tomography

Background

Infective native aortic aneurysm (INAA) is a rare clinical diagnosis. The purpose of this study was to describe the CT findings of INAAs in detail.

Methods

This was a retrospective single-center study of INAA patients at a major referral hospital between 2005 and 2020. All images were reviewed according to a protocol consisting of aneurysm features, periaortic findings, and associated surrounding structures.

Results

One hundred and fourteen patients (mean age, 66 years [standard deviation, 11 years]; 91 men) with 132 aneurysms were included. The most common locations were infrarenal (50.8%), aortoiliac (15.2%), and juxtarenal (12.9%). The mean transaxial diameter was 6.2 cm. Most INAAs were saccular (87.9%) and multilobulated (91.7%). Calcified aortic plaque was present in 93.2% and within the aneurysm in 51.5%. INAA instability was classified as contained rupture (27.3%), impending rupture (26.5%), and free rupture (3.8%). Rapid expansion was demonstrated in 13 of 14 (92.9%) aneurysms with sequential CT studies. Periaortic inflammation was demonstrated as periaortic enhancement (94.7%), fat stranding (93.9%), soft-tissue mass (92.4%), and lymphadenopathy (62.1%). Surrounding involvement included psoas muscle (17.8%), spondylitis (11.4%), and perinephric region (2.8%). Twelve patients demonstrated thoracic and abdominal INAA complications: fistulas to the esophagus (20%), bronchus (16%), bowel (1.9%), and inferior vena cava (IVC) (0.9%).

Conclusion

The most common CT features of INAA were saccular aneurysm, multilobulation, and calcified plaques. The most frequent periaortic findings were enhancement, fat stranding, and soft-tissue mass. Surrounding involvement, including psoas muscle, IVC, gastrointestinal tract, and bronchi, was infrequent but may develop as critical INAA complications.

Long-Term Outcomes of Surgical Treatment by In Situ Graft Reconstruction for Infected Abdominal Aortic Aneurysm

Objectives: The optimal surgical management for primary infected abdominal aortic aneurysm (IAAA) is controversial. Here, we report the early and long-term results of surgical treatments with the resection of the IAAA and in situ graft reconstruction with pedicled omental coverage that was performed at out hospital.

Methods: Between 2010 and 2017, 27 consecutive patients (26 males, 1 female, median age 69 years) with IAAA were surgically treated with the resection of the IAAA, in situ graft reconstruction and covered with a pedicled omental flap. Perioperative and long-term outcomes were reviewed retrospectively by medical records.

Results: Clinical manifestations, including pyrexia, fever and abdominal pain, were observed during the treatment of the patients. Aneurysm excision and in situ graft reconstruction with omental coverage were performed for all cases. In 13 cases (48.1%), tissue culture was positive. The antibiotic was administered intravenously for 9 to 47 days (median 18 days) postoperatively, and after confirming the reduction of the inflammatory response, it was administered as oral agents for 24 to 443 days (median 169 days).There was no perioperative death or re-infection. Perioperative complications were found in 8 cases (29.6%) of minor spinal cord infarction, ileus, chylous ascites, and cholangitis due to choledochlithiasis. During the observation period of median 1,147 days, there was no recurrence of infection, graft infection, or disease-related death. There were six deaths due to other diseases. And the overall survival rate was 76.2%.

Conclusion: According to our study, the long-term outcomes of surgical treatment with in situ graft reconstruction for IAAA were considered satisfactory. (This is a translation of Jpn J Vasc Surg 2019; 28: 35–40.)

Abdominal aortic aneurysm: pictorial review of common appearances and complications

Abdominal aortic aneurysms (AAAs) are defined as focal dilatations of the abdominal aorta that are 50% greater than the proximal normal segment or when it is more than 3 cm in maximum diameter. The early diagnosis and treatment is very important to prevent catastrophic complications. Due to its ability to assess the peri-aortic soft tissue and the exact extension of aneurysm, as well as its excellent vascular opacification and multiplanar reconstruction capabilities, computed tomography angiography (CTA) has become an integral part of the evaluation of AAA and has virtually replaced conventional angiography for the evaluation of AAA. Knowledge of the characteristic imaging features of AAA is essential for the prompt diagnosis of life-threatening complications. In this pictorial essay, we will discuss the CTA findings in AAA and its complications including rupture, infection, aorto-enteric fistula and aorto-caval fistula.

Cross-sectional imaging of aortic infections

Aortic infections are uncommon clinical entities, but are associated with high rates of morbidity and mortality. In this review, we focus on the cross-sectional imaging appearance of aortic infections, including aortic valve endocarditis, pyogenic aortitis, mycotic aneurysm and aortic graft infections, with an emphasis on CT, MRI and PET/CT appearance. Teaching Points • Aortic infections are associated with high morbidity and mortality. • CT, MRI and FDG PET/CT play complementary roles in aortic infection imaging. • Radiologists should be vigilant for aortic infection manifestations to ensure timely diagnosis.

Rapidly progressing aneurysm of infected thoracic aorta with pseudoaneurysm formation

A 60-year-old man presented with chest discomfort with fever and high C-reactive protein (CRP). Chest computed tomography (CT) disclosed a mediastinal soft tissue swelling originating from the aortic arch, and gallium-67 single-photon emission CT revealed intense uptake in the same region. We initially suspected mediastinitis and/or a thoracic aortic infection. Antibiotics improved his symptoms and CRP levels. However, a follow-up CT scan 33 days later, revealed an aortic arch aneurysm and the patient was diagnosed with infective aortic aneurysm. Here, we report a rare case of a rapidly progressing aneurysm of infected aorta aortic infection with pseudoaneurysm formation.

Infected (mycotic) aneurysms: spectrum of imaging appearances and management

Infected aneurysms are uncommon. The aorta, peripheral arteries, cerebral arteries, and visceral arteries are involved in descending order of frequency. Staphylococcus and Streptococcus species are the most common causative pathogens. Early clinical diagnosis of infected aneurysms is challenging owing to their protean manifestations. Clinically apparent infected aneurysms are often at an advanced stage of development or are associated with complications, such as rupture. Nontreatment or delayed treatment of infected aneurysms often has a poor outcome, with high morbidity and mortality from fulminant sepsis or hemorrhage. Current state-of-the-art imaging modalities, such as multidetector computed tomography and magnetic resonance imaging, have replaced conventional angiography as minimally invasive techniques for detection of infected aneurysms in clinically suspected cases, as well as characterization of infected aneurysms and vascular mapping for treatment planning in confirmed cases. Doppler ultrasonography allows noninvasive assessment for infected aneurysms in the peripheral arteries. Imaging features of infected aneurysms include a lobulated vascular mass, an indistinct irregular arterial wall, perianeurysmal edema, and a perianeurysmal soft-tissue mass. Perianeurysmal gas, aneurysmal thrombosis, aneurysmal wall calcification, and disrupted arterial calcification at the site of the infected aneurysm are uncommon findings. Imaging-guided endovascular stent-graft repair and embolotherapy can be performed in select cases instead of open surgery. Familiarity with the imaging appearances of infected aneurysms should alert the radiologist to the diagnosis and permit timely treatment, which may include endovascular techniques.

Management of an Abdominal Aortic Aneurysm Infected with Campylobacter Fetus: A Case Report

We present a rare case of an abdominal aortic aneurysm (AAA) infected with Campylobacter fetus. The patient presented with abdominal pain and leukocytosis, without a palpable AAA. Computed tomography (CT) of the abdomen showed a 3.1 x 3.0 cm infrarenal abdominal aneurysm with an extra-aortic fluid collection. At surgery, an in situ graft was placed. Intraoperative aortic wall cultures grew pansensitive C. fetus, and blood cultures remained negative. At 9-month follow-up, the patient was doing well without complaints. To our knowledge, this represents only the ninth reported case of an AAA with an aortic wall culture positive for C. fetus.

Not just an aneurysm, but an infected one: A case report and literature

A mycotic aneurysm is an infected aneurysm. The infection damages and weakens the blood vessel, accelerating a rapid growth of the aneurysm. Mycotic aneurysms are rare, but they have high mortality if diagnosis is delayed or missed. A case report is reviewed of a patient who had multiple aortic aneurysms that were discovered to be mycotic. This case report is followed by a general overview of mycotic aneurysm. Several retrospective studies that were published between 1997 and 2005 were reviewed to help the reader understand the patient population, risk factors, assessment, diagnosis, management, and long-term follow-up of patients with mycotic aneurysms.