Fucoidan interferes with Porphyromonas gingivalis-induced aneurysm enlargement by decreasing neutrophil activation.

PURPOSE: Neutrophils have been shown to be involved in all stages of human and experimental abdominal aortic aneurysm (AAA) development. The initial processes of neutrophil rolling and trapping in the intraluminal thrombus (ILT) are mediated mainly by P-selectin expressed by activated platelets. In the present study, we propose to evaluate the beneficial effect of fucoidan, a competitive binding agent of P-selectin, on aneurysmal growth in a rat model of aortic aneurysm with neutrophil enrichment of the ILT induced by repeated episodes of weak bacteremia. METHODS: Sixty Lewis rats with experimental AAAs, developed from decellularized aortic xenografts, were divided into four groups. Two groups were used as controls: group fucoidan control (FC) was treated with 200 mg of fucoidan (F) delivered by 2 mL, 4-week osmotic pumps placed intraperitoneally before closing the abdomen, and group C received saline instead of fucoidan. Two more groups were injected weekly with Porphyromonas gingivalis (P. gingivalis [Pg]): group F+Pg received 200 mg of intraperitoneal fucoidan and group Pg received saline. AAAs were harvested after 4 weeks and peripheral blood was sampled at that time. Cell-free DNA (cf-DNA) and myeloperoxydase (MPO) antigen concentrations were determined in plasma and in AAA-conditioned media. Histology and P-selectin immunostaining were performed on AAA tissue samples. RESULTS: Comparing rats injected with Pg, those receiving fucoidan presented reduced aneurysmal diameter. Histologic analysis of AAAs showed that fucoidan reduced the ILT thickness in Pg-injected rats, with fewer trapped neutrophils, and with signs of a healing process, as observed in control group C. Immunohistological analysis revealed a substantial decrease in P-selectin immunostaining at the luminal surface of aneurysms in fucoidan-treated rats compared to the other groups, suggesting an interaction between fucoidan and P-selectin. A significant decrease in MPO concentrations in both plasma and conditioned medium was induced by fucoidan treatment in Pg-injected rats, reflecting a pacification of the ILT biological activity. This effect was associated with a reduction in neutrophil activation and apoptosis, reflected by a significant decrease in cf-DNA concentration in both plasma and conditioned medium of fucoidan-treated rats. CONCLUSIONS: Our results suggest that fucoidan has a beneficial effect on experimental aneurysmal degeneration by decreasing neutrophil activation in the ILT enhanced by weak pathogen contamination. This effect seems to be related to its interaction with P-selectin, which may decrease the trapping of neutrophils into the ILT. Fucoidan could represent a therapeutic option in AAAs to decrease the neutrophil activation involved in the degenerative process of aneurysmal expansion and rupture.

Salmonella mycotic thoracoabdominal aortic aneurysm associated with chronic lymphocytic leukemia.

Non-typhoidal Salmonella infections typically cause self-limiting gastroenteritis. However, extraintestinal focal infections, including mycotic aneurysms of the aorta, can also occur. We present the case of a 71-year-old man with chronic lymphocytic leukemia (CLL) and a large type V thoracoabdominal mycotic aneurysm infected with Salmonella enteritidis, complicated by thoracolumbar spondylodiscitis, paravertebral collections, and epidural abscess. This is the first report of Salmonella aortitis in the setting of CLL, and the unusual extent of local infective invasion seen here with Salmonella enteritidis infection raises a suspicion of CLL-related immunosuppression as a direct predisposing factor. This case illustrates the need to consider the possibility of an immune defect, even in CLL patients with normal leukocyte counts. The underlying mechanisms are unclear, but are likely to involve defects in cell-mediated immunity, thought to be of particular importance in invasive infections with intracellular pathogens such as Salmonella spp.

A clinicopathologic study of immunoglobulin G4-related sclerosing disease of the thoracic aorta.

OBJECTIVE: Immunoglobulin G4-related sclerosing disease (IgG4-SD) has recently been reported to occur in the cardiovascular system and manifest as inflammatory abdominal aortic aneurysm. Thoracic aortic lesions are often associated with aortitis in several divergent etiologies. Thus, this study was performed to review thoracic aortic lesions from the aspect of IgG4-SD and to elucidate the clinicopathologic characteristics of this subgroup in the thoracic aorta. METHODS: The study comprised 125 patients, including 71 with thoracic aortic aneurysm (TAA), 44 with aortic dissection, 7 with Takayasu aortitis, and 3 with infectious aortitis. IgG4-SD was identified by diffuse infiltration of numerous IgG4-positive plasmacytes by immunohistochemical examinations. Clinicopathologic features were compared between IgG4-related and IgG4-unrelated lesions. RESULTS: Among the 125 patients, IgG4-SD was found in 5 patients with TAA but was not detected in the other subgroups of thoracic aortic lesion. IgG4-related TAA included one case of lymphoplasmacytic aortitis, 1 case of inflammatory aneurysm, and three cases of atherosclerotic aneurysms. Patients with IgG4-related TAA showed clinicopathologic features similar to patients with IgG4-SD: male gender, old age, history of bronchial asthma and allergies, elevation of white blood cell counts, C-reactive protein levels, and IgG4 and IgE concentrations (in one patient); eosinophilic infiltration, obliterative phlebitis, lymph follicle formation, and perineural inflammation. In addition, compared with IgG4-unrelated TAA, IgG4-related TAA was characterized by clinically more frequency of involvement of the aortic arch (P = .002), saccular formation (P = .003), and fibrous adhesion to surrounding tissue (P < .001), and histopathologically thicker entire aortic wall and adventitia (P < .001 each). CONCLUSIONS: IgG4-SD is involved in 4% of all thoracic aortic lesions and uniformly presents in the form of an aneurysm with distinct histologic and clinicopathologic features. IgG4-SD represents one, albeit rare, etiology of TAA, especially those originating in the aortic arch.

Saprochaete capitata aortitis in an immunocomopetent patient after myocardial revascularization.

Saprochaete species infection is a rare fungal disease reported so far only in immunocompromised patients. We describe the first case of aortitis caused by Saprochaete capitata, presenting as ascending aorta aneurysm, with secondary endophthalmitis in an immunocompetent patient. Infection by Saprochaete capitata is potentially fatal, with a mortality ranging from 50% to 90% of cases. In the present case aortic aneurysm caused by Saprochaete capitata aortitis was successfully treated by the combination of accurate diagnosis with surgical and specific antifungal therapy.

Infectious Aneurysm Caused by Citrobacter koseri in an Immunocompetent Patient.

Citrobacter species can cause severe infection in immunocompetent patients. A 78-year-old man visited our hospital because he had had a fever lasting one day each month for the past 3 months. Antibiotics were initiated for suspected bronchial pneumonia, but the C-reactive protein level remained high. Contrast-enhanced computed tomography revealed saccular brachiocephalic artery aneurysm. Citrobacter koseri was isolated from a blood culture, and he was diagnosed with infectious brachiocephalic artery aneurysm. He underwent endovascular aneurysm repair after one month of intravenous cefepime and metronidazole. We herein report for the first time an immunocompetent patient with infectious aneurysm caused by C. koseri periodontal infection.

Mycotic aneurysm of the distal aortic arch caused by Aspergillus.

We describe an unusual case of a thoracic aortic aneurysm caused by Aspergillus. A 70-year-old man underwent prednisolone and Ara-C treatments for a myelodysplastic syndrome. Blood examination revealed pancytopenia. Under these treatments, an aneurysm presented at the distal aortic arch. He underwent resection of the aneurysm with a graft repair covered by a pedicled omentum flap, followed by prolonged administration of micafungin and itraconazole for a mycotic aneurysm. The postoperative course was favorable without complications. Serum C-reactive protein became negative and he was discharged 2 months after the surgery. However, 4 months after the surgery, he died from worsening of the myelodysplastic syndrome. The prognosis for patients with mycotic aneurysms is poor due to their immunocompetent condition arising from underlying diseases. Therefore, in addition to prompt treatment with antifungal agents combined with surgical debridement, control of the underlying disease is essential for improving the outcome.

Mycotic aortic aneurysms. A reappraisal.

Mycotic aneurysms are uncommon but not rare lesions with potential for catastrophic hemorrhage or sepsis. They have been ascribed to bacterial endocarditis and, when present in the aorta, were termed "inevitably fatal" as recently as 1967. A 15-year review of the English-language literature on mycotic aneurysms showed that arterial trauma, concurrent sepsis, and depressed host immunity have become the cardinal "risk factors" in the development of these lesions. Conventional treatment of mycotic aortic aneurysms usually includes aortic ligation, aneurysmal excision, and extra-anatomic bypass grafting. Nevertheless, four of our patients with well-localized mycotic aortic aneurysms survived three to 54 months (mean, 40 months) after aortic excision and in situ prosthetic graft restoration of aortic continuity. This experience suggests that mycotic aortic aneurysms can be successfully treated, frequently by in situ grafting, if diagnosis and treatment are timely and aggressive.

Multiple intracranial aneurysms due to Coccidioides immitis infection. Case report.

True mycotic (fungal) aneurysms are distinctly uncommon. The case of a young woman with multiple intracranial aneurysms of Coccidioides immitis origin is presented. Coccidioides immitis organisms are not uncommon central nervous system pathogens and usually cause basilar meningitis and hydrocephalus. There are no previous reports of a coccidioidal mycotic aneurysm. The management of intracranial coccidioidomycosis and fungal aneurysms is reviewed.

Mycotic pseudoaneurysm of the aortic arch: an unusual complication of invasive pulmonary aspergillosis.

Invasive pulmonary aspergillosis (IPA) is usually a condition of the immunocompromised patients. The organism has a tendency to invade pulmonary blood vessels. Extension of a pulmonary parenchymal lesion to involve the mediastinal great vessels is very rare. This is the first case where the extension of IPA to the aortic arch and the formation of a pseudoaneurysm were demonstrated on serial CT scans.

Stent-graft implantation for clinically diagnosed syphilitic aortic aneurysm in an HIV-infected patient.

We describe our experience with stent-graft placement in a patient with a clinically diagnosed syphilitic aortic aneurysm.The patient was a 43-year-old man with syphilitic and human immunodeficiency virus (HIV) co-infection. Computed tomography (CT) revealed an aortic aneurysm with 89 mm in maximum size which was located at distal aortic arch and was considered syphilis derived saccular aneurysm. The aneurysm was judged at high risk of rupture from its shape. We decided to perform stent-graft implantation. Before surgery, the patient was given antibacterial and anti-HIV agents. Hand-made fenestrated stent graft by Tokyo Medical University was implanted. The graft was placed from the ascending aorta to Th 9 level in the descending aorta. The aneurysm completely disappeared during follow-up, with no flare-up of syphilitic infection up to 2 years after surgery.The number of patients with syphilis and human immunodeficiency virus co-infection is now increasing. Stent-graft implantation may be an effective treatment in such immunocompromised patients.

Streptococcus pneumoniae mycotic aneurysm with contiguous vertebral discitis treated by endovascular aortic repair and antibiotics.

A 61-year-old man was admitted with a history of right upper quadrant and left iliac fossa pain and raised inflammatory markers. Initial investigations, including contrast-enhanced CT scan of the abdomen and pelvis, were reported as normal. Following readmission 2 months later with thoracolumbar back pain and recurrent fevers, an MRI showed T11/12 discitis and an adjacent mycotic aneurysm of the aorta. CT angiogram confirmed an 8 cm mycotic aneurysm. A second, more distal aneurysm was found located at the left common femoral artery. The aortic aneurysm was treated by antegrade stenting. The left common femoral artery aneurysm was excised. The patient was also treated with antibiotics. He made a good recovery and was well 8 months later apart from mild residual thoracolumbar spinal pain. To date, he has been followed up for 1 year and remains asymptomatic.

Rapidly growing aortic arch aneurysm in Behcet's disease.

We present a patient with a nine-year history of Behçet's disease (BD), who developed a rapidly expanding aneurysm of the aortic arch. Three-dimensional computed tomography demonstrated a saccular aortic arch aneurysm with a maximal diameter of 5 cm. No bacteria were detected by serial blood cultures. The aneurysm, however, showed a multi-lobular cavity, mimicking an infectious aneurysm. Therefore, we prescribed antibacterial agents for one week. The patient still had a high-fever and an elevated C-reactive protein level thereafter. Aortic arch replacement was performed emergently. Because we were unable to determine whether the aneurysm was caused by infection or BD, the implanted prosthetic graft and the anastomotic sites were covered with a pedicle graft of the greater omentum, and we continued to administer antibacterial agents for four weeks postoperatively. The pathological examination showed neither bacteria nor cystic medial necrosis in the resected aortic wall. Inflammatory changes with eosinophilic infiltration were recognized mainly around the adventitia near the aneurysm. The patient had a favorable postoperative course without any complications.