Preterm infant with necrotizing enterocolitis and arteritis secondary to streptococcus gallolyticus subspecies pasteurianus

 Streptococcus gallolyticus subspecies pasteurianus is a subtype of Streptococcus bovis (S. bovis) that has become increasingly recognized as a sepsis-causing pathogen in neonates. It is well documented that S. bovis species have a predilection to both cardiac and gastrointestinal tissue, and in adult populations, isolating these organisms in the bloodstream often triggers further evaluation for co-morbid complications such as colon cancer or endocarditis. However, no such guidance currently exists in neonatal literature. We present a case of a preterm infant with S. gallolyticus subsp. pasteurianus bacteremia presenting as necrotizing enterocolitis (NEC) not previously described in the literature. Furthermore, through a complete diagnostic evaluation, including an echocardiogram, our patient was found to have the rare complication of endocarditis.

Aspergillus spp. renal arteritis after kidney transplantation: A reappraisal

BACKGROUND

Aspergillus spp. is an uncommon and life-threatening cause of transplantrenal artery pseudoaneurysm after kidney transplantation.

CASE

We report the case of a 62-year-old woman who underwent kidney transplantation 10 months before and presented a 7-cm asymptomatic transplant renal artery pseudoaneurysm. Transplanted kidney and pseudoaneurysm were surgically removed in emergency. Renal graft, urine, and pseudoaneurysm cultures grew Aspergillus flavus. She recovered after 12 months of antifungal therapy.

LITERATURE REVIEW

To date 14 cases of Aspergillus spp. renal arteritis after kidney transplantation have been published, including 50% Aspergillus flavus arteritis. Vast majority were diagnosed within 90 days after transplantation (73%). Despite allograft nephrectomy and antifungal therapy, mortality rate was high (33%).

Microbiota control acute arterial inflammation and neointimal hyperplasia development after arterial injury

BACKGROUND

The microbiome has a functional role in a number of inflammatory processes and disease states. While neointimal hyperplasia development has been linked to inflammation, a direct role of the microbiota in neointimal hyperplasia has not yet been established. Germ-free (GF) mice are an invaluable model for studying causative links between commensal organisms and the host. We hypothesized that GF mice would exhibit altered neointimal hyperplasia following carotid ligation compared to conventionally raised (CONV-R) mice.

METHODS

Twenty-week-old male C57BL/6 GF mice underwent left carotid ligation under sterile conditions. Maintenance of sterility was assessed by cultivation and 16S rRNA qPCR of stool. Neointimal hyperplasia was assessed by morphometric and histologic analysis of arterial sections after 28 days. Local arterial cell proliferation and inflammation was assessed by immunofluorescence for Ki67 and inflammatory cell markers at five days. Systemic inflammation was assessed by multiplex immunoassays of serum. CONV-R mice treated in the same manner served as the control cohort. GF and CONV-R mice were compared using standard statistical methods.

RESULTS

All GF mice remained sterile during the entire study period. Twenty-eight days after carotid ligation, CONV-R mice had significantly more neointimal hyperplasia development compared to GF mice, as assessed by intima area, media area, intima+media area, and intima area/(intima+media) area. The collagen content of the neointimal lesions appeared qualitatively similar on Masson's trichrome staining. There was significantly reduced Ki67 immunoreactivity in the media and adventitia of GF carotid arteries 5 days after ligation. GF mice also had increased arterial infiltration of anti-inflammatory M2 macrophages compared to CONV-R mouse arteries and a reduced proportion of mature neutrophils. GF mice had significantly reduced serum IFN-γ-inducible protein (IP)-10 and MIP-2 5 days after carotid ligation, suggesting a reduced systemic inflammatory response.

CONCLUSIONS

GF mice have attenuated neointimal hyperplasia development compared to CONV-R mice, which is likely related to altered kinetics of wound healing and acute inflammation. Recognizing the role of commensals in the regulation of arterial remodeling will provide a deeper understanding of the pathophysiology of restenosis and support strategies to treat or reduce restenosis risk by manipulating microbiota.

[In situ arterial allografting for aortoiliac infection]

From January 2009 to January 2013, we treated 83 patients for aortoiliac infection by resection of all infected material and in situ revascularization with an arterial allograft. Thirteen patients (15.7 %) died during the first month or before discharge. Perioperative mortality was associated with the presence of a visceral fistula: five deaths (27.8%) occurred among the 18 patients with a visceral fistula, and8 (12.3 %) among the 65 without a visceral fistula (p = 0.11). These results confirm those of our previous studies regarding the severity of aortoiliac infection, especially in patients with a visceral fistula, and endorse our in situ allografting strategy.

Evolution of bacterial arteritis into a mycotic aortic aneurysm

Arteritis and mycotic aneurysms have been well described for more than 100 years. The authors report a case of bacterial arteritis that presented with pneumatosis of the aortic wall and that evolved over 1 week into an infected abdominal aortic aneurysm. This case documents the rapid progression from arteritis to mycotic aneurysm, highlighting the need for close radiologic follow-up and aggressive medical and surgical management.

Candida albicans arteritis transmitted by conservative liquid after renal transplantation: a report of four cases and review of the literature

BACKGROUND

Mycotic arteritis and/or aneurysms are infrequent complications of renal transplantation. They are mostly secondary to bacterial infection and rarely to Candida albicans. We report four cases of mycotic arteritis due to C. albicans after renal transplantation but which have been inoculated during organ harvesting or conservation.

METHODS

In all the four cases corresponding to two independent donors, C. albicans was isolated few days later in the systematic culture of the conservative liquid. We also review the clinical features and outcomes of 13 cases previously reported in the literature.

RESULTS

In two cases, the diagnosis of fungal arteritis was confirmed only during autopsy after the patient's death due to massive bleeding. In the other two cases, the diagnosis was made on the arterial section of the anastomotic wall after detransplantation for massive bleeding for arterial leakage although an immediate antifungal treatment with fluconazole and caspofungin was given and was found to be inefficient.

CONCLUSION

This is a serious complication of renal transplantation because it leads to graft loss in the majority of the cases and even to death in a few cases despite an efficient and rapid treatment. Routine fungal cultures of preservation media are important for early diagnosis and timely surgical interventions are life-saving.

Lethal and severe coronary arteritis in DBA/2 mice induced by fungal pathogen, CAWS, Candida albicans water-soluble fraction

CAWS is a microbial pathogen-associated molecular patterns (PAMPs) produced by Candida albicans. CAWS is a mannoprotein-beta-glucan complex and secreted into the culture supernatant. CAWS has various biological effects, causing acute shock and disrupting vascular permeability. Intraperitoneal administration of CAWS induces coronary arteritis in various strains of inbred mice. The CAWS-induced coronary arteritis is strain-dependent and most severe in DBA/2 mice with a significant number of these animals expiring with cardiomegaly during the observation period. In vivo and in vitro, splenocytes of DBA/2 mice produced various cytokines, such as IL-6, TNF-alpha, and IFN-gamma in response to CAWS. GM-CSF was also produced in response to CAWS. The production of cytokines was significantly enhanced in the presence of recombinant GM-CSF. In contrast, anti-GM-CSF significantly reduced the production of TNF-alpha and IFN-gamma. Augmented production of cytokines in response to CAWS would be a key to the severity of coronary arteritis.

Escherichia coli femoral arteritis: case report and literature review

Primary infectious arteritis is exceptional and remains a challenging problem. The etiology of these infections changed in recent years. The authors report a case of isolated thrombosed infected common femoral artery. They discuss the different mechanisms leading to infection, the work-up and the current treatment options.

Greffe rénale et artérite du greffon à Candida albicans

INTRODUCTION

Candida arteritis can compromise the functional prognosis of the graft or even the life of the transplant recipient. The infection can be transmitted by the graft.

OBSERVATION

A 46 year-old woman contracted a Candida albicans ateritis of the graft following a kidney transplant that led to a detransplantation. The yeast was probably transmitted by the graft from the donor, source of an unknown candida infection: it was found in the conservation liquid of the graft itself, and in the renal artery and vascular pedicle. Analysis of of these three elements by enzymatic electrophoresis showed that they were identical.

COMMENTARIES

This case report underlines the need to establish guidelines and sanitary safety measures, notably that of systematically placing in culture the concervation solutions and alerting the transplant team if any fungi are isolated.

Using 18-fluoro-2-deoxyglucose positron emission tomography in detecting infectious endocarditis/endoarteritis

RATIONALE AND OBJECTIVES

We evaluated the effectiveness of positron emission tomography (PET) with 18-fluoro-2-deoxyglucose (FDG) in the detection of infectious endocarditis/endoarteritis.

MATERIALS AND METHODS

For this study, we recruited 6 patients (4 women, 2 men; age range, 35 - 78 years; mean age, 55.8 +/- 16.8 years) who were clinically diagnosed as having infective endocarditis/endoarteritis by their echocardiographic findings and by Duke criteria.

RESULTS

For all 6 patients, we also found increased FDG uptakes in the corresponding areas detected in echocardiography.

CONCLUSION

FDG-PET appears to be a promising tool in diagnosing infective endocarditis/endoarteritis, and further prospective studies on a large scale to fully exploit the usefulness of FDG-PET for infective endocarditis/endoarteritis are needed.

Histopathological features of murine systemic vasculitis caused by Candida albicans extract--an animal model of Kawasaki disease

OBJECTIVE AND DESIGN

We examined the histopathological features of systemic vasculitis caused in mice by injection of a Candida albicans ( C. albicans) extract and investigated the principal genetic roles in the development of vasculitis.

MATERIALS AND METHODS

C. albicans extract was injected intraperitoneally for five consecutive days in the 1st and 5th weeks to CD-1, C57BL/6N, C3H/HeN, BALB/cAnN, DBA/2N and CBA/JN mice. At week 8, mice were killed, and histological examination was performed by light microscopy.

RESULTS

Arteritis had developed in 66% of CD-1 mice. The extramural coronary arteries and aortic root close to the orifice of coronary arteries were most frequently involved. Histologically, the characteristic feature of the arteritis was proliferative and granulomatous inflammation accompanied by numerous macrophages, lymphocytes, plasma cells and neutrophils. Fibrocellular intimal thickening with destruction of the internal elastic lamina and media was also observed. Five mouse strains after injection of C. albicans extract were clearly classified into a resistant group (CBA/JN, DBA/2N and BALB/cAnN mice) and a sensitive group (C3H/HeN and C57BL/6N mice). The inbred mouse strains which showed the same histocompatibility-2 (H-2) haplotype exhibited a different susceptibility to development of vasculitis.

CONCLUSION

This arteritis murine model shows unique histological features that have not been observed in other animal vasculitis models and it most closely resembles Kawasaki disease in humans. The genetic control of susceptibility to induction of vasculitis by the C. albicans extract is dependent to the mouse strains, but is not linked to the H-2 loci.

Human pythiosis, a rare cause of arteritis: case report and literature review

OBJECTIVE

To present a case of Pythium insidiosum arteritis and review reported cases of human pythiosis.

METHODS

Search of MEDLINE (PubMed) and the Thai Index Medicus was performed using the words "pythiosis" and "pythium." Search of abstracts from a scientific meeting also was performed. Only reported cases in the English or Thai language, with enough clinical information for analysis, were included.

RESULTS

There were a total of 32 cases of human pythiosis, with 31 identified in the literature. Twenty-five cases were Thai. Twenty of 21 patients with known occupations were farmers. There was ocular infection in 9 cases, subcutaneous infection in 5 cases, arterial infection in 17 cases, and cardiopulmonary infection in 1 case. Thalassemia was a common associated finding. In addition to systemic antifungal therapy, surgery was required in most cases. The highest mortality rate was seen in the arteritic form, particularly in patients with arterial lesions proximal to the superficial femoral artery.

CONCLUSIONS

Human pythiosis is rare. Physicians should be suspicious of pythiosis in individuals, particularly farmers in Thailand, who develop nonhealing cutaneous ulcers or keratitis, which do not respond to conventional treatment. P insidiosum infections should be listed as a rare cause of infectious arteritis.

Lethal subarachnoid bleeding under immunosuppressive therapy due to mycotic arteritis

A subarachnoid haemorrhage (SAH) occurred 67 days after cardiac transplantation in a 10-year-old girl with consecutive immunocompromising therapy. Neither digital subtraction angiography (DSA) nor computed tomographic angiography showed signs of intracranial vascular malformations. One month before the lethal SAH occurred, she had developed arterial hypertension and attacks of severe headache with cerebrospinal fluid (CSF) pleocytosis while CT scans showed an infarct of the left thalamus. Pathologic findings established the rare diagnosis of SAH due to aspergillosis-related mycotic arteritis. Imaging characteristics are presented.

Femoral endarteritis associated with percutaneous suture closure: new technology, challenging complications

OBJECTIVE

Use of percutaneous suture closure devices after catheter-based interventions is increasing. We recently have seen several severe femoral arterial wall infections after use of such devices. The purpose of this study was to examine the incidence, comorbid associations, and management of femoral arterial infections associated with percutaneous suture closure devices.

METHODS

We retrospectively reviewed all infectious complications that occurred after 2223 consecutive cardiac catheterization procedures performed over 12 months in a university-affiliated community teaching hospital. Outcome variables included demographics, procedural details, infection, type of arterial reconstruction required, mortality, and limb loss.

RESULTS

During this study, 822 patients received percutaneous suture devices. Infection developed in 6 patients (0.7%). The incidence of diabetes in the population undergoing percutaneous suture closure was 219 of 822 patients (26.6%). Three comorbid conditions, noted in multiple patients with infectious complications, included diabetes mellitus, obesity, and placement of a percutaneous suture closure device within the past 6 months. Invasive femoral endarteritis developed in 4 patients. Gram-positive cocci predominated in 4 patients. In 1 patient with polymicrobial infection catastrophic complications developed, including multiple anastomotic ruptures and hemorrhage. A new method of repair that incorporated double-thickness everted saphenous vein was used in 2 patients, and safe arterial closure was achieved. There was 1 late fatality on postoperative day 36. Limb salvage was achieved in all patients.

CONCLUSIONS

Femoral endarteritis complicating percutaneous suture closure is a challenging new problem for vascular surgeons and can result in catastrophic complications. Customary techniques that use saphenous vein patch or interposition grafting are not adequate in all circumstances. Successful outcome requires operative exploration in patients with suspected infection. Removal of the percutaneous suture closure device and debridement to normal arterial wall is recommended in all patients with suspected femoral endarteritis, based on positive intraoperative Gram stains or abnormal appearance of the adjacent femoral artery. Early success with an autologous bolstered repair is reported. Caution is advised when considering the use of a percutaneous suture closure device in patients with comorbid conditions including diabetes, obesity, and previously implanted devices.

Superantigenic activity is responsible for induction of coronary arteritis in mice: an animal model of Kawasaki disease

Kawasaki disease (KD) is a multisystem vasculitis and the leading cause of acquired heart disease in children of the developed world. Lactobacillus casei cell wall extract-induced coronary arteritis in mice mirrors KD in children. Here, we report that responses to L. casei cell wall extract possess all the hallmarks of a superantigen-mediated response: marked proliferation of naive T cells, non-classical major histocompatibility restriction with a hierarchy in the efficiency of different class II molecules to present this superantigen, a requirement for antigen presentation, but not processing, and stimulation of T cells in a non-clonal, TCR V(beta) chain-dependent fashion. This superantigenic activity directly correlates with the ability to induce coronary arteritis in mice. Taken together, our findings demonstrate that superantigenic activity in L. casei cell wall extract is responsible for induction of coronary artery disease.

Fatal subarachnoid hemorrhage, with brainstem and cerebellar infarction, caused by Aspergillus infection after cerebral aneurysm surgery: case report

OBJECTIVE AND IMPORTANCE

Intracranial aspergillosis has been reported to cause subarachnoid hemorrhage (SAH) attributable to ruptured mycotic aneurysms. We describe a case of Aspergillus arteritis that caused SAH without aneurysm formation, followed by successive brainstem and cerebellar infarction.

CLINICAL PRESENTATION

A 50-year-old woman experienced a sudden onset of headache. Computed tomography demonstrated SAH. After angiography revealed an aneurysm of the anterior communicating artery, a complete neck-clipping operation was performed, without neurological deterioration. However, the patient experienced another episode of SAH on the 26th postoperative day.

INTERVENTION

We repeated the craniotomy and confirmed that the clip was still intact. A second angiographic evaluation did not reveal an aneurysm or any other cause of hemorrhage. On the 30th postoperative day, magnetic resonance imaging demonstrated cerebellar infarction in the territory of the anteroinferior cerebellar artery. The patient died on the 40th postoperative day, after another episode of SAH and progressive cerebellar and brainstem infarction. The postmortem examination revealed destruction of the basilar artery and occlusion of the basilar and vertebral arteries attributable to Aspergillus arteritis.

CONCLUSION

When a patient presents with SAH of unknown origin followed by cerebral infarction, Aspergillus arteritis should be included in the differential diagnosis. Earlier recognition of this fungal infection improves the prognosis.

Chlamydia pneumoniae infection and nonspecific aortoarteritis: search for a link with a nonatherosclerotic inflammatory arterial disease

BACKGROUND

The association between Chlamydia pneumoniae infection and atherosclerosis has gained recognition. However, the nature of this association is controversial. The infective link may not be specific for atherosclerosis and may also exist in other nonatherosclerotic arterial diseases. We investigated patients with nonspecific aortoarteritis for serological evidence of prior Chlamydia pneumoniae infection.

METHODS AND RESULTS

Fifty patients each of nonspecific aortoarteritis and coronary artery disease with angiographic evidence of significant (>70%) coronary artery lesions were tested for the presence of IgG antibodies against Chlamydia pneumoniae by micro-immunofluorescence assay and compared with 50 age- and sex-matched normal healthy controls. The number of patients with nonspecific aortoarteritis who tested positive for Chlamydia pneumoniae antibodies (IgG) was not significantly different from controls (8 v. 7, p=ns). The mean titer amongst positive subjects in the two groups was also similar (1:40+/-40 v. 1:50+/-25; p=ns). Patients with coronary artery disease were significantly older than patients with nonspecific aortoarteritis and controls (53.2+/-5.8 v. 21.2+/-9.9 years and 24.5+/-5.2 years, p<0.01 for both) and showed a higher seroprevalence of prior Chlamydia pneumoniae infection (18 v. 8 and 7, p < 0.05 for both). The mean IgG titers of patients with coronary artery disease who tested positive were also significantly higher than the other two groups (1:98+/-34 v. 1:40+/-40, p<0.001 and 1:98+/-34 v. 1:50+/-25, p<0.01, respectively).

CONCLUSIONS

In patients with nonspecific aortoarteritis, the seroprevalence of prior Chlamydia pneumnoniae infection is not more than that in healthy individuals of the same age group, but is significantly lesser than that in patients with coronary artery disease. Thus Chlamydia pneumoniae infection may not be associated with all forms of chronic inflammatory arterial lesions.

Case report. Mycotic arteritis due to Aspergillus fumigatus in a diabetic with retrobulbar aspergillosis and mycotic meningitis

A 74-year-old man with diabetes mellitus type II, retinopathy and polyneuropathy suffered from exophthalmus, ptosis and diplopia. Magnetic resonance imaging and computer tomography showed a space-occupying process in the right orbital apex. An extranasal ethmoidectomy accompanied by an orbitotomia revealed the presence of septated hyphae. Aspergillus fumigatus was grown from the tissue. After surgical removal of the fungal masses, therapy with amphotericin B (1 mg kg(-1) body weight) plus itraconazole (Sempera, 200 mg per day) over 6 weeks was initiated. Five months later the patient's condition deteriorated again, with vomiting, nausea and pain behind the right eye plus increasing exophthalmus. Antifungal therapy was started again with amphotericin B and 5-fluorocytosine. Neutropenia did not occur. The patient became somnolent and deteriorated, a meningitis was suggested. Aspergillus antigen (titre 1:2, Pastorex) was detected in liquor. Anti-Aspergillus antibodies were not detectable. Both the right eye and retrobulbar fungal masses were eradicated by means of an exenteratio bulbi et orbitae. However, renal insufficiency and an apallic syndrome developed and the patient died. At autopsy, a mycotic aneurysm of the arteria carotis interna dextra was detected. The mycotic vasculitis of this aneurysm had caused a rupture of the blood vessel followed by a massive subarachnoidal haemorrhage. In addition, severe mycotic sphenoidal sinusitis and aspergillosis of the right orbit were seen, which had led to a bifrontal meningitis.

A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase-antineutrophil cytoplasmic autoantibodies

A 53-year-old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X-ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium-macroaggregated albumin (99mTc-MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)-antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non-specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO-ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO-ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO-ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.

Subclavian arteritis and pseudoaneurysm formation secondary to stent infection

Technically uncomplicated percutaneous angioplasty and stent placement of a left subclavian artery stenosis was performed in a 56-year-old man for treatment of subclavian steal syndrome and vertebrobasilar insufficiency. Six days later the patient was readmitted with Staphylococcus aureus bacteremia and stigmata of septic emboli isolated to the ipsilateral hand. Nine days later he had computed tomography (CT) evidence of a contrast-enhancing phlegmon surrounding the stent. Despite clinical improvement and resolution of bacteremia on intravenous antibiotic therapy, the phlegmon progressed, and at day 21 a pseudoaneurysm was angiographically confirmed. The patient underwent surgical removal of the stented arterial segment and successful autogenous arterial reconstruction. The possible contributory factors leading to stent infection were prolonged right femoral artery access and an infected left arm venous access. Although the role of prophylactic antibiotics remains to be defined, it may be important in cases where the vascular access sheath remains in place for a prolonged period of time.

Isolated pontine infarction due to rhinocerebral mucormycosis

We report a patient with rhinocerebral mucormycosis whose initial central nervous system involvement was isolated pontine infarction due to basilar arteritis caused by the fungus. The patient was diagnosed and followed by MRI and CT and basilar arteritis was demonstrated well on MRI studies. Involvement of the skull base was shown on CT in the later stage of the disease. The unusual initial presentation of the infection is discussed.

The use of arterial allografts in aortic graft infections. A three year experience on eighteen patients

BACKGROUND

We describe our experience in the treatment of aortic graft infections by replacing them with arterial homografts as suggested by the good results recently described.

METHODS

Between March 1994 and March 1997 eighteen patients with infections of the aortofemoral bifurcation segments have been treated. All patients underwent a complete explantation of the infected graft and an in situ revascularization with arterial homograft harvested in multiorgan removal. Eight segments were freshly preserved, 10 were cryopreserved. Four patients were operated as emergencies, of which 3 for aorto-enteric fistulas. All others presented a serious septic state.

RESULTS

Three patients died in the early postoperative period: one of acute infarction and two of homograft related causes. In the follow-up there was only one death from acute infarction, a branch occlusion and two allograft enteric fistulas successfully treated by surgery. All surviving patients are submitted to periodical haemodynamic and tomographic control with an average follow-up of 22 months (range 3 months to 3 years) and there has been no allograft degeneration so far.

CONCLUSIONS

The use of homologue arterial allografts has shown good results in the treatment of serious aortic graft infections resulting in adequate peripheral vascularization. There have been no significant degenerations to date, either in fresh or cryopreserved allografts.

Arteritis and fatal subarachnoid hemorrhage complicating occult Candida meningitis: unusual presentation in pediatric acquired immunodeficiency syndrome

We report the case of an 11-month-old child with acquired immunodeficiency syndrome, who despite treatment for systemic candidiasis developed undetected Candida meningitis. This uncommon manifestation of candidiasis was accompanied by basilar granulomatous inflammation and fibrosis of meninges with arteritis, vascular invasion by fungi, and terminal subarachold hemorrhage. To our knowledge, this constellation of findings has not been reported previously in pediatric acquired immunodeficiency syndrome.

Infection of endovascular stents in a swine model

BACKGROUND

Percutaneous balloon angioplasty with intravascular metallic stent placement has rapidly gained popularity for the treatment of arterial occlusive disease. Although the incidence of vascular prosthetic infection is well described, the risk of infection following metallic stent placement is unknown. The purpose of this study was to determine if intravascular metallic stents could become infected following systemic bacterial challenge.

METHODS

Balloon expandable metallic stents were implanted in the iliac arteries of 10 swine following balloon catheter angioplasty. A second angioplasty, without stent placement, was also performed in the contralateral iliac artery. A bacterial challenge with Staphylococcus aureus was then infused into the aorta immediately after stent placement. Group 1 (n = 5) was killed at 72 hours, and group 2 (n = 5) at 3 weeks. A third group (n = 5) underwent stent placement without bacterial challenge and was killed at 3 weeks. At the time of death, the stents were cultured, and both iliac arteries were submitted for pathologic examination. Arterial patency and evidence of systemic infection were also assessed.

RESULTS

In the animals sacrificed at 72 hours (group 1), 80% had stent cultures with significant growth of S aureus; while at 3 weeks (group 2), 60% of cultures were positive. Of the stents placed without bacterial challenge (group 3), none had a positive culture at 3 weeks. In group 2, 40% of the stented arteries remained patent, while 100% of group 3 remained patent until sacrifice at 3 weeks. All of the stented arteries which were patent at 3 weeks were culture negative, while all those which were thrombosed were culture positive for S aureus. When compared to angioplasty alone, the presence of a stent was strongly associated with pathologic evidence of inflammation [93% versus 7%]. The quality of inflammation in the stented groups also differed. Ninety percent of the stented arteries in groups 1 and 2 had acute inflammation, compared to only 20% in group 3. The remainder of the stented arteries in group 3 had chronic inflammation or were normal.

CONCLUSION

In the swine model, intravascular metallic stents have the potential to become infected. This is associated with acute inflammation of the arterial wall and vessel thrombosis. Further studies evaluating the incidence of stent infections in humans are needed.

Candida arteritis: are GI endoscopic procedures a source of vascular infections?

A 53-year-old woman, 11 years after a renal transplant on chronic immunosuppression, presented with a sudden onset of a painless left groin mass. Ultrasound revealed a 3 cm common femoral artery pseudoaneurysm and a 3 cm saccular aneurysm of the infrarenal aorta. Operative repair was excision and patch angioplasty of the aortic aneurysm with internal iliac artery and interposition grafting of the femoral artery aneurysm with saphenous vein. Postoperatively, Candida albicans was identified in the aortic and common femoral arterial cultures. Candida infections often occur in patients with impaired cellular immunity due to seeding from urinary tract infections, vascular catheters, or manipulation of the gastrointestinal tract. Our patient, without any prior history of a fungal infection, had undergone a colonoscopy 3 weeks earlier. Without any other possible source being identified, the proposed mechanism for fungal entry into the vascular system was via the gastrointestinal tract, with seeding from the portal venous system. The exact medical and surgical management of these patients remains undefined, and a transplant vascular registry is really needed. However, immunocompromised solid organ transplant recipients undergoing gastrointestinal endoscopic procedures may be at a greater risk for the development of subsequent septicemia. Further reports are really needed to confirm the possible need in these patients for both periprocedural antibiotic and antifungal prophylactic coverage.

Destructive allograft fungal arteritis following simultaneous pancreas-kidney transplantation

Fungal arteritis of the Y graft used to revascularize the whole pancreas graft developed in 2 recipients of simultaneous pancreas-kidney transplant that were performed within 36 hr of each other. The vascular infection became manifest 6-7 days following transplantation. In both patients, the vasculitis culminated in an arterial rupture that required immediate operative intervention. This compromise of the Y grafts contributed to loss of both pancreatic grafts and necessitated vascular reconstruction to reperfuse the lower extremity. To date, both patients continue to experience normal kidney transplant function.

The arteritides

This article reviews the histopathological, clinical and immunological features of the arteritides. Based on these criteria, a classification scheme is proposed that includes infectious and non-infectious causes. Included in the non-infectious arteritides are: hypersensitivity vasculitis including serum sickness. Henoch-Schönlein purpura, mixed cryoglobulinaemia, hypocomplementaemia, drug and malignancy-associated vasculitis; arteritides of small and medium-sized arteries including polyarteritis nodosa, Kawasaki's disease, Wegener's granulomatosis, Churg-Strauss syndrome, necrotizing sarcoid granulomatosis, thromboangiitis obliterans (Buerger's disease) and localized forms of arteritis; arteritides involving large, medium and small-sized arteries which includes giant cell (temporal) arteritis, Takayasu's disease and arteritis of collagen-vascular disease (rheumatoid arthritis, rheumatic fever, Behçet's disease, Sjörgren's syndrome, systemic lupus erythematosis and systemic sclerosis.

[The past, present and future of arterial infection]

Today, the pathology of large and medium-sized arteries is in most part considered as degenerative or inflammatory. The role of infection has been preponderant (syphilis) but has become quite modest now, restricted to infectious aneurysms. According to certain observations, infections may participate in initiating arterial inflammation, whether it be specific (Kawasaki's disease, Takayasu's arteritis, coronary artery disease of cardiac grafts) or less so ("plain" atherosclerosis). Suspected microbes (herpes viruses, Chlamydia pneumoniae, etc.) would damage the arterial wall either directly by infecting it, or indirectly by provoking an autoimmune reaction against some of its components (e.g. heat shock proteins). These hypotheses are worth serious consideration because, if established as correct, they would modify radically our etiologic, therapeutic and prophylactic conceptions of arterial diseases, including of course the main one, atherosclerosis.

Diagnostic features and management of bacterial arteritis with false aneurysm formation

Primary bacterial arteritis with false aneurysm formation is an uncommon condition. This report presents seven patients admitted to one unit over a 5-year period. Interesting aspects of the clinical presentation are discussed. The importance of surgical debridement, extra-anatomic bypass, antibiotic therapy and antibiotic irrigation of the infected aneurysm cavity is stressed. The relative merits of extra-anatomic bypass and in situ grafting for aortic infection are discussed. By following these principles, this series of patients have had a successful surgical outcome and all the signs of infection have been eradicated.

Intracranial aspergillosis producing cavernous sinus syndrome and rupture of internal carotid artery

A case of invasive, intracranial aspergillosis in a non-immunocompromised patient, complicated by rupture of the internal carotid artery due to fungal arteritis, is presented. The computed tomography and magnetic resonance imaging findings are discussed. This is a rare condition with a poor prognosis and requires a high level of suspicion when paranasal sinus disease is detected.

Can we prevent long term cardiac damage in Kawasaki disease? Lessons from Lactobacillus casei cell wall-induced arteritis in mice

A single intraperitoneal injection of sonicated cell walls from group B Lactobacillus casei (LC) produces an acute inflammatory coronary arteritis in mice that closely resembles the coronary arteritis found in children with Kawasaki Disease (KD). The coronary arteritis is accompanied in its early stages by pancarditis and valvulitis, and in its later stages by coronary artery aneurysms, stenoses, and myocardial infarctions. The importance of this model is two-fold. First, it provides the opportunity to study the natural history of coronary artery disease over a relatively short life span. Second, it provides a model system in which the effects of immunological and pharmacological interventions may be tested without putting human life at risk. Studies to date indicate that inflammatory coronary arteritis such as occurs in this model and in children with KD is associated with the accelerated development of coronary artery insufficiency and premature death from cardiovascular disease. The use of immunomodulators or other agents early in the disease course to reduce the frequency and severity of the coronary arteritis appears to reduce the incidence of premature death in this mouse model and may reduce the consequences of KD as well.

Fatal arteritis due to Pythium insidiosum infection in patients with thalassaemia

Six thalassaemic patients had a distinct clinical syndrome characterized by progressive ischemia of the lower extremities, with ascending arteritis and thrombosis of the main arteries of the lower limbs. With periodic acid Schiff and Gomori's methenamine silver staining a large number of hyphae were revealed in the arterial wall and the outer part of the thrombus. Pythium insidiosum was isolated from 3 patients. The clinical course of the disease was progressive gangrene of the extremities and the patients invariably died when the infectious process reached the bifurcation of the aorta. There is no effective antimicrobial agent for the syndrome and radical amputation was the only method to ensure survival of the patients. P. insidiosum infection should be considered in thalassaemic patients with leg ulcers or arterial occlusion of the lower limbs.

[Features of the patho-morphology of arteriopathies associated with viral and infra-microbial infections]

Presence of Mycoplasma Chlamydia, Rickettsia burnetii, influenza type B, herpes and adenoviruses was detected by immunofluorescence in artery fragments collected from patients with arteriopathy. Pathohistological examination of the samples revealed inflammatory--lympho-histiocytic infiltration--and mostly dystrophic alterations. Arteriopathies were localised mostly at the pelvic limb level, especially on femoral artery. Their incidence was statistically significant.

Genomic variability among globally distributed isolates of equine arteritis virus

Equine arteritis virus (EAV), a non-arthropod borne togavirus, has been shown to have a global distribution. To date, no major antigenic variation has been demonstrated between EAV isolates from different geographic origins. In this study, the genomic RNA of EAV isolates obtained from horses of different breeds in various countries around the world was oligonucleotide fingerprinted. Comparisons of these fingerprints were used to determine the extent of genomic variation among such isolates. Comparisons among isolates from North American horses revealed, for the most part, oligonucleotide homologies of less than 60%. Only 29 of the 98 comparisons revealed greater than 60% oligonucleotide homology. Nonetheless, several comparisons indicated a close epidemiologic relationship between isolates from horses of different breeds located in different states. Though all European isolates were of Standardbred origin and were from horses located in northern European countries, the majority had oligonucleotide homologies of less than 60%. Where oligonucleotide homology was apparent, it was, with one exception, greater than 70%. The two isolates from New Zealand had 93.2% oligonucleotide homology. This is indicative of an extremely close epidemiologic relationship. Comparisons between EAV isolates from around the world revealed oligonucleotide homologies between viruses from North America, Europe and New Zealand. In several instances, this homology was greater than 70% and in one case greater than 80%. No oligonucleotide homology was evident in comparisons involving the virus from South Africa. The high level of genomic conservation between certain EAV isolates of disparate geographic origins may reflect dissemination of the virus associated with the international movement of horses. The extent of genomic variation demonstrated between most of the EAV isolates used in this study confirms the need for further investigation of genomic heterogeneity among strains of this virus before techniques that rely upon nucleic acid hybridization can be effectively applied as diagnostic procedures.

Arteritis due to Salmonella with aneurysm formation: two cases

Although arterial infection due to Salmonella is rare, it remains one of the most common causes of primary mycotic aneurysms. The presentation is one of sepsis, cultures positive for Salmonella and rapid expansion or rupture of the aneurysm. The authors' experience at Victoria Hospital, London, Ont., includes two cases of aneurysms infected with Salmonella--one aneurysm of the aorta and the other of the common femoral artery. Both patients were treated by excision of the aneurysm, extra-anatomic reconstruction in an area remote from the infected field and long-term administration of appropriate antibiotics. One patient was alive and well 36 months after resection. The other died of multiple organ failure 10 days after resection. From a review of the English and French literature since 1948, 64 cases of abdominal aortic aneurysms infected with Salmonella were found; half of the patients survived the perioperative period. The diagnosis of mycotic aneurysm must be considered in any patient with an aneurysm and culture specimens positive for Salmonella. The authors favour wide débridement of the infected aneurysm with extra-anatomic reconstruction. This view is supported by a review of the literature. The appropriate antibiotic therapy is bactericidal rather than bacteriostatic.

[Three cases of virus isolation from horse fetuses diagnosed with equine arteritis virus (EAV) abortion from stud farms with different breeds]

Three cases of abortions were diagnosed as caused by Equine Arteritis Virus (EAV) by isolation and typing of this virus from the respective fetuses. All 3 abortions were single cases, one occurring on a stud with Iceland Ponies, one with Warmbloods, one with Lipizzaner horses. On each stud horses of the respective breed were kept exclusively, therefore there existed no epidemiologic link. By means of seroneutralization tests performed on in contact horses it could be shown, that EAV had only been introduced recently into the stud with the Iceland Ponies. An extraneous mare stabled temporarily for covering by the stud's stallion could be incriminated for introducing EAV. By means of post-abortion serology it could be demonstrated that the Warmblood stud had been harbouring EAV for a longer period of time. Likewise, the Lipizzaner stud could be shown to have been persistently infected, this time on pre-abortion serums stored frozen at our Institute. On both these studs preexisting neutralizing antibodies accounted for the single case of abortion and prevented serial abortions. By investigating frozen serums taken in earlier years we could show that the Lipizzaner stallions had reacted positively to EAV for several years already. However, the gestation period of the aborting mare allowed to exclude EAV-positive semen transmitted on copulation as cause of its abortion. Both the Iceland Pony stallion as well as the Warmblood stallion could be excluded as sources of infection for the respective aborting mares as both repeatedly were seronegative.(ABSTRACT TRUNCATED AT 250 WORDS)

Equine arteritis virus: an overview

The causative agent of the respiratory disease equine viral arteritis is a small, single-stranded RNA virus with a genome organization and replication strategy related to that of coronaviruses and toroviruses. Clinical signs of infection in horses vary widely and severe infection can lead to pregnant mares aborting. Infected horses generally make good recoveries but stallions may become semen shedders of equine arteritis virus (EAV). These carrier stallions play an important role in the dissemination and perpetuation of EAV. Laboratory tests exist to detect virus and the equine immune response to infection. However, vaccines are not currently licensed in the UK to combat viral arteritis, the incidence of which may increase due to changes in European legislation.

Polyarteritis associated with Yersinia enterocolitica infection

A patient developed polyarteritis, predominantly affecting the muscles, 10 days after a Yersinia enterocolitica O:3 infection. Immunoperoxidase staining showed Yersinia enterocolitica O:3 antigen in the subendothelial layer of the blood vessels. This suggests that vasculitis should be considered as a rare manifestation of Yersinia enterocolitica infection.

Human pythiosis in Srinagarind Hospital: one year's experience

We have reported four cases of human pythiosis arteritis from Srinagarind Hospital, Khon Kaen, Thailand. This unusual human infection occurring perhaps exclusively in thalassemia and hemoglobinopathy patients, should be noted by physicians, who work in areas with a high incidence of hemoglobinopathy, and for patients who present with unexplained arterial insufficiency. As our reported cases occurred within only one year, this condition may be more common than originally suspected and found more frequently if actively searched for.