Endocarditis por Aspergillus fumigatus en válvula nativa con hemocultivo positivo y galactomanano negativo. Descripción de un caso y revisión de la literatura

Native valve endocarditis caused by Aspergillus spp. is an uncommon disease with a high mortality rate. Generally, Aspergillus is isolated from affected valve in post-mortem or biopsy specimens. However, its isolation from blood cultures is exceedingly rare. We report a case of fungal endocarditis in a native mitral valve with the isolation of Aspergillus fumigatus both in valve vegetation and in blood culture bottles. The patient underwent valve replacement and antifungal treatment with voriconazole and caspofungin, but he died on post-operative day 45 with disseminated aspergillosis confirmed by necropsy. Paradoxically, galactomannan antigen detection in serum was negative. This is the third case of Aspergillus endocarditis with positive blood culture reported in the literature.

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.

Mycotic aneurysm of the renal transplant artery

A case of mycotic aneurysm secondary to septicemia is reported. A 59-year-old man with end-stage renal failure underwent renal transplantation from a living donor. On the fifteenth postoperative day, he was febrile and his arm around an entry wound of the drip infusion had infectious signs. Cultures of the blood and pus discharge grew Methicillin-resistant Staphylococcus aureus. Vancomycin was administered intravenously for 30 days. Then the existence of a mycotic aneurysm on the transplant artery was not suspected by computed tomography. After his infectious signs disappeared, examinations revealed a pseudoaneurysm measuring 4 cm in diameter at the site of anastomosis between the renal transplant and external iliac arteries by computed tomography. He has been carefully followed up with a conservative management. This is the first case of a mycotic aneurysm treated conservatively and displaying an uneventful course without rupture.

Infected Aortic Aneurysms: Imaging Findings

PURPOSE

To determine the imaging characteristics of infected aortic aneurysms.

MATERIALS AND METHODS

Review of records of patients with surgical and/or microbiologic proof of infected aortic aneurysm obtained over a 25-year period revealed 31 aneurysms in 29 patients. This study included 21 men and eight women (mean age, 70 years). One radiologist reviewed 28 computed tomographic (CT) studies (22 patients underwent CT once and three patients underwent CT twice), 12 arteriograms (12 patients underwent arteriography once), eight nuclear medicine studies (six patients underwent nuclear medicine imaging once and one patient underwent nuclear medicine imaging twice), and three magnetic resonance (MR) studies (three patients underwent MR imaging once). Features evaluated included aneurysm size, shape, and location; branch involvement; aortic wall calcification; gas; radiotracer uptake on nuclear medicine studies; and periaortic and associated findings. The location of infected aortic aneurysms was compared with that of arteriosclerotic aneurysms.

RESULTS

Aneurysms were located in the ascending aorta (n = 2, 6%), descending thoracic aorta (n = 7, 23%), thoracoabdominal aorta (n = 6, 19%), paravisceral aorta (n = 2, 6%), juxtarenal aorta (n = 3, 10%), infrarenal aorta (n = 10, 32%), and renal artery (n = 1, 3%). Two patients had two infected aortic aneurysms. CT revealed 25 saccular (93%) and two fusiform (7%) aneurysms with a mean diameter at initial discovery of 5.4 cm (range, 1-11 cm). Paraaortic soft-tissue mass, stranding, and/or fluid was present in 13 (48%) of 27 aneurysms, and early periaortic edema with rapid aneurysm progression and development was present in three (100%) patients with sequential studies. Other findings included adjacent vertebral body destruction with psoas muscle abscess (n = 1, 4%), kidney infarct (n = 1, 4%), absence of calcification in the aortic wall (n = 2, 7%), and periaortic gas (n = 2, 7%). Angiography showed 13 saccular aneurysms with lobulated contour in 10 (77%). Nuclear medicine imaging showed increased activity consistent with infection in six (86%) of seven aneurysms. MR imaging showed three saccular aneurysms. Adjacent abnormal vertebral body marrow signal intensity was seen in one (33%) of three patients.

CONCLUSION

Saccular aneurysms (especially those with lobulated contour) with rapid expansion or development and adjacent mass, stranding, and/or fluid in an unusual location are highly suspicious for an infected aneurysm.

Pseudoaneurysm of the iliac artery secondary to Aspergillus infection in two recipients of kidney transplants from the same donor

The authors report 2 cases of patients who underwent cadaveric renal transplantation from the same donor in a multiorgan extraction procedure. Both cases showed, during the first 6 months posttransplantation, a worsening in renal graft function and signs of ischemia in the homolateral lower limb. One of the cases was preceded by pain in the sciatic region. In imaging tests, a pseudoaneurysm was detected in the iliac artery in both patients. Grafts had to be removed, and the iliac arteries were ligated with posterior isolation of Aspergillus spp from the arterial vessels but not from the renal tissue. Besides surgery, medical treatment with liposomal amphotericin B was initiated with a different outcome in each patient: patient A died, whereas patient B recovered. The absence of Aspergillus spp infection in liver and heart recipients ruled out a donor-transmitted infection. The graft placements were carried out in different operating rooms, which rules out contamination during the transplantation process. All of this leads us to conclude that the infection must have occurred during the preservation phase of the kidney.

Demonstration of Chlamydia pneumoniae in atherosclerotic arteries from various vascular regions

Chlamydia pneumoniae (CP) has been reported to be a pathogenic agent in the mechanism leading to atherosclerosis. The majority of available data is focused mainly on coronary artery disease whereas the distribution of CP in different areas, associated with atherosclerotic disorders, has not been completely clarified. In this study we investigated the presence of CP in atheromasic plaques from five different vascular areas (basilary artery, coronary artery, thoracic aorta, abdominal aorta, renal arteries) using nested polymerase chain reaction (PCR) and immunohistochemical staining (IHC), in order to establish the putative association of CP with atherosclerotic disease. The same atheromasic plaques were also tested for the presence of Helicobacter pylori (HP) and cytomegalovirus (CMV), other putative agents of atherosclerosis, using a nested PCR technique. Our data indicate that the presence of CP can be demonstrated in 100% of patients tested, considering globally the five areas of analysis. On the other hand the presence of HP has been demonstrated in four out of 18 patients (22.2%), and CMV only in three out of 18 (16.6%). Our results strongly suggest an association between CP and atherosclerosis and highlight the need for the detection of CP in multiple vascular areas of the same patient.

"True" mycotic aneurysm of a renal artery allograft

A 60-year-old white man sustained a rupture of the renal artery 6 weeks after a cadaveric kidney transplantation. The bleeding site was repaired, and culture of the hematoma showed an isolated growth of Candida albicans. Blood and urine cultures were negative. Systemic antifungal therapy was initiated. Bleeding from the renal artery recurred, eventually requiring removal of the transplanted kidney. Histopathology of the resected specimen showed budding yeast in the wall of the renal artery, but no evidence of fungal invasion of the kidney. The patient received 6 weeks of amphotericin B therapy and currently remains on hemodialysis therapy.

Absence of association between cytomegalovirus infection and obliterative transplant arteriopathy in renal allograft rejection

Cytomegalovirus (CMV) was recently identified, using in situ hybridization, in the coronary arteries of patients with cardiac transplant rejection, suggesting a role of CMV in the development of obliterative transplant arteriopathy in cardiac allografts. We sought to verify this observation by examining arteries in kidney transplants with intimal thickening due to chronic rejection. Eleven renal biopsies and 13 nephrectomies from 24 patients, all showing obliterative transplant arteriopathy, were collected for this study. Of these patients, six were seropositive for CMV before transplantation, three were identified as seropositive following renal transplantation, nine had no evidence of CMV infection, and clinical data were not available for an additional six patients. Paraffin-embedded renal sections were examined for the presence of CMV by immunohistochemistry in situ hybridization and polymerase chain reaction. By these methods, only one case (1/24) was demonstrated to have CMV infected cells in the renal interstitium, tubules, and glomeruli, but none (0/24) showed CMV to be located in any of the renal arteries or arterioles. Thus, our results suggest that obliterative transplant arteriopathy can occur in the absence of demonstrable CMV and is probably unrelated to direct CMV infection of the graft.

Secondary haemorrhage from the arterial anastomosis of renal allografts

Four cases of massive secondary haemorrhage from the arterial anastomosis of a renal allograft as a result of infection are described.

It is likely that the infections developed in the donors and that careful selection is necessary to prevent this. Immediate allograft nephrectomy is suggested as the treatment of choice. The external iliac artery may be ligated without necessarily embarrassing the circulation to the leg.