Analysis of the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft infection.

BACKGROUND: As a result of constantly improving surgical methods, an increasing number of patients have medical devices implanted in the cardiovascular system (including vascular grafts and endografts). Such patients are characterised by their high risk of infectious complications due to the possibility of biofilm formation on implanted material. This work aims to analyse the utility of 2-[18F]FDG PET/CT in diagnosing vascular graft and endograft infections. MATERIAL AND METHODS: The study was undertaken on a group of 58 patients, of whom 34 were in the study group, and 24 were in the control group. The 2-[18F]FDG PET/CT study was conducted in the Nuclear Medicine Department at the University Hospital of Lublin. The inclusion criteria for the study group were the presence of a vascular graft or endograft that encompasses the aorta, and strong clinical suspicion of its infection. The inclusion criteria for the control group were the presence of a vascular graft or endograft in the large arteries and the absence of signs of its infection on 2-[18F]FDG PET/CT, as well as the absence of clinically apparent signs and symptoms during six months of observation after 2-[18F]FDG PET/CT. All patients found in the database that met the criteria were included. RESULTS: Vascular endografts were more common in the control group than in the study group. However, in the case of infection of the vascular endograft, signs of infection in 2-[18F]FDG PET/CT were more severe. Images in the study group were divided into three groups that represent image patterns based on CT and PET characteristics. The first pattern (P1) was recognised in six patients. The second (P2) and third (P3) were visible in 11 and 17 patients, respectively. CONCLUSIONS: Comparative analysis of the study and control groups demonstrates the utility of 2-[18F]FDG PET/CT in the diagnosis of vascular graft/endograft infection.

Patterns of vascular graft infection in 18F-FDG PET/CT.

BACKGROUND: 18F-FDG PET/CT has become an important tool in diagnosis of prosthetic vascular graft infections (PVGI). The aim of the study was to identify the patterns of vascular graft infection in 18F-FDG PET/CT. MATERIAL AND METHODS: The study was performed in 24 patients with vascular graft infection, in 17 patients implanted in an open surgery mode and in 7 patients by endovascular aortic repair (EVAR). Vascular prostheses were evaluated by two visual scales and semi-quantitative analysis with maximum standardized uptake values (SUV max). RESULTS: In the 3-point scale: 23 patients were in grade 1 and one patient was in grade 2. In the 5-point scale: 19 patients were in grade 5 with the highest activity in the focal area, 4 patients were in grade 4 and one patient in grade 3. The visual evaluation of 18F-FDG PET/CT study revealed that peri-graft high metabolic activity was associated with occurrence of morphological abnormalities (n = 21) like gas bubbles and peri-graft fluid retention or without abnormal CT findings (n = 3). The presence of the gas bubbles was linked to higher uptake of 18F-FDG (p < 0.01, SUVmax 11.81 ± 4.35 vs 7.36 ± 2.80, 15 vs 9 pts). In EVAR procedure, the highest metabolic activity was greater than in classical prosthesis (SUVmax 21.5 vs 13). CONCLUSIONS: 18F-FDG PET/CT is a very useful tool for assessment of vascular graft infections. CT findings like gas bubbles, or peri-graft fluid retention were associated with significantly higher glucose metabolism; however, in some cases without anatomic alterations, increased metabolic activity was the only sign of infection.

Replacement of infected aortoiliac vascular grafts with bifurcated BioIntegral Surgical No-React® bovine pericardial xenografts.

The infection of a vascular prosthesis is potentially fatal, and its effective treatment still remains the greatest challenge for vascular surgeons. We present our initial experience using bovine pericardial vascular prostheses to replace infected aortoiliac vascular grafts. Six consecutive patients with infection of the graft were prospectively included in this study. Infection of the vascular graft was confirmed by clinical symptoms, laboratory tests and the results of computed tomography and positron emission tomography/computed tomography. In all cases, the infected aortoiliac graft was surgically removed and replaced by the bovine-pericardial BioIntegral aortic-bifemoral prosthesis. Technical success was achieved in every case with no in-hospital or 30 days mortality. One patient required revision of distal anastomosis due to recurrent bleeding at day four after surgery. One patient presented with upper gastrointestinal tract bleeding during the postoperative period, which was managed endoscopically. The mean hospital stay was 14 days (range 9-19). The control CT scan performed 2 months after surgery showed significant regression of abscesses and periprosthetic inflammation. Two patients died within 32 months of follow-up: one due to heart attack, the other due to generalized sepsis, which was correlated with the previous infection. Four patients are still in follow-up. The BioIntegral prosthesis is patent in all four cases, with no clinical or ultrasonographic signs of infection. Our brief investigation shows that a bovine pericardial prosthesis may be a valuable option in the treatment of vascular grafts infections.

Role of 18F-FDG PET/CT in the diagnosis of inflammatory and infectious vascular disease.

This review article discusses the utility of 18F-FDG PET/CT in diagnosis and management of vascular disease. We stress usefulness of this method in large vessel inflammation and infection. In our work we based on the literature analysis and clinical cases diagnosed in our institution by use of 18F-FDG PET/CT. The literature exploration was focusing on vascular inflammation and infections and 18-FDG PET. The search was performed on PubMed database and cross referencing. We present the practical review with several images of vascular diseases like: Takayasu arteritis, giant cell arteritis, vascular graft infections, abdominal aortic aneurysm infections and cases of aortitis and periaortitis. From this work inflammation associated with atheromatic process and vulnerable atherosclerotic plaque we excluded. 18F-FGD PET/CT is a sensitive metabolic, reliable, non-invasive imaging modality suitable for diagnosis and follow-up of inflammation and infections in vascular system.

The role of apolipoprotein (a) in pathogenesis and clinical course of deep venous thrombosis.

UNLABELLED: Deep venous thrombosis is widespread disease, which complications, like: pulmonary embolism and postphlebitis syndrome areimportant social problem. There are many well-known and accurately described risk factors, though in many cases etiology remains unexplained. Further research into causes of deep venous thrombosis seem to be fully justified. The aim of the study was the evaluation of the influence of apolipoprotein (a) serum level in patients with deep venous thrombosis and the changes of its concentration during the treatment. MATERIALS AND METHODS: 26 patients with newly diagnosed deep venous thrombosis (DVT) were enrolled to the study. Diagnosis of DVT was established by use of physical examination and duplex Doppler. Measurements of apolipoprotein (a) and D-dimers serum level were recorded on the following days, starting from the day of the initial diagnosis: 1, 7, 14 and 84. RESULTS: Statistically significant increase of the level of serum apolipoprotein (a) has been found during properly conducted treatment. CONCLUSIONS: Alterations of the concentration of serum apoliprotein (a) during the deep venous thrombosis treatment, indicates the involvement of apolipoprotein (a) in pathogenesis of deep venous thrombosis.

Assessment of plasma prothrombotic factors in patients with Buerger's disease.

The pathogenesis of Buerger' disease (thrombangiitis obliterans; TAO) remains unknown, although a strong association with tobacco use has been established. Blood coagulation and fibrinolytic factors as well as selected clinical chemistry parameters have been evaluated in 37 patients with Buerger's disease. Median levels of prothrombotic factors were higher in patients with TAO than in healthy control: annexin V (P < 0.0003), factor VII (P < 0.0001), factor VIII (P < 0.0000001), factor XI (P < 0.000003), homocysteine (P < 0.014) and fibrinogen (P = 0.00007). Patients with Buerger's disease also showed higher median plasma levels of urokinase type plasminogen activator (uPA) (P < 0.000004), its receptor (uPAR) (P < 0.0008) and uPA complex with plasminogen activator inhibitor 1 (uPA-PAI-1) P < 0.000006). In contrast, plasma concentrations of apolipoprotein A and folic acid were lower in patients with TAO than in control (P < 0.004 and P < 0.0006; respectively). Higher plasminogen (P < 0.05) and cholesterol (P < 0.003), as well as lower folic acid (P < .0.05) levels were noted in the smokers group than in nonsmoking patients. We found higher plasminogen (P < 0.05), factor VII (P < 0.05), total lipids (P < 0.003), cholesterol (P < 0.05) and triglycerides (P < 0.002) levels in patients requiring surgical treatment for limb-threatening ischaemia than the patients treated only conservatively. These findings suggest an important role of haemostatic risk factors in the pathogenesis of Buerger's disease, with special regard to hyperhomocysteinemia that might be aggravated by low serum folic acid level. In patients with aggressive clinical course, disturbances in serum lipids were more pronounced. Further studies are warranted to establish whether diet supplementation of folic acid as well as normalization of lipids balance might influence the clinical course of TAO.