Diagnosis Of Vascular Graft Infection Research Articles

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

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. 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. 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. 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.

Infections associated with vascular reconstruction procedures at the Department of Surgery in Pilsen in retrospect

Vascular graft infection is a rare but serious complication in vascular surgery, associated with high morbidity and mortality. Early diagnosis of vascular graft infection is important for proper and timely surgical and antibiotic treatment that improves the outcome. The tactic and techniques of surgical treatment of vascular graft infection have changed over the last two decades, and this trend can also be observed in our retrospective study. We evaluated a group of patients with prosthetic vascular reconstructions performed at the Department of Surgery, University Hospital in Pilsen in the period of 2003-2021 using retrospective analysis. In the analyzed 19-year period, 23 infected vascular grafts were managed out of a total of 2090 performed peripheral bypasses, and 27 infected vascular grafts were managed out of a total set of 1940 central reconstructions. The incidence of peripheral vascular graft infections at our Department of Surgery in the period of 2003-2021 reached 1.1% with the early mortality rate of 8.7%; 1.4% central vascular graft infections occurred in the same time period with 33% early mortality. The results of our retrospective study are comparable virtually in all parameters with the experience of other departments. Consistently, our department switched to in situ replacements for explanted vascular grafts and we can confirm good experience with silver impregnated grafts.

18F-fluorodeoxyglucose PET/CT in the diagnosis of vascular graft infection

To investigate diagnostic role of 18F-fluorodeoxyglucose PET/CT in patients with suspected vascular graft (VG) infection. A prospective analysis included data of 30 PET/CT examinations for suspected infection of aortic VG (n=27) and bypass grafts (n=3) after surgical treatment (median 48 months). In 77% (23/30) of cases, the diagnosis was initially «possible» (n=11) or «rejected» (n=12) in accordance with common diagnostic criteria. All PET/CT results were verified by clinical, laboratory and intraoperative («=20) data. VG infection was confirmed in 18 patients and ruled out in 12 cases. PET/CT confirmed VG infection in 94% (17/18) and excluded in 50% (6/12) of cases. False PET/CT results were obtained in 23% (7/30) cases: false positive in 6 cases and false negative in 1 case. Thus, sensitivity, specificity and diagnostic accuracy of PET/CT were 94%, 50% and 77%, respectively; positive and negative predictive value - 74% and 86%. PET/CT results allowed correct reclassifying 33% (10/30) of cases. VG infection was confirmed in 73% (8/11) of patients with initially «possible» diagnosis and excluded in 17% (2/12) of patients with initially «rejected» infection. Moreover, whole body PET/CT revealed unknown inflammation foci outside VG in 73% (22/30) of cases. These data were applied to correct treatment approach in 80% (24/30) of cases. Our results showed high efficacy of 18F-fluorodeoxyglucose PET/CT in the diagnosis of VG infection. Despite low specificity, this technique has high sensitivity and accuracy that allowed reclassifying 33% of cases.

99mTC-white blood cell scintigraphy with SPECT/CT in the diagnosis of vascular graft infection

AimVascular graft infection is a rare complication with a high morbidity and mortality. Early diagnosis is essential to establish an adequate treatment. We assess the accuracy of 99mTc-WBC scintigraphy with SPECT/CT in the diagnosis of vascular graft infection. Materials and methodsWe retrospectively analyzed thirty 99mTc-WBC scintigraphies with SPECT/CT performed in thirty patients with suspicion of vascular prosthesis infection. Studies were considered positive for graft infection if the intensity of activity involving the graft was greater than the liver or bone marrow activity (spine and pelvis). ResultsFinal diagnosis of infection was established in 10 patients, based on Fitzgerald criteria. Scintigraphy was positive in 11 patients. No false negatives were obtained. The values of sensitivity and specificity were 100% and 95% respectively, with a PPV of 91% and a NPV of 100%.25 patients had a CT performed prior to scintigraphy, in 9 cases the result was positive and in the remaining 16 was negative. CT sensitivity and specificity obtained in our study were 62.5% and 76% respectively, with a PPV of 55.6% and a NPV of 81.3%.Diagnosis of infection led to prosthesis exeresis in 8 cases (all of them had a positive microbiological study of the extracted material), while the remaining 2 patients were treated with antibiotic therapy alone due to high surgical risk. ConclusionOur results suggest a high accuracy for 99mTc-WBC scintigraphy with SPECT/CT in the assessment of clinically suspected arterial graft infection.

Gammagrafía con leucocitos marcados y SPECT/TC en el diagnóstico de infección de prótesis vasculares

AimVascular graft infection is a rare complication with a high morbidity and mortality. Early diagnosis is essential to establish an adequate treatment. We assess the accuracy of 99mTc-WBC scintigraphy with SPECT/CT in the diagnosis of vascular graft infection. Materials and methodsWe retrospectively analyzed thirty 99mTc-WBC scintigraphies with SPECT/CT performed in thirty patients with suspicion of vascular prosthesis infection. Studies were considered positive for graft infection if the intensity of activity involving the graft was greater than the liver or bone marrow activity (spine and pelvis). ResultsFinal diagnosis of infection was established in 10 patients, based on Fitzgerald criteria. Scintigraphy was positive in 11 patients. No false negatives were obtained. The values of sensitivity and specificity were 100% and 95%, respectively, with a PPV of 91% and a NPV of 100%.Twenty five patients had a CT performed prior to scintigraphy, in 9 cases the result was positive and in the remaining 16 was negative. CT sensitivity and specificity obtained in our study were 62.5% and 76% respectively, with a PPV of 55.6% and a NPV of 81.3%.Diagnosis of infection led to prosthesis exeresis in 8 cases (all of them had a positive microbiological study of the extracted material), while the remaining 2 patients were treated with antibiotic therapy alone due to high surgical risk. ConclusionOur results suggest a high accuracy for 99mTc-WBC scintigraphy with SPECT/CT in the assessment of clinically suspected arterial graft infection.

Imaging Modalities for the Diagnosis of Vascular Graft Infections: A Consensus Paper amongst Different Specialists.

Vascular graft infection (VGI) is a rare but severe complication of vascular surgery that is associated with a bad prognosis and high mortality rate. An accurate and prompt identification of the infection and its extent is crucial for the correct management of the patient. However, standardized diagnostic algorithms and a univocal consensus on the best strategy to reach a diagnosis still do not exist. This review aims to summarize different radiological and Nuclear Medicine (NM) modalities commonly adopted for the imaging of VGI. Moreover, we attempt to provide evidence-based answers to several practical questions raised by clinicians and surgeons when they approach imaging in order to plan the most appropriate radiological or NM examination for their patients.

Diagnostic yield of 18F-FDG PET/CT in suspected diagnosis of vascular graft infection: A prospective cohort study

BackgroundProsthetic vascular graft infection (PVGI) is a severe complication associated with high morbidity and mortality. Clinical diagnosis is complex, requiring image testing such as CT angiography or leukocyte scintigraphy, which has considerable limitations. The aim of this study was to know the diagnostic yield of PET/CT with 18F-Fluorodeoxyglucose (18F-FDG) in patients with suspected PVGI. MethodsWe performed a prospective cohort study including 49 patients with suspected PVGI, median age of 62 ± 14 years. Three uptake patterns were defined following published recommendations: (i) focal, (ii) patched (PVGI criteria), and (iii) diffuse (no PVGI criterion). ResultsSensitivity, specificity, and positive and negative predictive values for 18F-FDG-PET/CT were 88%, 79%, 67%, and 93%, respectively. 18F-FDG-PET/CT identified 14/16 cases of PVGI showing a focal (n = 10) or patched pattern (n = 4), being true negative in 26/33 cases with either a diffuse pattern (n = 16) or without uptake (n = 10). Five of the seven false-positive cases (71%) showed a patched pattern and all coincided with the application of adhesives for PVG placement. Conclusions18F-FDG-PET/CT is a useful technique for the diagnosis of PVGI. A patched pattern on PET/CT in patients in whom adhesives were applied for prosthetic vascular graft placement does not indicate infection.

Accuracy of PET/CT in the Diagnosis of Vascular Graft Infections

Introduction - Vascular graft infections (VGI) have an incidence of 1 to 6 %. Positron emission tomography/computed tomography with 18F-fluorodeoxyglucose (FDG-PET/CT) has emerged as a new tool to replace nuclear scintigraphy. However, its clinical reliability is still unknown. The aim of this study was to evaluate the diagnostic accuracy of FDG-PET/CT in a population with suspected VGI and to validate the quantitative value of diagnostic parameters. Methods - This is a retrospective cohort study. FDG-PET/CT was performed in 37 patients with suspected VGI between 2013 and 2017. A reliable culture was obtained in 25 of them and were finally included in the study. VGI was considered proven only in case of a positive culture (blood, peri-graft collections or graft samples. Diagnostic accuracy was assessed comparing culture results (gold standard) with FDG-PET/CT values. We assessed maximal standardized uptake value (SUVmax), tissue-to-background ratio (TBR), and visual parameters (FDG distribution patterns and visual grading scale) in the final confirmation of the diagnosis of AGI. Receiver operating characteristics (ROC) curves were used to assess the ability of SUVmax and TBR to identify the presence and absence of VGI. Results - The mean age was 64.32 ± 16.75 years, 72% were males. Cultures were positive in 20/25 patients. FDG-PET/CT was considered positive in 19/25 patients. Surgery was performed in 13/25 patients. Mortality was 24% (6/25 patients). The most frequent microorganism was Staphylococcus aureus (9/13 patients). All these patients were followed with long-term antibiotic treatment until negativization of tests including FDG-PET / CT. Mean SUVmax was 6.4 ± 3.41 and TBR 2.14 ± 0.5 in all cases. For positives cultures the mean SUVmax was 7.34 ± 3.3 with a TBR 3.73 ±1.7. In the ROC analysis, the area under the curve for SUVmax was 0.56 (95% CI: 0.30-0.84) and for TBR was 0.53 (95% CI:0.27-0.78). A SUVmax cut off point of 4.5 yielded a 91,7% Sensitivity (Sens) and 50% Specificity (Spec). A TBR cut off point of 2.9 yielded 58% Sens and a 60% Spec with a positive predictive value of 73.68% and negative predictive value of 83.33%. Conclusion - FDG-PET/CT may be a useful tool in the diagnosis and surveillance of VGI. Nevertheless, the accuracy of quantitative parameters is jeopardized by the uncertainty of gold standard based on microbiology data. Further and larger registers with standardized measurements are needed to establish a more reliably parameters, necessary to take difficult decisions in this kind of patients. References-Sah BR, Husmann L, Mayer D, Scherrer A, Rancic Z, Puippe G, Weber R, Hasse B; VASGRA Cohort. Diagnostic performance of 18F-FDG-PET/CT in vascular graft infections. Eur J Vasc Endovasc Surg. 2015 Apr;49(4):455-64.-Saleem BR, Berger P, Vaartjes I, de Keizer B, Vonken EJ, Slart RH, de Borst GJ, Zeebregts CJ. Modest utility of quantitative measures in (18)F-fluorodeoxyglucose positron emission tomography scanning for the diagnosis of aortic prosthetic graft infection. J Vasc Surg. 2015 Apr;61(4):965-71.

Conventional culture diagnostics vs. multiplex PCR for the detection of causative agents of vascular graft infections - results of a single centre observational pilot study.

Background: Timely diagnosis of vascular graft infections is of major importance in vascular surgery. The detection of causative microorganisms is needed for specific medical treatment, but conventional culture is often slow, insensitive and inconclusive due to antibiotic pre-treatment. Detection of bacterial DNA by polymerase chain reaction (PCR) might bypass these problems. We hypothesised that multiplex PCR (mPCR) is feasible, fast and sensitive to detect causative microorganisms in vascular graft infections. Patients and methods: We performed a pilot observational prospective study comparing conventional culture and a commercial mPCR. Inclusion criteria were: confirmed graft infection, suspicious imaging, clinical suspicion, anastomotic aneurysm and repeated graft occlusion. Diagnostic methods were performed using identical samples. Time to result, microorganisms and antibiotic resistance in both groups were compared using Student's t-test or nonparametric tests. Results: 22 samples from 13 patients were assessed and 11 samples were negative for bacteria. Some showed multiple germs. In total, we found 15 different organisms. 13 samples matched, 9 had non-concordant results. Out of the mismatches 3 microorganisms identified in PCR were not detected by culture. Time to result with PCR was shorter (median 5h vs. 72h, p<0.001) than with culture. No resistance genes were detected by mPCR, but conventional culture allowed susceptibility testing and revealed resistance in 5 samples. Conclusions: mPCR seems to be a feasible and quick tool to detect causes of vascular graft infections within 24h and might be helpful in antibiotic pre-treated patients. The detection of antibiotic resistance with mPCR needs improvement for clinical practice.

Comparison of Genus Specific PCR and Culture with or without Sonication for Microbiological Diagnosis of Vascular Graft Infection

Vascular graft infections (VGIs) are severe and require prolonged adequate antimicrobial therapy. However, up to 45% of conventional cultures are negative. Sonication and genus specific PCRs for microbiological diagnosis of VGI was evaluated. Samples were prospectively obtained from explanted vascular grafts in Bordeaux University Hospital. Conventional bacterial cultures with and without prior sonication of samples were performed. A genus specific PCR assay panel, targeting the most frequent bacteria involved in VGI (Staphylococcus, Streptococcus, Enterococcus, and Enterobacteriaceae), was also applied to sonicate fluids. The performance of these three diagnostic strategies was compared. Forty-five patients (118 samples) were included between July 2014 and October 2015. Six patients had no infection and 39 had a VGI. Sensitivities of graft culture, sonicate fluid culture, and genus specific PCR were 85.7%, 89.7%, and 79.5%, respectively. Specificities were 100%, 100%, and 83.3%, respectively. Sonicate fluid culture was positive for five graft samples (from four patients) with negative culture without sonication. Four VGIs were detected by PCR only (3 patients had previously received antibiotics). For 15 patients with positive graft cultures, PCR identified at least one additional bacterium compared with culture, thus 30 additional bacteria for all included patients. By combining sonicate fluid culture and PCR, a microbiological diagnosis was obtained for all patients with VGI. There was no statistical difference between performances of culture with and without sonication and genus specific PCR. However, combining sonicate fluid cultures and PCR may be the best strategy for microbiological diagnostic of VGI.

The Clinical Usefulness of Nuclear Medicine Techniques in the Diagnosis of Vascular Graft Infections

The infection of a vascular prosthesis (VGI) is the most serious complication in prosthetic vascular reconstructive surgery, burdened by a high rate of mortality and morbidity. The treatment of a VGI, in most cases, consists of its surgical removal, and therefore an accurate diagnosis of the infection, is of paramount importance in clinical practice since false-positive results may lead to unnecessary major surgery whereas false-negative results are related with high-risk morbidity. Furthermore, early diagnosis of infection permits a wider range of therapeutic options and a less aggressive surgical approach. On the basis of the documents and abstracts published in the last 25 years, the authors analyze and discuss the contribution of nuclear medicine in the management of these infections, evaluating the reliability of scintigraphy with labeled leukocytes, other gamma-emitting radiopharmaceuticals, PET and PET / CT with 18F-Fluorodeoxiglucose. Keywords: 18F-FDG, 99mTc-labelled leucocytes, imaging, PET / CT, SPECT / CT, vascular graft infection.

Prosthetic vascular graft infections: A center experience

IntroductionProsthetic graft infection is a major complication of vascular surgery associated with high morbid-mortality rates. This retrospective non-randomized single center study evaluated our experience in the management of prosthetic vascular graft infections. MethodsWe review the clinical files of patients who had vascular grafts implanted at our center between June 2007 and December 2011 and analysed the cases that developed Samson group 3, 4 and 5 infections until December 2012. ResultsFrom June 2007 to December 2012, 18 consecutive patients (14 males, 4 females) with median age 70 years were admitted to our institution with the diagnosis of vascular graft infection accounting for an incidence of 3.8%. 50% of these infections were early infections and MRSA was the most prevalent pathogen. 44% of infections were due to infection of a femoro-popliteal bypass. Using Samson classification, 72% were group 4 and 5 infections. We performed graft preservation in one patient, graft excision without revascularization in 50% (nine) patients; Excision + insitu replacement in 39% (seven) patients; Excision + Extra-anatomic bypass in one patient. Our amputation rate was 55% and our related death rate was 16%. ConclusionsOur amputation and mortality rates are according the published reviews. Besides allowing recognition of our reality this offers the opportunity to review diagnosis and therapeutic issues in prosthetic vascular graft infections. Each situation needs to be individualized as there is no consensus nor guiding algorithms about what should be the best medical treatment.

18 F-FDG-PET CT Scan: Future Gold Standard in Diagnosis of Vascular Graft Infection?

18 F-FDG-PET CT Scan: Future Gold Standard in Diagnosis of Vascular Graft Infection?

Ascending Aortic Graft Thrombosis and Diffuse Embolization From Early Endoluminal Aspergillus Infection

We present a 43-year-old man who underwent emergent replacement of the ascending aorta for type A dissection and hemiarch reconstruction with a 28-mm prosthetic graft. Dramatic neurologic symptoms, renal failure, and bowel ischemia developed on postoperative day 5. A computed tomography scan showed a large floating thrombus in the ascending aortic graft and massive peripheral embolization throughout the body.

Relevance of the positron emission tomography in the diagnosis of vascular graft infection with Coxiella burnetii

Coxiella burnetii, the causative agent of Q fever, may cause culture-negative vascular graft infections that can be diagnosed by serology and molecular biology. We present a case of vascular graft infection detected by positron emission tomography (PET) scanner. The presence of C. burnetii was confirmed by high antibody titers and positive polymerase chain reaction specific for C. burnetii. This report emphasizes the relevance of the PET scanner in the diagnosis of infection when used in association with Q fever serology and molecular biology for the etiological identification of C. burnetii.

Comparison of detection of F-18 fluorodeoxyglucose positron emission tomography and 99mTc-hexamethylpropylene amine oxime labelled leukocyte scintigraphy for an aortic graft infection☆

To compare F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG-PET) and (99m)Tc-hexamethylpropylene amine oxime ((99m)TC-HMPAO) labelled leukocyte scintigraphy for the diagnosis of vascular graft infection. A thoraco-abdominal CT-angiography and a (99m)TC-HMPAO labelled leukocyte scintigraphy did not show any graft infection in this case report whereas an F-18 FDG-PET showed a metabolic uptake around and all along the vascular graft. Further comparison between these two explorations is needed since the two techniques have not been compared in vascular graft infection.

18F-FDG PET-CT for diagnosis of vascular graft infection: midterm results

18F-FDG PET-CT for diagnosis of vascular graft infection: midterm results

The Use of Positron Emission Tomography With (18)F-Fluorodeoxyglucose for the Diagnosis of Vascular Graft Infection

Vascular graft infection is associated with a high morbidity and mortality rate. Diagnosis is difficult, as there is no single diagnostic criterion that has a 100% accuracy. A combination of physical examination, laboratory tests, and several imaging techniques is mandatory. Beside a wide range of indications in the oncological field, positron emission tomography with (18)F-fluorodeoxyglucose (FDG-PET) has a well-known role in the diagnosis of bone and soft-tissue infections. Some authors have recently reported on the potential use of FDG-PET in the diagnosis of vascular graft infections. The aim of this study is to review personal experience. Five consecutive patients with a suspected prosthetic infection (1 aortobifemoral bypass, 3 femoropopliteal bypasses, and 1 femorofemoral bypass) underwent FDG-PET. All prostheses showed a moderate or intense FDG tracer uptake. All 3 patients with an intense FDG uptake proved to have a prosthetic infection (based on microbiologic examination). These preliminary results suggest that FDG-PET might be an interesting tool to confirm vascular graft infection.

Detection of Abdominal Aortic Graft Infection: Comparison of Magnetic Resonance Imaging and Indium-Labeled White Blood Cell Scanning

Infected abdominal aortic grafts rank as one of the most severe complications of vascular surgery, with high mortality and morbidity. The incidence of infection after prosthetic aortic reconstruction is 1-3%. Diagnosis of vascular graft infection can be occasionally difficult. Clinical manifestations and assessment of the extent of graft infection are usually nonspecific, and their detection by radiographic methods, such as computed tomography (CT), magnetic resonance imaging (MRI), and leukocyte -imaging, can be difficult. The purpose of this study was to evaluate the predictive value (PV) of indium-111-labeled white blood cell scanning (WBCS) and MRI in patients who were suspected of having intracavitary vascular graft infection (IGF). The study was done as a cross-control retrospective, single-center study. Fifty-eight In-111-labeled WBC scans and 59 MRIs were performed in suspected patients between January 1995 and January 2005. Among the 40 suspected patients, 35 cases of aorta graft infection were identified intraoperatively. The diagnosis of IGF was based on clinical signs, microbiological and histological examination, MRI and leukocyte imaging, and lack of graft incorporation with surrounding fluid observed intraoperatively. The positive PV (PPV) of MRI was 95% (95% confidence interval [CI] 84-105%) compared to In-111-labeled WBCS, which was 80% (95% CI 62-96%). The negative PV (NPV) of MRI was 80% (95% CI 68-92%) compared to 82% (95% CI 69-94%) for In-111-labeled WBCS. MRI showed a nonsignificant but better PPV for detecting IGF compared to In-111 leukocyte imaging. The NPVs for MRI and In-111-labeled WBCS were very near each other, with a very small advantage for In-111-WBCS. This comparison study suggested MRI as a primary diagnostic modality to investigate patients suspected of having aortic graft infections before In-111-labeled WBCS.

Prosthetic Vascular Graft Infection: The Role of 18F-FDG PET/CT

Graft infection after prosthetic vascular reconstruction is an uncommon but severe complication. The clinical presentation is often subtle and nonspecific and may occur long after surgery. Although defining a prosthetic vascular graft infection can be difficult, early diagnosis and treatment are important because of the relatively high rates of amputation and death. The present study assessed the role of PET/CT using 18F-FDG for the diagnosis of vascular graft infections. Thirty-nine patients (35 men and 4 women; age range, 44-82 y) with suspected vascular graft infection underwent 18F-FDG PET/CT. The performance of PET/CT for the diagnosis of an infectious process and its localization to the graft or soft tissues was assessed. The final diagnosis was based on histopathologic findings and microbiologic assays obtained at surgery or on clinical and imaging follow-up. PET/CT detected foci of increased 18F-FDG uptake suspected as infection in 27 patients and localized these findings to the graft in 16 patients. Vascular graft infection was confirmed in 14 of these patients (88%). PET/CT excluded graft involvement in 11 patients, and in 10 (91%) of these 11, long-term follow-up further confirmed that the infectious process was limited to surrounding soft tissues only. No abnormal 18F-FDG uptake was found in any of the 12 patients with no further evidence of infection. PET/CT had a sensitivity of 93%, specificity of 91%, positive predictive value of 88%, and negative predictive value of 96% for the diagnosis of vascular graft infection. 18F-FDG PET/CT is a reliable noninvasive imaging modality for the diagnosis of vascular graft-related infection. The precise anatomic localization of increased 18F-FDG uptake provided by PET/CT enables accurate differentiation between graft and soft-tissue infection.