The Experts below are selected from a list of 339 Experts worldwide ranked by ideXlab platform
Franklin D Lowy - One of the best experts on this subject based on the ideXlab platform.
-
role of biofilm in staphylococcus aureus and staphylococcus epidermidis ventricular assist device Driveline Infections
2011Co-Authors: Faustino A Toba, Carlos Arrecubieta, Hirokazu Akashi, Franklin D LowyAbstract:Objective Infections, especially those involving Drivelines, are among the most serious complications that follow ventricular assist device implantation. Staphylococci are the most common causes of these Infections. Once Driveline Infections are established, they can remain localized or progress as an ascending Infection to cause metastatic seeding of other tissue sites. Although elaboration of biofilm appears to be critical in prosthetic device Infections, its role as a facilitator of staphylococcal Infection and migration along the Driveline and other prosthetic devices is unclear. Methods A murine model of Driveline Infection was used to investigate staphylococcal migration along the Driveline. A biofilm-producing strain of Staphylococcus epidermidis and a Staphylococcus aureus strain and its intercellular adhesion gene cluster (ica) –negative (biofilm-deficient) isogenic mutant were used in these studies. Bacterial density on the Driveline and the underlying tissue was measured over time. Scanning electron microscopy was used to examine the morphology of S epidermidis biofilm formation as the Infection progressed. Results The biofilm-deficient S aureus mutant was less effective at infecting and migrating along the Driveline than the wild-type strain over time. However, the ica mutation had no effect on the ability of the strain to infect underlying tissue. S aureus exhibited more rapid migration than S epidermidis . Scanning electron microscopy revealed the deposition of host matrix on the Dacron material after implantation. This was followed by elaboration of a bacterial biofilm that correlated with more rapid migration along the Driveline. Conclusions Biofilm formation is a critical virulence determinant that facilitates the progression of Drivelines Infections.
-
sdrf a staphylococcus epidermidis surface protein contributes to the initiation of ventricular assist device Driveline related Infections
2009Co-Authors: Carlos Arrecubieta, Faustino A Toba, Manuel Prinz Von Bayern, Hirokazu Akashi, Mario C Deng, Yoshifumi Naka, Franklin D LowyAbstract:Staphylococcus epidermidis remains the predominant pathogen in prosthetic-device Infections. Ventricular assist devices, a recently developed form of therapy for end-stage congestive heart failure, have had considerable success. However, Infections, most often caused by Staphylococcus epidermidis, have limited their long-term use. The transcutaneous Driveline entry site acts as a potential portal of entry for bacteria, allowing development of either localized or systemic Infections. A novel in vitro binding assay using explanted Drivelines obtained from patients undergoing transplantation and a heterologous lactococcal system of surface protein expression were used to identify S. epidermidis surface components involved in the pathogenesis of Driveline Infections. Of the four components tested, SdrF, SdrG, PIA, and GehD, SdrF was identified as the primary ligand. SdrF adherence was mediated via its B domain attaching to host collagen deposited on the surface of the Driveline. Antibodies directed against SdrF reduced adherence of S. epidermidis to the Drivelines. SdrF was also found to adhere with high affinity to Dacron, the hydrophobic polymeric outer surface of Drivelines. Solid phase binding assays showed that SdrF was also able to adhere to other hydrophobic artificial materials such as polystyrene. A murine model of Infection was developed and used to test the role of SdrF during in vivo Driveline Infection. SdrF alone was able to mediate bacterial adherence to implanted Drivelines. Anti-SdrF antibodies reduced S. epidermidis colonization of implanted Drivelines. SdrF appears to play a key role in the initiation of ventricular assist device Driveline Infections caused by S. epidermidis. This pluripotential adherence capacity provides a potential pathway to Infection with SdrF-positive commensal staphylococci first adhering to the external Dacron-coated Driveline at the transcutaneous entry site, then spreading along the collagen-coated internal portion of the Driveline to establish a localized Infection. This capacity may also have relevance for other prosthetic device–related Infections.
Takuya Watanabe - One of the best experts on this subject based on the ideXlab platform.
-
Role of Gallium-SPECT-CT in the Management of Patients With Ventricular Assist Device-Specific Percutaneous Driveline Infection.
2019Co-Authors: Yuki Kimura, Osamu Seguchi, Kensuke Kuroda, Hiroki Mochizuki, Keiichiro Iwasaki, Koichi Toda, Yuto Kumai, Seiko Nakajima, Emi Tateishi, Takuya WatanabeAbstract:ABSTRACT Background Percutaneous Driveline Infection is a major complication of left ventricular assist device (LVAD). This study evaluated the role of gallium-67 single-photon emission computed tomography (Ga-SPECT)-CT in LVAD-specific percutaneous Driveline Infection. Methods Thirty-six patients with implantable continuous-flow LVAD, who underwent Ga-SPECT-CT to evaluate percutaneous Driveline Infections, were enrolled and divided into uptake and no-uptake groups based on tracer concentration uptake on Ga-SPECT-CT. Primary outcomes were surgical intervention and readmission for Driveline Infection. Results Twenty-two patients had uptake on Ga-SPECT-CT. No significant differences were noted in patient characteristics, wound appearance, or laboratory results. The prevalence of positive skin culture at the Driveline exit site (DLES), and usage and duration of antibiotics did not differ. However, the uptake group had higher 1-year event rates (surgical intervention: 39% vs 0%, P = .019; readmission: 74% vs 6.9%, P = .0016). In addition to positive skin culture at DLES and short duration of antibiotic therapy, uptake on Ga-SPECT-CT was a risk factor for surgical intervention (odds ratio 9.00; P = .018) and readmission (odds ratio 7.86; P = .0051). Conclusions Ga-SPECT-CT could be one of the clinical modalities for guiding the treatment of Driveline Infection in patients with a LVAD.
-
Role of Gallium-SPECT-CT in Predicting Outcomes of Patients with Ventricular Assist Device-Specific Percutaneous Driveline Infection
2019Co-Authors: Yuki Kimura, Osamu Seguchi, Kensuke Kuroda, Keiichiro Iwasaki, Koichi Toda, Yuto Kumai, Seiko Nakajima, Takuya Watanabe, Hideki Mochizuki, Y. MatsumotoAbstract:Purpose Percutaneous Driveline Infection is a major complication after left ventricular assist device (LVAD) implantation, causing pump Infection. Therefore, the precise diagnosis and evaluation of Driveline Infection are important. Recently, Fluor-18-fluorodeoxyglucose positron emission tomography is used for diagnosis of LVAD-specific and related Infections. However, the role of Gallium-67 single-photon emission computed tomography (Ga-SPECT)-CT has not been fully elucidated. We investigated whether Ga-SPECT-CT predicts outcomes of patients with LVAD-specific percutaneous Driveline Infection. Methods Thirty-six patients with implantable continuous-flow LVAD, who underwent Ga-SPECT-CT to diagnose and evaluate percutaneous Driveline Infections, were enrolled and divided into uptake and no-uptake groups based on tracer concentration uptake on Ga-SPECT-CT. Main outcomes were surgical intervention (debridement, translocation of Driveline exit site or pump exchange) and Driveline-Infection-caused readmission. Results Uptake on Ga-SPECT-CT revealed in 22 patients and regions of uptake were 9 (41%) Driveline exit site, 10 (45%) subcutaneous Driveline tunnel, and 3 (14%) sub-rectus Driveline tunnel. No significant differences were noted in patient characteristics, wound appearance, and blood test. The prevalence of positive skin culture of Driveline exit site as well as usage and duration of antibiotics did not differ (uptake vs no-uptake: 21/22, 95% vs 12/14, 86%, P = 0.30; 20/22, 91%, vs 11/14, 79%, P = 0.30; 20 vs 17 days, P = 0.19, respectively). However, the uptake group had a higher 1-year event rate (surgical intervention: 32% vs 0%, P = 0.037; readmission: 74% vs 6.9%, P = 0.0016). Conclusion Ga-SPECT-CT predicts surgical intervention and readmission in patients with LVAD-specific percutaneous Driveline Infection. Driveline Infections with uptake on Ga-SPECT-CT require aggressive treatment including early surgical treatment.
Yuki Kimura - One of the best experts on this subject based on the ideXlab platform.
-
Role of Gallium-SPECT-CT in the Management of Patients With Ventricular Assist Device-Specific Percutaneous Driveline Infection.
2019Co-Authors: Yuki Kimura, Osamu Seguchi, Kensuke Kuroda, Hiroki Mochizuki, Keiichiro Iwasaki, Koichi Toda, Yuto Kumai, Seiko Nakajima, Emi Tateishi, Takuya WatanabeAbstract:ABSTRACT Background Percutaneous Driveline Infection is a major complication of left ventricular assist device (LVAD). This study evaluated the role of gallium-67 single-photon emission computed tomography (Ga-SPECT)-CT in LVAD-specific percutaneous Driveline Infection. Methods Thirty-six patients with implantable continuous-flow LVAD, who underwent Ga-SPECT-CT to evaluate percutaneous Driveline Infections, were enrolled and divided into uptake and no-uptake groups based on tracer concentration uptake on Ga-SPECT-CT. Primary outcomes were surgical intervention and readmission for Driveline Infection. Results Twenty-two patients had uptake on Ga-SPECT-CT. No significant differences were noted in patient characteristics, wound appearance, or laboratory results. The prevalence of positive skin culture at the Driveline exit site (DLES), and usage and duration of antibiotics did not differ. However, the uptake group had higher 1-year event rates (surgical intervention: 39% vs 0%, P = .019; readmission: 74% vs 6.9%, P = .0016). In addition to positive skin culture at DLES and short duration of antibiotic therapy, uptake on Ga-SPECT-CT was a risk factor for surgical intervention (odds ratio 9.00; P = .018) and readmission (odds ratio 7.86; P = .0051). Conclusions Ga-SPECT-CT could be one of the clinical modalities for guiding the treatment of Driveline Infection in patients with a LVAD.
-
Role of Gallium-SPECT-CT in Predicting Outcomes of Patients with Ventricular Assist Device-Specific Percutaneous Driveline Infection
2019Co-Authors: Yuki Kimura, Osamu Seguchi, Kensuke Kuroda, Keiichiro Iwasaki, Koichi Toda, Yuto Kumai, Seiko Nakajima, Takuya Watanabe, Hideki Mochizuki, Y. MatsumotoAbstract:Purpose Percutaneous Driveline Infection is a major complication after left ventricular assist device (LVAD) implantation, causing pump Infection. Therefore, the precise diagnosis and evaluation of Driveline Infection are important. Recently, Fluor-18-fluorodeoxyglucose positron emission tomography is used for diagnosis of LVAD-specific and related Infections. However, the role of Gallium-67 single-photon emission computed tomography (Ga-SPECT)-CT has not been fully elucidated. We investigated whether Ga-SPECT-CT predicts outcomes of patients with LVAD-specific percutaneous Driveline Infection. Methods Thirty-six patients with implantable continuous-flow LVAD, who underwent Ga-SPECT-CT to diagnose and evaluate percutaneous Driveline Infections, were enrolled and divided into uptake and no-uptake groups based on tracer concentration uptake on Ga-SPECT-CT. Main outcomes were surgical intervention (debridement, translocation of Driveline exit site or pump exchange) and Driveline-Infection-caused readmission. Results Uptake on Ga-SPECT-CT revealed in 22 patients and regions of uptake were 9 (41%) Driveline exit site, 10 (45%) subcutaneous Driveline tunnel, and 3 (14%) sub-rectus Driveline tunnel. No significant differences were noted in patient characteristics, wound appearance, and blood test. The prevalence of positive skin culture of Driveline exit site as well as usage and duration of antibiotics did not differ (uptake vs no-uptake: 21/22, 95% vs 12/14, 86%, P = 0.30; 20/22, 91%, vs 11/14, 79%, P = 0.30; 20 vs 17 days, P = 0.19, respectively). However, the uptake group had a higher 1-year event rate (surgical intervention: 32% vs 0%, P = 0.037; readmission: 74% vs 6.9%, P = 0.0016). Conclusion Ga-SPECT-CT predicts surgical intervention and readmission in patients with LVAD-specific percutaneous Driveline Infection. Driveline Infections with uptake on Ga-SPECT-CT require aggressive treatment including early surgical treatment.
Angelo M Dellaquila - One of the best experts on this subject based on the ideXlab platform.
-
metabolic volume thresholding method comparison in patients suspected for lvad Driveline Infection in 18f fdg pet ct
2018Co-Authors: Nemanja Avramovic, Angelo M Dellaquila, Jurgen R Sindermann, Christian WenningAbstract:Poster: "EANM 18 / EP-0962 / Metabolic volume thresholding method comparison in patients suspected for LVAD Driveline Infection in 18F-FDG-PET/CT" by: "N. Avramovic1, A. M. Dell’Aquila2, J. R. Sindermann2, C. Wenning1; 1Department of Nuclear Medicine, University Hospital Munster, Munster, GERMANY, 2Department of Cardiac Surgery, University Hospital Munster, Munster, GERMANY"
-
metabolic volume performs better than suvmax in the detection of left ventricular assist device Driveline Infection
2017Co-Authors: Nemanja Avramovic, Angelo M Dellaquila, Jurgen R Sindermann, Matthias Weckesser, Danka Milankovic, Alexis Vrachimis, Christian WenningAbstract:A continuous-flow left ventricular assist device (LVAD) is a new and highly promising therapy in supporting end-stage heart failure patients, either bridging them to heart transplantation or as a destination therapy. Infection is one of the major complications associated with LVAD implants. 18F–FDG PET/CT has already been shown to be useful in the detection of LVAD Infection. The goal of this study was to compare the diagnostic accuracy of different PET analysis techniques (visual grading versus SUVmax and metabolic volume). We retrospectively analyzed 48 patients with implanted LVAD who underwent an 18F–FDG PET/CT that were either suspected to have a Driveline or device Infection or inflammation of unknown origin. PET/CT was analyzed qualitatively (visual grading) and quantitatively (SUVmax and metabolic volume) and matched to the final clinical diagnosis concerning Driveline Infection. The final diagnosis (standard of reference) was made at the end of clinically recorded follow-up or transplantation and included microbiological cultures of the Driveline exit site and/or surgical samples, and clinical signs of Infection despite negative cultures as well as recurrence of symptoms. Sensitivity, specificity, positive and negative predictive value were 87.5%, 79%, 81% and 86% for visual score, 87.5%, 87.5%, 87.5% and 87.5% for SUVmax and 96%, 87.5%, 88.5%, 95.5% for metabolic volume, respectively. ROC analysis revealed an AUC of .929 for SUVmax and .969 for metabolic volume. Both SUVmax and metabolic volume had a high detection rate of patients with Driveline Infection (21/24 = 91.5% true positive vs. 23/26 = 88.5% true positive, respectively). However, metabolic volume detected more patients without any Infection correctly (1/22 = 4.5% false negative vs. 3/24 = 12.5% false negative). 18F–FDG PET/CT is a valuable tool for the diagnosis of LVAD Driveline Infection with high diagnostic accuracy. Particularly the use of the metabolic volume yields very high accuracy and performs slightly better than SUVmax.
-
contributory role of fluorine 18 fluorodeoxyglucose positron emission tomography computed tomography in the diagnosis and clinical management of Infections in patients supported with a continuous flow left ventricular assist device
2016Co-Authors: Angelo M Dellaquila, Jurgen R Sindermann, Christian Wenning, Stefano Mastrobuoni, Sebastian Alles, Welp Henryk, Stefan R B Schneider, Heinz Deschka, M SchererAbstract:Background The current study sought to demonstrate the advantages offered by fluorine 18-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) in patients supported with continuous-flow left ventricular assist devices (CF-LVADs) in detecting Infection and the consequent effect on clinical decisions. Methods Between April 2009 and September 2013, 40 PET examinations were performed in 31 patients (78.1% men; mean age, 51.0 ± 14.9 years) supported with a CF-LVAD. In group A (19 examinations in 14 patients), PET/CT was performed to detect infectious focus in patients without external signs of Driveline involvement but with at least two of the following Infection signs: recurrent fever, positive blood culture, or elevated infectious indicators. In group B (21 examinations in 17 patients), PET/CT aimed to assess the internal extension of Infection in patients with external signs of Driveline Infection. Results In 50% of the cases of the patients in group A, abnormal 18 F-FDG uptake (9 patients) was related to VAD components. Matching the results with the final diagnosis, we reported 9 true-positive, 8 true-negative, no false-negative, and 2 false-positive findings. New information unrelated to VAD was found in 9 patients (50%): pneumonia in 3, colon diverticulitis in 3, sternal dehiscence in 1, paravertebral abscess in 1, and erysipelas in 1. In group B, superficial abnormal 18 F-FDG uptake was found at the piercing site of the Driveline in 2 patients, deeper extension of Infection along the Driveline in 10, initial involvement of the pump housing in 2, and full involvement of the device in 4. These findings contributed to changing the clinical management in 84.2% of group A patients and in 85.7% of group B patients: 16 patients were scheduled for urgent transplantation, 2 underwent surgical revision of the Driveline, 7 required prolonged antibiotic therapy, and 3 underwent colonoscopy. Conclusions This single-center experience highlights the diagnostic value of PET/CT in detecting the localization and internal extension of Infection to internal VAD components. Moreover, this information notably influences the therapeutic management.
Christian Wenning - One of the best experts on this subject based on the ideXlab platform.
-
metabolic volume thresholding method comparison in patients suspected for lvad Driveline Infection in 18f fdg pet ct
2018Co-Authors: Nemanja Avramovic, Angelo M Dellaquila, Jurgen R Sindermann, Christian WenningAbstract:Poster: "EANM 18 / EP-0962 / Metabolic volume thresholding method comparison in patients suspected for LVAD Driveline Infection in 18F-FDG-PET/CT" by: "N. Avramovic1, A. M. Dell’Aquila2, J. R. Sindermann2, C. Wenning1; 1Department of Nuclear Medicine, University Hospital Munster, Munster, GERMANY, 2Department of Cardiac Surgery, University Hospital Munster, Munster, GERMANY"
-
metabolic volume performs better than suvmax in the detection of left ventricular assist device Driveline Infection
2017Co-Authors: Nemanja Avramovic, Angelo M Dellaquila, Jurgen R Sindermann, Matthias Weckesser, Danka Milankovic, Alexis Vrachimis, Christian WenningAbstract:A continuous-flow left ventricular assist device (LVAD) is a new and highly promising therapy in supporting end-stage heart failure patients, either bridging them to heart transplantation or as a destination therapy. Infection is one of the major complications associated with LVAD implants. 18F–FDG PET/CT has already been shown to be useful in the detection of LVAD Infection. The goal of this study was to compare the diagnostic accuracy of different PET analysis techniques (visual grading versus SUVmax and metabolic volume). We retrospectively analyzed 48 patients with implanted LVAD who underwent an 18F–FDG PET/CT that were either suspected to have a Driveline or device Infection or inflammation of unknown origin. PET/CT was analyzed qualitatively (visual grading) and quantitatively (SUVmax and metabolic volume) and matched to the final clinical diagnosis concerning Driveline Infection. The final diagnosis (standard of reference) was made at the end of clinically recorded follow-up or transplantation and included microbiological cultures of the Driveline exit site and/or surgical samples, and clinical signs of Infection despite negative cultures as well as recurrence of symptoms. Sensitivity, specificity, positive and negative predictive value were 87.5%, 79%, 81% and 86% for visual score, 87.5%, 87.5%, 87.5% and 87.5% for SUVmax and 96%, 87.5%, 88.5%, 95.5% for metabolic volume, respectively. ROC analysis revealed an AUC of .929 for SUVmax and .969 for metabolic volume. Both SUVmax and metabolic volume had a high detection rate of patients with Driveline Infection (21/24 = 91.5% true positive vs. 23/26 = 88.5% true positive, respectively). However, metabolic volume detected more patients without any Infection correctly (1/22 = 4.5% false negative vs. 3/24 = 12.5% false negative). 18F–FDG PET/CT is a valuable tool for the diagnosis of LVAD Driveline Infection with high diagnostic accuracy. Particularly the use of the metabolic volume yields very high accuracy and performs slightly better than SUVmax.
-
contributory role of fluorine 18 fluorodeoxyglucose positron emission tomography computed tomography in the diagnosis and clinical management of Infections in patients supported with a continuous flow left ventricular assist device
2016Co-Authors: Angelo M Dellaquila, Jurgen R Sindermann, Christian Wenning, Stefano Mastrobuoni, Sebastian Alles, Welp Henryk, Stefan R B Schneider, Heinz Deschka, M SchererAbstract:Background The current study sought to demonstrate the advantages offered by fluorine 18-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography/computed tomography (PET/CT) in patients supported with continuous-flow left ventricular assist devices (CF-LVADs) in detecting Infection and the consequent effect on clinical decisions. Methods Between April 2009 and September 2013, 40 PET examinations were performed in 31 patients (78.1% men; mean age, 51.0 ± 14.9 years) supported with a CF-LVAD. In group A (19 examinations in 14 patients), PET/CT was performed to detect infectious focus in patients without external signs of Driveline involvement but with at least two of the following Infection signs: recurrent fever, positive blood culture, or elevated infectious indicators. In group B (21 examinations in 17 patients), PET/CT aimed to assess the internal extension of Infection in patients with external signs of Driveline Infection. Results In 50% of the cases of the patients in group A, abnormal 18 F-FDG uptake (9 patients) was related to VAD components. Matching the results with the final diagnosis, we reported 9 true-positive, 8 true-negative, no false-negative, and 2 false-positive findings. New information unrelated to VAD was found in 9 patients (50%): pneumonia in 3, colon diverticulitis in 3, sternal dehiscence in 1, paravertebral abscess in 1, and erysipelas in 1. In group B, superficial abnormal 18 F-FDG uptake was found at the piercing site of the Driveline in 2 patients, deeper extension of Infection along the Driveline in 10, initial involvement of the pump housing in 2, and full involvement of the device in 4. These findings contributed to changing the clinical management in 84.2% of group A patients and in 85.7% of group B patients: 16 patients were scheduled for urgent transplantation, 2 underwent surgical revision of the Driveline, 7 required prolonged antibiotic therapy, and 3 underwent colonoscopy. Conclusions This single-center experience highlights the diagnostic value of PET/CT in detecting the localization and internal extension of Infection to internal VAD components. Moreover, this information notably influences the therapeutic management.
