Open Chest Approach Lead Extraction in a Patient with a Large Vegetation: The Importance of Multidisciplinary Approach, Advanced Imaging, and Procedural Planning.

We present a complex case of cardiac implantable electronic device infection and extraction in the setting of bacteremia, large lead vegetation, and patent foramen ovale. Following a comprehensive preprocedural workup including transesophageal echocardiogram and computed tomography lead extraction protocol, in addition to the involvement of multiple subspecialties, an open chest approach to extraction was deemed a safer option for eradication of the patient's infection. Despite percutaneous techniques having evolved as the preferred extraction method during the last few decades, this case demonstrates the importance of a thorough evaluation at an experienced center to determine the need for open chest extraction.

Manifestations of Prosthetic Valve Endocarditis: Lessons From Multimodality Imaging and Pathological Correlation.

Heart valve replacement has steadily increased over the past decades due to improved surgical mortality, an aging population, and the increasing use of transcatheter valve technology. With these developments, prosthetic valve complications, including prosthetic valve endocarditis, are increasingly encountered. In this review, we aim to characterize the manifestations of prosthetic valve endocarditis using representative case studies from our institution to highlight the advances and contributions of modern multimodality imaging techniques.

18F-FDG PET/CT in left ventricular assist device infections: In-depth characterization and clinical implications.

BACKGROUND: Previous retrospective studies suggest a good diagnostic performance of 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET)/computed tomography (CT) in left ventricular assist device (LVAD) infections. Our aim was to prospectively evaluate the role of PET/CT in the characterization and impact on clinical management of LVAD infections. METHODS: A total of 40 patients (aged 58 [53-62] years) with suspected LVAD infection and 5 controls (aged 69 [64-71] years) underwent 18F-FDG-PET/CT. Four LVAD components were evaluated: exit site and subcutaneous driveline (peripheral), pump pocket, and outflow graft. The location with maximal uptake was considered the presumed site of infection. Infection was confirmed by positive culture (exit site or blood) and/or surgical findings. RESULTS: Visual uptake was present in 40 patients (100%) in the infection group vs 4 (80%) control subjects. For each individual component, the presence of uptake was more frequent in the infection than in the control group. The location of maximal uptake was most frequently the pump pocket (48%) in the infection group and the peripheral components (75%) in the control group. Maximum standard uptake values (SUVmax) were higher in the infection than in the control group: SUVmax (average all components): 6.9 (5.1-8.5) vs 3.8 (3.7-4.3), p = 0.002; SUVmax (location of maximal uptake): 10.6 ± 4.0 vs 5.4 ± 1.9, p = 0.01. Pump pocket infections were more frequent in patients with bacteremia than without bacteremia (79% vs 31%, p = 0.011). Pseudomonas (32%) and methicillin-susceptible Staphylococcus aureus (29%) were the most frequent pathogens and were associated with pump pocket infections, while Staphylococcus epidermis (11%) was associated with peripheral infections. PET/CT affected the clinical management of 83% of patients with infection, resulting in surgical debridement (8%), pump exchange (13%), and upgrade in the transplant listing status (10%), leading to 8% of urgent transplants. CONCLUSIONS: 18F-FDG-PET/CT enables the diagnosis and characterization of the extent of LVAD infections, which can significantly affect the clinical management of these patients.

The Value of Preoperative Ultrasound-Determined Fluid Film and Joint Aspiration in Revision Hip Arthroplasty.

BACKGROUND: Data regarding the diagnostic value of ultrasound (US)-determined fluid film and joint aspiration prior to revision total hip arthroplasty for suspected periprosthetic joint infections (PJIs) are limited. This study aimed to analyze the value of US-determined fluid film, characterized the preoperative and intraoperative microbiological spectrum and resistance patterns, and compared the concordance between preoperative synovial fluid and intraoperative culture results. METHODS: We analyzed 366 US examinations from 324 patients prior to revision total hip arthroplasty. Selected cases were grouped into clearly infected, noninfected, and inconclusive cohorts, according to the International Consensus Meeting 2018 Criteria. For US-determined fluid film <1 mm, no aspiration was performed based on our institutional protocol. Patients were grouped into no aspiration (144 of 366; [39.3%]), dry tap (21 of 366; [5.7%]), and a successful tap (201 of 366; [54.9%]). The microbiological spectrum and antibiograms were compared between preoperative and intraoperative results. RESULTS: The absence of US-determined fluid film showed no correlation with the presence of a hip PJI. Overall, 31.9% cases of the no-aspiration group had a PJI. In total, 13.5% discrepancies were found between successful taps and intraoperative cultures. The most prevalent microorganisms in preoperative synovial fluid were Staphylococcus epidermidis and Staphylococcus aureus (20.8%), while intraoperatively S. epidermidis (26.3%) and Cutibacterium acnes (14.5%) were leading. Additional microorganisms were identified in 32.5% of intraoperative cultures. There were no differences between resistance patterns of preoperative and intraoperative concordant microorganisms. CONCLUSIONS: Absence of US-determined fluid film cannot rule out the presence of a hip PJI. Combined microbiological results from hip US aspirations and subsequent surgical procedures are crucial to design an effective treatment for suspected hip PJI.

The Role of Antigranulocyte Scintigraphy in Diagnosis of Aortic Graft Infection and Evaluation of Treatment Outcome.

BACKGROUND: The aim of this study was to assess the eventual added benefit of antigranulocyte monoclonal antibodies scintigraphy for the diagnostic imaging of aortic graft infection (AGI) and its role in evaluation of treatment outcome. METHODS: A population-based, retrospective, register-based analysis was carried out of all patients with infected aortic grafts after treatment for aneurysmal or aortoiliac occlusive disease at Karolinska University Hospital, covering the greater Stockholm area during November 2012-December 2020. Cases were based on the definitions in the 2016 Management of Aortic Graft Infection Collaborations consensus. Using the in-hospital electronic patient registry (Take Care®) and the Swedish National Registry for Vascular Surgery (Swedvasc), 835 patients who had been treated for aortic aneurysms or aortoiliac occlusive disease were identified. The diagnostic arsenal of laboratory tests, computed tomography (CT), and clinical signs has been supplemented by antigranulocyte monoclonal antibodies (anti-G mAb) scintigraphy. Data were analyzed using SPSS Statistics. RESULTS: Eighteen cases of AGI out of 835 operations incorporating aortic grafts during the period were identified. Fourteen patients (78%) were categorized as diagnosed AGI (AGI-D), and the remaining 4 (22%) were classified as suspected AGI (AGI-S). In the AGI-D group (n = 14), 10 patients (71%) had positive CTs and 4 (29%) had low-probability CTs. In the group of 10 positive CTs, 9 patients also had positive scintigraphy scans with only one negative scintigraphy scan. There were no negative scintigraphy scans without ongoing antibiotic treatment at the time of investigation. In 15 of 18 cases, a culprit agent was identified, either preoperatively or perioperatively. Thirteen of the 18 patients were treated solely by antibiotics, whereas 5 underwent surgical treatment in addition to antibiotic treatment. The outcome has been divided into 3 groups: infection-free (n = 6; 33%), lifelong antibiotic treatment (n = 7; 39%), and deceased (n = 5; 28%). CONCLUSIONS: The imaging modalities in AGI diagnostics are a cornerstone of the investigative work-up, complemented by clinical signs and laboratory methods. The main advantage conveyed by anti-G mAb scintigraphy is in postoperative imaging and its ability to differentiate between infection and general postoperative changes in the areas of concern. We have identified 6 patients in our cohort in whom antibiotic therapy was discontinued after a negative anti-G mAb scintigraphy scan. Anti-G mAb scintigraphy may fulfill a unique need for diagnosis in suspected cases, evaluation of therapeutic efficacy in patients requiring long-term antibiotic treatment, and aiding in the decision to discontinue antibiotic therapy.

Early results of a novel modular knee arthrodesis implant after uncontrolled periprosthetic knee joint infection.

AIM: The aim of this study is to evaluate the functional outcomes and complications after non-fusion knee arthrodesis with a modular segmental intramedullary implant used for infected total knee arthroplasty revisions. METHODS: A retrospective review of the patients who had been surgically treated with a modular intramedullary arthrodesis implant for recurrent infection after revision TKA between January 2016 and February 2020 were included. The indications for arthrodesis were failed infected TKA with massive bone loss, deficient extensor mechanism and poor soft tissue coverage that precluded joint reconstruction with revision TKA implants. Clinical outcomes were assesed with visual analogue scale for pain (pVAS), Oxford knee score (OKS) and 12-item short form survey (SF-12). Full-length radiographs were used to verify limb length discrepancies (LLD). RESULTS: Fourteen patients (4 male and 10 female) patients with a mean age of 69.3 (range, 59 to 81) years at time of surgery were available for final follow-up at a mean of 28.8 months (range, 24-35 months). All clinical outcome scores improved at the final follow-up (pVAS, 8.5 to 2.6, p = .01; OKS, 12.6 to 33.8, p = .02; SF-12 physical, 22.9 to 32.1, p = .01 and SF-12 mental, 27.7 to 40.2, p = .01). The mean LLD was 1.0 cm (range, + 15 - 2.3 cm). Re-infection was detected in three patients (21.4%). Two patients were managed with suppressive antibiotic treatment and a third patient required repeat 2-stage revision procedure. In one patient, a periprosthetic femur fracture was observed and treated with plate osteosynthesis. CONCLUSION: Uncontrolled infection after total knee arthroplasty can be effectively treated with arthrodesis using a modular intramedullary nail and satisfactory functional results can be obtained. LEVEL OF EVIDENCE: Level 4, Retrospective cohort study.

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.

Diagnostic value of magnetic resonance imaging for patients with periprosthetic joint infection: a systematic review.

PURPOSE: The purpose of this study was to provide a critical systematic review of the role of magnetic resonance imaging (MRI) as a noninvasive method to assess periprosthetic joint infections (PJIs). METHODS: The electronic databases PubMed and EMBASE were searched, since their inception up to March 27, 2022. The included studies evaluated the reproducibility and accuracy of MRI features to diagnose PJIs. The article quality assessment was conducted by the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) and Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2). RESULTS: Among 1909 studies identified in the initial search, 8 studies were eligible for final systematic review. The included studies evaluated the reproducibility and accuracy of MRI features to diagnose PJIs. Seven of 8 studies showed good to excellent reliability, but only one article among them in which accuracy was evaluated had a low risk of bias. The intraclass correlation coefficient (ICC) and Cohen coefficient (κ) varied between 0.44 and 1.00. The accuracy varied between 63.9% and 94.4%. Potential MRI features, such as lamellated hyperintense synovitis, edema, fluid collection, or lymphadenopathy, might be valuable for diagnosing PJIs. CONCLUSION: The quality of the evidence regarding the role of MRI for PJIs diagnosis was low. There is preliminary evidence that MRI has a noteworthy value of distinguishing suspected periprosthetic joint infection in patients with total knee arthroplasty or total hip arthroplasty, but the definition of specific MRI features related to PJIs diagnosis lacks consensus and standardization. Large-scale studies with robust quality were required to help make better clinical decisions in the future.

Diagnostic accuracy of positron emission tomography/computerized tomography for periprosthetic joint infection of hip: systematic review and meta-analysis.

BACKGROUND: American Academy of Orthopaedic Surgeons (AAOS) has provided the guidelines for diagnosing a patient with periprosthetic joint infection including the use of positron emission tomography/computed tomography (PET/CT). Systematic evidence focussing on periprosthetic joint infection (PJI) of hip is limited, which also contains limited number of studies. Hence, the current study aims to perform a pooled analysis of all studies that have assessed the diagnostic accuracy of PET/CT for PJI of hip. METHODS: Searches were done in PubMed Central, EMBASE, MEDLINE, SCOPUS and Cochrane library until December 2022. Meta-analysis was carried out using random-effects model. With 95% confidence intervals (CIs), pooled sensitivity and specificity were reported. RESULTS: Twenty-six studies met the inclusion criteria. The pooled sensitivity of PET/CT was 89% (95% CI 84-93%), while the pooled specificity was 86% (95% CI 79-91%). The AUROC was 0.94 (95% CI 0.72-0.99). There was statistically significant heterogeneity (p < 0.001) with I2 value of 96%. The diagnostic odds ratio was 52 (95% CI 26-106). Likelihood ratio positive was 6.5 (95% CI 4.1-10.3) and negative was 0.13 (95% CI 0.08-0.19). CONCLUSION: Our study found that PET/CT was found to have higher level of accuracy in terms of sensitivity and specificity. Further large-scale research can help to find answers for such questions and provide final conclusive evidence on the inclusion of the imaging modality into the routine clinical practice guidelines for suspected periprosthetic joint infection patients.

Prognosis and follow-up of patients with prosthetic valve endocarditis treated conservatively in relation to WBC-SPECT imaging.

BACKGROUND: Our objective was to evaluate in patients with prosthetic valve endocarditis (PVE) treated conservatively, the prognostic value of white blood cell (WBC) signal intensity on SPECT and to describe the evolution of the WBC signal under antibiotics. METHODS: Patients with PVE treated conservatively and positive WBC-SPECT imaging were identified retrospectively. Signal intensity was classified as intense if equal to or higher, or mild if lower, than the liver signal. Clinical, biological, imaging and follow-up information were collected from medical files. RESULTS: Among 47 patients, WBC signal was classified as intense in 10 patients and as mild, in 37. The incidence of the primary composite endpoint (death, late cardiac surgery, or relapse) was significantly higher in patients with intense vs. mild signal (90% vs. 11%). Twenty-five patients underwent a second WBC-SPECT imaging during follow-up. The prevalence of WBC signal decreased progressively from 89% between 3 and 6 weeks to 42% between 6 and 9 weeks and 8% more than 9 weeks after initiation of antibiotics. CONCLUSIONS: In patients with PVE treated conservatively, intense WBC signal was associated with poor outcome. WBC-SPECT imaging appears as an interesting tool for risk stratification and to monitor locally the efficacy of antibiotic treatment.

HGT: A Hierarchical GCN-Based Transformer for Multimodal Periprosthetic Joint Infection Diagnosis Using Computed Tomography Images and Text.

Prosthetic joint infection (PJI) is a prevalent and severe complication characterized by high diagnostic challenges. Currently, a unified diagnostic standard incorporating both computed tomography (CT) images and numerical text data for PJI remains unestablished, owing to the substantial noise in CT images and the disparity in data volume between CT images and text data. This study introduces a diagnostic method, HGT, based on deep learning and multimodal techniques. It effectively merges features from CT scan images and patients' numerical text data via a Unidirectional Selective Attention (USA) mechanism and a graph convolutional network (GCN)-based Feature Fusion network. We evaluated the proposed method on a custom-built multimodal PJI dataset, assessing its performance through ablation experiments and interpretability evaluations. Our method achieved an accuracy (ACC) of 91.4% and an area under the curve (AUC) of 95.9%, outperforming recent multimodal approaches by 2.9% in ACC and 2.2% in AUC, with a parameter count of only 68 M. Notably, the interpretability results highlighted our model's strong focus and localization capabilities at lesion sites. This proposed method could provide clinicians with additional diagnostic tools to enhance accuracy and efficiency in clinical practice.

First case report of splenomegaly with splenic infarction due to aortic graft infection.

BACKGROUND: Diagnosis of aortic graft infections (AGI) is challenging. Here, we report a case of AGI with splenomegaly and splenic infarction. CASE PRESENTATION: A 46-year-old man who underwent total arch replacement for Stanford type A acute aortic dissection one year prior presented to our department with fever, night sweat, and a 20-kg weight loss over several months. Contrast-enhanced computed tomography (CT) revealed splenic infarction with splenomegaly, fluid collection, and thrombus around the stent graft. Positron emission tomography-CT (PET-CT) revealed abnormal 18F-fluorodeoxyglucose uptake in the stent graft and spleen. Transesophageal echocardiography revealed no vegetations. The patient was diagnosed with an AGI and underwent graft replacement. Blood and tissue cultures in the stent graft yielded Enterococcus faecalis. After the surgery, the patient was successfully treated with antibiotics. CONCLUSIONS: Splenic infarction and splenomegaly are the clinical findings of endocarditis but are rare in graft infection. These findings could be helpful to diagnose graft infections, which is often challenging.

Detection of inguinal lymph nodes is promising for the diagnosis of periprosthetic joint infection.

Background: Localized inguinal lymphadenopathy often represents lower extremity pathogen infection, while normalized lymphadenopathy is associated with infection regression. We hypothesized that inguinal lymph nodes (LNs) were enlarged in Periprosthetic Joint Infection (PJI) patients and that normalized inguinal LNs would be a promising way to determine the timing of reimplantation. Methods: We prospectively enrolled 176 patients undergoing primary and revision hip or knee arthroplasty. All patients underwent ultrasound examination of inguinal LNs preoperatively. The diagnostic value of inguinal LNs in PJI was evaluated by the receiver operating characteristic (ROC) curve. Results: The median level of inguinal LNs was 26mm in the revision for PJI group compared with 12 mm in the aseptic revision group (p< 0.0001). The size of the inguinal LNs well distinguishes PJI from aseptic failure (AUC= 0.978) compare with ESR (AUC= 0.707) and CRP (AUC= 0.760). A size of 19mm was determined as the optimal threshold value of the inguinal LNs for the diagnosis of PJI, with a sensitivity of 92% and specificity of 96%. Conclusion: Ultrasonic analysis of inguinal LNs is a valuable piece of evidence for the diagnosis of PJI and evaluation of persistent infection.

Left ventricular assist device infection on 18F-flourodeoxyglucose positron emission tomography.

The rising prevalence of heart failure with limited transplant availability has resulted in increased use of continuous left ventricular assist device (LVAD) support. LVAD driveline remains exposed to environment which predisposes it to high rates of infection. We describe a case of a persistent driveline infection in a patient for which 18F-FDG PET/CT was utilized to diagnose deep-seated infection.

Intracardiac echocardiogram to diagnose infective endocarditis after transcatheter aortic valve-in-valve implantation.

A 70-year-old man with history of transcatheter aortic valve-in-valve implantation was admitted because of suspected infective endocarditis (IE). Transesophageal echocardiogram did not reveal any vegetations, as the metallic stent frames caused significant artifacts. Position emission tomography was also negative. Intracardiac echocardiogram (ICE) was performed retrogradely through the ascending aorta, which showed clear vegetations over the stent frame of the transcatheter heart valve. Endocarditis after transcatheter aortic valve implantation was not uncommon. With increasing use of valve-in-valve procedures, echocardiographic diagnosis of IE would be more challenging. This case demonstrated the advantage of ICE over conventional echocardiography in visualizing the neo-aortic valve complex for diagnosing IE.