Geometrical Changes of the Aorta as Predictors for Thromboembolic Events After EVAR With the Anaconda Stent-Graft.

PURPOSE: Thromboembolic events (TE), including limb graft occlusion (LGO) and distal limb embolization (DLE), are common complications after endovascular aneurysm repair (EVAR). The aim of this study was to find predictors for TE in patients treated with the Anaconda stent-graft for infrarenal aneurysms. MATERIALS AND METHODS: Geometrical and anatomical variables were retrospectively analyzed in a consecutive Anaconda cohort. Pre- and postoperative CT scans were used to derive geometrical parameters length, curvature, torsion, and tortuosity index (TI) from the center lumen lines (CLLs). Limb characteristics, pre-to-post EVAR and mid-term-follow-up changes in the parameters were evaluated for their predictive value for TE. RESULTS: Eighty-four patients (mean age 74±8.3 years, 74 men) were enrolled. The risk of TE was lowered with pre-to-post implant decreasing TI (steps of 0.05: OR: 1.30, 95% CI: 1.01-1.66, p=0.04), pre-to-post implant decreasing mean curvature (OR: 1.08, 95% CI: 1.01-1.16, p=0.03), and a larger degree of circumferential common iliac artery (CIA) calcification (OR: 0.98, 95% CI: 0.97-1.00, p=0.03). The only LGO predictor was the caudal relocation of maximal curvature after EVAR (OR: 1.01, 95% CI: 1.00-1.01, p=0.04). Preventors of DLE were CIA diameter (OR: 0.87, 95% CI: 0.76-0.99, p=0.04), circumferential CIA calcification (OR: 0.97, 95% CI: 0.95-1.00, p=0.03), mean and maximal curvature of the preoperative aortoiliac trajectory (OR: 0.86, 95% CI: 0.79-0.94, p<0.01 and OR: 0.97, 95% CI: 0.95-1.00, p=0.03, respectively) and pre-to-postoperative decrease in mean curvature (OR: 1.11, 95% CI: 1.02-1.21, p=0.02). Midterm TE predictors were length (OR: 0.95, 95% CI: 0.89-1.01, p=0.08) and torsion maximum location (OR: 1.01, 95% CI: 0.99-1.01, p=0.10). CONCLUSION: The present study confirms that treatment of infrarenal AAA with an Anaconda stent-graft is related to a relatively high TE rate which decreases with a pre-to-postoperative reduction in curvature and TI, and a larger degree of circumferential CIA calcification. In other words, more aortoiliac straightening and more circumferential CIA calcification may prevent TE development after EVAR with this stent-graft.

Reliability assessment of hyperspectral imaging with the HyperView™ system for lower extremity superficial tissue oxygenation in young healthy volunteers.

PURPOSE: Hyperspectral imaging (HSI) is a noninvasive spectroscopy technique for determining superficial tissue oxygenation. The HyperView™ system is a hand-held camera that enables perfusion image acquisition. The evaluation of superficial tissue oxygenation is warranted in the evaluation of patients with peripheral arterial disease. The aim was to determine the reliability of repeated HSI measurements. METHODS: In this prospective cohort study, HSI was performed on 50 healthy volunteers with a mean age of 26.4 ± 2.5 years, at the lower extremity. Two independent observers performed HSI during two subsequent measurement sessions. Short term test-retest reliability and intra- and inter-observer reliability were determined, and generalizability and decision studies were performed. Transcutaneous oxygen pressure (TcPO2) measurements were also performed. RESULTS: The short term test-retest reliability was good for the HSI values determined at the lower extremity, ranging from 0.72 to 0.90. Intra- and inter-observer reliability determined at different days were poor to moderate for both HSI (0.24 to 0.71 and 0.30 to 0.58, respectively) and TcPO2 (0.54 and 0.56, and 0.51 and 0.31, respectively). Reliability can be increased to >0.75 by averaging two measurements on different days. CONCLUSION: This study showed good short term test-retest reliability for HSI measurements, however low intra- and inter-observer reliability was observed for tissue oxygenation measurements with both HSI and TcPO2 performed at separate days in young healthy volunteers. Reliability of HSI can be improved when determined as a mean of two measurements taken on different days.

Real World Practice Deviation from Nationwide Guidelines in Patients with Intermittent Claudication.

OBJECTIVE: Patients with intermittent claudication (IC) are initially treated with supervised exercise therapy (SET), as advised by national and international guidelines. Dutch health insurance companies and the Dutch National Health Care Institute suggested an 87% compliance rate with these guidelines in the Netherlands in 2017 and judged this to be undesirably low. The aim of this study was to evaluate compliance with IC guidelines and to elaborate on the reasons for deviating from them (practice variation) in a large teaching hospital. METHODS: A retrospective single centre cohort study was conducted at a large teaching hospital in the Netherlands. In total, 420 patients with newly diagnosed IC between 1 January 2017 and 31 December 2018 were analysed. Data included risk profiles and prescribed therapies. RESULTS: For all 420 included patients, the compliance rate with the guidelines for SET was 80.5%. The rate of adequately motivated and defensible practice variation was 15.7%; the rate of unjustified practice variation was 3.8%. Meaningful care was seen in 96.2% of cases. CONCLUSION: Deviation from IC guidelines was found in 19.5% of patients. Almost three quarters of this deviation can be explained by the decision to provide personalised, meaningful care.

A Systematic Review and Critical Appraisal of Peri-Procedural Tissue Perfusion Techniques and their Clinical Value in Patients with Peripheral Arterial Disease.

OBJECTIVE: Many techniques have been introduced to enable quantification of tissue perfusion in patients with peripheral arterial disease (PAD). Currently, none of these techniques is widely used to analyse real time tissue perfusion changes during endovascular or surgical revascularisation procedures. The aim of this systematic review was to provide an up to date overview of the peri-procedural applicability of currently available techniques, diagnostic accuracy of assessing tissue perfusion and the relationship with clinical outcomes. DATA SOURCES: MEDLINE, Embase, CINAHL, and the Cochrane Central Register of Controlled Trials. REVIEW METHODS: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic review and Meta-Analysis (PRISMA) guidelines. Four electronic databases were searched up to 31 12 2020 for eligible articles: MEDLINE, Embase, CINAHL and the Cochrane Central Register of Controlled Trials. Eligible articles describing a perfusion measurement technique, used in a peri-procedural setting before and within 24 hours after the revascularisation procedure, with the aim of determining the effect of intervention in patients with PAD, were assessed for inclusion. The QUADAS-2 tool was used to assess the risk of bias and applicability of the studies. RESULTS: An overview of 10 techniques found in 26 eligible articles focused on study protocols, research goals, and clinical outcomes is provided. Non-invasive techniques included laser speckle contrast imaging, micro-lightguide spectrophotometry, magnetic resonance imaging perfusion, near infrared spectroscopy, skin perfusion pressure, and plantar thermography. Invasive techniques included two dimensional perfusion angiography, contrast enhanced ultrasound, computed tomography perfusion imaging, and indocyanine green angiography. The results of the 26 eligible studies, which were mostly of poor quality according to QUADAS-2, were without exception, not sufficient to substantiate implementation in daily clinical practice. CONCLUSION: This systematic review provides an overview of 10 tissue perfusion assessment techniques for patients with PAD. It seems too early to appoint one of them as a reference standard. The scope of future research in this domain should therefore focus on clinical accuracy, reliability, and validation of the techniques.

Wound swab and wound biopsy yield similar culture results.

The question remains whether wound swabs yield similar culture results to the traditional gold standard, biopsies. Swabs are not invasive and easy to perform. However, they are believed to capture microorganisms from the surface rather than microorganisms that have invaded tissue. Several studies compared swabs and biopsies using different populations and sampling methods, complicating the ability to draw conclusions for clinical practice. This study aimed to compare swab and biopsy in clinical practice, by including a variety of wounds and using standard sampling and culture procedures. Swabs (Levine technique) and biopsies were taken for microbiological culture in a standardized manner from the same location of one wound for each patient. Statistical analyses were performed to determine overall agreement, and observed agreement and kappa for specific microorganisms. A variety of wounds of 180 patients from different healthcare facilities in The Netherlands were included. Skin flora was more frequently cultured from swabs, resulting in similar recovery rates when excluding skin flora (1.34 vs 1.35). Swabs were able to identify all microorganisms cultured from biopsies in 131 wounds (72.8%) wounds. Most frequently identified organisms were Staphylococcus aureus, Pseudomonas aeruginosa, and beta-haemolytic streptococci species. Observed agreement and kappa for these organisms varied between 87.2 and 97.8% and 0.73 and 0.85, respectively. This study demonstrates that swabs and biopsies tend to yield the same culture results when taken from the same location. For frequently occurring microorganisms, agreement between the two methods was even higher. Therefore, there seems to be no direct need for invasive biopsy in clinical practice.

Rapid enzyme analysis as a diagnostic tool for wound infection: Comparison between clinical judgment, microbiological analysis, and enzyme analysis.

In clinical practice, diagnosis of wound infection is based on the classical clinical signs of infection. When infection is suspected, wounds are often swabbed for microbiological culturing. These methods are not accurate (clinical judgment in chronic wounds) or provide results after several days (wound swab). Therefore, there is an urgent need for an easy-to-use diagnostic tool for fast detection of wound infection, especially in chronic wounds. This study determined the diagnostic properties of the enzymes myeloperoxidase, human neutrophil elastase (HNE), lysozyme and cathepsin-G in detecting wound infection when compared to wound swabs. Both chronic and acute wounds of 81 patients were assessed through clinical judgment, enzyme analysis and wound swab. Three promising enzyme models for detecting wound infection were identified. A positive test was defined as: at least one enzyme positive after 30 minutes (model 1), lysozyme and HNE positive after 30 minutes (model 2), myeloperoxidase positive after 5 minutes, and HNE or lysozyme positive after 30 minutes (model 3). All models were significant (p≤0.001). There was no correlation between clinical judgment and wound swab, indicating the need for novel diagnostic systems. Enzyme analysis is fast, easy to use and superior to clinical judgment when compared to wound swabs.

A Host-Directed Approach to the Detection of Infection in Hard-to-Heal Wounds.

Wound infection is traditionally defined primarily by visual clinical signs, and secondarily by microbiological analysis of wound samples. However, these approaches have serious limitations in determining wound infection status, particularly in early phases or complex, chronic, hard-to-heal wounds. Early or predictive patient-derived biomarkers of wound infection would enable more timely and appropriate intervention. The observation that immune activation is one of the earliest responses to pathogen activity suggests that immune markers may indicate wound infection earlier and more reliably than by investigating potential pathogens themselves. One of the earliest immune responses is that of the innate immune cells (neutrophils) that are recruited to sites of infection by signals associated with cell damage. During acute infection, the neutrophils produce oxygen radicals and enzymes that either directly or indirectly destroy invading pathogens. These granular enzymes vary with cell type but include elastase, myeloperoxidase, lysozyme, and cathepsin G. Various clinical studies have demonstrated that collectively, these enzymes, are sensitive and reliable markers of both early-onset phases and established infections. The detection of innate immune cell enzymes in hard-to-heal wounds at point of care offers a new, simple, and effective approach to determining wound infection status and may offer significant advantages over uncertainties associated with clinical judgement, and the questionable value of wound microbiology. Additionally, by facilitating the detection of early wound infection, prompt, local wound hygiene interventions will likely enhance infection resolution and wound healing, reduce the requirement for systemic antibiotic therapy, and support antimicrobial stewardship initiatives in wound care.

Chronic Wounds: Innovations in Diagnostics and Therapeutics.

BACKGROUND: A major global health issue is the existence of chronic wounds. Appropriate diagnosis and treatment is essential to promote wound healing and prevent further complications. Traditional methods for treatment and diagnosis of chronic wounds have shown to be of limited effectiveness. Therefore, there is a need for the development of diagnostic and therapeutic innovations in chronic wound care. OBJECTIVE: This mini-review aims to provide insight in the current knowledge of the wound healing process and the deficiencies encountered in chronic wounds, which provides a basis for the development of innovations in chronic wound care. Furthermore, promising diagnostic and therapeutic innovations will be highlighted. METHODS: Literature was searched for recent articles (=<10 years) describing the current knowledge about the wound healing process and chronic wounds. The most promising diagnostic and therapeutic innovations were gathered from articles published in the past 5 years. RESULTS/CONCLUSION: Wound healing is a well-organized process consisting of four phases: coagulation, inflammation, proliferation and wound remodelling. Chronic wounds often stagnate in the inflammatory phase and/or experience an impaired proliferative phase. This mini-review has demonstrated that increased knowledge about the processes involved in wound healing has paved the way for the development of new diagnostic tools and treatments for chronic wounds. Increased knowledge about bacterial invasion and infection in has encouraged researchers to develop diagnostic tools to help clinicians detect these phenomena appropriately and in time. Other researchers have shown that they are able to design/extract biochemical compounds that intervene in the disrupted healing processes in chronic wounds.