In vitro Activity of Antimicrobial Wound Dressings on P. aeruginosa Wound Biofilm.

The treatment of acute and chronic infected wounds with residing biofilm still poses a major challenge in medical care. Interactions of antimicrobial dressings with bacterial load, biofilm matrix and the overall protein-rich wound microenvironment remain insufficiently studied. This analysis aimed to extend the investigation on the efficacy of a variety of antimicrobial dressings using an in vitro biofilm model (lhBIOM) mimicking the specific biofilm-environment in human wounds. Four wound dressings containing polyhexanide (PHMB), octendine di-hydrochloride (OCT), cadexomer-iodine (C-IOD) or ionic silver (AG) were compared regarding their antimicrobial efficacy. Quantitative analysis was performed using a quantitative suspension method, separately assessing remaining microbial counts within the solid biofilm as well as the dressing eluate (representing the absorbed wound exudate). Dressing performance was tested against P. aeruginosa biofilms over the course of 6 days. Scanning electron microscopy (SEM) was used to obtain qualitative visualization on changes in biofilm structure. C-IOD demonstrated superior bacterial reduction. In comparison it was the only dressing achieving a significant reduction of more than 7 log10 steps within 3 days. Neither the OCT- nor the AG-containing dressing exerted a distinct and sustained antimicrobial effect. PHMB achieved a non-significant microbicidal effect (1.71 ± 0.31 log10 steps) at day 1. Over the remaining course (6 days) it demonstrated a significant microbistatic effect compared to OCT, AG and the control. Quantitative results in the dressing eluate correlate with those of the solid biofilm model. Overall, AG- and OCT-containing dressings did not achieve the expected anti-biofilm efficacy, while C-IOD performed best. Chemical interaction with the biofilms extrapolymeric substance (EPS), visualized in the SEM, and dressing configuration (agent concentration and release pattern) are suspected to be responsible. The unexpected low and diverse results of the tested antimicrobial dressings indicate a necessity to rethink non-debridement anti-biofilm therapy. Focussing on the combination of biofilm-disruptive (for EPS structure) and antimicrobial (for residing microorganisms) features, as with C-IOD, using dehydration and iodine, appears reasonably complementary and an optimal solution, as suggested by the here presented in vitro data.

Right brachial access is safe for branched endovascular aneurysm repair in complex aortic disease.

BACKGROUND: The risk of perioperative cerebrovascular events in endovascular repair of thoracic and thoracoabdominal aneurysms is reported from 2% to 15%. The unavoidable use of an upper extremity access during branched endovascular aneurysm repair (b-EVAR) may play a role in embolic brain injuries. For this reason, some advocate the use of a left-sided upper access to avoid crossing the origin of supra-aortic vessels. However, the assumption that right brachial access has a higher risk for stroke during b-EVAR has not been confirmed in the literature. METHODS: This study retrospectively analyzed all consecutive patients treated by b-EVAR with right brachial access at a single institution. A through-and-through right-brachiofemoral 0.014-inch wire was used to stabilize the sheath across the arch in all cases. End point of the study was the incidence of cerebrovascular events. RESULTS: We identified 61 patients (65.6% male) during a 4-year period. Mean age at the time of surgery was 70.4 years (range, 53-87 years). The most common indication for treatment was type II (32.8%), followed by type IV thoracoabdominal aortic aneurysms (23%). There were 20 urgent (32.8%) and 41 elective (67.2%) procedures. Two perioperative ischemic strokes occurred in the first postoperative day in two men (3.3%; 95% confidence interval, 0.397-11.84). No further ischemic strokes occurred perioperatively. There was no statistically significant association between the occurrence of postoperative stroke and any of the perioperative characteristics. No significant association was found between the duration of the procedure and the end point. In both patients with embolic events, the use of a left arm approach would not have been feasible due to coverage of the left subclavian artery ostium. CONCLUSIONS: The postoperative stroke rate in b-EVAR with the use of a right brachial access in our experience was in line with the literature for treatment of thoracic and thoracoabdominal aortic aneurysms. We conclude that the right brachial access with the use of a stabilizing through-and-through wire is a safe approach during b-EVAR.

Registry and health insurance claims data in vascular research and quality improvement.

The expansion of procedures in multidisciplinary vascular medicine has sparked a controversy regarding measures of quality improvement. In addition to primary registries, the use of health insurance claims data is becoming of increasing importance. However, due to the fact that health insurance claims data are not collected for scientific evaluation but rather for reimbursement purposes, meticulous validation is necessary before and during usage in research and quality improvement matters. This review highlights the advantages and disadvantages of such data sources. A recent comprehensive expert opinion panel examined the use of health insurance claims data and other administrative data sources in medicine. Results from several studies concerning the validity of administrative data varied significantly. Validity of these data sources depends on the clinical relevance of the diagnoses considered. The rate of implausible information was 0.04 %, while the validity of the considered diagnoses varied between 80 and 97 % across multiple validation studies. A matching study between health insurance claims data of the third-largest German health insurance provider, DAK-Gesundheit, and a prospective primary registry of the German Society for Vascular Surgery demonstrated a good level of validity regarding the mortality of endovascular and open surgical treatment of abdominal aortic aneurysm in German hospitals. In addition, a large-scale international comparison of administrative data for the same disorder presented important results in treatment reality, which differed from those from earlier randomized controlled trials. The importance of administrative data for research and quality improvement will continue to increase in the future. When discussing the internal and external validity of this data source, one has to distinguish not only between its intended usage (research vs. quality improvement), but also between the included diseases and/or treatment procedures. Linkage between primary registry data and administrative data could be a reasonable solution to some current major issues of validity.
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