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Lymphatic transport in patients with chronic venous insufficiency and venous leg ulcers following sequential pneumatic compression.

ABSTRACT: Recent advancements in near-infrared fluorescence lymphatic imaging (NIRFLI) technology provide opportunities for non-invasive, real-time assessment of lymphatic contribution in the etiology and treatment of ulcers. The objective of this study was to assess lymphatics in subjects with venous leg ulcers using NIRFLI and to assess lymphatic impact of a single session of sequential pneumatic compression (SPC).Following intradermal microdoses of indocyanine green (ICG) as a lymphatic contrast agent, NIRFLI was used in a pilot study to image the lymphatics of 12 subjects with active venous leg ulcers (Clinical, Etiologic, Anatomic, and Pathophysiologic [CEAP] C6). The lymphatics were imaged before and after a single session of SPC to assess impact on lymphatic function.Baseline imaging showed impaired lymphatic function and bilateral dermal backflow in all subjects with chronic venous insufficiency, even those without ulcer formation in the contralateral limb (C0 and C4 disease). SPC therapy caused proximal movement of ICG away from the active wound in 9 of 12 subjects, as indicated by newly recruited functional lymphatic vessels, emptying of distal lymphatic vessels, or proximal movement of extravascular fluid. Subjects with the longest duration of active ulcers had few visible lymphatic vessels, and proximal movement of ICG was not detected after SPC therapy.This study provides visible confirmation of lymphatic dysfunction at an early stage in the etiology of venous ulcer formation and demonstrates the potential therapeutic mechanism of SPC therapy in removing excess fluid. The ability of SPC therapy to restore fluid balance through proximal movement of lymph and interstitial fluid may explain its value in hastening venous ulcer healing. Anatomical differences between the lymphatics of longstanding and more recent venous ulcers may have important therapeutic implications.

SUBMITTER: Rasmussen JC

PROVIDER: S-EPMC4782606 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

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Project description:ImportanceExercise is recommended as an adjuvant treatment for venous leg ulceration (VLU) to improve calf muscle pump function. However, the association of exercise with VLU healing has not been properly aggregated, and the effectiveness of different exercise interventions has not been characterized.ObjectiveTo summarize the association of different exercise interventions with VLU healing when used as an adjuvant to any form of compression.Data sourcesThe Cochrane Controlled Trials Register, MEDLINE, Embase, CINAHL, PsycInfo, and SCOPUS databases were searched through October 9, 2017.Study selectionRandomized clinical trials (RCTs) of any exercise compared with no exercise in participants with VLU were included, where compression was used as standard therapy and a healing outcome was reported. Independent title screening and full text review by 2 authors (A.J., J.S.) with appeal to a third author (J.P.) if disagreement was unresolved. Of the 519 articles screened, a total of 6 (1.2%) studies met the inclusion criteria for systematic review, including 5 for meta-analysis.Data extraction and synthesisIndependent quality assessment for Cochrane risk of bias and data extraction by 2 authors with appeal to third author if disagreement unresolved (PRISMA). Data pooled using fixed effects model.Main outcomes and measuresThe a priori primary outcome was any healing outcome (proportion healed, time to healing, or change in ulcer area). Secondary outcomes (adverse events, costs, and health-related quality of life) were only collected if a primary outcome was reported.ResultsSix RCTs were identified and 5 (190 participants) met inclusion criteria for meta-analysis. The exercise interventions were progressive resistance exercise alone (2 RCTs, 53 participants) or combined with prescribed physical activity (2 RCTs, 102 participants), walking only (1 RCT, 35 participants), or ankle exercises (1 RCT, 40 participants). Overall, exercise was associated with increased VLU healing at 12 weeks although the effect was imprecise (additional 14 cases healed per 100 patients; 95% CI, 1-27 cases per 100; P = .04). The combination of progressive resistance exercise plus prescribed physical activity appeared to be most effective, again with imprecision (additional 27 cases healed per 100 patients; 95% CI, 9-45 cases per 100; P = .004).Conclusions and relevanceThe evidence base may now be sufficiently suggestive for clinicians to consider recommending simple progressive resistance and aerobic activity to suitable patients with VLU while further research is produced.

Project description:IntroductionLow-frequency, low-intensity ultrasound has been previously shown to promote healing of chronic wounds in humans, but mechanisms behind these effects are poorly understood. The purpose of this study was to evaluate gene expression differences in debrided human venous ulcer tissue from patients treated with low-frequency (20 kHz), low-intensity (100 mW/cm2) ultrasound compared to a sham treatment in an effort to better understand the potential biological mechanisms.MethodsDebrided venous ulcer tissue was collected from 32 subjects one week after sham treatment or low-frequency, low-intensity ultrasound treatment. Of these samples, 7 samples (3 ultrasound treated and 4 sham treated) yielded sufficient quality total RNA for analysis by ultra-high multiplexed PCR (Ampliseq) and expression of more than 24,000 genes was analyzed. 477 genes were found to be significantly differentially expressed between the ultrasound and sham groups using cut-off values of p < 0.05 and fold change of 2.Results and discussionThe top differentially expressed genes included those involved in regulation of cell metabolism, proliferation, and immune cell signaling. Gene set enrichment analysis identified 20 significantly enriched gene sets from upregulated genes and 4 significantly enriched gene sets from downregulated genes. Most of the enriched gene sets from upregulated genes were related to cell-cell signaling pathways. The most significantly enriched gene set from downregulated genes was the inflammatory response gene set. These findings show that therapeutic ultrasound influences cellular behavior in chronic wounds as early as 1 week after application. Considering the well-known role of chronic inflammation in impairing wound healing in chronic wounds, these results suggest that a downregulation of inflammatory genes is a possible biological mechanism of ultrasound-mediated venous chronic wound healing. Such increased understanding may ultimately lead to the enhancement of ultrasound devices to accelerate chronic wound healing and increase patient quality of life.

Project description:ObjectiveTo review the evidence of effectiveness of dressings applied to venous leg ulcers.DesignSystematic review and meta-analysis.Data sourcesHand searches of journals and searches of electronic databases, conference proceedings, and bibliographies up to April 2006; contacts with dressing manufacturers for unpublished studies.Studies reviewedAll randomised controlled trials that evaluated dressings applied to venous leg ulcers were eligible for inclusion. Data from eligible studies were extracted and summarised independently by two reviewers using a data extraction sheet. Methodological quality was assessed independently by two reviewers.ResultsThe search strategy identified 254 studies; 42 of these fulfilled the inclusion criteria. Hydrocolloids were no more effective than simple low adherent dressings used beneath compression (eight trials; relative risk for healing with hydrocolloid 1.02, 95% confidence interval 0.83 to 1.28). For other comparisons, insufficient evidence was available to allow firm conclusions to be drawn. None of the dressing comparisons showed evidence that a particular class of dressing healed more ulcers. Some differences existed between dressings in terms of subjective outcome measures and ulcer healing rates. The results were not affected by the size or quality of trials or the unit of randomisation. Insufficient data were available to allow conclusions to be drawn about the relative cost effectiveness of different dressings.ConclusionsThe type of dressing applied beneath compression was not shown to affect ulcer healing. The results of the meta-analysis showed that applying hydrocolloid dressings beneath compression produced no benefit in terms of ulcer healing compared with applying simple low adherent dressings. No conclusive recommendations can be made as to which type of dressing is most cost effective. Decisions on which dressing to apply should be based on the local costs of dressings and the preferences of the practitioner or patient.

Project description:IntroductionLeg immobilisation in a cast or an orthosis after lower limb injuries is associated with a high risk of complications of venous thromboembolism (VTE) and hampered healing. Current pharmacoprophylaxes of VTE are inefficient and associated with adverse events. Intermittent pneumatic compression (IPC) could represent a novel, efficient and safe VTE-prophylactic alternative that may enhance injury healing. The aim of STOP leg clots is to assess the efficacy of adjuvant IPC-therapy on reduction of VTE incidence and improvement of healing in lower leg immobilised outpatients.Methods and analysisSTOP leg clots is a multicentre randomised controlled superiority trial. Eligible patients (700 patients/arm) with either an acute ankle fracture or Achilles tendon rupture will be randomised to either addition of IPC during lower-leg immobilisation or to treatment-as-usual. The primary outcome will be the total VTE incidence, that is, symptomatic and asymptomatic deep venous thrombosis (DVT) or symptomatic pulmonary embolism (PE), during the leg immobilisation period, approximately 6-8 weeks. DVT incidence will be assessed by screening whole leg compression duplex ultrasound at removal of leg immobilisation and/or clinically diagnosed within the time of immobilisation. Symptomatic PE will be verified by CT.Secondary outcomes will include patient-reported outcome using validated questionnaires, healing evaluated by measurements of tendon callus production and changes in VTE-prophylactic mechanisms assessed by blood flow and fibrinolysis. Data analyses will be blinded and based on the intention-to-treat.Ethics and disseminationEthical approval was obtained by the ethical review board in Stockholm, Sweden, Dnr 2016/1573-31. The study will be conducted in accordance with the Helsinki declaration. The results of the study will be disseminated in peer-reviewed international journals.Trial registrationNCT03259204.Time schedule1 September 2018 to 31 December 2022.

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Lymphatic transport in patients with chronic venous insufficiency and venous leg ulcers following sequential pneumatic compression.

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