Systematic review on the benefit of graduated compression stockings in the prevention of venous thromboembolism in low-risk surgical patients

Objectives

The aim of this systematic review is to assess the performance of graduated compression stockings (GCS) in comparison to no venous thromboembolism (VTE) prophylaxis in the prevention of hospital-acquired thrombosis in low-risk surgical patients undergoing short-stay procedures.

Methods

Aligning with PRISMA guidelines, online databases MEDLINE and EMBASE, Cochrane Library® and trial registries were searched. Eligible articles reported the VTE rate in low-risk surgical patients either receiving GCS or no VTE prophylaxis.

Results

Narrative synthesis was performed on a single eligible article. The included study arm consisted of participants undergoing knee arthroscopy with the use of GCS alone reporting a total of 29 VTE events (4.4%), 16 of which were asymptomatic DVTs (2.4%).

Conclusion

There is a complete lack of evidence to support the use of GCS in the prevention of HAT for low-risk surgical patients. An adequately powered trial is required to provide level-IA evidence to support this practice.

Feasibility of a 3 mm arteriotomy for brachiocephalic fistula formation

BACKGROUND

The arteriovenous fistula is the modality of choice for long-term haemodialysis access. We describe the feasibility of routinely fashioning a brachiocephalic fistula utilising a 3 mm long arteriotomy in an attempt to reduce the incidence of symptomatic steal syndrome yet while maintaining satisfactory clinical outcomes.

METHODS

All patients who underwent brachiocephalic fistula formation using a routine 3 mm long arteriotomy within Hammersmith Hospital between January 2017 and March 2018 were included. Primary outcomes included primary failure, failure of maturation, secondary patency and steal syndrome.

RESULTS

Sixty-eight brachiocephalic arteriovenous fistula were fashioned utilising a 3 mm long arteriotomy during the study period. Mean age was 60.5 years with 59% having a history of diabetes mellitus. Mean followup was 368 days. Primary failure occurred in 10 (14.7%) patients. Cannulation was achieved in 67.3% of remaining fistula within 3-months, rising to 87.3% by 6-months. Primary patency at 6 and 12 months was 76% and 69%, respectively. Secondary patency at 6 and 12 months was 94% and 91%, respectively. Dialysis access steal syndrome was clinically apparent in three (4.4%) patients with all cases being managed conservatively.

CONCLUSION

A 3 mm long arteriotomy may be routinely utilised for brachiocephalic fistula creation in an attempt to limit the incidence of steal syndrome yet while maintaining clinical patency outcomes.

UK primary care survey of venous leg ulceration management and referral - Post-EVRA trial

Objective

Determine standards of referral and management of patients with venous leg ulceration in primary care after the release of the EVRA (A Randomized Trial of Early Endovenous Ablation in Venous Ulceration) study results.

Methods

An online questionnaire was disseminated over four months to professionals working within primary care.

Results

The survey received 643 responses. Of respondents, 90 (14%) had heard of the EVRA trial and 51 (8%) were familiar with the results. Of those who answered the following questions, 410 (69.1%) stated that referral to a vascular specialist must be made by the General Practitioner and 13 (2.2%) reported that they would always refer patients for secondary care assessment before the publication of EVRA. Considering the EVRA results, 128 (29%) reported that they would change practice regarding referral and would experience no barriers and 198 (45%) reported that they would like to refer earlier but is not their decision. Barriers to changing practice included local referral policies, training and time restrictions, 266 (59%) had heard of the NICE guideline (CG168) and 194 (43%) were aware of the recommendations for referral to a vascular service within two weeks for patients with an open or healed ulcer.

Conclusion

There is a considerable variation in local referral pathways for venous leg ulceration, and despite clinicians wanting to refer promptly, many primary care professionals are unable to. Unfortunately, the EVRA study alone may not change the overall practice, and work is needed to overcome barriers faced by primary care professionals.

A methodologic assessment of lymphedema clinical practice guidelines

OBJECTIVE

The objective of this review was to determine the methodologic quality of current lymphedema clinical practice guidelines (CPGs) to assist health care professionals in selecting accessible, high-quality guidance and to identify areas for improvement in future CPGs.

METHODS

MEDLINE, Embase, online CPG databases, and reference lists of included guidelines were searched up to January 31, 2020. Full-text CPGs reporting on evidence-based recommendations in lymphedema diagnosis or management in English were included. CPGs based on expert consensus, CPG summaries, or CPGs that were not freely available were excluded. Two reviewers identified eligible CPGs, extracted data, and assessed their quality independently using the Appraisal of Guidelines for Research and Evaluation II instrument. Significant scoring discrepancies were discussed with a third reviewer. An overall scaled quality score of ≥80% was the threshold to recommend guideline use.

RESULTS

Six relevant CPGs were identified. One was subsequently excluded as its full text could not be obtained. Overall, there was very good inter-reviewer reliability of scores with intraclass correlation coefficient of 0.952 (95% confidence interval, 0.921-0.974). No single CPG scored highest in all domains, with methodologic heterogeneity observed. Poor performance was noted in domain 5 (mean scaled score, 23.8% ± 17.1%) and domain 6 (22.9% ± 26.7%). No CPG achieved an overall scaled quality score of ≥80%, with the top CPG scoring 79.2%.

CONCLUSIONS

According to the defined threshold, no lymphedema CPG was considered adequate for use in clinical practice. All current lymphedema CPGs have areas for improvement with elements of methodologic quality lacking, particularly with respect to rigor of development. A structured approach, guided by the use of CPG creation tools and checklists such as the Appraisal of Guidelines for Research and Evaluation II instrument, should help CPG development groups in improving the quality of future CPGs. This is of particular importance in a complex, multidisciplinary condition such as lymphedema.

Fibrillar form of α-synuclein-specific scFv antibody inhibits α-synuclein seeds induced aggregation and toxicity

Synucleinopathies including Parkinson's disease (PD), dementia with Lewy bodies (DLB), and multiple system atrophy (MSA) are characterized by pathological accumulation of α-synuclein (α-syn). Amongst the various approaches attempting to tackle the pathological features of synucleinopathies, antibody-based immunotherapy holds much promise. However, the large size of antibodies and corresponding difficulty in crossing the blood-brain barrier has limited development in this area. To overcome this issue, we engineered single-chain variable fragments (scFvs) against fibrillar α-syn, a putative disease-relevant form of α-syn. The purified scFvs showed specific activity towards α-syn fibrils and oligomers in comparison to monomers and recognized intracellular inclusions in human post-mortem brain tissue of Lewy body disease cases, but not aged controls. In vitro studies indicated scFvs inhibit the seeding of α-syn aggregation in a time-dependent manner, decreased α-syn seed-induced toxicity in a cell model of PD, and reduced the production of insoluble α-syn phosphorylated at Ser-129 (pS129-α-syn). These results suggest that our α-syn fibril-specific scFvs recognize α-syn pathology and can inhibit the aggregation of α-syn in vitro and prevent seeding-dependent toxicity. Therefore, the scFvs described here have considerable potential to be utilized towards immunotherapy in synucleinopathies and may also have applications in ante-mortem imaging modalities.

Treatment of distal deep vein thrombosis

BACKGROUND

The treatment of distal (below the knee) deep vein thrombosis (DVT) is not clearly established. Distal DVT can either be treated with anticoagulation, or monitored with close follow-up to detect progression to the proximal veins (above the knee), which requires anticoagulation. Proponents of this monitoring strategy base their decision to withhold anticoagulation on the fact that progression is rare and most people can be spared from potential bleeding and other adverse effects of anticoagulation.

OBJECTIVES

To assess the effects of different treatment interventions for people with distal (below the knee) deep vein thrombosis (DVT).

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase and CINAHL databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 12 February 2019. We also undertook reference checking to identify additional studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) for the treatment of distal DVT.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data. We resolved disagreements by discussion. Primary outcomes of interest were recurrence of venous thromboembolism (VTE), DVT and major bleeding and follow up ranged from three months to two years. We performed fixed-effect model meta-analyses with risk ratio (RRs) and 95% confidence intervals (CIs). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We identified eight RCTs reporting on 1239 participants. Five trials randomised participants to anticoagulation for up to three months versus no anticoagulation. Three trials compared anticoagulation treatment for different time periods. Anticoagulant compared to no intervention or placebo for distal DVT treatment Anticoagulation with a vitamin K antagonist (VKA) reduced the risk of recurrent VTE during follow-up compared with participants receiving no anticoagulation (RR 0.34, 95% CI 0.15 to 0.77; 5 studies, 496 participants; I² = 3%; high-certainty evidence), and reduced the risk of recurrence of DVT (RR 0.25, 95% CI 0.10 to 0.67; 5 studies, 496 participants; I² = 0%; high-certainty evidence). There was no clear effect on risk of pulmonary embolism (PE) (RR 0.81, 95% CI 0.18 to 3.59; 4 studies, 480 participants; I² = 0%; low-certainty evidence). There was little to no difference in major bleeding with anticoagulation compared to placebo (RR 0.76, 95% CI 0.13 to 4.62; 4 studies, 480 participants; I² = 26%; low-certainty evidence). There was an increase in clinically relevant non-major bleeding events in the group treated with anticoagulants (RR 3.34, 95% CI 1.07 to 10.46; 2 studies, 322 participants; I² = 0%; high-certainty evidence). There was one death, not related to PE or major bleeding, in the anticoagulation group. Anticoagulation for three months or more compared to anticoagulation for six weeks for distal DVT treatment Three RCTs of 736 participants compared three or more months of anticoagulation with six weeks of anticoagulation. Anticoagulation with a VKA for three months or more reduced the incidence of recurrent VTE to 5.8% compared with 13.9% in participants treated for six weeks (RR 0.42, 95% CI 0.26 to 0.68; 3 studies, 736 participants; I² = 50%; high-certainty evidence). The risk for recurrence of DVT was also reduced (RR 0.32, 95% CI 0.16 to 0.64; 2 studies, 389 participants; I² = 48%; high-certainty evidence), but there was probably little or no difference in PE (RR 1.05, 95% CI 0.19 to 5.88; 2 studies, 389 participants; I² = 0%; low-certainty evidence). There was no clear difference in major bleeding events (RR 3.42, 95% CI 0.36 to 32.35; 2 studies, 389 participants; I² = 0%; low-certainty evidence) or clinically relevant non-major bleeding events (RR 1.76, 95% CI 0.90 to 3.42; 2 studies, 389 participants; I² = 1%; low-certainty evidence) between three months or more of treatment and six weeks of treatment. There were no reports for overall mortality or PE and major bleeding-related deaths.

AUTHORS' CONCLUSIONS

Our review found a benefit for people with distal DVT treated with anticoagulation therapy using VKA with little or no difference in major bleeding events although there was an increase in clinically relevant non-major bleeding when compared to no intervention or placebo. The small number of participants in this meta-analysis and strength of evidence prompts a call for more research regarding the treatment of distal DVT. RCTs comparing different treatments and different treatment periods with placebo or compression therapy, are required.

Treatment of distal deep vein thrombosis

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:

To assess the effects of different treatment interventions for people with distal (below the knee) deep vein thrombosis (DVT).

Parkinson's disease biomarkers based on α-synuclein

Parkinson's disease is the second most common neurodegenerative disorder after Alzheimer's disease and is estimated to affect approximately 1-4% of individuals aged over 60 years old. Although considerable efforts have been invested into developing disease-modifying therapies for Parkinson's disease, such efforts have been confounded by the difficulty in accurately diagnosing Parkinson's disease during life to enable accurate patient stratification for clinical trialling of candidate therapeutics. Therefore, the search for effective biomarkers that can be accurately evaluated during life with non-invasive means is a pressing issue in the field. Since the discovery of α-synuclein (α-syn) as a protein linked to a familial form of Parkinson's disease, later identified as the major protein component of the neuropathological hallmark of idiopathic Parkinson's disease, considerable interest has focused on this protein and its distinct conformers. We describe here the progress that has been made in the area of Parkinson's disease biomarker discovery with a focus on α-synuclein. In particular, we highlight the novel assays that have been employed and the increasing complexity in evaluating α-synuclein with regard to the considerable diversity of conformers that exist in the biofluids and peripheral tissues under disease conditions. "This article is part of the Special Issue Synuclein."

Improved Prognosis and Low Failure Rate with Anticoagulation as First-Line Therapy in Mesenteric Venous Thrombosis

BACKGROUND

Monotherapy with anticoagulation has been considered as first-line therapy in patients with mesenteric venous thrombosis (MVT). The aim of this study was to evaluate outcome, prognostic factors, and failure rate of anticoagulation as monotherapy, and to identify when bowel resection was needed.

METHODS

Retrospective study of consecutive patients with MVT diagnosed between 2000 and 2015.

RESULTS

The overall incidence rate of MVT was 1.3/100,000 person-years. Among 120 patients, seven died due to autopsy-verified MVT without bowel resection and 15 underwent immediate bowel resection without prior anticoagulation therapy. The remaining 98 patients received anticoagulation monotherapy, whereof 83 (85%) were treated successfully. Fifteen patients failed on anticoagulation monotherapy, of whom seven underwent bowel resection and eight endovascular therapy. Endovascular therapy was followed by bowel resection in three patients. Two late bowel resections were performed due to intestinal stricture. The 30-day mortality rate was 19.0% in the former (2000-2007) and 3.2% in the latter (2008-2015) part of the study period (p = 0.006). Age ≥75 years (OR 12.4, 95% CI [2.5-60.3]), management during the former as opposed to the latter time period (OR 8.4, 95% CI [1.3-54.7]), and renal insufficiency at admission (OR 8.0, 95% CI [1.2-51.6]) were independently associated with increased mortality in multivariable analysis.

CONCLUSIONS

Short-term prognosis in patients with MVT has improved. Contemporary data show that monotherapy with anticoagulation is an effective first choice in MVT patients.

Practical consensus recommendation on when to do BRCA testing

BRCA-mutation associated breast cancer and to future cancer risks and sensitivity to systemic therapies. Now that rapid genetic testing for BRCA1 and BRCA2 mutations is available, BRCA mutation status can be considered when making treatment and prevention decisions for BRCA testing, BRCA mutation carriers with breast cancer. Expert group used data from published literature, practical experience, and opinion of a large group of academic oncologists, to arrive at practical consensus recommendations for use by the community oncologists.

Testing for thrombophilia in mesenteric venous thrombosis - Retrospective original study and systematic review

The aim was to perform a local study of risk factors and thrombophilia in mesenteric venous thrombosis (MVT), and to review the literature concerning thrombophilia testing in MVT. Patients hospitalized for surgical or medical treatment of MVT at our center 2000-2015. A systematic review of observational studies was performed. In the local study, the most frequently identified risk factor was Factor V Leiden mutation. The systematic review included 14 original studies. The highest pooled percentage of any inherited thrombophilic factor were: Factor V Leiden mutation 9% (CI 2.9-16.1), prothrombin gene mutation 7% (CI 2.7-11.8). The highest pooled percentage of acquired thrombophilic factors were JAK2 V617F mutation 14% (CI -1.9-28.1). The wide range of frequency of inherited and acquired thrombophilic factors in different populations indicates the necessity to relate these factors to background population based data in order to estimate their overrepresentation in MVT. There is a need to develop guidelines for when and how thrombophilia testing should be performed in MVT.

Modeling microalgal flocculation and sedimentation

In this study, a combined flocculation and sedimentation model is developed. The model predicts the time needed to reach a desired concentration of microalgal suspension in a sedimentation tank. The concentration of the particles as function of the time and the position in the tank is described. The model was validated with experimental data for Ettlia texensis. The concentration changes measured in time at different heights in the sedimentation vessel corresponded well with model predictions. The model predicts that it takes 25 h to reach a final concentration of 5.2 gDW L(-1), when the initial concentration is 0.26 gDW L(-1) and the tank height is 1m. This example illustrates the use of this model for the design of the settling tank needed for pre-concentration of microalgal biomass before further dewatering.