Study protocol for a multicentre, randomised controlled trial to compare the use of the decellularised dermis allograft in addition to standard care versus standard care alone for the treatment of venous leg ulceration: DAVE trial.

INTRODUCTION: Venous leg ulceration (VLU), the most common type of chronic ulcer, can be difficult to heal and is a major cause of morbidity and reduced quality of life. Although compression bandaging is the principal treatment, it is time-consuming and bandage application requires specific training. There is evidence that intervention on superficial venous incompetence can help ulcer healing and recurrence, but this is not accessible to all patients. Hence, new treatments are required to address these chronic wounds. One possible adjuvant treatment for VLU is human decellularised dermis (DCD), a type of skin graft derived from skin from deceased tissue donors. Although DCD has the potential to promote ulcer healing, there is a paucity of data for its use in patients with VLU. METHODS AND ANALYSIS: This is a multicentre, parallel group, pragmatic randomised controlled trial. One hundred and ninety-six patients with VLU will be randomly assigned to receive either the DCD allograft in addition to standard care or standard care alone. The primary outcome is the proportion of participants with a healed index ulcer at 12 weeks post-randomisation in each treatment arm. Secondary outcomes include the time to index ulcer healing and the proportion of participants with a healed index ulcer at 12 months. Changes in quality of life scores and cost-effectiveness will also be assessed. All analyses will be carried out on an intention-to-treat (ITT) basis. A mixed-effects, logistic regression on the outcome of the proportion of those with the index ulcer healed at 12 weeks will be performed. Secondary outcomes will be assessed using various statistical models appropriate to the distribution and nature of these outcomes. ETHICS AND DISSEMINATION: Ethical approval was granted by the Bloomsbury Research Ethics Committee (19/LO/1271). Findings will be published in a peer-reviewed journal and presented at national and international conferences. TRIAL REGISTRATION NUMBER: ISRCTN21541209.

Compression stockings in addition to low-molecular-weight heparin to prevent venous thromboembolism in surgical inpatients requiring pharmacoprophylaxis: the GAPS non-inferiority RCT.

BACKGROUND: Patients admitted to hospital for surgery are at an increased risk of venous thromboembolism. Pharmaco-thromboprophylaxis and mechanical prophylaxis (usually graduated compression stockings or intermittent pneumatic compression) have been shown to reduce the incidence of venous thromboembolism. The evidence base supporting the National Institute for Health and Care Excellence's recommendation for the use of graduated compression stockings for venous thromboembolism prevention in the UK has recently been challenged. It is unclear if the risks and costs associated with graduated compression stockings are justified for deep-vein thrombosis prevention in moderate- and high-risk elective surgical inpatients receiving low-dose low-molecular-weight heparin pharmaco-thromboprophylaxis. OBJECTIVES: The primary objective was to compare the venous thromboembolism rate in elective surgical inpatients at moderate or high risk of venous thromboembolism who were receiving either graduated compression stockings and low-dose low-molecular-weight heparin (standard care) or low-dose low-molecular-weight heparin alone (intervention). DESIGN: This was a pragmatic, multicentre, prospective, non-inferiority, randomised controlled trial. SETTING: This took place in secondary care NHS hospitals in the UK. PARTICIPANTS: Patients aged ≥ 18 years who were assessed to be at moderate or high risk of venous thromboembolism according to the NHS England venous thromboembolism risk assessment tool (or the trust equivalent based on this form) and who were not contraindicated to low-molecular-weight heparin or graduated compression stockings were deemed eligible to take part. INTERVENTIONS: Participants were randomised 1 : 1 to either low-molecular-weight heparin or low-molecular-weight heparin and graduated compression stockings. MAIN OUTCOME MEASURES: The primary outcome measure was venous thromboembolism up to 90 days after surgery. A combined end point of duplex ultrasound-proven new lower-limb deep-vein thrombosis (symptomatic or asymptomatic) plus imaging-confirmed symptomatic pulmonary embolism. Secondary outcomes included quality of life, compliance with graduated compression stockings and low-molecular-weight heparin during admission, and all-cause mortality. RESULTS: A total of 1905 participants were randomised and 1858 were included in the intention-to-treat analysis. A primary outcome event occurred in 16 out of 937 (1.7%) patients in the low-molecular-weight heparin-alone arm compared with 13 out of 921 (1.4%) patients in the low-molecular-weight heparin plus graduated compression stockings arm. The risk difference between low-molecular-weight heparin and low-molecular-weight heparin plus graduated compression stockings was 0.30% (95% confidence interval -0.65% to 1.26%). As the 95% confidence interval did not cross the non-inferiority margin of 3.5% (p < 0.001 for non-inferiority), the results indicate that non-inferiority of low-molecular-weight heparin alone was shown. LIMITATIONS: In total, 13% of patients did not receive a duplex ultrasound scan that could have detected further asymptomatic deep-vein thrombosis. However, missing scans were balanced between both trial arms. The subpopulation of those aged ≥ 65 years assessed as being at a moderate risk of venous thromboembolism was under-represented in the study; however, this reflects that this group is under-represented in the general population. CONCLUSIONS: For elective surgical patients at moderate or high risk of venous thromboembolism, administration of pharmaco-thromboprophylaxis alone is non-inferior to a combination of pharmaco-thromboprophylaxis and graduated compression stockings. These findings indicate that graduated compression stockings may be unnecessary for most elective surgical patients. FUTURE WORK: Further studies are required to evaluate whether or not adjuvant graduated compression stockings have a role in patients receiving extended thromboprophylaxis, beyond the period of hospital admission, following elective surgery or in patients undergoing emergency surgical procedures. TRIAL REGISTRATION: Current Controlled Trials ISRCTN13911492. FUNDING: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 69. See the NIHR Journals Library website for further project information.

WHY DID WE CONDUCT THIS RESEARCH?: People undergoing operations are at risk of developing blood clots in their legs, which is known as a deep-vein thrombosis. Blood clots occur for several reasons, such as not being able to move around after an operation, changes in the blood or damage to the veins in which blood travels. To decrease the risk of getting deep-vein thrombosis, patients having operations are given tight elastic socks to wear called graduated compression stockings. They are also given blood thinning medicine to prevent clotting. There is little evidence that wearing elastic socks in hospital will reduce the risk of blood clots if blood thinners are also given. Many patients say that the socks can hurt or cause bruising and can be difficult to put on. The graduated compression as an adjunct to thromboprophylaxis in surgery (GAPS) trial investigated whether or not patients having an operation would benefit from wearing elastic socks as well as getting blood thinners, or if blood thinners on their own prevented blood clots. WHAT DID WE DO?: A total of 1905 patients who were having operations at seven hospitals in England agreed to take part. They were randomly assigned to different treatments by a computer program. Half of the patients were given elastic socks plus blood thinners, and the other half were given the blood thinners alone. WHAT DID WE FIND?: There was no significant difference in the number of people who had a blood clot in either study group. This could mean that blood thinners are as good at stopping blood clots as blood thinners and elastic socks for patients having operations. WHAT COULD BE CARRIED OUT NEXT?: The NHS spends around £63M per year across England on elastic stockings. This research indicates that patients might not get extra benefit from wearing them if they have taken blood thinners.

Graduated compression stockings as adjuvant to pharmaco-thromboprophylaxis in elective surgical patients (GAPS study): randomised controlled trial.

OBJECTIVES: To investigate whether the use of graduated compression stockings (GCS) offers any adjuvant benefit when pharmaco-thromboprophylaxis is used for venous thromboembolism prophylaxis in patients undergoing elective surgery. DESIGN: Open, multicentre, randomised, controlled, non-inferiority trial. SETTING: Seven National Health Service tertiary hospitals in the United Kingdom. PARTICIPANTS: 1905 elective surgical inpatients (≥18 years) assessed as being at moderate or high risk of venous thromboembolism were eligible and consented to participate. INTERVENTION: Participants were randomly assigned (1:1) to receive low molecular weight heparin (LMWH) pharmaco-thromboprophylaxis alone or LMWH pharmaco-thromboprophylaxis and GCS. OUTCOME MEASURES: The primary outcome was imaging confirmed lower limb deep vein thrombosis with or without symptoms, or pulmonary embolism with symptoms within 90 days of surgery. Secondary outcome measures were quality of life, compliance with stockings and LMWH, lower limb complications related to GCS, bleeding complications, adverse reactions to LMWH, and all cause mortality. RESULTS: Between May 2016 and January 2019, 1905 participants were randomised. 1858 were included in the intention to treat analysis (17 were identified as ineligible after randomisation and 30 did not undergo surgery). A primary outcome event occurred in 16 of 937 (1.7%) patients in the LMWH alone group compared with 13 of 921 (1.4%) in the LMWH and GCS group. The risk difference between the two groups was 0.30% (95% confidence interval -0.65% to 1.26%). Because the 95% confidence interval did not cross the non-inferiority margin of 3.5% (P<0.001 for non-inferiority), LMWH alone was confirmed to be non-inferior. CONCLUSIONS: For patients who have elective surgery and are at moderate or high risk of venous thromboembolism, administration of pharmaco-thromboprophylaxis alone is non-inferior to a combination of pharmaco-thromboprophylaxis and GCS. These findings indicate that GCS might be unnecessary in most patients undergoing elective surgery. TRIAL REGISTRATION: ISRCTN13911492.