Randomized clinical trial of low molecular weight heparin with thigh-length or knee-length antiembolism stockings for patients undergoing surgery

An Updated Systematic Review and Meta-analysis of the Impact of Graduated Compression Stockings in Addition to Pharmacological Thromboprophylaxis for Prevention of Venous Thromboembolism in Surgical Inpatients

OBJECTIVE

To compare the rate of venous thromboembolism (VTE) in surgical inpatients with pharmacological thromboprophylaxis and additional graduated compression stockings (GCSs) versus pharmacological thromboprophylaxis alone.

BACKGROUND

Surgical inpatients have elevated VTE risk; recent studies cast doubt on whether GCS confers additional protection against VTE, compared with pharmacological thromboprophylaxis alone.

METHODS

The review followed "Preferred Reporting Items for Systematic Reviews and Meta-analyses" guidelines using a registered protocol (CRD42017062655). The MEDLINE and Embase databases were searched up to November 2022. Randomized trials reporting VTE rate after surgical procedures, utilizing pharmacological thromboprophylaxis, with or without GCS, were included. The rates of deep venous thrombosis (DVT), pulmonary embolism, and VTE-related mortality were pooled through fixed and random effects.

RESULTS

In a head-to-head meta-analysis, the risk of DVT for GCS and pharmacological thromboprophylaxis was 0.85 (95% CI: 0.54-1.36) versus for pharmacological thromboprophylaxis alone (2 studies, 70 events, 2653 participants). The risk of DVT in pooled trial arms for GCS and pharmacological thromboprophylaxis was 0.54 (95% CI: 0.23-1.25) versus pharmacological thromboprophylaxis alone (33 trial arms, 1228 events, 14,108 participants). The risk of pulmonary embolism for GCS and pharmacological prophylaxis versus pharmacological prophylaxis alone was 0.71 (95% CI: 0.0-30.0) (27 trial arms, 32 events, 11,472 participants). There were no between-group differences in VTE-related mortality (27 trial arms, 3 events, 12,982 participants).

CONCLUSIONS

Evidence from head-to-head meta-analysis and pooled trial arms demonstrates no additional benefit for GCS in preventing VTE and VTE-related mortality. GCS confer a risk of skin complications and an economic burden; current evidence does not support their use for surgical inpatients.

Graduated compression stockings for the prevention of deep-vein thrombosis in postoperative surgical patients: a systematic review and economic model with a value of information analysis

BACKGROUND

Deep-vein thrombosis (DVT) can occur in surgical patients. Routine prophylaxis can be pharmacological and/or mechanical [e.g. graduated compression stockings (GCSs)]. GCSs are available in knee length or thigh length.

OBJECTIVE

To establish the expected value of undertaking additional research addressing the relative effectiveness of thigh-length GCSs versus knee-length GCSs, in addition to pharmacoprophylaxis, for prevention of DVT in surgical patients.

DESIGN

Systematic review and economic model, including value of information (VOI) analysis.

REVIEW METHODS

Randomised controlled trials (RCTs) assessing thigh- or knee-length GCSs in surgical patients were eligible for inclusion. The primary outcome was incidence of DVT. DVT complications and GCSs adverse events were assessed. Random-effects meta-analysis was performed. To draw on a wider evidence base, a random-effects network meta-analysis (NMA) was undertaken for the outcome DVT. A review of trials and observational studies of patient adherence was also conducted. A decision-analytic model was developed to assess the cost-effectiveness of thigh- and knee-length GCSs and the VOI.

RESULTS

Twenty-three RCTs were included in the review of effectiveness. There was substantial variation between trials in terms of the patient characteristics, interventions and methods of outcome assessment. Five trials comparing knee-length with thigh-length GCSs with or without pharmacoprophylaxis were pooled; the summary estimate of effect indicated a non-significant trend favouring thigh-length GCSs [odds ratio (OR) 1.48, 95% confidence interval (CI) 0.80 to 2.73]. Thirteen trials were included in the NMA. In the base-case analysis, thigh-length GCSs with pharmacoprophylaxis were more effective than knee-length GCSs with pharmacoprophylaxis (knee vs. thigh OR 1.76, 95% credible interval 0.82 to 3.53). Overall, thigh-length stockings with pharmacoprophylaxis was the most effective treatment, with a 0.73 probability of being the most effective treatment in a new trial of all the treatments. Patient adherence was generally higher with knee-length GCSs, and patients preferred knee-length GCSs. Thigh-length GCSs were found to be cost-effective in all but the subgroup with the lowest baseline risk, although the absolute differences in costs and effects were relatively small. The expected value of perfect information ranged from £0.2M to £178.0M depending on the scenario and subgroup. The relative effect parameters had the highest expected value of partial perfect information and ranged from £2.0M to £39.4M. The value of further research was most evident in the high-risk subgroups.

LIMITATIONS

There was substantial variation across the included trials in terms of patient and intervention characteristics. Many of the included trials were old and poorly reported, which reduces the reliability of the results of the review.

CONCLUSIONS

Given that the results from both the standard meta-analysis and the NMA lacked precision (CIs were wide) owing to the heterogeneous evidence base, a new definitive trial in high-risk patients may be warranted. However, the efficiency of any further research (i.e. whether this represents value for money) is dependent on several factors, including the acquisition price of GCSs, expected compliance with thigh-length GCSs wear, and whether or not uncertainty can be resolved around possible effect modifiers, as well as the feasibility and actual cost of undertaking the proposed research.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42014007202.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Thigh length versus knee length antiembolism stockings for the prevention of deep vein thrombosis in postoperative surgical patients; a systematic review and network meta-analysis

OBJECTIVES

To assess the clinical effectiveness of thigh length versus knee length antiembolism stockings for the prevention of deep vein thrombosis (DVT) in surgical patients.

DESIGN

Systematic review and meta-analysis using direct methods and network meta-analysis.

METHODS

Previous systematic reviews and electronic databases were searched to February 2014 for randomised controlled trials (RCTs) of thigh length or knee length antiembolism stockings in surgical patients. Study quality was assessed using the Cochrane Risk of Bias Tool. The primary outcome was incidence of DVT. Analysis of the DVT data was performed using ORs along with 95% CIs. The I(2) statistic was used to quantify statistical heterogeneity.

RESULTS

23 RCTs were included; there was substantial variation between the trials and many were poorly reported with an unclear risk of bias. Five RCTs directly comparing thigh length versus knee length stockings were pooled and the summary estimate of effect favouring thigh length stockings was not statistically significant (OR 1.48, 95% CI 0.80 to 2.73). 13 RCTs were included in the network meta-analysis; thigh length stockings with pharmacological prophylaxis were more effective than knee length stockings with pharmacological prophylaxis, but again results were not statistically significant (OR 1.76, 95% credible intervals 0.82 to 3.53).

CONCLUSIONS

Thigh length stockings may be more effective than knee length stockings, but results did not reach statistical significance and the evidence base is weak. Further research to confirm this finding is unlikely to be worthwhile. While thigh length stockings appear to have superior efficacy, practical issues such as patient acceptability may prevent their wide use in clinical practice.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42014007202.

The Prevention of Venous Thromboembolism in Surgical Patients

Patients undergoing surgery are at an increased risk of VTE. Since the early 1990s the prevention of VTE has been dominated by the administration of low-molecular weight heparin during admission. New oral anticoagulants have been extensively researched and have increased in popularity. This chapter reviews why surgical patients are at increased risk of VTE and summaries both the pharmacological and mechanical methods of prophylaxis available.

A randomised clinical trial comparing the patient comfort and efficacy of three different graduated compression stockings in the prevention of postoperative deep vein thrombosis

AIMS AND OBJECTIVES

To compare the comfort levels of patients regarding the use of three different graduated compression stockings and to analyse the efficacies of the graduated compression stockings in relation to patient comfort and compliance in prevention of postoperative deep vein thrombosis.

BACKGROUND

Graduated compression stockings are very important with other prophylaxis methods in postoperative deep vein thrombosis prophylaxis. In meta-analyses and systematic review studies, it was reported that knee-length and thigh-length graduated compression stockings had similar efficacies. However, there is no randomised study in literature regarding the patient problems and levels of comfort with the use of graduated compression stockings of different sizes and pressures.

DESIGN

A randomised clinical trial design.

METHODS

A total of 219 patients were randomised into three groups (n = 73 in each group). Group I was given low-pressure, knee-length graduated compression stockings, group II was given low-pressure, thigh-length graduated compression stockings and group III was given moderate-pressure, knee-length graduated compression stockings. The level of patients comfort regarding the graduated compression stockings and occurrence of deep vein thrombosis were examined.

RESULTS

The vast majority of the patients (79·5%) in group III and 52·1% of the patients in group II stated experiencing problems during the use of the graduated compression stockings (p < 0·001). The graduated compression stockings were reported by the patients as being very comfortable in the group I (p < 0·001). No findings of thrombosis were observed in any of the groups.

CONCLUSION

The low-pressure, knee-length graduated compression stockings are as effective as the other graduated compression stockings of different pressures and sizes in the postoperative deep vein thrombosis prophylaxis, and the patients have fewer problems while using these graduated compression stockings with a high satisfaction.

RELEVANCE TO CLINICAL PRACTICE

The combined use of pharmacological, mechanical and physical methods and patient education is effective in the prevention of postoperative deep vein thrombosis. The use of low-pressure, knee-length graduated compression stockings in clinical practice may be recommended, as the patients have fewer problems while using these graduated compression stockings with a high satisfaction.

The additional benefit of graduated compression stockings to pharmacologic thromboprophylaxis in the prevention of venous thromboembolism in surgical inpatients

OBJECTIVE

The evidence base supporting the use of graduated compression stockings (GCS) for venous thromboembolism (VTE) prevention has been challenged, and there appears to be a lack of evidence for the additional benefit of GCS to pharmacologic thromboprophylaxis. This study aimed to summarize and quality assess the existing evidence concerning whether GCS offer a significant benefit in addition to pharmacologic thromboprophylaxis in surgical inpatients.

METHODS

A systematic review of published literature was performed. Inclusion criteria were (1) randomized controlled trials (RCTs), (2) surgical inpatients, (3) study arms examining prophylactic-dose pharmacologic thromboprophylaxis alone or in conjunction with GCS, and (4) outcome of VTE.

RESULTS

In the review, 1025 articles were screened, of which 27 RCTs were included. Six RCT study arms included patients with GCS in conjunction with pharmacologic thromboprophylaxis, whereas 22 RCT study arms included patients treated with pharmacologic thromboprophylaxis alone. One RCT had both of its study arms included in the systematic review. The total number of patients that received pharmacologic thromboprophylaxis alone was 12,481. Of these patients, 1292 (10.4%) suffered VTE. The total number of patients that received GCS in conjunction with pharmacologic thromboprophylaxis was 1283. Of these patients, 75 had VTE (5.8%). Heterogeneity analysis demonstrated that the results of included study arms were significantly heterogeneous, precluding a valid summation analysis.

CONCLUSIONS

The additional benefit of GCS to pharmacologic thromboprophylaxis in surgical inpatients is not clear on the basis of existing data. Further clinical trials directly evaluating this clinical question are recommended.

Review article: Anti-embolism stockings

The National Institute for Health and Clinical Excellence (NICE) guidelines recommend combined mechanical and pharmacological prophylaxis to reduce the risk of venous thromboembolism (VTE) in patients undergoing orthopaedic surgery. There is increasing evidence that anti-embolic stockings (AES) have little effect on reducing such risk. Articles in the MEDLINE, EMBASE, and Cochrane Library were reviewed. Studies on the use of pharmacological prophylaxis recommended in the 2010 NICE guidelines including low-molecular-weight heparin, unfractionated heparin, rivaroxaban, and dabigatran with and without AES in patients undergoing orthopaedic surgery were included. A total of 1171 trauma and elective orthopaedic patients in 4 studies were included; 587 received pharmacological prophylaxis alone, and 584 received a combination of pharmacological prophylaxis and above- or belowknee AES. Of the respective patients, 44 (7.5%) and 31 (5.3%) developed deep vein thrombosis (p=0.1587) and 7 (1.2%) and 9 (1.5%) developed pulmonary embolism (p=0.8493). The overall VTE rates did not differ significantly (p=0.2864). No death from VTE was reported. Addition of AES did not confer significant benefit in terms of reducing the risk of VTE in orthopaedic patients.

Knee length versus thigh length graduated compression stockings for prevention of deep vein thrombosis in postoperative surgical patients

BACKGROUND

Graduated compression stockings (GCS) are a valuable means of thromboprophylaxis in hospitalised postoperative surgical patients. But it is still unclear whether knee length graduated compression stockings (KL) or thigh length (TL) stockings are more effective.

OBJECTIVES

The aim of this review was to systematically analyse the randomised, controlled trials that have evaluated the effectiveness of KL versus TL GCS as a thromboprophylaxis tool in hospitalised patients undergoing various types of surgery.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched February 2012) and CENTRAL (2012, Issue 1). The authors searched MEDLINE and EMBASE (until 27 February 2012) and they also searched the reference lists of relevant articles to identify additional trials.

SELECTION CRITERIA

Randomised controlled trials published in any language on KL versus TL GCS used as a thromboprophylaxis tool in hospitalised patients of any age and either gender.

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two review authors using data extraction sheets and confirmed by the third review author.

MAIN RESULTS

Three studies, with a combined total of 496 patients, matched the inclusion criteria for this review. All three included studies evaluated the role of KL and TL in thromboprophylaxis among a group of postoperative patients. These studies showed no significant difference in the ability of the two modalities of leg compression to reduce the incidence of deep vein thrombosis in postoperative patients. In both the fixed-effect model (odds ratio (OR) 1.55, 95% confidence interval (CI) 0.78 to 3.07, P = 0.21) and random-effects model (OR 1.32, 95% CI 0.43 to 4.06, P = 0.63) KL graduated compression stockings were as effective as TL stockings in thromboprophylaxis. However, there was significant heterogeneity (Tau(2) = 0.50; Chi(2) = 4.12, df = 2 (P = 0.13); I(2) = 51%) among trials. Results of this review may be considered weak because there was significant heterogeneity among included trials resulting from inadequate randomisation techniques, allocation concealment, power calculations and the absence of intention-to-treat analysis.

AUTHORS' CONCLUSIONS

This review found that there is insufficient high quality evidence to determine whether or not KL and TL GCS differ in their effectiveness in terms of reducing the incidence of deep vein thrombosis (DVT) in hospitalised patients.  A major multicentre RCT is required to address this issue. In the meantime, the decision on which type of stocking to use in clinical practice is likely to be influenced by factors such as patient compliance, ease of use and cost implications.

Knee versus Thigh Length Graduated Compression Stockings for Prevention of Deep Venous Thrombosis: A Systematic Review

OBJECTIVE

Graduated compression stockings are a valuable means of thrombo-prophylaxis but it is unclear whether knee-length (KL) or thigh length (TL) stockings are more effective. The aim of this review was to systematically analyse randomised controlled trials that have evaluated stocking length and efficacy of thromboprophylaxis.

METHOD

A systematic review of the literature was undertaken. Clinical trials on hospitalised populations and passengers on long haul flights were selected according to specific criteria and analysed to generate summated data.

RESULTS

14 randomized control trials were analysed. Thirty six of 1568 (2.3%) participants randomised to KL stockings developed a deep venous thrombosis, compared with 79 of 1696 (5%) in the TL control/thigh length group. Substantial heterogeneity was observed amongst trials. KL stockings had a significant effect to reduce the incidence of DVT in long haul flight passengers, odds ration 0.08 (95%CI 0.03-0.22). In hospitalised patients KL stockings did not appear to be far worse than TL stockings, odds ratio 1.01 (95%CI 0.35-2.90). For combined passengers and patients, there was a benefit in favour of KL stockings, weighted odds ratio 0.45 (95% CI 0.30-0.68).

CONCLUSION

KL graduated stockings can be as effective as TL stockings for the prevention of DVT, whilst offering advantages in terms of patient compliance and cost.

Prevention of postoperative venous thromboembolism. Risk assessment and methods of prophylaxis

PURPOSE

To describe risk assessment models that have been developed to stratify patients into different risk levels of postoperative venous thromboembolism (VTE) and then to review the different methods of prophylaxis and to outline the evidence supporting their effectiveness and safety.

SOURCE

Our review of the literature is focused on consensus documents, recent large randomized trials and meta-analyses.

PRINCIPAL FINDINGS

The risk of VTE is determined by the type of surgery and underlying patient factors. Risk assessment models are useful in stratifying patients into different VTE risk levels. However, multiple risk factors are often present in the same patient and in practice the evaluation of their relative contribution to the overall risk remains difficult. A variety of prophylactic strategies including physical and pharmacological methods have been shown to be effective in different patient groups. Patients with a moderate or high risk of VTE should receive prophylaxis consisting of an antithrombotic agent, unless contraindicated, used alone or in combination with a mechanical method. Recommendations concerning which prophylaxis to use and how intensive it should be are based mainly on data from trials using surrogate endpoints, and do not translate easily into practical decisions aiming to reduce the incidence of symptomatic events.

CONCLUSION

Although risk assessment models and recommendations provided by consensus documents are of practical assistance, a decision concerning any patient is best made by combining recommendations of the literature with clinical judgment, including individual patient risk factors for thrombosis and bleeding.