Is routine chemical thromboprophylaxis after total hip replacement really necessary in a Japanese population?

Efficacy of 11 anticoagulants for the prevention of venous thromboembolism after total hip or knee arthroplasty: A systematic review and network meta-analysis

BACKGROUND

To systematically review the efficacy of 11 anticoagulants in the treatment of venous thromboembolism (VTE) after total hip or knee arthroplasty.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, Wanfang Data, VIP, and China Biology Medicine databases were electronically searched for studies assessing the efficacy of different anticoagulants for the prevention of VTE after total hip or knee arthroplasty from January 1, 2010, to January 27, 2022. Two reviewers independently screened the literature, extracted data, and graded the evidence using Confidence in Network Meta-Analysis. The network meta-analysis was then performed using Stata 16.0 software and R 4.1.0 software.

RESULTS

A total of 61 articles were included. The results of network meta-analysis showed that apixaban, edoxaban, fondaparinux, rivaroxaban, and darexaban were the most effective anticoagulants for the prevention of deep vein thrombosis in patients undergoing total hip or knee arthroplasty (P < .05), while there was no difference in the efficacy among the anticoagulants for the prevention of pulmonary embolism (P > .05).

CONCLUSION

Apixaban, edoxaban, fondaparinux, rivaroxaban, and darexaban have the best efficacy for the prevention of VTE after total hip or knee arthroplasty.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism

BACKGROUND

It is generally assumed by practitioners and guideline authors that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) or pulmonary embolism (PE), or both. This is the second update of the review first published in 2008.

OBJECTIVES

The aim of this review was to assess the efficacy of combined intermittent pneumatic leg compression (IPC) and pharmacological prophylaxis compared to single modalities in preventing VTE.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and AMED databases, and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 18 January 2021. We searched the reference lists of relevant articles for additional studies.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) or controlled clinical trials (CCTs) of combined IPC and pharmacological interventions used to prevent VTE compared to either intervention individually.

DATA COLLECTION AND ANALYSIS

We independently selected studies, applied Cochrane's risk of bias tool, and extracted data. We resolved disagreements by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity. We assessed the certainty of the evidence using GRADE. The outcomes of interest were PE, DVT, bleeding and major bleeding.

MAIN RESULTS

We included a total of 34 studies involving 14,931 participants, mainly undergoing surgery or admitted with trauma. Twenty-five studies were RCTs (12,672 participants) and nine were CCTs (2259 participants). Overall, the risk of bias was mostly unclear or high. We used GRADE to assess the certainty of the evidence and this was downgraded due to the risk of bias, imprecision or indirectness. The addition of pharmacological prophylaxis to IPC compared with IPC alone reduced the incidence of symptomatic PE from 1.34% (34/2530) in the IPC group to 0.65% (19/2932) in the combined group (OR 0.51, 95% CI 0.29 to 0.91; 19 studies, 5462 participants, low-certainty evidence). The incidence of DVT was 3.81% in the IPC group and 2.03% in the combined group showing a reduced incidence of DVT in favour of the combined group (OR 0.51, 95% CI 0.36 to 0.72; 18 studies, 5394 participants, low-certainty evidence). The addition of pharmacological prophylaxis to IPC, however, increased the risk of any bleeding compared to IPC alone: 0.95% (22/2304) in the IPC group and 5.88% (137/2330) in the combined group (OR 6.02, 95% CI 3.88 to 9.35; 13 studies, 4634 participants, very low-certainty evidence). Major bleeding followed a similar pattern: 0.34% (7/2054) in the IPC group compared to 2.21% (46/2079) in the combined group (OR 5.77, 95% CI 2.81 to 11.83; 12 studies, 4133 participants, very low-certainty evidence). Tests for subgroup differences between orthopaedic and non-orthopaedic surgery participants were not possible for PE incidence as no PE events were reported in the orthopaedic subgroup. No difference was detected between orthopaedic and non-orthopaedic surgery participants for DVT incidence (test for subgroup difference P = 0.19).  The use of combined IPC and pharmacological prophylaxis modalities compared with pharmacological prophylaxis alone reduced the incidence of PE from 1.84% (61/3318) in the pharmacological prophylaxis group to 0.91% (31/3419) in the combined group (OR 0.46, 95% CI 0.30 to 0.71; 15 studies, 6737 participants, low-certainty evidence). The incidence of DVT was 9.28% (288/3105) in the pharmacological prophylaxis group and 5.48% (167/3046) in the combined group (OR 0.38, 95% CI 0.21 to 0.70; 17 studies; 6151 participants, high-certainty evidence). Increased bleeding side effects were not observed for IPC when it was added to anticoagulation (any bleeding: OR 0.87, 95% CI 0.56 to 1.35, 6 studies, 1314 participants, very low-certainty evidence; major bleeding: OR 1.21, 95% CI 0.35 to 4.18, 5 studies, 908 participants, very low-certainty evidence). No difference was detected between the orthopaedic and non-orthopaedic surgery participants for PE incidence (test for subgroup difference P = 0.82) or for DVT incidence (test for subgroup difference P = 0.69).

AUTHORS' CONCLUSIONS

Evidence suggests that combining IPC with pharmacological prophylaxis, compared to IPC alone reduces the incidence of both PE and DVT (low-certainty evidence). Combining IPC with pharmacological prophylaxis, compared to pharmacological prophylaxis alone, reduces the incidence of both PE (low-certainty evidence) and DVT (high-certainty evidence). We downgraded due to risk of bias in study methodology and imprecision. Very low-certainty evidence suggests that the addition of pharmacological prophylaxis to IPC increased the risk of bleeding compared to IPC alone, a side effect not observed when IPC is added to pharmacological prophylaxis (very low-certainty evidence), as expected for a physical method of thromboprophylaxis. The certainty of the evidence for bleeding was downgraded to very low due to risk of bias in study methodology, imprecision and indirectness. The results of this update agree with current guideline recommendations, which support the use of combined modalities in hospitalised people (limited to those with trauma or undergoing surgery) at risk of developing VTE. More studies on the role of combined modalities in VTE prevention are needed to provide evidence for specific patient groups and to increase our certainty in the evidence.

Passive ankle motion and calf massage without anticoagulation therapy after total hip arthroplasty: A retrospective study

BACKGROUND

It has been previously reported that manual calf massage and passive ankle motion after total hip arthroplasty could reduce the incidence of venous thromboembolism. However, a combination of chemical and mechanical prophylaxes was employed. In this study, we aimed to examine the effect of mechanical prevention without pharmacological antithrombotic intervention.

METHODS

Of the 313 patients who underwent unilateral primary total hip arthroplasty and received passive ankle motion and calf massage postoperatively at our hospital between January 2015 and December 2019, 261 (58 men, 203 women; mean age 62.1 years) were included in this retrospective study. Pharmacological anticoagulation therapy was administered in 176 patients (combination group); 137 patients only underwent calf massage and passive ankle motion without anticoagulation therapy (single group). The study outcomes were operation time, the incidence of deep vein thrombosis, pulmonary thromboembolism, intraoperative bleeding, estimated actual blood loss, blood transfusion, and major bleeding.

RESULTS

No significant differences were found in sex, age, side, platelet counts, activated partial thromboplastin time, prothrombin time, prothrombin time - International Normalized Ratio, intraoperative blood loss, estimated blood loss, and operation time. Moreover, the incidence of deep vein thrombosis, pulmonary thromboembolism, and intraoperative bleeding was not significantly different between the groups (deep vein thrombosis 4.0% vs. 6.3%, p = 0.244; pulmonary thromboembolism 0.7% vs. 0%, p = 0.548; and intraoperative bleeding 394 ± 173.6 ml vs. 365.4 ± 168.5 ml, p = 0.550). However, estimated actual blood loss and postoperative bleeding differed between the groups (eABL 996.6 ± 348.3 ml vs. 858.5 ± 269.6 ml, p = 0.003; postoperative bleeding 601.8 ± 330.0 ml vs. 492.1 ± 277.1 ml, p = 0.016), and both increased in the combination group. No major bleeding was noted in the two groups.

CONCLUSION

Postoperative anticoagulant therapy does not have to be routinely used if mechanical prophylaxis is performed in patients without deep vein thrombosis before total hip arthroplasty.

Effectiveness and Tolerability of Fondaparinux vs Enoxaparin in a Population of Indian Patients with Symptomatic Deep Vein Thrombosis: A Retrospective Real-World Study

BACKGROUND

Fondaparinux is the first approved anticoagulant drug among factor Xa inhibitors, with proven effectiveness and safety in preventing deep vein thrombosis. However, limited data are available supporting the benefit-risk profile of fondaparinux vs enoxaparin in a real-world group of Indian patients with deep vein thrombosis.

OBJECTIVE

To compare the effectiveness and tolerability of fondaparinux vs enoxaparin in patients with symptomatic deep vein thrombosis in a long-term real-world setting.

METHODS

Data from the electronic medical records of adult patients diagnosed with deep vein thrombosis prescribed fondaparinux (n = 503) or enoxaparin (n = 508) as monotherapy were analyzed. Effectiveness was analyzed in terms of recurrence, duration, and type of deep vein thrombosis event, and tolerability as bleeding events at initial hospitalization and follow-up visits up to 3 months duration. Appropriate statistical methods were used to determine the significance (p < 0.05) between the two groups.

RESULTS

The deep vein thrombosis recurrence in the fondaparinux group was non-inferior (2.78%) when compared with enoxaparin (3.76%), with a mean duration of 47 and 48 days, respectively. The number of events and mean duration of events (in days) were not significant (p > 0.05). Major bleeding events were higher in the enoxaparin group at 3.17% than the fondaparinux group at 2.19%, and the difference was not statistically significant (p > 0.05).

CONCLUSIONS

The weight-based, once-daily subcutaneous fondaparinux dose showed non-inferior effectiveness and a comparable tolerability profile when compared with the twice-daily enoxaparin dose for the management of symptomatic deep vein thrombosis.

Incidences of deep vein thrombosis and major bleeding under the administration of fondaparinux for thromboprophylaxis after periacetabular osteotomy: a retrospective observational study

Periacetabular osteotomy (PAO) is an effective joint-preserving procedure for patients with developmental dysplasia of the hip. Although deep vein thrombosis (DVT) is considered a serious complication of orthopaedic surgery, there is no consensus regarding a thromboprophylaxis strategy after PAO. We have routinely administered fondaparinux for DVT prophylaxis in adult patients undergoing PAO. The aim of this study was to investigate the incidences of DVT and major bleeding under the administration of fondaparinux for thromboprophylaxis after PAO. A total of 95 patients (100 hips) who underwent PAO with post-operative administration of fondaparinux for thromboprophylaxis were retrospectively enrolled. The incidences of DVT on ultrasound, major bleeding, and administration cessation were evaluated. Asymptomatic DVT occurred in one patient, major bleeding occurred in 14 hips and the administration of fondaparinux was stopped in 17 hips. Given the observed incidence of major bleeding, safer DVT prophylaxis modalities should be considered during PAO.

Benefits of early ambulation within 24 h after total knee arthroplasty: a multicenter retrospective cohort study in China

BACKGROUND

Postoperative care has been evolving since the concept of enhanced recovery after surgery (ERAS) was introduced in China. This study aimed to evaluate the effects of early ambulation within 24 h after unilateral total knee arthroplasty (TKA) on postoperative rehabilitation and costs in a Chinese population.

METHODS

This cohort study of patients with knee osteoarthritis who had undergone TKA at 24 large teaching hospitals between January 2014 and November 2016 involved 2687 patients who began ambulating within 24 h (Group A) and 3761 who began ambulating later than 24 h (Group B). The outcome measurements, such as length of stay (LOS), total hospitalization costs, dynamic pain level, knee flexion range of motion (ROM), results of the 12-Item Short Form Survey (SF-12), incidence of thromboembolic events and other complications, were recorded and compared.

RESULTS

The early ambulation group (Group A) had a shorter LOS and lower hospitalization costs and pain levels than the late ambulation group (Group B). There was a favorable effect in enhancing ROM for patients in Group A compared with patients in Group B. In Group A, patients had significantly higher postoperative SF-12 scores than those in Group B. The incidence of deep venous thrombosis (DVT) and pulmonary infection was significantly lower in Group A than in Group B. The incidence of pulmonary embolism (PE) and other complications did not differ between the two groups.

CONCLUSION

Early ambulation within 24 h after TKA was associated with reduced LOS, improved knee function, lower hospitalization costs and lower incidence of DVT and pulmonary infection in the Chinese population.

Is there a role of tranexamic acid in rheumatoid arthritis with total knee arthroplasty? Findings from a multicenter prospective cohort study in China

BACKGROUND

Tranexamic acid (TXA) has proven to be effective in reducing the blood loss associated with total knee arthroplasty (TKA) in patients with osteoarthritis. However, there still exists a paucity of evidence regarding the effectiveness of intravenous TXA in patients with rheumatoid arthritis. The aim of this study was to explore the efficacy and safety of intravenous TXA on blood loss after TKA in Chinese patients with rheumatoid arthritis.

MATERIALS AND METHODS

A total of 405 patients with rheumatoid arthritis who had undergone TKA were categorized into two groups based on the protocol of TXA use. TXA group (n = 248): patients received 15 mg/kg TXA prior to operation. Control group (n = 157): patients received no TXA. The outcome measurements such as, total blood loss (TBL), intraoperative blood loss (IBL), hidden blood loss (HBL), transfusion, drainage, the timing of first ambulation, the length of stay (LOS), total hospitalization costs, the results of 12-Item Short Form Survey (SF-12), the incidence of thromboembolic events and other complications were recorded and compared.

RESULTS

The mean TBL, IBL, HBL, volume of transfusion and drainage were significantly lower in TXA group than in Control group. The rate of transfusion was significantly lower in TXA group than in Control group. There was a favorable effect in early ambulation for patients in TXA group, compared with patients in Control group. In addition, TXA group had shorter LOS, lower hospitalization costs and higher postoperative SF-12 score than Control group. The incidence of deep venous thrombosis and other complications did not differ between the two groups.

CONCLUSION

TXA can effectively diminish blood loss, reduce transfusion, shorten LOS and decrease hospitalization costs after TKA in Chinese patients with rheumatoid arthritis, without increasing the risk of complications.

Ethnoracial variations in venous thrombosis: Implications for management, and a call to action

Despite decades of improvement in its diagnosis and management, venous thromboembolism (VTE) remains a significant cause of cardiovascular morbidity and mortality. Clinically relevant differences exist in the risk of symptomatic VTE among ethnoracial groups. Underlying these differences in rates of VTE are patterns of known genetic thrombophilias, which may also influence the risks of major bleeding related to vitamin K antagonists or direct oral anticoagulants. In addition, social factors, differential access to care, and disease awareness differ between ethnoracial groups, which contributes to disparities in VTE outcomes that include higher fatal events. The vast majority of participants included in clinical trials for the prevention and treatment of VTE have been White Caucasian, which limits our understanding of the differential impact of these agents in non-White ethnoracial groups. Increasing the participation in clinical trials of diverse ethnoracial groups should be a priority, especially those groups who are disproportionately affected by the burden of VTE, or possible bleeding complications when exposed to anticoagulants. Advocacy by patients, researchers, and regulatory bodies is crucial to ensure adequate enrolment of diverse ethnoracial groups in order to best inform clinical decisions to optimize VTE prevention and treatment for non-White populations.

Fondaparinux Sodium Compared With Low-Molecular-Weight Heparins for Perioperative Surgical Thromboprophylaxis: A Systematic Review and Meta-analysis

Background

Fondaparinux sodium has been compared with low‐molecular‐weight heparins (LMWH) in randomized controlled trials for perioperative surgical thromboprophylaxis. However, the results from these studies are inconsistent in terms of efficacy and safety to reach a clinical decision. The objective of this study was to systematically review the randomized controlled trials comparing the efficacy and safety of fondaparinux and LMWH for perioperative surgical thromboprophylaxis.

Methods and Results

Systematic search in various databases was done to identify randomized controlled trials comparing fondaparinux and LMWH published during the years 2000 to 2017. Outcomes of interest in this study included venous thromboembolism up to day 15, all‐cause mortality up to day 90, major bleeding, and minor bleeding during the treatment period. Analyses were performed with the relative odds based on a random‐effects model using Mantel‐Haenszel statistics. Results were presented as odds ratios with their 95% CIs. The assessment of study quality was performed as per Cochrane collaboration. After screening 10 644 articles, 12 randomized controlled trials including 14 906 patients were included in the final analyses. Pooled analyses showed the odds of venous thromboembolism in the fondaparinux group were 0.49 times the odds in LMWH group (OR=0.49 [0.38–0.64]). However, the odds of major bleeding in the fondaparinux group were 1.48 times the odds in the LMWH group (OR=1.48 [1.15–1.90]).

Conclusions

Fondaparinux was associated with a superior efficacy in terms of reduction of venous thromboembolism in this meta‐analysis. However, it was also associated with increased odds of major bleeding.

Portable compression devices in total joint arthroplasty: poor outpatient compliance

Background

Aspirin and mechanical compression devices are approved means of venous thromboembolism (VTE) prophylaxis after total joint arthroplasty. Prior studies of mechanical compression pumps after joint arthroplasty have been limited to the inpatient setting. The purpose of this study was to evaluate outpatient compliance and utilization factors in a rural population after elective hip or knee arthroplasty.

Methods

Utilization for portable pneumatic compression pumps after joint arthroplasty was prospectively recorded (hours). Compliance was defined as the recommended 20 hours per day. A questionnaire 2 weeks postoperatively assessed factors that may contribute to noncompliance. Patients were followed up for 90 days postoperatively to record VTE events.

Results

Data were collected for 115 joint arthroplasty patients (50 hips, 65 knees). Postdischarge day one had the highest average usage at 13.2 hours/day (66.0%, range 0%-100%), but this number fell to 4.8 hours/day (24.0, range 0%-100%) by day 14. Patient compliance (>20 hours use/day) was highest on postdischarge day one at 40 patients (34.7%). By postdischarge day 14, patient compliance fell to 17 patients (14.8%). Difficulty using the pumps (P = .027) and pump-associated heat (P = .009) were significantly associated with patient compliance. A deep vein thrombosis and nonfatal pulmonary embolism were recorded in 2 separate patients.

Conclusions

This study demonstrated poor outpatient compliance with portable pneumatic compression devices. Poor compliance was related to pump heat and difficulty with pump use. Even with poor compliance, a low incidence of VTE events was observed.

Asymptomatic Deep Venous Thrombosis After Elective Hip Surgery Could Be Allowed to Remain in Place Without Thromboprophylaxis After a Minimum 2-Year Follow-Up

BACKGROUND

It is not clear how to treat asymptomatic deep venous thromboses (DVTs) following elective hip arthroplasty because the natural course of DVTs is unclear. It is therefore valuable to understand the natural course of DVTs and their relation to thromboprophylactic methods.

METHODS

We followed 742 consecutive patients who underwent elective hip arthroplasty followed by mechanical or chemical prophylaxis of a DVT. All patients underwent preoperative and postoperative duplex ultrasonography of both limbs. Patients who developed postoperative DVT in the popliteal or calf vein were followed without thromboprophylaxis. DVT-positive patients were prospectively followed up with duplex ultrasonography at 3, 6, 12, and 24 months postoperatively.

RESULTS

Incidences of preoperative and postoperative DVTs were 3.9% and 33.0%, respectively. Nonfatal pulmonary embolism (PE) occurred in 1 patient after negative echography. All DVTs that developed in the calf vein postoperatively and without anticoagulation remained benign, and 93% of the DVTs ultimately disappeared.

CONCLUSION

These results confirmed that the natural course of asymptomatic distal DVTs is benign, with no risk of leading to PE. Thus, distal DVTs could be allowed to remain untreated without chemical prophylaxis to prevent PE in Asian populations.

American Society of Hematology 2019 guidelines for management of venous thromboembolism: prevention of venous thromboembolism in surgical hospitalized patients

BACKGROUND

Venous thromboembolism (VTE) is a common source of perioperative morbidity and mortality.

OBJECTIVE

These evidence-based guidelines from the American Society of Hematology (ASH) intend to support decision making about preventing VTE in patients undergoing surgery.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline-development process, including performing systematic reviews. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations, which were subject to public comment.

RESULTS

The panel agreed on 30 recommendations, including for major surgery in general (n = 8), orthopedic surgery (n = 7), major general surgery (n = 3), major neurosurgical procedures (n = 2), urological surgery (n = 4), cardiac surgery and major vascular surgery (n = 2), major trauma (n = 2), and major gynecological surgery (n = 2).

CONCLUSIONS

For patients undergoing major surgery in general, the panel made conditional recommendations for mechanical prophylaxis over no prophylaxis, for pneumatic compression prophylaxis over graduated compression stockings, and against inferior vena cava filters. In patients undergoing total hip or total knee arthroplasty, conditional recommendations included using either aspirin or anticoagulants, as well as for a direct oral anticoagulant over low-molecular-weight heparin (LMWH). For major general surgery, the panel suggested pharmacological prophylaxis over no prophylaxis, using LMWH or unfractionated heparin. For major neurosurgery, transurethral resection of the prostate, or radical prostatectomy, the panel suggested against pharmacological prophylaxis. For major trauma surgery or major gynecological surgery, the panel suggested pharmacological prophylaxis over no prophylaxis.

Factor Xa Inhibitors and Direct Thrombin Inhibitors Versus Low-Molecular-Weight Heparin for Thromboprophylaxis After Total Hip or Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this study is to perform a meta-analysis to compare outcomes of venous thromboembolism (VTE) prophylaxis with low-molecular-weight heparin (LMWH) vs other anticoagulants in patients who received total knee (TKA) or total hip arthroplasty (THA).

METHODS

MEDLINE, Cochrane, EMBASE, and Google Scholar databases were searched until June 30, 2017 for eligible randomized controlled studies.

RESULTS

Thirty-two randomized controlled studies were included. LMWH provided better protection against VTE than placebo. In both TKA and THA patients, the rates of VTE were lower with factor Xa inhibitors than LMWH. In THA patients, the rate of deep vein thrombosis (DVT) was lower with factor Xa inhibitors than LMWH. In TKA patients, the rates of VTE and DVT were similar between LMWH and direct thrombin inhibitors. In THA patients, the rate of VTE was lower with direct thrombin inhibitors than with LMWH, while the DVT rates were similar. The pulmonary embolism rates were similar between all 3 classes of drugs in TKA and THR patients, as were the major bleeding rates. Nonmajor and minor bleeding rates were also similar between the 3 drug classes.

CONCLUSION

LMWH is associated with a higher rate of VTE than factor Xa inhibitors in TKA and THA patients. Direct thrombin inhibitors are associated with a lower rate of VTE in THA patients, but their effectiveness with respect to DVT and pulmonary embolism prophylaxis is similar to that of LMWH in TKA and THA patients.

Oral anticoagulants for primary prevention, treatment and secondary prevention of venous thromboembolic disease, and for prevention of stroke in atrial fibrillation: systematic review, network meta-analysis and cost-effectiveness analysis

BACKGROUND

Warfarin is effective for stroke prevention in atrial fibrillation (AF), but anticoagulation is underused in clinical care. The risk of venous thromboembolic disease during hospitalisation can be reduced by low-molecular-weight heparin (LMWH): warfarin is the most frequently prescribed anticoagulant for treatment and secondary prevention of venous thromboembolism (VTE). Warfarin-related bleeding is a major reason for hospitalisation for adverse drug effects. Warfarin is cheap but therapeutic monitoring increases treatment costs. Novel oral anticoagulants (NOACs) have more rapid onset and offset of action than warfarin, and more predictable dosing requirements.

OBJECTIVE

To determine the best oral anticoagulant/s for prevention of stroke in AF and for primary prevention, treatment and secondary prevention of VTE.

DESIGN

Four systematic reviews, network meta-analyses (NMAs) and cost-effectiveness analyses (CEAs) of randomised controlled trials.

SETTING

Hospital (VTE primary prevention and acute treatment) and primary care/anticoagulation clinics (AF and VTE secondary prevention).

PARTICIPANTS

Patients eligible for anticoagulation with warfarin (stroke prevention in AF, acute treatment or secondary prevention of VTE) or LMWH (primary prevention of VTE).

INTERVENTIONS

NOACs, warfarin and LMWH, together with other interventions (antiplatelet therapy, placebo) evaluated in the evidence network.

MAIN OUTCOME MEASURES

Efficacy Stroke, symptomatic VTE, symptomatic deep-vein thrombosis and symptomatic pulmonary embolism. Safety Major bleeding, clinically relevant bleeding and intracranial haemorrhage. We also considered myocardial infarction and all-cause mortality and evaluated cost-effectiveness.

DATA SOURCES

MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library, reference lists of published NMAs and trial registries. We searched MEDLINE and PREMEDLINE In-Process & Other Non-Indexed Citations, EMBASE and The Cochrane Library. The stroke prevention in AF review search was run on the 12 March 2014 and updated on 15 September 2014, and covered the period 2010 to September 2014. The search for the three reviews in VTE was run on the 19 March 2014, updated on 15 September 2014, and covered the period 2008 to September 2014.

REVIEW METHODS

Two reviewers screened search results, extracted and checked data, and assessed risk of bias. For each outcome we conducted standard meta-analysis and NMA. We evaluated cost-effectiveness using discrete-time Markov models.

RESULTS

Apixaban (Eliquis^®, Bristol-Myers Squibb, USA; Pfizer, USA) [5 mg bd (twice daily)] was ranked as among the best interventions for stroke prevention in AF, and had the highest expected net benefit. Edoxaban (Lixiana^®, Daiichi Sankyo, Japan) [60 mg od (once daily)] was ranked second for major bleeding and all-cause mortality. Neither the clinical effectiveness analysis nor the CEA provided strong evidence that NOACs should replace postoperative LMWH in primary prevention of VTE. For acute treatment and secondary prevention of VTE, we found little evidence that NOACs offer an efficacy advantage over warfarin, but the risk of bleeding complications was lower for some NOACs than for warfarin. For a willingness-to-pay threshold of > £5000, apixaban (5 mg bd) had the highest expected net benefit for acute treatment of VTE. Aspirin or no pharmacotherapy were likely to be the most cost-effective interventions for secondary prevention of VTE: our results suggest that it is not cost-effective to prescribe NOACs or warfarin for this indication.

CONCLUSIONS

NOACs have advantages over warfarin in patients with AF, but we found no strong evidence that they should replace warfarin or LMWH in primary prevention, treatment or secondary prevention of VTE.

LIMITATIONS

These relate mainly to shortfalls in the primary data: in particular, there were no head-to-head comparisons between different NOAC drugs.

FUTURE WORK

Calculating the expected value of sample information to clarify whether or not it would be justifiable to fund one or more head-to-head trials.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013005324, CRD42013005331 and CRD42013005330.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Manual calf massage and passive ankle motion reduce the incidence of deep vein thromboembolism after total hip arthroplasty

BACKGROUND

Venous thromboembolism is one of the general complications following total hip arthroplasty, wherein various preventive treatments have been recommended. Several studies reported that venous thromboembolism incidence after total hip arthroplasty was similar in patients who were administered prophylaxis with a conventional mechanical procedure alone, and those who were administered pharmacological anticoagulation therapy. Therefore, the optimum methods of prophylaxis are still controversial. The purpose of this study was to investigate whether manual calf massage and passive ankle motion could lower the risk for venous thromboembolism after total hip arthroplasty.

METHODS

We retrospectively reviewed the data of 126 consecutive patients undergoing elective primary unilateral total hip arthroplasty wherein manual calf massage and passive ankle motion were performed after the surgery at our hospitals between January and October 2014. The 138 patients of the control group underwent total hip arthroplasty using the same surgical approach and pre- and postoperative protocols without this mechanical prophylaxis between January and December 2013. This mechanical prophylaxis was performed simultaneously 30 times during approximately 10 s; these procedures were repeated thrice immediately after total hip arthroplasty. Duplex ultrasonography was performed to observe the veins of both legs in all the patients on postoperative day 7.

RESULTS

The incidence of deep vein thrombosis was 6.52% and 0.79% in the control and manual calf massage and passive ankle motion groups, respectively. The odds ratio for the manual calf massage and passive ankle motion groups was 8.72. Performing this mechanical prophylaxis reduced the incidence of venous thromboembolism after total hip arthroplasty. This mechanical prophylaxis is not only simple and easy, but is also safe and inexpensive.

CONCLUSIONS

We therefore recommend that manual calf massage and passive ankle motion be performed in patients who will undergo total hip arthroplasty, if deep vein thrombosis does not exist before the surgery.

Intermittent Pneumatic Compression for the Prevention of Venous Thromboembolism after Total Hip Arthroplasty

BACKGROUND

Venous thromboembolism (VTE) is a relatively common and potentially life threatening complication after major hip surgery. There are two main types of prophylaxis: chemical and mechanical. Chemical prophylaxis is very effective but causes bleeding complications in surgical wounds and remote organs. On the other hand, mechanical methods are free of hemorrhagic complications but are less effective. We hypothesized that mechanical prophylaxis is effective enough for Asians in whom VTE occurs less frequently. This study evaluated the effect of intermittent pneumatic compression (IPC) in the prevention of VTE after major hip surgery.

METHODS

Incidences of symptomatic VTE after primary total hip arthroplasty with and without application of IPC were compared. A total of 379 patients were included in the final analysis. The IPC group included 233 patients (106 men and 127 women) with a mean age of 54 years. The control group included 146 patients (80 men and 66 women) with a mean age of 53 years. All patients took low-dose aspirin for 6 weeks after surgery. IPC was applied to both legs just after surgery and maintained all day until discharge. When a symptom or a sign suspicious of VTE, such as swelling or redness of the foot and ankle, Homans' sign, and dyspnea was detected, computed tomography (CT) angiogram or duplex ultrasonogram was performed.

RESULTS

Until 3 months after surgery, symptomatic VTE occurred in three patients in the IPC group and in 6 patients in the control group. The incidence of VTE was much lower in the IPC group (1.3%) than in the control group (4.1%), but the difference was not statistically significant. Complications associated with the application of IPC were not detected in any patient. Patients affected by VTE were older and hospitalized longer than the unaffected patients.

CONCLUSIONS

The results of this study suggest that IPC might be an effective and safe method for the prevention of postoperative VTE.

Impact of Active Ankle Movement Frequency on Velocity of Lower Limb Venous Flow following Total Hip Arthroplasty

Background. Although active ankle movement plays a predominant role in mechanical thromboprophylaxis following total hip arthroplasty (THA), the most effective frequency of movement remains unclear. Materials and Methods. In 29 consecutive patients undergoing THA, the velocity of blood flow in the profunda femoris was measured after various frequencies of ankle movement two days after THA using a pulse wave Doppler ultrasound system. To test the interobserver reliabilities for the velocity measured with Doppler ultrasound system, the intraclass correlation coefficient was calculated based on the measurement in 10 limbs of healthy volunteers. Results. At 0, 1, and 2 minutes after ankle movement, the velocity after movement at 60 contractions per minute was significantly faster than that after movement at 40 or 80 contractions per minute (p = 0.0007, repeated-measures analysis of variance). The intraclass correlation coefficient score in two investigators was 0.849 (95% confidence interval, 0.428 to 0.962). Conclusions. Active ankle movement at 60 contractions per minute is recommended in patients receiving THA to obtain optimal venous blood flow.

Pentasaccharides for the prevention of venous thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is a common condition with potentially serious and life-threatening consequences. The standard method of thromboprophylaxis uses an anticoagulant such as low molecular weight heparin (LMWH) or warfarin. In recent years, another type of anticoagulant, pentasaccharide, an indirect factor Xa inhibitor, has shown good anticoagulative effect in clinical trials. Three types of pentasaccharides are available: short-acting fondaparinux, long-acting idraparinux and idrabiotaparinux. Pentasaccharides cause little heparin-induced thrombocytopenia and are better tolerated than unfractionated heparin, LMWH and warfarin. However, no consensus has been reached on whether pentasaccharides are superior or inferior to other anticoagulative methods.

OBJECTIVES

To assess effects of pentasaccharides versus other methods of thromboembolic prevention (thromboprophylaxis) in people who require anticoagulant treatment to prevent venous thromboembolism.

SEARCH METHODS

The Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (last searched March 2016) and the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2). The CIS searched trial databases for details of ongoing and unpublished studies. Review authors searched LILACS (Latin American and Caribbean Health Sciences) and the reference lists of relevant studies and reviews identified by electronic searches.

SELECTION CRITERIA

We included randomised controlled trials on any type of pentasaccharide versus other anticoagulation methods (pharmaceutical or mechanical) for VTE prevention.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, assessed methodological quality and extracted data in predesigned tables.

MAIN RESULTS

We included in this review 25 studies with a total of 21,004 participants. All investigated fondaparinux for VTE prevention; none investigated idraparinux or idrabiotaparinux. Studies included participants undergoing abdominal surgery, thoracic surgery, bariatric surgery or coronary bypass surgery; acutely ill hospitalised medical patients; people requiring rigid or semirigid immobilisation; and those with superficial venous thrombosis. Most studies focused on orthopaedic patients. We lowered the quality of the evidence because of heterogeneity between studies and a small number of events causing imprecision.When comparing fondaparinux with placebo, we found less total VTE (risk ratio (RR) 0.24, 95% confidence interval (CI) 0.15 to 0.38; 5717 participants; 8 studies; I2 = 64%; P < 0.00001), less symptomatic VTE (RR 0.15, 95% CI 0.06 to 0.36; 6503 participants; 8 studies; I2 = 0%; P < 0.0001), less total DVT (RR 0.25, 95% CI 0.15 to 0.40; 5715 participants; 8 studies; I2 = 67%; P < 0.00001), less proximal DVT (RR 0.12, 95% CI 0.04 to 0.39; 2746 participants; 7 studies; I2 = 64%; P = 0.0004) and less total pulmonary embolism (PE) (RR 0.16, 95% CI 0.04 to 0.62; 6412 participants; 8 studies; I2 = 0%; P = 0.008) in the fondaparinux group. The quality of the evidence was moderate for total VTE, total DVT and proximal DVT, and high for symptomatic VTE and total PE.When fondaparinux was compared with LMWH, analyses indicated that fondaparinux reduced total VTE and DVT (RR 0.55, 95% CI 0.42 to 0.73; 9339 participants; 11 studies; I2 = 64%; P < 0.0001; and RR 0.54, 95% CI 0.40 to 0.71; 9356 participants; 10 studies; I2 = 67%; P < 0.0001, respectively), and showed a trend toward reduced proximal DVT (RR 0.58, 95% CI 0.33 to 1.02; 8361 participants; 9 studies; I2 = 53%; P = 0.06). Symptomatic VTE (RR 1.03, 95% CI 0.65 to 1.63; 12240 participants; 9 studies; I2 = 35%; P = 0.90) and total PE (RR 1.24, 95% CI 0.65 to 2.34; 12350 participants; 10 studies; I2 = 0%; P = 0.51) indicated no difference between fondaparinux and LMWH. The quality of the evidence was moderate for total VTE, symptomatic VTE, total DVT and total PE, and low for proximal DVT.We showed that fondaparinux increased major bleeding compared with both placebo and LWMH (RR 2.56, 95% CI 1.48 to 4.44; 6659 participants; 8 studies; I2 = 0%; P = 0.0008; moderate-quality evidence; and RR 1.38, 95% CI 1.09 to 1.75; 12,501 participants; 11 studies; I2 = 24%; P = 0.008; high-quality evidence, respectively). All-cause mortality was not different between fondaparinux and placebo or LMWH (RR 0.76, 95% CI 0.48 to 1.22; 6674 participants; 8 studies; I2 = 14%; P = 0.26; moderate-quality evidence; and RR 0.88, 95% CI 0.63 to 1.22; 12,400 participants; 11 studies; I2 = 0%; P = 0.44; moderate-quality evidence, respectively).One study compared fondaparinux with variable and fixed (1 mg per day) doses of warfarin after elective hip or knee replacement surgery and showed no difference in primary and secondary outcomes between fondaparinux and both variable and fixed doses of warfarin. The quality of the evidence was very low. One small study compared fondaparinux with edoxaban in patients with severe renal impairment undergoing lower-limb orthopaedic surgery and reported no thromboembolic events, major bleeding events or deaths in either group. The quality of the evidence was very low. One small study compared fondaparinux with mechanical thromboprophylaxis. Results showed no difference in total VTE and total DVT between fondaparinux and mechanical thromboprophylaxis. This study reported no cases pertaining to the other outcomes of this review. The quality of the evidence was low.There were insufficient studies to permit meaningful conclusions for subgroups of clinical conditions other than orthopaedic surgery.

AUTHORS' CONCLUSIONS

Moderate to high quality evidence shows that fondaparinux is effective for short-term prevention of VTE when compared with placebo. It can reduce total VTE, DVT, total PE and symptomatic VTE, and does not demonstrate a reduction in deaths compared with placebo. Low to moderate quality evidence shows that fondaparinux is more effective for short-term VTE prevention when compared with LMWH. It can reduce total VTE and total DVT and does not demonstrate a reduction in deaths when compared with LMWH. However, at the same time, moderate to high quality evidence shows that fondaparinux increases major bleeding when compared with placebo and LMWH. Therefore, when fondaparinux is chosen for the prevention of VTE, attention should be paid to the person's bleeding and thrombosis risks. Most data were derived from patients undergoing orthopaedic surgery. Therefore, the conclusion predominantly pertains to these patients. Data on fondaparinux for other clinical conditions are sparse.

The incidence of deep vein thrombosis (DVT) during hip arthroscopic surgery

INTRODUCTION

The use of hip arthroscopy has been widely increasing. Although deep vein thrombosis (DVT) is thought to be a serious complication of orthopaedic surgery, there were few reports discussing DVT related to hip arthroscopic surgery. This study aimed to investigate the incidence and risk factors of DVT related to hip arthroscopic surgery.

MATERIALS AND METHODS

This retrospective study included 72 patients. Clinical diagnosis of DVT was confirmed through ultrasonography performed preoperatively and 3 days postoperatively. Additionally, D-dimer levels were measured preoperatively and on postoperative days 1, 3, and 7. Age, body mass index, operation time, procedure type, and D-dimer levels were statistically compared between the two groups (identified DVT vs. no identified DVT).

RESULTS

Five patients (6.94 %) were diagnosed with DVT clinically, although all cases were asymptomatic. The mean age of the patients with identified DVT was 62.0 ± 6.1 years; significantly higher than the mean age of the patients without DVT (45.1 ± 1.7 years; P = 0.0188).

CONCLUSION

The incidence of DVT during hip arthroscopy, investigated by ultrasound, was 6.94 %. From our results, we recommend screening for and treatment of asymptomatic DVT, especially in older patients, during hip arthroscopic surgery.

Combined intermittent pneumatic leg compression and pharmacological prophylaxis for prevention of venous thromboembolism

BACKGROUND

It is generally assumed by practitioners and guideline authors that combined modalities (methods of treatment) are more effective than single modalities in preventing venous thromboembolism (VTE), defined as deep vein thrombosis (DVT) or pulmonary embolism (PE), or both. This is an update of the review first published in 2008.

OBJECTIVES

The aim of this review was to assess the efficacy of combined intermittent pneumatic leg compression (IPC) and pharmacological prophylaxis versus single modalities in preventing venous thromboembolism.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (May 2016). In addition the CIS searched the Cochrane Register of Studies (CENTRAL (2016, Issue 4)). Clinical trials databases were searched for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomized controlled trials (RCTs) or controlled clinical trials (CCTs) of combined IPC and pharmacological interventions used to prevent VTE.

DATA COLLECTION AND ANALYSIS

We independently selected trials and extracted data. Disagreements were resolved by discussion. We performed fixed-effect model meta-analyses with odds ratios (ORs) and 95% confidence intervals (CIs). We used a random-effects model when there was heterogeneity.

MAIN RESULTS

We included a total of 22 trials (9137 participants) of which 15 were randomized trials (7762 participants). The overall risk of bias was mostly unclear or high due to selection and performance bias. We used GRADE to assess the quality of the evidence and this was downgraded from high to moderate or very low due to the risk of bias, imprecision or indirectness.The rate of PE in the studies comparing IPC alone with combined IPC and pharmacological prophylaxis was low, underpowering the analyses. The incidence of symptomatic PE was 0.79% with IPC, but ranged between 0.1 to 1% with combined IPC and pharmacological prophylaxis (OR 0.49, 95% CI 0.18 to 1.34; 12 studies, 3017 participants, moderate quality evidence). The incidence of DVT was 4.10% in the IPC group and 2.19% in the combined group showing a reduced incidence of DVT in favour of the combined group (OR 0.52, 95% CI 0.33 to 0.82; 11 studies, 2934 participants, moderate quality evidence). The addition of an anticoagulant to IPC, however, increased the risk of any bleeding compared to IPC alone; 0.66% (7/1053) in the IPC group and 4.0% (44/1102) in the combined group (OR 5.04, 95% CI 2.36 to 10.77; 7 studies, 2155 participants, moderate quality evidence). Major bleeding followed a similar pattern; 0.1% (1/1053) in the IPC group to 1.5% (17/1102) in the combined group (OR 6.81, 95% CI 1.99 to 23.28; 7 studies, 2155 participants, moderate quality evidence).We detected no difference between the type of surgery subgroups such as orthopedic and non-orthopedic participants for DVT incidence (P = 0.16). Tests for differences between type of surgery subgroups were not possible for PE incidence.Compared with pharmacological prophylaxis alone, the use of combined IPC and pharmacological prophylaxis modalities reduced the incidence of symptomatic PE from 2.92% to 1.20% (OR 0.39, 95% CI 0.23 to 0.64; 10 studies, 3544 participants, moderate quality evidence). The incidence of DVT was 6.2% in the pharmacological prophylaxis group and 2.9% in the combined group showing no difference between the combined and pharmacological prophylaxis groups (OR 0.42, 95% CI 0.18 to 1.03; 11 studies, 2866 participants, moderate quality evidence). Increased bleeding side effects were not observed for IPC when it was added to anticoagulation (bleeding: OR 0.80, 95% CI 0.30 to 2.14, very low quality evidence; major bleeding: OR 1.21, 95% CI 0.35 to 4.18, very low quality evidence, 3 studies, 244 participants).No difference was detected between the type of surgery subgroups for PE incidence (P = 0.68) or for DVT incidence (P = 0.10).

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests that combining IPC and pharmacological prophylaxis, compared with IPC or pharmacological prophylaxis alone, decreases the incidence of DVT when compared to compression, and incidence of PE when compared to anticoagulation. Moderate quality evidence suggests that there is no difference between combined and single modalities in the incidence of PE when compared with compression alone and DVT when compared with anticoagulation alone. The quality of evidence for PE or DVT was downgraded to moderate due to imprecision or risk of bias in study methodology, highlighting the need for further research. Moderate quality evidence suggests the addition of pharmacological prophylaxis to IPC, increased the risk of bleeding compared to IPC alone, a side effect not observed for IPC when added to pharmacological prophylaxis (very low quality evidence), as expected for a physical method of thromboprophylaxis. The quality of evidence for bleeding was downgraded to moderate due to indirectness or very low due to risk of bias in study methodology, indirectness and imprecision highlighting the need for further research. Nevertheless, the results of the current review agree with current guideline recommendations, which support the use of combined modalities in hospitalised patients (limited to those with trauma or undergoing surgery) at risk of developing VTE. More studies on the role of combined modalities in VTE prevention are needed.

Fondaparinux vs. enoxaparin for the prevention of venous thromboembolism after total hip replacement: A meta-analysis

The aim of the study was to compare the efficacy and safety profiles of fondaparinux and enoxaparin in preventing the venous thromboembolism (VTE) after total hip replacement. A systematic literature search in the PubMed, EMBASE and Cochrane library databases was performed to identify relevant articles published in English since inception up to November 16, 2014. The efficacy outcomes were all VTE, total deep vein thrombosis (DVT) and symptomatic VTE, while the safety outcome was major bleeding. Four eligible studies were included in the meta-analysis. The incidences of total VTEs and DVTs were significantly decreased with the use of fondaparinux when compared to enoxaparin [total VTE: risk ratio (RR)=0.59, 95% confidence interval (CI): 0.46–0.74, P<0.01; total DVT: RR=0.58, 95% CI: 0.46–0.74, P<0.01]. Significantly fewer symptomatic VTEs and major bleeding cases were observed for the enoxaparin group (symptomatic VTE: RR=2.62, 95% CI: 1.07–6.45, P=0.04; major bleeding: RR=1.75, 95% CI: 1.20–2.53, P<0.01). In conclusion, the pooled analysis revealed that, compared to enoxaparin, fondaparinux was significantly more effective in preventing VTE after total hip replacements in terms of total VTEs and DVTs, although this was accompanied with an increased risk of major bleeding. However, the pooled analysis of two small sample trials from Japan failed to demonstrate any significant advantage for fondaparinux compared to enoxaparin.

Venous thromboembolism after lower limb arthroplasty: is chemical prophylaxis still needed?

BACKGROUND

Venous thromboembolism (VTE) is a significant complication of lower limb arthroplasty. The National Institute for Health and Care Excellence recommends routine use of chemical and mechanical prophylaxis to prevent VTE. Our high-volume, elective, arthroplasty unit adopted this guidance in 2008.

PURPOSE

We examined our incidence of VTE before and after introduction of chemical thromboprophylaxis to determine whether the incidence of VTE reduced.

METHODS

We retrospectively gathered data on 2 cohorts of patients-from January 2004 to August 2007 (Group 1) and January 2010 to December 2012 (Group 2). Patients in Group 1 received mechanical prophylaxis only (unless particularly high risk for VTE), and patients in Group 2 received mechanical and chemical prophylaxis. We recorded VTE occurring within 6 months of surgery. Patients in Group 1 receiving chemical prophylaxis were excluded.

RESULTS

Group 1 had 2320 cases of primary and revision lower limb arthroplasty, and Group 2 had 1430 cases. VTE occurred in 37 cases in Group 1 (1.6 %), and in 17 cases in Group 2 (1.2 %). This difference was not statistically significant (p = 0.26). In Group 1, 1 patient died within 6 months due to pulmonary embolism (0.04 %); there were no VTE-related deaths in Group 2 (0 %). This was also not statistically significant (p = 0.06).

CONCLUSIONS

Although our VTE rate reduced by 0.4 % and our VTE-related mortality reduced by 0.04 % after introduction of chemical thromboprophylaxis, these differences were not statistically significant. Chemical thromboprophylaxis may not be required in all patients undergoing arthroplasty providing appropriate mechanical prophylaxis is used.

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.

Venous Thromboembolism Following Hip and Knee Replacement Arthroplasty in Korea: A Nationwide Study Based on Claims Registry

The aim of this study was to examine the incidence and trends of clinically relevant venous thromboembolism (VTE) including deep vein thrombosis (DVT) and pulmonary embolism (PE) after hip and knee replacement arthroplasty (HKRA) in Korea. Between January 1 and December 31, 2010, 22,127 hip replacement arthroplasty (HRA) patients and 52,882 knee replacement arthroplasty (KRA) patients were enrolled in the analysis using the administrative claims database of the Health Insurance Review and Assessment Service (HIRA). All available parameters including procedure history and clinically relevant VTE during the 90 days after HKRA were identified based on diagnostic and electronic data interchange (EDI) codes. The overall incidence of VTE, DVT, and PE during the 90 days was 3.9% (n=853), 2.7% (n=597), and 1.5% (n=327) after HRA, while the incidence was 3.8% (n=1,990), 3.2% (n=1,699), and 0.7% (n=355) after KRA. The incidence of VTE after HKRA was significantly higher in patients who had previous VTE history (odds ratio [OR], 10.8 after HRA, OR, 8.5 after KRA), chronic heart failure (2.1, 1.3), arrhythmia (1.8, 1.7), and atrial fibrillation (3.4, 2.1) than in patients who did not. The VTE incidence in patients with chemoprophylaxis was higher than that in patients without chemoprophylaxis. The incidence of VTEs revealed in this retrospective review was not low compared with the results of the studies targeting other Asian or Caucasian populations. It may warrant routine prevention including employment of chemoprophylaxis. However, the limitation of the reviewed data mandates large scale prospective investigation to affirm this observation.

A Current Review of Mechanical Compression and Its Role in Venous Thromboembolic Prophylaxis in Total Knee and Total Hip Arthroplasty

Interest in mechanical compression for venous thromboembolic disease prophylaxis has increased over the last several years because of concerns related to bleeding complications associated with chemoprophylaxis. However, the research evaluating compression is clearly not definitive. Therefore, this review aims to: (1) summarize methods of compression; (2) compare AAOS, ACCP, and SCIP guidelines; and (3) make recommendations regarding usage. Below-the-knee devices have demonstrated the most efficacy with multiple guidelines recommending usage. Efficacy and compliance may be improved with the use of mobile devices.

Prophylactic effect of fondaparinux and enoxaparin for preventing pulmonary embolism after total hip or knee arthroplasty: A retrospective observational study using the Japanese Diagnosis Procedure Combination database

OBJECTIVES

The aim of this study was to estimate the effect of fondaparinux and enoxaparin combined with mechanical prophylaxis (MP) after total hip arthroplasty (THA) and total knee arthroplasty (TKA). We also investigated the occurrence of pulmonary embolism (PE) and its associated risk factors.

METHODS

Data were retrospectively collected on patients who underwent THA or TKA between 2008 and 2010 from the Japanese Diagnosis Procedure Combination database (n = 49,678). We extracted information on sex, age, main diagnosis, types of anesthesia, duration of anesthesia, comorbidities, hospital volume, the use of MP, and the use of anticoagulant drugs.

RESULTS

The overall occurrence of PE was 0.41%. Multivariate logistic regression analysis showed that the occurrence of PE was significantly higher in females (odds ratio, 2.17; p < 0.001, compared with males), TKA (1.47; p = 0.039, compared with THA), and longer-duration anesthesia (2.63; p = 0.008 in the ≥ 240-min. group compared with the ≤ 119-min. group). Compared with the MP-alone group, the occurrence of PE was significantly reduced in the fondaparinux group (0.58; p = 0.025) and the enoxaparin group (0.59; p = 0.046).

CONCLUSIONS

Fondaparinux or enoxaparin combined with MP decreased the occurrence of PE. The risk factors for PE were female patients, TKA, and longer-duration anesthesia (≥ 240 min.).

Meta-analysis of randomized trials comparing combined compression and anticoagulation with either modality alone for prevention of venous thromboembolism after surgery

Background

Although venous thromboembolism (VTE) is an important cause of postoperative morbidity and mortality, there is still no consensus on the optimal strategy for VTE prevention after major surgery. The objective of this review was to determine the benefits and risks of thromboprophylaxis with both compression and anticoagulation, compared with either modality alone.

Methods

A systematic review of MEDLINE, CENTRAL and Embase databases was performed to identify eligible randomized trials. The literature search and data extraction were carried out independently by two reviewers. Outcomes of interest were deep vein thrombosis (DVT), pulmonary embolism, bleeding, limb injury and mortality.

Results

Twenty-five studies were eligible for inclusion. Adding compression to anticoagulation decreased the risk of DVT by 49 per cent (risk ratio (RR) 0·51, 95 per cent confidence interval 0·36 to 0·73). The corresponding funnel plot suggested publication bias and, overall, the evidence for this comparison was judged to be of low quality. Adding anticoagulation to compression decreased the risk of DVT by 44 per cent (RR 0·56, 0·45 to 0·69) while increasing the risk of bleeding (RR 1·74, 1·29 to 2·34). There was no suggestion of publication bias and the evidence for this comparison was judged to be of moderate quality.

Conclusion

Combined compression and anticoagulation is more effective at preventing postoperative DVT than either modality alone. However, adding anticoagulation to compression increases the risk of bleeding, and the evidence that adding compression to anticoagulation reduces VTE risk is of low quality.

The rate of symptomatic venous thromboembolism in patients undergoing elective Ilizarov surgery and the cost of chemical prophylaxis

Recent recommendations by the National Institute for Health and Care Excellence (NICE) suggest that all patients undergoing elective orthopaedic surgery should be assessed for the risk of venous thromboembolism (VTE).

Little is known about the incidence of symptomatic VTE after elective external fixation. We studied a consecutive series of adult patients who had undergone elective Ilizarov surgery without routine pharmacological prophylaxis to establish the incidence of symptomatic VTE.

A review of a prospectively maintained database of consecutive patients who were treated between October 1998 and February 2011 identified 457 frames in 442 adults whose mean age was 42.6 years (16.0 to 84.6). There were 425 lower limb and 32 upper limb frames. The mean duration of treatment was 25.7 weeks (1.6 to 85.3).

According to NICE guidelines all the patients had at least one risk factor for VTE, 246 had two, 172 had three and 31 had four or more.

One patient (0.23%) developed a pulmonary embolus after surgery and was later found to have an inherited thrombophilia. There were 27 deaths, all unrelated to VTE.

The cost of providing VTE prophylaxis according to NICE guidelines in this group of patients would be £89 493.40 (£195.80 per patient) even if the cheapest recommended medication was used.

The rate of symptomatic VTE after Ilizarov surgery was low despite using no pharmacological prophylaxis. This study leads us to question whether NICE guidelines are applicable to these patients.

Cite this article: Bone Joint J 2014;96-B:426–30.

The necessity of pharmacological prophylaxis against venous thromboembolism in major joint arthroplasty

PURPOSE

Venous thromboembolism (VTE) is a recognised post-operative complication of major lower limb joint arthroplasty. Current National Institute for Health and Clinical Excellence (NICE) guidelines suggest the use of both mechanical and pharmacological prophylaxis following hip and knee replacement. Since the introduction of enhanced recovery programmes following hip and knee arthroplasty the requirement for routine pharmacological VTE prophylaxis has been questioned. The purpose of this study was to assess the efficacy of pharmacological prophylaxis against symptomatic VTE in patients undergoing hip and knee arthroplasty under an enhanced recovery programme.

METHODS

Symptomatic VTE incidence was audited in 1,100 patients undergoing primary or revision total hip or knee arthroplasty at the same hospital with only mechanical prophylaxis from 2007 to 2009. Following addition of chemical prophylaxis (enoxaparin) symptomatic VTE incidence in 522 patients undergoing primary or revision total hip or knee arthroplasty from 2011 to 2012 was re-audited.

RESULTS

In the mechanical prophylaxis group incidence of DVT was 0.73 % [95 % confidence interval (CI) 0.37-1.43 %] and incidence of pulmonary embolism (PE) 0.91 % (95 % CI 0.49-1.67 %). Following addition of pharmacological prophylaxis incidence of DVT was 0.57 % (95 % CI 0.20-1.68 %) and incidence of PE 1.15 % (95 % CI 0.53-2.48 %).

CONCLUSIONS

We found no statistically significant difference in symptomatic VTE incidence following the addition of enoxaparin. We question whether routine pharmacological prophylaxis still has a role following total hip and knee arthroplasty. Peri-operative optimisation, including post-operative analgesia and mobility, with current enhanced recovery programmes may be sufficient. As anticoagulants carry increased risk of post-operative bleeding and wound ooze, in addition to significant cost implications, their role remains controversial.

Review article: Venous thromboembolism after total joint replacement

Venous thromboembolism can occur in up to 84% of cases following total joint replacement. It can result in pain, swelling, chronic post-thrombotic syndrome, and pulmonary embolism. Its prevention is vital to the success of the surgery. To achieve a safe and effective prophylaxis, a combination of mechanical and pharmacologic agents should be used. New generation of thromboprophylactic agents target different factors of the coagulation pathway.

Thromboprophylaxis for deep vein thrombosis and pulmonary embolism after total joint arthroplasty in a low incidence population

Postoperative venous thromboembolism is one of the most serious complications following total joint arthroplasty. Pharmacological and mechanical prophylaxis methods are used to reduce the risk of postoperative symptomatic deep vein thrombosis and pulmonary embolism. Use of pharmacological prophylaxis requires a fine balance between the efficacy of the drug in preventing deep vein thrombosis and the adverse effects associated with the use of these drugs. In regions with a low prevalence of deep vein thrombosis such as Korea, there might be a question whether the benefits of using pharmacological prophylaxis outweigh the risks involved. The current article reviews the need for thromboprophylaxis, guidelines, problems with the guidelines, pharmacological prophylaxis use, and the current scenario of deep vein thrombosis, and discusses whether the use of pharmacological prophylaxis should be mandatory in low incidence populations.

Is routine chemoprophylaxis necessary for prevention of venous thromboembolism following knee arthroplasty in a low incidence population?

BACKGROUND

Standard thromboprophylaxis guidelines have not been applied universally in regions with low incidence of deep-vein thrombosis (DVT) considering risks of chemoprophylaxis and low incidence itself. We evaluated the prevalence of DVT, efficacy and safety of chemoprophylaxis, and necessity of pharmacological prevention in a low DVT incidence population.

METHODS

One hundred and forty-eight patients undergoing unilateral total knee arthroplasty (TKA) were prospectively randomized to receive either a placebo or 2.5 mg of fondaparinux once daily for 5 days. Doppler ultrasonography was performed preoperatively and 7 days after surgery. The primary efficacy outcome was prevalence of DVT up to day 7. Secondary efficacy outcome was prevalence of symptomatic venous thromboembolism (VTE) up to day 90. Primary and secondary safety outcomes were incidence of major and minor bleeding, respectively.

RESULTS

The prevalence of total DVT was 25.7 % in placebo group and 6.8 % in fondaparinux group (p = 0.002) and the prevalence of proximal DVT was lower in both groups with no statistical difference. There was no symptomatic VTE in either group up to day 90. Although no major bleeding was developed, fondaparinux group had a significant increase of minor bleeding events (p < 0.001).

CONCLUSIONS

There remains low incidence of VTE following TKA in East Asians even without chemoprophylaxis. Although short-term fondaparinux protocol could reduce the incidence of overall DVT, its routine use seems debatable due to extremely rare proximal DVT and symptomatic PE and drug-related bleeding complication. However, modified and selective use of chemoprophylaxis would be considerable in high risk patients.

Chinese orthopedic surgeons' practice regarding postoperative thromboembolic prophylaxis after major orthopedic surgery

OBJECTIVE

To assess Chinese surgeon practice of thromboprophylaxis following major orthopedic surgery.

METHODS

A questionnaire survey was conducted amongst Chinese orthopedic surgeons. A total of 293 surgeons were surveyed concerning five key aspects of thromboembolic prophylaxis after major orthopedic surgery at the proseminar of Chinese guidelines for prevention of venous thromboembolism (VTE) after major orthopedic surgery in January of 2009.

RESULTS

Totally, 208 surgeons (71.0%) responded, successfully completing the questionnaire. Of them, 57.6% respondents selected combined basic, mechanical, and pharmacologic methods for thromboprophylaxis; 51.0% respondents prefer starting prophylaxis 12-24 hours after surgery; 60.3% surgeons would use chemoprophylaxis for 7-10 days; 47.6% respondents prefer VTE prevention based on patients' special conditions and needs upon discharge."Safety" was the most repeated and emphasized factor during VTE prophylaxis.

CONCLUSIONS

Multimodal thromboprophylaxis is frequently used after major orthopedic surgery. Half surgeons prefer to start chemoprophylaxis 12-24 hours after surgery. Thromboprophylaxis regimen varies for discharged patients.

Comparative effectiveness of low-molecular-weight heparins versus other anticoagulants in major orthopedic surgery: a systematic review and meta-analysis

STUDY OBJECTIVE

To evaluate the comparative efficacy and safety of low-molecular-weight heparins (LMWHs) versus other anticoagulants as venous thromboembolism prophylaxis in major orthopedic surgery.

DESIGN

Systematic review with meta-analysis of 37 randomized controlled trials.

PATIENTS

Patients undergoing total hip replacement, total knee replacement, or hip fracture surgery who received prophylaxis with a LMWH or another anticoagulant.

MEASUREMENTS AND MAIN RESULTS

We conducted a systematic literature search of the MEDLINE, Cochrane Central Register of Controlled Trials, and Scopus databases (1980-July 2011) to identify randomized controlled trials. Trials were included if they directly compared LMWH prophylaxis with another anticoagulant class and reported outcomes of interest. Compared with patients who received unfractionated heparin (UFH), patients who received LMWHs had fewer pulmonary embolism, total deep vein thrombosis (DVT), major bleeding, and heparin-induced thrombocytopenia events. Compared with patients who received vitamin K antagonists (VKAs), patients who received LMWHs had fewer total DVT and distal DVT events but reported increased major bleeding, minor bleeding, and surgical site bleeding events. Major efficacy end points such as symptomatic venous thromboembolism, pulmonary embolism, and nonfatal pulmonary embolism showed similar benefits of therapy with LMWHs and VKAs. Compared with patients receiving factor Xa inhibitors, patients who received LMWHs had more major venous thromboembolism, pulmonary embolism, total DVT, asymptomatic DVT, proximal DVT, and distal DVT events but fewer major bleeding events. Compared with patients receiving direct thrombin inhibitors (DTIs), patients who received LMWHs had more major venous thromboembolism, total DVT, and proximal DVT events without significantly negatively affecting bleeding. However, patients who received LMWHs had fewer distal DVT events versus those who received DTIs. Subgroup analyses indicated differences based on the surgical procedure and individual drug within certain pharmacologic classes.

CONCLUSION

According to moderate-to-high strength of evidence, LMWH prophylaxis provides additional benefits with less harm compared with UFH. With predominantly moderate strength of evidence, the balance of benefits to harms for factor Xa inhibitors or DTIs compared with LMWHs seems favorable. With predominantly low-to-moderate strength of evidence, the known benefits in total DVT and distal DVT with LMWHs versus VKAs may not be sufficient to counteract the increased risk of bleeding.

Combined (mechanical and pharmacological) modalities for the prevention of venous thromboembolism in joint replacement surgery

We performed a systematic review and meta-analysis to compare the efficacy of intermittent mechanical compression combined with pharmacological thromboprophylaxis, against either mechanical compression or pharmacological prophylaxis in preventing deep-vein thrombosis (DVT) and pulmonary embolism in patients undergoing hip or knee replacement. A total of six randomised controlled trials, evaluating a total of 1399 patients, were identified. In knee arthroplasty, the rate of DVT was reduced from 18.7% with anticoagulation alone to 3.7% with combined modalities (risk ratio (RR) 0.27, p = 0.03; number needed to treat: seven). There was moderate, albeit non-significant, heterogeneity (I2 = 42%). In hip replacement, there was a non-significant reduction in DVT from 8.7% with mechanical compression alone to 7.2% with additional pharmacological prophylaxis (RR 0.84) and a significant reduction in DVT from 9.7% with anticoagulation alone to 0.9% with additional mechanical compression (RR 0.17, p < 0.001; number needed to treat: 12), with no heterogeneity (I2 = 0%). The included studies had insufficient power to demonstrate an effect on pulmonary embolism.

We conclude that the addition of intermittent mechanical leg compression augments the efficacy of anticoagulation in preventing DVT in patients undergoing both knee and hip replacement. Further research on the role of combined modalities in thromboprophylaxis in joint replacement and in other high-risk situations, such as fracture of the hip, is warranted.

Experimental Validation of Methods for Prophylaxis against Deep Venous Thrombosis: A Review and Proposal

The experimental procedure by which the valve cusp hypoxia (VCH) hypothesis of the etiology of deep venous thrombosis (DVT) was confirmed lends itself to testing of methods of prophylaxis. Similar animal experiments could end the present exclusive reliance on statistical analysis of data from large patient cohorts to evaluate prophylactic regimes. The reduction of need for such (usually retrospective) analyses could enable rationally-based clinical trials of prophylactic methods to be conducted more rapidly, and the success of such trials would lead to decreased incidences of DVT-related mortality and morbidity. This paper reviews the VCH hypothesis ("VCH thesis", following its corroboration) and its implications for understanding DVT and its sequelae, and outlines the experimental protocol for testing prophylactic methods. The advantages and limitations of the protocol are briefly discussed.