Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review

Venous Thromboembolism Prophylaxis in Obstetric Patients

Venous thromboembolism (VTE), including both pulmonary embolism (PE) and deep vein thrombosis (DVT), is the leading cause of maternal death in developed countries. Pregnancy is associated with an increased risk of VTE due to physiologic changes during the obstetric period that promote a hypercoagulable state. Appropriate use of prophylactic anticoagulants can decrease the event rate of thrombus formation in at-risk patients. In the United States, there is not a validated risk-assessment tool for VTE in obstetric patients or a clear consensus on initiation and optimal dosing strategy for the prophylactic use of anticoagulants. This article reviews the mechanism of coagulation disturbance that leads to an increased risk of VTE in obstetric patients, as well as the available literature surrounding pharmacologic prophylaxis.

Deep Vein Thrombosis Prophylaxis in Orthopedic Surgery

Deep vein thrombosis (DVT) is a complex and multifactorial process arising from a variety of factors, including recent surgical procedures, traumatic events, and periods of prolonged immobility. The extended period of stasis post-orthopedic surgery places patients at a notably high risk of developing DVT, and DVT-related pulmonary embolism (PE) ranks as the third most common cause of death in orthopedic surgery patients. This review examines the multifaceted risk factors contributing to the development of DVT in orthopedic patients. Additionally, it addresses the importance of DVT prophylaxis in orthopedic settings, the efficacy and safety of various prophylactic methods encompassing both mechanical and pharmacological approaches, and the economic dimensions of DVT prophylaxis, including scrutiny of cost-effectiveness and the exploration of strategies for optimization.

Venous Thromboembolism Prophylaxis in Major Orthopedic Surgeries and Factor XIa Inhibitors

Venous thromboembolism (VTE), comprising pulmonary embolism (PE) and deep vein thrombosis (DVT), poses a significant risk during and after hospitalization, particularly for surgical patients. Among various patient groups, those undergoing major orthopedic surgeries are considered to have a higher susceptibility to PE and DVT. Major lower-extremity orthopedic procedures carry a higher risk of symptomatic VTE compared to most other surgeries, with an estimated incidence of ~4%. The greatest risk period occurs within the first 7-14 days following surgery. Major bleeding is also more prevalent in these surgeries compared to others, with rates estimated between 2% and 4%. For patients undergoing major lower-extremity orthopedic surgery who have a low bleeding risk, it is recommended to use pharmacological thromboprophylaxis with or without mechanical devices. The choice of the initial agent depends on the specific surgery and patient comorbidities. First-line options include low-molecular-weight heparins (LMWHs), direct oral anticoagulants, and aspirin. Second-line options consist of unfractionated heparin (UFH), fondaparinux, and warfarin. For most patients undergoing knee or hip arthroplasty, the initial agents recommended for the early perioperative period are LMWHs (enoxaparin or dalteparin) or direct oral anticoagulants (rivaroxaban or apixaban). In the case of hip fracture surgery, LMWH is recommended as the preferred agent for the entire duration of prophylaxis. However, emerging factor XI(a) inhibitors, as revealed by a recent meta-analysis, have shown a substantial decrease in the occurrence of VTE and bleeding events among patients undergoing major orthopedic surgery. This discovery poses a challenge to the existing paradigm of anticoagulant therapy in this specific patient population and indicates that factor XI(a) inhibitors hold great promise as a potential strategy to be taken into serious consideration.

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis.

Joint 2022 European Society of Thoracic Surgeons and The American Association for Thoracic Surgery guidelines for the prevention of cancer-associated venous thromboembolism in thoracic surgery

BACKGROUND

Venous thromboembolism (VTE), which includes deep vein thrombosis and pulmonary embolism, is a potentially fatal but preventable postoperative complication. Thoracic oncology patients undergoing surgical resection, often after multimodality induction therapy, represent among the highest risk groups for postoperative VTE. Currently there are no VTE prophylaxis guidelines specific to these thoracic surgery patients. Evidenced-based recommendations will help clinicians manage and mitigate risk of VTE in the postoperative period and inform best practice.

OBJECTIVE

These joint evidence-based guidelines from The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons aim to inform clinicians and patients in decisions about prophylaxis to prevent VTE in patients undergoing surgical resection for lung or esophageal cancer.

METHODS

The American Association for Thoracic Surgery and the European Society of Thoracic Surgeons formed a multidisciplinary guideline panel that included broad membership to minimize potential bias when formulating recommendations. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used, including GRADE Evidence-to-Decision frameworks, which were subject to public comment.

RESULTS

The panel agreed on 24 recommendations focused on pharmacological and mechanical methods for prophylaxis in patients undergoing lobectomy and segmentectomy, pneumonectomy, and esophagectomy, as well as extended resections for lung cancer.

CONCLUSIONS

The certainty of the supporting evidence for the majority of recommendations was judged as low or very low, largely due to a lack of direct evidence for thoracic surgery. The panel made conditional recommendations for use of parenteral anticoagulation for VTE prevention, in combination with mechanical methods, over no prophylaxis for cancer patients undergoing anatomic lung resection or esophagectomy. Other key recommendations include: conditional recommendations for using parenteral anticoagulants over direct oral anticoagulants, with use of direct oral anticoagulants suggested only in the context of clinical trials; conditional recommendation for using extended prophylaxis for 28 to 35 days over in-hospital prophylaxis only for patients at moderate or high risk of thrombosis; and conditional recommendations for VTE screening in patients undergoing pneumonectomy and esophagectomy. Future research priorities include the role of preoperative thromboprophylaxis and the role of risk stratification to guide use of extended prophylaxis. (J Thorac Cardiovasc Surg 2022;▪:1-31).

Preventing Venous Thromboembolism after elective total hip arthroplasty surgery - are the current guidelines appropriate? Venous thromboembolism prophylaxis in elective total hip arthroplasty surgery

INTRODUCTION

Venous Thromboembolism after elective Total Hip Arthroplasty surgery is a well-recognised complication, resulting in fatal pulmonary embolism, post thrombotic syndrome and recurrent thrombotic episodes. Guidelines developed by clinical organisations attempt to provide evidence-based recommendations to clinicians.

METHODS

This narrative review evaluated the current available literature in relation to the available guidelines, to evaluate whether the current major guidelines reflect the evidence base. All major clinical guidelines were collated through database searching, alongside the relevant clinical studies.

PRINCIPAL FINDINGS

The promotion of a multi-modal approach, combining mechanical and chemical prophylaxis, does appear to be well validated, with mechanical prophylaxis offering positive clinical effects with little negative clinical consequence. Within the current guidelines surrounding VTE prevention in the elective-THA patient, there does appear to be a lack of prescription in relation to risk stratification and adopting personalised approaches for specific patient subsets.

CONCLUSION

We suggest moving away from protocolisation of VTE prevention, given the evidence base is not fully developed to allow a 'one-size-fits-all' approach.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations: A 2021 Update

Background

This is the second updated Enhanced Recovery After Surgery (ERAS®) Society guideline, presenting a consensus for optimal perioperative care in bariatric surgery and providing recommendations for each ERAS item within the ERAS® protocol.

Methods

A principal literature search was performed utilizing the Pubmed, EMBASE, Cochrane databases and ClinicalTrials.gov through December 2020, with particular attention paid to meta-analyses, randomized controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded according to the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system. After critical appraisal of these studies, the group of authors reached consensus regarding recommendations.

Results

The quality of evidence for many ERAS interventions remains relatively low in a bariatric setting and evidence-based practices may need to be extrapolated from other surgeries.

Conclusion

A comprehensive, updated evidence-based consensus was reached and is presented in this review by the ERAS® Society.

A risk-stratified approach to venous thromboembolism prophylaxis with aspirin or warfarin following total hip and knee arthroplasty: A cohort study

INTRODUCTION

Venous thromboembolism (VTE) and bleeding events following total knee and hip arthroplasty (TKA/THA) are associated with significant morbidity. Clinical guidelines recommend administration of pharmacologic VTE prophylaxis post-operatively, although controversy exists regarding optimal prophylactic strategies.

METHODS

We performed a retrospective cohort study in patients who underwent elective TKA/TKA in an academic medical center. Patients were stratified by surgery type (TKA/THA) and VTE risk determined by a novel risk stratification protocol and compared pre- and post-protocol implementation. Patients received warfarin pre-protocol and either aspirin or warfarin post-protocol for VTE prophylaxis. Natural language processing identified VTE events and ICD codes were used to identify bleeding events, with all events validated manually.

RESULTS

A total of 1379 surgeries were included for analysis, 839 TKAs and 540 THAs. Post-protocol implementation, 445 (94.1%) patients following TKA and 294 (97.4%) patients following THA received aspirin for VTE prophylaxis. A significant reduction in bleeding events (hazard ratio [HR] = 0.19, p = 0.048) was observed in low-risk THA patients treated with aspirin (post-protocol) compared patients treated with warfarin (pre-protocol). Bleeding events did not differ significantly between low-risk TKA patients treated with aspirin or warfarin. No significant differences in VTE events were observed following the protocol implementation.

CONCLUSIONS

The use of a novel risk stratification system to guide VTE prophylaxis selection between aspirin or warfarin following TKA and THA appears safe and effective. Among low-risk patients, aspirin use was associated with fewer bleeding events following THA, without an observed increase in VTE events.

Is Apixaban Safe and Effective for Venous Thromboembolism Prophylaxis After Primary Total Hip and Total Knee Arthroplasties?

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of total hip arthroplasty (THA) and total knee arthroplasty (TKA). Apixaban is approved for VTE prophylaxis. This study seeks to ascertain the risk of VTE and bleeding complications in patients undergoing primary THA and TKA receiving apixaban for postoperative VTE prophylaxis for one of the following indications: high risk for VTE, previously on apixaban, and contraindication to the use of aspirin.

METHODS

This is a retrospective cohort study of patients who underwent primary THA or TKA over a 17-month period and were prescribed apixaban for thromboprophylaxis postoperatively.

RESULTS

230 patients were included in the study, 110 TKA and 120 THA. The primary reasons for high-risk VTE status included personal and family history of VTE, and 13% were taking apixaban preoperatively for atrial fibrillation. 1 patient (0.43%) who underwent TKA had a DVT with PE. 2.6% of patients had wound complications requiring operative treatment, and 0.87% of THA patients underwent revision arthroplasty.

CONCLUSION

The use of apixaban for VTE prophylaxis after primary THA and TKA in patients at high risk for VTE, in patients previously on apixaban, and in patients with a contraindication to the use of aspirin is associated with a low risk of VTE and bleeding complications.

Venous thromboembolism prophylaxis in high-risk orthopedic and cancer surgery

Orthopedic surgery and surgery for cancer are major risk factors for venous thromboembolism (VTE). Deep vein thrombosis (DVT) can occur in up to 50% of patients after major orthopedic surgery. The rate of VTE after cancer surgery varies according to the type of surgery, with rates as high as those after orthopedic surgery in certain settings. Use of thromboprophylaxis in these high-risk settings is well established and recent studies inform the type and duration of thromboprophylaxis. With major orthopedic surgery, there has been a shift from use of low molecular weight heparins (LMWHs) to direct oral anticoagulants (DOACs) along with renewed interest in aspirin as a thromboprophylaxis agent. Recent studies have also informed optimal thromboprophylaxis strategies after nonmajor orthopedic surgery. Use of thromboprophylaxis after major cancer surgery for cancer is established and recent evidence has focused on the potential benefits of extended-duration thromboprophylaxis. This review will summarize emerging evidence for thromboprophylaxis after orthopedic and cancer surgery with a view to providing clinicians with concise and actionable guidance for best practice.

Society of Family Planning clinical recommendations: Management of individuals with bleeding or thrombotic disorders undergoing abortion

Individuals who have bleeding disorders, thrombophilias, a history of venous thromboembolism (VTE), or who are taking anticoagulation medication for other reasons may present for abortion. Clinicians should be aware of risk factors and histories concerning for excessive bleeding and thrombotic disorders around the time of abortion. This document will focus on how to approach abortion planning in these individuals. For first-trimester abortion, procedural abortion (sometimes called surgical abortion) is generally preferred over medical management for individuals with bleeding disorders or who are on anticoagulation. First-trimester procedural abortion in an individual on anticoagulation can generally be done without interruption of anticoagulation. The decision to interrupt anticoagulation for a second-trimester procedure should be individualized. Individuals at high risk for VTE can be offered anticoagulation post-procedure. Individuals with bleeding disorders or who are anticoagulated can safely be offered progestin intrauterine devices. Future research is needed to better assess quantitative blood loss and complications rates with abortion in these populations.

Pulmonary Embolism in Pregnancy

Even though venous thromboembolism is a leading cause of maternal mortality in high-income countries, there are limited high-quality data to assist clinicians with the management of pulmonary embolism in this patient population. Diagnosis, prevention, and treatment of pregnancy-associated pulmonary embolism are complicated by the need to consider fetal, as well as maternal, well-being. Recent studies suggest that clinical prediction rules and D-dimer testing can reduce the need for diagnostic imaging in a subset of patients. Low-molecular-weight heparin is the preferred anticoagulant for both prophylaxis and treatment in this setting. Direct oral anticoagulants are contraindicated during pregnancy and in breastfeeding women. Thrombolysis or embolectomy should be considered for pregnant women with pulmonary embolism complicated by hemodynamic instability. Treatment of pregnancy-associated pulmonary embolism should be continued for at least 3 months, including 6 weeks postpartum. Management of anticoagulants at the time of delivery should involve a multidisciplinary individualized approach that uses shared decision making to take patient and caregiver values and preferences into account.

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.

Comparison of the Efficacy and Safety of Aspirin and Rivaroxaban Following Enoxaparin Treatment for Prevention of Venous Thromboembolism after Hip Fracture Surgery

OBJECTIVE

To compare the efficacy and safety of aspirin with rivaroxaban following treatment with enoxaparin for prevention of venous thromboembolism (VTE) after hip fracture surgery (HFS).

METHODS

A total of 390 patients were enrolled in the trial. According to an odd or even number at the end of their registration number, the patients were divided into the aspirin group (n = 198) and the rivaroxaban group (n = 192). All patients were given enoxaparin subcutaneous injection after the operation and returned to the routine dose the next day until postoperative day five. The patients in the aspirin group received an additional 16 days of thromboprophylaxis with 100 mg of aspirin once daily. The rivaroxaban group was assigned to receive an additional 16 days of thromboprophylaxis with 10 mg of oral rivaroxaban once daily. Patients were followed for 90 days regarding VTE and bleeding complications.

RESULTS

The incidence of VTE in the aspirin group and rivaroxaban group was 6.6% (13/198) and 5.7% (11/192), respectively (P = 0.83). The rate of major bleeding events occurred in two (1.0%) patients in the aspirin group and in one patient (0.5%) in the rivaroxaban group (P = 1.0). A combination of major bleeding and clinically relevant nonmajor bleeding occurred in five patients (2.5%) in the aspirin group and in six patients (3.1%) in the rivaroxaban group (P = 0.77). During the 90-day follow-up, a pulmonary embolism developed in one patient (0.5%) in the aspirin group and none in the rivaroxaban group (P = 1.0).

CONCLUSIONS

Extended prophylaxis for 21 days with aspirin was equivalent to the direct oral anticoagulant rivaroxaban after hip fracture surgery with an initial 5-day postoperative course of enoxaparin. Aspirin may be an effective, safe, convenient, and cheap alternative for extended prophylaxis after hip fracture surgery.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy

BACKGROUND

Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis.

CONCLUSIONS

There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery

BACKGROUND

This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery.

OBJECTIVES

To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE.

SEARCH METHODS

We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies.

SELECTION CRITERIA

We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation.

DATA COLLECTION AND ANALYSIS

Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications and mortality within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis.

MAIN RESULTS

We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I² = 28%; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I² = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I² = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis, which approached significance (M-H OR 0.30, 95% CI 0.08 to 1.11; I² = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (M-H OR 1.10, 95% CI 0.67 to 1.81; I² = 0%; moderate-quality evidence).No difference in mortality between the control and LMWH group was found, 3.8% and 3.9%, respectively (M-H OR 1.15, 95% CI 0.72 to 1.84; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity.

AUTHORS' CONCLUSIONS

Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications or mortality after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

Optimal duration of anticoagulant thromboprophylaxis in total hip arthroplasty: new evidence in 55,540 patients with osteoarthritis from the Nordic Arthroplasty Register Association (NARA) group

Background and purpose - The recommended optimal duration of the thromboprophylaxis treatment in total hip arthroplasty (THA) patients has been a matter of debate for years. We examined the association between short (1-5 days), standard (6-14 days), and extended (≥ 15 days) duration of thromboprophylaxis, with regards to the risk of venous thromboembolism (VTE), major bleeding, and death in unselected THA patients. Patients and methods - We performed a cohort study using prospectively collected data from the population-based hip arthroplasty registries, prescription databases, and patient administrative registries in Denmark and Norway. We included 55,540 primary THA patients with osteoarthritis Results - The 90-day cumulative incidence of VTE was 1.0% for patients with standard treatment (reference), 1.1% for those with short-term treatment (adjusted hazard ratio [aHR] of 1.1, 95% confidence interval (CI) 0.8-1.5) and 1.0% for those with extended treatment (aHR of 0.9, CI 0.8-1.2). The aHRs for major bleeding were 1.1 (CI 0.8-1.6) for short and 0.8 (CI 0.6-1.1) for extended vs. standard treatment. In addition, patients with short and extended treatment had aHRs for death of 1.2 (CI 0.8-1.8) and 0.8 (CI 0.5-1.1) vs. standard treatment, respectively. Patients who started short treatment postoperatively had an aHR for death of 1.8 (CI 1.1-3.1) and absolute risk difference of 0.2%, whereas patients who started short treatment preoperatively had an aHR for death of 0.5 (CI 0.2-1.2) and absolute risk difference of 0.3% compared with patients who had standard treatment with post- and preoperative start, respectively. Interpretation - In routine clinical practice, we observed no overall clinically relevant difference in the risks of VTE and major bleeding within 90 days of THA with respect to thromboprophylaxis duration. However, our data indicate that short-term thromboprophylaxis started postoperatively is associated with increased 90-day mortality. The significance of these data should be explored further.

A clinical predictive model for post-hospitalisation venous thromboembolism in patients with inflammatory bowel disease

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of venous thromboembolism (VTE) during hospitalisation and potentially post-discharge.

AIMS

To determine the incidence and risk factors for post-discharge VTE in IBD patients and create a point of care predictive model to assess VTE risk.

METHODS

Hospitalised IBD patients were identified from our institutional discharge database between 2009 and 2016, and were assessed for VTE by chart review. Risk factors for VTE within 3 months of discharge were determined by univariable and multivariable logistic regression. A point of care model was created using variables from the univariate analysis with P < 0.05, and internally validated by bootstrap methods.

RESULTS

Sixty-six of 2161 eligible discharges (3%) were associated with VTE within 6 months of hospitalisation. The median time to event was 37 days (range 3-182 days). On multivariable analysis age >45 years (OR 3.76; 95% CI 1.80-7.89) and multiple admissions (OR 2.62; 95% CI 1.34-5.11) were independently associated with VTE risk. Our final model incorporated age >45 years, multiple admissions, intensive care unit admission, length of admission >7 days and central catheter and was able to discriminate between discharges associated with and without VTE (optimism-corrected c-statistic, 0.70; 95% CI 0.58-0.77). By limiting treatment to a high-risk group, extended thromboprophylaxis could be avoided in 92% of discharges with a miss rate of 1.6% (32/1982 discharges).

CONCLUSION

Patients with IBD remain at risk of VTE after hospital discharge. Our model may help clinicians stratify which patients will benefit most from extended thrombophrophylaxis.

Patient compliance with deep vein thrombosis prophylaxis after total hip and total knee arthroplasty

Even though the Centers for Medicare and Medicaid Services is penalizing hospitals for readmissions, and postoperative prophylaxis has demonstrated reduced complications associated with deep vein thrombosis (DVT), few studies have examined patient compliance with (DVT) prophylaxis at home. A survey querying DVT prophylaxis management and adherence was administered to patients who were within the one to three-month postoperative period after a total knee or total hip replacement. A total of 103 patients completed the survey. A considerable number of patients (17.0%) were non-adherent to DVT prophylaxis. Patients had a lower understanding of the side effects of their DVT prophylaxis, with 30% responding that they had a poor to simple understanding. There is a high rate of non-compliance and there is a poor understanding of complications related to venous thromboembolism prophylaxis. As the population undergoing arthroplasties grows, this study demonstrates the importance of investigating the role of medication adherence in the rate of postoperative DVT.

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.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery

BACKGROUND

This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery.

OBJECTIVES

To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE.

SEARCH METHODS

We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies.

SELECTION CRITERIA

We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation.

DATA COLLECTION AND ANALYSIS

Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications and mortality within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis.

MAIN RESULTS

We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I² = 28%; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I² = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I² = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis (M-H OR 0.30, 95% CI 0.08 to 1.11; I² = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (M-H OR 1.10, 95% CI 0.67 to 1.81; I² = 0%; moderate-quality evidence).No difference in mortality between the control and LMWH group was found, 3.8% and 3.9%, respectively (M-H OR 1.15, 95% CI 0.72 to 1.84; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity.

AUTHORS' CONCLUSIONS

Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications or mortality after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

The Impact of Evidence in Surgery of the Musculoskeletal System

There have been a growing number of landmark randomized controlled trials published in the orthopedic literature over the past decade. These large-scale trials have had a substantial impact on informing clinical orthopedic practice globally. This review highlights a selected sample of such pivotal trials, across the subspecialties of trauma, sports medicine, arthroplasty, spine, and the important topic of intimate partner violence.

Extended-duration betrixaban versus shorter-duration enoxaparin for venous thromboembolism prophylaxis in critically ill medical patients: an APEX trial substudy

PURPOSE

To assess the efficacy and safety of betrixaban for venous thromboembolism (VTE) prophylaxis among critically ill patients.

METHODS

The APEX trial randomized 7513 acutely ill hospitalized patients to betrixaban for 35-42 days or enoxaparin for 10 ± 4 days. Among those, 703 critically ill patients admitted to the intensive care unit were included in the analysis, and 547 patients who had no severe renal insufficiency or P-glycoprotein inhibitor use were included in the full-dose stratum. The risk of VTE, bleeding, net clinical benefit (composite of VTE and major bleeding), and mortality was compared at 35-42 days and at 77 days.

RESULTS

At 35-42 days, extended betrixaban reduced the risk of VTE (4.27% vs 7.95%, P = 0.042) without causing excess major bleeding (1.14% vs 3.13%, P = 0.07). Both VTE (3.32% vs 8.33%, P = 0.013) and major bleeding (0.00% vs 3.26%, P = 0.003) were decreased in the full-dose stratum. Patients who received betrixaban had more non-major bleeding than enoxaparin (overall population: 2.56% vs 0.28%, P = 0.011; full-dose stratum: 3.32% vs 0.36%, P = 0.010). Mortality was similar at the end of study (overall population: 13.39% vs 16.19%, P = 0.30; full-dose stratum: 13.65% vs 16.30%, P = 0.39).

CONCLUSIONS

Compared with shorter-duration enoxaparin, critically ill medical patients who received extended-duration betrixaban had fewer VTE without more major bleeding events. The benefit of betrixaban was driven by preventing asymptomatic thrombosis and offset by an elevated risk of non-major bleeding. The APEX trial did not stratify by intensive care unit admission and the present study included a highly selected population of critically ill patients. These hypothesis-generating findings need to be validated in future studies.

CLINICAL TRIAL REGISTRATION

http://www.clinicaltrials.gov . Unique identifier: NCT01583218.

Prolonged thromboprophylaxis with low molecular weight heparin for abdominal or pelvic surgery

BACKGROUND

This an update of the review first published in 2009.Major abdominal and pelvic surgery carries a high risk of venous thromboembolism (VTE). The efficacy of thromboprophylaxis with low molecular weight heparin (LMWH) administered during the in-hospital period is well-documented, but the optimal duration of prophylaxis after surgery remains controversial. Some studies suggest that patients undergoing major abdominopelvic surgery benefit from prolongation of the prophylaxis up to 28 days after surgery.

OBJECTIVES

To evaluate the efficacy and safety of prolonged thromboprophylaxis with LMWH for at least 14 days after abdominal or pelvic surgery compared with thromboprophylaxis administered during the in-hospital period only in preventing late onset VTE.

SEARCH METHODS

We performed electronic searches on 28 October 2017 in the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, LILACS and registered trials (Clinicaltrials.gov October 28, 2017 and World Health Organization International Clinical Trials Registry Platform (ICTRP) 28 October 2017). Abstract books from major congresses addressing thromboembolism were handsearched from 1976 to 28 October 2017, as were reference lists from relevant studies.

SELECTION CRITERIA

We assessed randomized controlled clinical trials (RCTs) comparing prolonged thromboprophylaxis (≥ fourteen days) with any LMWH agent with placebo, or other methods, or both to thromboprophylaxis during the admission period only. The population consisted of persons undergoing abdominal or pelvic surgery for both benign and malignant pathology. The outcome measures included VTE (deep venous thrombosis (DVT) or pulmonary embolism (PE)) as assessed by objective means (venography, ultrasonography, pulmonary ventilation/perfusion scintigraphy, spiral computed tomography (CT) scan or autopsy). We excluded studies exclusively reporting on clinical diagnosis of VTE without objective confirmation.

DATA COLLECTION AND ANALYSIS

Review authors identified studies and extracted data. Outcomes were VTE (DVT or PE) assessed by objective means. Safety outcomes were defined as bleeding complications within three months after surgery. Sensitivity analyses were also performed with unpublished studies excluded, and with study participants limited to those undergoing solely open and not laparoscopic surgery. We used a fixed-effect model for analysis.

MAIN RESULTS

We identified seven RCTs (1728 participants) evaluating prolonged thromboprophylaxis with LMWH compared with control or placebo. The searches resulted in 1632 studies, of which we excluded 1528. One hundred and four abstracts, eligible for inclusion, were assessed of which seven studies met the inclusion criteria.For the primary outcome, the incidence of overall VTE after major abdominal or pelvic surgery was 13.2% in the control group compared to 5.3% in the patients receiving out-of-hospital LMWH (Mantel Haentzel (M-H) odds ratio (OR) 0.38, 95% confidence interval (CI) 0.26 to 0.54; I² = 28%; seven studies, n = 1728; moderate-quality evidence).For the secondary outcome of all DVT, seven studies, n = 1728, showed prolonged thromboprophylaxis with LMWH to be associated with a statistically significant reduction in the incidence of all DVT (M-H OR 0.39, 95% CI 0.27 to 0.55; I² = 28%; moderate-quality evidence).We found a similar reduction when analysis was limited to incidence in proximal DVT (M-H OR 0.22, 95% CI 0.10 to 0.47; I² = 0%; moderate-quality evidence).The incidence of symptomatic VTE was also reduced from 1.0% in the control group to 0.1% in patients receiving prolonged thromboprophylaxis (M-H OR 0.30, 95% CI 0.08 to 1.11; I² = 0%; moderate-quality evidence).No difference in the incidence of bleeding between the control and LMWH group was found, 2.8% and 3.4%, respectively (HM-H OR 1.10, 95% CI 0.67 to 1.81; I² = 0%; seven studies, n = 2239; moderate-quality evidence).Estimates of heterogeneity ranged between 0% and 28% depending on the analysis, suggesting low or unimportant heterogeneity.

AUTHORS' CONCLUSIONS

Prolonged thromboprophylaxis with LMWH significantly reduces the risk of VTE compared to thromboprophylaxis during hospital admittance only, without increasing bleeding complications after major abdominal or pelvic surgery. This finding also holds true for DVT alone, and for both proximal and symptomatic DVT. The quality of the evidence is moderate and provides moderate support for routine use of prolonged thromboprophylaxis. Given the low heterogeneity between studies and the consistent and moderate evidence of a decrease in risk for VTE, our findings suggest that additional studies may help refine the degree of risk reduction but would be unlikely to significantly influence these findings. This updated review provides additional evidence and supports the previous results reported in the 2009 review.

Low molecular weight heparin versus other anti-thrombotic agents for prevention of venous thromboembolic events after total hip or total knee replacement surgery: a systematic review and meta-analysis

Background

Venous thromboembolism (VTE) is an important complication following total hip replacement (THR) and total knee replacement (TKR) surgeries. Aim of this study was to comprehensively compare the clinical outcomes of low-molecular-weight heparin (LMWH) with other anticoagulants in patients who underwent TKR or THR surgery.

Methods

Medline, Cochrane, EMBASE, and Google Scholar databases were searched for eligible randomized controlled studies (RCTs) published before June 30, 2017. Meta-analyses of odds ratios were performed along with subgroup and sensitivity analyses.

Results

Twenty-one RCTs were included. In comparison with placebo, LMWH treatment was associated with a lower risk of VTE and deep vein thrombosis (DVT) (P values < 0.001) but similar risk of pulmonary embolism (PE) (P = 0.227) in THR subjects. Compared to factor Xa inhibitors, LMWH treatment was associated with higher risk of VTE in TKR subjects (P < 0.001), and higher DVT risk (P < 0.001) but similar risk of PE and major bleeding in both THR and TKR. The risk of either VTE, DVT, PE, or major bleeding was similar between LMWH and direct thrombin inhibitors in both THR and TKR, but major bleeding was lower with LMWH in patients who underwent THR (P = 0.048).

Conclusion

In comparison with factor Xa inhibitors, LMWH may have higher risk of VTE and DVT, whereas compared to direct thrombin inhibitors, LMWH may have lower risk of major bleeding after THR or TKR.

Electronic supplementary material

The online version of this article (10.1186/s12891-018-2215-3) contains supplementary material, which is available to authorized users.

Is thromboprophylaxis cost effective in ovarian hyperstimulation syndrome: A systematic review and cost analysis

BACKGROUND

The majority of serious thromboembolic events occurring in assisted reproductive technologies (ART) are in women with ovarian hyperstimulation syndrome (OHSS).

OBJECTIVES

The purpose of this study was to present a thorough review and cost analysis regarding the use of venous thromboembolism (VTE) prophylaxis in OHSS to inform clinical management.

DATA SOURCES

Databases used were Pubmed and Embase, in addition to checking reference lists of retrieved articles (inception to November 2017).

METHODS

The systematic search strategy identified 365 titles and abstracts. Articles included in the qualitative synthesis had identified venous thrombosis incidence rates or ratios. A separate search for the cost model was conducted recognizing all associated complications of VTE. The decision tree was modeled to best fit the patient population and a sensitivity analysis was performed over a range of variables.

RESULTS

The cost of VTE event per OHSS patient not on prophylaxis was €5940 (range €3405 to €38,727), versus €4134 (€2705 to €23,192) per event per patient on prophylaxis, amounting to a saving of (€19 to €23,192) per VTE per patient. Sensitivity analysis found VTE prophyaxis to be cost effective if the incidence of VTE in the OHSS population was greater than 2.79%. Prophylactic therapy was cost effective through 16 weeks of treatment.

LIMITATIONS

OHSS is infrequent and hence, the incidence of VTE in patients with OHSS is low; therefore, the data used to inform the incidence of VTE in OHSS in the model carry some uncertainty. Further, low molecular weight heparin (LMWH) has side effects therefore individualization of care must be considered.

CONCLUSIONS

With the increasing incidence of infertility and requirement for ART, thromboembolism in OHSS poses a major health threat for patients. VTE prophylaxis using enoxaparin was cost effective in patients with severe OHSS over a wide range of costs and incidences. Prophylaxis was also cost effective through the completion of the first trimester of pregnancy.

Aspirin or Rivaroxaban for VTE Prophylaxis after Hip or Knee Arthroplasty

BACKGROUND

Clinical trials and meta-analyses have suggested that aspirin may be effective for the prevention of venous thromboembolism (proximal deep-vein thrombosis or pulmonary embolism) after total hip or total knee arthroplasty, but comparisons with direct oral anticoagulants are lacking for prophylaxis beyond hospital discharge.

METHODS

We performed a multicenter, double-blind, randomized, controlled trial involving patients who were undergoing total hip or knee arthroplasty. All the patients received once-daily oral rivaroxaban (10 mg) until postoperative day 5 and then were randomly assigned to continue rivaroxaban or switch to aspirin (81 mg daily) for an additional 9 days after total knee arthroplasty or for 30 days after total hip arthroplasty. Patients were followed for 90 days for symptomatic venous thromboembolism (the primary effectiveness outcome) and bleeding complications, including major or clinically relevant nonmajor bleeding (the primary safety outcome).

RESULTS

A total of 3424 patients (1804 undergoing total hip arthroplasty and 1620 undergoing total knee arthroplasty) were enrolled in the trial. Venous thromboembolism occurred in 11 of 1707 patients (0.64%) in the aspirin group and in 12 of 1717 patients (0.70%) in the rivaroxaban group (difference, 0.06 percentage points; 95% confidence interval [CI], -0.55 to 0.66; P<0.001 for noninferiority and P=0.84 for superiority). Major bleeding complications occurred in 8 patients (0.47%) in the aspirin group and in 5 (0.29%) in the rivaroxaban group (difference, 0.18 percentage points; 95% CI, -0.65 to 0.29; P=0.42). Clinically important bleeding occurred in 22 patients (1.29%) in the aspirin group and in 17 (0.99%) in the rivaroxaban group (difference, 0.30 percentage points; 95% CI, -1.07 to 0.47; P=0.43).

CONCLUSIONS

Among patients who received 5 days of rivaroxaban prophylaxis after total hip or total knee arthroplasty, extended prophylaxis with aspirin was not significantly different from rivaroxaban in the prevention of symptomatic venous thromboembolism. (Funded by the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT01720108 .).

The Prophylaxis of Venous Thromboembolism

BACKGROUND

Venous thromboembolism (VTE) is the third most common cardiovascular condition, after myocardial infarction and stroke. Prophylactic measures in accordance with current guidelines can significantly reduce the risk of VTE and the associated morbidity and mortality. Until now, the German interdisciplinary, evidence- and consensus-based (S3) clinical practice guideline on VTE prophylaxis was based on a complete review of all pertinent literature available in MEDLINE up to January 2008. More recent publications and drug approvals have made a thorough revision necessary.

METHODS

A systematic search was carried out in the MEDLINE and Embase databases for publications that appeared from 1 January 2008 to 7 August 2013. Updates of 5 national and international reference guidelines and 2 new Health Technology Assessment (HTA) reports were considered as well. A structured consensus-finding process was carried out with delegates from 27 scientific medical societies and from the Union of Medical Specialist Associations.

RESULTS

46 randomized controlled trials (RCTs) were included for critical appraisal. New findings led to re-evaluation of the value of compression stockings in combination with pharmacological prophylaxis (open recommendation), and suggest equal value of non-vitamin K antagonist oral anticoagulants (NOACs) and low molecular weight heparins (LMWH) or fondaparinux in elective hip and knee replacement (strong recommendation). For patients undergoing hip fracture surgery, we recommend LMWH or fondaparinux.

CONCLUSION

Further research is needed to assess the value of NOACs for pharmacological prophylaxis in orthopedic/trauma patients undergoing surgical procedures other than the ones mentioned above, and into the benefit and harm of new devices available for mechanical prophylaxis. The stringent implementation of basic measures such as early mobilization, movement exercises, and patient instruction is a key point to prevent venous thrombo - embolism.

Can thrombus age guide thrombolytic therapy?

Venous thrombosis (VT) is a common yet complex clinical condition that has shown minimal alteration in clinical management for decades. It is well known that thrombus evolves structurally over time, with complex changes resulting from the interplay between coagulation factors, cytokines, leukocytes and a myriad of other factors. Our current treatment options are most effective in the acute thrombus, which is composed predominantly of a loose mesh of fibrin and red blood cells (RBCs), making current anticoagulation therapies and thrombolytics quite effective in treatment. Later stages of thrombus are more cellular containing leukocytes, and develop a fibrotic collagenous framework that is more resistant to our current treatments. Understanding the biology of an evolving thrombus will allow us to tailor our treatment and optimize outcomes, as well as focus on novel therapies for the treatment of chronic thrombus. Given the morbidity and mortality of both post thrombotic syndrome (PTS) in patients with deep VT, as well as chronic thromboembolic pulmonary hypertension (CTEPH) in patients with pulmonary embolism (PE), new and innovative therapies must continue to be explored to help prevent these potentially devastating conditions.

Evaluation of the duration of thromboembolic prophylaxis after high-risk orthopaedic surgery: The ETHOS observational study

Real-life data on post-discharge venous thromboembolism (VTE) prophylaxis practices and treatments are lacking. We assessed post-operative VTE prophylaxis prescribed and received in a prospective registry, compared with the 2004 American College of Chest Physicians (ACCP) guidelines in high-risk orthopaedic surgery patients. Consecutive patients undergoing total hip arthroplasty (THA), hip fracture surgery (HFS), or knee arthroplasty (KA) were enrolled at discharge from 161 centres in 17 European countries if they had received in-hospital VTE prophylaxis that was considered in accordance with the ACCP guidelines by the treating physician. Data on prescribed and actual prophylaxis were obtained from hospital charts and patient post-discharge diaries. Post-operative prophylaxis prescribed and actual prophylaxis received were considered adherent or adequate, respectively, if recommended therapies were used for ≥28 days (HFS and THA) or ≥10 days (KA). Among 4,388 patients, 69.9% were prescribed ACCP-adherent VTE prophylaxis (THA: 1,411/2,217 [63.6%]; HFS: 701/1,112 [63.0%]; KA: 955/1,059 [90.2%]). Actual prophylaxis received was described in 3,939 patients with an available diary after discharge (non-evaluability rate of 10%). Mean actual durations of pharmacological prophylaxis from surgery were: 28.4 ± 13.7 (THA), 29.3 ± 13.9 (HFS), and 28.7 ± 14.1 days (KA). ACCP-adequate VTE prophylaxis was received by 66.5% of patients (60.9% THA, 55.4% HFS, and 88.7% KA). Prophylaxis inadequacies were mainly due to inadequate prescription, non-recommended prophylaxis prescription at discharge, or too short prophylaxis prescribed. In high-risk orthopaedic surgery patients with hospital-initiated prophylaxis, there is a gap between ACCP recommendations, prescribed and actual prophylaxis received, mainly due to inadequate prescription at discharge.

Guidelines for Perioperative Care in Bariatric Surgery: Enhanced Recovery After Surgery (ERAS) Society Recommendations

BACKGROUND

During the last two decades, an increasing number of bariatric surgical procedures have been performed worldwide. There is no consensus regarding optimal perioperative care in bariatric surgery. This review aims to present such a consensus and to provide graded recommendations for elements in an evidence-based "enhanced" perioperative protocol.

METHODS

The English-language literature between January 1966 and January 2015 was searched, with particular attention paid to meta-analyses, randomised controlled trials and large prospective cohort studies. Selected studies were examined, reviewed and graded. After critical appraisal of these studies, the group of authors reached a consensus recommendation.

RESULTS

Although for some elements, recommendations are extrapolated from non-bariatric settings (mainly colorectal), most recommendations are based on good-quality trials or meta-analyses of good-quality trials.

CONCLUSIONS

A comprehensive evidence-based consensus was reached and is presented in this review by the enhanced recovery after surgery (ERAS) Society. The guidelines were endorsed by the International Association for Surgical Metabolism and Nutrition (IASMEN) and based on the evidence available in the literature for each of the elements of the multimodal perioperative care pathway for patients undergoing bariatric 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.

Low-Dose Warfarin for Prevention of Symptomatic Thromboembolism after Orthopedic Surgery

BACKGROUND:

Warfarin dosing with a target international normalized ratio (INR) range of 1.5–2.5 has not been reported as adequate for venous thromboembolism (VTE) prophylaxis after total knee (TKR) and total hip replacement (THR) surgery. OBJECTIVE: To evaluate the rate of symptomatic VTE after TKR and THR surgery using a low-dose (INR 1.5–2.5) warfarin protocol started the evening before surgery compared with a literature cohort treated with enoxaparin.

METHODS:

TKR/THR patients treated with a 21-day low-dose warfarin protocol were followed via a consecutive observational design. Main outcome measures were symptomatic VTE and pulmonary embolism (PE), with major bleeds and death as secondary outcomes. Low-dose warfarin was compared with a literature cohort of patients treated with enoxaparin who received enoxaparin for a similar length of time and was evaluated for the same outcomes. Cohort event rates were derived as a weighted average using the DerSimonian model.

RESULTS:

VTE, PE, bleeds, and deaths in the low-dose warfarin group were 8 (1.04%), 4 (0.52%), 8 (1.04%), and 4 (0.52%), respectively. The cohort weighted average values were 35 (1.33%), 19 (0.72%), 65 (2.46%), and 18 (0.67%), respectively. Odds ratios for low-dose warfarin for VTE, PE, and VTE plus PE were 0.778 (95% CI 0.36 to 1.68), 0.717 (0.24 to 2.11), and 0.754 (0.41 to 1.42), respectively, all nonsignificant. Odds ratios for bleeds and death were 0.420 (0.20 to 0.87; p = 0.02) and 0.756 (0.26 to 2.24; NS), respectively.

CONCLUSIONS:

For this evaluation, low-dose warfarin was comparable to the enoxaparin cohort for development of VTE, PE, and VTE+PE. Incidences of bleeds in the enoxaparin cohort were significantly higher than in patients receiving low-dose warfarin.

Choosing the Appropriate Antithrombotic Agent for the Prevention and Treatment of VTE: A Case-Based Approach

Objective:

To review the risk of venous thromboembolism (VTE) in various patient populations and evaluate the agents available for the prevention and treatment of VTE using a case-based approach.

Data Sources:

A MEDLINE search (1995–July 2006) was conducted to identify relevant literature. Additional references were reviewed from selected articles.

Study Selection and Data Extraction:

Articles related to the prevention of VTE in orthopedic surgery, general surgery, and medically ill patients, as well as the treatment of VTE, were reviewed.

Data Synthesis:

Pharmacologic options for the prevention and treatment of VTE include warfarin, unfractionated heparin (UFH), low-molecular-weight heparins (LMWH), and fondaparinux. Current guidelines support the use of warfarin, LMWH, or fondaparinux for VTE prophylaxis following lower limb major orthopedic surgery. For VTE prophylaxis in hospitalized medical patients or patients undergoing general surgery, use of UFH and LMWH is supported; however, recent data on fondaparinux suggest that it is also effective in these patient populations. The use of UFH or LMWH (both in conjunction with warfarin) for treatment of acute deep venous thrombosis or nonmassive pulmonary embolism is recommended. Recent data suggest that fondaparinux (in conjunction with warfarin) is also effective for the treatment of VTE. A variety of pharmacokinetic, pharmacodynamic, and pharmacoeconomic factors differentiate each agent for the various indications.

Conclusions:

Currently, a “one-size-fits-all” anticoagulant is not available for treatment of VTE. A variety of patient factors, including type of surgery, medical indication, thrombotic risk factors, bleeding risk, history of heparin-induced thrombocytopenia, and a variety of comorbid conditions can affect the safety, efficacy, and selection of appropriate VTE therapy.

Venous Thromboembolism After Knee Arthroscopy in Undiagnosed Familial Thrombophilia

Venous thromboembolism is uncommon after knee arthroscopy, and there are no guidelines for thromboprophylaxis in elective routine knee arthroscopy. Preoperative evaluation of common thrombophilias should provide guidance for postarthroscopy thromboprophylaxis in otherwise healthy patients who are at high risk for venous thromboembolism. This study assessed 10 patients with venous thromboembolism after total hip or knee arthroplasty. Patients were assessed if venous thromboembolism occurred within 6 months after knee arthroscopy (n=10) or total hip or knee arthroplasty (n=21). This study assessed gene mutations (factor V Leiden, prothrombin G20210A, plasminogen activator inhibitor, methylenetetrahydrofolate reductase) and serologic thrombophilias (high levels of factors VIII and XI, homocysteine, anticardiolipin immunoglobulin G and immunoglobulin M antibodies, and lupus anticoagulant; low antigenic protein C, S, and free S; and antithrombin III deficiency). The same coagulation data were obtained for normal subjects (n=110). The major thrombophilias in the arthroscopy group were factor V Leiden heterozygosity (40%), high factor VIII level (50%), and high homocysteine (30%). The respective values in control subjects were 2% (P=.0004), 7% (P=.0011), and 5% (P=.02). When the arthroscopy group was compared with the 21 patients who had venous thromboembolism after total hip or knee arthroplasty, the sole difference was factor V Leiden heterozygosity, which was 40% vs 0%, respectively (P=.007). Although venous thromboembolism after knee arthroscopy is uncommon, to identify high-risk patients and guide postoperative thromboprophylaxis, the authors suggest routine preoperative measurement of 3 common familial thrombophilias: factor V Leiden, factor VIII, and homocysteine. [Orthopedics. 2016; 39(6):e1052-e1057.].

Primary Joint Arthroplasty Surgery: Is the Risk of Major Bleeding Higher in Elderly Patients? A Retrospective Cohort Study

BACKGROUND

Increased risk of bleeding after major orthopedic surgery (MOS) has been widely documented in general population. However, this complication has not been studied in elderly patients. The purpose of this study is to determine whether the risk of major bleeding after MOS is higher in elderly patients, compared with those operated at a younger age.

METHODS

This retrospective cohort study included total hip and total knee arthroplasty patients operated during 5 consecutive years. The main outcome was the occurrence of major bleeding. Patients with other causes of bleeding were excluded. Relative risks (RRs) and confidence intervals (CIs) were calculated, and a multivariate analysis was performed.

RESULTS

A total of 1048 patients were included, 56% of patients were hip arthroplasties. At the time of surgery, 553 (53%) patients were older than 70 years. Patients aged >70 years showed an increased risk of major bleeding (RR: 2.42 [95% CI: 1.54-3.81]). For hip arthroplasty, the RR of bleeding was 2.61 (95%CI: 1.50-4.53) and 2.25 (95% CI: 1.03-4.94) for knee arthroplasty. After multivariate analysis, age was found to be independently associated with higher risk of major bleeding.

CONCLUSION

According to European Medicines Agency criteria, patients aged ≥70 years are at a higher risk of major bleeding after MOS, result of a higher frequency of blood transfusions in this group of patients. Standardized protocols for blood transfusion in these patients are still required.

Therapeutic Update on the Prevention and Treatment of Venous Thromboembolism

Venous thromboembolism (VTE) is a common condition that increases in incidence with age and risk factors. Therapies for VTE are aimed at either preventing the disease in high-risk individuals or treating patients who have developed VTE. Assessing risk and aggressively using the recommended therapies is primacy in preventing VTE in surgical and medical patients. Risk of VTE in medical patients has become more defined in recent years, and prophylaxis in this group can prevent scores of iatrogenic VTE. Treatment of VTE has evolved in the past decade from a condition that required hospitalization for 5 to 7 days to a disease state that can be conveniently and safely treated on an outpatient basis, largely due to the advent of low-molecular-weight heparins and patient self-directed treatment.

Low-molecular-weight heparin to prevent recurrent venous thromboembolism in pregnancy: Rationale and design of the Highlow study, a randomised trial of two doses

BACKGROUND

Women with a history of venous thromboembolism (VTE) have a 2% to 10% absolute risk of VTE recurrence during subsequent pregnancies. Therefore, current guidelines recommend that all pregnant women with a history of VTE receive pharmacologic thromboprophylaxis. The optimal dose of low-molecular-weight heparin (LMWH) for thromboprophylaxis is unknown. In the Highlow study (NCT 01828697; www.highlowstudy.org), we compare a fixed low dose of LMWH with an intermediate dose of LMWH for the prevention of pregnancy-associated recurrent VTE. We present the rationale and design features of this study.

METHODS

The Highlow study is an investigator-initiated, multicentre, international, open-label, randomised trial. Pregnant women with a history of VTE and an indication for ante- and postpartum pharmacologic thromboprophylaxis are included before 14weeks of gestation. The primary efficacy outcome is symptomatic recurrent VTE during pregnancy and 6weeks postpartum. The primary safety outcomes are clinically relevant bleeding, blood transfusions before 6weeks postpartum and mortality. Patients are closely monitored to detect cutaneous reactions to LMWH and are followed for 3months after delivery. A central independent adjudication committee adjudicates all suspected outcome events.

CONCLUSION

The Highlow study is the first large randomised controlled trial in pregnancy that will provide high-quality evidence on the optimal dose of LWMH thromboprophylaxis for the prevention of recurrent VTE in pregnant women with a history of VTE.

Venous thromboembolism prophylaxis in the massive weight loss patient: relative risk of bleeding

BACKGROUND

Measures that can reduce the incidence of venous thromboembolism (VTE) are of great clinical importance. In addition to the use of sequential compression devices (SCDs), chemoprophylaxis with low-molecular-weight heparin (LMWH) has been recommended by the American College of Chest Physicians for major general surgery procedures. There remains inconclusive evidence to support guidelines for the plastic surgery population, and some surgeons hesitate to use anticoagulation due to concerns about bleeding in broad planes of dissection. The purpose of this study was to evaluate the risk of postoperative complications secondary to chemical thromboprophylaxis in massive weight loss patients.

METHODS

Five hundred forty-six surgical cases were enrolled in an institutional review board-approved prospective clinical database in the 2 years before and after routine LMWH use was initiated. Inclusion required weight loss of greater than 50 lb. Group 1 had SCDs only (n = 334), whereas group 2 had SCDs and LMWH 6 hours postoperatively (n = 212). Risk of VTE was calculated and complications of LMWH administration were analyzed.

RESULTS

The overall risk of deep venous thrombosis and pulmonary embolism was 0.18%. There was no statistical difference between the groups (P > 0.05). Overall risk of hematoma was 5.4%, in concordance with the literature. There was no difference in hematoma risk between the groups (4.6% before and 6.6% after LMWH; P = 0.3). The transfusion rate was 8.5% before use of LMWH (group 1) and 7.6% after (group 2; P = 0.7).

CONCLUSIONS

Strategies to reduce VTE rates remain important in all areas of plastic surgery. We have demonstrated no increased risk of transfusion or hematoma and a low overall incidence of VTE after implementing a chemoprophylaxis regimen. Postoperative LMWH can provide an excellent balance between VTE prophylaxis and the risk of bleeding complications.

Venous thromboembolism: identifying patients at risk and establishing prophylaxis

Venous thromboembolism (VTE) is a major cause of morbidity and mortality and is associated with substantial healthcare costs. Identification of patients at risk of developing VTE enables appropriate thromboprophylaxis to be implemented. Although no predisposing risk factors can be identified in many patients in whom VTE develops, most have at least one underlying risk factor which can be categorized according to whether it confers low, moderate, or high risk. Clinical trials have demonstrated the effectiveness of thromboprophylaxis, both non-pharmacological and pharmacological, in a host of medical settings and there is sufficient evidence to support routine prophylaxis in many groups of patients. The implementation of decision making tools based on risk factor assessment improves the prescription of appropriate VTE prophylaxis. Nonetheless, thromboprophylaxis is often inadequate, with haphazard risk assessment and application of guidelines, leading to easily preventable instances of VTE. The most commonly used agents for pharmacological thromboprophylaxis of VTE are low dose unfractionated heparin; a low molecular weight heparin such as dalteparin, enoxaparin or tinzaparin; fondaparinux; warfarin; or aspirin. However, these have a number of drawbacks, principally the need for parenteral administration (with heparins) and frequent coagulation monitoring (with warfarin). The optimal anticoagulant would be orally administered, with a wide therapeutic window, rapid onset of action, predictable pharmacodynamics and pharmacokinetics, minimal interactions with food and other drugs, an ability to inhibit free and clot-bound coagulation factors, low, non-specific binding, and no requirement for routine coagulation monitoring or dose adjustment. A number of novel, single-target oral anticoagulants have been developed that appear to fulfill many of these requirements. This narrative review discusses the use of guidelines and risk assessment tools to identify patients at risk of VTE; it provides an overview of appropriate prophylaxis strategies in these patients with a summary of clinical trial results with novel oral anticoagulants.

Extended-Duration Venous Thromboembolism Prophylaxis in Hospitalized Acutely Ill Medical Patients

Objective: To evaluate the risks and benefits of extended-duration thromboprophylaxis (EDT) beyond hospitalization in acutely ill medical patients. Data Sources: PubMed was searched from inception (1946) through February 2015 for the search terms venous thrombosis/prevention and control, venous thromboembolism/prevention and control, anticoagulants, and aspirin. Study Selection and Data Extraction: Relevant clinical trials evaluating pharmacologic strategies for EDT were screened for inclusion. Bibliographies of articles were extensively reviewed for additional sources. Data Synthesis: Three studies, and one additional subgroup analysis, were identified for inclusion. Enoxaparin and rivaroxaban demonstrated a significant reduction in venous thromboembolism (VTE) with EDT, but the benefit with enoxaparin was limited to the highest risk groups and women. The improved efficacy in both studies was accompanied by a ~2.5-fold increase in risk of major hemorrhage. Apixaban was unable to demonstrate a reduction of VTE and was also associated with a significant increase in bleeding. Conclusions: EDT should not be routinely provided to all medically ill patients. It may be considered in patients at the highest risk for VTE, but careful consideration must be used due to the increased risk of bleeding.

Bridging therapy for oral anticoagulation increases the risk for bleeding-related complications in total joint arthroplasty

Background

Patients scheduled for elective surgery with a high risk of thromboembolism require anticoagulation bridging therapy perioperatively. The purpose of this study was to assess the risk of thromboembolic events and bleeding-related complications after total hip and knee arthroplasty in patients requiring bridging therapy for anticoagulants.

Methods

A retrospective cohort study of all patients with primary total hip or total knee replacement in a 4-year period was performed. Outcome measures were blood loss, thromboembolic and bleeding-related complications and hospital stay.

Results

Bridged patients had more blood loss and higher complication rates than the control group. Most complications were bleeding-related, and there were no thromboembolic events. Seven of the 14 (50 %) total hip patients bridged with unfractioned heparin required reoperation (three patients with ischial neuropraxia due to hematoma). There were two bleeding-related deaths in total hip patients bridged with low-molecular-weight heparin. Mean hospital stay was significantly longer in unfractioned heparin bridging.

Conclusion

In this study, there was a significant increase in bleeding-related complications in total joint replacement with bridging therapy compared to prophylaxis. This risk was highest in patients with total hip arthroplasty. There were no thromboembolic events in bridged patients.