Low-molecular-weight heparin (enoxaparin) as prophylaxis against venous thromboembolism after total hip replacement

Analysis of Deep Vein Thrombosis: A Prospective Observational Study

Objective This prospective observational study aimed to investigate the prevalence, acquired risk factors, and treatment outcomes of deep vein thrombosis (DVT) at a tertiary care center in India. Materials and methods Conducted from 2022 to 2024, the study included 100 patients diagnosed with lower extremity DVT. The study subjects included patients visiting the general surgery, vascular surgery, surgical gastroenterology, general medicine, emergency medicine, and obstetrics and gynecology departments with symptoms suggestive of DVT. The primary objectives were to evaluate the effectiveness of conventional anticoagulation and thrombolytic therapy as well as to assess the various acquired risk factors for DVT. Patients underwent comprehensive clinical and biochemical evaluations, including venous Doppler ultrasound, and were treated based on their clinical presentations. The study's primary end outcome was early recanalization rates on day 14 post-initiation of treatment and occurrence of post-thrombotic syndrome (PTS). Secondary outcome measures included duration of hospital stay, time taken to return to work and early complications. Results The highest incidence of DVT was in individuals in their forties, with a mean age of 44.84+/-11.71 years and a female preponderance of 58% (n=58). Key acquired risk factors identified included hypertension (25%; n=25), diabetes mellitus (20%; n=20), obesity (16%; n=16), and smoking (34%; n=34). Obesity (16%; n=16), a history of DVT (25%; n=25), trauma/immobilization (9%; n=9), pregnancy (10%; n=10), smoking (34%; n=34), and cancer (20%; n=20) were also identified as important acquired risk factors contributing to the occurrence of DVT. Amongst the study participants, 28% (n=28) had femoro-popliteal segment involvement, 36% (n=36) had calf vein thrombosis, and the remaining 36% (n=36) showed femoro-iliac segment thrombosis. Conventional anticoagulation was administered to 69% (n=69) of patients, while 31% (n=31) received thrombolytic therapy. Both treatments showed similar recanalization rates, but thrombolytic therapy was associated with a longer hospital stay (8.61+/-1.65 days; p=0.024; p<0.05) and return to work period (14.65+/-2.31 days; p=0.012; p<0.05). Post-thrombotic syndrome was less common in the thrombolytic therapy group (3%; n=3). Three patients died in the study, with the cause being pulmonary embolism. The descriptive statistics were computed to delineate the study sample. After completion of data collection, data analysis was achieved using SPSS for Windows, Version 16 (Released 2007; SPSS Inc., Chicago, United States), and the correlations sought after were achieved using the chi-square test of significance. Conclusion The study underscores the importance of recognizing and managing acquired risk factors for DVT, thereby facilitating early diagnosis and ultimately reducing morbidity and mortality. Understanding these factors and employing effective treatment strategies are crucial for better management and prevention of DVT, enhancing patient outcomes.

American Association for the Surgery of Trauma/American College of Surgeons Committee on Trauma clinical protocol for postdischarge venous thromboembolism prophylaxis after trauma

ABSTRACT

Trauma patients are at an elevated risk for developing venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis. In the inpatient setting, prompt pharmacologic prophylaxis is utilized to prevent VTE. For patients with lower extremity fractures or limited mobility, VTE risk does not return to baseline levels postdischarge. Currently, there are limited data to guide postdischarge VTE prophylaxis in trauma patients. The goal of these postdischarge VTE prophylaxis guidelines are to identify patients at the highest risk of developing VTE after discharge and to offer pharmacologic prophylaxis strategies to limit this risk.

Update on the Pharmacological Actions of Enoxaparin in Nonsurgical Patients

Low-molecular-weight heparins are a class of drugs derived from the enzymatic depolymerization of unfractionated heparin that includes enoxaparin. Several studies have been performed on enoxaparin in recent years, in particular for the prevention and treatment of venous thromboembolism and for the treatment of acute coronary syndrome. Furthermore, the use of enoxaparin has been extended to other clinical situations that require antithrombotic pharmacological prevention, such as hemodialysis and recurrent abortion. In this review, we report the main clinical experiences of using enoxaparin in the prevention of VTE in nonsurgical patients.

Venous Thromboembolism Chemoprophylaxis Adherence Rates After Major Cancer Surgery

Importance

Venous thromboembolism (VTE) represents a major source of preventable morbidity and mortality and is a leading cause of death in the US after cancer surgery. Previous research demonstrated variability in VTE chemoprophylaxis prescribing, although it is unknown how these rates compare with performance in the Veterans Health Administration (VHA).

Objective

To determine VTE rates after cancer surgery, as well as rates of inpatient and outpatient (posthospital discharge) chemoprophylaxis adherence within the VHA.

Design, Setting, and Participants

This retrospective cohort study within 101 hospitals of the VHA health system included patients aged 41 years or older without preexisting bleeding disorders or anticoagulation usage who underwent surgical treatment for cancer with general surgery, thoracic surgery, or urology between January 1, 2015, and December 31, 2022. The VHA Corporate Data Warehouse, Pharmacy Benefits Management database, and the Veterans Affairs Surgical Quality Improvement Program database were used to identify eligible patients. Data analysis was conducted between January 2022 and July 2023.

Exposures

Inpatient surgery for cancer with general surgery, thoracic surgery, or urology.

Main Outcomes and Measures

Rates of postoperative VTE events within 30 days of surgery and VTE chemoprophylaxis adherence were determined. Multivariable Poisson regression was used to determine incidence-rate ratios of inpatient and postdischarge chemoprophylaxis adherence by surgical specialty.

Results

Overall, 30 039 veterans (median [IQR] age, 67 [62-71] years; 29 386 men [97.8%]; 7771 African American or Black patients [25.9%]) who underwent surgery for cancer and were at highest risk for VTE were included. The overall postoperative VTE rate was 1.3% (385 patients) with 199 patients (0.7%) receiving a diagnosis during inpatient hospitalization and 186 patients (0.6%) receiving a diagnosis postdischarge. Inpatient chemoprophylaxis was ordered for 24 139 patients (80.4%). Inpatient chemoprophylaxis ordering rates were highest for patients who underwent procedures with general surgery (10 102 of 10 301 patients [98.1%]) and lowest for patients who underwent procedures with urology (11 471 of 17 089 patients [67.1%]). Overall, 3142 patients (10.5%) received postdischarge chemoprophylaxis, with notable variation by specialty.

Conclusions and Relevance

These findings indicate the overall VTE rate after cancer surgery within the VHA is low, VHA inpatient chemoprophylaxis rates are high, and postdischarge VTE chemoprophylaxis prescribing is similar to that of non-VHA health systems. Specialty and procedure variation exists for chemoprophylaxis and may be justified given the low risks of overall and postdischarge VTE.

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.

Approaches for optimizing venous thromboembolism prevention in injured patients: Findings from the consensus conference to implement optimal venous thromboembolism prophylaxis in trauma

ABSTRACT

Venous thromboembolism (VTE) is a major issue in trauma patients. Without prophylaxis, the rate of deep venous thrombosis approaches 60% and even with chemoprophylaxis may be nearly 30%. Advances in VTE reduction are imperative to reduce the burden of this issue in the trauma population. Novel approaches in VTE prevention may include new medications, dosing regimens, and extending prophylaxis to the postdischarge phase of care. Standard dosing regimens of low-molecular-weight heparin are insufficient in trauma, shifting our focus toward alternative dosing strategies to improve prophylaxis. Mixed data suggest that anti-Xa-guided dosage, weight-based dosing, and thromboelastography are among these potential strategies. The concern for VTE in trauma does not end upon discharge, however. The risk for VTE in this population extends well beyond hospitalization. Variable extended thromboprophylaxis regimens using aspirin, low-molecular-weight heparin, and direct oral anticoagulants have been suggested to mitigate this prolonged VTE risk, but the ideal approach for outpatient VTE prevention is still unclear. As part of the 2022 Consensus Conference to Implement Optimal Venous Thromboembolism Prophylaxis in Trauma, a multidisciplinary array of participants, including physicians from multiple specialties, pharmacists, nurses, advanced practice providers, and patients met to attack these issues. This paper aims to review the current literature on novel approaches for optimizing VTE prevention in injured patients and identify research gaps that should be investigated to improve VTE rates in trauma.

Preoperative coagulation biomarkers associate with survival and pulmonary embolism after surgical treatment of non-spinal skeletal metastases

BACKGROUND

Thrombotic complications are synergistic and associated with orthopedic procedures, trauma, and malignancy. Because cancer enhances coagulation activity and vice versa, we assessed preoperative biomarkers for survival and complications after treatment of pathologic fractures in non-spinal skeletal metastases.

PATIENTS/METHODS

Our study population comprised 113 actual or impending pathologic fractures in 100 patients admitted to two referral centers. Laboratory variables were collected retrospectively from patient records and analyzed related to incidence of pulmonary embolism (PE) and mortality (Kaplan-Meier and Cox regression analyses and biomarker quartiles).

RESULTS

Preoperative coagulation variables were high without exceptions. PE occurred in 12 patients at 36 post-operative days at incidence of 11% in the lower and 13% in the upper extremity fractures. Patients with fibrinogen exceeding 5 g/l (log-rank 0.022) developed PE earlier (5 to 15 days postoperatively) than others. Also, mean patient survival with normal fibrinogen range (2-4 g/l) was 34 months, whereas it halved upon elevated fibrinogen (log-rank p = 0.009). Survival in patients with FVIII levels under 326 IU/dl (Q3) was 22 months, but only 7 months if FVIII exceeded 326 IU/dl (log-rank p = 0.002). Combined elevated fibrinogen and FVIII predicted survival: for patients with levels below threshold limits was 22 months versus only 7 months when both variables exceeded the ranges (log-rank p < 0.001). Multivariate analysis to control confounders supported an independent role of fibrinogen and FVIII for survival.

CONCLUSIONS

Our study has established fibrinogen and FVIII as potential preoperative contributors of survival and complications after treatment of metastatic fractures. These results highlight the need for novel anticoagulation and thromboprophylaxis strategies among these patients.

Prophylaxis for Venous Thromboembolic Events in Elective Total Hip and Total Knee Arthroplasty

Venous thromboembolism (VTE) is a serious complication after major orthopaedic operations, such as a total hip (THA) and knee (TKA) arthroplasty. Therefore, perioperative VTE prophylaxis is recommended; a multitude of modern options are available, including both pharmacologic (aspirin, unfractionated and lowmolecular-weight heparin, vitamin K antagonists, and novel oral anticoagulants) and/or mechanical interventions (early mobilization, graduated compression stockings, intermittent pneumatic compression devices, and venous foot pumps). However, because of the abundance of these possibilities, it is crucial to understand the benefits and drawbacks of each VTE prophylaxis option to ensure that the optimal treatment plan is developed for each patient. The American College of Chest Physicians (AACP) and the American Academy of Orthopaedic Surgeons (AAOS) have both published individual guidelines on VTE prophylaxis regimens, alongside numerous studies evaluating the efficacy and outcomes of the different prophylaxis modalities. The purpose of this review is to provide a summary of the evidence on VTE prophylaxis after elective total hip and knee arthroplasty based on current guidelines and highlight the major concerns and potential complications.

Glucocorticoid-induced osteonecrosis in systemic lupus erythematosus patients

Osteonecrosis (ON) is a complex and multifactorial complication of systemic lupus erythematosus (SLE). ON is a devastating condition that causes severe pain and compromises the quality of life. The prevalence of ON in SLE patients is variable, ranging from 1.7% to 52%. However, the pathophysiology and risk factors for ON in patients with SLE have not yet been fully determined. Several mechanisms for SLE patients' propensity to develop ON have been proposed. Glucocorticoid is a widely used therapeutic option for SLE patients and high-dose glucocorticoid therapy in SLE patients is strongly associated with the development of ON. Although the hips and knees are the most commonly affected areas, it may be present at multiple anatomical locations. Clinically, ON often remains undetected until patients feel discomfort and pain at specific sites at which point the process of bone death is already advanced. However, strategies for prevention and options for treatment are limited. Here, we review the epidemiology, risk factors, diagnosis, and treatment options for glucocorticoid-induced ON, with a specific focus on patients with SLE.

Optimal Dosing of Prophylactic Enoxaparin after Surgical Procedures: Results of the Double-Blind, Randomized, Controlled FIxed or Variable Enoxaparin (FIVE) Trial

BACKGROUND

The accepted "one-size-fits-all" dose strategy for prophylactic enoxaparin may not optimize the medication's risks and benefits after surgical procedures. The authors hypothesized that weight-based administration might improve the pharmacokinetics of prophylactic enoxaparin when compared to fixed-dose administration.

METHODS

The FIxed or Variable Enoxaparin (FIVE) trial was a randomized, double-blind trial that compared the pharmacokinetic and clinical outcomes of patients assigned randomly to postoperative venous thromboembolism prophylaxis using enoxaparin 40 mg twice daily or enoxaparin 0.5 mg/kg twice daily. Patients were randomized after surgery and received the first enoxaparin dose at 8 hours after surgery. Primary hypotheses were (1) weight-based administration is noninferior to a fixed dose for avoiding underanticoagulation (anti-factor Xa <0.2 IU/ml) and (2) weight-based administration is superior to fixed-dose administration for avoiding overanticoagulation (anti-factor Xa >0.4 IU/ml). Secondary endpoints were 90-day venous thromboembolism and bleeding.

RESULTS

In total, 295 patients were randomized, with 151 assigned to fixed-dose and 144 to weight-based administration of enoxaparin. For avoidance of under anticoagulation, weight-based administration had a greater effectiveness (79.9 percent versus 76.6 percent); the 3.3 percent (95 percent CI, -7.5 to 12.5 percent) greater effectiveness achieved statistically significant noninferiority relative to the a priori specified -12 percent noninferiority margin (p = 0.004). For avoidance of overanticoagulation, weight-based enoxaparin administration was superior to fixed-dose administration (90.6 percent versus 82.2 percent); the 8.4 percent (95 percent CI, 0.1 to 16.6 percent) greater effectiveness showed significant safety superiority (p = 0.046). Ninety-day venous thromboembolism and major bleeding were not different between fixed-dose and weight-based cohorts (0.66 percent versus 0.69 percent, p = 0.98; 3.3 percent versus 4.2 percent, p = 0.72, respectively).

CONCLUSION

Weight-based administration showed superior pharmacokinetics for avoidance of underanticoagulation and overanticoagulation in postoperative patients receiving prophylactic enoxaparin.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

Fatal retroperitoneal hematoma associated with Covid-19 prophylactic anticoagulation protocol

Due to the association between Covid-19 and thromboembolic events, there has been a surge in anticoagulation use during the pandemic based on evolving guidelines for management of hospitalized Covid-19 patients. Spontaneous soft tissue hematoma can be a severe complication of anticoagulation. Herein we present a fatal case of severe spontaneous soft tissue hematoma secondary to anticoagulant therapy in a 67kg 81-year-old female with chronic kidney disease who was admitted to the hospital with Covid-19 pneumonia. There is currently no evidence of mortality benefit among Covid-19 patients on high-dose anticoagulation. In the future we hope that practitioners will consider the bleeding risks of anticoagulation and consider patients’ age, weight and renal function when determining prophylactic anticoagulation regimens in Covid-19 patients.

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.

Double Blind Pilot Randomized Trial Comparing Extended Anticoagulation to Placebo Following Major Lung Resection for Cancer

Venous thromboembolism (VTE), which comprises pulmonary embolus (PE) and deep vein thrombosis (DVT), is a significant cause of postoperative morbidity and mortality. This pilot randomized control trial (RCT) evaluated the feasibility of a full-scale RCT investigating extended thromboprophylaxis in patients undergoing oncological lung resections. Patients undergoing oncological lung resections in 2 tertiary centers received in-hospital, thromboprophylaxis and were randomized to receive post-discharge low-molecular-weight heparin (LMWH) or placebo injections once-daily for 30 days. At 30 days postoperatively, all patients underwent chest computed tomography with PE protocol and bilateral leg venous ultrasound. Primary outcomes included feasibility and safety; VTE incidence and 90-day survival were secondary outcomes. Between December 2015 and June 2018, 619 patients were screened, of whom 62.7% (165/263) of eligible patients consented to participate, and 133 (81%) were randomized. One-hundred and 3 patients, (77.4%), completed the 90-day study follow-up. Reasons for non-participation pre-randomization included patient discomfort and LMWH/placebo administration challenges. Post-randomization withdrawals were due to patient preference, surgeon preference and minor adverse events. Six asymptomatic VTE events (5 PE and 1 DVT) were detected within 30 days (3 in each group), for an overall incidence of 7%. There were 3 minor and no major adverse events. This study is the first to demonstrate the feasibility and safety of a full-scale extended thromboprophylaxis RCT in thoracic surgical oncology. Our results demonstrate that, while recruitment and retention rates were modest, the study design is feasible and with minimal adverse events and no intervention-related mortality.

Thromboprophylaxis across orthopaedic surgery: Bibliometric analysis of the most cited articles

PURPOSE

One of the most common adverse events after orthopaedic surgery, with a potential for subsequent serious morbidity and mortality is venous thromboembolism (VTE). Bibliometric analysis has been performed regarding many topics and across orthopaedics. As DVT prophylaxis is a major component of both orthopaedic surgery considerations and research, a bibliometric analysis in this area would prove beneficial in not only in understanding the research done in the field thus far, but would also direct future research efforts.

METHODS

The Web of Science (WoS) database from the Institute of Scientific Information (ISI) was used to compile articles for bibliometric analysis using Boolean search: ((Orthopaedic∗ OR Orthopaedic∗) AND (thromboprophylaxis OR Thromboembolism OR Deep vein thrombosis OR thrombus OR embolism OR anticoagulation OR Embolus OR prophylaxis)).

RESULTS

The Top 100 cited articles included in the final list generated a total of 21,099 citations. The highest cited article was Prevention of venous thromboembolism by Geerts et al. published in Chest, which had a total of 2802 on WoS, and a calculated citation density of 215.54 of citations/years since publication. Comparing the overall citation against the year of publication there was a slight positive trend favoring more recent publications (R-value: 0.142; adjusted R-squared: 0.01; p = 0.16). Analysis of an articles Level of Evidence (LOE), 17 were grade with a level of I.

CONCLUSIONS

Orthopaedic thromboprophylaxis is an ever-changing field that is at the forefront of orthopaedic literature. The significant trend favoring high quality research within orthopaedic thromboprophylaxis demonstrates the importance of this topic and there was a need for a guide to best understand the evolution of DVT prophylaxis.

Bleeding complications of thromboprophylaxis with dabigatran, nadroparin or rivaroxaban for 6 weeks after total knee arthroplasty surgery: a randomised pilot study

OBJECTIVES

For the non-vitamin-K oral anticoagulants, data on bleeding when used for 42 days as thromboprophylaxis after total knee arthroplasty (TKA) are scarce. This pilot study assessed feasibility of a multicentre randomised clinical trial to evaluate major and clinically relevant non-major bleeding during 42-day use of dabigatran, nadroparin and rivaroxaban after TKA.

PATIENTS AND METHODS

In 70 weeks, between July 2012 and November 2013, 198 TKA patients were screened for eligibility in the Martini Hospital (Groningen, the Netherlands). Patients were randomly assigned to dabigatran (n=45), nadroparin (n=45) or rivaroxaban (n=48). The primary outcome was the combined endpoint of major bleeding and clinically relevant non-major bleeding. Secondary endpoints of this study were the occurrence of clinical venous thromboembolism (VTE) (pulmonary embolism or deep venous thrombosis), compliance, duration of hospital stay, rehospitalisation, adverse events and Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

The primary outcome was observed in 33.3% (95% CI 20.0% to 49.0%), 24.4% (95% CI 12.9% to 39.5%) and 27.1% (95% CI 15.3% to 41.8%) of patients who received dabigatran, nadroparin or rivaroxaban, respectively (p=0.67). Major bleeding was found in two patients who received nadroparin (p=0.21). Clinically relevant non-major bleeding was observed in 33.3% (95% CI 20.0% to 49.0%), 22.2% (95% CI 11.2% to 37.1%) and 27.1% (95% CI 15.3% to 41.8%) for dabigatran, nadroparin and rivaroxaban, respectively (p=0.51). Wound haematoma was the most observed bleeding event. VTE was found in one patient who received dabigatran (p=0.65). The presurgery and postsurgery KOOS qQuestionnaires were available for 32 (71%), 35 (77%) and 35 (73%) patients for dabigatran, nadroparin and rivaroxaban, respectively. KOOS was highly variable, and no significant difference between treatment groups in mean improvement was observed.

CONCLUSIONS

A multicentre clinical trial may be feasible. However, investments will be substantial. No differences in major and clinically relevant non-major bleeding events were found between dabigatran, nadroparin and rivaroxaban during 42 days after TKA. KOOS may not be suitable to detect functional loss due to bleeding.

TRIAL REGISTRATION NUMBER

NCT01431456.

A Prospective Cohort Comparative Study of Rivaroxaban, Dabigatran, and Apixaban Oral Thromboprophylaxis in 2431 Hip and Knee Arthroplasty Patients: Primary Efficacy Outcomes and Safety Profile

BACKGROUND

Direct oral anticoagulants (DOACs) have promised superior efficacy to low molecular weight heparins in the prevention of venous thromboembolism (VTE) in total hip and knee arthroplasty. However, there are concerns about raised associated bleeding and wound problems with these agents. This study aims to evaluate and compare the efficacy and safety of the 3 DOAC drugs: rivaroxaban, dabigatran and apixaban.

METHODS

The primary outcome measures were rate of symptomatic VTE and major bleeding. Secondary outcome measures were wound healing problems and requirement for return to theater. A total of 2431 patients received one of the DOAC drugs as thromboprophylaxis following total hip arthroplasty (35 days) or total knee arthroplasty (14 days) between 2011 and 2015. Binary variables were compared between the 3 groups by using the chi-squared test or Fisher's exact test. Relative risks of selected primary and secondary end points were also calculated for the prespecified pairwise comparison.

RESULTS

The overall symptomatic VTE rate was 2%. Rivaroxaban had a statistically significant superior efficacy for overall VTE prevention (0.8% vs 2.6%) compared with dabigatran (P < .01) and apixaban (P < .01), and deep vein thrombosis prevention (0.3% vs 2.2%) over dabigatran (P < .01). The overall rate of major bleeding was 1.2% with no significant difference observed between the 3 studied drugs.

CONCLUSION

All 3 drugs had symptomatic VTE rates comparable with low molecular weight heparin from the published literature. Rivaroxaban appears to have superior efficacy in VTE prevention over apixaban and dabigatran. No statistical difference was observed for major bleeding with any of the 3 agents.

The Use of Standard Cemented Femoral Stems in Total Hip Replacement After Failed Internal Fixation of Intertrochanteric Femoral Fractures

BACKGROUND

Total hip replacement (THR) after failed internal fixation of intertrochanteric femoral fractures is challenging. The aim of this study is to show the reliability of using standard cemented femoral stems in this operation.

METHODS

This work included 107 THRs performed in 107 patients after failed treatment of intertrochanteric femoral fractures. The etiology of failure included 67 cases of failure of fixation, 16 cases of nonunion, 15 cases of avascular necrosis, and 9 cases of post-traumatic osteoarthritis. There were 48 males and 59 females. The mean age was 66 years (range 58-81). Failed dynamic hip screws were removed at the time of THR, and the screw holes were blocked with cement. All cases had cemented standard stem femoral prostheses.

RESULTS

At an average 7.4 years with a minimum of 5 years of follow-up, 102 cases had good clinical and radiological outcomes and 5 cases had fair outcomes. One patient was infected and required 2 stages of revision arthroplasty. Two cases had intraoperative proximal femoral crack, and were treated by cerclage wires. Two patients had early postoperative dislocations. No patients had late periprosthetic femoral fractures or implant loosening.

CONCLUSION

Standard cemented femoral stems are reliable and cost-effective prostheses in such cases. It is not necessary to bypass the distal screw hole by doubling the femoral canal diameter as long as the bone holes are covered by cement.

Mortality risk associated with venous thromboembolism: a systematic review and Bayesian meta-analysis

BACKGROUND

Venous thromboembolism is associated with increased mortality risk in some populations, but how frequently it is a direct cause of death is unclear. We used data from venous thromboembolism prevention trials to evaluate the causal effect of venous thromboembolism reduction on mortality.

METHODS

We did a systematic review and meta-analysis of randomised controlled trials (RCTs) evaluating venous thromboembolism prevention. We searched MEDLINE, Embase, PubMed, and Web of Science starting from Jan 1, 1993, to March 19, 2018. We included studies of patients who were at elevated risk of venous thromboembolism and were randomly assigned to either anticoagulant or antiplatelet therapy versus placebo or no treatment. We excluded studies with an active control agent (which might mitigate the lethality of venous thromboembolism) and those for which mortality data were unavailable. We modelled heterogeneity in a Bayesian framework, taking overall mortality as a primary endpoint, and pulmonary embolism, fatal pulmonary embolism, and major bleeding as secondary endpoints. We focused our analyses on studies reporting statistically significant effects of prevention on venous thromboembolism endpoints. We report treatment effects as median risk ratios (RRs), wherein a null effect equals 1, with 95% credible intervals (CrIs). This meta-analysis was registered with PROSPERO, CRD42018089697.

FINDINGS

From 4229 studies screened, we identified 86 eligible RCTs; 52, with data from over 70 000 patients, were positive, with significantly increased venous thromboembolism risk in patients in control groups versus treatment groups (RR 2·74, 95% CrI 2·32-3·31, p<0·0001). The meta-analysis established that the causal effect of venous thromboembolism prevention on mortality was null (control group mortality was 3391 [9·8%] of 34 537 patients; treatment group mortality was 3498 [9·8%] of 35 795 patients [RR 1·01, 95% CrI 0·97-1·06; p=0·58]) with low heterogeneity (τ 0·02, 95% CrI 0·00-0·07, p=0·89). Patients in control groups had more pulmonary embolism (RR 2·22, 95% CrI 1·78-2·89, p<0·0001) and fatal pulmonary embolism (1·58, 1·14-2·19, p=0·01), but less major bleeding (0·60, 0·47-0·75, p<0·0001) than those in treatment groups. A meta-analysis with the additional 34 negative studies yielded similar results for all endpoints except fatal pulmonary embolism, where evidence of an effect was weaker (1·42, 1·05-1·91, p=0·02).

INTERPRETATION

The perception that venous thromboembolism is a common cause of mortality should be revised considering the null effect of venous thromboembolism prevention on mortality. Our findings call into question the use of composite endpoints in venous thromboembolism-prevention trials and provide rationale for de-escalation trials.

FUNDING

None.

Antithrombotic prophylaxis for surgery-associated venous thromboembolism risk in patients with inherited platelet disorders. The SPATA-DVT Study

Major surgery is associated with an increased risk of venous thromboembolism (VTE), thus the application of mechanical or pharmacologic prophylaxis is recommended. The incidence of VTE in patients with inherited platelet disorders (IPD) undergoing surgical procedures is unknown and no information on the current use and safety of thromboprophylaxis, particularly of low-molecular-weight-heparin in these patients is available. Here we explored the approach to thromboprophylaxis and thrombotic outcomes in IPD patients undergoing surgery at VTE-risk participating in the multicenter SPATA study. We evaluated 210 surgical procedures carried out in 155 patients with well-defined forms of IPD (VTE-risk: 31% high, 28.6% intermediate, 25.2% low, 15.2% very low). The use of thromboprophylaxis was low (23.3% of procedures), with higher prevalence in orthopedic and gynecological surgeries, and was related to VTE-risk. The most frequently employed thromboprophylaxis was mechanical and appeared to be effective, as no patients developed thrombosis, including patients belonging to the highest VTE-risk classes. Low-molecular-weight-heparin use was low (10.5%) and it did not influence the incidence of post-surgical bleeding or of antihemorrhagic prohemostatic interventions use. Two thromboembolic events were registered, both occurring after high VTE-risk procedures in patients who did not receive thromboprophylaxis (4.7%). Our findings suggest that VTE incidence is low in patients with IPD undergoing surgery at VTE-risk and that it is predicted by the Caprini score. Mechanical thromboprophylaxis may be of benefit in patients with IPD undergoing invasive procedures at VTE-risk and low-molecular-weight-heparin should be considered for major surgery.

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.

Reduction of Blood Loss by Tranexamic Acid Following Total Hip and Knee Arthroplasty: A Meta-Analysis

BACKGROUND

This study involved a meta-analysis of 36 published studies to examine the efficacy of intravenous (IV) and intra-articular (IA) tranexamic acid (TXA) in reducing blood loss, drain output, thromboembolic complications, and hospital stay following total hip and total knee arthroplasty. This study also evaluated whether treatment with a combination of both IA and IV TXA has an effect on these outcomes. Lastly, this study attempted to analyze the method and technique of TXA administration in order to establish a best practice for its use in reducing overall blood loss in arthroplasty procedures.

METHODS

MEDLINE, Embase, and the Cochrane Library database were screened. Studies comparing IV TXA with IA TXA or with combined IV and IA TXA were included. Data including total blood loss, drain output, thromboembolic complications, and hospital stay, where available, were analyzed using meta-analysis with fixed effects. Results are presented as the standardized mean difference (SMD), and meta-regression was employed to explore plausible demographic contributions to heterogeneity.

RESULTS

Twenty-eight randomized controlled trials, 3 prospective cohort studies, and 5 retrospective cohort studies with 5,499 patients were included in this review. IA administration during total knee arthroplasty showed a significant advantage in terms of total blood loss (SMD = -0.14, 95% confidence interval [CI] = -0.027 to -0.02, I = 78.2%) and drain output (SMD = -0.30, 95% CI = -0.43 to -0.18). There was no significant difference between IV and IA administration in total hip arthroplasty. Combined IA plus IV TXA was associated with a significant reduction in blood loss versus IV TXA alone in both total knee arthroplasty and total hip arthroplasty. IV TXA dosing varied, as 14 (39%) of the studies used a weight-based approach while 22 (61%) used a standard dose. Twenty-seven (96%) of 28 studies of IA administration used standard dosing while 1 study followed a weight-based protocol. There was no difference in symptomatic thromboembolic complications, with overall rates in total knee arthroplasty and total hip arthroplasty of 1.0% and 1.0% for IV administration and 1.1% and 0.3% for IA administration, respectively. There was no difference in length of hospital stay for IV versus IA TXA administration.

CONCLUSIONS

IA TXA, either alone or in conjunction with IV TXA, reduces total blood loss and/or drain output in total knee arthroplasty and total hip arthroplasty. Optimal methodology remains to be clarified; however, there are substantial economic benefits of utilizing either IV or IA TXA, with greater cost benefits when using IA TXA.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Venous Thromboembolism Prophylaxis Strategies for People Undergoing Elective Total Hip Replacement: A Systematic Review and Network Meta-Analysis

OBJECTIVES

To assess the efficacy and safety of venous thromboembolism prophylaxis in people undergoing elective total hip replacement.

METHODS

Systematic review and Bayesian network meta-analyses of randomized controlled trials were conducted for 3 outcomes: deep vein thrombosis (DVT), pulmonary embolism (PE), and major bleeding (MB). MEDLINE, EMBASE, and Cochrane Library (CENTRAL) databases were searched. Study quality was assessed using the Cochrane risk-of-bias checklist. Fixed- and random-effects models were fitted and compared. The median relative risk (RR) and odds ratio (OR) compared with no prophylaxis, with their 95% credible intervals (CrIs), rank, and probability of being the best, were calculated.

RESULTS

Forty-two (n = 24 374, 26 interventions), 30 (n = 28 842, 23 interventions), and 24 (n = 31 792, 15 interventions) randomized controlled trials were included in the DVT, PE, and MB networks, respectively. Rivaroxaban had the highest probability of being the most effective intervention for DVT (RR 0.06 [95% CrI 0.01-0.29]). Strategy of low-molecular-weight heparin followed by aspirin had the highest probability of reducing the risk of PE and MB (RR 0.0011 [95% CrI 0.00-0.096] and OR 0.37 [95% CrI 0.00-26.96], respectively). The ranking of efficacy estimates across the 3 networks, particularly PE and MB, had very wide CrIs, indicating high degree of uncertainty.

CONCLUSIONS

A strategy of low-molecular-weight heparin given for 10 days followed by aspirin for 28 days had the best benefit-risk balance, with the highest probability of being the best on the basis of the results of the PE and MB network meta-analyses. Nevertheless, there is considerable uncertainty around the median ranks of the interventions.

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.

The case for extended thromboprophylaxis in medically hospitalised patients – not yet made

Background

The role of extended thromboprophylaxis is established for surgical patients, but not yet for hospitalised medical patients.

Design

This systematic review and meta-analysis sought to explore the role of extended thromboprophylaxis for medically ill hospitalised patients.

Methods

Medline, EMBASE and Cochrane Libraries were searched and five randomised controlled trials were identified, comprising 20,046 extended and 20,078 standard duration thromboprophylaxis patients.

Results

Allocation to extended treatment, compared with standard duration therapy, significantly reduced the risk of symptomatic deep vein thrombosis (relative risk (RR) 0.47, 95% confidence interval (CI) 0.29–0.78, P = 0.003) and non-fatal pulmonary embolism (RR 0.59, 95% CI 0.39–0.91, P = 0.02). The risk of venous thromboembolism-related death was comparable between the extended and standard duration treatment groups (RR 0.81, 95% CI 0.6–1.09, P = 0.16). Extended treatment also doubled the risk of major bleeding (RR 2.04, 95% CI 1.42–2.91, P &lt; 0.001), without significantly affecting the risk of intracranial bleeding or bleeding-associated death. The cost of preventing one symptomatic deep vein thrombosis and non-fatal pulmonary embolism was found to be £24,972 (€27,969) and £45,148 (€50,566), respectively, which outweigh the direct cost of managing established venous thromboembolism as previously reported.

Conclusions

Extended duration thromboprophylaxis caused a reduction in the risk of venous thromboembolic events, but also a numerically comparable increase in major bleeding. Further trials are required in high-risk subpopulations who may derive mortality benefits from treatment. Only then could a change in current policy and practice be supported.

A prospective randomized comparative study to determine appropriate edoxaban administration period, to prevent deep vein thromboembolism in patients with total knee arthroplasty

BACKGROUND

This study aimed to determine the appropriate administration duration of edoxaban 15 mg (a factor Xa inhibitor) for the prevention of deep vein thrombosis (DVT) after total knee arthroplasty (TKA).

METHODS

Our study comprised 202 patients who underwent TKA (excluding bilateral TKA) at our institution between 2014 and 2015. The subjects received edoxaban 15 mg daily for 1 (n = 93) or 2 (n = 109) weeks; group assignment was random. B-mode ultrasonography was performed 7 and 14 days post-TKA for the detection of DVT. We compared the incidence of DVT between the groups and examined for side effects.

RESULTS

The demographic data of the patients in the 1- and 2-week administration groups were similar at baseline. DVT incidence did not differ significantly between the groups at 1 week post-TKA. However, it was significantly lower in the 2-week administration group (n = 0) than in the 1-week administration group (n = 7; p = 0.004) at 2 weeks post-DVT. Neither group exhibited symptomatic DVT. A total of six patients withdrew during the study period because of hepatic dysfunction.

CONCLUSIONS

Our results show that the administration of edoxaban 15 mg is more effective in preventing DVT after TKA when administered for 2 weeks than for 1 week.

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.

The effectiveness of graduated compression stockings for prevention of venous thromboembolism in orthopedic and abdominal surgery patients requiring extended pharmacologic thromboprophylaxis

OBJECTIVE

There is an increasing evidence base to support the use of extended pharmacologic thromboprophylaxis in selected surgical patients to prevent venous thromboembolism (VTE). The benefit of graduated compression stockings (GCS) in addition to extended pharmacologic thromboprophylaxis is unclear. The aim of this study was to systematically review the evidence relating to the effectiveness of using GCS in conjunction with extended pharmacologic thromboprophylaxis to prevent VTE in surgical patients.

METHODS

A literature search of MEDLINE, Embase, Cochrane Library, and ClinicalTrials.gov databases was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in April 2017. The review protocol was published on PROSPERO (CRD42017062655). Randomized controlled trials (RCTs) were eligible if one of the study arms included patients receiving extended pharmacologic thromboprophylaxis alone (>21 days) or in conjunction with GCS. Data on deep venous thrombosis (DVT), pulmonary embolism (PE), and VTE-related death were compiled. Pooled proportions of the VTE rates were determined using random-effects meta-analysis.

RESULTS

The systematic search identified 1291 studies, of which 19 studies were eligible for inclusion. No RCT directly compared extended pharmacologic thromboprophylaxis alone with GCS plus extended pharmacologic thromboprophylaxis. A total of 9824 patients from 16 RCTs were treated with extended pharmacologic thromboprophylaxis, of whom 0.81% (95% confidence interval [CI], 0.5-1.20) were diagnosed with symptomatic DVT and 0.2% (95% CI, 0.12-0.36) with PE. Three trials included 337 patients who received extended pharmacologic thromboprophylaxis in conjunction with GCS. In this group, 1.61% (95% CI, 0.03-5.43) had symptomatic DVT with no reported PE. Similar VTE rates were observed when studies in orthopedic and abdominal surgery were analyzed separately.

CONCLUSIONS

There is insufficient evidence to recommend GCS in conjunction with extended pharmacologic prophylaxis to prevent VTE in patients undergoing orthopedic and abdominal surgery. A clinical trial directly investigating this important subject is needed.

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.

Prospective, multicenter study of postoperative deep-vein thrombosis in patients with haemophilia undergoing major orthopaedic surgery

Perioperative clotting factor replacement is administered to reverse the inherent haemostatic defect in persons with haemophilia (PWH), potentially increasing their risk for developing venous thromboembolism (VTE) postoperatively. It was our objective to determine the prevalence of VTE in PWH undergoing total hip or knee arthroplasty (THA, TKA). Patients with haemophilia A or B who underwent THA or TKA were enrolled in this prospective, multicentre observational cohort study. Lower extremity venous duplex ultrasound was performed prior to surgery and 4–6 weeks after surgery. Eleven centres enrolled 51 subjects, 46 of whom completed the study. Six subjects (13.0 %) were treated with bypass agents perioperatively; the remaining 40 subjects received factor VIII or IX replacement. Intermittent pneumatic compression devices were utilised postoperatively in 23 subjects (50 %), and four subjects (8.7 %) also received low-molecular-weight heparin prophylaxis. One subject (2.2 %) with moderate haemophilia A was diagnosed with symptomatic distal deep-vein thrombosis (DVT) on day 6 following TKA. One subject (2.2 %) with severe haemophilia A was diagnosed with pulmonary embolism on day 9 following bilateral TKA. No subjects had asymptomatic DVT. Eighteen subjects (39.1 %) had major bleeding, and three subjects (6.5 %) experienced minor bleeding. The observed prevalence of ultrasound-detectable, asymptomatic DVT in PWH following TKA or THA in this study was low, but the incidence of symptomatic VTE (4.3 %, 95 % CI, 0.5–14.8 %) appeared similar to the estimated incidence in the general population without thromboprophylaxis.

New oral anticoagulants in venous thromboembolism prophylaxis in orthopaedic patients: Are they really better?

Prophylaxis against venous thromboembolism (VTE) is considered standard of care. Appropriate chemoprophylaxis for VTE has been mandated by the United States government agencies and consumer groups. However, controversies exist regarding the most clinically relevant and safe chemoprophylaxis protocols in patients undergoing joint replacement surgery. Thus, this paper reviews the clinical efficacy and safety of newer oral anticoagulants. A literature search was performed for oral anticoagulants in advanced stages of development using PubMed and abstracts from thrombosis meetings. Most clinical trial data have demonstrated equal or superior efficacy in venographic endpoints in comparison to low-molecular-weight heparins (LMWH). However, bleeding complications have been reported to occur with oral anticoagulants as frequently as or more frequently than with LMWH. Other potential complications reported include liver enzyme elevation and cardiac irregularities. It remains to be established whether newer oral anticoagulants will be better alternatives to the current standard-ofcare in real-life medical clinical practice.

Symptoms and clinical relevance: A dilemma for clinical trials on prevention of venous thromboembolism

The outcomes of thromboprophylactic trials have been debated for decades. Recently, the 9th edition of the American College of Chest Physicians (ACCP) evidence-based clinical practice guidelines based their strong recommendations only on patient-important outcomes. Practically, symptoms were considered the crucial element. Consequently, studies that primarily aimed at reducing venographic thrombi were considered less pertinent than studies that focused on symptomatic thrombosis. In the present viewpoint, we challenge the argument that “symptomatic” and “clinically relevant” are interchangeable. In particular, the case is made that asymptomatic events may be clinically relevant and that asymptomatic venographically detected thrombosis is a clinically relevant surrogate outcome for fatal pulmonary embolism.

Quality differences between private for-profit, private non-profit and public hospitals in Norway: a retrospective national register-based study of acute readmission rates following total hip and knee arthroplasties

OBJECTIVES

To compare the quality of care-using unplanned acute hospital readmissions as a quality measure-among patients treated at private for-profit hospitals (PFPs), private non-profit hospitals (PNPs) and public hospitals (PUBs) in Norway.

DESIGN

A retrospective comparative study using the Norwegian Patient Register. Readmissions were evaluated by logistic regressions both using adjustment for various patient-level and other covariates, and a two-stage model using distance as an instrumental variable.

SETTING

The Norwegian healthcare system.

POPULATION

All publicly financed patients having primary total hip (37 897 patients) or primary total knee arthroplasty (25 802 patients) at one of the three hospital types from 2009 to 2014.

PRIMARY OUTCOME MEASURE

30-day unplanned acute hospital readmission rate.

RESULTS

We found highest readmission rates among PUBs and lowest among PFPs, for both procedures. However, the patients were on average more than 2 years younger at PFPs. PFPs also treated the least severe patients, while PUBs treated the most severe. Using adjustment for various patient-level and other covariates, compared to PUBs, both PFPs and PNPs had lower odds of readmission following both procedures. However, using the instrumental variable method, the only significant difference found was a lower odds of readmission at PNPs among hip patients when compared with PUBs. No patients in our data set were readmitted to PFPs, those originally treated at PFPs were readmitted to either PNPs or PUBs, and PUBs received most of the readmitted patients across hospital types.

CONCLUSIONS

Quality differences between hospital types were small; however, PNPs had significantly lower readmission rates compared with PUBs among patients having total hip arthroplasty. PUBs received the larger part of the readmitted patients across hospital types and thus play an essential role in the care of more complex patients and for readmissions, regardless of any quality differences.

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.

Efficacy and safety of extended thromboprophylaxis for medically ill patients. A meta-analysis of randomised controlled trials

Compelling evidence suggests that the risk of pulmonary embolism (PE) and deep-vein thrombosis (DVT) persists after hospital discharge in acutely-ill medical patients. However, no studies consistently supported the routine use of extended-duration thromboprophylaxis (ET) in this setting. We performed a meta-analysis to assess efficacy and safety of ET in acutely-ill medical patients. Efficacy outcome was defined by the prevention of symptomatic DVT, PE, venous thromboembolism (VTE) and VTE-related mortality. Safety outcome was the occurrence of major bleeding (MB) and fatal bleeding (FB). Pooled odds ratios (ORs) and 95 % confidence intervals (95 %CI) were calculated for each outcome using a random effects model. Four RCTs for a total of 28,105 acutely-ill medical patients were included. ET was associated with a significantly lower risk of DVT (0.3 % vs 0.6 %, OR 0.504, 95 %CI: 0.287-0.885) and VTE (0.5 % vs 1.0 %, OR: 0.544, 95 %CI: 0.297-0.997); a non-significantly lower risk of PE (0.3 % vs 0.4 %, OR 0.633, 95 %CI: 0.388-1.034) and of VTE-related mortality (0.2 % vs 0.3 %, OR 0.687, 95 %CI: 0.445-1.059) and with a significantly higher risk of MB (0.8 % vs 0.4 %, OR 2.095, 95 %CI: 1.333-3.295). No difference in FB was found (0.06 % vs 0.03 %, OR 1.79, 95 %CI: 0.384-8.325). The risk benefit analysis showed that the NNT for DVT was 339, for VTE was 239, and the NNH for MB was 247. Results of our meta-analyses focused on clinical important outcomes did not support a general use of antithrombotic prophylaxis beyond the period of hospitalization in acutely-ill medical patients.

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.

Prophylaxis for Venous Thromboembolism Following Total Knee Arthroplasty: A Survey of Korean Knee Surgeons

PURPOSE

The purpose of this study is to provide information on the actual status and prevailing trend of prophylaxis for venous thromboembolism (VTE) following total knee arthroplasty (TKA) in South Korea.

MATERIALS AND METHODS

The Korean Knee Society (KKS) developed a questionnaire with 6 clinical questions on VTE. The questionnaire was distributed to all members of KKS by both postal and online mail. Participants were asked to supply details on their specialty and to select methods of prophylaxis they employ. Of the total members of KKS, 27.9% participated in the survey.

RESULTS

The percentage of surgeons who routinely performed prophylaxis for VTE was 60.4%; 19.4% performed prophylaxis depending on the patient's health condition; and the remaining 20.2% never implemented prophylaxis after surgery. The common prophylactic methods among the responders were compression stocking (72.9%), pneumatic leg compression (63.3%), perioral direct factor Xa inhibitor (46.9%), and low-molecular-weight heparin (39.5%). For the respondents who did not perform prophylaxis, the main reason (51.5%) was the low risk of postoperative VTE considering the low incidences in Asians.

CONCLUSIONS

The present study involving members of the KKS will help to comprehend the actual status of VTE prevention in South Korea. The results of this study may be useful to design VTE guidelines appropriate for Koreans in the future.

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.

Cost-Effectiveness of Venous Thromboembolism Prophylaxis after Total Hip Replacement

Objective:

To determine the cost-effectiveness of three strategies used for the prevention of venous thromboem-bolism (VTE) in patients undergoing total hip replace-ment (THR), and to perform a sensitivity analysis comparing VTE rates based on different methods of detection.

Methods:

In this cost-effectiveness analysis, three strategies of prophylaxis of postoperative VTE and THR were compared: (1) low-molecular-weight heparin (LMWH); Enoxaparin, (2) warfarin and (3) a combination of warfarin, heparin (UFH), graduated stockings and sequential long-leg pneumatic compression devices. The model estimates were based on pooled data from the published literature and from personal data in our series of hip replacement patients. Expected direct costs of VTE care, including prophylaxis, diagnosis and manage-ment of thromboembolic and hemorrhagic complications, were estimated for a hypothetical cohort of 100 patients in 2001 US dollars from data available for patients hospitalized at Evanston Northwestern Health-care. A sensitivity analysis was performed with different rates of VTE based on routine venography, routine duplex ultrasound, or selective diagnosis and treatment of symptomatic patients.

Results:

When venography was used to diagnose VTE, the cost of warfarin or LMWH treatment was $118 422 and $104 732 per 100 patients, respectively, providing cost savings of $ 13 690 per hundred patients for LMWH. When VTE rates were based on duplex ultrasound diagnoses, LMWH resulted in cost savings of $4602 and $1345 per 100 patients compared with the use of warfarin or the combined approach, respectively. However, when the rates of VTE were based on confirmed symptomatic cases, the use of LMWH resulted in an increased cost of $4486 and $10015 per 100 patients compared with warfarin and the combined approach, respectively.

Conclusions:

The use of LMWH for the prevention of VTE after THR was more cost-effective than using warfarin or the combined approach, when the VTE rate was based on routine venography or duplex ultrasound. However, the combined approach was more cost-effective than the use of warfarin or LMWH alone when only patients with confirmed, symptomatic VTE were treated.

Risk of and Prophylaxis for Venous Thromboembolism in Hospital Patients

Objective:

To review the published clinical data on prophylaxis for thromboembolism in order to develop general guidelines to encourage the establishment of local protocols for management.

Data sources:

Published papers on thromboembolism over the period 1991–1997 were identified by Medline search and/or from the authors' personal literature collections and reviewed.

Study selection:

A total of 981 studies were identified. Only those papers reporting randomized studies with clearly defined diagnostic methods and clear end-points were included in this review.

Data extraction:

The available evidence for each specialty was summarized and reviewed by the authors responsible for each specialty, prior to presentation and discussion of their findings within the group. Where a consensus opinion was achieved in a speciality, general guidelines for thromboprophylaxis were summarized. Where a consensus could not be agreed, recommendations for further work were made.

Data synthesis:

There is evidence to support the preferred use of low-molecular-weight heparins (LMWHs) over unfractionated heparin (UFH) in orthopaedic surgery, major trauma and general surgery. However, the ideal duration of thromboprophylaxis has yet to be defined. The use of once daily subcutaneous administration of LMWH offers major practical advantages and may have significant cost saving implications. Further work is required to investigate the use of thromboprophylaxis in minimal access surgery, trauma, elective lower limb surgery, hip fracture and pregnancy; to compare the efficacy of LMWH and mechanical prophylaxis; and to investigate extended prophylaxis after discharge.

Conclusions:

There is overwhelming evidence that thromboembolic prophylaxis reduces the incidence of postoperative deep vein thrombosis and pulmonary embolism. Recommendations concerning the management of these patients when stratified into low, moderate and high risk are made with the suggestion that hospitals develop their own guidelines for the treatment of these patients.

Management of Venous Thromboembolisms: Part I. The Consensus for Deep Vein Thrombosis

Deep vein thrombosis (DVT) is a potentially catastrophic condition because thrombosis, left untreated, can result in detrimental pulmonary embolism. Yet in the absence of thrombosis, anticoagulation increases the risk of bleeding. In the existing literature, knowledge about the epidemiology of DVT is primarily based on investigations among Caucasian populations. There has been little information available about the epidemiology of DVT in Taiwan, and it is generally believed that DVT is less common in Asian patients than in Caucasian patients. However, DVT is a multifactorial disease that represents the interaction between genetic and environmental factors, and the majority of patients with incident DVT have either inherited thrombophilia or acquired risk factors. Furthermore, DVT is often overlooked. Although symptomatic DVT commonly presents with lower extremity pain, swelling and tenderness, diagnosing DVT is a clinical challenge for physicians. Such a diagnosis of DVT requires a timely systematic assessment, including the use of the Wells score and a D-dimer test to exclude low-risk patients, and imaging modalities to confirm DVT. Compression ultrasound with high sensitivity and specificity is the front-line imaging modality in the diagnostic process for patients with suspected DVT in addition to conventional invasive contrast venography. Most patients require anticoagulation therapy, which typically consists of parenteral heparin bridged to a vitamin K antagonist, with variable duration. The development of non-vitamin K oral anticoagulants has revolutionized the landscape of venous thromboembolism treatment, with 4 agents available,including rivaroxaban, dabigatran, apixaban, and edoxaban. Presently, all 4 drugs have finished their large phase III clinical trial programs and come to the clinical uses in North America and Europe. It is encouraging to note that the published data to date regarding Asian patients indicates that such new therapies are safe and efficacious. Ultimately, our efforts to improve outcomes in patients with DVT rely on the awareness in the scientific and medical community regarding the importance of DVT.

KEY WORDS

Combination therapy; Hypertension; α1-blocker.

Anticoagulants (extended duration) for prevention of venous thromboembolism following total hip or knee replacement or hip fracture repair

BACKGROUND

The optimal duration of thromboprophylaxis after total hip or knee replacement, or hip fracture repair remains controversial. It is common practice to administer prophylaxis using low-molecular-weight heparin (LMWH) or unfractionated heparin (UFH) until discharge from hospital, usually seven to 14 days after surgery. International guidelines recommend extending thromboprophylaxis for up to 35 days following major orthopaedic surgery but the recommendation is weak due to moderate quality evidence. In addition, recent oral anticoagulants that exert effect by direct inhibition of thrombin or activated factor X lack the need for monitoring and have few known drug interactions. Interest in this topic remains high.

OBJECTIVES

To assess the effects of extended-duration anticoagulant thromboprophylaxis for the prevention of venous thromboembolism (VTE) in people undergoing elective hip or knee replacement surgery, or hip fracture repair.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Specialised Register (last searched May 2015) and CENTRAL (2015, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials assessing extended-duration thromboprophylaxis (five to seven weeks) using accepted prophylactic doses of LMWH, UFH, vitamin K antagonists (VKA) or direct oral anticoagulants (DOAC) compared with short-duration thromboprophylaxis (seven to 14 days) followed by placebo, no treatment or similar extended-duration thromboprophylaxis with LMWH, UFH, VKA or DOACs in participants undergoing hip or knee replacement or hip fracture repair.

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 16 studies (24,930 participants); six compared heparin with placebo, one compared VKA with placebo, two compared DOAC with placebo, one compared VKA with heparin, five compared DOAC with heparin and one compared anticoagulants chosen at investigators' discretion with placebo. Three trials included participants undergoing knee replacement. No studies assessed hip fracture repair.Trials were generally of good methodological quality. The main reason for unclear risk of bias was insufficient reporting. The quality of evidence according to GRADE was generally moderate, as some comparisons included a single study, low number of events or heterogeneity between studies leading to wide CIs.We showed no difference between extended-duration heparin and placebo in symptomatic VTE (OR 0.59, 95% CI 0.35 to 1.01; 2329 participants; 5 studies; high quality evidence), symptomatic deep vein thrombosis (DVT) (OR 0.73, 95% CI 0.39 to 1.38; 2019 participants; 4 studies; moderate quality evidence), symptomatic pulmonary embolism (PE) (OR 0.61, 95% CI 0.16 to 2.33; 1595 participants; 3 studies; low quality evidence) and major bleeding (OR 0.59, 95% CI 0.14 to 2.46; 2500 participants; 5 studies; moderate quality evidence). Minor bleeding was increased in the heparin group (OR 2.01, 95% CI 1.43 to 2.81; 2500 participants; 5 studies; high quality evidence). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration VKA and placebo (one study, 360 participants) for symptomatic VTE (OR 0.10, 95% CI 0.01 to 1.94; moderate quality evidence), symptomatic DVT (OR 0.13, 95% CI 0.01 to 2.62; moderate quality evidence), symptomatic PE (OR 0.32, 95% CI 0.01 to 7.84; moderate quality evidence) and major bleeding (OR 2.89, 95% CI 0.12 to 71.31; low quality evidence). Clinically relevant non-major bleeding and minor bleeding were not reported.Extended-duration DOAC showed reduced symptomatic VTE (OR 0.20, 95% CI 0.06 to 0.68; 2419 participants; 1 study; moderate quality evidence) and symptomatic DVT (OR 0.18, 95% CI 0.04 to 0.81; 2459 participants; 2 studies; high quality evidence) compared to placebo. No differences were found for symptomatic PE (OR 0.25, 95% CI 0.03 to 2.25; 1733 participants; 1 study; low quality evidence), major bleeding (OR 1.00, 95% CI 0.06 to 16.02; 2457 participants; 1 study; low quality evidence), clinically relevant non-major bleeding (OR 1.22, 95% CI 0.76 to 1.95; 2457 participants; 1 study; moderate quality evidence) and minor bleeding (OR 1.18, 95% CI 0.74 to 1.88; 2457 participants; 1 study; moderate quality evidence).We showed no difference between extended-duration anticoagulants chosen at investigators' discretion and placebo (one study, 557 participants, low quality evidence) for symptomatic VTE (OR 0.50, 95% CI 0.09 to 2.74), symptomatic DVT (OR 0.33, 95% CI 0.03 to 3.21), symptomatic PE (OR 1.00, 95% CI 0.06 to 16.13), and major bleeding (OR 5.05, 95% CI 0.24 to 105.76). Clinically relevant non-major bleeding and minor bleeding were not reported.We showed no difference between extended-duration VKA and heparin (one study, low quality evidence) for symptomatic VTE (OR 1.64, 95% CI 0.85 to 3.16; 1279 participants), symptomatic DVT (OR 1.36, 95% CI 0.69 to 2.68; 1279 participants), symptomatic PE (OR 9.16, 95% CI 0.49 to 170.42; 1279 participants), major bleeding (OR 3.87, 95% CI 1.91 to 7.85; 1272 participants) and minor bleeding (OR 1.33, 95% CI 0.64 to 2.76; 1279 participants). Clinically relevant non-major bleeding was not reported.We showed no difference between extended-duration DOAC and heparin for symptomatic VTE (OR 0.70, 95% CI 0.28 to 1.70; 15,977 participants; 5 studies; low quality evidence), symptomatic DVT (OR 0.60, 95% CI 0.11 to 3.27; 15,977 participants; 5 studies; low quality evidence), symptomatic PE (OR 0.91, 95% CI 0.43 to 1.94; 14,731 participants; 5 studies; moderate quality evidence), major bleeding (OR 1.11, 95% CI 0.79 to 1.54; 16,199 participants; 5 studies; high quality evidence), clinically relevant non-major bleeding (OR 1.08, 95% CI 0.90 to 1.28; 15,241 participants; 4 studies; high quality evidence) and minor bleeding (OR 0.95, 95% CI 0.82 to 1.10; 11,766 participants; 4 studies; high quality evidence).

AUTHORS' CONCLUSIONS

Moderate quality evidence suggests extended-duration anticoagulants to prevent VTE should be considered for people undergoing hip replacement surgery, although the benefit should be weighed against the increased risk of minor bleeding. Further studies are needed to better understand the association between VTE and extended-duration oral anticoagulants in relation to knee replacement and hip fracture repair, as well as outcomes such as distal and proximal DVT, reoperation, wound infection and healing.

Meta-analysis and suggested guidelines for prevention of venous thromboembolism (VTE) in foot and ankle surgery

PURPOSE

To perform a meta-analysis investigating venous thromboembolism (VTE) following isolated foot and ankle surgery and propose guidelines for VTE prevention in this group of patients.

METHODS

Following a PRISMA compliant search, 372 papers were identified and meta-analysis performed on 22 papers using the Critical Appraisal Skills Programme and Centre for Evidence-Based Medicine level of evidence.

RESULTS

43,381 patients were clinically assessed for VTE and the incidence with and without chemoprophylaxis was 0.6% (95% CI 0.4-0.8%) and 1% (95% CI 0.2-1.7%), respectively. 1666 Patients were assessed radiologically and the incidence of VTE with and without chemoprophylaxis was 12.5% (95% CI 6.8-18.2%) and 10.5% (95% CI 5.0-15.9%), respectively. There was no significant difference in the rates of VTE with or without chemoprophylaxis whether assessed clinically or by radiological criteria. The risk of VTE in those patients with Achilles tendon rupture was greater with a clinical incidence of 7% (95% CI 5.5-8.5%) and radiological incidence of 35.3% (95% CI 26.4-44.3%).

CONCLUSION

Isolated foot and ankle surgery has a lower incidence of clinically apparent VTE when compared to general lower limb procedures, and this rate is not significantly reduced using low molecular weight heparin. The incidence of VTE following Achilles tendon rupture is high whether treated surgically or conservatively. With the exception of those with Achilles tendon rupture, routine use of chemical VTE prophylaxis is not justified in those undergoing isolated foot and ankle surgery, but patient-specific risk factors for VTE should be used to assess patients individually.

LEVEL OF EVIDENCE

II.

Low dose compared to variable dose Warfarin and to Fondaparinux as prophylaxis for thromboembolism after elective hip or knee replacement surgery; a randomized, prospective study

Background

Deep vein thrombosis (DVT) and pulmonary emboli (PE), known together as venous thromboembolic (VTE) disease remain major complications following elective hip and knee surgery. This study compares three chemoprophylactic regimens for VTE following elective primary unilateral hip or knee replacement, one of which was designed to minimize risk of post-operative bleeding.

Methods

Patients were randomized and stratified for hip vs. knee to receive A: variable dose warfarin (first dose on the night preceding surgery with subsequent target INR 2.0–2.5), B: 2.5 mg fondaparinux daily starting 6–18 h postoperatively, or C: fixed 1.0 mg dose warfarin daily starting 7 days preoperatively. All treatments continued until bilateral leg venous ultrasound day 28 ± 2 or earlier upon a VTE event. The study examined primary endpoints including leg DVT, PE or death due to VTE and secondary endpoints including effects on D-dimer, estimated blood loss (EBL) at surgery and hemorrhagic complications.

Results

Three hundred fifty-five patients were randomized. None was lost to follow-up. Taking 1.0 mg warfarin for seven days preoperatively did not prolong the prothrombin time (PT). Two patients in Arm C had asymptomatic distal DVT. One major bleed occurred in Arm B and one in Arm C (ischemic colitis). Elevated d-dimer did not predict delayed VTE for one year.

Conclusions

Fixed low dose warfarin started preoperatively is equivalent to two other standards of care under study (95 % CI: -0.0428, 0.0067 for both) as VTE prophylaxis for the patients having elective major joint replacement surgery.

Trial registration

ClinicalTrials.gov identifier # NCT00767559

FDA IND: 103,716

Patient-reported compliance with thromboprophylaxis using an oral factor Xa inhibitor (rivaroxaban) following total hip and total knee arthroplasty

This prospective study examines patient non-compliance (NC) for an oral factor Xa inhibitor (Rivaroxaban) when used as venous thromboembolic (VTE) prophylaxis following lower limb arthroplasty. A total of 3145 patients underwent surgery from May 2010 to December 2011. At 6 weeks patients completed an anonymous self-administered questionnaire. Postoperatively 2947 (94%, 2947/3145) received Rivaroxaban. 2824 (96%, 2824/2947) completed all in-hospital doses. Seven percent (203/2824) of patients did not attend the 6-week follow-up. Two thousand one hundred sixty-three (83%, 2163/2621) completed all prescribed doses, 98 (4%, 98/2621) were NC and 360 (14%, 360/2621) had incomplete data. Gender, age, body mass index and preoperative hemoglobin all correlated with NC (p < 0.05). Type and side of surgery did not correlate with compliance (p > 0.05). Patient-reported NC for Rivaroxaban is 4% which compares favorably to other VTE prophylaxis modalities.

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.

Review article: Anti-embolism stockings

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

[Physical prophylaxis for thromboembolism. Current state of knowledge on use of medical thromboprophylaxis stockings]

BACKGROUND

Thromboprophylaxis in surgery patients is a combination of physical and medical thromboprophylaxis. The established mode of physical thromboprophylaxis in Germany is graduated compression stockings. Recent publications from various authors generally scrutinized the additional benefits of physical prophylaxis in patients who received medical thromboprophylaxis.

MATERIAL AND METHODS

A thorough search was carried out in PubMed and Medline. The focus of the search was on studies which investigated the advantages of physical thromboprophylaxis in surgery patients.

RESULTS

The low amount of evidence available for prophylaxis of thromboembolism in surgery patients was mainly deduced from trials that had a combination of medical and physical thromboprophylaxis as part of the study protocol. The results of experimental investigations were able to show a statistically highly significant reduction of the diameter of lower extremity veins.

CONCLUSION

There is no current evidence to support refraining from routine use of graduated compression stockings in surgery patients. This is also the case for the new oral anti-Xa and anti-IIa inhibitors.