Insufficient Evidence for Routine Use of Thromboprophylaxis in Ambulatory Patients with an Isolated Lower Leg Injury Requiring Immobilization: Results of a Meta-Analysis

Abstract Background:   There are no generally accepted guidelines for the prevention of venous thromboembolism (VTE) in ambulatory patients requiring immobilization after an isolated lower leg injury. Our objective was to evaluate the effectiveness and safety of pharmacological interventions for preventing VTE in these patients. Study Design:   Meta-analysis of randomized controlled trials. Materials and Methods:   We searched PubMed/Medline, EMBASE and the Cochrane Central Register of Controlled Trials for trials with random allocation of thromboprophylaxis, notably low molecular weight heparin (LMWH) versus no prophylaxis or placebo, in ambulatory patients with below-knee or lower leg (including the knee joint) immobilization. Outcome was analyzed using MIX to calculate the pooled risk ratio/relative risk (RR) for each outcome, along with its 95% confidence interval (CI). Results:   The RR of asymptomatic deep vein thrombosis (DVT) was 0.66 (95% CI 0.44; 1.02) for below-knee immobilization and 0.51 (95% CI 0.37; 0.70) for lower leg immobilization. Low molecular weight heparin versus no prophylaxis or placebo was evaluated. The incidence of symptomatic DVT and PE was too low to show any statistically significant difference between thromboprophylaxis and controls in both groups. Although only one adverse bleeding event was considered to bemajor, the RR for any adverse bleeding event was 1.94 (95% CI 1.03; 3.67). Conclusion:   There is insufficient evidence to warrant routine use of thromboprophylaxis in ambulatory patients with below-knee or lower leg immobilization after an isolated lower leg injury. The incidence of symptomatic VTE is too low to show a relevant clinical benefit from thromboprophylaxis.     

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

BackgroundDirect 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.MethodsThe 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.ResultsThe 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.ConclusionAll 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.     

多模式预防措施对老年关节置换术后静脉血栓栓塞症发生及转归的影响

目的分析采用多模式血栓预防措施后,老年初次髋、膝关节置换术后静脉血栓栓塞症（VTE）的发生和转归情况。 方法回顾性收集2015年1月至2017年6月行初次单侧髋、膝关节置换的老年患者375例（年龄≥60岁）,所有患者均接受抗凝药物、足底小腿静脉气压泵、加强踝泵和早期下地等康复预防以及减少围手术期脱水等多模式血栓预防措施,术后采用彩色多普勒超声检查双侧下肢深静脉血栓（DVT）的发生情况,对有症状患者行肺动脉CT造影排查肺动脉栓塞（PE）。 结果共349名患者获完整随访,随访率92.5%。随访期间无症状性PE,DVT共38例,总发生率为10.9%,均为远端DVT。手术同侧DVT 38例,双侧3例。症状性DVT共27例（27/38,71.1%）,无症状性DVT 11例（11/38,29.0%）。单纯腓肠肌间静脉血栓29例,单条小腿静脉血栓3例,混合静脉血栓6例。接受不同手术方式的患者DVT发生率差别有统计学意义（χ²=0.000,P<0.001）,其中接受全膝关节置换手术患者DVT的发生率为16.3%,显著高于单髁关节置换手术组的4.7%。单纯腓肠肌间静脉血栓未予药物治疗,其他DVT口服利伐沙班抗凝治疗4 w。术后8 w,有26例（26/38,68.4%）血栓完全消融,12例（12/38,31.6%）血栓未完全消融,但所有DVT相关临床表现均消失,无残留血栓后遗症,且无血栓进展或新发PE。 结论采取多模式预防措施后,老年关节置换术后VTE发生率低,且均为远端DVT,经观察或短程抗凝治疗,症状消失并无后遗症。     

Does thromboprophylaxis reduce symptomatic venous thromboembolism in patients with below knee cast treatment for foot and ankle trauma? A systematic review and meta-analysis

Background

Our aim was to determine the evidence for thromboprophylaxis for prevention of symptomatic venous thromboembolism (VTE) in adults with foot or ankle trauma treated with below knee cast or splint. Our secondary aim was to report major bleeding events.

Chemoprophylaxis for venous thromboembolism in pelvic and/or acetabular fractures: A systematic review

BackgroundIt is unclear which pharmacological agents, and at what dosage and timing, are most effective for venous thromboembolism (VTE) prophylaxis in patients with pelvic/acetabular fractures.MethodsWe searched the Cochrane Database of Systematic Reviews, Embase, Web of Science, EBSCO, and PubMed on October 3, 2020, for English-language studies of VTE prophylaxis in patients with pelvic/acetabular fractures. We applied no date limits. We included studies that compared efficacy of pharmacological agents for VTE prophylaxis, timing of administration of such agents, and/or dosage of such agents. We recorded interventions, sample sizes, and VTE incidence, including deep vein thrombosis (DVT) and pulmonary embolism.ResultsTwo studies (3604 patients) compared pharmacological agents, reporting that patients who received direct oral anticoagulants (DOACs) were less likely to develop DVT than those who received low molecular weight heparin (LMWH) (p < 0.01). Compared with unfractionated heparin (UH), LMWH was associated with lower odds of VTE (odds ratio [OR] = 0.37, 95% confidence interval [CI]: 0.22–0.63) and death (OR = 0.27, 95% CI: 0.10–0.72). Three studies (3107 patients) compared timing of VTE prophylaxis, reporting that late prophylaxis was associated with higher odds of VTE (OR = 1.9, 95% CI: 1.2–3.2) and death (OR = 4.0, 95% CI: 1.5–11) and higher rates of symptomatic DVT (9.2% vs. 2.5%, p = 0.03; and 22% vs. 3.1%, p = 0.01). One study (31 patients) investigated dosage of VTE prophylaxis, reporting that a higher proportion of patients with acetabular fractures were underdosed (23% of patients below range of anti–Factor Xa [aFXa] had acetabular fractures vs. 4.8% of patients within adequate range of aFXa, p<0.01).Conclusions: Early VTE chemoprophylaxis (within 24 or 48 h after injury) was better than late administration in terms of VTE and death. Many patients with acetabular fractures are underdosed with LMWH, with inadequate aFXa levels. Compared with UH, LMWH was associated with lower odds of VTE and death. DOACs were associated with lower risk of DVT compared with LMWH.Level of Evidence: III, systematic review of retrospective cohort studies.     

The survival benefit of low molecular weight heparin over unfractionated heparin in pediatric trauma patients

IntroductionVenous thromboembolism (VTE) prophylaxis in pediatric patients is controversial and is mainly dependent on protocols derived from adult practices. Our study aimed to compare outcomes among pediatric trauma patients who received low molecular weight heparin (LMWH) compared to those who received unfractionated heparin (UFH).MethodsWe performed 2 years (2015–2016) retrospective analysis of the Pediatrics ACS-TQIP database. Pediatric trauma patients (age ≤ 17) who received thromboprophylaxis with either LMWH or UFH were included. Patients were stratified into three age groups. Analysis of each subgroup and the entire cohort was performed. Outcome measures included VTE events (deep vein thrombosis [DVT] and pulmonary embolism [PE]), hospital and ICU length of stay (LOS) among survivors, and mortality. Propensity score matching was used to match the two cohorts LMWH vs UFH.ResultsA matched cohort of 1,678 pediatric trauma patients was analyzed. A significant difference in survival, DVT events, and in-hospital LOS was seen in the age groups above 9 years. Overall, the patients who received LMWH had lower mortality (1.4% vs 3.6%, p < 0.01), DVT (1.7% vs 3.7%, p < 0.01), and hospital LOS among survivors (7 days vs 9 days, p < 0.01) compared to those who received UFH. There was no significant difference in the ICU LOS among survivors and the incidence of PE between the two groups.ConclusionLMWH is associated with increased survival, lower rates of DVT, and decreased hospital LOS compared to UFH among pediatric trauma patients age 10–17 years.Level of EvidenceLevel III Prophylactic.Study TypeProphylactic.     

Mechanical prophylaxis,early mobilisation and risk stratification: as effective as drugs for low risk patients undergoing primary joint replacement. Results in 13,384 patients

IntroductionCurrent NICE Guidelines state that all patients undergoing total hip and knee arthroplasty should be given both mechanical and chemical prophylaxis. At our institution, a targeted thromboprophylaxis policy has been in place since October 1999. The aim of this study was to calculate our venous thromboembolism rates and compare these to published rates in the literature.MethodsAll patients are pre-operatively assessed for their VTE risk. Patients are stratified into high or low risk: all patients received mechanical thromboprophylaxis and the higher risk patients now receive chemical and mechanical thromboprophylaxis post op. Patients are reviewed at 2, 6 and 52 weeks and with annual postal questionnaires and clinical and radiological review at 5 and 10yrs.Results13,384 primary THA and TKAs were entered into the database. The overall rate of clinically apparent DVT and overall PE rates of 0.48% and 0.42% respectively. 86.16% of our patients were low risk, of these 23.3% of patients were on Aspirin/Clopidogrel with mechanical thromboprophylaxis and 76.7% of patients had mechanical prophylaxis alone. There was no statistical difference between the DVT or PE rates in the low risk groups.ConclusionOur results show that use of early mobilisation and mechanical prophylaxis within an Enhanced Recovery Programme results in comparable VTE rates to chemical prophylaxis for all, which is reflected in the literature. Our results question the need for chemical thromboprophylaxis or extended use of mechanical thromboprophylaxis in “lower risk” patients if a risk stratification policy is used in the context of modern surgical approaches.     

A Randomised Open-Label Trial Comparing Long-term Sub-Cutaneous Low-Molecular-weight Heparin Compared with Oral-Anticoagulant Therapy in the Treatment of Deep Venous Thrombosis

ObjectiveTo evaluate whether low-molecular-weight heparin (LMWH) could be equally (or more) effective than oral anti-vitamin-K agents (AVK) in the long-term treatment of deep venous thrombosis (DVT).DesignA randomised, open-label trial.Material and methodsIn this trial, 241 patients with symptomatic proximal DVT of the lower limbs confirmed by duplex ultrasound scan were included. After initial LMWH, patients received 6 months of treatment with full therapeutic dosage of tinzaparin or acenocoumarol. The primary outcome was the 12-month incidence of symptomatic recurrent venous thrombo-embolism (VTE). Duplex scans were performed at 6 and 12 months.ResultsDuring the 12-month period, six patients (5%) of 119 who received LMWH and 13 (10.7%) of 122 who received AVK had recurrent VTE (p = 0.11). In patients with cancer, recurrent VTE tended to be lower in the LMWH group (two of 36 [5.5%]) vs. seven of 33 [21.2%]; p = 0.06). One major bleeding occurred in the LMWH group and three in the AVK group. Venous re-canalisation increased significantly at 6 months (73.1% vs. 47.5%) and at 12 months (91.5% vs. 69.2%) in the LMWH group.ConclusionsTinzaparin was more effective than AVK in achieving re-canalisation of leg thrombi. Long-term tinzaparin was at least as efficacious and safe as AVK for preventing recurrent VTE, especially in patients with cancer.     

Dalteparin Vs Low-Dose Unfractionated Heparin for Prophylaxis Against Clinically Evident Venous Thromboembolism in Acute Traumatic Spinal Cord Injury: A Retrospective Cohort Study

Background: When venous thromboembolism (VTE) includes deep-vein thrombosis (DVT) and pulmonary embolism (PE), patients with acute traumatic spinal cord injury (SCI) have the highest incidence of VTE among all hospitalized groups, with PE the third most common cause of death. Although low-molecular-weight heparin (LMWH) outperforms low-dose unfractionated heparin (LDUH) in other patient populations, the evidence in SCI remains less robust.

Objective: To determine whether the efficacy for LMWH shown in previous SCI surveillance studies (eg, routine Doppler ultrasound) would translate into real-world effectiveness in which only clinically evident VTE is investigated (ie, after symptoms or signs present).

Methods: A retrospective cohort study was conducted of 90 patients receiving LMWH dalteparin (5,000 U daily) or LDUH (5,000 U twice daily) for VTE prophylaxis after acute traumatic SCI. The incidence of radiographically confirmed VTE was primarily analyzed, and secondary outcomes included complications of bleeding and heparin-induced thrombocytopenia.

Results: There was no statistically significant association (p = 0.7054) between the incidence of VTE (7.78% overall) and the type of prophylaxis received (LDUH 3/47 vs dalteparin 4/43). There was no significant differences in complications, location of VTE, and incidence of fatal PE. Paraplegia (as opposed to tetraplegia) was the only risk factor identified for VTE.

Conclusions: There continues to be an absence of definitive evidence for dalteparin (or other LMWH) over LDUH as the choice for VTE prophylaxis in patients with SCI. Novel approaches to VTE prophylaxis are urgently required for this population, whose risk of fatal PE has not decreased over the last 25 years.     

Thromboembolic prophylaxis in head trauma and multiple-trauma patients

The association between trauma and venous thromboembolism (VTE) is well recognized. VTE consists mainly of deep venous thrombosis (DVT) and pulmonary embolism, a complication that leads to mortality in nearly 50% of cases. Without thromboprophylaxis, the risk of DVT exceeds 50%, but even with routine use of prophylaxis,one third of patients may develop DVT. Despite these findings, appropriate DVT prophylaxis is often not prescribed in trauma patients, mainly because of fear that VTE prophylaxis increases bleeding in injured tissues. Pharmacological VTE prophylaxis is based on the use of low-molecular weight heparins (LMWH). Once-daily or twice-daily LMWH protocols started within 36 h of trauma and continued throughout the hospital stay, or once-daily LMWH followed by a twice-daily protocol are possible options. Mechanical VTE prophylaxis by graduated compression stockings or intermittent pneumatic compression provides suboptimal protection, and its use is recommended only in combination with LMWH prophylaxis unless active bleeding is not controlled. The routine use of VTE prophylaxis in trauma patients is a standard of care. The use of LMWH, started once primary hemostasis has been accomplished, is safe, efficacious and cost-effective in the majority of trauma patients, including TBI patients.     

Efficacy and Safety of Mechanical IVC Filtration for Preventing Pulmonary Embolism in High-Risk Orthopedic Patients Undergoing Total Hip or Knee Arthroplasty

BackgroundTo determine the efficacy and safety of inferior vena cava (IVC) filters in preventing pulmonary embolism (PE) in high-risk patients undergoing hip or knee arthroplasty.Methods2857 hip or knee arthroplasty procedures between January 2013 and December 2018 were retrospectively reviewed. Patients with a preoperative history of venous thromboembolism (VTE), either PE or deep venous thrombosis (DVT), were categorized as high-risk patients. The incidence of overall VTE, PE, and DVT were compared between patients with filters and those without. The subgroup analysis was also performed by patient risk, and filter status and the incidence of VTE, PE, and DVT were compared. Variables such as filter placement, history of hypercoagulability etcetra were evaluated as risk factors for the development of postoperative VTE.ResultsIn the high-risk group, the use of IVC filters was significantly associated with a lower incidence of pulmonary embolism (0.8% vs 5.5%, P = .028). When compared with the low-risk group, the high-risk group had significantly higher incidence of PE (3.8% vs 2.0%, P = .038), DVT (11.6% vs 5.3%, P < .001), and overall VTE (15.0% vs 6.8%, P < .001). The history of VTE was associated with postoperative VTE (P < .001), PE (P = .042), and DVT (P < .001). There was no significant correlation between filter placement and postoperative VTE, DVT, or PE in the low-risk group. Filter retrieval was successful in 100% (96/96) of attempted patients with no complications.ConclusionThe use of IVC filters is significantly associated with a lower incidence in pulmonary embolism in high-risk arthroplasty patients. High-risk patients demonstrated an incidence of postoperative VTE over two times greater than other patients. Prophylactic placement of IVC filters in hip/knee arthroplasty is safe.     

D-dimer monitoring combined with ultrasonography improves screening for asymptomatic venous thromboembolism in acute spinal cord injury

Objective: We compared screening methods for asymptomatic venous thromboembolism (VTE) in patients with acute spine and spinal cord injuries (SCI). Patients were screened by D-dimer monitoring alone (DS group) or by D-dimer monitoring combined with ultrasonography (DUS group).

Design: Prospective cohort study.

Setting: One department of a university hospital in Japan.

Participants: 114 patients treated for acute SCI between 2011 and 2017.

Interventions: N/A.

Outcome Measures: D-dimers were measured upon admission and 1, 3, 5, 7, and 14 days thereafter. DUS-group patients also underwent an ultrasound 7 days after admission. If ultrasonography indicated deep venous thrombosis (DVT), or if D-dimer levels increased to ≥?10?µg/mL, the patient was assessed for VTE, including DVT or pulmonary embolism (PE), by contrast venography. We analyzed the incidence of VTE detected in the DS and DUS groups.

Results: In the DS group, D-dimers were elevated (≥?10?µg/mL) in 15 of 70 patients (21.4%), and 9 of the 15 had asymptomatic VTE (12.9%, DVT 11.4%, PE 5.7%). In the DUS group, one patient developed VTE on day 4, and D-dimers were elevated in 13 of 43 patients (30.2%), ultrasonography indicated DVT in 12 patients (27.9%), and asymptomatic VTE was diagnosed in 12 patients (27.9%, DVT 27.9%, PE 4.7%). The DUS group had a higher incidence of DVT (P?=?0.002) and VTE (P?=?0.042) than the DS group.

Conclusions: Combined D-dimer and ultrasound screening in patients with acute SCI improved the detection of VTE, including PE, compared with D-dimer screening alone.     

Are factor Xa inhibitors effective thromboprophylaxis following hip fracture surgery?: A large national database study

IntroductionThe purpose of this study was to evaluate the effectiveness of Factor Xa inhibitors (XaI) for thromboprophylaxis following hip fracture surgery in a large cohort of patients, and compare XaI against warfarin and enoxaparin.MethodsPatients undergoing hip fracture surgery from 2007 to 2015 were identified in a large claims database. Patients prescribed warfarin, XaI, or enoxaparin within 2 weeks of surgery were identified and grouped into cohorts. Medical comorbidities and complication incidences, including deep venous thrombosis (DVT), pulmonary embolism (PE), and bleeding complications were calculated. Chi-square analysis was performed and adjusted residuals calculated to determine significant differences.ResultsDVT rates were significantly different between groups at thirty days only (5.03% warfarin, 2.91% XaI, 3.48% enoxaparin, p = 0.047). PE rates were significantly different at all time points; enoxaparin had the lowest rates. There were no differences in the rates of other complications.DiscussionXaI are an option for thromboprophylaxis in hip fracture patients, although their possible decreased effectiveness against PE compared to enoxaparin should be considered.ConclusionsThis study compares the effectiveness of Factor Xa inhibitors to warfarin and enoxaparin for hip fracture patients, using a large national database. In this study, Factor Xa inhibitors had similar effectiveness for DVT prophylaxis compared to these agents.     

Venous Thromboembolism Rates Did Not Decrease in Lower Extremity Revision Total Joint Arthroplasty From 2008 to 2016

BackgroundIn revision total knee arthroplasty (rTKA) and revision total hip arthroplasty (rTHA), venous thromboembolism (VTE) has been reported to be a relatively common and potentially serious complication. To mitigate this risk, strategies such as rapid recovery programs and thromboprophylaxis guidelines have been utilized. This study sought to identify the annual incidence and recent trends of VTE (defined as the presence of deep vein thrombosis [DVT] and/or pulmonary embolism [PE] in the same patient), DVT, PE, and mortality in the 30-day period after rTKA and rTHA.MethodsWe identified 30,406 rTKA and rTHA patients from 2008 to 2016 using the National Surgical Quality Improvement Program database. Thirty-day incidences for VTE, DVT, PE, and mortality for each year and the overall study period were calculated. Bivariate and multivariate regressions were performed using patient demographics and comorbidities to assess trends in the outcomes of interest.ResultsThe overall incidences of 30-day VTE, DVT, PE, and mortality for rTKA were 1.2%, 0.9%, 0.4%, and 0.5%. Bivariate analysis revealed no significant change over the study period for VTE (P = .137), DVT (P = .406), PE (P = .121; 99% confidence interval 0.112-0.129), and mortality (P = .463). The incidences over the study period of VTE, DVT, PE, and mortality in rTHA were 1.0%, 0.7%, 0.4%, and 0.7%. Bivariate analysis revealed no changes in VTE (P = .393), DVT (P = .376), and PE (P = .602). However, bivariate analysis revealed significant decrease in mortality (P = .010) over the study period.ConclusionWithin 30 days of surgery, approximately 1 in 83 rTKA patients and 1 in 100 rTHA patients experienced a VTE. Furthermore, the rates of VTE remained largely unchanged from 2008 to 2016. Further research regarding the optimal individualized prophylaxis algorithm in rTKA and rTHA is warranted to prevent this complication. This study represents the first investigation of thromboembolic events in rTHA and rTKA.     

Venous Thromboembolism Prophylaxis after Head and Spinal Trauma: Intermittent Pneumatic Compression Devices Versus Low Molecular Weight Heparin

Although there are alternative methods and drugs for preventing venous thromboembolism (VTE), it is not clear which modality is most suitable and efficacious for patients with severe (stable or unstable) head/spinal injures. The aim of this study was to compare intermittent pneumatic compression devices (IPC) with low-molecular-weight heparin (LMWH) for preventing VTE. We prospectively randomized 120 head/spinal traumatized patients for comparison of IPC with LMWH as a prophylaxis modality against VTE. Venous duplex color-flow Doppler sonography of the lower extremities was performed each week of hospitalization and 1 week after discharge. When there was a suspicion of pulmonary embolism (PE), patients were evaluated with spiral computed tomography. Patients were analyzed for demographic features, injury severity scores, associated injuries, type of head/spinal trauma, complications, transfusion, and incidence of deep venous thrombosis (DVT) and PE. Two patients (3.33%) from the IPC group and 4 patients (6.66%) from the LMWH group died, with their deaths due to PE. Nine other patients also succumbed, unrelated to PE. DVT developed in 4 patients (6.66%) in the IPC group and in 3 patients (5%) in the LMWH group. There was no statistically significant difference regarding a reduction in DVT, PE, or mortality between groups (p = 0.04, p > 0.05, p > 0.05, respectively). IPC can be used safely for prophylaxis of VTE in head/spinal trauma patients.     

Symptomatic venous thromboembolism following a hip fracture

Background and purpose Venous thromboembolism (VTE) remains a substantial cause of morbidity and mortality following hip fracture. Previous work has not identified any risk factors associated with the type of hip fracture. We report the incidence of and risk factors for development of symptomatic VTE in patients following a hip fracture.

Patients and methods In this prospective study, we collected information on 5,300 consecutive patients who were admitted to a single unit with a hip fracture—in terms of their pre-admission status, details of any operation performed, and details of complications in the form of symptomatic venous thromboembolism. All patients received thromboprophylaxis with heparin.

Results The incidence of symptomatic VTE was 2.2% (95% CI: 1.8–2.6). 85% of these events occurred within 5 weeks of the fracture. The statistically significant risk factors for symptomatic VTE were better preoperative mobility, living in one's own home, high mental test score, high preoperative hemoglobin, inter-trochanteric fractures, and fixation with a dynamic hip screw. In multivariate analysis adjusting for sex and age, type of residence on admission, type of fracture, and hemoglobin values on admission remained independently significant.

Interpretation We found that the rate of symptomatic VTE using thromboprophylaxis with heparin was low but that there were a number of groups that were at a significantly higher risk of developing VTE. The patients who are particularly at risk appear to be those with a subtrochanteric or intertrochanteric hip fracture; here, the incidence of symptomatic VTE was twice that of intracapsular hip fractures.     

Incidence of venous thromboembolism in elective foot and ankle surgery with and without aspirin prophylaxis

The incidence of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is thought to be low following foot and ankle surgery, but the routine use of chemoprophylaxis remains controversial. This retrospective study assessed the incidence of symptomatic venous thromboembolic (VTE) complications following a consecutive series of 2654 patients undergoing elective foot and ankle surgery. A total of 1078 patients received 75 mg aspirin as routine thromboprophylaxis between 2003 and 2006 and 1576 patients received no form of chemical thromboprophylaxis between 2007 and 2010. The overall incidence of VTE was 0.42% (DVT, 0.27%; PE, 0.15%) with 27 patients lost to follow-up. If these were included to create a worst case scenario, the overall VTE rate was 1.43%. There was no apparent protective effect against VTE by using aspirin. We conclude that the incidence of VTE following foot and ankle surgery is very low and routine use of chemoprophylaxis does not appear necessary for patients who are not in the high risk group for VTE.     

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).

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

BackgroundIt is not clear how to treat asymptomatic deep venous thromboses (DVTs) following elective hip arthroplasty because the natural course of DVTs is unclear. It is therefore valuable to understand the natural course of DVTs and their relation to thromboprophylactic methods.MethodsWe followed 742 consecutive patients who underwent elective hip arthroplasty followed by mechanical or chemical prophylaxis of a DVT. All patients underwent preoperative and postoperative duplex ultrasonography of both limbs. Patients who developed postoperative DVT in the popliteal or calf vein were followed without thromboprophylaxis. DVT-positive patients were prospectively followed up with duplex ultrasonography at 3, 6, 12, and 24 months postoperatively.ResultsIncidences of preoperative and postoperative DVTs were 3.9% and 33.0%, respectively. Nonfatal pulmonary embolism (PE) occurred in 1 patient after negative echography. All DVTs that developed in the calf vein postoperatively and without anticoagulation remained benign, and 93% of the DVTs ultimately disappeared.ConclusionThese results confirmed that the natural course of asymptomatic distal DVTs is benign, with no risk of leading to PE. Thus, distal DVTs could be allowed to remain untreated without chemical prophylaxis to prevent PE in Asian populations.     

Prevention and treatment of deep venous thrombosis

Postoperative venous thromboembolism (VTE) is a common cause of preventable patient morbidity and mortality. Hospitalized patients have multiple risk factors for VTE, which can exert a cumulative effect on the individual patient. Although effective thromboprophylactic measures are currently available, they are not commonly used for a number of reasons, in addition to heightened concern about increasing bleeding risk. Limited data are available characterizing the incidence of symptomatic VTE following major vascular surgery in the absence of thromboprophylactic therapy. Reported rates vary according to the type of surgery, type of prophylaxis used, and diagnostic modalities used for deep venous thrombosis (DVT) and pulmonary embolism (PE). Hospital-acquired DVT in the absence of thromboprophylaxis can occur in up to 40% of patients, occurring primarily in the proximal deep veins, which elevates the risk of PE. Risk factors for VTE in vascular surgery include limb ischemia, prolonged surgery duration, localized intraoperative trauma, and atherosclerosis. Advanced patient age is also a risk factor for VTE; however, the relationship between age and risk of VTE after surgery is complex and dependent on both the type of surgery and the underlying disease process. Evidence-based guidelines for venous thrombo-prophylaxis are now available; however, adoption of and compliance with these guidelines have lagged. Effective thrombo-prophylactic strategies exist and include both pharmacologic and nonpharmacologic approaches. For those surgical patients who develop a VTE, antithrombotic therapy remains the treatment of choice.