Prolonged Thromboprophylaxis Following Hip Replacement Surgery – Results of a Double-blind, Prospective, Randomised, Placebo-controlled Study with Dalteparin (Fragmin®)

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.

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.

The Effect of Sequential Compression Devices on Fibrinolysis in Plastic Surgery Outpatients: A Randomized Trial

BACKGROUND

Sequential compression devices are often considered a mainstay of prophylaxis against deep venous thromboses in surgical patients. The devices are believed to produce a milking action on the deep veins to prevent venous stasis. A systemic fibrinolytic effect has also been proposed, adding a second mechanism of action. The plasma levels of tissue plasminogen activator and plasminogen activator inhibitor-1 reflect fibrinolytic activity.

METHODS

A randomized trial was conducted among 50 consecutive plastic surgery outpatients undergoing cosmetic surgery performed by the author under total intravenous anesthesia and without paralysis. Patients were randomized to receive calf-length sequential compression devices or no sequential compression devices during surgery. Blood samples were obtained from the upper extremity preoperatively and at hourly intervals until the patient was discharged from the postanesthesia care unit. Tissue plasminogen activator and plasminogen activator inhibitor-1 levels were measured. Ultrasound surveillance was used in all patients. There was no outside funding for the study.

RESULTS

All patients agreed to participate (inclusion rate, 100 percent). No patient developed clinical signs or ultrasound evidence of a deep venous thrombosis. There were no significant changes in tissue plasminogen activator levels or plasminogen activator inhibitor-1 levels from the preoperative measurements at any hourly interval and no differences in levels comparing patients treated with or without sequential compression devices.

CONCLUSIONS

No significant change in systemic fibrinolytic activity occurs during outpatient plastic surgery under total intravenous anesthesia. Sequential compression devices do not affect tissue plasminogen activator or plasminogen activator inhibitor-1 levels, suggesting no fibrinolytic benefit.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, I.

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.

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.

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.

The Expanding Role of Diagnostic Ultrasound in Plastic Surgery

Supplemental Digital Content is available in the text.

Background:

Ultrasound in plastic surgery is quickly finding new applications. Ultrasound surveillance may replace ineffective individual risk stratification and chemoprophylaxis for deep venous thromboses. Abdominal penetration can be a catastrophic complication of liposuction. Preoperative screening for fascial defects may reduce risk. Limiting buttock fat injections to the subcutaneous plane is critical for patient safety, but it is difficult to know one’s injection plane.

Methods:

The author’s use of diagnostic ultrasound was evaluated from May 2017 to May 2018. Ultrasound scans were used routinely to detect deep venous thromboses. Patients undergoing abdominal liposuction and/or abdominoplasty were scanned for possible hernias. Other common applications included the evaluation of breast implants, breast masses, and seroma management. The device was used in surgery in 3 patients to assess the plane of buttock fat injection.

Results:

One thousand ultrasound scans were performed during the 1-year study period. A distal deep venous thrombosis was detected in 2 patients. In both cases, the thrombosis resolved within 1 month, confirmed by follow-up ultrasound scans. A lateral (tangential) fat injection method was shown to safely deposit fat above the gluteus maximus fascia.

Conclusions:

Ultrasound scans are highly accurate, noninvasive, and well-tolerated by patients. Some of these applications are likely to improve patient safety. Early detection of deep venous thromboses is possible. Unnecessary anticoagulation may be avoided. Subclinical abdominal defects may be detected. Ultrasound may be used in the office to evaluate breast implants, masses, and seromas. In surgery, this device confirms the level of buttock fat injection.

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.

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.

Pulmonary Embolism Rates Following Total Hip Arthroplasty With Prophylactic Anticoagulation: Some Pulmonary Emboli Cannot Be Avoided

BACKGROUND

A symptomatic pulmonary embolism (PE) after total joint arthroplasty has been described as a "never event." Despite potent anticoagulants and improvements in patient care, PE continues to occur following total hip arthroplasty (THA). This study evaluates symptomatic PE rates over time in THA patients enrolled in multicenter randomized clinical trials (RCTs) assessing the efficacy of venous thromboembolism prophylaxis regimens.

METHODS

The MEDLINE and Cochrane Central Register of Controlled Trials were searched to identify clinical trials assessing prophylactic anticoagulation in patients undergoing THA between January 1995 and December 2015. Inclusion criteria consisted of RCTs evaluating prophylactic anticoagulation in patients undergoing THA. A random effect model was used to combine PE rates across studies.

RESULTS

A total of 21 studies (34,764 patients) were included. Patients were administered low molecular weight heparin (13,590 patients), oral factor Xa inhibitors (6609 patients), oral direct thrombin inhibitors (5965 patients), indirect factors Xa/IIa inhibitors (3444 patients), aspirin (2427 patients), and warfarin (489 patients). Mobile compression was used in 199 patients, and placebo was used in 2041 patients. Across all included studies, the estimated PE rate was 0.21% (95% confidence interval: 0.13%, 0.32%). Between 1997 and 2013, the proportion of PEs did not change in regression analysis.

CONCLUSION

Although the PE rate was low, it was consistent throughout the 17 years spanning these RCTs, which excluded patients with significant morbidity. These results suggest that even healthy THA patients receiving aggressive anticoagulation still have a risk for PE, and the "never event" designation requires reassessment.

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.

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.

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.

Comparative study of extended versus short term thromboprophylaxis in patients undergoing elective total hip and knee arthroplasty in Indian population

BACKGROUND

Postoperative thromboprophylaxis with low molecular weight heparin (LMWH) for an extended period of 4 weeks is now preferred over short term thromboprophylaxis in patients undergoing total hip/knee arthroplasty (THA/TKA). However, most of the data demonstrating the efficacy and safety of extended thromboprophylaxis and short term thromboprophylaxis is from clinical trials done in the West. In India, the data of the incidence of venous thromboembolism (VTE) following THA/TKA has been conflicting and the duration has not been clearly defined. The aim of the study was to evaluate and compare the efficacy of extended thromboprophylaxis over short term thromboprophylaxis in Indian patients undergoing elective THA/TKA surgeries.

MATERIALS AND METHODS

A prospective arm of 197 consecutive patients undergoing elective THA/TKA surgeries who were administered extended thromboprophylaxis for 4 weeks was compared with a historical group of 795 patients who were administered short term thromboprophylaxis for only 7-11 days. In both groups, LMWH (enoxaparin) was used in a dose of 40 mg subcutaneously, in addition to mechanical thromboprophylaxis. Primary efficacy endpoint was objectively confirmed venous thromboembolism (VTE). The presence of DVT was confirmed by a combination of pretest scoring, D-dimer, and Color Doppler Flow Imaging (CDFI) of deep veins of the legs, and pulmonary thromboembolism (PTE) was confirmed by ventilation perfusion (V/Q) scan or pulmonary angiography. Fisher's exact test and t test were used for the statistical analysis. The baseline confounding factors were compared between the two groups using t test for comparing the means for continuous data and Fisher's exact test for categorical data.

RESULTS

In the prospective arm, only 1 patient developed symptomatic PTE compared to 26 (3.27%) cases of VTE (20 cases of PTE and 6 cases of DVT) in the retrospective group.

CONCLUSION

Extended thromboprophylaxis (for 4 weeks) was found to be more effective than short term thromboprophylaxis in minimizing the risk of postoperative VTE in patients who underwent THA/TKA.

Relevance of immobility and importance of risk assessment management for medically ill patients

Recent or continued immobility is a significant risk factor for venous thromboembolism (VTE) in acutely ill medical patients. Patients may benefit from thromboprophylaxis; however, its optimal duration remains unclear. The Extended Clinical Prophylaxis in Acutely Ill Medical Patients (EXCLAIM) study was the first trial to systematically investigate how the degree of immobilization relates to the risk of developing VTE. EXCLAIM offers insights into the duration of VTE risk associated with reduced mobility and helps identify which patients would benefit most from extended-duration thromboprophylaxis. Further recent studies suggest that extended-duration thromboprophylaxis may be in order in certain high-risk patients to protect the patients from the risk of VTE events occurring, particularly in the posthospitalization period. Baseline d-dimer data and level of mobility could be included in risk assessment. Physicians are recommended to consider the use of extended-duration thromboprophylaxis based on individual risk assessment management (RAM) and balance of benefit and harm.

Comprehensive assessment of prophylactic preoperative inferior vena cava filters for major spinal reconstruction in adults

STUDY DESIGN

A retrospective data analysis.

OBJECTIVE

To report a comprehensive assessment of preoperative prophylactic inferior vena cava (IVC) filter placement in spine surgery.

SUMMARY OF BACKGROUND DATA

Venous thromboembolism (VTE) is a serious complication after major spinal reconstructive surgery in adults. Specifically, pulmonary embolism (PE) can result in significant morbidity and mortality, and it has been reported in up to 13% of patients. Prophylactic IVC filter placement was initiated for all "high-risk" spinal surgery patients after a pilot study demonstrated decreased VTE-related morbidity and mortality.

METHODS

After institutional review board approval, the medical records of all patients receiving an IVC filter at a single institution from 2000 to 2007 were reviewed. Age, sex, surgical approach, postoperative deep vein thrombosis (DVT), postoperative superficial thrombus, presence of pulmonary or paradoxical embolus, mortality, and IVC filter complications were all evaluated. Indications for IVC filter placement included history of DVT or PE, malignancy, hypercoagulability, prolonged immobilization, staged procedures of longer than 5 segment levels, combined anterior-posterior approaches, iliocaval manipulation during exposure, and anesthetic time of more than 8 hours. Descriptive statistics were used for the analysis of patient characteristics. Nonparametric frequency statistics (odds ratios [OR], χ) were used for analysis of main outcomes.

RESULTS

A total of 219 patients (150 women, 69 men) with a mean age of 58.8 (range, 17-86) years, were analyzed. There were 2 complications from IVC filter placement (66 Greenfield filters; 157 retrievable filters). The incidence of lower extremity DVT was 18.7% (41/219) in 36 patients. PE incidence was 3.7% (8/219 patients), and the paradoxical embolus rate was 0.5% (1 patient). Prophylactic IVC filter use reduced the odds of developing a pulmonary embolus (OR = 3.7, P < 0.05) compared with population controls. Patients receiving Greenfield filters had significantly higher VTE incidence than those receiving retrievable filters (OR = 2.8, P = 0.008). Anesthesia duration of more than 8 hours significantly increases VTE incidence (P = 0.029). No statistical significance (P < 0.05) was noted with combined anterior-posterior approach (118 patients) versus posterior-only approach (101 patients) and the incidence of DVT (24/118, 20.3% for former; 17/101, 16.8% for latter). There were a total of 14 deaths; none related to PE or paradoxical embolism during an 8-year period. Mean and median follow-up was 2.8 and 2.4 years, respectively, with 126 achieving 2 or more years of follow-up.

CONCLUSION

VTE-related morbidity and mortality have heightened the awareness within the spine community to the perioperative management of patients undergoing major spinal reconstruction. Prophylactic IVC filter placement significantly lowers VTE-related events, including PE development, than population controls.

A pilot study of computed tomography-detected asymptomatic pulmonary filling defects after hip and knee arthroplasties

We asked what the incidence of asymptomatic filling defects is on routine multidetector computed tomography (MDCT) in primary hip (total hip arthroplasty [THA]) and knee arthroplasties (TKA) patients. We prospectively performed MDCT scans on the first postoperative day for THA (n = 21)/TKA (n = 27). Patients underwent routine postoperative care, and data were collected for symptoms such as tachycardia or shortness of breath. More patients undergoing TKA had positive computed tomography scans than those undergoing THA: 11 (41%) vs 1 (5%), respectively. All patients diagnosed with a filling defect were discharged from the hospital without treatment of symptomatic pulmonary embolism. Our study demonstrates a high rate of abnormal MDCT early after lower extremity arthroplasty, the clinical importance of which may be benign.

Prevention of VTE in orthopedic surgery patients: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

VTE is a serious, but decreasing complication following major orthopedic surgery. This guideline focuses on optimal prophylaxis to reduce postoperative pulmonary embolism and DVT.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

In patients undergoing major orthopedic surgery, we recommend the use of one of the following rather than no antithrombotic prophylaxis: low-molecular-weight heparin; fondaparinux; dabigatran, apixaban, rivaroxaban (total hip arthroplasty or total knee arthroplasty but not hip fracture surgery); low-dose unfractionated heparin; adjusted-dose vitamin K antagonist; aspirin (all Grade 1B); or an intermittent pneumatic compression device (IPCD) (Grade 1C) for a minimum of 10 to 14 days. We suggest the use of low-molecular-weight heparin in preference to the other agents we have recommended as alternatives (Grade 2C/2B), and in patients receiving pharmacologic prophylaxis, we suggest adding an IPCD during the hospital stay (Grade 2C). We suggest extending thromboprophylaxis for up to 35 days (Grade 2B). In patients at increased bleeding risk, we suggest an IPCD or no prophylaxis (Grade 2C). In patients who decline injections, we recommend using apixaban or dabigatran (all Grade 1B). We suggest against using inferior vena cava filter placement for primary prevention in patients with contraindications to both pharmacologic and mechanical thromboprophylaxis (Grade 2C). We recommend against Doppler (or duplex) ultrasonography screening before hospital discharge (Grade 1B). For patients with isolated lower-extremity injuries requiring leg immobilization, we suggest no thromboprophylaxis (Grade 2B). For patients undergoing knee arthroscopy without a history of VTE, we suggest no thromboprophylaxis (Grade 2B).

CONCLUSIONS

Optimal strategies for thromboprophylaxis after major orthopedic surgery include pharmacologic and mechanical approaches.

Risk of postoperative venous thromboembolism in Indian patients sustaining pelvi-acetabular injury

Most surgeons believe that Asians have a low risk of developing venous thromboembolism (VTE) and routine thromboprophylaxis therapy is not required after major orthopaedic trauma. This study evaluates the postoperative risk of VTE in Indian patients sustaining pelvi-acetabular injury. Fifty-six patients with pelvi-acetabular injury, who underwent open reduction and internal fixation, were prospectively evaluated for VTE in the postoperative period. They were evaluated, both clinically and radiologically (pulmonary CT angiography and indirect venography of lower limb and pelvis veins), until six weeks after surgery. A total of 16 patients developed VTE, of which 12 had proximal deep vein thrombosis (DVT), ten had pulmonary embolism (PE) and only two had distal DVT. Six patients with proximal DVT had associated PE. The risk of development of VTE among Indian patients after pelvi-acetabular injury is high (28.6%) with increasing chances of proximal DVT and PE; hence, administration of routine thromboprophylaxis is fully justified in them.

Retrospective administrative database study of the time period of venous thromboembolism risk during and following hospitalization for major orthopedic or abdominal surgery in real-world US patients

PURPOSE

To assess the incidence and time course of symptomatic venous thromboembolism (VTE) events in patients during and following hospitalization for major orthopedic or abdominal surgery.

METHODS

Data were extracted from the Thomson Reuters MarketScan(®) Inpatient Drug Link File for surgical patients admitted between January 2005 and December 2008. The analysis included 8989 abdominal surgery patients and 4220 orthopedic surgery patients. The cumulative risks of VTE and VTE hazard were assessed over a 180-day evaluation period after the hospital admission date, using Kaplan-Meier analysis and LOESS regression, respectively.

RESULTS

In total, 305 (2.3%) patients experienced a symptomatic VTE event. These were most frequent during days 1-9 (78 events) and 10-19 (72 events). In all, 64% of events occurred after discharge. Venous thromboembolism hazard peaked at approximately 1.3 per 1000 person-days (day 8) following orthopedic surgery and at approximately 0.52 per 1000 person-days (day 11) following abdominal surgery. In-hospital pharmacologic prophylaxis was received by 88.3% and 30.2% of orthopedic and abdominal surgery patients, respectively, whereas pharmacologic prophylaxis following hospitalization was received by 41.3% and 3.0% of patients, respectively.

CONCLUSIONS

The time course of VTE in major surgery patients suggests that VTE risk is highest during the first 19 days after admission and that considerable VTE risk extends into the period after discharge.

Incidence and time course of asymptomatic deep vein thrombosis with fondaparinux in patients undergoing total joint arthroplasty

INTRODUCTION

There are many reports concerning fondaparinux prophylaxis of asymptomatic deep vein thrombosis (DVT) after total hip arthroplasty (THA) or total knee arthroplasty (TKA), but little is known about the time course of aymptomatic DVT development during the administration of fondaparinux. The aim of the present study was to define the incidence and time course of aymptomatic DVT development during administration of fondaparinux, and to assess the efficacy of fondaparinux in resolving DVT.

MATERIALS AND METHODS

We studied consecutive 71 patients who underwent THA surgery, and 30 patients who underwent TKA surgery with fondaparinux prophylaxis. Patients received once-daily subcutaneous injections of 2.5mg of fondaparinux for 14 days after surgery. DVT was diagnosed by ultrasonography, and it was scheduled on the day of surgery on day 1, day 4, and day 14 after surgery.

RESULTS

In patients who received fondaparinux for 14 days after THA surgery, the incidence of DVT was 0% on the day of the surgery, 13.6% at day 1, 27.1% at day 4, and 11.9% at day 14. In patients who received fondaparinux for 14 days after TKA surgery, the incidence of DVT was 4.2% on the day after surgery, 50.0% at day 1, 58.3% at day 4, and 20.8% at day 14. The incidence of DVT after THA or TKA surgery at day 14 was significantly reduced compared to that at day 4.

CONCLUSION

The incidence of asymptomatic DVT up to day 4 was high, but with 14 days continued treatment of fondaparinux, the incidence of asymptomatic DVT occurring at postoperative day 4 was significantly reduced at day 14.

Review article: thromboprophylaxis after total hip replacement

The risk of secondary haematologic complications such as deep vein thrombosis or pulmonary embolism increases significantly when a transient period of hypercoagulability is induced after total hip replacement (THR). A number of drug-based anticoagulant approaches are available to modulate this risk, but the optimal length of therapy for such approaches remains unclear. The literature was reviewed for evidence-based support of the routine use of an extended course (>14 days) of thromboprophylaxis after THR. Electronic databases and real-time online literature searches were performed, using the PubMed (Medline), EMBASE, CINAHL and GoogleScholar, and the Cochrane and British Medical Journal Clinical Evidence libraries. Author-defined key word searches were performed. Only articles in the English language, for which full text could be retrieved, were reviewed. There is robust evidence to support an extended course (>14 days) of thromboprophylaxis after THR. Such recommendations have been translated into the guidelines of key professional bodies, including those of the American College of Chest Physicians. Meta-review suggests a clear benefit of such regimens and supports wider adoption, even when weighed against a small increase in adverse events.

Need to improve thromboprophylaxis across the continuum of care for surgical patients

INTRODUCTION

Prophylaxis for venous thromboembolism (VTE) is underused following major surgery and frequently stopped at hospital discharge despite short stays and high VTE risk for several weeks postsurgery. We evaluated inpatient and postdischarge prophylaxis in patients who underwent major abdominal or orthopedic surgery.

METHODS

Patient records were assessed for anticoagulant use by cross-matching data from the Premier's Perspective discharge database with the i3/Ingenix LabRx outpatient and inpatient database from January 2005 to December 2007. Abdominal or orthopedic surgery patients at risk of VTE according to the 2004 American College of Chest Physicians guidelines and with no contraindications to anticoagulation were included.

RESULTS

A total of 14,009 eligible surgical discharges were analyzed. Only 27.9% of the 10,698 abdominal surgery patients received anticoagulation in hospital. Most inpatients received unfractionated heparin (12.3% of the total abdominal surgery population) or enoxaparin (11.8%). Of the 3311 orthopedic surgery patients, 91.1% received in-hospital anticoagulation. Similar proportions of patients received enoxaparin (32.1%), warfarin (31.1%), or other agents (28.0%). Only 1.2% of abdominal surgery patients had an anticoagulant prescription filled 30 days postdischarge. Although orthopedic surgery outpatients had higher anticoagulation rates, only 54.4% had filled a prescription 30 days postdischarge with 31.1% receiving warfarin, 18.5% receiving enoxaparin, and 4.8% receiving other anticoagulants. The higher prophylaxis rate in orthopedic patients may reflect the high VTE risk in orthopedic surgery patients and increased awareness among orthopedic surgeons.

CONCLUSION

This real-world study highlights the underuse of thromboprophylaxis in hospitalized surgical patients, especially following abdominal surgery. Furthermore, a considerable proportion of these patients do not receive postdischarge anticoagulation despite guideline recommendations. Further efforts are needed to improve anticoagulant use, particularly in the outpatient setting.

Venous thromboembolism in Korean patients undergoing major orthopedic surgery: a prospective observational study using computed tomographic (CT) pulmonary angiography and indirect CT venography

In patients undergoing major orthopedic surgery, data of deep venous thrombosis (DVT) and pulmonary embolism (PE) are lacking as studied by computed tomographic (CT) pulmonary angiography and indirect CT venography (CTPA-CTV). A prospective observational study was performed for 363 Korean patients undergoing major orthopedic surgery to determine the incidence of venous thromboembolism (VTE), especially proximal DVT and PE. The incidence of VTE was 16.3% (n=59). Of them, 8 patients (2.2%) were symptomatic. The rate of VTE was the highest in patients who underwent total knee replacement (40.4%), followed by hip fracture surgery (16.4%), and total hip replacement (8.7%; P<0.001). The incidence of PE was 6.6% (n=24). Of them, 4 patients (1.1%) were symptomatic. Forty-one patients (11.3%) were in the proximal DVT or PE group. Based on multivariate analysis, total knee replacement and age > or =65 yr were significant risk factors for proximal DVT or PE in patients undergoing major orthopedic surgery (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.1-5.1; P=0.025; and OR, 2.1; 95% CI, 1.0-4.4; P=0.046, respectively). Taken together, the overall incidence of PE was 6.6% and rate of symptomatic PE rate was 1.1%. Knee joint replacement and age > or =65 yr were significant risk factors for proximal DVT or PE.

Cost effectiveness of venous thromboembolism pharmacological prophylaxis in total hip and knee replacement: a systematic review

Total hip and knee replacements (THR and TKR) are high-risk settings for venous thromboembolism (VTE). This review summarizes the cost effectiveness of VTE prophylaxis regimens for THR and TKR. We searched MEDLINE (January 1997 to October 2009), EMBASE (January 1997 to June 2009) and the UK NHS Economic Evaluation Database (1997 to October 2009). We analysed recent cost-effectiveness studies examining five categories of comparisons: (i) anticoagulants (warfarin, low-molecular-weight heparin [LMWH] or fondaparinux) versus acetylsalicylic acid (aspirin); (ii) LMWH versus warfarin; (iii) fondaparinux versus LMWH; (iv) comparisons with new oral anticoagulants; and (v) extended-duration (> or =3 weeks) versus short-duration (<3 weeks) prophylaxis. We abstracted information on cost and effectiveness for each prophylaxis regimen in order to calculate an incremental cost-effectiveness ratio. Because of variations in effectiveness units reported and horizon length analysed, we calculated two cost-effectiveness ratios, one for the number of symptomatic VTE events avoided at 90 days and the other for QALYs at the 1-year mark or beyond. Our search identified 33 studies with 67 comparisons. After standardization, comparisons between LMWH and warfarin were inconclusive, whereas fondaparinux dominated LMWH in nearly every comparison. The latter results were derived from radiographic VTE rates. Extended-duration prophylaxis after THR was generally cost effective. Small numbers prohibit conclusions about aspirin, new oral anticoagulants or extended-duration prophylaxis after TKR. Fondaparinux after both THR and TKR and extended-duration LMWH after THR appear to be cost-effective prophylaxis regimens. Small numbers for other comparisons and absence of trials reporting symptomatic endpoints prohibit comprehensive conclusions.

The ''critical thrombosis period'' in major orthopedic surgery: when to start and when to stop prophylaxis

Patients undergoing major orthopedic surgery are at high venous thromboembolism (VTE) risk, with morbid and potentially fatal consequences. Anticoagulant VTE prophylaxis reduces rates of postoperative deep vein thrombosis by up to 60% to 70% in these patients. Therefore, pharmacological prophylaxis with low-molecular-weight heparins (LMWHs), vitamin K antagonists, or fondaparinux is recommended by current guidelines. However, there remains an ongoing debate regarding when to initiate and the optimal duration for prophylaxis. Here, we discuss the mechanisms underlying thrombus formation in patients undergoing major orthopedic surgery, and we review the current literature on the benefit-to-risk ratio associated with preoperative and postoperative initiation of thromboprophylaxis and also the benefit-to-risk ratio in cases of neuraxial anesthesia. We also discuss the duration of postoperative VTE risk following major orthopedic surgery and assess the ''critical thrombosis period'' when prophylaxis should be provided. Current literature reflects the need to balance the improved efficacy of initiating prophylaxis close to the surgery with increased risk of perioperative bleeding. Evidence from pathology, epidemiology, and clinical studies suggests the risk period for VTE begins at surgery and extends well beyond hospitalization-a crucial issue when considering how long to give prophylaxis-and, in the case of total hip arthroplasty, for at least 3 months after surgery. Literature supports the greater use of ''just-in-time'' thromboprophylaxis initiation and after-discharge continuation of optimal prophylaxis in orthopedic surgery patients. Providing optimal thromboprophylaxis throughout the critical thrombosis period where a patient is at VTE risk will ensure the best reductions in VTE-related morbidity and mortality.

Thrombosis markers in hip versus knee arthroplasty: a pilot study

PURPOSE

To compare the thrombosis markers for thrombosis and fibrinolysis in patients undergoing hip versus knee arthroplasty.

METHODS

Seven women aged 38 to 61 years who underwent total hip arthroplasty (THA) and 7 women aged 57 to 67 years who underwent total knee arthroplasty (TKA) were studied. Thromboprophylaxis was given before and after surgery. In patients undergoing TKA, an automatic pneumatic tourniquet was used. Blood samples were drawn (1) before surgery (control value), (2) at wound closure (immediately before release of the tourniquet in TKA), and (3) 4 hours after surgery. Thrombosis markers (prothrombin fragment 1.2 [F1.2], plasmin/ alpha2-antiplasmin complex [PAP], and D-dimer) of the 2 groups were compared.

RESULTS

The F1.2 level increased significantly at wound closure and remained elevated 4 hours after surgery in the THA group, whereas it was unchanged at wound closure but increased significantly 4 hours after surgery in the TKA group. The PAP level was constant peri- and post-operatively in the THA group, whereas it increased significantly 4 hours after surgery in the TKA group. The D-dimer level increased significantly at wound closure and 4 hours after surgery in the THA group, whereas it was unchanged at wound closure but increased significantly 4 hours after surgery in the TKA group.

CONCLUSION

Systemic thrombin generation starts perioperatively in THA and after tourniquet deflation in TKA, indicating that wound blood must reach the systemic circulation to activate the relevant mediators.

Cost-effectiveness of prolonged thromboprophylaxis after cancer surgery

BACKGROUND

Consensus guidelines recommend prolonged thromboprophylaxis for up to 4 weeks after major abdominopelvic cancer operations. Several factors impede widespread adoption of these guidelines. These include lack of awareness, cost, increased bleeding complications, increased incidence of heparin-induced thrombocytopenia, and poor patient compliance.

METHODS

A cost-effectiveness model was constructed comparing four potential strategies to postdischarge thromboprophylaxis in surgical oncology patients: (1) low-molecular-weight heparin (LMWH) once daily; (2) low-dose unfractionated heparin (LDUH) three times daily; (3) oral aspirin once daily; or (4) no prolonged prophylaxis. Probabilities and costs were estimated on the basis of published literature and average Medicare reimbursement. The decision analysis was conducted from the perspective of the health care system, with the primary end point being cost per patient without venous thromboembolism (VTE). Sensitivity analyses tested the robustness of the results.

RESULTS

LDUH was most cost-effective, saving $154 per patient without VTE compared with no prophylaxis. LMWH was not cost-effective, incurring a cost of $230 per patient without VTE compared with no prophylaxis. Aspirin was a viable alternative to LDUH, saving $123 compared with no prophylaxis. When poor compliance was considered, aspirin became the dominant strategy. Sensitivity analyses failed to show any instance where LMWH was cost-effective. In terms of population costs, widespread use of LDUH after discharge would save $30.3 million per year in the United States.

CONCLUSIONS

Although all chemical prophylaxis is effective in preventing VTE in the outpatient setting after cancer surgery, either LDUH or aspirin are the most cost-effective, depending on patient compliance.

Overview of current venous thromboembolism protocols in hip reconstruction

Venous thromboembolic disease continues to be a serious complication of total-hip arthroplasty. The use of anticoagulant drugs for preventing this complication has repeatedly been proven to be useful. This article reviews the current evidence-based recommendations for anticoagulant prophylaxis after total-hip arthroplasty and provides insight into the current areas of active research and controversy.

[Thromboembolic disease in orthopedic surgery]

Thromboembolic complications are frequent after orthopaedic surgery of the limbs. Strategies to minimize these complications go from recognize the risk factors of the patient to introduce new antithrombotic drugs, and including general medical care, regional anaesthesia and early mobilization. Based in epidemiological studies, prophylaxis must be extended 4-6 weeks in total hip and knee arthroplasty and in surgery of the hip fracture.

Time course of thrombosis and fibrinolysis in total knee arthroplasty with tourniquet application. Local versus systemic activations

BACKGROUND

Venous thrombosis is common in knee surgery, and it has been assumed that vein occlusion by tourniquet in itself may induce thrombogenic and fibrinolytic activity. Prophylactic treatment is used up to 12 h before or after surgery, and recent clinical trials suggest that the timing of initiating prophylaxis significantly influences antithrombotic effectiveness.

MATERIALS AND METHODS

We studied the time course of coagulation and fibrinolysis locally and systemically during total knee arthroplasty. Specific markers of thrombosis (prothrombin fragment 1.2 (F1.2)) and fibrinolysis (plasmin-antiplasmin (PAP) and D-dimer) were examined in seven female and two male patients.

RESULTS

There were no systemic activations of either F1.2 (P = 0.314), PAP (P = 0.314) or D-dimer (P = 0.600) during surgery or at 10 min postoperatively (P = 0.139, 0.139 and 0.128, respectively) as compared to baseline data. At 4 h postoperatively there were significant increments in levels of F1.2 (P = 0.008), PAP (P = 0.038) and D-dimer (P = 0.046). With tourniquet deflation the values of F1.2, PAP and D-dimer were significantly higher in the tourniquet limb than the in the contra lateral limb (P = 0.025, 0.012 and 0.028, respectively). At 10 min after tourniquet deflation, the differences in F1.2, PAP and D-dimer between the two limbs were not significant.

CONCLUSION

The use of tourniquet in total knee arthroplasty causes local thrombogenic and fibrinolytic activity, but without influences in the systemic circulation. Systemic activations in thrombosis and fibrinolysis start when local mediators from the injured limb are released after tourniquet deflation.

Extended duration rivaroxaban versus short-term enoxaparin for the prevention of venous thromboembolism after total hip arthroplasty: a double-blind, randomised controlled trial

BACKGROUND

The risk of venous thromboembolism is high after total hip arthroplasty and could persist after hospital discharge. Our aim was to compare the use of rivaroxaban for extended thromboprophylaxis with short-term thromboprophylaxis with enoxaparin.

METHODS

2509 patients scheduled to undergo elective total hip arthroplasty were randomly assigned, stratified according to centre, with a computer-generated randomisation code, to receive oral rivaroxaban 10 mg once daily for 31-39 days (with placebo injection for 10-14 days; n=1252), or enoxaparin 40 mg once daily subcutaneously for 10-14 days (with placebo tablet for 31-39 days; n=1257). The primary efficacy outcome was the composite of deep-vein thrombosis (symptomatic or asymptomatic detected by mandatory, bilateral venography), non-fatal pulmonary embolism, and all-cause mortality up to day 30-42. Analyses were done in the modified intention-to-treat population, which consisted of all patients who had received at least one dose of study medication, had undergone planned surgery, and had adequate assessment of thromboembolism. This study is registered at ClinicalTrials.gov, number NCT00332020.

FINDINGS

The modified intention-to-treat population for the analysis of the primary efficacy outcome consisted of 864 patients in the rivaroxaban group and 869 in the enoxaparin group. The primary outcome occurred in 17 (2.0%) patients in the rivaroxaban group, compared with 81 (9.3%) in the enoxaparin group (absolute risk reduction 7.3%, 95% CI 5.2-9.4; p<0.0001). The incidence of any on-treatment bleeding was much the same in both groups (81 [6.6%] events in 1228 patients in the rivaroxaban safety population vs 68 [5.5%] of 1229 patients in the enoxaparin safety population; p=0.25).

INTERPRETATION

Extended thromboprophylaxis with rivaroxaban was significantly more effective than short-term enoxaparin plus placebo for the prevention of venous thromboembolism, including symptomatic events, in patients undergoing total hip arthroplasty.

Global Risk Profile Verification in Patients with Venous Thromboembolism (GRIP VTE) in 5 Gulf Countries

Background: The Global Risk Profile Verification in Patients with Venous Thromboembolism was the first prospective multicenter registry conducted in Arabian Gulf countries to explore the epidemiology of venous thromboembolic (VTE) disorders and to provide data on diagnosis and disease management. Methods: Data on 242 patients with confirmed VTE were submitted between September 2003 and November 2003 from 28 contributing hospitals in the Arabian Gulf region. Differences between groups were assessed by the χ2test or Fisher exact test for categorical variables. The Student's t test was used for testing proportions. Results: The frequency of VTE cases is deep vein thrombosis (DVT), 187 (77.27%); pulmonary embolism (PE), 35 (14.46%); and DVT with PE, 20 (8.26%). The most common symptoms of DVT and DVT/PE patients were calf pain (72%), calf swelling (63.8%), and localized tenderness (52.2%). The most common symptoms in patients with PE alone and DVT/PE were dyspnea (83.6%), thoracic pain (69.1%), and cough (40%). Risk factors for VTE were immobilization (41.3%), age >65 years (28.9%), a history of VTE (20.7%), and trauma (19%). Among surgical interventions, orthopedic procedures induced the greatest number of VTE cases, followed by general surgery and gynecological procedures. Low-molecular-weight heparins were chosen to treat 33.7% of DVT cases, whereas unfractionated heparin was used in 21.9% of cases. Conclusion: VTE remains a common problem in medical and surgical patients in the Arabian Gulf states. Recognition of the common risk factors is of extreme importance to implement the appropriate prophylactic strategy according to the published guidelines.

Cost-effectiveness of extended prophylaxis with fondaparinux compared with low molecular weight heparin against venous thromboembolism in patients undergoing hip fracture surgery

A model was developed to estimate costs and clinical effectiveness of fondaparinux compared with enoxaparin after hip fracture surgery in Sweden. Outcomes and costs of venous thromboembolism (VTE)-related care from a health care perspective were incorporated, with symptomatic deep-vein thrombosis and pulmonary embolism, recurrent VTE, post-thrombotic syndrome, major haemorrhage and all-cause death being included. Event probabilities were derived from fondaparinux clinical trial data and published data. VTE-related resource use and associated costs as well as costs of prophylaxis were based on local Swedish data. Extended prophylaxis with fondaparinux could avoid an additional 28 symptomatic VTE per 1,000 patients compared with extended prophylaxis with enoxaparin in hip fracture surgery patients. Although the prophylaxis costs were higher in the fondaparinux group, these were offset by the lower costs associated with treating fewer VTE, which thus indicates that extended fondaparinux prophylaxis is the dominant alternative when compared with enoxaparin in hip fracture surgery.

Post-discharge symptomatic thromboembolic events in hip fracture patients

INTRODUCTION

The aim of this study was to audit referral rates for post-discharge symptomatic thromboembolic events following hip fracture surgery to assess the extent of the clinical problem and to initiate discussion on prolonged chemoprophylaxis.

PATIENTS AND METHODS

All patients who underwent surgery for proximal hip fractures in one year (2001-2002) were followed up. Patient case-notes were used to identify all morbidity episodes within 3 months following discharge. Patients with suspected symptomatic thromboembolic episodes were investigated to confirm the diagnoses objectively. Reasons for hospital readmission and causes of death were identified.

RESULTS

A total of 267 patients who underwent surgery for proximal hip fractures were included in the study. Forty-three patients died during initial admission episode. Of the 224 patients discharged, 46 (20.54%) patients were referred back to hospital within 3 months, for unplanned emergency management. Of these, 8 patients (3.57%) were referred back for suspected thromboembolic events. Of these, 6 (2.67%) were referred with a clinical diagnoses of deep vein thrombosis (DVT) but only 1 patient (0.45%) was confirmed to have DVT. Two patients (0.89%) were referred with features of pulmonary embolism (PE). Both were confirmed on ventilation-perfusion scans and both patients died. One patient died following PE in the community.Thus, overall, 3 deaths (1.34%) following discharge were recorded to be due to pulmonary embolism.

CONCLUSIONS

Suspected thromboembolic events constitute a major proportion of unplanned referrals back to the hospital. Three deaths due to delayed pulmonary embolism may justify prolonged universal chemoprophylaxis following hip fracture surgery.

Low-dose warfarin coupled with lower leg compression is effective prophylaxis against thromboembolic disease after hip arthroplasty

Consecutive patients having elective total hip arthroplasty were prescribed 1 mg of warfarin for 7 days preceding surgery, variable doses while in hospital (target international normalized ratio, 1.5-2.0), and discharged to rehabilitation center or home taking 1 mg daily until 4-week to 6-week follow-up visit. Lower leg pneumatic compression was used postoperatively and elastic compression stockings after discharge. Hospital and clinic charts plus auxiliary sources were reviewed for evidence of thromboembolic diseases (TED). Of 1003 consecutive patients studied, 3 (0.3%, 95% CI 0.0-0.6%) had symptomatic TED, including 2 with deep venous thrombosis and 1 with nonfatal pulmonary embolus. Follow-up rate was 99.1%. Complications from warfarin were minimal. Very-low-dose warfarin coupled with lower leg compression is effective prophylaxis against TED after elective hip arthroplasty when prescribed as described.

The use of graduated compression stockings in association with fondaparinux in surgery of the hip

Little is known about the efficacy of graduated compression stockings in preventing venous thromboembolism after hip surgery. We conducted a prospective, randomised single-blind study to determine whether the addition of compression stockings to fondaparinux conferred any additional benefit.

The study included 874 patients, of whom 795 could be evaluated (400 in the fondaparinux group and 395 in the fondaparinux plus compression stocking group). Fondaparinux was given post-operatively for five to nine days, either alone or combined with wearing stockings, which were worn for a mean 42 days (35 to 49).

The study outcomes were venous thromboembolism, or sudden death before day 42. Duplex ultrasonography was scheduled within a week of day 42. Safety outcomes were bleeding and death from venous thromboembolism.

The prevalence of deep-vein thrombosis was similar in the two groups 5.5% (22 of 400) in the fondaparinux group and 4.8 (19 of 395) in the fondaparinux plus stocking group (odds ratio 0.88, 95% confidence interval 0.46 to 1.65, p = 0.69). Major bleeding occurred in only one patient.

The addition of graduated compression stockings to fondaparinux appears to offer no additional benefit over the use of fondaparinux alone.