Aspirin for the Prophylaxis of Venous Thromboembolic Events in Orthopedic Surgery Patients: A Comparison of the AAOS and ACCP Guidelines with Review of the Evidence

Aspirin versus low-molecular-weight heparin for thromboprophylaxis after orthopaedic surgery: a systematic review and meta-analysis

The article aimed to compare the efficiency and safety of aspirin with low-molecular-weight heparin (LMWH) for thromboprophylaxis in orthopaedic surgery patients. According to the inclusion and exclusion criteria, PubMed, Embase and Cochrane Library database were searched for studies comparing aspirin and LMWH in venous thromboembolism (VTE) prophylaxis until 25 April 2023. The outcome measures included deep venous thrombosis(DVT)/Pulmonary embolism(PE) events, major bleeding events, wound complications, wound infection and death. Six studies met the requirements of our meta-analysis, including 12 470 patients in the aspirin group and 10 857 patients in the LMWH group. The meta-analysis showed that results showed that LMWH was superior to aspirin in preventing VTE events (odds ratio (OR) 1.44, 95% CI 1.24-1.68, P  < 0.00001), whereas there was no significant difference between them in bleeding events (OR 0.95, 95% CI 0.86-1.05, P  = 0.33), wound complication (OR 0.58, 95% CI 0.28-1.17, P  = 0.13), wound infection (OR 1.12, 95% CI 0.86-1.47, P  = 0.39) and mortality (OR 1.04, 95% CI 0.70-1.55, P  = 0.83). In addition, subgroup analysis showed that compared with aspirin, LMWH was more likely to reduce the incidence of DVT events in orthopaedic surgery patients (OR 1.59, 95% CI 1.33-1.91, P  < 0.00001), whereas there was no advantage in reducing the incidence of PE events (OR 1.22, 95% CI 0.62-2.40, P  = 0.56). Despite the similar safety profiles, this meta-analysis showed that LMWH was significantly superior to aspirin in thromboprophylaxis after orthopaedic surgery. LMWH was still the first-line drug for thrombosis prevention in patients who underwent major orthopaedic surgeries.

RANDOMIZED CLINICAL TRIAL OF ASPIRIN AS PROPHYLAXIS FOR THROMBOEMBOLISM IN HIP ARTHROPLASTY

Objective

This study aims to evaluate aspirin as a chemical prophylaxis (200 mg) in total hip arthroplasty.

Methods

the study compared two groups and used ultrasonography (USG) to screen for low-deep venous thrombosis. Group 1 received 600 mg (control), and Group 2 received 200 mg of (intervention), associated with the use of elastic compression stockings and early walking.

Results

fourteen patients were allocated to Group A (200mg), and 16 to Group B (600mg); in group A (200mg), 3 cases with thrombus below the popliteal vein were detected at the first USG examination. All of them are in the left lower limb (21.4%). In group B (600 mg), 5 cases were identified after the first exam (31.2%). All cases were asymptomatic and followed the protocol with prophylaxis only with Aspirin.

Conclusion

In the statistical data, there were no differences in the presence of thrombus between the 200- and 600 mg groups, which is credited to using low-dose aspirin in low doses (200mg). Hematimetric levels returned to baseline levels and suggested there was no chronic or acute bleeding related to the use of aspirin. The manuscript was prepared according to the CONSORT guideline 2010. Level of Evidence I; Longitudinal Randomized Comparative Clinical Study.

Addition of aspirin to venous thromboembolism chemoprophylaxis safely decreases venous thromboembolism rates in trauma patients

Background

Trauma patients exhibit a multifactorial hypercoagulable state and have increased risk of venous thromboembolism (VTE). Despite early and aggressive chemoprophylaxis (CP) with various heparin compounds ("standard" CP; sCP), VTE rates remain high. In high-quality studies, aspirin has been shown to decrease VTE in postoperative elective surgical and orthopedic trauma patients. We hypothesized that inhibiting platelet function with aspirin as an adjunct to sCP would reduce the risk of VTE in trauma patients.

Methods

We performed a retrospective observational study of prospectively collected data from all adult patients admitted to an American College of Surgeons Level I Trauma center from January 2012 to June 2015 to evaluate the addition of aspirin (sCP+A) to sCP regimens for VTE mitigation. Cox proportional hazard models were used to assess the potential benefit of adjunctive aspirin for symptomatic VTE incidence.

Results

10,532 patients, median age 44 (IQR 28 to 62), 68% male, 89% blunt mechanism of injury, with a median Injury Severity Score (ISS) of 12 (IQR 9 to 19), were included in the study. 8646 (82%) of patients received only sCP, whereas 1886 (18%) patients received sCP+A. The sCP+A cohort displayed a higher median ISS compared with sCP (13 vs 11; p<0.01). The overall median time of sCP initiation was hospital day 1 (IQR 0.8 to 2) and the median day for aspirin initiation was hospital day 3 (IQR 1 to 6) for the sCP+A cohort. 353 patients (3.4%) developed symptomatic VTE. Aspirin administration was independently associated with a decreased relative hazard of VTE (HR 0.57; 95% CI 0.36 to 0.88; p=0.01). There were no increased bleeding or wound complications associated with sCP+A (point estimate 1.23, 95% CI 0.68 to 2.2, p=0.50).

Conclusion

In this large trauma cohort, adjunctive aspirin was independently associated with a significant reduction in VTE and may represent a potential strategy to safely mitigate VTE risk in trauma patients. Further prospective studies evaluating the addition of aspirin to heparinoid-based VTE chemoprophylaxis regimens should be sought.

Level of evidence

Level III/therapeutic.

Pediatric Perioperative Clinical Pharmacy Practice: Clinical Considerations and Management: An Opinion of the Pediatrics and Perioperative Care Practice and Research Networks of the American College of Clinical Pharmacy

Pediatric perioperative clinical pharmacists are uniquely positioned to provide therapeutic and medication management expertise at a particularly vulnerable transition of care from the preoperative space, through surgery, and postoperative setting. There are many direct-patient care activities that are included in the role of the pediatric perioperative pharmacist, as well as many opportunities to develop effective, optimized, and safe medication use processes. This article outlines many of the areas in which a pediatric perioperative clinical pharmacist may intervene.

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.

Review of Therapeutic Options for the Prevention of VTE in Total Joint Arthroplasty

Hip and knee arthroplasty patients are at high risk of perioperative venous thromboembolic events (VTE). VTE has been well studied in this population and it is recommended that total joint arthroplasty recipients receive chemoprophylactic anticoagulation due to risk factors inherent to the surgical intervention. There are few concise resources for the orthopedic surgeon that summarize data regarding post-operative anticoagulation in the context of currently available therapeutic options and perioperative standards of practice. The periodic reexamination of literature is essential as conclusions drawn from studies predating perioperative protocols that include early mobilization and sequential compression devices as standards of practice in total joint arthroplasty are no longer generalizable to modern-day practice. We reviewed a large number of recently published research studies related to post-operative anticoagulation in total joint arthroplasty populations that received a high Level of Evidence grade. Current literature supports the use of oral aspirin regimens in place of more aggressive anticoagulants, particularly among low risk patients. Oral aspirin regimens appear to have the additional benefit of lower rates of bleeding and wound complications. Less consensus exists among high risk patients and more potent anticoagulants may be indicated. However, available evidence does not demonstrate clear superiority among current options, all of which may place patients at a higher risk of bleeding and wound complications. In this situation, chemoprophylactic selection should reflect specific patient needs and characteristics.

Thromboprophylaxis an update of current practice: Can we reach a consensus?

Diagnosis, prophylaxis, and management of venous thromboembolism (VTE) in patients with fractures remain a highly controversial topic with little consensus in clinical practice or the literature. The following manuscript represents a summary of evidence presented at the 2017 OTA Annual Meeting Symposium; "Thromboprophylaxis an Update of Current Practice: Can We Reach A Consensus?" The need for prophylaxis in pelvic and acetabular fracture patients; the existing body of evidence related to VTE, pulmonary embolism (PE), and prophylaxis for patients with fractures about the knee; current evidence in Edinburgh Scotland, regarding VTE prophylaxis in patients with isolated ankle fractures and the risk of VTE in patients with a hip fracture are topics that are addressed. The reader will benefit from the wisdom of this compilation of global contributions on thromboprophylaxis.

Aspirin Compared with Anticoagulation to Prevent Venous Thromboembolism After Knee or Hip Arthroplasty: a Large Retrospective Cohort Study

BACKGROUND

Although guidelines now allow the use of aspirin as an alternative to anticoagulants for venous thromboembolism prophylaxis after knee or hip arthroplasty, there is limited data on contemporary use and outcomes with aspirin.

OBJECTIVE

To describe the use of pharmacologic thromboprophylaxis and to assess venous thromboembolic risk with aspirin compared with anticoagulation after knee or hip arthroplasty.

DESIGN

Retrospective cohort study using data from the US MedAssets database.

PATIENTS

Adults with a principal discharge diagnosis of knee or hip arthroplasty between January 1, 2013, and December 31, 2014.

MAIN MEASURES

We identified charges for medications used for thromboprophylaxis within 7 days after the index surgery from billing records. The primary outcome was postoperative venous thromboembolism identified by International Classification of Diseases, 9th edition codes, from the index hospitalization, rehospitalization within 30 days, or during an outpatient visit within 90 days postoperatively. We compared postoperative thromboembolic risk in patients receiving aspirin-only and those receiving anticoagulants using propensity score-adjusted multivariable logistic regression models.

KEY RESULTS

We identified 74,234 patients with knee arthroplasty and 36,192 with hip arthroplasty who received pharmacologic thromboprophylaxis. Aspirin-only was used in 27.9% of all patients, while 24.2% and 24.1% received warfarin or enoxaparin as prophylactic monotherapy, respectively. Postoperative venous thromboembolism occurred in 495 (0.67%) patients undergoing knee arthroplasty and 145 (0.40%) undergoing hip arthroplasty. Aspirin-only was not related to increased odds of postoperative venous thromboembolism compared with anticoagulants in multivariable adjusted analyses (odds ratio [OR] 0.70; 95% confidence interval [CI], 0.56-0.87, and OR 0.93; 95% CI, 0.62-1.38 for knee or hip arthroplasty, respectively).

CONCLUSIONS

More than a fourth of all patients received aspirin as the sole antithrombotic agent after knee or hip arthroplasty. Postoperative thromboprophylaxis with aspirin-only was not associated with a higher risk of postoperative venous thromboembolism compared with anticoagulants after hip or knee arthroplasty.

Aspirin for prevention of venous thromboembolism in recipients of major lower-limb orthopedic surgery: a systematic review of Level I evidence

INTRODUCTION

Major lower-limb orthopedic surgery recipients are at increased risk of venous thromboembolism (VTE). The optimal strategy for preventing VTE is a topic of ongoing debate. The use of aspirin has been implicated in reducing VTE events and is potentially advantageous compared to other agents in respect to cost, access, route of administration and reduced adverse effects such as bleeding.

EVIDENCE ACQUISITION

A systematic search for Level I evidence (systematic reviews and meta-analyses of randomised-controlled trials) was performed in April 2019 to evaluate the use of aspirin for primary and secondary VTE prophylaxis compared to alternative chemical and mechanical strategies. This search encompassed three electronic databases (Pubmed, Embase and the Cochrane Database of Systematic Reviews). All references of included studies were screened for additional studies. Data was compiled and compared to the recommendations and guidelines published by major institutions. Included studies were appraised with the aid of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist.

EVIDENCE SYNTHESIS

In total, 21 studies were included. Interventions and outcomes identified were heterogeneous across studies. Most statistical tests applied found no difference between aspirin and other interventions in regards to deep vein thrombosis, pulmonary embolism, bleeding and mortality outcomes.

CONCLUSIONS

Aspirin may be a viable alternative to established thromboprophylactic regimes for primary prevention of VTE, however in the setting of secondary prevention it is generally less efficacious. Future studies should have clearly identified and comparable outcome measures, with direct comparisons and assessment of intervention combination, dosing and treatment duration.

Is Obesity Associated With Increased Risk of Deep Vein Thrombosis or Pulmonary Embolism After Hip and Knee Arthroplasty? A Large Database Study

BACKGROUND

Deep venous thrombosis (DVT) and pulmonary embolus (PE) remain an important cause of morbidity and mortality after THA and TKA. Prior recommendations have advocated for more aggressive prophylaxis for patients with obesity, whereas the evidence supporting these recommendations is conflicting and often based on underpowered studies.

QUESTIONS/PURPOSES

(1) What is the association between obesity and DVT and PE after primary and revision THA and TKA? (2) Is there a body mass index (BMI) threshold beyond which DVT and PE risk is elevated?

METHODS

We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2008 to 2016 to evaluate the reported 30-day rates of DVT, PE, and combined venous thromboembolism (VTE) after primary THA, primary TKA, revision THA, and revision TKA according to BMI as a continuous variable and a categorical variable as defined by the World Health Organization cutoffs for underweight, normal weight, overweight, and obesity. This database is risk-adjusted and designed to capture complications after surgery, thus making it ideal for this study. The diagnosis of DVT and PE is included in the ACS-NSQIP database for any DVT or PE requiring treatment. Proximal versus distal DVT is not specified within the database. Multivariate logistic regression was performed to determine if obesity was independently associated with DVT and PE risk by controlling for age, sex, race, American Society of Anesthesiologists score, diabetes, hypertension, smoking status, general anesthesia, and hypoalbuminemia.

RESULTS

After controlling for potential confounding variables such as medical comorbidities and procedure type, patients undergoing primary and revision THA and TKA with World Health Organization classification as underweight (BMI < 18.5 kg/m), overweight (BMI 25-29.9 kg/m), Class I obese (BMI 30-34.9 kg/m), Class II obese (BMI 35-39.9 kg/m), or Class III obese (BMI ≥ 40 kg/m) did not demonstrate an association with increased risk of DVT compared with patients classified as normal weight (BMI 18.5-25 kg/m). Compared with patients undergoing primary THA classified as normal weight, the risk of PE was elevated in patients with Class II obesity (odds ratio [OR], 2.36; 95% confidence interval [CI], 1.23-4.50; p = 0.009) and all heavier categories. Compared with patients undergoing TKA classified as normal weight, the risk of PE was elevated in patients classified as overweight (OR, 1.56; 95% CI, 1.03-2.36; p = 0.035) and all heavier categories.

CONCLUSIONS

This large administrative database study suggests that patient classification as overweight or obese is associated with increased risk of development of PE but not DVT after primary THA or TKA. Because aggressive pharmacologic anticoagulation regimens can decrease the DVT rate but have not been shown to affect the rate of PE or death, the data do not currently support increased anticoagulation in patients with obesity without other risk factors for VTE undergoing THA or TKA. Additional studies are required to refine VTE prophylaxis protocols to reduce PE risk while maintaining acceptable postoperative bleeding risk.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Aspirin Alone Is Not Enough to Prevent Deep Venous Thrombosis After Total Joint Arthroplasty

Thromboembolic events after total joint arthroplasty are potentially devastating complications. This study evaluated the efficacy of 4 different anticoagulants in preventing deep venous thrombosis and pulmonary embolism after total joint arthroplasty. The demographics and anticoagulant use (warfarin, enoxaparin, and aspirin with and without outpatient mechanical pumps) for patients who underwent primary unilateral total joint arthroplasties performed by a single surgeon from January 2013 to October 2014 were retrospectively reviewed. All patients underwent lower extremity ultrasound at the 3-week postoperative visit. A total of 613 primary unilateral total joint arthroplasties met the study inclusion criteria. There were 288 primary total knee arthroplasties and 325 primary total hip arthroplasties. The patients were 62.2% female, having a mean age of 67.6±10.6 years and a mean body mass index of 30.2±5.9 kg/m². There were 119 patients in group 1 (aspirin alone), 40 patients in group 2 (aspirin plus pumps), 246 patients in group 3 (warfarin), and 208 patients in group 4 (enoxaparin). The overall 3-week symptomatic and asymptomatic deep venous thrombosis and symptomatic pulmonary embolism rates in the entire cohort were 5.7% and 0.3%, respectively. The venous thromboembolism rate was significantly affected by the anticoagulant of choice (P<.01). Compared with aspirin alone, warfarin decreased the risk of venous thromboembolism (P<.01). Increasing age led to increased risk of venous thromboembolism (P=.05). This study indicated that aspirin chemoprophylaxis alone was not as efficacious as warfarin and enoxaparin in preventing asymptomatic and symptomatic venous thromboembolism found during routine postoperative surveillance with lower extremity ultrasound. Aspirin alone may be inadequate and should be augmented with an outpatient mechanical pump as part of multimodal prophylaxis. [Orthopedics. 2019; 42(1):48-55.].

Evaluation of a Simplified Risk Stratification Twice-Daily Aspirin Protocol for Venous Thromboembolism Prophylaxis After Total Joint Replacement

OBJECTIVE

To determine using a simplified risk-stratified protocol to select candidates for aspirin therapy have similar death and postoperative complications as universal warfarin therapy in patients undergoing total joint replacement (TJR).

METHODS

Retrospective cohort study comparing 30-day postoperative outcomes 6 months before and after the implementation of the aspirin protocol (January 1, 2015) in patients undergoing TJR. The control group was comprised of patients using warfarin for VTE prophylaxis. The protocol group included patients who used aspirin 325 mg twice-daily or warfarin if deemed high thrombotic risk or aspirin intolerant by the criteria set forth by the aspirin protocol.

RESULTS

This study included 449 patients. No difference was found in the rates of 30-day postoperative bleeding, VTE, death, composite end point of VTE and death, and length of stay between the control and the protocol groups (all P > .05). Thirty-day postoperative surgical site infections (SSIs; 5.8% vs 1.2%; P = .02) and return to operative room (OR; 3.9% vs 0.4%; P = .03) were less frequent in the protocol group.

CONCLUSION

A simplified risk-stratified protocol used to choose patients for aspirin 325 mg twice-daily therapy is safe and effective in patients undergoing TJR, and SSI and return to OR rates may be lower when compared to universal warfarin therapy.

Comparison of Postoperative Bleeding in Total Hip and Knee Arthroplasty Patients Receiving Rivaroxaban, Enoxaparin, or Aspirin for Thromboprophylaxis

BACKGROUND

Guidelines recommend the use of multiple pharmacologic agents and/or mechanical compressive devices for prevention of venous thromboembolism, but preference for any specific agent is no longer given in regard to safety or efficacy.

OBJECTIVE

To compare postoperative bleeding rates in patients receiving enoxaparin, rivaroxaban, or aspirin for thromboprophylaxis after undergoing elective total hip arthroplasty or total knee arthroplasty.

METHODS

This retrospective cohort analysis evaluated patients who received thromboprophylaxis with either enoxaparin, rivaroxaban, or aspirin. All data were collected from the electronic medical record. The primary outcome was any postoperative bleeding.

RESULTS

A total of 1244 patients were included with 366 in the aspirin, 438 in the enoxaparin, and 440 in the rivaroxaban arms. Those who received aspirin or enoxaparin were less likely to experience any bleeding compared to those patients who received rivaroxaban ( P < .05). There was also a lower rate of major bleeding in these groups, but the differences were not significant.

CONCLUSIONS

Aspirin and enoxaparin conferred similar bleeding risks, and both exhibited less bleeding than patients who received rivaroxaban.

Trends in Deep Vein Thrombosis Prophylaxis and Deep Vein Thrombosis Rates After Total Hip and Knee Arthroplasty

INTRODUCTION

Patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) are at high risk of deep vein thrombosis (DVT) postoperatively, necessitating the use of prophylaxis medications. This investigation used a large claims database to evaluate trends in postoperative DVT prophylaxis and rates of DVT within 6 months after THA or TKA.

METHODS

Truven Health MarketScan Commercial Claims and Encounters and Medicare Supplemental and Coordination of Benefits databases were reviewed from 2004 to 2013 for patients who underwent THA or TKA. Data were collected on patient age, sex, Charlson Comorbidity Index, and hypercoagulability diagnoses. Postoperative medication claims were reviewed for prescribed aspirin, warfarin, enoxaparin, fondaparinux, rivaroxaban, and dabigatran.

RESULTS

A total of 369,483 patients were included in the analysis, of which 239,949 patients had prescription medication claims. Warfarin was the most commonly prescribed anticoagulant. Patients with a hypercoagulable diagnosis had markedly more DVTs within 6 months after THA or TKA. More patients with a hypercoagulable diagnosis were treated with warfarin or lovenox than other types of anticoagulants. A multivariate regression analysis was performed, showing that patients prescribed aspirin, fondaparinux, and rivaroxaban were markedly less likely than those prescribed warfarin or enoxaparin to have a DVT within 6 months after THA or TKA.

CONCLUSION

After THA and TKA, warfarin is the most commonly prescribed prophylaxis. Patients with hypercoagulability diagnoses are at a higher risk of postoperative DVT. The likelihood of DVT within 6 months of THA and TKA was markedly higher in patients treated with warfarin and lovenox and markedly lower in those treated with aspirin, fondaparinux, and rivaroxaban.

LEVEL OF EVIDENCE

Level III.

Otogenic lateral sinus thrombosis in children: proposal of an experience-based treatment flowchart

PURPOSE

To describe the prevalent clinical, laboratory, and radiological features of otogenic lateral sinus thrombosis (OLST) in children; to identify clinical predictors of outcome; to propose a management algorithm derived from experience.

METHODS

A retrospective review was conducted of the clinical records of patients with OLST, treated in a single tertiary care referral center for pediatric disease from 2006 to 2017. The inclusion criteria were pediatric age (0-16 years) and OLST diagnosis confirmed by a pre- and post-contrast CT or venography-MRI scan. Primary outcome measures were early (1-2 months) and late (6 months) sinus recanalization assessed by means of neuroimaging.

RESULTS

Twenty-five patients (8 females and 17 males; mean age = 6 ± 3 years) were included. A genetic abnormality associated with thrombophilia was found in 24 (96%) patients. At diagnosis, anticoagulant treatment with low-molecular-weight heparin (LMWH) was started in all subjects, while surgical treatment (mastoidectomy and tympanostomy tube insertion) was performed in 16/25 (64%) patients. Follow-up neuroimaging showed lateral sinus recanalization in 12/25 (48%) patients after 1-2 months and in 17/25 (68%) after 6 months. At multivariate logistic regression analysis, no significant predictors of the early and late neuroradiological outcome were found.

CONCLUSIONS

All children with OLST should be screened for thrombophilia to decide on treatment duration and to assess the need for future antithrombotic prophylaxis. Immediately after diagnosis, anticoagulant treatment with LMWH should be started according to the international guidelines. Instead, our experience suggests that surgical treatment should not be indicated in all patients, but decided on a case-to-case basis.

PROSPECTIVE STUDY OF ASPIRIN FOR THROMBOEMBOLISM PROPHYLAXIS IN TOTAL HIP ARTHROPLASTY

Objectives:

To evaluate the effectiveness of aspirin as prophylaxis for deep venous thrombosis (DVT) in patients undergoing total hip arthroplasty (THA), and to analyze the incidence of bleeding during the post-operative period.

Methods:

This prospective study carried out in 2017 consisted of 37 patients indicated for THA with high risk for DVT. Immediately after the procedure, aspirin, elastic compression socks and early deambulation were initiated. Doppler ultrasound was performed in the legs 6 days and 6 weeks post-procedure to rule out venous thromboembolism. Hematometric variables and clinical criteria were used to detect bleeding.

Results:

The incidence of VTE (venous thromboembolism) 6 days post-procedure was 21.6%. By 6 weeks post-procedure, it dropped to 8.1%, (p = 0.102). Only 2.7% were diagnosed with VTE, 6 days and also 6 weeks post-procedure. Within the immediate postoperative period, hemoglobin was lower (p < 0.001), in contrast to 6 weeks after surgery, when it returned to baseline levels.

Conclusion:

Aspirin was an effective chemical prophylaxis for venous thromboembolism in high-risk patients who underwent THA. There was no clinical record of postoperative bleeding and hematometric levels suggested that there was no chronic bleeding. Level of Evidence II; Prospective study.

Upper Extremity Deep Venous Thrombosis Prophylaxis After Elective Upper Extremity Surgery

Historically, upper extremity deep venous thromboses (DVTs) have been rare; however, their incidence has increased as awareness has increased. Patients who develop upper extremity DVTs often have multiple comorbidities. However, in the past decade, studies have found a small risk of upper extremity DVTs associated with orthopedic procedures involving the upper extremity. The risk of complications following a DVT, including postthrombotic syndrome and pulmonary embolism, is substantially higher with a DVT of the upper extremity compared with a DVT of the lower extremity. Furthermore, there is no consensus regarding the role and efficacy of prophylactic measures in preventing upper extremity DVT after upper extremity surgery. This article discusses the use of prophylactic agents after elective upper extremity surgery, with an emphasis on the efficacy of commonly used interventions. [Orthopedics. 2018; 41(1):21-27.].

Aspirin for Prophylaxis Against Venous Thromboembolism After Orthopaedic Oncologic Surgery

BACKGROUND

Patients who undergo orthopaedic oncologic surgical procedures are at increased risk of developing a venous thromboembolism (VTE). Guidelines from surgical societies are shifting to include aspirin as a postoperative VTE prophylactic agent. The purpose of this study was to review our experience using aspirin as postoperative VTE prophylaxis for orthopaedic oncologic surgical procedures.

METHODS

This study was a retrospective review of patients diagnosed with a primary malignant soft-tissue or bone tumor or metastatic carcinoma. Demographic information, histopathologic diagnosis, VTE history, surgical procedure, and VTE prophylaxis were analyzed. VTE rates in the overall and prophylactic-specific cohorts were recorded and compared.

RESULTS

A total of 142 distinct surgical procedures in 130 patients were included. VTE prophylaxis with aspirin was used after 103 procedures, and non-aspirin prophylaxis was used after 39. In 33 cases, imaging was used to investigate for VTE because of clinical signs and symptoms. VTE developed after 7 (4.9%) of the 142 procedures. There were 6 deep venous thromboses (DVTs) and 1 pulmonary embolism, and 2 of the VTEs presented in patients with a VTE history. VTE developed in 2.9% (3) of the 103 aspirin cases and 10.3% (4) of the 39 non-aspirin cases. No patient in the aspirin group who had been diagnosed with metastatic carcinoma, malignant soft-tissue sarcoma, lymphoma, or multiple myeloma developed a VTE. Risk factors for VTE development included diabetes mellitus (odds ratio [OR] = 10.40, 95% confidence interval [CI] = 1.61 to 67.30), a history of VTE (OR = 7.26, 95% CI = 1.19 to 44.25), postoperative transfusion (OR = 34.50, 95% CI = 3.94 to 302.01), and estimated blood losses of 250 mL (OR = 1.50, 95% CI = 1.11 to 2.03), 500 mL (OR = 2.26, 95% CI = 1.23 to 4.13), and 1,000 mL (OR = 5.10, 95% CI = 1.52 to 17.04).

CONCLUSIONS

Aspirin may be a suitable and effective option for VTE chemoprophylaxis in patients treated with orthopaedic oncologic surgery, especially those diagnosed with a soft-tissue sarcoma. Research with a more advanced study design is required.

LEVEL OF EVIDENCE

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

Venous Thromboembolism Prophylaxis After TKA: Aspirin, Warfarin, Enoxaparin, or Factor Xa Inhibitors?

BACKGROUND

There is considerable debate regarding the ideal agent for venous thromboembolism (VTE) prophylaxis after TKA. Numerous studies and meta-analyses have yet to provide a clear answer and often omit one or more of the commonly used agents such as aspirin, warfarin, enoxaparin, and factor Xa inhibitors.

QUESTIONS/PURPOSES

Using a large database analysis, we asked: (1) What are the differences in VTE incidence in primary TKA after administration of aspirin, warfarin, enoxaparin, or factor Xa inhibitors? (2) What are the differences in bleeding risk among these four agents? (3) How has use of these agents changed with time?

METHODS

We queried a combined Humana and Medicare database between 2007 and Quarter 1 of 2016, and identified all primary TKAs performed using ICD-9 and Current Procedural Terminology codes. All patients who had any form of antiplatelet or anticoagulation prescribed within 1 year before TKA were excluded from our study cohort. We then identified patients who had either aspirin, warfarin, enoxaparin, or factor Xa inhibitors prescribed within 2 weeks of primary TKA. Each cohort was matched by age and sex. Elixhauser comorbidities and Charlson Comorbidity Index for each group were calculated. We identified 1016 patients with aspirin, and age- and sex-matched 6096 patients with enoxaparin, 6096 patients with warfarin, and 5080 patients with factor Xa inhibitors. Using ICD-9 codes, with the understanding that patients at greater risk may have had more-attentive surveillance, the incidence of postoperative deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding-related complications (bleeding requiring surgical intervention, hemorrhage, hematoma, hemarthrosis), postoperative anemia, and transfusion were identified at 2 weeks, 30 days, 6 weeks, and 90 days postoperatively. A four-way chi-squared test was used to determine statistical significance. Utilization was calculated using compound annual growth rate.

RESULTS

There was a difference in the incidence of DVT at 90 days (p < 0.01). Factor Xa inhibitors (2.9%) had the lowest incidence of DVT followed by aspirin (3.0%) and enoxaparin (3.5%), and warfarin (4.8%). There was a difference in the incidence of PE at 90 days (p < 0.01). Factor Xa inhibitors (0.9%) had the lowest incidence of PE followed by enoxaparin (1.1%), aspirin (1.2%), and warfarin (1.6%). There was a difference in the incidence of postoperative anemia at 90 days (p < 0.01). Aspirin (19%) had the lowest incidence of postoperative anemia followed by warfarin (22%), enoxaparin (23%), and factor Xa inhibitors (23%). There was a difference in the incidence of a blood transfusion at 90 days (p < 0.01). Aspirin (7%) had the lowest incidence of a blood transfusion followed by factor Xa inhibitors (9%), warfarin (12%), and enoxaparin (13%). There were no differences in bleeding-related complications (p = 0.81) between the groups. Aspirin use increased at a compound annual growth rate of 30%, enoxaparin at 3%, and factor Xa inhibitors at 43%, while warfarin use decreased at a compound annual growth rate of -3%.

CONCLUSIONS

Factor Xa inhibitors had the highest growth in utilization during our study period, followed by aspirin, when compared with enoxaparin and warfarin. When selected for the right patient, factor Xa inhibitors provided improved VTE prophylaxis compared with enoxaparin and warfarin, with a lower rate of blood transfusion. Aspirin provided comparable VTE prophylaxis compared with factor Xa inhibitors with improved VTE prophylaxis compared with enoxaparin and warfarin with the lowest risk of bleeding.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The risk of venous thromboembolism with aspirin compared to anticoagulants after hip and knee arthroplasty

BACKGROUND

Recent guidelines include aspirin as an option to prevent venous thromboembolism (VTE) in selected patients undergoing hip or knee replacement surgery. However, the efficacy of aspirin after arthroplasty has not been well-defined, particularly in more contemporary patient populations. We compared rates of post-operative VTE between patients who received aspirin-only versus anticoagulants after hip or knee arthroplasty, using data from a large US-based administrative database.

MATERIALS AND METHODS

We conducted a retrospective cohort study of 231,780 adults who underwent total knee arthroplasty and 110,621 who underwent total hip arthroplasty in 2009-2012 and who received pharmacologic VTE prophylaxis (aspirin or anticoagulant) within the first 7days after surgery. We compared the risk of post-operative VTE between patients receiving aspirin-only vs. anticoagulants, controlling for clinical and hospital characteristics using multivariable logistic regression with propensity score adjustment.

RESULTS

Aspirin-only prophylaxis was administered to 7.5% of patients after knee arthroplasty and 8.0% after hip arthroplasty. Post-operative VTE was diagnosed in 2217 (0.96%) patients after knee arthroplasty and 454 (0.41%) after hip arthroplasty. Compared to anticoagulants, aspirin was not associated with a higher risk for post-operative VTE either after knee arthroplasty (adjusted odds ratio and 95% confidence interval [OR] 0.34 [0.24-0.48]) or hip arthroplasty (OR 0.82 [0.45-1.51]).

CONCLUSIONS

Aspirin was uncommonly administered as the sole prophylactic agent after hip or knee arthroplasty in this study. However, patients who received aspirin-only had similar rates of post-operative VTE compared to patients who received anticoagulants. Further research should focus on distinguishing which patients benefit more from anticoagulants versus aspirin after arthroplasty.

[Posttraumatic thromboembolic complications: Incidence, risk factors, pathophysiology and prevention]

Venous thromboembolism (VTE) remains a major challenge in critically ill patients. Subjects admitted in intensive care unit (ICU), in particular trauma patients, are at high-risk for both deep vein thrombosis (DVT) and pulmonary embolism (PE). The rate of symptomatic PE in injured patients has been reported previously ranging from 1 to 6%. The high incidence of posttraumatic venous thromboembolic events is well known. In fact, major trauma is a hypercoagulable state. Several factors placing the individual patient at a higher risk for the development of DVT and PE have been suggested: high ISS score, meningeal hemorrhage and spinal cord injuries have frequently been reported as a significant risk factor for VTEs after trauma. Posttraumatic pulmonary embolism traditionally occurs after a period of at least 5 days from trauma. The prevention can reduce the incidence and mortality associated with the pulmonary embolism if it is effective. There is no consensus is now available about the prevention of venous thromboembolism in trauma patients.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Worldwide adherence to ACCP guidelines for thromboprophylaxis after major orthopedic surgery: A systematic review of the literature and meta-analysis

INTRODUCTION

Increased risk of venous thromboembolism following major orthopedic surgery (MOS) is well described. The American Academy of Chest Physician (ACCP) has generated evidence-based recommendations for thromboprophylaxis; however, there is a gap between guidelines recommendations and clinical practice. The aim of this study is to compare worldwide adherence rates to the last 4 editions of ACCP guidelines for thromboprophylaxis after MOS.

MATERIALS AND METHODS

A systematic review of literature and meta-analysis was performed. Studies reporting adherence to ACCP guidelines between January 2004 and October 2014 were included. Adherence rates after MOS for in-hospital (IH), extended (EXT), and global thromboprophylaxis (in-hospital plus extended) were assessed.

RESULTS

Of 3993 titles, 13 studies reporting data of 35,303 patients were selected. Studies assessing the 6th, 7th or 8th editions of ACCP guidelines were found. No studies evaluating the 9th edition were available. For MOS, global adherence rates for the 6th, 7th and 8th editions were 62% (95% CI: 61%-63%), 70% (95% CI: 69%-71%), and 42% (95% CI: 41%-43%), respectively. Likewise, in-hospital adherence was 52% (95% CI: 50%-54%), 51% (95% CI: 50%-52%) and 85% (95% CI: 84%-86%). For extended prophylaxis, adherence rates were reported only for the 8th edition (59%; 95% CI: 58%-60%).

CONCLUSIONS

Adherence to ACCP recommendations for thromboprophylaxis during hospitalization has increased over time. Nevertheless, adherence rates to global thromboprophylaxis decrease due to an insufficient implementation of recommendations after discharge.

Comparison of Postoperative Bleeding in Total Hip and Knee Arthroplasty Patients Receiving Rivaroxaban or Enoxaparin

Background: The Regulation of Coagulation in Orthopedic Surgery to Prevent Deep Venous Thrombosis and Pulmonary Embolism (RECORD) 1 to 4 trials compared rivaroxaban 10 mg daily with commonly used doses of enoxaparin and demonstrated similar rates of VTE and bleeding. Objective: To evaluate bleeding events between patients who received enoxaparin or rivaroxaban for prevention of venous thromboembolism (VTE) following total hip arthroplasty (THA) or total knee arthroplasty (TKA). Methods: Retrospective cohort that compared patients undergoing THA and TKA who received enoxaparin (enoxaparin) with those who received rivaroxaban (rivaroxaban) and also with those who received enoxaparin in the RECORD 1 to 4 trials (enoxaparin RECORD). The primary outcome was any postoperative bleeding, defined as a composite of major and clinically relevant nonmajor bleeding based on the definitions in the RECORD 1 to 4 trials. Results: There was a lower rate of any postoperative bleeding (2.2% vs 6.8%, P = 0.004) in patients who received enoxaparin compared with rivaroxaban, and bleeding rates between the enoxaparin group and the enoxaparin RECORD groups were similar (2.2% vs 2.5%, P = 0.085). Major bleeding in the enoxaparin group (0.2%) was not significantly different from that in the rivaroxaban group (1.4%, P = 0.12) or the RECORD group (0.2%, P = 0.93). Clinically relevant nonmajor bleeding was also lower in the enoxaparin group compared with the rivaroxaban group (2.0% vs 5.5%, P = 0.012). Conclusions: The use of enoxaparin for VTE prophylaxis following THA and TKA was associated with a lower rate of the primary outcome (any postoperative bleeding) compared with the use of rivaroxaban in a similar cohort of patients.

Transitions in the Prophylaxis, Treatment and Care of Patients with Venous Thromboembolism

INTRODUCTION

Patients experience numerous transitions, including changes in clinical status, pharmacologic treatment and prophylaxis, and progression through the physical locations of their healthcare setting as they advance through a venous thromboembolism (VTE) clinical experience. This review provides an overview of these transitions and highlights how they can impact clinical care.

METHODS

Major public resources (PubMed, MEDLINE, and Google Scholar) were searched using various combinations of the terms: "venous thromboembolism", "deep vein thromboses", "pulmonary embolism", "transitions in care", and "hospital protocols" to identify narrative reviews, professional guidelines, or primary manuscripts reporting protocol development strategies and/or clinical data, published in English from 2010 through January 2015. The studies included in this review were selected on the basis of extensive reading of the literature and the author's clinical expertise.

RESULTS

VTE treatment and prophylaxis is a dynamic process requiring ongoing patient assessments and adjustments to therapeutic strategies as the patient progresses through various hospital and outpatient settings. Throughout these transitions in care, physicians need to be vigilant of any changes in the patient's clinical condition which may impact the patient's risk of VTE, and re-evaluate the intervention(s) employed when such changes occur. A standardized, interdisciplinary VTE clinical pathway developed for medical patients with acute VTE resulted in decreased utilization of hospital resources and healthcare costs, suggesting that further research is warranted in this area.

CONCLUSION

The prevention and management of VTE can be optimized by the development and local implementation of standardized evidence-based clinical pathways.

Effects of anticoagulation on markers of activation of clotting following major orthopedic surgery

INTRODUCTION

This study examines makers of activation of clotting following three chemoprophylactic regimens used for prevention of postoperative venous thromboembolic disease (TED) following high-risk surgery for TED.

METHODS

Patients having elective primary knee or hip replacement surgery received variable dose warfarin (target international normalized ratios 2.0-2.5), 1 mg warfarin daily starting 7 days preoperatively or aspirin 325 mg daily starting on the day of surgery. Twelve patients in each group were treated for 28 ± 2 days. Thrombin-antithrombin (T-AT) and prothrombin fragment F1 + 2 were measured at baseline and postoperative days 3 and 28 ± 2.

RESULTS

Thrombin-antithrombin and F1 + 2 on postoperative day 3 were equal for the study groups. By days 28 ± 2, variable dose warfarin therapy group suppressed production of F1 + 2 (P = 0.002) with no difference in the T-AT accumulation. F1 + 2 for other patients overlapped the normal range.

CONCLUSION

The signals of activated clotting following surgery did not differentiate the three regimens on postoperative day 3. Variable dose warfarin was associated with suppression of F1 + 2 after 1 month of therapy, with no effect on accumulation of T-AT. Fixed low-dose warfarin started 7 days prior to surgery and aspirin are not inferior on postoperative day 3, but appear to be inferior over a longer treatment.

New insights into the mechanisms of action of aspirin and its use in the prevention and treatment of arterial and venous thromboembolism

The antithrombotic action of aspirin has long been recognized. Aspirin inhibits platelet function through irreversible inhibition of cyclooxygenase (COX) activity. Until recently, aspirin has been mainly used for primary and secondary prevention of arterial antithrombotic events. The aim of this study was to review the literature with regard to the various mechanisms of the newly discovered effects of aspirin in the prevention of the initiation and development of venous thrombosis. For this purpose, we used relevant data from the latest numerous scientific studies, including review articles, original research articles, double-blinded randomized controlled trials, a prospective combined analysis, a meta-analysis of randomized trials, evidence-based clinical practice guidelines, and multicenter studies. Aspirin is used in the prevention of venous thromboembolism (VTE), especially the prevention of recurrent VTE in patients with unprovoked VTE who were treated with vitamin K antagonists (VKAs) or with non-vitamin K antagonist oral anticoagulants (NOACs). Numerous studies have shown that aspirin reduces the rate of recurrent VTE in patients, following cessation of VKAs or NOACs. Furthermore, low doses of aspirin are suitable for long-term therapy in patients recovering from orthopedic or other surgeries. Aspirin is indicated for the primary and secondary prevention as well as the treatment of cardiovascular diseases, including acute coronary syndrome, myocardial infarction, peripheral artery disease, acute ischemic stroke, and transient ischemic attack (especially in atrial fibrillation or mechanical heart valves). Aspirin can prevent or treat recurrent unprovoked VTEs as well as VTEs occurring after various surgeries or in patients with malignant disease. Recent trials have suggested that the long-term use of low-dose aspirin is effective not only in the prevention and treatment of arterial thrombosis but also in the prevention and treatment of VTE. Compared with VKAs and NOACs, aspirin has a reduced risk of bleeding.

A Guide to Improving the Care of Patients with Fragility Fractures, Edition 2

Over the past 4 decades, much has been learned about the pathophysiology and treatment of osteoporosis, the prevention of fragility fractures, and the perioperative management of patients who have these debilitating injuries. However, the volume of published literature on this topic is staggering and far too voluminous for any clinician to review and synthesize by him or herself. This manuscript thoroughly summarizes the latest research on fragility fractures and provides the reader with valuable strategies to optimize the prevention and management of these devastating injuries. The information contained in this article will prove invaluable to any health care provider or health system administrator who is involved in the prevention and management of fragility hip fractures. As providers begin to gain a better understanding of the principles espoused in this article, it is our hope that they will be able to use this information to optimize the care they provide for elderly patients who are at risk of or who have osteoporotic fractures.

Aspirin and multiple sclerosis

Aspirin is widely used to lessen the risks of cardiovascular events. Some studies suggest that patients with multiple sclerosis have an increased risk for some cardiovascular events, for example, venous thromboembolism and perhaps ischemic strokes, raising the possibility that aspirin could lessen these increased risks in this population or subgroups (patients with limited mobility and/or antiphospholipid antibodies). However, aspirin causes a small increased risk of hemorrhagic stroke, which is a concern as it could potentially worsen a compromised blood-brain barrier. Aspirin has the potential to ameliorate the disease process in multiple sclerosis (for example, by limiting some components of inflammation), but aspirin also has the potential to inhibit mitochondrial complex I activity, which is already reduced in multiple sclerosis. In an experimental setting of a cerebral ischemic lesion, aspirin promoted the proliferation and/or differentiation of oligodendrocyte precursors, raising the possibility that aspirin could facilitate remyelination efforts in multiple sclerosis. Other actions by aspirin may lead to small improvements of some symptoms (for example, lessening fatigue). Here we consider potential benefits and risks of aspirin usage by patients with multiple sclerosis.

Unmet Needs in Anticoagulant Therapy: Potential Role of Rivaroxaban

The new generation of non-vitamin K antagonist oral anticoagulants (NOACs) have been welcomed as a convenient alternative to warfarin. Three new oral anticoagulants, dabigatran etexilate, rivaroxaban and apixaban have been approved for the prevention of stroke and systemic embolism (SSE) in patients with atrial fibrillation (AF) and the prevention of venous thromboembolic events (VTEs) in patients who have undergone elective hip or knee replacement surgery. Dabigatran etexilate and rivaroxaban are also indicated for the treatment of VTE and the long-term prevention of recurrent deep vein thrombosis (DVT) and pulmonary embolism (PE). A fourth agent, edoxaban, has been successfully tested for several indications but is not yet approved for use in North America or Europe. Building on these successes, new trials are planned to address remaining unmet needs and knowledge gaps. This paper examines the unresolved issues in anticoagulant therapy with a focus on planned and ongoing trials.

Deep-vein thrombosis prophylaxis in foot and ankle surgery: what is the current state of practice?

BACKGROUND

When contemplating thromboprophylaxis for patients undergoing elective foot and ankle surgery the potential for complications secondary to venous thromboembolism (VTE) must be balanced against the cost, risk, and effectiveness of prophylactic treatment. The incidence of pulmonary embolism (PE) following foot and ankle surgery is considerably lower than after hip or knee surgery. The purpose of this study was to assess current trends in practice regarding VTE prophylaxis among expert orthopaedic foot and ankle surgeons.

METHODS

An e-mail-based survey of active AOFAS (American Orthopaedic Foot and Ankle Society) committee members was conducted (n = 100). Surgeons were questioned as to their use, type, and duration of thromboprophylaxis following elective ankle fusion surgery. Scenarios included the following: (1) A 50-year-old woman with no risk factors; (2) a 50-year-old woman with a history of PE; and (3) a 35-year-old woman actively using birth control pills (BCPs).

RESULTS

The response rate for the survey was 80% (80/100). Replies regarding the use of thromboprophylaxis were as follows: (1) in the absence of risk factors, 57% of respondents (45/80) answered, "No prophylaxis required"; (2) for the scenario in which the patient had experienced a previous PE, 97.5% of respondents (78/80) answered, "Yes" to prophylaxis use; (3) for the scenario in which the patient was on BCP, 61.3% of respondents (49/80) stated that they would give some type of thromboprophylaxis. The most commonly recommended methods of prophylaxis were aspirin, 49% (24/49), and low-molecular-weight heparin, 47% (23/49). The recommended length of time for thromboprophylaxis varied widely, from 1 day to more than 6 weeks.

CONCLUSION

. There remains wide variation in the practice of deep-vein thrombosis thromboprophylaxis within the foot and ankle community. Because risks for foot and ankle patients differ from those in the well-studied areas of hip and knee, specific guidelines are needed for foot and ankle surgery.

LEVELS OF EVIDENCE

Level V: Expert Opinion.

Cost-effective prophylaxis against venous thromboembolism after total joint arthroplasty: warfarin versus aspirin

Although recent guidelines suggest aspirin for venous thromboembolism (VTE) prophylaxis in low risk patients following total hip arthroplasty (THA) and total knee arthroplasty (TKA), there are no cost-effectiveness studies comparing aspirin and warfarin. In a Markov cohort cost-effectiveness analysis, we found that aspirin cost less and saved more quality-adjusted life-years (QALYs) than warfarin in all age groups. Cost per QALY gained by aspirin was $24,506.20 at age of 55 and $47,148.10 at the age of 85 following THA and $15,117.20 and $24,458.10 after TKA, which were greater than warfarin. In patients undergoing THA/TKA without prior VTE, aspirin is more cost-effective prophylactic agent than warfarin. Warfarin might be a better prophylaxis in TKA patients with high probability of VTE and very low probability of bleeding.

Prevention of venous thromboembolic events following femoroacetabular osteoplasty: aspirin is enough for most

BACKGROUND

As hip-preservation surgery is performed in a particularly young and active group of patients, the knowledge accrued in the fields of hip arthroplasty and hip fracture care regarding postoperative thromboprophylaxis cannot be extrapolated to this patient population. Recommendations based on the evidence for each particular surgical procedure and population is desirable. For these reasons, the purpose of our study is to describe the rate of clinically relevant venous thromboembolism (VTE) and anticoagulation-related complications observed in patients undergoing hip-preservation surgery through mini-open femoracetabular osteoplasty (FAO) with a formal postoperative thromboprophylaxis protocol of aspirin dosing.

METHODS

A prospective case series of 407 consecutive FAO procedures in 375 patients of mean age 34.5 ± 11.1 years (range 15-62 years) were followed six weeks post operatively to document the presence of clinically relevant VTE as well as major bleeding events, as defined by the most recent American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. All patients were given aspirin 325 mg by mouth daily for two to four weeks.

RESULTS

There was one case of distal DVT in a 31-year-old male with no specific risk factors. No cases of pulmonary embolism were observed. There were no major bleeding events or reoperations due to postsurgical haematoma. There were no deaths. The crude incidence of clinically relevant VTE was 1 per 407 procedures (0.25%).

CONCLUSION

Aspirin is a safe and effective modality to provide thromboprophylaxis in patients undergoing hip-preservation surgery. The rate of VTE that we observed is, thus far, the lowest in comparison to other published series of hip preservation surgery that specifically focused on this complication.

Postoperative venous thrombotic events in Asian elderly patients with surgically treated hip fractures with and without chemoprophylaxis

BACKGROUND AND PURPOSE

Chemothromboprophylaxis for hip fracture surgery has been under-practiced in Asia. We investigate the postoperative incidence of venous thrombotic events (VTE) in elderly Asian patients with hip fractures.

PATIENTS AND METHODS

Patients over 60 years old with surgically treated hip fractures were reviewed. All patients followed a hip fracture protocol, which included a post-operative ultrasound Doppler venous scan of both lower limbs five days after injury to detect any deep vein thrombosis (DVT). All patients were given mechanical prophylaxis. Patients who had additional chemoprophylaxis were included.

RESULTS

From 2010 to 2012, 454 patients were reviewed. The overall incidence of DVT was 6.4% (29 patients). The incidence of PE was 1.3% (six patients). There was no significant correlation between DVT and age, gender, race, hypertension, diabetes mellitus, end stage renal failure, type of fracture and operation, preoperative haemoglobin, platelet count or urea and creatinine levels. Sixteen DVTs (55.2%) were on the ipsilateral side as the fracture, eight (27.6%) were on the contralateral side and five (17.2%) were bilateral. Chemoprophylaxis was not given to 399 patients, of which 27 (6.8%) developed DVT. Ten (2.5%) were proximal DVTs in which four (1%) developed PE. One (0.25%) patient developed PE without DVT. Fifty-five patients were on chemoprophylaxis, of which two (3.6%) developed DVT. Both were proximal DVTs with one subsequently developing PE.

CONCLUSIONS

The incidence of VTE in Asian patients may be lower compared to Western populations when mechanical prophylaxis is used. Chemoprophylaxis may assist in reducing the rates of DVT but not PE. The low incidence may not justify the use of routine chemoprophylaxis.

Review article: Perioperative care in enhanced recovery for total hip and knee arthroplasty

Enhanced recovery pathways for total hip and knee arthroplasty can reduce length of hospital stay and perioperative morbidity. 22 studies were reviewed for identification of perioperative care interventions, including preoperative (n=4), intra-operative (n=8), and postoperative (n=4) care interventions. Factors that improve outcomes included use of pre-emptive and multimodal analgesia regimens to reduce opioid consumption, identification of patients with poor nutritional status and provision of supplements preoperatively to improve wound healing and reduce length of hospital stay, use of warming systems and tranexamic acid, avoidance of drains to reduce operative blood loss and subsequent transfusion, and early ambulation with pharmacological and mechanical prophylaxis to reduce venous thromboembolism and to speed recovery.

Aspirin Increases the Risk of Venous Thromboembolism in Surgical Patients

The risk of venous thromboembolism (VTE) for patients taking an antiplatelet agent is largely unknown. This study aimed to investigate the association between antiplatelet agent use before admission with the risk of in-hospital VTE in surgical intensive care unit (ICU) patients. A retrospective review of all patients admitted to the surgical ICU at a Level I trauma center over 30 months was performed. Patients who underwent diagnostic imaging for VTE were selected. Patients were divided based on whether or not antiplatelet agents were used before admission (APTA vs NAPTA). The primary outcome was VTE occurrence. A forward logistic regression model was used to identify factors independently associated with the primary outcome. During the study period, 461 (24%) patients met inclusion criteria: 70 (15%) APTA and 391 (85%) NAPTA. After adjusting for confounding factors, APTA patients were at a significantly higher risk for developing VTE (59 vs 40%; adjusted odds ratio, 1.8; 95% confidence interval, 1.0 to 3.0; adjusted P = 0.04). Whether or not antiplatelet agents were resumed during the hospital stay and the day on which they were resumed did not affect VTE risk. In conclusion, surgical ICU patients receiving antiplatelet agents before admission are at a significantly higher risk for development of VTE.

Aspirin versus anticoagulation for prevention of venous thromboembolism major lower extremity orthopedic surgery: a systematic review and meta-analysis

BACKGROUND

Hip fracture surgery and lower extremity arthroplasty are associated with increased risk of both venous thromboembolism and bleeding. The best pharmacologic strategy for reducing these opposing risks is uncertain.

PURPOSE

To compare venous thromboembolism (VTE) and bleeding rates in adult patients receiving aspirin versus anticoagulants after major lower extremity orthopedic surgery.

DATA SOURCES

Medline, Cumulative Index to Nursing and Allied Health Literature, and the Cochrane Library through June 2013; reference lists, ClinicalTrials.gov, and scientific meeting abstracts.

STUDY SELECTION

Randomized trials comparing aspirin to anticoagulants for prevention of VTE following major lower extremity orthopedic surgery.

DATA EXTRACTION

Two reviewers independently extracted data on rates of VTE, bleeding, and mortality.

DATA SYNTHESIS

Of 298 studies screened, 8 trials including 1408 participants met inclusion criteria; all trials screened participants for deep venous thrombosis (DVT). Overall rates of DVT did not differ statistically between aspirin and anticoagulants (relative risk [RR]: 1.15 [95% confidence interval {CI}: 0.68-1.96]). Subgrouped by type of surgery, there was a nonsignificant trend favoring anticoagulation following hip fracture repair but not knee or hip arthroplasty (hip fracture RR: 1.60 [95% CI: 0.80-3.20], 2 trials; arthroplasty RR: 1.00 [95% CI: 0.49-2.05], 5 trials). The risk of bleeding was lower with aspirin than anticoagulants following hip fracture repair (RR: 0.32 [95% CI: 0.13-0.77], 2 trials), with a nonsignificant trend favoring aspirin after arthroplasty (RR: 0.63 [95% CI: 0.33-1.21], 5 trials). Rates of pulmonary embolism were too low to provide reliable estimates.

CONCLUSION

Compared with anticoagulation, aspirin may be associated with higher risk of DVT following hip fracture repair, although bleeding rates were substantially lower. Aspirin was similarly effective after lower extremity arthroplasty and may be associated with lower bleeding risk. Journal of Hospital Medicine 2014;9:579-585. © 2014 Society of Hospital Medicine.

Fast-track knee arthroplasty -- status and future challenges

BACKGROUND

Fast-track programs have been developed for different surgical procedures leading to higher patient satisfaction and lower morbidity. This concept has been extended to knee arthroplasty in recent years. The purpose of this narrative review was to discuss the different aspects of fast-track knee arthroplasty.

METHOD

Both authors searched the contemporary literature on minimally invasive knee arthroplasty and review articles on fast-track surgery aiming to summarize recent developments.

RESULTS

Length of stay after knee arthroplasty is influenced by preoperative risk factors, anaesthetic and surgical techniques, pain, orthostatic intolerance, cognitive function, sleep disturbances, bleeding and anaemia and finally muscle function and rehabilitation.

CONCLUSIONS

Fast-track surgery reduces the length of stay and the morbidity after knee arthroplasty.

CLINICAL RELEVANCE

Optimisation of pre-, per- and postoperative pathway for knee arthroplasty reduces morbidity after this type of surgery and results in shorter length of stay.

A systematic review of venous thromboembolism prophylaxis strategies in patients with renal insufficiency, obesity, or on antiplatelet agents

BACKGROUND

There is uncertainty about optimal strategies for venous thromboembolism (VTE) prophylaxis among select populations such as patients with renal insufficiency, obesity, or patients taking antiplatelet drugs including aspirin. Their physiologies make prophylaxis particularly challenging.

PURPOSE

We performed a comparative effectiveness review of the literature on efficacy and safety of VTE prophylaxis in these populations.

DATA SOURCES

We searched MEDLINE, EMBASE, SCOPUS, CINAHL, International Pharmaceutical Abstracts, clinicaltrial.gov, and the Cochrane Library through August 2012. Eligible studies included controlled trials and observational studies.

DATA EXTRACTION

Two reviewers evaluated studies for eligibility, serially abstracted data, and independently evaluated the risk of bias and strength of evidence supporting interventions to prevent VTE in these populations.

RESULTS

After a review of 30,902 citations, we identified 9 controlled studies, 5 of which were trials, and the other 4 were observational studies. Five articles addressed prophylaxis of patients with renal insufficiency, 2 addressed obese patients, and 2 addressed patients on antiplatelet agents. No study tested prophylaxis in underweight patients or those with liver disease. The majority of observational studies had a high risk of bias. The strength of evidence ranged from low to insufficient regarding the comparative effectiveness and safety of VTE prophylaxis among these patients.

CONCLUSION

The current evidence is insufficient regarding optimal VTE prophylaxis for patients with renal insufficiency, obesity, or those who are on antiplatelet drugs including aspirin. High-quality studies are needed to inform clinicians about the best VTE prophylaxis for these patients.