Thromboprophylaxis for orthopedic surgery; An updated meta-analysis

Appraisal of the clinical practice guidelines on thromboprophylaxis in orthopaedic procedures; Do we AGREE (II)?

OBJECTIVE

Optimal thromboprophylaxis in orthopaedic procedures is crucial in an attempt to lower the risk of venous thromboembolism, including deep vein thrombosis and pulmonary embolism. We aim to: 1) identify clinical practice guidelines (CPGs) and recommendations (CPRs) on thromboprophylaxis in adult patients undergoing orthopaedic procedures, and 2) assess the methodological quality and reporting clarity of these guidelines.

METHODS

The study was conducted following the 2020 PRISMA guidelines for a systematic review and has been registered on the international prospective register of systematic reviews (PROSPERO) under the registration number (CRD42023406988). An electronic search was conducted using Medline, Embase, Cochrane, Web of Science, Google Scholar and medRxiv. The search terms used were ""adults", "orthopedic surgery", "orthopedic surgeries", "orthopedic surgical procedure", "orthopedic surgical procedures" "english language", "venous thromboembolism", in all possible combinations (January 2013 to March 2023). The eligible studies were evaluated by four blind raters, employing the Appraisal of Guidelines for Research & Evaluation II (AGREE-II) analysis tool.

RESULTS

The literature research resulted in 931 studies. Finally, a total of 16 sets of guidelines were included in the current analysis. There were 8 national and 8 international CPGs. Eight CPGs made specific recommendations for orthopaedic surgery and referred mostly to joints; one guideline focused on pelvi-acetabular trauma, while the rest were more inclusive and non-specific. Four guidelines, one from the American Society of Hematology (ASH), two from the United Kingdom (UK) and one from India were found to have the highest methodological quality and reporting clarity according to the AGREE-II tool. Inter-rater agreement was very good with a mean Cohens Kappa 0.962 (95 % CI, 0.895-0.986) in the current analysis. So, the reliability of the measurements can be interpreted as good to excellent.

CONCLUSION

Optimal thromboprophylaxis in orthopaedic procedures is crucial. The available guidelines were found to be mostly of high methodological quality and inter-rater agreement was very good, according to our study.

Incidence of deep venous thrombosis in patients with hemophilia undergoing bilateral simultaneous total knee arthroplasty: a retrospective cohort study

BACKGROUND

Hemophilic arthropathy usually affects the knees bilaterally. In order to reduce costs and improve rehabilitation, bilateral simultaneous total knee arthroplasty (TKA) can be performed. However, pharmacological prophylaxis for deep venous thrombosis (DVT) remains controversial in patients with severe hemophilia. The purpose of this study was to establish the incidence of DVT in severe hemophilia A patients undergoing bilateral simultaneous TKA without pharmacological thromboprophylaxis.

METHODS

Consecutive patients with severe hemophilia A undergoing bilateral simultaneous TKA at a single center between January 2015 and December 2020 were retrospectively reviewed. All patients received a modified coagulation factor substitution regimen. Tranexamic acid (TXA) was used for hemostasis in all patients during surgery. All patients followed a standardized postoperative protocol with routine mechanical thromboprophylaxis, and none received anticoagulation. D-dimer was measured preoperatively, on the day of the operation and on postoperative days 1, 7 and 14. Ultrasound (US) of the lower extremities was performed before (within 3 days of hospitalization) and after surgery (days 3 and 14) to detect asymptomatic DVT. Patients were followed up until 2 years after surgery for the development of symptomatic DVT or pulmonary embolism (PE).

RESULTS

38 male patients with severe hemophilia A underwent 76 simultaneous TKAs. Mean (± standard deviation) age at the time of operation was 41.7 (± 17.1) years. Overall, 47.3% of patients had D-dimer concentrations above the threshold 10 µg/mL on day 7 and 39.5% on day 14. However, none of the patients had DVT detected on postoperative US, nor developed symptomatic DVT or PE during the 2-year follow-up.

CONCLUSIONS

The risk of DVT in patients with severe hemophilia A after bilateral simultaneous TKA is relatively low, and routine pharmacological thromboprophylaxis may not be needed.

Pharmacological Thromboprophylaxis in People with Hemophilia Experiencing Orthopedic Surgery: What Does the Literature Say in 2023?

This narrative review of the literature, consisting of papers found in PubMed and The Cochrane Library published up to 31 July 2023, analyzed those that were deemed to be closely related to the title of this paper. It was encountered that the peril of deep vein thrombosis (DVT) in people with hemophilia (PWH) after orthopedic surgery is very small, such that pharmacological thromboprophylaxis is not necessary in most cases. The hemophilia literature states that the use of pharmacological thromboprophylaxis should only be performed in PWH undergoing major orthopedic surgery (total-knee arthroplasty, total-hip arthroplasty, ankle arthrodesis) who have additional venous thromboembolism (VTE) risk factors, such as old age, prior VTE, varicose veins, general anesthesia, cancer, factor V (Leiden) mutation, overweight, and treatment with the oral contraceptive pill (in females with von Willebrand's illness). If we notice various risk factors for VTE in PWH who experience orthopedic surgery, theoretically, we should perform the identical type of pharmacological thromboprophylaxis advised for non-hemophilia patients: low-molecular weight heparins (LMWHs), such as enoxaparin (40 mg subcutaneous/24 h); or direct oral anticoagulants (DOACs), either thrombin inhibitors (dabigatran, 150 mg oral/12 h) or activated factor X (FXa) inhibitors (rivaroxaban, 20 mg oral/24 h; apixaban, 5 mg oral/24 h), or subcutaneous fondaparinux (2.5 mg/24 h subcutaneously). However, the review of the literature on hemophiliac patients has shown that only a few authors have used pharmacological prophylaxis with LMWH (subcutaneous enoxaparin) for a short period of time (10-14 days) in some patients who had risk factors for VTE. Only one group of authors used a low dose of DOAC in the dusk after the surgical procedure and the next day, specifically in individuals at elevated risk of VTE and elevated risk of bleeding after the surgical procedure.

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.

Direct Oral Anticoagulants: How Do These Drugs Work, How to Monitor, and What Is Their Role in Orthopaedic Surgery

Postoperative venous thromboembolism is a major adverse event associated with orthopaedic surgery. With the addition of perioperative anticoagulation and antiplatelet therapy, the rates of symptomatic venous thromboembolism have dropped to 1% to 3%, and as such, practicing orthopaedic surgeons must be familiar with these medications, including aspirin, heparin, or warfarin, and the use of direct oral anticoagulants (DOACs). DOACs are increasingly being prescribed due to their predictable pharmacokinetics and increased convenience, as they do not require routine monitoring, and 1% to 2% of the general population is currently anticoagulated. Although the introduction of DOACs has yielded additional treatment options, this has also led to confusion and uncertainty regarding treatment, specialized testing, and when and what reversal agents are appropriate. This article provides a basic overview of DOAC medications, their suggested use in the perioperative setting, effects on laboratory testing, and consideration for when and how to use reversal agents in orthopaedic patients.

Thromboembolic Disease in Haemophilic Patients Undergoing Major Orthopaedic Surgery: Is Thromboprophylaxis Mandatory?

Haemophilia is a rare genetic disorder, that results from various degrees of deficiency of coagulation factor VIII (haemophilia A), or factor IX (haemophilia B), with an X-linked transmission. The patients affected are in the majority of cases males (who inherit the affected X-chromosome from the maternal side), with rare cases of females with haemophilia (FVIII or FIX < 40 IU/dL), situations in which both X-chromosomes are affected, or one is affected, and the other one is inactive (known as carrier). The hypocoagulable state due to the deficiency of clotting factors, manifests as an excessive, recurrent tendency to bleeding, which positively correlates with plasmatic levels. Severe haemophilia results in hemarthrosis, although recent data have shown that moderate or even mild disease can lead to joint bleeding. Recurrent episodes of haemorrhages, usually affecting large joints such as knees, elbows, or ankles, lead to joint remodelling and subsequent haemophilic arthropathy, which may require arthroplasty as a last therapeutic option. Orthopaedic patients have the highest risk among all for deep vein thrombosis (DVT) and venous thromboembolism (VTE) with morbid and potentially fatal consequences. While for the rest of the population thromboprophylaxis in orthopaedic surgery is efficient, relatively safe, and widely used, for patients with haemophilia who are considered to have a low thromboembolic risk, there is great controversy. The great heterogeneity of this particular population, and the lack of clinical trials, with only case reports or observational studies, makes thromboprophylaxis in major orthopaedic surgery a tool to be used by every clinician based on experience and case particularities. This review aims to briefly summarise the latest clinical data and to offer an insight into the current recommendations that readers would find useful in daily practice.

"In Less than No Time": Feasibility of Rotational Thromboelastometry to Detect Anticoagulant Drugs Activity and to Guide Reversal Therapy

Anticoagulant drugs (i.e., unfractionated heparin, low-molecular-weight heparins, vitamin K antagonists, and direct oral anticoagulants) are widely employed in preventing and treating venous thromboembolism (VTE), in preventing arterial thromboembolism in nonvalvular atrial fibrillation (NVAF), and in treating acute coronary diseases early. In certain situations, such as bleeding, urgent invasive procedures, and surgical settings, the evaluation of anticoagulant levels and the monitoring of reversal therapy appear essential. Standard coagulation tests (i.e., activated partial thromboplastin time (aPTT) and prothrombin time (PT)) can be normal, and the turnaround time can be long. While the role of viscoelastic hemostatic assays (VHAs), such as rotational thromboelastometry (ROTEM), has successfully increased over the years in the management of bleeding and thrombotic complications, its usefulness in detecting anticoagulants and their reversal still appears unclear.

Enoxaparin Versus Direct Oral Anticoagulants for Venous Thromboembolism in Asians Undergoing Total Knee Arthroplasty: A Meta-Analysis and Systematic Review

BACKGROUND

The introduction of direct oral anticoagulants (DOACs) shows promise for their role as a chemoprophylaxis agent after total knee arthroplasty (TKA) for the prevention of venous thromboembolism (VTE). However, existing studies are largely based on Western populations that do not account for the different risk profiles and lower rates of VTE in Asians. This systematic review and meta-analysis aimed to evaluate the efficacy of DOACs compared with enoxaparin in an Asian-based population study.

METHODS

The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. All studies that compared outcomes between enoxaparin and DOACs as VTE prophylaxis after TKA in the Asian population were included.

RESULTS

Five studies with 121,153 patients were included. DOACs demonstrated a convincing benefit over enoxaparin in overall VTE prevention (odds ratio [OR] = 0.42, 95% confidence interval [CI]: 0.24-0.74). However, although the OR trended in favor of DOACs for the reduction of deep vein thrombosis events (OR = 0.54, 95% CI: 0.20-1.48) and pulmonary embolism (OR = 0.75, 95% CI: 0.07-8.20), statistical significance was not reached. In terms of bleeding complications, both arms had similar rates of major (0.91% vs 0.20%), clinically relevant nonmajor (3.28% vs 2.94%), and minor bleeding complications (12.8 vs 13.3%). A nonsignificance advantage of enoxaparin over DOACs was revealed in the OR for major bleeding (OR = 3.17; 95% CI: 0.81-12.43), whereas DOACs were favored to reduce risk of clinically relevant nonmajor (OR = 0.82; 95% CI: 0.01-91.51) and minor bleeding (OR = 0.76; 95% CI: 0.11-5.33).

CONCLUSION

DOACs confer a significantly reduced rate of overall VTE compared with enoxaparin in Asians after TKA. No significant differences in deep vein thrombosis, pulmonary embolism, and rates of bleeding complications exist.