Tag Archive | heparin

VTE Prevention: Is Aspirin Really That Good?

OrthoBuzz occasionally receives posts from guest bloggers. In response to a three recent studiesthe following commentary comes from Jeffrey B. Stambough, MD.

Throughout the last decade, we’ve experienced a boom in anticoagulation options to help prevent venous thromboembolism (VTE) associated with orthopaedic procedures. The use of aggressive anticoagulation, such as warfarin and various heparin formulations, is being questioned, largely due to concerns about bleeding risks and wound complications.  Along with the newer direct oral anticoagulants such as rivaroxaban, over-the-counter aspirin (ASA) is gaining prominence as an anticoagulant due to its high efficacy, low cost, convenience for patients, favorable side-effect profile, and cardioprotective attributes.  Current guidelines include the use of all these thromboprophylactic agents, but three recent studies lend credence to using aspirin as the primary VTE prophylactic agent when performing total joint arthroplasty (TJA).

In a  March 20, 2019 JBJS study analyzing >31,000 TJAs performed at a single institution over 17 years, Rondon et al. found a 3-fold lower 30-day and 2-fold lower 1-year mortality rate in patients receiving ASA (81mg or 325 mg twice daily), compared to those who received non-aspirin thromboprophylaxis (mainly warfarin).  No mortality differences were noted between the two ASA dosing regimens.  While investigating specific causes of death, the authors discovered that the primary cause of death in the non-ASA cohort was cardiac related at all time points.

A second study, from the April 3, 2019 JBJS, looked into the effects of 3 antithrombotic agents on symptomatic VTE rates and periprosthetic infections in high-risk patients undergoing primary or revision TJA.  When compared to the two more potent agents (warfarin and low-molecular-weight heparin), ASA proved more effective at reducing pulmonary embolism (PE) and VTE rates in high-risk patients, and it was also associated with lower rates of periprosthetic joint infection when compared with warfarin.  Thus, it seems that even in patients deemed to be higher risk for developing VTE, ASA may be a safe, effective option.

Lastly, Runner et al. gleaned VTE prophylaxis data from >22,000 TJA cases submitted by surgeons sitting for Part 2 of ABOS between 2014 and 2016.  The findings, reported in the April 2019 issue of the Journal of Arthroplasty, showed similar trends to those seen in the two previously mentioned studies: Mild (distal or superficial deep vein thrombosis [DVT]), moderate (nonfatal PE, proximal DVT) and severe (fatal PE) VTE events, as well as death, were significantly less frequent in those who received ASA compared to more aggressive agents (heparin or one of its analogs, direct oral agents, or warfarin). Also, patients who received ASA with or without mechanical prophylaxis had significantly lower complication rates (95.5% vs. 93.0%, p<0.001).

One firmly held dogma in medicine is that patients who are at higher risk for VTE should be treated with stronger anticoagulation medications. However, these 3 studies support the idea that less aggressive anticoagulation medication (specifically, low-dose aspirin) may be the more effective and safer option for most patients. In our ongoing quest to improve patient outcomes and mitigate risk around the TJA episode, we should consider using aspirin for thromboprophylaxis unless there is an explicit contraindication in a specific patient.

However, we should also keep in mind that these three studies have the common limitations of all retrospective analyses. Recent randomized trials have shown aspirin to be “noninferior” to other anticoagulants for VTE prevention, and in less than 2 years, we should have even more definitive answers to this question from the randomized, multicenter PEPPER trial, with its estimated 25,000 participants.

Jeffrey B. Stambough, MD is an orthopaedic hip and knee surgeon, an assistant professor of orthopaedic surgery at University of Arkansas for Medical Sciences, and a member of the JBJS Social Media Advisory Board.

What’s New in Foot and Ankle Surgery

Foot xray for fott and ankle O'Buzz.jpegEvery month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.

This month, OrthoBuzz asked Sheldon Lin, MD, co-author of the April 19, 2017 Specialty Update on foot and ankle surgery, to select the five most clinically compelling findings from among the more than 50 studies cited in the article.

VTE Prevention

–Recommendations for venous thromboembolism (VTE) prophylaxis in isolated foot and ankle fractures are conflicting. In a prospective study, Zheng et al.1 determined the incidence of VTE in 814 patients who received either low-molecular-weight heparin or placebo for 2 weeks postoperatively. The overall incidence of deep vein thrombosis was 0.98% in the heparin group and 2.01% in the placebo group, with no significant difference between the two. The risk factors were high body mass index (BMI) and advanced age. The authors concluded that routine chemical prophylaxis was not necessary in cases of isolated foot and ankle fractures.

Age and Total Ankle Arthroplasty

–Concerns regarding implant survivorship in younger patients have prompted investigations into the effect of age on total ankle arthroplasty outcomes. Demetracopoulos et al.2 prospectively compared patient-reported outcomes and revision rates in patients who were 70 years of age. At the 3.5-year follow-up, patients who were 70 years of age, although no differences were observed in pain, need for reoperation, or revision rates between groups.

Hallux Rigidus/Hallux Valgus

–Joint-preserving arthroplasties for hallux rigidus have been proposed as an alternative to first metatarsophalangeal joint arthrodesis. However, they have shown high rates of failure with associated bone loss, rendering salvage arthrodesis a more complicated procedure with worse outcomes. A Level-I study by Baumhauer et al.3 investigated the use of a synthetic cartilage implant that requires less bone resection than a traditional arthroplasty. Patients were randomized to implant and arthrodesis groups. At the 2-year follow-up, pain level, functional scores, and rates of revision surgical procedures were statistically equivalent in both groups. Secondary arthrodesis was required in <10% of the implant group and was considered to be a straightforward procedure because of preservation of bone stock.

–Hallux valgus surgical procedures are commonly performed under spinal, epidural, or regional anesthesia. Although peripheral nerve blocks have become increasingly popular with the advent of ultrasound, the associated learning curve has limited more widespread use. A Level-I study by Karaarslan et al.4 compared the efficacy of ultrasound-guided popliteal sciatic nerve blocks with spinal anesthesia in patients undergoing hallux valgus correction. The popliteal block group demonstrated decreased pain scores at every time point up to 12 hours postoperatively, longer time to first analgesic requirement, and increased patient satisfaction scores compared with the spinal anesthesia group. The popliteal block group also did not experience the adverse effects of hypotension, bradycardia, and urinary retention occasionally seen with spinal anesthesia.

Orthobiologics

–Orthobiologics continue to generate considerable interest within the orthopaedic community. Platelet-rich plasma and hyaluronic acid have been investigated as adjuncts to promote healing. In a Level-I study, Görmeli et al.5 randomized patients to receive platelet-rich plasma, hyaluronic acid, or saline solution injections following arthroscopic debridement and microfracture of talar osteochondral lesions. At the intermediate-term follow-up, the platelet-rich plasma and hyaluronic acid groups exhibited a significant increase in AOFAS scores and decrease in pain scores compared with the control group, with the platelet-rich plasma group showing the greatest improvement.

References

  1. Zheng X, Li DY, Wangyang Y, Zhang XC, Guo KJ, Zhao FC, Pang Y, Chen YX. Effect of chemical thromboprophylaxis on the rate of venous thromboembolism after treatment of foot and ankle fractures. Foot Ankle Int. 2016 Nov;37(11):1218-24.
  2. Demetracopoulos CA, Adams SB Jr, Queen RM, DeOrio JK, Nunley JA 2nd, Easley ME. Effect of age on outcomes in total ankle arthroplasty. Foot Ankle Int. 2015 Aug;36(8):871-80.
  3. Baumhauer JF, Singh D, Glazebrook M, Blundell C, De Vries G, Le ILD Nielsen D, Pedersen ME, Sakellariou A, Solan M, Wansbrough G, Younger AS, Daniels T; for and on behalf of the CARTIVA Motion Study Group. Prospective, randomized, multi-centered clinical trial assessing safety and efficacy of a synthetic cartilage implant versus first metatarsophalangeal arthrodesis in advanced hallux rigidus. Foot Ankle Int. 2016 May;37(5):457-69.
  4. Karaarslan S, Tekg¨ul ZT, S¸ ims¸ek E, Turan M, Karaman Y, Kaya A, Gönüllü M. Comparison between ultrasonography-guided popliteal sciatic nerve block and spinal anesthesia for hallux valgus repair. Foot Ankle Int. 2016 Jan;37(1):85-9. Epub 2015 Aug 20.
  5. Görmeli G, Karakaplan M, Görmeli CA, Sarıkaya B, Elmalı N, Ersoy Y. Clinical effects of platelet-rich plasma and hyaluronic acid as an additional therapy for talar osteochondral lesions treated with microfracture surgery: a prospective randomized clinical trial. Foot Ankle Int. 2015 Aug;36(8):891-900.

JBJS Reviews Editor’s Choice–Orthopaedic Patients Taking Anticoagulants

Perioperative anticoagulation for patients undergoing orthopaedic surgery remains a challenge. Currently, there is insufficient evidence to provide definitive recommendations for care. Recent estimates suggest that, in the U.S. alone, there are over two million patients with atrial fibrillation who receive warfarin each year. Moreover, >100,000 heart valve replacements are performed annually.

In the September 2015 issue of JBJS Reviews, Dundon et al. review current recommendations for perioperative management of patients on existing anticoagulation therapy. They note that cessation of warfarin is based on risk stratification for thromboembolic events and bleeding risk, with cessation and bridging therapy being recommended if patients are at high risk for thromboembolic events or bleeding. On the basis of their assessment of published reports, they recommend that warfarin should be withdrawn and that bridging therapy should be instituted five days prior to surgery. Cessation and regular dosing should be resumed twelve to twenty-four hours after the operation.

However, the issue of perioperative bridging is currently under debate. The authors of this article could find no double-blind, randomized, controlled trials in which patients undergoing vitamin-K antagonist therapy who had received bridging with low-molecular-weight heparin or unfractionated heparin were compared with patients undergoing vitamin-K antagonist therapy who had received no bridging therapy. Bridging therapy with therapeutic-dose intravenous unfractionated heparin should be stopped four to six hours before surgery, but patients receiving therapeutic-dose subcutaneous low-molecular-weight heparin should take the last dose approximately twenty-four hours prior to surgery.

The authors recommended that patients in high cerebrovascular and cardiovascular risk groups should maintain aspirin with bridging therapy and may also maintain clopidogrel in emergencies as long as they are not undergoing a high-risk procedure. For patients who take rivaroxaban or dabigatran, emergency surgery is permissible as long as levels of the drug are ≤30 ng/mL at the time of admission.

These recommendations are based on careful and critical analyses of available data; however, as noted above, there are no critical evidence-based studies in the area of perioperative management of anticoagulation in patients who are undergoing orthopaedic surgery. The concepts and ideas presented in this article should be considered as recommendations at best.

Thomas Einhorn, Editor

JBJS Reviews