Mobile pump deep vein thrombosis prophylaxis: just say no to drugs

Ambulatory Portable Pneumatic Compression Device as Part of a Multimodal Aspirin-Based Approach in Prevention of Venous Thromboembolism in Outpatient Total Knee Arthroplasty

Background

The purpose of this study is to review the incidence of symptomatic venous thromboembolism (VTE) in patients undergoing outpatient primary total knee arthroplasty (TKA) who used a portable pneumatic compression device as part of their VTE prophylaxis protocol.

Methods

A retrospective review of all outpatient primary TKA procedures in which patients used ambulatory pneumatic compression pumps as part of their multimodal VTE prophylaxis was performed from 2016 through 2018. This yielded a cohort of 1131 patients (1453 TKAs). An aspirin (ASA)-based protocol was used in patients with standard VTE risk receiving either 81 mg or 325 mg of ASA twice daily for 6 weeks postoperatively. High-risk patients received a stronger chemoprophylaxis for 2 weeks followed by ASA for 4 weeks. Pneumatic compression pumps were worn for 23 hours/day for 14 days.

Results

VTE prophylaxis medication was 81-mg ASA in 56% of patients, 325-mg ASA in 10% of patients, and stronger chemoprophylaxis in 34% of patients. Patients were considered morbidly obese (body mass index >40 kg/m²) in 267 (18.4%) procedures. Ninety-seven (6.7%) patients had a preoperative history of VTE event. Forty-nine duplex ultrasounds were performed (3.3% of TKAs). Confirmed VTE events were documented in only 5 (0.3%) patients. All VTEs occurred in high-risk patients who were discharged on stronger chemoprophylaxis. The time (days) to VTE was 3, 3, 7, 45, and 88 days.

Conclusion

The use of portable pneumatic compression pumps as part of a multimodal VTE prophylaxis protocol aided in a very low rate of symptomatic VTE events in patients undergoing outpatient primary TKA.

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

INTRODUCTION

Current NICE Guidelines state that all patients undergoing total hip and knee arthroplasty should be given both mechanical and chemical prophylaxis. At our institution, a targeted thromboprophylaxis policy has been in place since October 1999. The aim of this study was to calculate our venous thromboembolism rates and compare these to published rates in the literature.

METHODS

All patients are pre-operatively assessed for their VTE risk. Patients are stratified into high or low risk: all patients received mechanical thromboprophylaxis and the higher risk patients now receive chemical and mechanical thromboprophylaxis post op. Patients are reviewed at 2, 6 and 52 weeks and with annual postal questionnaires and clinical and radiological review at 5 and 10yrs.

RESULTS

13,384 primary THA and TKAs were entered into the database. The overall rate of clinically apparent DVT and overall PE rates of 0.48% and 0.42% respectively. 86.16% of our patients were low risk, of these 23.3% of patients were on Aspirin/Clopidogrel with mechanical thromboprophylaxis and 76.7% of patients had mechanical prophylaxis alone. There was no statistical difference between the DVT or PE rates in the low risk groups.

CONCLUSION

Our results show that use of early mobilisation and mechanical prophylaxis within an Enhanced Recovery Programme results in comparable VTE rates to chemical prophylaxis for all, which is reflected in the literature. Our results question the need for chemical thromboprophylaxis or extended use of mechanical thromboprophylaxis in "lower risk" patients if a risk stratification policy is used in the context of modern surgical approaches.

Venous thromboembolic prophylaxis after simultaneous bilateral total knee arthroplasty: aspirin versus warfarin

Aims

The aims of this study were to compare the efficacy of two agents, aspirin and warfarin, for the prevention of venous thromboembolism (VTE) after simultaneous bilateral total knee arthroplasty (SBTKA), and to elucidate the risk of VTE conferred by this procedure compared with unilateral TKA (UTKA).

Patients and Methods

A retrospective, multi-institutional study was conducted on 18 951 patients, 3685 who underwent SBTKA and 15 266 who underwent UTKA, using aspirin or warfarin as VTE prophylaxis. Each patient was assigned an individualised baseline VTE risk score based on a system using the Nationwide Inpatient Sample. Symptomatic VTE, including pulmonary embolism (PE) and deep vein thrombosis (DVT), were identified in the first 90 days post-operatively. Statistical analyses were performed with logistic regression accounting for baseline VTE risk.

Results

The adjusted incidence of PE following SBTKA was 1.0% (95% confidence interval (CI) 0.86 to 1.2) with aspirin and 2.2% (95% CI 2.0 to 2.4) with warfarin. Similarly, the adjusted incidence of VTE following SBTKA was 1.6% (95% CI 1.1 to 2.3) with aspirin and 2.5% (95% CI 1.9 to 3.3) with warfarin. The risk of PE and VTE were reduced by 66% (odds ratio (OR) 0.44, 95% CI 0.25 to 0.78) and 38% (OR 0.62, 95% CI 0.38 to 1.0), respectively, using aspirin. In addition, the risk of PE was 204% higher for patients undergoing SBTKA relative to those undergoing UTKA. For each ten-point increase in baseline VTE risk, the risk of PE increased by 25.5% for patients undergoing SBTKA compared with 10.5% for those undergoing UTKA. Patients with a history of myocardial infarction or peripheral vascular disease had the greatest increase in risk from undergoing SBTKA instead of UTKA.

Conclusion

Aspirin is more effective than warfarin for the prevention of VTE following SBTKA, and serves as the more appropriate agent for VTE prophylaxis for patients in all risk categories. Furthermore, patients undergoing SBTKA are at a substantially increased risk of VTE, even more so for those with significant underlying risk factors. Patients should be informed about the risks associated with undergoing SBTKA.

Cite this article: Bone Joint J 2018;100-B(1 Supple A):68–75.