Fatal pulmonary embolism following elective total knee replacement using aspirin in multi-modal prophylaxis - A 12year study

A Comparison of the Caprini Score With an Institutional Risk Assessment Tool for Prediction of Venous Thromboembolism After Total Joint Arthroplasty at an Urban Tertiary Care Health Safety Net Hospital

Background

Patients undergoing total joint arthroplasty (TJA) are at increased risk for venous thromboembolism (VTE). Prediction tools such as the Caprini Risk Assessment Model (RAM) have been developed to identify patients at higher risk. However, studies have reported heterogeneous results when assessing its efficacy for TJA. Patients treated in an urban health safety net hospital have increased medical complexity, advanced degenerative joint disease, and severe disability prior to TJA increasing the risk of VTE. We hypothesize that use of a tool designed to account for these conditions-the Boston Medical Center (BMC) VTE score-will more accurately predict VTE in this patient population.

Methods

A retrospective case-control study was performed including subjects 18 years of age and older who underwent primary or revision TJA in an urban academic health safety net hospital. Patients with hemiarthroplasties, simultaneous bilateral TJA, and TJA after acute trauma were excluded. A total of 80 subjects were included: 40 who developed VTE after TJA (VTE+) and 40 who did not develop VTE (controls). Subjects were matched by age, gender, and surgical procedure.

Results

There was a statistically significant difference between the mean BMC VTE score for VTE+ and controls (4.40 and 3.13, respectively, P = .036). Conversely, there was no statistical difference between the mean Caprini scores for VTE+ and controls (9.50 and 9.35, respectively, P = .797).

Conclusions

In a health safety-net patient population, an institutional RAM-the BMC VTE score-was found to be more predictive of VTE than the modified Caprini RAM following TJA. The BMC-VTE score should be externally validated to confirm its reliability in VTE prediction in similar patient populations.

The use of pre-operative Inferior Vena Cava filters for thromboprophylaxis in ultra-high-risk patients undergoing total hip and knee arthroplasty: a systematic review and narrative analysis

PURPOSE

Patients undergoing total hip (THA) or knee (TKA) arthroplasty are at high risk of venous thromboembolism (VTE). As the number performed annually increases, the population at risk of fatal pulmonary embolism (PE) also grows. Ultra-high-risk arthroplasty patients (UHRAPs) include those with additional comorbidities, or a history of VTE, for many of whom routine prophylaxis will previously have failed. Pre-operative insertion of Inferior Vena Cava filters (IVCFs) has been recommended for thromboprophylaxis in UHRAPs, and this review was performed to establish their results.

METHODS

A systematic search of MEDLINE and Embase databases was performed for studies reporting the use of Inferior Vena Cava filters in hip and knee arthroplasty patients.

RESULTS

Ten studies met the inclusion criteria, containing 718 IVCFs in Orthopaedic patients, 343 of which were permanent (47.8%), 369 potentially retrievable (51.4%), 5 absorbable (0.6%) and one of unknown design (0.1%). Patient age averaged 64.7yrs (17-95) and 56% were female. Pre-operatively, 415 prophylactic IVCFs were inserted in 409 UHRAPs, undergoing a total of 438 total joint arthroplasties (TJA). There were 11 cases of PE in the entire series (1.5%) only one of which was fatal (0.01%), with four non-fatal PE in the UHRAP group (0.96%). Removal was attempted for 283 of the retrievable filters (76.7%) and was successful in 280 (98.9%).

CONCLUSION

The use of IVCFs eliminated fatal PE in UHRAPs, but larger, high-quality studies, with standardised reporting, are still required to determine their absolute indications for use, complication profile, efficacy and optimum design.

Low-Dose Aspirin Is Safe and Effective for Venous Thromboembolism Prophylaxis Following Total Knee Arthroplasty

BACKGROUND

Aspirin is an effective prophylaxis for venous thromboembolism (VTE) after total knee arthroplasty (TKA). The optimal prophylactic aspirin dose has not been established. The study aims to compare 2 aspirin regimens with regard to the incidence of (1) symptomatic deep venous thrombosis (DVT), (2) pulmonary embolism (PE), (3) bleeding, and (4) mortality within 90 days after TKA.

METHODS

We retrospectively identified 5666 patients who received aspirin twice daily for 4 to 6 weeks after TKA. A total of 1327 patients received 81-mg BID and 4339 patients received 325-mg BID aspirin. Postoperative complications collected were VTEs (DVT and PE), bleeding (gastrointestinal or wound bleeding), and mortality.

RESULTS

The incidence of VTE was 1.5% in the 325-mg group and 0.7% in the 81-mg group (P = .02). Symptomatic DVT was 1.4% in the 325-mg aspirin compared with 0.3% for the 81-mg aspirin (P = .0009). Regression model showed no correlation between aspirin dose and VTE incidence (odds ratio [OR] = 1.03; 95% confidence interval [95% CI], 0.45-2.36; P = .94) or DVT (OR = 0.50; 95% CI, 0.16-1.55; P = .20). The incidence of PE was 0.2% in the high-aspirin group compared with 0.4% in the low-aspirin group (P = .13). Bleeding was 0.2% in the 325-mg aspirin group and 0.2% in the 81-mg aspirin group (P = .62), and 90-day mortality was similar (0.1%) between the groups (P = .56).

CONCLUSION

Low-dose aspirin was not inferior to high-dose aspirin for the prevention of VTE after TKA. Low-dose aspirin can be considered a safe and effective agent in the prevention of VTE after TKA.