Prevention of Deep Venous Thromboembolism in Foot and Ankle Surgery

Using machine learning in the prediction of symptomatic venous thromboembolism following ankle fracture

BACKGROUND

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in the trauma setting, and both prediction and prevention of VTE have long been a concern for healthcare providers in orthopedic surgery. The purpose of this study was to evaluate the use of novel statistical analysis and machine-learning in predicting the risk of VTE and the usefulness of prophylaxis following ankle fractures.

METHODS

The medical profiles of 16,421 patients with ankle fractures were screened retrospectively for symptomatic VTE. In total, 238 patients sustaining either surgical or nonsurgical treatment for ankle fracture with subsequently confirmed VTE within 180 days following the injury were placed in the case group. Alternatively, 937 patients who sustained ankle fractures managed similarly but had no documented evidence of VTE were randomly chosen as the control group. Individuals from both the case and control populations were also divided into those who had received VTE prophylaxis and those who had not. Over 110 variables were included. Conventional statistics and machine learning methods were used for data analysis.

RESULTS

Patients who had a motor vehicle accident, surgical treatment, increased hospital stay, and were on warfarin were shown to have a higher incidence of VTE, whereas patients who were on statins had a lower incidence of VTE. The highest Area Under the Receiver Operating Characteristic Curves (AUROC) showing the performance of our machine learning approach was 0.88 with 0.94 sensitivity and 0.36 specificity. The most balanced performance was seen in a model that was trained using selected variables with 0.86 AUROC, 0.75 sensitivity, and 0.85 specificity.

CONCLUSION

By using machine learning, this study successfully pinpointed several predictive factors linked to the occurrence or absence of VTE in patients who experienced an ankle fracture. Training these algorithms using larger, more granular, and multicentric data will further increase their validity and reliability and should be considered the standard for the development of such algorithms.

LEVEL OF EVIDENCE

Case-Control study - 3.

Venous Thromboembolism Prophylaxis in Foot and Ankle Surgery: A Worldwide Survey

Current recommendations on thromboprophylaxis for foot and ankle (FA) surgery are often inconsistent and generally based on weak evidence. The aim of this survey study was to evaluate the current practice among orthopedic surgeons regarding venous thromboembolism (VTE) prophylaxis following FA surgery. From February 2019 to March 2020, an online questionnaire was sent by e-mail to orthopedic societies across the world. The questionnaire was hosted by the International Society of Thrombosis and Haemostais RedCAP platform. Topics of interest were VTE rates following FA surgery, duration and type of thromboprophylaxis, bleeding complications, VTE risk factors for prophylaxis and use of risk assessment. A total of 693 FA orthopedic surgeons from all continents completed the survey of whom 392 (57%) performed more than 200 FA procedures per year. A total of 669/693 (97%) respondents stated that thromboprophylaxis is necessary in FA surgeries. When thromboprophylaxis was prescribed, half of surgeons prescribed it for the duration of immobilization. Acetylsalicylic acid, low molecular weight heparin and direct-oral anticoagulants were, in this order, the preferred choice. Acetylsalicylic acid and low molecular weight heparin were predominantly prescribed in North America and Europe, respectively. Previous deep vein thrombosis, immobility, obesity and inherited thrombophilia were considered the main risk factors indicative of thromboprophylaxis use. In this survey, most surgeons agree that thromboprophylaxis is indicated for FA surgery, but the prescription, type and duration of prophylaxis differs greatly with a large intercontinental discrepancy. These survey results could be a foundation for developing uniform guidelines to optimize thromboprophylactic strategies in FA procedures around the world.

Mechanical Thromboprophylaxis Alone in Body Contouring Surgery for Post Massive Weight Loss Patients: Is this Good Enough?

BACKGROUND

Although the use of pharmacological thromboprophylaxis effectively reduces Deep vein thrombosis (DVT) incidence after body contouring surgery, this might increase the risk of bleeding and hematoma formation. In this scenario, the use of mechanical prophylaxis alone could be an attractive alternative. We aimed to evaluate the incidence of DVT in patients with massive weight loss undergoing body contouring surgeries in whom mechanical prophylaxis alone was indicated.

METHODS

This retrospective cohort study included all patients who underwent body contouring surgery after massive weight loss between 09/01/16-12/31/19 and received solely mechanical prophylaxis of VTD. Data collected included smoking habit, body mass index, history of cancer, use of contraceptives, magnitude of weight loss, Caprini scale, American society of anesthesiology physical status (ASA-PS) classification, and type and length of procedures. An analysis of DVT events during the postoperative period up to 90 days was undertaken.

RESULTS

Sixty-four patients, in whom 82 BCS were performed, were included in this study. Most of them (89.1%) were female with a mean age of 47 ± 12 years. Mechanical prophylaxis methods used were elastic compression stockings, intermittent pneumatic compression boots, and early deambulation. In all cases, the average length of hospital stay was 26.3 ± 9.6 hours. Surgical times were less than 155,7 minutes in all procedures. Global incidence of DVT was 1.2% in a patient receiving mechanical prophylaxis alone. There were no bleeding complications or pulmonary embolism episodes.

CONCLUSIONS

In this series, DVT incidence in patients with mechanical prophylaxis alone was deemed acceptable if compared to the incidence reported in the literature. Individualization of the risk of thrombosis and bleeding in this group of patients is of paramount importance to reduce complications.

LEVEL OF EVIDENCE IV

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Prophylaxis of Venous Thromboembolism in Ankle and Foot Surgeries

Venous thromboembolism (VTE) is among the most feared complications by orthopedists both for due to its potentially lethal outcome and the uncertainties related to its prevention. Despite the vast literature on VTE prevention in major orthopedic surgeries, little is known about it in ankle and foot procedures. In orthopedics, adequate thromboprophylaxis requires a careful assessment of the thrombotic and hemorrhagic risks based on the procedure to be performed, as well as and knowledge on anticoagulant agents. The presentis review has the goal of assessing the risk of developingdiscusses VTE risk assessment, the modalities of thromboprophylaxis modalities, and the drugs used, with an emphasis on foot and ankle surgeries.