Detection Of Deep Venous Thrombosis Research Articles

Predicting Deep Venous Thrombosis Using Artificial Intelligence: A Clinical Data Approach

Deep venous thrombosis is a critical medical condition that occurs when a blood clot forms in a deep vein, usually in the legs, and can lead to life-threatening complications such as pulmonary embolism if not detected early. Hospitalized patients, especially those with immobility or post-surgical recovery, are at higher risk of developing deep venous thrombosis, making early prediction and intervention vital for preventing severe outcomes. In this study, we evaluated the following eight machine learning models to predict deep venous thrombosis risk: logistic regression, random forest, XGBoost, artificial neural networks, k-nearest neighbors, gradient boosting, CatBoost, and LightGBM. These models were rigorously tested using key metrics, including accuracy, precision, recall, F1-score, specificity, and receiver operating characteristic curve, to determine their effectiveness in clinical prediction. Logistic regression emerged as the top-performing model, delivering high accuracy and an outstanding receiver operating characteristic curve score, which reflects its strong ability to distinguish between patients with and without deep venous thrombosis. Most importantly, the model’s high recall underscores its ability to identify nearly all true deep venous thrombosis cases, significantly reducing the risk of false negatives—a critical concern in clinical settings, where delayed or missed diagnoses can result in life-threatening complications. Although models such as random forest and eXtreme Gradient Boosting also demonstrated competitive performances, logistic regression proved the most reliable across all metrics. These results suggest that machine learning models, particularly logistic regression, have great potential for early deep venous thrombosis detection, enabling timely clinical interventions and improved patient outcomes.

Diagnostic value of fibrinogen in lower extremity deep vein thrombosis caused by rib fracture: A retrospective study.

Objectives: To investigate the diagnostic value of fibrinogen (FIB) in patients with rib fractures complicated by lower extremity deep venous thrombosis (DVT).Methods: Analyzing data from 493 patients at Shijiazhuang Third Hospital, FIB levels at 24, 48, and 72h post-injury were compared between DVT and non-DVT groups.Results: DVT group had elevated FIB levels at all times (p < .001). FIB at 24h showed highest AUC, particularly in patients with BMI <28.Conclusion: In conclusion, measuring FIB at 24h post-injury enhances DVT detection in rib fracture patients, with potential BMI-related variations.

Analysis of D-dimer levels for the detection of deep venous thrombosis for patients with spinal metastasis undergoing decompression with fixation

BackgroundDeep venous thrombosis (DVT) after spinal surgery has recently attracted increasing attention. Patients with spinal metastases who undergo decompression with fixation are at a high risk of developing DVT. D-dimer levels indicate the risk of DVT, and the purpose of our study was to investigate D-dimer levels as a predictor of DVT perioperatively.MethodsWe prospectively evaluated 100 patients with spinal metastases. D-dimer tests were performed twice: once before surgery and one day postoperatively. DVT was diagnosed by duplex ultrasonographic assessment of both lower extremities. Pulmonary embolisms (PEs) were diagnosed using multidetector computed tomography and pulmonary angiography. Perioperative serum D-dimer levels were compared between the DVT (+) and DVT (-) groups. The cutoff value of the D-dimer level was calculated using receiver operating characteristic analysis.ResultsPreoperative and postoperative DVT prevalences were 8.0% (8/100) and 6.6% (6/91), respectively, and none of the patients developed PE. Before surgery, there was no significant differences in D-dimer levels between the pre-DVT (+) and pre-DVT (-) groups. After surgery, the D-dimer level one-day postoperatively for the post-DVT (+) group (17.6 ± 11.8 mg/L) was significantly higher than that of the post-DVT (-) group (5.0 ± 4.7 mg/L). The cutoff value of the postoperative D-dimer level was 9.51(mg/L), and the sensitivity and specificity for the optimum threshold were 83.3% and 89.4%, respectively.ConclusionsOur findings suggest that preoperative D-dimer level may not be a predictor of DVT. Preoperative ultrasound examinations should be routinely performed in patients with spinal metastases. Postoperative D-dimer levels greater than 9.51(mg/L) are a predictive factor for the early diagnosis of DVT after spine surgery.Trial registrationOur study was registered on Chinese Clinical Trial Registry (No.ChiCTR2000029737). Registered 11 February 2020 - Retrospectively registered, https://www.chictr.org.cn/index.aspx.

Incidental deep venous thrombosis diagnosed on lower extremity computed tomography is a rare but clinically impactful finding

BackgroundIn the setting of a known thrombotic event, computed tomography (CT) studies provide reasonable sensitivity for the diagnosis of deep venous thrombosis (DVT). However, the incidence and accuracy of a DVT diagnosis on CT studies not targeted for the detection of DVT are not well described. In addition, the clinical impact of DVTs incidentally identified on CT is unknown. MethodsIn this single-institution retrospective study, we queried all contrasted CT studies of the lower extremities performed over a 10-year period. Regular expressions applied to the radiology reports associated with the CT studies identified studies with positive findings associated with DVT. These selected reports were then manually reviewed to confirm the presence of a DVT. Patient demographics and relevant medical and surgical history were obtained through a chart review. Follow-up information was obtained for 1 year after the incident CT and included treatment course, additional imaging, and adverse events. An incidental DVT was one identified in a patient in whom the DVT was not noted in a prior study and for whom the study indication did not include concern for DVT or pulmonary embolism. ResultsOf 16,637 lower extremity contrasted CT studies queried, 37 study reports identified a DVT. However, only 13 patients had a finding of an incidental DVT (10-year incidence of 0.08%). Among these 13 patients, 11 underwent additional imaging, including 9 who had a subsequent venous duplex and 2 who had subsequent CT studies. Among those with a subsequent duplex, DVT was not identified in eight cases, whereas in one case, DVT was confirmed. Among those with subsequent CT studies, DVT was not identified in one case and was confirmed in one case. Of the 13 patients with incidental DVTs, 3 were initiated on anticoagulation based on their initial CT findings alone. Among these, two did not experience any complications from their DVT or anticoagulation regimen. One did experience major bleeding complications, requiring additional procedures. ConclusionsIncidental DVTs are a rare finding in lower extremity CT studies, noted to occur in only 0.08% of studies. Most patients with incidental DVTs receive additional imaging, with negative findings in 80% of cases. This study identified that 23% of patients were initiated on anticoagulation due to the CT findings, with a 33% rate of significant complications. Currently, a CT venogram is not recommended as a first-line modality for the diagnosis of DVT. However, there is no guidance regarding the need for repeat imaging in patients with incidentally diagnosed lower extremity DVTs identified on CT. Additional study is needed to provide evidence for guideline development.

Geriatrician-Performed Point-of-Care Ultrasound for Detection of Deep Venous Thrombosis in Geriatric Inpatients - A Proof of Concept Study

This study was conducted as a single-center feasibility study. Patients with suspicion of deep venous thrombosis defined as Well's score of 0-1 with a concomitant elevated D-dimer or a Well's score ≥ 2 regardless of D-dimer were eligible for inclusion. In addition, the following inclusion criteria were met: 1) ≥ 65 years, and 2) presence of ≥ 2 diseases. No current DVT diagnosis or targeted treatment against DVT. Patients first underwent ultrasound examination by a geriatrician and subsequently by a blinded radiologist.

Artificial intelligence-based iliofemoral deep venous thrombosis detection using a clinical approach

Early diagnosis of deep venous thrombosis is essential for reducing complications, such as recurrent pulmonary embolism and venous thromboembolism. There are numerous studies on enhancing efficiency of computer-aided diagnosis, but clinical diagnostic approaches have never been considered. In this study, we evaluated the performance of an artificial intelligence (AI) algorithm in the detection of iliofemoral deep venous thrombosis on computed tomography angiography of the lower extremities to investigate the effectiveness of using the clinical approach during the feature extraction process of the AI algorithm. To investigate the effectiveness of the proposed method, we created synthesized images to consider practical diagnostic procedures and applied them to the convolutional neural network-based RetinaNet model. We compared and analyzed the performances based on the model’s backbone and data. The performance of the model was as follows: ResNet50: sensitivity = 0.843 (± 0.037), false positives per image = 0.608 (± 0.139); ResNet152 backbone: sensitivity = 0.839 (± 0.031), false positives per image = 0.503 (± 0.079). The results demonstrated the effectiveness of the suggested method in using computed tomography angiography of the lower extremities, and improving the reporting efficiency of the critical iliofemoral deep venous thrombosis cases.

Accuracy of point-of-care tele-ultrasonography for assisting ultrasound-naive resident doctors in detecting lower-limb deep venous thrombosis: A prospective controlled trial

ObjectivesThis study aimed to explore the accuracy of point-of-care tele-ultrasonography (POC-TUS) in detecting lower-limb deep venous thrombosis (DVT). MethodsWe conducted a prospective study in the intensive care unit (ICU). Each patient underwent three sessions of POC-US by one US-naive resident doctor (Group 1), one resident doctor supervised by a remote experienced radiologist through real-time POC-TUS (Group 2), and one on-site experienced radiologist (Group 3). The presence and location (if any) of lower limb DVT and the duration of examination of each patient were recorded. Diagnostic accuracy was determined by the consensus of two independent observers. ResultsFinally, 71 patients (39.4%, 71/180) with lower limb DVT were identified. The accuracy of Group 2 was similar to that of Group 3 (91.7% vs. 92.8%, P = 0.694) but significantly higher than that of Group 1 (91.7% vs. 72.8%, P < 0.001). The median duration of examination of Group 2 (7 min) was shorter than that of Group 1 (11 min) (P < 0.001) and longer than that of Group 3 (4 min) (P < 0.001). ConclusionResident doctors can promptly and accurately detect lower-limb DVT in patients in the ICU with real-time POC-TUS guidance. SignificanceLower-limb DVT is the most common cause of pulmonary embolism and may result in substantial morbidity and mortality, and its early and accurate detection is crucial. This study is among the few to provide evidence for the usefulness of real-time POC-TUS early and accurate detection of lower-limb DVT.

Appearance and Frequency of Deep Venous Thrombosis After Total Hip Arthroplasty.

Postoperative venous thromboembolism is an important peri-operative complication associated with total hip arthroplasty (THA). In particular, early detection of deep venous thrombosis (DVT) is important for the prevention of pulmonary embolism (PE). However, the methods and timing of examinations for DVT detection differ among the facilities. This study aimed to clarify the time, site, and frequency of DVT after THA. Background characteristics including age, sex, body mass index, diagnosis, operation type, operation time, and anesthesia type were investigated in 348 patients who underwent THA at our hospital between April 2017 and April 2019. Blood tests were performed preoperatively and on postoperative days (POD) 0, 1, 3, 7, 14, and 21. Simultaneously, vascular ultrasonography was performed to investigate the time and site of thrombus occurrence before and after the surgery. DVT was observed in 27.2% of the patients on POD 21. The DVT-positive ratio was 9.4% (6/64) in males and 31.3% (89/284) in females. There was a significant difference between the groups (p = 0.0002). Patients in the DVT-positive group were significantly older than those in the DVT-negative group (73.0 ± 7.9 years vs. 63.3 ± 11.2 years, p = 0.0041). DVT mainly occurred in the soleal vein (74.7%). However, there was no significant difference between the operated and non-operated sides. In the DVT-positive group, thrombus occurred in 13.3% of preoperative cases, 20.0% on POD 0, 46.7% on POD 1, 13.3% on POD 3, 6.7% on POD 7, and 0% on POD 14 and 21. Vascular ultrasonography showed that thrombus occurred most frequently in the soleal vein. Thrombus occurred in 66.6% of DVT-positive patients by POD 1, indicating that thrombus appeared very early after surgery. All thrombus cases were formed by POD 7.

Comparison of gray scale versus Doppler ultrasound to detect deep venous thrombosis in lower extremities.

Objectives: The objective was to determine the accuracy of Gray Scale versus Doppler Ultrasound to Detect Deep Venous Thrombosis in Lower Extremities. Study Design: Cross Sectional Analytical study. Setting: The University of Lahore and Shalimar Hospital Lahore. Period: May to October 2020. Material &amp; Methods: After a permission from the ethical committee and a written consent of the patients, on the basis of the clinical suspicions of deep vein thrombosis, A total of 140 patients of both the genders, aging from 20 to 90 years, were referred for Gray Scale &amp; Doppler ultrasound examination. The convenient sampling technique and Statistical software for social sciences (SPSS version 22.0) were used for the analysis of data. Results: In 140 patients’ present study on Gray Scale ultrasound, 120 (85%) cases were observed with significantly increased blood vessel size, intraluminal echogenicity and a loss of compressibility However, on Doppler ultrasound, 130 (92%) cases were detected possessing significantly increased blood vessel size, intraluminal echogenicity, absence of blood flow and negative augmentation effect. Conclusions: From the result of present study, it is concluded that Doppler may be used as gold standard to diagnose the DVT in the lower extremities. This study concludes also that DVT detection accuracy difference between Doppler and Gray Scale ultrasound is minor i.e. 1:1.08. This minor difference encourages the radiology practitioners of periphery to screen DVT in lower extremities through Gray Scale ultrasound, if Doppler ultrasound is unavailable there.

Sensitivity and specificity of three-point compression ultrasonography test performed by emergency physicians for diagnosis of lower limbsdeep venous thrombosis

 Deep vein thrombosis (DVT) is defined as development of thrombosis within the deep veins of the pelvis or lower limbs. Thrombus formation is a dynamic, multifactorial process that depends on a fine balance of physical and biochemical factors. The causes of thrombosis include three main causes: vessel wall injury, hypercoagulability, and venous stasis which is known as Virchow’s triad. Early detection of deep venous thrombosis is very important not only to initiate anticoagulant therapy, but also very important to prevent further complications and to reduce morbidity and mortality. Diagnosis of DVT depends on clinical examination, laboratory and radiological investigations. Development of DVT is affected by many factors either genetic or acquired risk factors like age, Trauma, Cancer, Surgery, Pregnancy, Obesity, Immobility, hospitalization, hormonal therapy, inherited and acquired hypercoagulable states, anaesthesia, myocardial infarction, history of DVT, varicose veins, infections, inflammatory bowel disease, dehydration, and renal impairment are common risk factors.  Compression ultrasonography is the first-line imaging tool for diagnosis of DVT because it is safe, easily accessible, cost-effective, and reliable.It is accurate to determine the size, chronicity, and degree of occlusion ofthrombus which is very helpful for making the decision of starting medical management or interventional techniques.

EFFECTIVENESS OF DEEP VENOUS THROMBOSIS PREVENTION IN TOTAL HIP ARTHROPLASTY.

ABSTRACTObjective: To determine the efficacy of Deep Venous Thrombosis (DVT) prophylaxis protocol in patients undergoing total hip arthroplasty (THA), and to verify differences in the rates of this complication when comparing primary replacement surgeries with revision surgeries.Methods: We conducted a retrospective study of patients operated between 2012 and 2018, with inclusion and non-inclusion criteria determined by the researchers. A protocol was created to compile data including 92 patients, amounting to 110 operated hips, divided by gender, age, laterality, among other criteria. For THA cases, low molecular weight heparin chemoprophylaxis was used, associated with the use of pneumatic and elastic compression, concomitant to deambulation as soon as possible. The detection of DVT was determined by clinical evaluation and imaging exams such as: simple radiographs, ultrasound, arterial and venous color doppler, and laboratory tests.Results: The use of the protocol was very effective in our study. Only one (1.09%) case of deep venous thrombosis was found.Conclusion: The use of thromboprophylaxis for DVT is indispensable, as was clearly demonstrated by these cases. We observed only one (1.09%) case of DVT in our series. Level of Evidence III, Retrospective Study.

Impact of CT venography added to CT pulmonary angiography for the detection of deep venous thrombosis and relevant incidental CT findings

ObjectivesTo assess the additional diagnostic value of CT venography (CTV) simultaneously performed with CT pulmonary angiography (CTPA) in the context of thromboembolic disease for the detection of deep venous thrombosis (DVT) and other relevant incidental CT findings. Materials and MethodsRetrospectively and consecutively, we included all patients referred to our emergency department within the last 24 months for suspected pulmonary embolism (PE) who underwent CTPA combined with CTV. Two radiologists blinded to clinical information and results independently analysed CTV images in the context of DVT of the lower extremities and other, unsuspected abdominal/pelvic findings. These latter were classified as relevant with therapeutic consequences or irrelevant. One radiologist reviewed patient clinical records. Inter-observer agreement for DVT detection was calculated. ResultsOf 696 patients, 119 had PE (17.1%) and 54 had DVT (7.8%), 16 (2.3%) of them without concomitant PE. Inter-observer agreement between the two readers was substantial (kappa = 0.78). CTV examinations led to diagnosis of relevant incidental abdominal/pelvic findings in 40 (5.7%) patients, including 11 with new malignant tumours, and 8 with progressive metastatic disease. The evaluated clinical and biological risk factors were not significantly associated with the presence of relevant incidental findings. CTV changed therapeutic management in 29 patients (4.3%): 15 had DVTs without PE, and 14 had abdominal/pelvic findings with therapeutic consequences. ConclusionCTV simultaneously performed with CTPA offers limited incremental value for detecting DVT. It may reveal other relevant findings leading to therapeutic changes, but the low rate does not justify screening patients with suspected PE.

LARGE SADDLE PULMONARY EMBOLUS IN AN ASYMPTOMATIC PATIENT

SESSION TITLE: Medical Student/Resident Pulmonary Vascular Disease Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Pulmonary embolism (PE) represents a mechanical obstruction of one or more branches of the pulmonary vasculature, usually due to a blood clot. Saddle PE lodges at the bifurcation of the main pulmonary artery, often extending into the right and left main pulmonary arteries. Approximately 3 to 6 percent of patients with PE present with a saddle embolus. We report an atypical case of asymptomatic large saddle PE with normal right heart function. CASE PRESENTATION: A 47-year-old male with history of diabetes, OSA, hypertension, obesity and family history of Factor V Leiden mutation presented with 1-day history of progressively worsening left leg pain and swelling. He denied any fevers, chills, SOB, cough or palpitations, recent surgery, or long car rides. On physical examination, the patient was comfortable, alert and oriented, afebrile, respiratory rate 21/minute, saturating 97% on room air. Laboratory workup was insignificant. EKG showed sinus tachycardia. Venous scan of left lower extremity revealed subacute deep venous thrombosis (DVT) involving the left femoral and popliteal veins. CT pulmonary angiography (CTPA) revealed extensive bilateral pulmonary emboli with large saddle. 2D ECHO revealed normal left ventricle (LV) systolic function with ejection fraction >55% and normal right ventricle (RV) size and function. Patient was started on heparin drip and switched to Eliquis. He was discharged home in a stable condition. DISCUSSION: Saddle PE is a radiologic definition and refers to thrombus that straddles the bifurcation of the pulmonary artery trunk. Saddle PE is found in 2.6% to 5.4% of patients with PE.1,2 Patients with saddle PE presented more frequently with concurrent DVT on hospital admission (75%).3 The presenting symptoms are dyspnea (72%), syncope (43%). Our patient presented with progressive left leg swelling and pain with DVT and no respiratory symptoms. Alkinj et al in 20172 had reported that 18% of patients with saddle PE had normal RV systolic function. One third patients had hemodynamic instability fulfilling the definition of massive PE unlike in our patient. Our patient was hemodynamically stable and had normal RV function, the risk of bleeding outweighed the benefits of fibrinolytic therapy, therefore this patient was managed with conventional treatment. CONCLUSIONS: Despite looking sinister in appearance on imaging studies, patients with saddle pulmonary embolus may be nearly asymptomatic, hemodynamically stable and can be successfully managed with conventional treatment. Reference #1: Ryu JH, Pellikka PA, Froehling DA, Peters SG, Aughenbaugh GL.Saddle pulmonary embolism diagnosed by CT angiography: frequency,clinical features and outcome. Respir Med. 2007;101(7):1537-1542. Reference #2: Alkinj B, Pannu BS, Apala DR, Kotecha A, Kashyap R, Iyer VN. Saddle vs Nonsaddle Pulmonary Embolism: Clinical Presentation, Hemodynamics, Management, and Outcomes. Mayo Clin Proc. 2017;92(10):1511-1518. Reference #3: Girard P, Musset D, Parent F, Maitre S, Phlippoteau C, Simonneau G. High prevalence of detectable deep venous thrombosis in patients with acute pulmonary embolism. Chest 1999;116:903-8. DISCLOSURES: No relevant relationships by Salil Avasthi, source=Web Response No relevant relationships by DEEPTI AVASTHI, source=Web Response No relevant relationships by Rathnavali Katragadda, source=Web Response No relevant relationships by Shanti Pittampalli, source=Web Response

Evaluation of stability of deep venous thrombosis of the lower extremities using Doppler ultrasound

ObjectiveThis study aimed to assess using Doppler ultrasound for analyzing stability of deep venous thrombosis (DVT) of the lower extremities.MethodsPatients with DVT of the lower extremities who were treated from August 2017 to December 2019 were selected. The patients were divided into stable and unstable groups according to whether thrombus was collected in a filter. Related ultrasound and blood test results were analyzed and compared.ResultsA total of 126 patients with DVT of the lower extremities were included, of whom 74 were in the stable group and 52 were in the unstable group. There were significant differences in the prothrombin time (PT), and lipoprotein alpha, D-dimer, and triglyceride levels between the groups. D-dimer levels >2800 ug/L, smoking, history of venous thrombosis, PT >13.15 s, and body mass index >24.45 kg/m2 were independent risk factors for stability of DVT of the lower extremities. The area under the curve with combined detection of DVT was significantly higher than that for body mass index, PT, and D-dimer alone.ConclusionDoppler ultrasound may be reliable for analyzing the stability of DVT of the lower extremities. Related strategies targeting risk factors are required for reducing DVT of the lower extremities.

Early Detection of Deep Venous Thrombosis in Trauma Patients.

BackgroundThis study was performed to determine whether trauma patients are at an increased risk of developing deep venous thrombosis (DVT) within the first 48 hours of hospitalization.Materials and methodsA retrospective review was performed using a prospectively maintained database of patients admitted to a trauma center during a five-year time period. Patients hospitalized for greater than 48 hours who received a screening venous duplex for DVT were included in the study.ResultsThere were 1067 venous duplex scans obtained, 689 (64.5%) within the first 48 hours of admission (early DVT group), 378 (35.4%) after the first 48 hours (late DVT group). Only 142 (13.2%) patients had a positive duplex scan for DVT, 55 (early group), 87 (late group). Comorbid conditions of congestive heart failure (P = 0.02), pelvic fractures (P = 0.04), and a lower initial systolic blood pressure on presentation (p = 0.04) were associated with early DVT. Head trauma (P < 0.01), mechanical ventilation (P < 0.001), and transfusion of blood products (P < 0.001), were predictors of DVT in the late group.ConclusionsTrauma patients are at an increased risk of developing venous thrombosis early in the hospital course due to comorbidities associated with trauma. Whereas, venous thrombosis in trauma patients diagnosed after the first 48 hours of hospitalization appears to be associated with prolonged patient immobility.

Risk of deep venous thrombosis after total knee arthroplasty in patients with haemophilia A

Venous thromboprophylaxis remains controversial in patients with haemophilia undergoing major orthopaedic surgery, due to clotting factor replacement therapy to correct the patient's inherent haemostatic defect during procedure, at least in theory. We have previously reported that deep venous thrombosis (DVT) was not detected on ultrasonography (US) after total knee arthroplasty (TKA) in 36 Japanese patients with haemophilia. To evaluate the prevalence of DVT after TKA among haemophilic A patients using not only US, but also contrast-enhanced CT prospectively. This study enrolled 11 TKAs in 11 Japanese patients with haemophilia A not having any history of inhibitor. A pneumatic compression device was used from the beginning of the operation until the patient could perform standing exercises (day 2). US of the lower extremities was performed before and after surgery (day 2) to detect DVT. Contrast-enhanced CT was performed after surgery (day 7) to detect VTE. D-dimer was measured at pre- and postoperative time. Mean (±standard deviation) age at the time of operation was 50.5±12.3years. DVT was not found on either pre- or postoperative examinations by US, but contrast-enhanced CT was detected DVT in two cases. No patients showed clinical signs for VTE during hospitalization, and no additional treatment for VTE. No episodes of unexpected bleeding were encountered. Contrast-enhanced CT detected DVT in 18% of haemophilia A patients who underwent TKA despite no detection of DVT on US. We must consider how to prevent and treat VTE in patients with haemophilia scheduled to undergo orthopaedic surgery.

Trombosis venosa profunda en extremidades inferiores: revisión de las técnicas de diagnóstico actuales y su simbiosis con el aprendizaje automático para un diagnóstico oportuno

La Trombosis Venosa Profunda (TVP) es una manifestación de una Enfermedad Tromboembólica (ET). Cuando en una TVP los trombos venosos se desprenden y viajan a través del torrente sanguíneo pueden ocasionar una Trombo Embolia Pulmonar (TEP). La existencia de Trombosis Venosa Profunda (TVP) en las extremidades inferiores se ha descrito como uno de los principales factores de riesgo para el desarrollo de la TEP. Se considera que hasta el 90% de los émbolos pulmonares proceden de trombos venosos de las extremidades inferiores. Las técnicas más utilizadas para la detección de TVP son los modelos de probabilidad clínica, el dímero D y las pruebas de imagen no invasivas, como la ecografía para la TVP y la angiotomografía computadorizada (TC) para el embolismo pulmonar. Sin embargo, debido a la inespecificidad de los síntomas de la TVP, el umbral para ordenar una ecografía es bajo, además de ser un proceso complicado que requiere la participación de un médico especialista para su interpretación. En las últimas décadas el aprendizaje automático ha surgido como apoyo en la toma de decisiones para el diagnóstico de diversas enfermedades, algunas de las tecnologías más utilizadas en el campo de la medicina incluyen Support Vector Machine (SVM), Árboles de decisión y las Redes Neuronales Artificiales (RNA). En el presente artículo se hace una revisión de las tecnologías existentes para la detección de la TVP así como de los principales algoritmos de aprendizaje automático comúnmente utilizados en aplicaciones biomédicas; se propone el diseño de un sistema computarizado que utilice técnicas de aprendizaje automático como herramienta de apoyo para la detección oportuna de un posible padecimiento de TVP.

Clinical value of blood D-dimers in lower extremity deep venous thrombosis in patients with severe combined abdominal trauma

Aim. To establish sensitivity and specificity of deep vein thrombosis detection in patients with severe combined abdominal trauma by studying cross-linked fibrin degradation products (D-dimer) using erythrocyte agglutination SimpliRED® technology. Materials and methods . We analyzed the treatment results of 105 patients with severe combined abdominal trauma who underwent surgery inLvivThoraco-AbdominalTraumaCenter (Surgical Department No. 1), Traumatology and Neurosurgery Departments of the Lviv City Emergency Hospital in 2012–2017. Results. The sensitivity and specificity of lower extremity deep venous thrombosis detection in patients with severe combined abdominal trauma was established by studying D-dimers as well as their dynamics. Mandatory inclusion criteria for the study were: negative result of the D-dimer test upon admission, absence of instrumental and clinical signs of lower extremity deep venous thrombosis. The examination was performed prior to the operation or mini-invasive methods of diagnostics (laparoscopy) and on day 3 and 7 after. The high value of the method is explained by its maximum adaptation to the conditions of urgent surgery; it does not require specific inhibitors, does not depend on blood sampling technology or platelet count and can be performed in a few minutes. A positive result, which indicated the active fibrinolysis, was evaluated within 2 min by erythrocyte agglutination in a test cell and the latter absence in a control one. The D-dimer test was positive in 78 (74.3 %) patients in the study group. The peak of positive test results was observed on the 5th day after surgery. In all the injured with lower extremity deep venous thrombosis, a strong positive test result was revealed, which was manifested by erythrocyte agglutination at the 5–20 sec and the presence of D-dimers for a long time (an average of 19.3 ± 7.1 days). In the low-risk group of deep vein thrombosis and embolism by J. Caprini, the positive test was detected in 6 (5.7 %) patients, in the moderate and high-risk groups – in 28 (26.7 %) and 44 (41.9 %), respectively. Conclusions. The method of D-dimers detection in blood by SimpliRED ® technology showed a rather high sensitivity in patients with severe combined abdominal trauma of 82.3 %, but low specificity of 32.3 %. In the absence of prophylaxis, the incidence of deep vein thrombosis in patients with severe combined abdominal trauma was 25.7 %. The method of ultrasonic compression angioscanning of the lower extremity veins verified the proximal vein thrombosis predominance – 74.1 %. The risk of thrombus fragmentation and potential pulmonary thromboembolism was detected in 13.7 % of patients.

Fat-suppressed magnetic resonance volume interpolated examination for deep venous thrombosis compared with duplex sonography.

The aim of the present study was to evaluate magnetic resonance venography (MRV) scanned by breath-hold volume interpolated body examination with spectral fat saturation (VIBE-fs), combined with Dixon fat-suppressed VIBE (VIBE-Dixon) by using a 1.5T MR scanner for detecting deep venous thrombosis (DVT) compared with duplex sonography. A total of 31 patients with DVT were identified using duplex sonography and were enrolled in the present study for MRV examination, from the inferior vena cava to the ankle level after injection of gadopentetate dimeglumine. Venous segment-to-segment comparison was assessed for DVT detection between MRV and duplex sonography. A total of two radiologists separately performed subjective image quality assessment using a 5-point scale. Cohen's κ coefficient, Wilcoxon rank sum test and intraclass correlation coefficient values were used for statistical analysis. Of the 303 evaluated vein segments, duplex sonography identified 119 (39.3%; 119/303) venous segments with thrombus, while MRV detected 170 (56.1%; 170/303) venous segments with thrombus. The diagnostic agreement rate of DVT between duplex sonography and MRV was poor in the deep femoral vein and anterior tibial veins, while it was excellent in the inferior vena cava (IVC), common iliac vein, external iliac vein, femoral vein, popliteal vein, posterior tibial veins and peroneal veins. In addition, poor reliability was detected in the deep femoral vein, anterior tibial veins and peroneal veins, but good to excellent reliability was observed in IVC, common iliac vein, external iliac vein, femoral vein, popliteal vein and posterior tibial veins. Furthermore, image quality scores of each venous segment between the two radiologists indicated no statistical difference. Therefore, MRV scanned using VIBE-fs for the suprainguinal and VIBE-Dixon for the infrainguinal region may be a useful method for detecting DVT compared with duplex sonography. The results of present study proved this MR protocol to be a beneficial alternative imaging modality for the detection of DVT when duplex sonography is inadequate or not able to be performed.

Intra-articular 1g tranexamic acid administration during total knee arthroplasty is safe and effective for the reduction of blood loss and blood transfusion.

The effect of tranexamic acid (TXA) on the incidence of venous thromboembolic events (VTEs) in total knee arthroplasty (TKA) as assessed by contrast-enhanced computed tomography (CT) is unclear. Thus, we investigated the efficacy and safety profiles of TXA administration during TKA. We hypothesised that intra-articular 1g TXA administration would have a sufficient effect on the reduction of blood loss and transfusion rates without increasing VTE risk. We retrospectively analysed 86 patients who underwent primary TKA from January 2014 to September 2017. The study comprised control (n = 45) and TXA (n = 41) groups. All patients underwent navigation-assisted TKA via the medial parapatellar approach. In those who received TXA, 1g of intra-articular TXA was injected via a drain immediately following wound closure. The drain was clamped for 2h and then reopened. Contrast-enhanced CT was performed 5-6days after surgery to detect deep venous thrombosis (DVT) and pulmonary embolism (PE). Blood loss was calculated using the haemoglobin balance method. The mean postoperative volume of blood loss was 900 ± 296mL vs 1216 ± 445mL in the TXA vs control group (p < 0.01). Allogeneic blood transfusion was required for 0 (0%) vs 6 (13.3%) patients in the TXA vs control group (p = 0.013). There were no significant inter-group differences regarding DVT and PE incidence (p > 0.05). No case of symptomatic PE occurred. This study demonstrated that intra-articular 1g TXA administration during TKA is safe and effective for reducing blood loss and blood transfusion without increasing VTE risk.