Calf muscle venous thrombosis: a review of the clinical implications and therapy

Prophylactic Dose of Rivaroxaban Versus Warfarin for the Treatment of Isolated Calf Muscle Vein Thrombosis: A Retrospective Propensity Score-Matched Analysis

BACKGROUND

Prophylactic dose of rivaroxaban is often used in treatment of isolated calf muscle vein thrombosis (ICMVT); nevertheless, its effect is less reported. This study aims to evaluate short-term outcomes in patients with ICMVT who received prophylactic dose of rivaroxaban or warfarin therapy.

METHODS

A retrospective analysis of 472 ICMVT patients who received 2 different treatment regimens was undertaken. Propensity score matching method was used to balance the confounding effect of baseline clinical data. Chi-squared test and logistic regression analysis were used to compare outcomes (venous thromboembolism events, bleeding events, complete clot resolution) according to the type of treatment regimens before and after propensity score matching. Univariate and multivariable analysis were used to investigate risk factors for incomplete clot resolution of ICMVT after propensity score matching.

RESULTS

242 ICMVT patients received prophylactic dose of rivaroxaban (rivaroxaban group, RG), and 230 received warfarin (warfarin group, WG). After propensity score matching, 156 patients were included in each group; Venous thromboembolism (VTE) events occurred in 14 (9.0%) patients in the RG and 10 (6.4%) in the WG (P = 0.395); no major bleeding events occurred in each group, and clinically relevant nonmajor bleeding events occurred in 5 (3.2%) patients in the RG and 10 (6.4%) in the WG (P = 0.186); complete clot resolution at 3 months occurred in 80 (51.3%) patients in the RG and 100 (64.1%) in the WG (P = 0.022). Logistic regression analysis showed that there were no significant differences between RG and WG in VTE events (odds ratio 1.439, 95% confidence interval 0.619-3.347, P = 0.397) and clinically relevant nonmajor bleeding events (odds ratio 0.483, 95% confidence interval 0.161-1.449, P = 0.194); it revealed that complete clot resolution rate at 3 months was different in the 2 groups (odds ratio 0.589, 95% confidence interval 0.375-0.928, P = 0.022). Treatment regimens (prophylactic dose of rivaroxaban), thrombosis (maximum diameter >7 mm), and risk factors for VTE (nonsurgery risk factors, mainly referring to active malignancy) were risk factors for incomplete clot resolution of ICMVT (P < 0.05).

CONCLUSIONS

In this retrospective study with a short-term follow-up, ICMVT patients who received prophylactic dose of rivaroxaban had no significant differences in VTE and bleeding events compared to those who received warfarin therapy (the overall INR >2.0 for >50% of the time); but it was not conducive to complete clot resolution.

Predictive factors of postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to intensive care unit: a retrospective cohort study

BACKGROUND

The epidemiology and risk factors for postoperative complications related to free flap reconstruction in head and neck cancer patients admitted to the Intensive Care Unit (ICU) are unknown.

METHODS

We performed a retrospective cohort study of patients with free flap reconstruction of head and neck cancer between September 2015 and April 2023 admitted to the ICU of Beijing Tongren Hospital. The univariate and multivariate analyses were used to explore the risk factors for postoperative complications related to free flap reconstruction admitted to ICU, including flap necrosis, bleeding, fistula, and infection.

RESULTS

A total of 239 patients were included in this study, and 38 (15.9%) patients had postoperative complications related to free flap reconstruction. The median length of ICU stay was 1 day (interquartile range, 1-2 days). Multivariate analysis found that low BMI (P < 0.001), high postoperative CRP (P = 0.005), low hemoglobin (P = 0.012), and inadequate fluid intake (P < 0.05) were independent risk factors for complications.

CONCLUSIONS

Postoperative complications related to free flap reconstruction were common in this ICU population. Careful fluid management and monitoring of CRP and hemoglobin levels may reduce complications.

Recurrence in isolated distal DVT after anticoagulation: a systematic review and meta-analysis of axial and muscular venous thrombosis

OBJECTIVE

To identify recurrent venous thromboembolism (VTE) after discontinuation of anticoagulation in patients with isolated distal deep vein thrombosis based on its anatomic localization (axial or muscular veins).

METHODS

Data were sourced from PubMed, Embase, Cochrane Library, Web of Science, and ClinicalTrials.gov databases in the time period up to October 2023. The study followed PRISMA guidelines using a registered protocol (CRD42023443029). Studies reporting recurrent VTE in patients with axial or muscular DVT were included in the analysis.

RESULTS

Five studies with a total of 1,403 participants were evaluated. The results showed a pooled odds ratio of 1.12 (95% confidence interval 0.77-1.63) between axial and muscular DVT. Heterogeneity was low (I2 = 0%, p = 0.91) and there was no significant difference in the rate of recurrent VTE between axial and muscular DVT in each subgroup.

CONCLUSIONS

Muscular and axial DVT showed comparable recurrent VTE rates after anticoagulation. However, uncertainties regarding the possibility of recurrence affecting the popliteal vein or resulting in pulmonary embolism following muscular DVT anticoagulation persisted. Randomized trials in patients with isolated distal DVT are still needed to clarify its prognosis for different anatomical thrombus locations.

Independent association between IVC filter placement and VTE risk in patients with upper gastrointestinal bleeding and isolated distal DVT: A retrospective cohort study

BACKGROUND

The placement of inferior vena cava (IVC) filters often emerges as an alternative preventative measure against pulmonary embolism in patients with upper gastrointestinal (GI) bleeding and isolated distal deep vein thrombosis (DVT). We aimed to investigate the association of IVC filter placement and the incidence of venous thromboembolism (VTE) recurrence in this patient population.

METHODS

We performed a retrospective cohort study including 450 patients with upper GI bleeding and isolated distal DVT. Propensity score matching using logistic regression was conducted to mitigate potential selection bias. Logistic regression models and additional sensitivity analyses were conducted to estimate the association between IVC filter implantation and VTE recurrence. Interaction and stratified analyses were also performed according to the background covariates.

RESULTS

Patients who underwent IVC filter placement were significantly younger than patients in the surveillance group (55.8 ± 9.0 vs 58.4 ± 11.2 years, p = 0.034). Patients in the IVC filter group demonstrated a higher distal thrombus burden. The VTE recurrence composite was significantly higher in patients who underwent IVC filter placement (44.1% [45/102] vs 25% [87/348], p < 0.001). Unmatched crude logistic regression analysis identified a significant association between IVC filter placement and VTE recurrence composite (OR = 2.37; 95% CI, 1.50-3.75). Sensitivity analyses yielded congruent outcomes.

CONCLUSION

This study revealed an increased risk of VTE recurrence among patients receiving IVC filter placement, suggesting that IVC filter placement may not be suitable as a primary treatment for patients with upper GI bleeding and isolated distal DVT.

Management of Deep Vein Thrombosis: An Update Based on the Revised AWMF S2k Guideline

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are the most common manifestations of venous thromboembolism (VTE). Most DVTs affect the lower-extremity veins. Since the symptoms of DVT are non-specific, a prompt and standardised diagnostic work-up is essential to minimise the risk of PE in the acute phase and to prevent thrombosis progression, post-thrombotic syndrome and VTE recurrence in the long-term. Only recently, the AWMF S2k guidelines on Diagnostics and Therapy of Venous Thrombosis and Pulmonary Embolism have been revised. In the present article, we summarize current evidence and guideline recommendations focusing on lower-extremity DVT (LEDVT). Depending on whether the diagnostic work-up is performed by a specialist in vascular medicine or by a primary care physician, different diagnostic algorithms are presented that combine clinical probability, D-dimer testing and diagnostic imaging. The diagnosis of ipsilateral recurrent DVT poses a particular challenge and is presented in a separate algorithm. Anticoagulant therapy is an essential part of therapy, with current guidelines clearly favouring regimens based on direct oral anticoagulants over the traditional sequential therapy of parenteral anticoagulants and vitamin K antagonists. For most DVTs, a duration of therapeutic-dose anticoagulation of at least 3 to 6 months is considered sufficient, and this raises the question of the risk of VTE recurrence after discontinuation of anticoagulation and the need for secondary prophylaxis in the long-term. Depending on the circumstances and trigger factors that have contributed to the occurrence of DVT, management strategies are presented that allow decision-making taking into account the individual bleeding risk and patient's preferences.

Comparison of clinical outcomes among patients with isolated axial vs muscular calf vein thrombosis: A systematic review and meta-analysis

OBJECTIVE

Thrombi in the axial calf veins have quite different anatomical and physiological characteristics from that in the muscular calf veins, but their treatment was usually addressed in the same manner. We performed a meta-analysis of randomized and cohort studies to compare clinical outcomes among patients with isolated axial vs muscular calf deep vein thrombosis (DVT).

METHODS

Recurrent venous thromboembolism (VTE) was selected as the primary outcome. Resolution, proximal propagation of calf DVT, pulmonary embolism (PE), major bleeds, and clinically relevant non-major bleeds were separately analyzed as secondary outcomes. Data were pooled and compared with risk ratio (RR) and 95% confidence interval (CI).

RESULTS

Thirteen studies, consisting of 4889 patients, met the inclusion criteria and were included for analysis. A greater rate of recurrent VTE (FE model: RR, 1.23; 95% CI, 1.00-1.53; I2 = 29%), resolution (FE model: RR, 1.32; 95% CI, 1.01-1.72; I2 = 31%), proximal propagation (FE model: RR, 1.63; 95% CI, 1.10-2.41; I2 = 40%), and PE (FE model: RR, 2.79; 95% CI, 1.31-5.95; I2 = 0%) in the axial group compared with the muscular group. There was no difference in the pooled estimates for major bleeds (FE model: RR, 1.09; 95% CI, 0.61-1.95; I2 = 0%), and clinically relevant non-major bleeds (FE model: RR, 1.80; 95% CI, 0.93-3.48) in the axial and muscular arms.

CONCLUSIONS

Patients with calf DVT limited to muscular veins might have a lower rate of recurrent VTE, resolution, proximal propagation, and PE vs those with axial calf vein involvement and exhibited similar safety outcomes.

Follow-up study of isolated calf muscular vein thrombosis for anticoagulant therapy after primary hip and knee arthroplasty

BACKGROUND

Although isolated calf muscular vein thrombosis (ICMVT) is commonly seen after hip and knee arthroplasty, no treatment guidelines for ICMVT after joint replacement are available. The purpose of this study was to evaluate the outcomes of patients with ICMVT for anticoagulant therapy at different time points after primary hip and knee arthroplasty.

METHODS

Patients with ICMVT after primary hip and knee arthroplasty were included in the study. Diagnosis was established with Doppler ultrasound. Patients were followed up clinically and with Doppler ultrasound at 1, 2, and 3 months. The outcomes were efficacy (complete resolution) and acceptability (hemorrhagic events). Anticoagulant therapy at curative dosage was prescribed for 1 month and was extended for 2 additional months in case of incomplete resolution at 1 month or if propagation was present. The chi-square test was used to compare the outcomes at different time points.

RESULTS

302 patients were taken hip and knee arthroplasty from January 2021 to May 2022, in which 51 patients presented with 51 ICMVTs postoperatively. The incidence of ICMVT was about 16.89%. Resolution of ICMVT was considered complete at 1, 2, and 3 months at 36.73%, 61.22%, and 91.84%, respectively, with significant differences among the time points (P < 0.05). All patients with ICMVT receiving anticoagulant therapy remained free of propagations and hemorrhagic events within 3 months.

CONCLUSION

Our findings provide new insights into the anticoagulant therapy for ICMVT after primary hip and knee arthroplasty, taking oral Rivaroxaban for 3 months is effective and safe, which contributes to provide the reference for clinical practice.

Risk factors for lower extremity deep vein thrombosis in acute stroke patients following endovascular thrombectomy: a retrospective cohort study

Background

Deep vein thrombosis (DVT) in lower extremities as a common complication of acute ischemic stroke (AIS) has long been studied. However, as the therapeutic options for AIS continue to advance, the pathogenic mechanisms behind DVT may change. Endovascular thrombectomy (EVT) has replaced intravenous thrombolysis and become the preferred treatment for AIS patients with large vessel occlusions. Therefore, it is important to update our understanding of DVT and its management. This study aimed to determine the prevalence and risk factors of DVT in AIS patients following EVT.

Methods

In this retrospective study, 245 AIS patients who had received EVT were recruited between January 2020 and December 2021. Within 10 days (median 4 days) of thrombectomy, DVT was diagnosed by ultrasonography. Demographic characteristics, clinical findings, and therapeutic procedures were compared between patients with and without DVT using univariate analysis. Cutoff points were defined for EVT time and plasma D-dimer concentration. Multivariable logistic regression was then used to determine the independent risk factors for DVT and evaluate their predictive power.

Results

The prevalence of DVT in AIS patients after EVT was 27.3%. Multifactorial logistic regression analysis showed that age (OR 1.036, 95% CI 1.001-1.073; P = 0.045), female sex (OR 3.015, 95% CI 1.446-6.289; P = 0.003), lower limb muscle strength less than grade three (OR 7.015, 95% CI 1.887-26.080; P = 0.004), longer EVT time (OR 1.012, 95% CI 1.004-1.020; P = 0.003), and higher D-dimer levels (OR 1.350, 95% CI 1.150-1.585; P < 0.001) were independently associated with higher DVT risk in AIS patients following EVT. The cutoff points for operative time of EVT and plasma D-dimer were 65.5 min and 1.62 mg/L, respectively, above which the risk for DVT was dramatically increased with OR > 4 in AIS patients.

Conclusion

AIS patients are at increased risk of developing DVT following EVT particularly if they have undergone prolonged thrombectomy procedures and exhibit high plasma levels of D-dimers. However, the results of our study need to be validated by a multicenter prospective study with a larger population of stroke patients.

Risk factors and prediction model of nomogram for preoperative calf muscle vein thrombosis in geriatric hip fracture patients

Introduction

Calf muscular vein thrombosis (CMVT) is a common complication in geriatric hip fracture patients. Despite its high incidence, prior research on the topic is limited. The occurrence of CMVT in patients will prolong the preoperative waiting time and even lead to serious thromboembolic events, which can be detrimental to the patient's prognosis. Therefore, this study aimed to identify the risk factors for preoperative CMVT in geriatric hip fracture patients and construct a nomogram model to predict the risk of preoperative CMVT in patients.

Materials and methods

Geriatric hip fracture patients who underwent surgery between January 2019 and January 2022 were included. The patients were categorized into two groups depending on whether they had preoperative CMVT, confirmed through Color Doppler ultrasound or venography examination. Univariate and multivariate logistic regression analyses were used to analyze demographic characteristics, medical history, comorbidities, and laboratory tests. A nomogram was constructed to predict preoperative CMVT in geriatric hip fracture patients based on the results of the multivariate logistic regression.

Results

Three hundred and eighty-eight geriatric hip fracture patients, including one hundred and thirty-four patients with CMVT and two hundred and fifty-four patients without CMVT, were ultimately included in our study. After multivariable logistic regression analysis, the time from injury to admission, smoking history, serum albumin levels, and D-dimer levels was identified as independent risk factors and was entered into a nomogram model. The nomogram showed robust discrimination, with an area under the receiver operating characteristic curve of 0.805. The calibration curve showed strong agreement between the CMVT probabilities predicted by the nomogram and the actual probabilities. The decision curve analysis illustrates the excellent clinical utility of the model.

Conclusion

We have constructed a new nomogram prediction model that can effectively predict the risk of preoperative CMVT in geriatric hip fracture patients based on their medical history and blood test results. This model can help clinicians make individualized predictions of CMVT that are tailored to each patient's unique circumstances.

Incidence and risk factors of isolated calf muscular venous thrombosis after tibial plateau fractures surgery

BACKGROUND

The risks associated with deep vein thrombosis (DVT) have gained significant recognition over time. A prevalent form of distal DVT is isolated calf muscular venous thrombosis (ICMVT). Despite its common clinical occurrence, data on ICMVT subsequent to tibial plateau fracture (TPF) surgery are scarce. This study aimed to examine the epidemiological characteristics and associated risk factors (RFs) of ICMVT following TPF surgery.

METHODS

For this retrospective analysis, we included patients from our hospital, who underwent TPF surgery between March 2017 and March 2021. Patients' electronic medical records were reviewed, including admission details, fracture classification, surgical procedures, and laboratory biomarkers. The HSS (The American Hospital for Special Surgery) and Rasmussen scores were employed to evaluate the clinical effect. A Color Duplex Flow Imager (CDFI) was regularly used to detect pre- and postoperative venous thrombosis in the lower limbs. Finally, uni- and multivariate logistic regression analyses were used to identify independent RFs associated with ICMVT.

RESULTS

Overall, 481 participants were recruited for analysis. Postoperative ICMVT occurred in 47 patients. All ICMVTs occurred on the affected side. Four of the 47 ICMVT patients exhibited sudden postoperative swelling in the affected limb. The HSS and Rasmussen scores in the non-ICMVT cohort (87.6 ± 8.2, 16.0 ± 1.7) were markedly different from the ICMVT cohort (84.8 ± 8.2, 15.5 ± 1.6) (p = 0.014, p = 0.031). This study finally identified five postoperative ICMVT-related RFs, which were age (> 55 years old) (OR 3.06; 95% CI 1.47-6.37; p = 0.003), gender (female) (OR 2.67; 95% CI 1.37-5.22; p = 0.004), surgical duration (> 114 min) (OR 3.14; 95% CI 1.44-6.85; p = 0.004), elevated white blood cell content (OR 2.85; 95% CI 1.47-5.51; p = 0.002), and hyponatremia (OR 2.31; 95% CI 1.04-5.12; p = 0.040).

CONCLUSION

The epidemiological findings of this study may help predict ICMVT risk after surgery thus facilitating the development of individualized clinical assessments and targeted prevention programs.

Classification of deep vein thrombosis stages using convolutional neural network of electromyogram with vibrotactile stimulation toward developing an early diagnostic tool: A preliminary study on a pig model

Deep vein thrombosis (DVT) can lead to life-threatening disorders; however, it can only be recognized after its symptom appear. This study proposed a novel method that can detect the early stage of DVT using electromyography (EMG) signals with vibration stimuli using the convolutional neural networks (CNN) algorithm. The feasibility of the method was tested with eight legs before and after the surgical induction of DVT at nine-time points. Furthermore, perfusion pressure (PP), intracompartmental pressure (IP), and shear elastic modulus (SEM) of the tibialis anterior were also collected. In the proposed method, principal component analysis (PCA) and CNN were used to analyze the EMG data and classify it before and after the DVT stages. The cross-validation was performed in two strategies. One is for each leg and the other is the leave-one-leg-out (LOLO), test without any predicted information, for considering the practical diagnostic tool. The results showed that PCA-CNN can classify before and after DVT stages with an average accuracy of 100% (each leg) and 68.4±20.5% (LOLO). Moreover, all-time points (before induction of DVT and eight-time points after DVT) were classified with an average accuracy of 72.0±11.9% which is substantially higher accuracy than the chance levels (11% for 9-class classification). Based on the experimental results in the pig model, the proposed CNN-based method can classify the before- and after-DVT stages with high accuracy. The experimental results can provide a basis for further developing an early diagnostic tool for DVT using only EMG signals with vibration stimuli.

Increased incidence of venous thromboembolism associated with inferior vena cava filter placement in patients diagnosed with isolated calf deep vein thrombosis after intracranial hemorrhage or intracranial operation

In this study, we sought to investigate the effectiveness of inferior vena cava (IVC) filter placement in reducing the incidence of venous thromboembolism (VTE) in patients diagnosed with isolated calf deep vein thrombosis (DVT) after an intracranial hemorrhage or intracranial operation. A retrospective chart review (January 2000-December 2019) was performed to identify patients diagnosed with calf DVT after intracranial hemorrhage or intracranial operation. A total of 100 patients met the study criteria and were divided into groups based on treatment: IVC filter placement (n = 22), prophylactic anticoagulation (n = 42), or imaging surveillance (n = 36). Treatment-related complications were identified, and differences between groups in the primary endpoint (VTE occurrence after DVT diagnosis) were assessed using logistic regression. VTE occurred in 15 patients after calf DVT diagnosis. The rate of VTE was higher in the IVC filter group (9/22; 41%) than in the anticoagulation (2/42; 5%; p = 0.002) and surveillance (4/36; 11%; p = 0.013) groups. These treatment effects remained significant after adjustments were made for baseline characteristics (IVC filter vs anticoagulation, p = 0.009; IVC filter vs surveillance, p = 0.019). There was a single occurrence of pulmonary embolism in the surveillance group (3%). A single case of IVC filter thrombus was identified; no anticoagulation-related complications were reported. The findings of this study do not support IVC filter placement as a primary and solitary treatment for isolated calf DVT occurring after intracranial hemorrhage or intracranial operation.

The Risk Factors for New-Onset Calf Muscle Venous Thrombosis after Hip Fracture Surgery

BACKGROUND

Calf muscle venous thrombosis (CMVT) is among the most important medical complications after hip surgery. CMVT has been known for many years, but many opinions about the incidence and risk factors of CMVT are still controversial. The objective of this retrospective study was to investigate the incidence and associated risk factors of postoperative CMVT in patients with hip fractures.

METHODS

Patients with hip fractures from January 2020 to April 2022 (n = 320) at Shenzhen Second People's Hospital were recruited in this study. The personal characteristics and clinical data of CMVT and no-CMVT patients were compared and analyzed. Binary logistic regression analyses were performed to identify potential risk factors of CMVT in patients with hip fractures. Finally we performed a receiver operating characteristic (ROC) curve analysis to compare the diagnostic values of different variables.

RESULTS

The overall incidence of new-onset CMVT in patients with hip fractures was 18.75% (60 of 320). Among the 60 CMVT patients, 70% (42 of 60) were diagnosed with femoral neck fractures, 28.3% (17 of 60) with intertrochanteric fractures, and 1.7% (1 of 60) with subtrochanteric fractures. No pulmonary embolism (PE) occurred. High preoperative D-dimer (OR = 1.002, 95%CI 0.97-1.03), sex (OR = 1.22, 95%CI 0.51-2.96), the caprini score (OR = 2.32, 95%CI 1.05-5.16) and the waterlow score (OR = 1.077, 95%CI 0.35-3.36) significantly increased the risk of developing postoperative new-onset CMVT.

CONCLUSIONS

CMVT has become a common clinical disease, and its harm should not be underestimated. Our study found that D-dimer, sex, the caprini score and the waterlow score were independent risk factors for postoperative CMVT. According to our clinical work, we should pay attention to identifying the risk factors of CMVT formation and targeted intervention measures to prevent new-onset CMVT.

Developing and optimizing a machine learning predictive model for post-thrombotic syndrome in a longitudinal cohort of patients with proximal deep venous thrombosis

BACKGROUND

Post-thrombotic syndrome (PTS) is the most common chronic complication of deep venous thrombosis (DVT). Risk measurement and stratification of PTS are crucial for patients with DVT. This study aimed to develop predictive models of PTS using machine learning for patients with proximal DVT.

METHODS

Herein, hospital inpatients from a DVT registry electronic health record database were randomly divided into a derivation and a validation set, and four predictive models were constructed using logistic regression, simple decision tree, eXtreme Gradient Boosting (XGBoost), and random forest (RF) algorithms. The presence of PTS was defined according to the Villalta scale. The areas under the receiver operating characteristic curves, decision-curve analysis, and calibration curves were applied to evaluate the performance of these models. The Shapley Additive exPlanations analysis was performed to explain the predictive models.

RESULTS

Among the 300 patients, 126 developed a PTS at 6 months after DVT. The RF model exhibited the best performance among the four models, with an area under the receiver operating characteristic curves of 0.891. The RF model demonstrated that Villalta score at admission, age, body mass index, and pain on calf compression were significant predictors for PTS, with accurate prediction at the individual level. The Shapley Additive exPlanations analysis suggested a nonlinear correlation between age and PTS, with two peak ages of onset at 50 and 70 years.

CONCLUSIONS

The current predictive model identified significant predictors and accurately predicted PTS for patients with proximal DVT. Moreover, the model demonstrated a nonlinear correlation between age and PTS, which might be valuable in risk measurement and stratification of PTS in patients with proximal DVT.

A risk prediction model for evaluating thrombosis extension of muscle calf venous thrombosis after craniotomy

Objective

To explore the risk factors of muscle calf venous thrombosis (MCVT) after craniotomy and construct a risk prediction model, so as to provide tool for evaluating the prognosis of MCVT after craniotomy.

Methods

Retrospective analysis was performed on the data of patients undergoing craniotomy complicated with MCVT from January 1, 2018 to December 31, 2020. A prediction model was established by Logistic regression, and the predictive efficacy of the model was tested by ROC curve. The accuracy of the risk model was evaluated by Hosmer-Lemeshow (H-L) test, and the model was verified internally by cross validation.

Results

Among the 446 patients who underwent craniotomy complicated with MCVT, 112 cases (25.11%) had thrombosis extension. D-dimer, Capirini scores, length of hospital stay, malignant tumor, fracture, use of dehydrating agents and hemostatic agents were independently related to thrombosis extension after craniotomy. The area under ROC curve (AUROC) of the prediction model was 0.918 (0.888, 0.942), and the sensitivity and specificity of the maximum Youden index were 85.3% and 78.2%, respectively. H-L test showed that the prediction model was accurate (χ² = 12.426, P = 0.133). The internal verification results of the prediction model showed that the AUROC value of the prediction model is 0.892.

Conclusion

The prediction model has a good prediction efficacy on the prognosis of post-craniotomy patients complicated with MCVT, and can be used as a tool to evaluate the risk of thrombosis extension.

A Nomogram for Individualized Prediction of Calf Muscular Vein Thrombosis in Stroke Patients During Rehabilitation: A Retrospective Study

Objectives: To develop a nomogram for predicting calf muscle veins thrombosis (CMVT) in stroke patients during rehabilitation. Methods: We enrolled 360 stroke patients from the Rehabilitation Medicine Center from December 2015 to February 2019. Of the participants, 123 were included in the CMVT group and 237 in the no CMVT group. The least absolute shrinkage and selection operator (LASSO) regression model was applied to optimize feature selection for the model. Multivariable logistic regression analysis was applied to construct a predictive model. Performance and clinical utility of the nomogram were generated using the Harrell's concordance index, calibration curve, and decision curve analysis (DCA). Results: Age, Brunnstrom stage (lower extremity), D-dimer, and antiplatelet therapy were associated with the occurrence of CMVT. The prediction nomogram showed satisfactory performance with a concordance index of 0.718 (95% CI: 0.663-0.773) in internal verification. The Hosmer-Lemeshow test, P = .217, suggested that the model was of goodness-of-fit. In addition, the DCA demonstrated that the CMVT nomogram had a good clinical net benefit. Conclusions: We developed a nomogram that could help clinicians identify high-risk groups of CMVT in stroke patients during rehabilitation for early intervention.

The Incidence and Location of Deep Vein Thrombosis in Lower Extremity Fracture Patients Receiving Sequential Chemical Prophylaxis

To investigate the incidence and location of deep vein thrombosis (DVT) in patients with lower extremity fractures receiving pharmacological thromboprophylaxis with LMWH followed by rivaroxaban. All patients aged ≥18 years with lower extremity fractures were included in the study. Duplex ultrasonography (DUS) was performed in the lower extremities before and after surgery for DVT evaluation. According to the location, the DVT was divided into proximal, distal, and mixed thromboses. According to fracture location, patients were classified as having fractures proximal, around, and distal to the knee. All patients received sequential chemical prophylaxis. A total of 404 patients with a mean age of 44.2 ± 13.8 years were included. The incidence of DVT postoperatively was higher than that preoperatively and at 1 month postoperatively. Patients with fractures proximal and around the knee had higher DVT incidences detected on DUS postoperatively and at 1 month postoperatively. Most DVTs were located in the distal vein. DVT incidence and severity were the highest immediately after surgery. DVT incidence in fractures around and proximal to the knee increased after surgery and at 1 month postoperatively. Although with chemical thromboprophylaxis, distal DVT was the most variable during the early stage.

The anatomic distribution and pulmonary embolism complications of hospital-acquired lower extremity deep venous thrombosis

OBJECTIVE

The anatomic distribution of lower extremity deep venous thrombosis (LEDVT) plays an important role in its prevention and treatment. This study aimed to evaluate the anatomic distribution of hospital-acquired LEDVT (HA-LEDVT) and its probable role in the occurrence of pulmonary embolism (PE).

METHODS

We retrospectively analyzed the demographic data, ultrasound results, and PE-related findings of inpatients with HA-LEDVT in 28 clinical departments at Peking University People's Hospital between January 1, 2007, and December 31, 2018.

RESULTS

This study included 1431 HA-LEDVT events: 35.8%, 31%, and 33.3% were left, right, and bilateral LEDVT. Isolated distal, proximal, and blended DVT were detected in 83.4%, 7.3%, and 9.3% of the patients, respectively. The distribution of HA-LEDVT in the left and right lower extremities were not significantly different except in patients aged ≥40 years (left: 2.07 vs right: 1.88 per 1000 extremities, P = .04). For anatomic types of HA-LEDVT, isolated distal HA-LEDVT was 5.02 times more prevalent than proximal HA-LEDVT (1.24 vs 0.26 per 1000 extremities, P ＜ .01). The involvement rates of specific deep veins by HA-LEDVT were highest in the muscular calf vein (87.5%) followed by the popliteal vein (10.1%), superficial femoral vein (9.3%), and common femoral vein (9.2%). HA-LEDVT involving multiple vein segments simultaneously occurred in 338 extremities. HA-LEDVT involving the muscular calf vein and at least one of three connected axial veins of the muscular calf vein occurred most frequently. Eighty-eight patients with HA-LEDVT (6.15%) had PE. The frequency of PE among patients with proximal and distal DVT (7.89% vs 6.23% P = .275) was not significantly different. The incidence of PE was highest in patients with bilateral proximal DVT (15.4%) and lowest in patients with a single right distal DVT (4.5%). PE occurred in 6% of muscular calf vein HA-LEDVT. In isolated muscular calf vein DVT cases, PE were more likely to occur in cases with a ＞6.05-mm-diameter thrombus than in those with a ＜6.05-mm-diameter thrombus (10.3% vs 4.2%, P ＜ .0001).

CONCLUSIONS

HA-LEDVT is characterized by a significantly high percentage of DVT in the muscular calf vein. Muscular calf vein thrombosis may be the primary origin of lower extremity deep vein thrombosis. The diameter of the thrombus in the muscular calf vein may be associated with the occurrence of PE. More prospective studies are needed to more fully determine the natural history of HA-LEDVT and develop prevention and treatment guidelines for HA-LEDVT.

Perioperative Deep Vein Thrombosis in Patients With Lower Extremity Fractures: An Observational Study

This study aimed to investigate deep vein thrombosis (DVT) in patients with lower extremity fractures who received anticoagulation treatment in the perioperative stage. We collected the patients’ clinical data and diagnosed DVT using Doppler ultrasonography. Preoperative, postoperative, and 1-month postoperative examinations were performed. The patients were divided into thrombosis and non-thrombosis groups according to ultrasonographic findings. A total of 404 patients were included in the study. The preoperative, postoperative, and 1-month postoperative incidence rates were, respectively, 35%, 55%, and 40% for DVT and 12%, 22%, and 20% for DVT in the uninjured contralateral lower extremity. The incidence of perioperative DVT decreased over time from 223 (55%) to 161 (40%). Multivariate analysis revealed that the independent risk factors for preoperative that of DVT were age (odds ratio [OR]: 1.03; 95% CI: 1.01-1.04; P = .000); postoperative that of DVT were age (OR: 1.04; 95% CI: 1.03-1.05; P = .000), blood loss (OR: 1.001; 95% CI: 1.000-1.002; P = .018), and American Society of Anesthesiologists classification (OR: 2.07; 95% CI: 1.16-3.72; P = .014); and 1-month postoperative that of DVT were age (OR: 1.05; 95% CI: 1.03-1.07; P = .000), respectively. In conclusion, the incidence of perioperative DVT decreased over time in patients who received anticoagulation treatment. Age was an important risk factor for perioperative DVT.

Deep Vein Thrombosis in the Uninjured Lower Extremity: A Retrospective Study of 1454 Patients With Lower Extremity Fractures

The purpose of this study was to identify patients at higher risk of deep venous thrombosis (DVT) in the uninjured lower extremity both preoperatively and postoperatively in patients with lower extremity fractures. We collected the clinical data of patients with lower extremities fractures who presented at Xi’an Honghui Hospital between 1 July, 2015 and 31 October, 2017. Doppler ultrasonography was used to diagnose the DVT. Patients were examined pre- and postoperatively. The patients were divided into thrombosis group and no thrombosis group according to the preoperative and postoperative ultrasonography results. The thrombosis group was defined as patients with DVT in the uninjured lower extremity and the no thrombosis group was defined as patients without DVT in the uninjured lower extremity. This study enrolled 1454 patients who met the inclusion criteria. The incidence of preoperative DVT in the uninjured lower extremity was 9.63% whereas the postoperative incidence was 20.29%. Age (OR = 0.965, 95 CI%: 0.954-0.977; P ≤ 0.001) and female (OR = 0.667, 95% CI: 0.451-0.986, P = 0.042) were independent risk factors for preoperative DVT in the uninjured lower extremity. Blood loss (OR = 0.997, 95 CI%: 0.995-1.000; P = 0.020), D-dimer level at admission (OR = 0.941, 95 CI%: 0.887-0.999; P = 0.045), and postoperative day 5 D-dimer level (OR = 0.889, 95 CI%: 0.819-0.965; P = 0.005), were independent risk factors for postoperative DVT in the uninjured lower extremity. For the patients with lower extremity fractures, age and female were associated with the preoperative DVT in the uninjured lower extremity. Blood loss, D-dimer at admission and postoperative day 5 D-dimer were associated with the postoperative DVT in the uninjured lower extremity.

Deep venous thrombosis after Achilles tendon rupture is associated with poor patient-reported outcome

PURPOSE

The aim of this study was to investigate whether patient subjective and functional outcomes after Achilles tendon rupture (ATR) are related to deep venous thrombosis (DVT) during leg immobilization.

METHODS

A cohort study with prospectively collected randomized data was conducted between 2010 and 2017. Two-hundred and fifty-one Patients with an Achilles tendon rupture (mean age = 41 ± 8), treated with uniform surgical techniques, were retrospectively analyzed. DVT incidence at 2 and 6 weeks was assessed using compression duplex ultrasound. At 12 months patient-reported outcomes were assessed using the Achilles tendon Total Rupture Score (ATRS), Foot- and Ankle Outcome Score (FAOS), Physical Activity Scale (PAS) and functional outcome with the calf-muscle endurance test. ANOVA analyses were used and adjusted for assumed confounding factors (patient age, sex, BMI and rehabilitation).

RESULTS

The total DVT incidence was 122 out of 251 (49%). Patients suffering a DVT exhibited significantly lower ATRS at 1 year compared to patients without DVT (mean 76 vs 83, 95% CI 71-79 vs 80-87; p < 0.01). Sixty-seven percent (95% CI 57-77%) of the patients devoid of DVT reported a good outcome (ATRS > 80) compared to 51% (95% CI 41-61%) of the patients sustaining a DVT (p < 0.05). Quality of life displayed significantly better outcome in the non-DVT versus DVT patients (mean = 75 (95% CI 71-79) vs. mean = 68 (95% CI 64-72); p < 0.05). A significant difference in total concentric work was observed between non-DVT and DVT patients (median = 1.9 kJ (IQR = 0.9 kJ) vs. median = 1.6 kJ (IQR = 1.0 kJ); p < 0.01).

CONCLUSION

Sustaining a DVT during leg immobilization significantly impairs patient-reported outcome at 1 year after surgical repair of ATR.

LEVEL OF EVIDENCE

III.

Risk assessment and management of preoperative venous thromboembolism following femoral neck fracture

BACKGROUND

Limited studies are available to investigate the prevalence of preoperative venous thromboembolism (VTE) in elderly patients with femoral neck fractures. Our primary aim was to determine the incidences of VTE and its risk or protective factors in such patient population. The secondary objective was to evaluate the need of therapeutic anticoagulation for isolated calf muscular venous thrombosis (ICMVT) prior to femoral neck fracture surgery.

METHODS

This is a retrospective case-control study, including 301 femoral neck fracture patients who were admitted to our institution between January 2014 and March 2017. Bilateral Doppler ultrasonography was performed in each of the patients as a preoperative VTE screening. The event rate of VTE was calculated, and significant risk or protective factors were determined by using a multivariate logistic regression model. Patients with ICMVT were divided into anticoagulation and no anticoagulation groups to assess the efficacy and safety of preoperative therapeutic anticoagulation. Intraoperative blood loss, drainage volume, blood transfusion, perioperative hemoglobin change, and rate of thrombosis extension were compared between the two groups.

RESULTS

The overall preoperative incidence of VTE in patients with femoral neck fracture was 18.9% (57/301), in which deep vein thrombosis (DVT) was 18.9% and pulmonary embolism (PE) was 1%. Among the DVT cases, 77.2% (44/57) were ICMVTs. Multiple fractures (odds ratio [OR] = 9.418; 95% confidence interval [CI] = 2.537 to 34.96), coexisting movement disorder (OR = 3.862; 95% CI = 1.658 to 8.993), bed rest for more than 7 days (OR = 2.082; 95% CI = 1.011 to 4.284) as well as elevated levels of D-dimer (OR = 1.019; 95% CI = 1.002 to 1.037) and fibrinogen (OR = 1.345; 95% CI = 1.008 to 1.796) led to an increase in the risk of VTE, while the recent use of antiplatelet drug (OR = 0.424; 95% CI = 0.181 to 0.995) and prophylactic anticoagulation (OR = 0.503; 95% CI = 0.263 to 0.959) decreased the risk of VTE. For the 39 patients with ICMVT undergoing femoral neck fracture surgery, there were no significant differences in the rate of thrombosis extension between anticoagulation and no anticoagulation groups, but significantly decreased postoperative hemoglobin was observed in the anticoagulation group.

CONCLUSION

Our findings showed a high prevalence of preoperative VTE in elderly patients with femoral neck fracture, with risk factors identified. We found that the most detected VTE were ICMVTs. Our study suggested that a direct surgery without preoperative use of therapeutic anticoagulation for ICMVT would not reduce the risk of thrombus extension, and the therapeutic use of anticoagulation may worsen postoperative anemia.

[Occurrence of Venous Thromboembolism in Patients with Lung Cancer and Its Anticoagulant Therapy]

目前，肺癌的发病率和死亡率在全世界范围内居首位。静脉血栓栓塞症（venous thromboembolism, VTE）是一种公认的肺癌并发症，也是肺癌患者的主要死因之一。癌症自身因素、患者自身因素以及治疗相关因素都是导致肺癌患者发生VTE的主要原因。肿瘤细胞可产生组织因子（tissue factor, TF）、癌性促凝物质（cancer procoagulant, CP）、炎症因子和细胞因子，从而直接激活凝血；其中TF过度表达是肿瘤患者血栓形成的主要机制之一。2016年美国胸外科医师协会（American College of Chest Physicians, ACCP）发布的第10版肿瘤患者VTE防治指南（AT-10）指出，抗凝治疗是肺癌患者合并VTE的基本治疗措施；其中低分子肝素（low molecular-weight-heparin, LWMH）被认为是首选的抗凝药物，但要注意出血风险。

Deep vein thrombosis in bilateral lower extremities after hip fracture: a retrospective study of 463 patients

Objective

To investigate the incidences of deep vein thrombosis (DVT) before and after operation in inpatients with hip fractures in both lower extremities.

Patients and methods

We collected the clinical data of 463 patients with lower extremities fractures who presented at Xi'an Honghui Hospital between July 1, 2014, and October 31, 2016 and met all the inclusion criteria. Doppler ultrasonography was used to diagnose DVT. The patients were examined preoperatively and postoperatively and divided into the thrombosis and non-thrombosis group according to the ultrasonographic findings. We divided the DVT cases into central, peripheral, and mixed thromboses.

Results

The incidence of preoperative DVT was 34.98%, and the prevalence of DVT on the uninjured side was 13.60%. This composition ratio increased to 57.23% postoperatively, and the prevalence of DVT on the uninjured side was 25.05%. Age (odds ratio [OR], 1.03; 95% CI: 1.01-1.04; P=0.002), venous thrombosis at admission (OR, 4.05; 95% CI, 2.30-7.13; P=0.000), and the days between the fracture and the operation (OR, 1.10; 95% CI, 1.02-1.20; P=0.020) were the independent risk factors of preoperative DVT. Coronary heart disease (OR, 1.85; 95% CI: 1.18-2.89; P=0.007), venous thrombosis at admission (OR, 22.35; 95% CI: 6.78-73.60; P=0.000), days between fracture and operation (OR, 1.06; 95% CI: 1.01-1.11; P=0.021), and blood loss (OR, 1.002; 95% CI: 1.000-1.003; P=0.014) were independent risk factors of postoperative DVT.

Conclusion

The actual incidence of DVT after hip fracture may be underestimated. The incidences of preoperative and postoperative DVTs and the incidence of DVT on the uninjured limb were high.

Qualitative Slow Blood Flow in Lower Extremity Deep Veins on Doppler Sonography: Quantitative Assessment and Preliminary Evaluation of Correlation With Subsequent Deep Venous Thrombosis Development in a Tertiary Care Oncology Center

OBJECTIVES

To determine whether the qualitative sonographic appearance of slow deep venous flow in the lower extremities correlates with quantitative slow flow and an increased risk of deep venous thrombosis (DVT) in oncology patients.

METHODS

In this Institutional Review Board-approved retrospective study, we reviewed lower extremity venous Doppler sonographic examinations of 975 consecutive patients: 482 with slow flow and 493 with normal flow. The subjective slow venous flow and absence of initial DVT were confirmed by 2 radiologists. Peak velocities were recorded at 3 levels. Each patient was followed for DVT development. The associations between DVT and the presence of slow venous flow were examined by the Fisher exact test; a 2-sample t test was used for peak velocity and DVT group comparisons. The optimal cutoff peak velocity for correlation with the radiologists' perceived slow flow was determined by the Youden index.

RESULTS

Deep venous thrombosis development in the slow-flow group (21 of 482 [4.36%]) was almost doubled compared with patients who had normal flow (11 of 493 [2.23%]; P = .0456). Measured peak venous velocities were lower in the slow-venous flow group (P < .001). Patients with subsequent DVT did not have a significant difference in venous velocities compared with their respective patient groups. The sum of 3 venous level velocities resulted in the best cutoff for dichotomizing groups into normal versus slow venous flow.

CONCLUSIONS

Qualitative slow venous flow in the lower extremities on Doppler sonography accurately correlates with quantitatively slower flow, and this preliminary evaluation suggests an associated mildly increased rate of subsequent DVT development in oncology patients.

Anticoagulation in patients with isolated distal deep vein thrombosis: a meta-analysis

Essentials The optimal management of isolated distal deep vein thrombosis (IDDVT) is undefined. This meta-analysis aimed to assess the clinical benefit of anticoagulation for IDDVT. Anticoagulation reduced the rate of pulmonary embolism without increasing major bleeding risk. Recurrent thromboembolism was less common with more than 6 weeks vs. 6 weeks of anticoagulation.

SUMMARY

Background The optimal management of patients with isolated distal deep vein thrombosis (IDDVT), concerning both the need for anticoagulation and its duration, is undefined. Objectives We performed a meta-analysis of randomized and cohort studies in patients with IDDVT to assess the clinical benefit of: (i) anticoagulation versus no anticoagulation; and (ii) anticoagulant treatment for 6 weeks versus for > 6 weeks. Methods The primary outcome of this analysis was recurrent venous thromboembolism (proximal propagation, recurrence of deep vein thrombosis, and pulmonary embolism). Data were pooled and compared by the use of odds ratio (OR) and 95% confidence interval (CI). Results A reduction in the rate of recurrent venous thromboembolism was observed in patients who received anticoagulation relative to those who did not receive anticoagulation (either therapeutic or prophylactic) (20 studies, 2936 patients; OR 0.50, 95% CI 0.31-0.79), without an increase in the risk of major bleeding (OR 0.64, 95% CI 0.15-2.73). The rate of pulmonary embolism was lower in anticoagulant-treated patients than in controls (15 studies, 1997 patients; OR 0.48, 95% CI 0.25-0.91). A lower rate of recurrent venous thromboembolism was observed in patients who received > 6 weeks of anticoagulant therapy than in those who received 6 weeks of anticoagulant therapy (four studies, 1136 patients; OR 0.39, 95% CI 0.17-0.90). Conclusions In patients with IDDVT, anticoagulation (both therapeutic and prophylactic) reduces the rate of recurrent venous thromboembolism and the incidence of pulmonary embolism as compared with no anticoagulation, without an increased risk of major bleeding. Anticoagulation for > 6 weeks should be preferred over shorter durations.

Current management of isolated soleal and gastrocnemius vein thrombosis

Thrombi of the soleal and gastrocnemius veins of the leg remain incompletely characterized in terms of the appropriate treatment algorithm to follow. Although they are anatomically located below the level of the fascia, making them "deep" vein thrombi, their natural history is unclear with respect to propagation and embolization. Varying treatment suggestions have been proposed, from full-dose anticoagulation to "watchful waiting" with repeated duplex examination, with none rising to the level of accepted scientific evidence. Herein, we present the current literature citing the differing opinions and data that have confused the subject.