Pathophysiology of Venous Thromboembolism with Respect to the Anatomical Features of the Deep Veins of Lower Limbs: A Review

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.

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.

β‑carotene attenuates muscle wasting in cancer cachexia by regulating myogenesis and muscle atrophy

Cancer cachexia is a metabolic disease involving multiple organs, which is accompanied by the depletion of muscle tissue and is associated with ~20% of cancer‑related deaths. Muscle wasting is a critical factor in cancer cachexia. β‑carotene (BC) has been shown to increase muscle mass and hypertrophy in healthy mice. However, its effects on muscle tissue dysregulation in cancer cachexia have yet to be studied. In the present study, 5‑week‑old male C57BL/6J mice were injected with 1x106 Lewis lung carcinoma (LLC) cells to induce cancer cachexia; then the mice were administered BC (4 or 8 mg/kg) for 22 days to assess its effects on muscle atrophy in the gastrocnemius muscles. The effects of BC on inflammatory cytokines, myogenesis and muscle atrophy were evaluated using C2C12 myotubes treated with LLC‑conditioned media. BC supplementation significantly suppressed tumor growth, inflammatory cytokines, and hepatic gluconeogenesis in the LLC‑induced cancer cachexia mouse model, while also improving muscle weight and grip strength. These effects are considered to be mediated by the PI3K/Akt pathway and through regulation of muscle atrophy. Moreover, BC treatment was associated with the recovery of LLC‑conditioned media‑induced muscle differentiation deficits and muscle atrophy in C2C12 myotubes. These findings indicate BC as a potential novel therapeutic agent for cancer cachexia.

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.

Development of Risk Prediction Model for Muscular Calf Vein Thrombosis with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Purpose

This study aims to establish a risk prediction model for muscular calf vein thrombosis (MCVT) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD).

Methods

The research sample consisted of 248 patients with AECOPD and all of them underwent vascular ultrasounds of both lower limbs in this retrospective study. Univariate analysis and multivariate logistic regression analysis were conducted on factors with significant group differences to screen for the independent risk factors of MCVT. A nomogram to predict the risk of MCVT was constructed and validated with bootstrap resampling.

Results

According to the exclusion criteria, 240 patients were included for analysis, divided into the MCVT group (n = 81) and the non-MCVT group (n = 159). Multivariate logistic regression analyses showed that hypertension, elevated MPV, reduced albumin (ALB), elevated D-dimer and bed rest ≥3 days were independent risk factors for MCVT in AECOPD. A nomogram model for predicting AECOPD with MCVT was established based on them. The area under the curve (AUC) of receiver operating characteristic (ROC) curve for the prediction model and the simplified Wells score was 0.784 (95% CI: 0.722–0.847) and 0.659 (95% CI: 0.583–0.735), respectively. The cut-off value and Youden index of prediction model were 0.248 and 0.454, respectively. At the same time, the sensitivity, specificity, positive predictive value, and negative predictive value of the prediction model were 85.9%, 59.5%, 84.6%, and 77.4%, respectively. The sensitivity and specificity of the simplified Wells score were 67.9% and 56.3%, respectively. Validation by the use of bootstrap resampling revealed optimal discrimination and calibration, and the decision analysis curve (DAC) suggested that this prediction model involved high clinical practicability.

Conclusion

We developed a nomogram that can predict the risk of MCVT for AECOPD patients. This model has the potential to assist clinicians in making treatment recommendations and formulating corresponding prevention measures.

Effects of leg compression and calf muscle contraction by active ankle motion on venous hemodynamics in sitting individuals

Objectives

To clarify the effects of compression and active ankle motion on venous hemodynamics in healthy sitting individuals.

Methods

In the sitting position, 14 participants performed plantar flexion and dorsiflexion of the ankle for 3 s each without compression. Changes in the calf volume were recorded using air plethysmography. Subsequently, the process was repeated with the application of tubular elastic bandage (TEB), followed by anti-thrombotic stocking (ATS).

Results

The median interface pressure at the calf was 16 mmHg with TEB and 21 mmHg with ATS. Without compression ( N), the median venous volume was 76 mL. This was reduced to 58 mL with TEB and 56 mL with ATS ( p < .01 vs. N for both). On the other hand, ejection volume by plantar flexion in N (27 mL) was not significantly changed with TEB (31 mL) or ATS (31 mL). Also, ejection volume by dorsiflexion in N (53 mL, p < .001 vs. plantar flexion) was not significantly changed with TEB (53 mL, p < .01 vs. plantar flexion) or ATS (41 mL, p < .05 vs. plantar flexion).

Conclusions

The venous volume, which is defined as the change in enclosed calf volume from elevation to dependency, in the sitting position reduced similarly with TEB and ATS; however, the ejection volumes did not change significantly. Dorsiflexion exerted a larger ejection volume than plantar flexion in the sitting position.

State-of-Art in the Age Determination of Venous Thromboembolism: A Systematic Review

Venous thromboembolism (VTE), consisting of deep vein thrombosis (DVT) and pulmonary embolism (PE), requires a forensic age determination to ascertain their causal relationship with recent events, such as trauma or medical treatment. The main objective of this systematic review is to identify the current state-of-the-art immunohistochemical methods for age determination of fatal VTE. A literature search was performed through different databases, according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Within the study, we have selected only cases represented by deceased patients for DVT and/or PTE in which thromboembolic material was collected during an autoptic examination and then subjected to a histological and an immunohistochemical investigation. Studies based on animal models were not included. We assessed bias risk. A database-based search produced a total of 19 articles. After excluding duplicate items from the selection, 14 articles were reviewed. Ten articles were excluded because they did not meet the inclusion criteria. The results have pointed out 4 studies that were included in the present analysis for a total of 157 samples of DVT and 171 PTE samples. These were analyzed using traditional histological and immunohistochemical techniques. The results must be interpreted with a critical eye because of their heterogeneity in terms of time, geography, and study design. The present review highlights the importance of associating specific immunohistochemical markers with a histological analysis for the timing of DVT/PTE fatal events. Further future experiences will hopefully endorse actual knowledge on the subject to increase the accuracy in the assessment of thrombus-embolus age.

Staged Endovascular Treatment for Symptomatic Occlusion Originating From the Intracranial Vertebral Arteries in the Early Non-acute Stage

Background: The ideal treatment for patients who survive from acute vertebrobasilar artery occlusion but develop aggressive ischemic events despite maximal medical therapy in the early non-acute stage is unknown. This paper reports the technical feasibility and outcome of staged endovascular treatment in a series of such patients with symptomatic intracranial vertebral artery occlusion.

Methods: Ten consecutive patients who presented with aggressive ischemic events in the early non-acute stage of intracranial vertebral artery occlusion from Jan 2015 to Nov 2020 were retrospectively reviewed. Among them, eight male and two female patients with a mean age of 66.7 years developed aggressive ischemic events, and the NIHSS score was elevated by a median of 7 points despite medical therapy. All patients received staged endovascular treatment 4–21 days from onset, at an average of 11 days. The strategy of staged treatment was as follows: first, a microwire was passed through the portion of the occlusion, which was then dilated with balloon inflation to maintain the perfusion above TICI grade 2b. Then, with the use of antiplatelet drugs, the residual intravascular thrombus was gradually eliminated by the continuous perfusion and an activated fibrinolytic system, leaving the residual stenosis. A second stage of angioplasty with stent implantation was subsequently performed if residual stenosis was ≥50%. The NIHSS scores and mRS scores were compared between pre- and post-endovascular treatment groups and in the follow-up period.

Results: Technical success was achieved in 9 patients who received staged endovascular treatment (perforation occurred in one patient during the first stage). The NIHSS scores were significantly improved, with a median score 7 points lower on discharge compared with the scores for the most severe status. Favorable outcomes with mRS score ≤ 2 were achieved in 7 and 9 patients at the 3-month follow-up and the latest follow-up, respectively, which was better than the preoperative status.

Conclusion: Staged endovascular treatment might be a safe, efficient, and viable option in carefully selected patients with symptomatic intracranial vertebral artery occlusion in the early non-acute stage. However, this needs to be confirmed by further investigation, preferably in a large, controlled setting.

Triaging deep vein thrombosis using ultrasonography after lower-extremity orthopedic surgery: analysis of a single-center experience

PURPOSE

This study aimed to stratify risk factors and vein levels for postoperative deep vein thrombosis (DVT) after lower-extremity orthopedic surgery.

METHODS

Ninety-nine patients who underwent Doppler ultrasonography after lower-extremity orthopedic surgery were enrolled. Medical records were reviewed for anesthesia duration, type of surgery, body weight, height, and cardiovascular risk factors (including history of smoking, diabetes mellitus or hypertension, blood pressure, and total cholesterol and high-density lipoprotein [HDL] cholesterol levels), and the DVT treatment. Ultrasound diagnosis of DVT was made according to a routine protocol. The relationships between selected factors and the presence of DVT were assessed using univariate and multivariate regression analyses.

RESULTS

Thirty-three (33%) patients were found to have calf DVT. The mean age, weight, and height of the non-DVT and postoperative DVT patients were 55.1 years versus 65.4 years, 70.5 kg versus 61.2 kg, and 163.3 cm versus 157.0 cm, respectively. Total cholesterol/HDL levels in the non-DVT and DVT patients were 70.6/20.7 mg/dL and 90.8/26.0 mg/dL, retrospectively. Systolic and diastolic blood pressure in the non-DVT and DVT patients were 133.6/80.2 mm Hg and 132.2/78.1 mmHg, respectively. The mean duration of anesthesia was 173.9 versus 199.9 minutes, and the operative time was 136.4 minutes versus 161.0 minutes. Older age (P=0.005) and lower body weight (P=0.002) were significantly associated with postoperative DVT. No other significant between-group differences were found (P>0.05). The patients with ultrasound-identified DVT received antithrombotic treatment. None of them had distant thromboembolism.

CONCLUSION

After lower-extremity orthopedic surgery, the calf veins in elderly patients with low body weight are susceptible to thrombosis; they would most likely benefit from postoperative ultrasonography.

Design of a Device for Lower Limb Prophylaxis and Exercise

The problem of immobility of legs leading to a potentially life threatening condition including deep venous thrombosis (DVT) is well known. The reduced mobility of leg affects a large number of patients in a wide range of clinical scenarios spanning from swelling of the legs to pulmonary embolism. In normal human beings, an elegant system of venous return, both active and passive is responsible for prevention of deep venous thrombosis. The paper proposes a prophylaxis and exercise device that mimics the natural principles of venous return to promote the blood flow. The device is based on electromechanical actuation, and simultaneous alternating compression mechanism, that is compact and, suitably form fitted in design and additionally requires no specialised training for the usage. The device was tested on a healthy volunteer on two different days and findings support the efficacy of the prophylaxis and exercise device in significantly improving the blood flow rate in the lower limb. The prototype device is considered as a major step towards designing a clinically validated lower limb device.

Clinical Study on the Screening of Lower Extremity Deep Venous Thrombosis by D-Dimer Combined with RAPT Score Among Orthopedic Trauma Patients

BACKGROUND

Among the causes of mortality in patients with lower extremity fracture following surgery, lower extremity deep venous thrombosis (DVT) is a leading one. To lower the morbidity and mortality, early screening and preventive anticoagulation therapy are essential in clinical study. Common screening methods, including risk prediction tools, imaging tests and D-dimer test, had various drawbacks. The study aimed to establish a new method, that is, D-dimer combined with Risk Assessment and Predictor Tool (RAPT) score, for screening the lower extremity DVT among patients with lower extremity fracture and evaluate its clinical value.

MATERIALS AND METHODS

The RAPT score, plasma D-dimer and lower extremity venous ultrasonography examination reports were collected from Department of Emergency Surgery & Orthopaedic Surgery from July 2019 to December 2019, and the data were analyzed retrospectively. Regarding the lower extremity venous ultrasonography examination report as the "gold standard" to determine whether DVT exists, the sensitivity, specificity and area under the curve (AUC) of RAPT score alone, plasma D-dimer alone and combination of them in screening lower extremity DVT were analyzed and evaluated.

RESULTS

197 patients were enrolled in the study. There were significant differences in D-dimer level and RAPT score between DVT group and non-DVT group (P < 0.01). The sensitivity, specificity and AUC of RAPT score and D-dimer in screening lower extremity DVT were 78.12%, 56.44%, 0.723 and 97.71%, 25.74%, 0.803, respectively. The optimal diagnostic value of D-dimer decided by Youden's index was 1.125 μg/ml. The sensitivity and specificity of the method by combining RAPT score with this new D-dimer threshold were 96.88% and 42.57%, respectively, and AUC was 0.812.

CONCLUSION

Higher diagnostic accuracy could be achieved by combining RAPT score with new D-dimer threshold. This novel diagnostic method is potential in the clinical diagnosis of DVT among orthopedic trauma patients.

A Case of Total Excision of a Thrombosed-Venous Aneurysm in the Sural Vein

Venous aneurysm (VA) is an uncommon vascular disease; however, VA, especially in the lower extremities, can lead to critical complications, such as pulmonary embolism (PE). We report a case with a VA located in the sural vein (SV), which did not lead to PE; however, it had the potential to cause PE. Therefore, we treated this VA by total excision. The popliteal vein (PV) is the most common VA location in the lower extremities, but SV is extremely rare. We should always be aware that, in addition to the PV, VAs may also occur in the SV.

Characteristics and risk factors of deep vein thrombosis in hemiplegic, healthy and bilateral limbs of hemiplegic patients: a 10-year retrospective study

Deep vein thrombosis (DVT) in hemiplegic patients mainly affects hemiplegic limbs, DVT can also occur only in healthy limbs, and some hemiplegic patients have DVT in both limbs. Characteristics and risk factors of DVT in hemiplegic, healthy, and bilateral limbs are unknown. To describe the proportion, risk factors, extent, and timing of DVT in hemiplegic, healthy and bilateral limbs. A 10-year retrospective review of consecutive patients was performed. DVT affected hemiplegic limbs in 34 (62%), healthy limbs in 11 (20%), and was bilateral in 10 (18%). DVT was more likely to develop in healthy limbs of hemiplegic patients without surgery (odds ratio (OR) 0.022; 95% confidence interval (CI) 0.001-0.922), and without diabetes (OR 0.023, 95% CI 0.001-0.853). Among the veins at the level of which DVT occurred, intermuscular veins represented 20 (45%) in hemiplegic, 5 (37%) in healthy, and 6 (74%) in bilateral limbs. The median time that DVT occurred after hemiplegia onset was 18 days (interquartile range [IQR] 9-79) in hemiplegic, 17 days (IQR 10-56) in healthy, and 21 days (IQR 8-27) in bilateral limbs. Early and effective prevention of DVT after surgery and optimal management of diabetes may reduce the risk of DVT in bilateral limbs. It's important to prevent proximal extension of calf vein DVT. DVT prophylaxis should be started early and continued for at least 3 weeks after hemiplegia onset.

Venous Thromboembolism: Role of the Clinical Laboratory in Diagnosis and Management

Background

Venous thromboembolism (VTE) is the third most common cause of cardiovascular illness and is projected to double in incidence by 2050. It is a spectrum of disease that includes deep venous thrombosis (DVT) and pulmonary embolism (PE). In February 2016, the American College of Chest Physicians provided updated management guidelines for DVT and PE to address some of the unresolved questions from the previous version and to provide recommendations related to newer anticoagulants.

Content

Here we review current concepts for screening, diagnosis, thromboprophylaxis, and management of DVT and PE. We also describe the management of VTE in acute, long-term, and extended phases of treatment. Thrombophilia testing is rarely necessary and should be used judiciously; the laboratory can serve an important role in preventing unnecessary testing. The direct oral anticoagulants are as effective as conventional treatment and are preferred agents except in the case of cancer. The initial management of PE should be based on risk stratification including the use of D-dimer testing. Thrombolysis is used in cases of hemodynamically unstable PE and not for low-risk patients who can be treated on an outpatient basis.

Summary

This review is intended to provide readers with updated guidelines for screening, testing, prophylaxis, and management from various organizations.

Isolated Distal Deep Vein Thrombus Detected before Orthopedic Surgery: Is Preoperative Anticoagulation Preferable?

Objective: We evaluate the efficacy of anticoagulant administration for isolated distal deep vein thrombus (IDDVT), detected before orthopedic surgery.

Materials and Methods: The study included 32 patients diagnosed with IDDVT before orthopedic surgery in our hospital between October 2011 and October 2017. They were divided into two groups: the ‘pre- and post-operative therapy group,’ who were administered anticoagulants both pre- and post-operatively, and the ‘post-operative therapy group,’ who were administered anticoagulants only after surgery due to risk of bleeding judged by an orthopedic surgeon. We compared the primary efficacy (change in IDDVT size) between the two groups.

Results: The proportion of patients with increased post-operative IDDVT sizes was significantly larger in the post-operatively treated group than in the pre- and post-operatively treated group (44.4% vs. 8.7%, p=0.026). No case demonstrated an IDDVT extension proximal to the popliteal vein or presented with symptomatic pulmonary thromboembolism in this study.

Conclusion: Based on our findings, we recommend that, in patients with IDDVT detected prior to orthopedic surgery and administered anticoagulant therapy only after the procedure because of a bleeding risk, a lower limb ultrasonography to re-evaluate the existing deep vein thrombus should be conducted before beginning rehabilitation.

Identification of Chinese Hospitalized Patients' Risk Profile for Venous Thromboembolism (DissolVE1): A Study Protocol of a Non-Interventional Registry Study

INTRODUCTION

Venous thromboembolism (VTE) is a frequent cause of hospitalization, mortality, and long-term adverse consequence among medical and surgical inpatients. The current study is performed to identify the prophylaxis of patients with VTE risk within the 6 weeks prior to the diagnosis of VTE, and the treatment pattern during 3 months after VTE diagnosis in Chinese patients hospitalized for surgeries or medical illness.

METHODS

This multicenter, non-interventional, observational registry plans to enroll 1200 patients from 40 centers in China. The study will retrospectively collect data from patients' hospitalization record within 6 weeks of VTE diagnosis and prospectively follow-up patients for 3 months (in four visits). The primary outcome is to determine the percentage of patients receiving adequate prophylaxis in patients hospitalized within 6 weeks before VTE diagnosis and treatment pattern within 3 months after VTE diagnosis. Important secondary endpoints include determining patients with risk of VTE in the hospital setting, risk factors for VTE, and cost analysis of VTE treatment.

EXPECTED OUTCOMES

The findings will determine the characteristics of VTE, its treatment practices, cost of treatment, and quality of life in patients; this information may help in building diagnostic and prophylaxis strategies for VTE in China.

TRIAL REGISTRATION

The study is registered in the Venous Thromboembolism Registry in China with study number DIREGL07581.

FUNDING

Sanofi China.

Great Saphenous Vein Flow Pattern as a Simple Ultrasonographic Sign of Early Recanalization of Deep Vein Thrombosis: A Case Series Report

We retrospectively examined patients with ultrasonographically occlusive acute proximal deep vein thrombosis (DVT). All patients were categorized into two groups on the basis of whether great saphenous vein (GSV) flow toward the common femoral vein was detected (flow [+]; n=10) or undetected (flow [−]; n=10). We investigated the relationship between the GSV flow pattern and DVT recanalization. Thrombus recanalization, which is defined as diameter reduction to lower than 40% of the vessel diameter, was confirmed in seven of the flow (+), and none of the flow (−). This study proposes that the GSV flow pattern may be a simple marker for the recanalization of proximal occlusive DVT.