Hemodynamic Study on the Relationship Between Collateral Circulation Caused by Iliac Vein Compression and Deep Venous Thrombosis / 医用生物力学

Objective To explore the relationship between the establishment of collateral circulation caused by iliac vein compression syndrom(IVCS) and the deep venous thrombosis (DVT). Methods Different types of ideal collateral circulation models and IVCS patient-specific models were numerically simulated using computational fluid dynamics (CFD) in combination with the blood stasis model. The relationship between blood retention and collateral types and cross-sectional area was studied, and the relationship with thrombosis was explored. Results Wall shear stress (WSS) at the distal end part of each ideal model was 0.3 Pa. After four cardiac cycles, the residual blood stayed at the stenosis and the distal end part for the lumbar ascending and pelvic type models, the old blood volume fraction (OBVF) varied with collateral cross-sectional areas, ranging from 5%-90% and 70%-80%, respectively. The OBVF of the coexistence model was above 80%. The WSS at the distal end part of the patient-specific model was 0.9 Pa, and the OBVF at the distal end part was 51.5%. Conclusions The stenosis and the distal end part are most prone to blood stasis, and closely related with DVT. The larger the collateral cross-sectional area, the more serious the blood stagnation. Blood stagnation of the coexistence model is higher compared with the model with lumbar ascending type and pelvic type.

Enfermedad tromboembólica venosa: factores de riesgo y profilaxis en pacientes hospitalizados / Venous thromboembolic disease: risk factors and prophylaxis in hospitalized patients

Un alto porcentaje de pacientes hospitalizados puede presentar trombosis venosa profunda con sus corresponientes consecuencias. Objetivos: Determinar el riesgo y tratamiento profiláctico de enfermedad tromboembólica venosa (ETEV) en pacientes hospitalizados. Métodos:investigación de tipo observacional, transversal y multicéntrica. Se aplicó la escala de Caprini para identificar factores de riesgo en pacientes hospitalizados de cuatro hospitales del área Metropolitana de Caracas. Por otra parte, se aplicó una encuesta a médicos residentes y especialistas de las distintas sedes hospitalarias para determinar su conocimiento en profilaxis para ETEV. Resultados: Se registraron 851 pacientes hospitalizados con edad 48,6 + 19,3 años, con predominio del género masculino (59 %). Estaban en servicios quirúrgicos 489 pacientes (57,5 %) y servicios médicos 362 pacientes (42,5 %). Según la escala de Caprini 154 pacientes (18,1 %) estaban en riesgo moderado, y 642 pacientes (75,4 %) en riesgo alto. Recibieron tratamiento profiláctico 61 pacientes (7,7 %), siendo la medicación y la dosis adecuada solo en el 32,8 % de estos pacientes. En cuanto al conocimiento de ETEV, el 96,9 % de los médicos conoce la enfermedad, pero solo el 58,5 % reconoce la embolia pulmonar como parte de esta entidad. Solo el 49,2 % de los encuestados conoce o aplica escalas de riesgo para esta enfermedad. El tratamiento farmacológico es conocido por el 93,8 % de los médicos. Solo el 56,6 % de los médicos realiza seguimiento a los pacientes, siendo el lapso menor de 3 meses el más frecuente (40 %). Conclusiones: en nuestro estudio hay predominio de pacientes con alto riesgo para ETEV. El uso de profilaxis farmacológica es muy bajo. El conocimiento de escalas de riesgo no es adecuado(AU)

Venous thromboembolic disease is frequent in hospitalized patients.Objectives: To determine the risk and prophylactic therapy of venous thromboembolic disease (VTE) in patients with medical and surgical pathologies according to the Caprini scale. Methods: an observational, transversal and multicenter research was performed. The Caprini scale was applied to identify risk factors in medical and surgical hospitalized patients of four hospitals in the metropolitan area of Caracas. Also, a survey was applied to residents and specialists from the different hospitals to determine the knowledge about prophylactic treatment for VTE. Results: we registered 851 hospitalized patients with an age of 48,6 + 19,3 years, mainly men (59 %). There were 489 surgical patients (57,5 %) and 362 medical patients (42,5 %). According to Caprini risk scale 154 patients (18,1 %) were at middle risk and 642 patients (75,4 %) were at high risk. Prophylactic treatment was indicated in 61 patients (7,7 %), this treatment was adequate (doses and drug type) only in 32 % of these patients. About the ETV, 96,9 % of the medical doctors had knowledge of this illness, but only 58,5 % recognize pulmonary embolism as part of this entity. Only 49,2 % knows or applies risk scales for ETV. 56,6 % follows the patients, more frequently for less of 3 months (40 %). Conclusions: we found is a high predominance of moderate to high risk patients for ETV. Pharmacological prophylaxis was very low. ETV risk scales knowlegde is not adequate(AU)

Application Status and Biomechanical Research Progress of Vena Cava Filter / 医用生物力学

Vena cava filter was widely used in clinic to prevent pulmonary embolism in treating lower extremity deep venous thrombosis（DVT）. In this paper, application status of vena cava filter was reviewed, including the way of vena cava filter implantation, filter classification, indications of filter implantation and existing problems (contraindications and complications). The frontier issues concerning study on novel filters, such as the degradation filter and drug coated filter was also analyzed, and the hemodynamic research progress from domestic scholars in recent years about filter structure was briefly summarized. The research findings provide references for further optimization of filter structure and clinical application of vena cava filter.

Relationship between deep venous thrombosis and inflammatory cytokines in postoperative patients with malignant abdominal tumors

Deep venous thrombosis (DVT) is a common surgical complication in cancer patients and evidence that inflammation plays a role in the occurrence of DVT is increasing. We studied a population of cancer patients with abdominal malignancies with the aim of investigating whether the levels of circulating inflammatory cytokines were associated with postoperative DVT, and to determine the levels in DVT diagnoses. The serum levels of C-reactive protein (CRP), interleukins (IL)-6 and IL-10, nuclear transcription factor-κB (NF-κB) and E-selectin (E-Sel) were determined in 120 individuals, who were divided into 3 groups: healthy controls, patients with and patients without DVT after surgery for an abdominal malignancy. Data were analyzed by ANOVA, Dunnet's T3 test, chi-square test, and univariate and multivariate logistic regression as needed. The CRP, IL-6, NF-κB, and E-Sel levels in patients with DVT were significantly higher than those in the other groups (P<0.05). The IL-10 level was higher in patients with DVT than in controls but lower than in patients without DVT. Univariate analysis revealed that CRP, IL-6, NF-κB, and E-Sel were statistically associated with the risk of DVT (OR=1.98, P=0.002; OR=1.17, P=0.000; OR=1.03, P=0.042; and OR=1.38, P=0.003; respectively), whereas IL-10 had a protective effect (OR=0.94, P=0.011). Multivariate analysis showed that E-Sel was an independent risk factor (OR=1.41, P=0.000). Thus, this study indicated that an increased serum level of E-Sel was associated with increased DVT risk in postoperative patients with abdominal malignancy, indicating that E-Sel may be a useful predictor of diagnosis of DVT.

Clincal treatment of lower extremity deep venous thrombosis / 重庆医科大学学报

0.05),but those of the two groups were better than the anticongulation group(P

A medium-term follow-up for deep venous thrombosis after total knee arthroplasty / 中华创伤骨科杂志

Objective To report the medium-term follow-up results for deep venous thrombosis(DVT) after total knee arthroplasty(TKA).Methods Between July 2003 and March 2004,55 patients(63 knees)who had had TKA were followed up for DVT.In follow-ups 1 to 2 weeks after TKA,their clinic symptoms,Doppler ultrasonograms and venograms were analyzed.In the following out-patient follow-ups done at every six months,we observed their clinic symptoms and Doppler uhrasonograms for the operated lower extremity.Venography was done only for those who had severe DVT symptoms.Results The venography one week after TKA conformed that DVT occurred in 34 patients(41 knees,61.8%).Two weeks after operation,DVT vanished in 12 cases,but deterio- rated to the proximal part in two cases.The follow-ups averaged 36.6 months(range,32 to 40 months).The results at five time points showed that the incidence of DVT did no decrease with lapse of time(P＞0.05).Conclusion No matter whether DVT occurs in the perioperative period,incidence of DVT in the medium term varies little.