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Concept: Deep vein

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The Italian Registry of Thrombosis in Children (RITI) was established by a multidisciplinary team with the aims of improving knowledge about neonatal and paediatric thrombotic events in Italy and providing a preliminary source of data for the future development of specific clinical trials and diagnostic-therapeutic protocols.

Concepts: Blood, Thrombosis, ClinicalTrials.gov, Hematology, Vein, Deep vein, Plato

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BACKGROUND: Peripherally inserted central catheters (PICCs) are associated with an increased risk of venous thromboembolism. However, the size of this risk relative to that associated with other central venous catheters (CVCs) is unknown. We did a systematic review and meta-analysis to compare the risk of venous thromboembolism associated with PICCs versus that associated with other CVCs. METHODS: We searched several databases, including Medline, Embase, Biosis, Cochrane Central Register of Controlled Trials, Conference Papers Index, and Scopus. Additional studies were identified through hand searches of bibliographies and internet searches, and we contacted study authors to obtain unpublished data. All human studies published in full text, abstract, or poster form were eligible for inclusion. All studies were of adult patients aged at least 18 years who underwent insertion of a PICC. Studies were assessed with the Newcastle-Ottawa risk of bias scale. In studies without a comparison group, the pooled frequency of venous thromboembolism was calculated for patients receiving PICCs. In studies comparing PICCs with other CVCs, summary odds ratios (ORs) were calculated with a random effects meta-analysis. FINDINGS: Of the 533 citations identified, 64 studies (12 with a comparison group and 52 without) including 29 503 patients met the eligibility criteria. In the non-comparison studies, the weighted frequency of PICC-related deep vein thrombosis was highest in patients who were critically ill (13·91%, 95% CI 7·68-20·14) and those with cancer (6·67%, 4·69-8·64). Our meta-analysis of 11 studies comparing the risk of deep vein thrombosis related to PICCs with that related to CVCs showed that PICCs were associated with an increased risk of deep vein thrombosis (OR 2·55, 1·54-4·23, p<0·0001) but not pulmonary embolism (no events). With the baseline PICC-related deep vein thrombosis rate of 2·7% and pooled OR of 2·55, the number needed to harm relative to CVCs was 26 (95% CI 13-71). INTERPRETATION: PICCs are associated with a higher risk of deep vein thrombosis than are CVCs, especially in patients who are critically ill or those with a malignancy. The decision to insert PICCs should be guided by weighing of the risk of thrombosis against the benefit provided by these devices. FUNDING: None.

Concepts: Blood, Thrombosis, Hematology, Vein, Low molecular weight heparin, Central venous catheter, Deep vein thrombosis, Deep vein

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Purpose: Early detection of deep vein thrombosis (DVT) is critical to prevent clinical pulmonary thromboembolism. However, most conventional methods for diagnosing DVT are functionally limited and complicated. The aim of this study was to evaluate the value of infrared-thermal-imaging (IRTI), a novel imaging detection or screening technique, in diagnosis of DVT in animal models.Methods: DVT model of femoral veins was established in nine New Zealand rabbits. The right hind femoral vein was embolized and the contralateral one served as a nonembolized control. Measurements of IRTI, compression ultrasonography (CPUS), and angiography under ultrasonic observation (AGUO) were performed at three time points: T1 (baseline, 10 min prior to surgery), T2 (2 h after thrombin injection), and T3 (48 h postoperatively). Qualitative pseudocolor analysis and quantitative temperature analysis were performed based on mean area temperature (Tav) and mean curvilinear temperature (Tca) of the region of interest as shown in IRTI. Temperature differences (TD) in Tav (TD(Tav)) and Tca (TD(Tca)) between the DVT and control sides were computed. Comparative statistical analysis was carried out by paired t-test and repeated measure, while multiple comparisons were performed by using Greenhouse-Geisser and Bonferroni approach. Values of P < 0.05 and P < 0.01 were considered statistically significant and highly significant.Results: Modeling of DVT was successful in all rabbits, as confirmed by CPUS and AGUO and immediately detected by IRTI. IRTI qualitative analysis of pseudocolor revealed that the bilateral temperatures were apparently asymmetrical and that there were abnormally high temperature zones on the DVT side where thrombosis formed. The results of paired t-test of Tav and Tca between DVT side and control sides did not reveal statistical difference at T1 (Tav: P = 0.817; Tca: P = 0.983) yet showed statistical differences at both T2 (Tav: P = 0.023; Tca: P = 0.021) and T3 (Tav: P = 0.016; Tca: P = 0.028). Results of repeated measure and multiple comparisons of TD(Tav) and TD(Tca) were highly different and significant differences across the T2 (TD(Tav): P = 0.009; TD(Tav): P = 0.03) and T3 (TD(Tav): P = 0.015; TD(Tav): P = 0.021).Conclusions: IRTI temperature quantitative analysis may help further detection of DVT. Additionally, IRTI could serve as a novel detection and screening tool for DVT due to its convenience, rapid response, and high sensitivity.

Concepts: Scientific method, Statistics, Statistical significance, Vein, Femoral vein, Deep vein thrombosis, Deep vein, Profunda femoris vein

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The exclusion of deep venous thrombosis (DVT) in the elderly is hampered by low specificity in clinical decision of D-dimer assays in older patients. To reduce false-positive results, we evaluated specific fibrin(ogen) degradation product assays for their contribution in the diagnosis of DVT. In a post-hoc study with outpatients suspected for DVT, we evaluated the elastase-specific fibrinogen (fibrinogen elastase degradation product, FgEDP) and D-E-specific fibrin (fibrin degradation product, FbDP) degradation product assays in relation to DVT. Results were combined with five D-dimer assays as ratio, with a specific focus on age-dependency. In 437 patients (DVT prevalence 39%), FgEDP correlated with D-dimer in DVT-negative patients (P < 0.001), but not in DVT-positive patients (P > 0.55). FbDP results correlated with D-dimer in both groups (P < 0.001). The values of the area under the curve of the receiver operating characteristic curve for both assays were lower than D-dimer. Using the ratios, only in the fourth age quartile D-dimer/FgEDP ratios had diagnostic value with lower number needed to test (1.8-12.7) as compared to D-dimer less than 500 μg/l alone (5.4-102). The D-dimer/FbDP ratios in DVT-negative elderly patients increased to a plateau by increasing D-dimer. In DVT-positive patients, these ratios were near constant for increasing values of D-dimer. In elderly patients, the D-dimer/FgEDP ratios may improve the number of patients in whom DVT could be excluded. The D-dimer/FbDP ratios showed differences in composition of fibrin degradation products between DVT-negative and DVT-positive patients and between young and old DVT-negative patients.

Concepts: Hematology, Vein, Receiver operating characteristic, Deep vein thrombosis, Deep vein, D-dimer, Coagulation system, Fibrin degradation product

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Introduction: In this study the angiogenetic effect of sintered 45S5 Bioglass® was quantitatively assessed for the first time in the arteriovenous loop model. Materials and Methods: An arteriovenous loop was created by interposition of a venous graft from the contralateral side between the femoral artery and vein in the medial thigh of 8 rats. The loop was placed in a teflon isolation chamber and was embedded in a sintered 45S5 Bioglass® granula matrix filled with fibrin gel. Specimens were investigated three weeks postoperatively by means of micro-computed tomography, histological and morphometrical techniques. Results: All animals tolerated the operations well. At 3 weeks both, micro-computed tomography and histology demonstrated a dense network of newly formed vessels originating from the AV loop. All constructs were filled with cell-rich, highly vascularised connective tissue around the vascular axis. Analysis of vessel diameter revealed constant small vessel diameters indicating immature new vessel sprouts. Conclusion: This study shows for the first time axial vascularization of a sintered 45S5 Bioglass® granula matrix. After three weeks the newly generated vascular network already interfused most parts of the scaffolds and showed signs of immaturity. The intrinsic type of vascularisation allows transplantation of the entire construct using the AV loop pedicle.

Concepts: Blood, Blood vessel, Histology, Artery, Vein, Circle, Femoral artery, Deep vein

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Venous thromboembolism is a relatively rare but serious complication of abdominal surgery. This study evaluated the incidence and risk factors for the development of deep venous thrombosis (DVT) after abdominal oncologic surgery using color Doppler ultrasonography (DUS).

Concepts: Medical ultrasound, Stroke, Hematology, Vein, Medical ultrasonography, Low molecular weight heparin, Deep vein thrombosis, Deep vein

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BACKGROUND: Endovenous Laser Ablation (EVLA) is one of the most accepted treatment options for varicose veins. The aim of this study was to investigate the efficacy and safety of the new radial fiber slim (ELVeS-radial-slim kit™) for the 1470 nm diode laser in perforator veins with a 1 month follow-up. METHODS: Our prospective observational cohort study comprised 69 perforating veins in 55 patients. Ninety percent of all patients were in the CEAP-stage C3-C6. The radial fiber slim was used to occlude the perforating vein and the great or small saphenous vein in the same procedure. The primary efficacy endpoint of the study was ultrasonographically proven elimination of venous reflux in the perforating vein after at least one month. Secondary efficacy and further safety end points after one month were as follows: (1) sonographic exclusion of recanalization of the treated vein segments, (2) deep vein thrombosis (DVT), clinical pulmonary embolism (PE), or superficial vein thrombosis (SVT) as defined by objective testing, (3) death from any cause, (4) persistent clinical complaints such as pain and paresthesia. RESULTS: Follow-up could be completed in all patients. In all treated perforating varicose veins, occlusion with elimination of reflux could be demonstrated immediately after the procedure. After one month 95.6% of the treated veins were still occluded (67/69). During follow-up, we did not diagnose any DVT, PE or SVT in the area related to the treated perforating vein. No patient died. One patient reported paresthesia distally of the puncture site. CONCLUSION: Endovenous laser treatment of varicose perforating veins with 1470 nm diode laser using the radial fiber slim is effective and safe with low recanalization rates during 1-month follow-up.

Concepts: Vein, Great saphenous vein, Deep vein thrombosis, Deep vein, Vascular surgery, Varicose veins, Sclerotherapy, Superficial vein

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The factors that contribute to pulmonary embolism (PE), a potentially fatal complication of deep vein thrombosis (DVT), remain poorly understood. Whereas fibrin clot structure and functional properties have been implicated in the pathology of venous thromboembolism and the risk for cardiovascular complications, their significance in PE remain incomplete. Therefore we systematically compared and quantified clot formation and lysis time, plasminogen levels, viscoelastic properties, activated factor XIII crosslinking and fibrin clot structure in isolated DVT and PE subjects. Clots made from plasma of PE subjects showed faster clot lysis times with no differences in lag time, rate of clot formation or maximum absorbance of turbidity as compared to DVT. Differences in lysis times were not due to alterations in plasminogen levels. Compared with DVT, clots derived from PE subjects showed accelerated establishment of viscoelastic properties, documented by a decrease in lag time and an increase in the rate of viscoelastic property formation. The rate and extent of fibrin crosslinking by activated factor XIII were similar between clots from DVT and PE subjects. Evaluation by electron microscopy revealed that plasma fibrin clots from PE subjects exhibited lower fiber density compared to those from DVT subjects. These data suggest that clot structure and functional properties differ between DVT and PE subjects and provide insights into mechanisms that may regulate embolization.

Concepts: Pulmonary embolism, Fibrin, Fibrinolysis, Hematology, Thrombus, Vein, Deep vein thrombosis, Deep vein

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This study reviews the clinical and workforce impact of a suggested protocol designed for the management of suspected acute deep venous thrombosis (DVT) in patients seen after standard vascular laboratory business hours. The protocol included the use of Wells score, D-dimer and a single dose of therapeutic anticoagulant to defer venous duplex ultrasound (VDU) testing until routine business hours unless contraindicated. Information was collected on medical history, physical exam and the timing of any diagnostic studies and treatment provided. Over 15% of studies done after-hours were deemed unnecessary by our protocol and in every individual the results were negative for an acute DVT. There were no adverse events from a one-time dose of anticoagulant. Limiting emergency VDU coverage to evaluate for acute DVT based on a management protocol can eliminate unnecessary after-hours VDU testing without having a negative impact on patient care.

Concepts: Patient, Stroke, Pulmonary embolism, Hematology, Vein, Low molecular weight heparin, Deep vein thrombosis, Deep vein