Pathologies mimicking deep venous thrombosis of the legs : pictorial review of US findings : P27

Purpose: Precise diagnosis of DVT of the legs is a challenging problem, not only in front of suspicion of PE, but also in all status of leg pain, warmth and swelling. Clinical diagnosis has a low accuracy and further investigations are mandatory in order to diagnose DVT. Amongst the possible investigations, US has a high specificity and a good NPV. However, many pathologies unrelated to the veins may mimic the signs and symptoms of DVT and have to be recognized in order to make the correct diagnosis. The purpose of this paper is to review the results of the US investigations of the legs performed in our Department during the last three years for a suspicion of DVT and describe alternative diagnoses mimicking DVT. Methods and materials: Through a RIS-based search, we retrospectively reviewed all the cases of US of the legs performed in our Department between January 2006 and December 2008 for a suspicion of DVT. We selected the cases of positive findings unrelated to the veins and illustrated these findings with characteristic images. Results: 419 US of the legs were performed between December 2006 and December 2008 for a suspicion of DVT. Among these, 75 were positive for DVT, and 79 for alternative diagnosis. The most common alternative diagnosis was edema of the legs (31%), followed by hematoma (23%). Other findings were Baker cysts (13%), cellulitis (10%) and lymphoceles (5%). Rare diagnoses were arterio-venous malformations, pseudoaneurysms, pelvic masses, necrosing fasciitis, intramuscular abscesses, subcutaneous seromas, sarcoma and ganglion cysts. Conclusion: A greater knowledge of the US appearance of the pathologies mimicking DVT may help to make the correct diagnosis, avoiding further expensive investigations or inappropriate anticoagulant therapy.

Home versus in-hospital treatment of outpatients with acute deep venous thrombosis of the lower limbs.

BACKGROUND: Some physicians are still concerned about the safety of treatment at home of patients with acute deep venous thrombosis (DVT). METHODS: We used data from the RIETE (Registro Informatizado de la Enfermedad TromboEmbólica) registry to compare the outcomes in consecutive outpatients with acute lower limb DVT according to initial treatment at home or in the hospital. A propensity score-matching analysis was carried out with a logistic regression model. RESULTS: As of December 2012, 13,493 patients had been enrolled. Of these, 4456 (31%) were treated at home. Patients treated at home were more likely to be male and younger and to weigh more; they were less likely than those treated in the hospital to have chronic heart failure, lung disease, renal insufficiency, anemia, recent bleeding, immobilization, or cancer. During the first week of anticoagulation, 27 patients (0.20%) suffered pulmonary embolism (PE), 12 (0.09%) recurrent DVT, and 51 (0.38%) major bleeding; 80 (0.59%) died. When only patients treated at home were considered, 12 (0.27%) had PE, 4 (0.09%) had recurrent DVT, 6 (0.13%) bled, and 4 (0.09%) died (no fatal PE, 3 fatal bleeds). After propensity analysis, patients treated at home had a similar rate of venous thromboembolism recurrences and a lower rate of major bleeding (odds ratio, 0.4; 95% confidence interval, 0.1-1.0) or death (odds ratio, 0.2; 95% confidence interval, 0.1-0.7) within the first week compared with those treated in the hospital. CONCLUSIONS: In outpatients with DVT, home treatment was associated with a better outcome than treatment in the hospital. These data may help safely treat more DVT patients at home.

Mesenteric venous thrombosis: MDCT features according to the underlying etiology [C-463]

Purpose: To work out certain, well‑defined aetiologies frequently associated with mesenteric venous thrombosis (MVT) in order to predict a typical population at risk, since MVT is nowadays often incidentally detected on cross‑sectional imaging. To demonstrate the MDCT features, frequency and extent of associated bowel ischemia according to the underlying pathology. Methods and Materials: Our electronic database revealed 71 patients (25 women, mean age 55) with thrombosis of the superior and/or inferior mesenteric vein detected by MDCT between 2000 and 2008. Two radiologists jointly reviewed the corresponding MDCT features including intraluminal extension, underlying aetiology and associated bowel ischemia, if present. Results: MVT was associated with carcinoma in 31 (43.7%) patients (pancreas 21.1%, liver 9.9%, others 12.7%). Concomitant inflammation was seen in 15 (21.1%) patients (pancreatitis 11.3%, diverticulitis 4.2%, others 5.6%), whereas coagulation/hematologic disorders were found in 7 (9.9%) patients, liver cirrhosis in 6 (8.5%), mixed/miscellaneous causes in 5 (7%) and still unknown aetiologies in 5 patients (7%). MVT resulted from recent operations in 2 (2.8%) patients. MDCT features of venous bowel ischemia were present in 15 patients (21.1%). 46.5% of MVT were (sub)acute, while 53.5% chronic. The luminal extension was complete in 52.1%, subtotal (50% of lumen) in 22.5% and partial (50% of lumen) in 25.4% of patients, consisting either of blood clots (76.1%) or tumoral tissue (23.9%), the latter mainly due to pancreas adenocarcinoma (76.4%). Conclusion: MDCT features of MVT are seen with a wide range of underlying diseases. Signs of intestinal ischemia are infrequently associated, mostly occurring with coagulation/hematologic disorders (40%).

Mesenteric venous thrombosis : MDCT features according to the underlying etiology : P1

Purpose: To work out certain, well-defined aetiologies frequently associated with mesenteric venous thrombosis (MVT) in order to predict a typical population at risk, since MVT is nowadays often incidentally detected on cross-sectional imaging. To demonstrate the MDCT features, frequency and extent of associated bowel ischemia according to the underlying pathology. Methods and materials: Our electronic database revealed 71 patients (25 women, mean age 55) with thrombosis of the superior and/or inferior mesenteric vein detected by MDCT between 2000 and 2008. Two radiologists jointly reviewed the corresponding MDCT features including intraluminal extension, underlying aetiology and associated bowel ischemia, if present. Results: MVT was associated with carcinoma in 31 (43.7%) patients (pancreas 21.1%, liver 9.9%, others 12.7%). Concomitant inflammation was seen in 15 (21.1%) patients (pancreatitis 11.3%, diverticulitis 4.2%, others 5.6%), whereas coagulation/hematologic disorders were found in 7 (9.9%) patients, liver cirrhosis in 6 (8.5%), mixed/miscellaneous causes in 5 (7%) and still unknown aetiologies in 5 patients (7%). MVT resulted from recent operations in 2 (2.8%) patients. MDCT features of venous bowel ischemia were present in 15 patients (21.1%). 46.5% of MVT were (sub) acute, while 53.5% chronic. The luminal extension was complete in 52.1%, subtotal (>50% of lumen) in 22.5% and partial (<50% of lumen) in 25.4% of patients, consisting either of blood clots (76.1%) or tumoral tissue (23.9%), the latter mainly due to pancreas adenocarcinoma (76.4%). Conclusion: MDCT features of MVT are seen with a wide range of underlying diseases. Signs of intestinal ischemia are infrequently associated, mostly occurring with coagulation/hematologic disorders (40%).

Antithrombotic effect of Lonomia obliqua caterpillar bristle extract on experimental venous thrombosis

The venom of Lonomia obliqua caterpillar may induce a hemorrhagic syndrome in humans, and blood incoagulability by afibrinogenemia when intravenously injected in laboratory animals. The possible antithrombotic and thrombolytic activities of L. obliqua caterpillar bristle extract (LOCBE) were evaluated in this study. The minimal intravenous dose of the extract necessary to induce afibrinogenemia and anticoagulation was 3.0 and 10.0 µg protein/kg body weight for rabbits and rats, respectively. In rabbits, this dose induced total blood incoagulability for at least 10 h and did not reduce the weight of preformed venous thrombi, in contrast to streptokinase (30,000 IU/kg). In rats, pretreatment with 5.0 and 10.0 µg/kg LOCBE prevented the formation of thrombi induced by venous stasis or by injury to the venous endothelium. The dose of 5.0 µg/kg LOCBE did not modify blood coagulation assay parameters but increased bleeding time and decreased plasma factor XIII concentration. When the extract was administered to rats at the dose of 10.0 µg/kg, the blood was totally incoagulable for 6 h. These data show that LOCBE was effective in preventing experimental venous thrombosis in rats, justifying further studies using purified fractions of the extract to clarify the mechanisms of this effect.

Epidemiology of recurrent venous thrombosis

Venous thrombosis, including deep vein thrombosis and pulmonary embolism, is a common disease that frequently recurs. Recurrence can be prevented by anticoagulants, but this comes at the risk of bleeding. Therefore, assessment of the risk of recurrence is important to balance the risks and benefits of anticoagulant treatment. This review briefly outlines what is currently known about the epidemiology of recurrent venous thrombosis, and focuses in more detail on potential new risk factors for venous recurrence. The general implications of these findings in patient management are discussed.

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.

Combinations of low doses of unfractionated heparin and of low-molecular-weight heparin prevent experimental venous thrombosis

Synergism between low-molecular-weight heparin and low doses of unfractionated heparin (UH) enhancing anti-factor Xa activity and the release of tissue factor pathway inhibitor was observed. The aim of this study was to verify whether this association is effective in preventing experimental venous thrombosis. Seventy rats were allocated into 7 groups: the control group treated with distilled water, the H-350 group treated with UH 350 IU/kg, the E-2 group treated with enoxaparin 2 mg/kg, the H-175 group treated with UH 175 IU/kg, the E-1 group treated with enoxaparin 1 mg/kg, the H-175 + E-1 group treated with UH 175 IU/kg plus enoxaparin 1 mg/kg, and the H-100 + E-0.5 group treated with UH 100 IU/kg plus enoxaparin 0.5 mg/kg. Forty minutes after subcutaneous injection, thrombosis was induced in vena cava. Three hours later, if present, thrombi were withdrawn and weighed. Bleeding time, activated partial thromboplastin time, thrombin time (TT), and anti-factor Xa were measured at the beginning and end of the experiment. Fortyeight other animals were treated, but without inducing thrombus, and tests were performed 40 min after injection. Thrombus developed in 90.9% of control animals, 20% of the H-350 group, 22.2% of the E-2 group, 10% of the H-175 + E-1 group, and 30% of the H-100 + E-0.5 group; there was a difference between group C and the other groups. Only in the H-350 and H-175 + E-1 groups were TT and activated partial thromboplastin time prolonged in relation to control at the end of the experiment. Forty minutes after injection, TT was prolonged in the H-350 and H-175 + E-1 groups. In conclusion, combinations of low doses of low-molecular-weight heparin and low doses of UH were as effective as high doses of each one used alone in preventing thrombus development in rat vena cava. Copyright (c) 2005 S. Karger AG, Basel.

Antithrombotic effect of Lonomia obliqua caterpillar bristle extract on experimental venous thrombosis

The venom of Lonomia obliqua caterpillar may induce a hemorrhagic syndrome in humans, and blood incoagulability by afibrinogenemia when intravenously injected in laboratory animals. The possible antithrombotic and thrombolytic activities of L. obliqua caterpillar bristle extract (LOCBE) were evaluated in this study. The minimal intravenous dose of the extract necessary to induce afibrinogenemia and anticoagulation was 3.0 and 10.0 µg protein/kg body weight for rabbits and rats, respectively. In rabbits, this dose induced total blood incoagulability for at least 10 h and did not reduce the weight of preformed venous thrombi, in contrast to streptokinase (30,000 IU/kg). In rats, pretreatment with 5.0 and 10.0 µg/kg LOCBE prevented the formation of thrombi induced by venous stasis or by injury to the venous endothelium. The dose of 5.0 µg/kg LOCBE did not modify blood coagulation assay parameters but increased bleeding time and decreased plasma factor XIII concentration. When the extract was administered to rats at the dose of 10.0 µg/kg, the blood was totally incoagulable for 6 h. These data show that LOCBE was effective in preventing experimental venous thrombosis in rats, justifying further studies using purified fractions of the extract to clarify the mechanisms of this effect.

The frequency of 844ins68 mutation in the cystathionine beta-synthase gene is not increased in patients with venous thrombosis

Background and Objectives. A frequent mutation in the cystathionine beta-synthase (CBS) gene (844ins68, a 68-bp insertion in the coding region of exon 8) was recently discovered. In the present study we Investigated this mutation as a candidate risk factor for venous thrombosis.Design and Methods. The prevalence of the 844ins68 CBS mutation was determined in 101 patients with objectively diagnosed deep venous thrombosis and in 101 healthy controls matched for age, sex and race. PCR amplification of a DNA fragment containing exon 8 of the CBS gene was employed to determine the genotypes, Additionally, Bsrl restriction enzyme digestion of the PCR products was performed in all samples from carriers of the insertion, to test for concurrent presence of a second mutation (T833C) in the CBS gene.Results. The insertion was found in 21 out of 101 patients (20.8%; allele frequency 0.109) and in 20 out of 101 controls (19.8%; allele frequency 0.114), yielding a relative risk for venous thrombosis related to the 844ins68 CBS mutation close to 1.0. In addition, the T833C GBS mutation was detected in all alleles carrying the 844ins68 CBS insertion, confirming the co-inheritance of the two mutations.Interpretation and Conclusions. Our findings do not support the hypothesis that the 844ins68 mutation in the CBS gene is a genetic risk factor for venous thrombosis. (C)1998, Ferrata Storti Foundation.