Chronic DVT Research Articles

Abstract 148: Loss Of Tlr4 Signaling Inhibits Thrombus Resolution In A Non-monocyte Dependent Manner

Background: Loss of TLR4 signaling reduces Venous Thrombosis (VT) resolution. Leukocyte expression of TLR4 is elevated in humans undergoing acute to chronic DVT transformation. We hypothesized that TLR4 signaling in monocytes directs thrombus clearance. Methods: Wild type, Tlr4 -/- , LysM cre+/- Tlr4 fl/fl mice underwent VT via IVC stasis at 4/7/14d timepoints. Thrombi subtypes were identified by flow cytometry. Thrombus size was assessed, and fibrinolytic mediators were assayed in splenic/bone marrow Mφs. Whole blood from mice was stimulated with TLR2/4 and assayed for thrombolytic potential via HALO assay. Immunohistochemistry was performed for cellular infiltrate. Results: We observed elevated TLR4 cell surface expression on CD11b+/Ly6C- Mo/Mφ from wild type thrombi. Thrombus weight in Tlr4 -/ mice was elevated at 4d stasis, confirming impaired thrombus clearance. In basal conditions, circulating Mo/Mφ saw decreased Urokinase & MMP9 mRNA levels in LysM cre+/- mice. In post thrombotic conditions, we saw decreased protein levels of Urokinase and MMP9 in Cre+ bone marrow-derived Mφs. Whole blood thrombolysis efficiency increased with TLR4 agonism in Cre- mice compared to Cre+. Efficiency was restored with LPS-mediated dual TLR2/4 agonism. Total thrombus weight was unchanged. No difference was identified in monocyte infiltrate into the thrombus (Fig. 1) Conclusions: Genetic deficiency of Mo/Mφ TLR4 signaling alters induction of fibrinolytic/matrix remodeling gene expression. Ex vivo TLR4 agonism increased whole blood thrombolysis in Cre- but not Cre+ mice. Additional TLR2 agonism of Cre+ mice restored thrombolytic activity, suggesting TLR2 as a compensatory pathway that may account for the unchanged in vivo phenotype in LysMcreTlr4fl/fl mice. Further clarifying these cellular pathways may provide an alternate pathway to target VT resolution.

Effects of CDT on Hemodynamics and Quality of Life in a Subgroup of Patients with Lower Limb Deep Vein Thrombosis Carel: A Case-Control Study.

Objective To explore the effects of combined catheter-directed thrombolysis (CDT) on hemodynamics and quality of life in a subgroup of patients with lower limb deep vein thrombosis carel by using a case-control study. Methods Eighty-four patients with deep venous thrombosis (DVT: acute DVT and chronic DVT) of lower extremities treated in our hospital from April 2017 to June 2021 were randomly assigned into the control group (n = 42) and the research group (n = 42). The control group only received routine nursing combined with CDT; the research group was treated with cluster nursing l combined with CDT. The clinical efficacy, the difference in limb circumference, hemorheology, hemodynamics, coagulation index and life quality before and after treatment, and the nursing satisfaction scores were calculated. The effects of cluster nursing l combined with CDT on hemodynamics and life quality in patients with DVT of lower extremities were analyzed. Results The clinical curative effect of the research group was better than that of the control group (P < 0.05). After intervention, the difference in the thigh and leg perimeter in the research group was reduced, and the difference in the thigh and leg perimeter in the research group was significantly lower than that in the control group (P < 0.05). After intervention, the whole blood low shear viscosity, plasma viscosity, platelet aggregation rate, and fibrinogen in the research group were lower than those in the control group (P < 0.05). After intervention, segmental venous volume (SVC), maximum venous blood flow (MVO), and SVC/MVO in the research group were significantly higher than those before intervention, VRT was significantly prolonged, and MVO and venous pressure recovery time (VRT) were significantly higher than those in the control group. After intervention, D-dimer and fibrinogen decreased, prothrombin time and activated partial thromboplastin time increased in the research group, and the improvement of blood coagulation index in the research group was significantly better than that in the control group (P < 0.05). After intervention, the scores of quality of life in the research group decreased, and the scores of physiological function, psychological function, social function, and health self-cognition in the research group were lower than those in the control group (P < 0.05). The satisfaction of patients in the research group was significantly higher than that in the control group (P < 0.05). Conclusion The application of cluster nursing l combined with CDT can effectively prevent lower limb venous thrombosis after operation and can enhance patients' hemorheology, hemodynamics, and blood coagulation function and significantly promote their life quality, nursing satisfaction is high, and it is worth popularizing and applying in clinic.

Warfarin versus direct oral anticoagulants for patients needing distal deep vein thrombosis treatment

ObjectiveGreat interest exists in standardizing the anticoagulant choice for patients requiring treatment of distal deep vein thrombosis (DDVT). In the present multicenter, retrospective cohort study, we evaluated the outcomes of patients with DDVT who had been treated with warfarin vs direct oral anticoagulants (DOACs; ie, rivaroxaban, apixaban, edoxaban, dabigatran). MethodsQueries were built for the TriNetX database (TriNetX LLC, Cambridge, Mass), a federated network of healthcare organizations across the United States that provides de-identified patient data through aggregated counts and statistical summaries. International Classification of Diseases, 10th revision, diagnostic codes were used to identify eligible patients. Data from January 1, 2013 to January 1, 2020 were reviewed. Statistical analyses, including propensity matching, were performed using TriNetX’s internal software. The inclusion criterion was treatment with either warfarin or a DOAC started within the first 24 hours of diagnosis of an isolated thrombosis of the following veins: anterior tibial, posterior tibial, peroneal, or calf muscular veins. The exclusion criteria were a history of an adverse reaction to anticoagulant agents, SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection, thrombophilia, mechanical heart valve, chronic proximal DVT (PDVT) and/or DDVT, and 6-month history of the following: acute PDVT, pulmonary embolism (PE), or anticoagulant usage. The outcomes measured included the incidence of mortality, PE, PDVT, stroke, myocardial infarction, and major bleeding within 6 months after initiating anticoagulation therapy. ResultsIn a cohort of 6509 patients, 1570 were treated with warfarin and 4939 were treated with a DOAC drug. After propensity matching for age, sex, ethnicity, and comorbidities, the DOAC cohort had a significantly lower incidence of PE (1.795% vs 3.590%; P = .0020) and major bleeding (7.949% vs 10.513%; P = .0134). Differences in the incidence of mortality, PDVT, myocardial infarction, and stroke were not statistically significant. ConclusionsBefore the present study, no strong evidence was available to suggest an optimal treatment modality for DDVT requiring anticoagulation therapy. The data from the present study suggest that patients receiving DOACs for the treatment of DDVT will have significantly lower rates of progression to PE and a lower incidence of major bleeding compared with patients receiving warfarin. This suggests that DOACs are superior to warfarin for treatment of DDVT.

Mortality and Associated Comorbidities Among Patients Hospitalized for Deep Vein Thrombosis and Pulmonary Embolism in the United States: Results from a Nationally Representative Database

Introduction Venous thromboembolism (VTE) (deep vein thrombosis [DVT] and pulmonary embolism [PE]) is a cause of significant morbidity and mortality. Over the last decade, there has been an increase in awareness and major advances in early diagnosis and treatment of VTE. This study sought to estimate the mortality and associated diagnoses in hospitalized patients with a primary diagnosis of DVT or PE using a nationally representative database. Methods The 2017 Healthcare Cost and Utilization Project's Nationwide Inpatient Sample (HCUP-NIS) was used for analysis. The NIS uses a stratified probability sample of 20% of all inpatient discharges, representing over 97% of the US population. Sampling weights were applied to hospital discharges for DVT and PE using applicable ICD-10 codes to generate nationally representative estimates. Pearson's chi-squared test and the Mann-Whitney U test were used for comparisons to assess statistical significance. Results Of the nearly 36 million hospital admissions in 2017, 579,860 had DVT included in the index list of diagnoses during the hospitalization, and 105,635 had DVT as the primary admission diagnosis. Within the primary DVT admissions (median age (interquartile range (IQR)): 64 years (51-77)), 102,505 were acute DVT, and 3,130 were chronic DVT. There were 376,140 admissions with PE as one of all diagnoses and 188,245 with PE as the primary admission diagnosis. Among primary PE admissions (median age (IQR): 64 years (52-75)), 16,205 (8.6%) were saddle PE (Figure 1a). Overall, there were 826,155 people diagnosed with PE or DVT as one of any diagnoses, and 129,845 were diagnosed with both DVT and PE. Mortality The all-cause mortality in admissions with a primary diagnosis of DVT (0.8%) was significantly lower than for all other NIS admissions at 1.96% (p&amp;lt;0.001) (Figure 1a). Among primary DVT admissions who had in-hospital mortality, the median age (IQR) at death was 72 years (61-82), which was comparable to 73 years (61-83) for all other NIS hospitalizations. The median (IQR) length of stay (LOS) of primary DVT admissions who had in-hospital mortality was 5 days (3-10). For primary PE admissions, the all-cause mortality (3.0%) was significantly higher than all other NIS admissions (p&amp;lt;0.001). Among the PE admissions, mortality in those with saddle PE (4.2%) was significantly higher than all other PE cases (p&amp;lt;0.001) (Figure 1b). The median (IQR) age at death for PE patients was 71 years (60-81) and was comparable to all other NIS hospitalizations. The median (IQR) LOS for deaths in PE admissions was 3 days (1-7). Besides the known cardiovascular disease risk factors such as hypertension, obesity, smoking, Type 2 diabetes mellitus, and hyperlipidemia, the most common diagnoses in those who died with DVT or PE as a primary diagnosis were acute kidney failure, cancer, and chronic kidney disease (CKD) (Table 1). Health Care Utilization The median (IQR) hospital charges for DVT and PE admissions were $27,476 ($15,053-$54,874) and $29,158 ($17,471-$52,636) respectively. These were comparable to all NIS hospitalizations at $26,841 ($12,969-$54,568). For hospitalizations for DVT and PE resulting in death, the median (IQR) hospital charges were $60,689 ($24,775-$137,830), and $55,218.50 ($29,373-$106,313) respectively which were comparable to all NIS deaths at $56,107 ($23,117-$131,768). Discussion/Conclusions In the United States, DVT or PE was listed as one of the discharge diagnoses in approximately 825,000 admissions in 2017 and was the primary reason for admission in 300,000 cases (0.8% of all admissions). PE was seen more often as a primary cause for hospitalization, while DVT was more often seen as a comorbidity. The all-cause mortality among admissions for PE was greater than that for DVT. The subset of PE patients with saddle embolism had the highest mortality rate of all admissions for VTE. Besides cardiovascular risk factors, cancer, acute kidney failure, and CKD were among the most common comorbidities seen in admissions with PE and DVT that had in-hospital mortality. Disclosures Streiff: Bayer: Consultancy, Speakers Bureau; Portola: Consultancy; Boehringer-Ingelheim: Research Funding; NHLBI: Research Funding; PCORI: Research Funding; NovoNordisk: Research Funding; Sanofi: Research Funding; Dispersol: Consultancy; BristolMyersSquibb: Consultancy; Janssen: Consultancy, Research Funding; Pfizer: Consultancy, Speakers Bureau. Takemoto:Novartis: Other: DSMB Aplastic Anemia Trial; Genentech: Membership on an entity's Board of Directors or advisory committees.

Wasp sting complicated with chronic DVT and pulmonary artery thromboembolism: a rare case report

Pulmonary embolism remains a disease that needs high clinical suspicion to prevent mortality and morbidity. More so in young healthy individuals, the suspicion is very low as compared to old age individuals with multiple co-morbid conditions. Pulmonary embolism carries high mortality if not suspected and treatment initiated as early as possible. Authors describe a case of yellow wasp stings associated with chronic left leg DVT and pulmonary artery thrombosis, which is rare following wasp stings and therefore extend the clinical spectrum of wasp envenomation.

SONOGRAPHIC INCIDENCE AND EXTENT OF LOWER LIMB DEEP VENOUS THROMBOSIS IN HOSPTILISED PATEINTS OF TERTIARY CARE HOSPITAL

Purpose: The aim of our study was to determine the incidence and extent of deep venous thrombosis in hospitalized patient of tertiary care hospital.Methodology: This was observational cross sectional study. The data of patients had been collected from Jinnah hospital Lahore, Pakistan. After taking informed consent, data was collected through the Doppler ultrasound which was performed for lower limb in symptomatic patients. Equipment used was TOSHIBA Xario (200) with linear probe frequency ranging from 7-10 MHz. The data analysis was performed with the help of SPSS version 24.Findings: Total 124 patients were included in this study in which the mean age of the patient was 45.38 ± 16.846 with a range of 14-90 years. The Mean weight of patients was = 70.31±9.285 with the range 48­-90kg. The females were 56 and males were 68 in number included in this study. Out of 124 patients, right leg DVT present in 44(35.5%), and left leg DVT present in 74(59.7%), and bilateral DVT present in 6(4.8%) of patients. Unique contribution to theory, practice and policy: It was concluded that age plays a significant role in the development of DVT. Patients with acute DVT have hypoechoic thrombus while the chronic DVT have hyperechoic echogenicity. DVT was most commonly seen in the left leg in comparison with right leg. Ultrasound is the best modality in the detection of DVT.

The Missing Inferior Vena Cava with Acute on Chronic Undiagnosed DVT’S

The Missing Inferior Vena Cava with Acute on Chronic Undiagnosed DVT’S

Technical success and short-term outcomes after treatment of lower extremity deep vein thrombosis with the ClotTriever system: A preliminary experience

BackgroundDeep vein thrombosis (DVT) may be associated with significant pain, swelling and the development of post-thrombotic syndrome. Early clot removal is facilitated by the use of percutaneous mechanical thrombectomy devices. Current techniques, however, vary in rates of technical success and in some cases are limited by the concomitant need for thrombolytics. An alternative percutaneous venous thrombectomy system (ClotTriever, Inari Medical, Irvine, Calif) may be helpful in the management of lower extremity DVT without the concomitant use of thrombolytics. MethodsA retrospective review of patients treated for DVT using the device was conducted. Demographics, initial presentation, and perioperative course were recorded. Outcomes after treatment were extracted from clinical records. Technical success was defined as complete clot evacuation after intervention. ResultsTwelve patients were included in the study. The cohort was 50% female (6 patients) with a mean age of 55.6 years (range, 32-86 years). Two patients (16.7%) presented with chronic asymptomatic DVT who developed symptoms from an acute, recurrent iliofemoral DVT over the days before presentation. One patient (8.4%) presented with phlegmasia cerulea dolens, with the remaining patients presenting with disabling pain and swelling. Access was obtained via the popliteal vein (11 patients) and small saphenous vein (1 patient). Lytic therapy was not used in any case. Complete clot evacuation was obtained in all patients in a single session without repeat interventions. Symptom resolution before discharge was achieved in 100% of cases. There was no incidence of postoperative anemia (mean hemoglobin, 10.7 g/dL preoperatively vs 10.4 g/dL postoperatively) or acute kidney failure (mean creatinine, 0.86 mg/dL preoperatively vs 0.81 mg/dL postoperatively). The average length of stay was 2 days (range, 1-4 days) without the need for intensive care admission. At early follow-up, 11 patients (91.7%) continued to report significant symptom resolution. Two of 10 patients (20%) developed recurrent occlusive DVTs on follow-up duplex ultrasound examination. ConclusionsThis novel percutaneous venous thrombectomy system is safe and effective for removing large volumes of lower extremity acute thrombus in a single session, without the need for lytic therapy, intensive care unit admission, or repeat intervention. Further studies are warranted to determine mid-term and long-term outcomes.

High Prevalence and Mortality Associated with Upper Extremity Deep Venous Thrombosis in Hospitalized Patients at a Tertiary Care Center

Upper extremity deep venous thrombosis (UEDVT) and its associated complications are increasing in incidence, but management strategies are largely derived from experience treating lower extremity deep venous thrombosis (LEDVT). The purpose of this study is to examine our single institution's experience with in-hospital venous thromboembolism (VTE), specifically the characteristics and outcomes of the UEDVT population as it compares to LEDVT. This is a single tertiary care center retrospective cohort study of all consecutive inpatients diagnosed with acute VTE from June 2015 to December 2015. During this period, 4,495 patients underwent venous duplex examination (622 UE and 3,873 LE), identifying 83 inpatient DVTs. Chronic DVT and those diagnosed in the outpatient population were excluded. DVTs were classified as either provoked or unprovoked. Provoked DVT were defined as the presence of any of the following factors within 30days prior to diagnosis: major surgery, immobilization (greater than 3days of bedrest), trauma, infection requiring antibiotics, central venous access, pregnancy, and/or hormonal medication use. Inpatient pulmonary embolisms (PE) detected on chest computed tomography (CT) were also evaluated during this time frame. Patient data were collected, including age, gender, race, lifestyle factors, comorbidities, VTE risk factors, symptomatology at presentation, management including anticoagulation choice and filter placement if applicable, as well as discharge disposition. Statistical analysis was performed using GraphPad Prism 8.0 (GraphPad Software, San Diego, California), and a threshold P-value of <0.05 set for significance. During the study period, 83 DVTs (48 LEDVT, 35 UEDVT) and 24 PE were identified in 96 inpatients. Of these DVTs, 77.1% of these were defined as provoked. Eleven patients had simultaneous DVT and PE, and thirteen patients had PE with presumed occult pelvic or LEDVT. UEDVT patients had a higher proportion of comorbidities than LEDVT patients: coronary artery disease (25.7% vs. 13.1%, P=0.16), congestive heart failure (20% vs. 6.6%, P=0.09), as well as a trend toward higher incidence of malignancy (60% vs. 42.6%, P=0.13). Of provoked VTE, UEDVT correlated more significantly with central venous catheters (88.4% vs. 12.5%, P=<0.0001), but was less commonly associated with prolonged bed rest (19.2% vs. 39.5%, P=0.11). PE was diagnosed in 24/96 (25%) of the study population. Patients with LEDVT were found to have a significantly higher incidence of PE compared to those with UEDVT (34.4% vs. 8.6%, P=0.006). Same-admission mortality for patients with VTE was 13/96 (13.5%). Of these, patients with UEDVT had significantly higher all-cause mortality than patients with LEDVT (28.5% vs. 4.9%, P=0.004). When catheter-related UEDVT was excluded, there remained a significant difference in mortality between non-catheter-related UEDVT and LEDVT (33.3% vs. 4.9% P=0.0119). This study demonstrates a high prevalence of UEDVT in hospitalized patients who experience VTE. Despite a lower incidence of synchronous PE, patients with UEDVT had a higher prevalence of significant medical comorbidities and higher all-cause mortality on the index hospital admission.

Posterior tibial vein approach to catheter-directed thrombolysis for iliofemoral deep venous thrombosis

ObjectiveDeep venous thrombosis (DVT) remains a significant cause of morbidity in the American population. Catheter-directed thrombolysis for acute iliofemoral DVT is an effective therapy not only to restore venous patency but also to reduce the development of post-thrombotic syndrome (PTS), especially in patients with extensive thrombosis involving the iliac and femoral venous segments. We hypothesized that delivery of thrombolytics through an access site in a vein distal to the segments containing thrombus would provide the greatest short- and long-term therapeutic clinical benefit with similar safety and efficacy. MethodsAll patients treated at a single institution between 2009 and 2016 undergoing mechanical and chemical thrombolysis for iliofemoral DVT were retrospectively reviewed. Patients were divided into groups by access site, including contralateral and ipsilateral femoral vein, popliteal vein, and posterior tibial vein (PTV). Preoperative demographics, intraoperative data, and postoperative outpatient charts were analyzed. Primary end points included evidence of incompetence after the procedure by duplex ultrasound assessment and development of complications of PTS as defined by the Villalta scale. ResultsFifty-eight patients underwent mechanical and chemical thrombolysis, and 51 patients met the inclusion criteria. Thrombolysis access was through PTV (n = 27), popliteal vein (n = 20), or femoral vein (n = 4). More patients were female (55%), and the mean age was 57 years. Forty patients had unilateral DVT, whereas 11 patients had bilateral involvement. After lysis, 44 patients underwent percutaneous venous angioplasty and 11 patients underwent venous stenting in the acute setting. Although not statistically significant, mean operative times were slightly longer in the posterior tibial approach (156.7 minutes vs 130.6 minutes; P = .08), and mean fluoroscopy time was higher in the posterior tibial group (18.1 minutes vs 14.3 minutes; P = .17). Overall 90-day morbidity was 9.8%, and no deaths were recorded. Patency of the deep venous system was similar between the posterior tibial and the popliteal or femoral approach (95% vs 88%; P = .29); 21.6% developed symptoms of PTS. There was no difference for development of PTS between posterior tibial and popliteal or femoral approaches (22% vs 20.8%; P = .52). There was no difference in development of chronic nonocclusive DVT (37% vs 35%; P = .61). Median follow-up was 8.7 months (range, 0.4-58.9 months). ConclusionsThe PTV approach to catheter-directed thrombolysis is a safe and sensible option for the treatment of iliofemoral and femoropopliteal DVT. A larger cohort will be necessary to demonstrate superiority of tibial vein access in the treatment of iliofemoral DVT with popliteal involvement.

Iliac vein compression: epidemiology, diagnosis and treatment.

Iliac vein compression (LIVC) is a prevalent finding in the general population, but a smaller number of patients are symptomatic. ILVC should be considered in symptomatic patients with unexplained unilateral lower leg swelling. Patients typically complain of one or more of the following symptoms: lower leg pain, heaviness, venous claudication, swelling, hyperpigmentation and ulceration. ILVC can be thrombotic, combined with acute or chronic DVT, or non-thrombotic. ILVC is best diagnosed with intravascular ultrasound (IVUS), but computed tomography angiography (CTA) and magnetic resonance angiography (MRA) have emerged as valid screening tests. Venography underestimates the severity of ILVC but may provide insights into the anatomy and the presence of collaterals. Based on current available evidence, endovascular therapy with stenting remains the main treatment strategy for ILVC. Dedicated nitinol venous stents are currently under review by the Food and Drug Administration for potential approval in the United States. These stents have been released outside the US. There is no consensus to the optimal anticoagulation regimen post-ILVC stenting. Oral anticoagulants, however, remain a preferred therapy in patients with history of thrombotic ILVC.

Assessment of deep venous thrombosis in the lower extremity in Behçet's syndrome: MR venography versus Doppler ultrasonography.

Lower extremity venous thrombosis (DVT) is the most common vascular manifestation of Behçet's syndrome (BS). Currently, Doppler ultrasonography (USG) is the most commonly preferred imaging modality in the diagnosis and follow-up of patients with acute and chronic DVT. Magnetic resonance (MR) venography, a quick and a non-invasive imaging modality, is successfully used to detect DVT in various settings. We had been unaware of studies with MR venography in BS. The aim of this study is to compare the diagnostic value of true fast imaging with steady-state precession magnetic resonance (True-FISP MR) venography and Doppler USG in the assessment of chronic DVT among patients with BS. 28 BS patients with chronic lower extremity DVT were studied. Common femoral (CFV) and femoral vein (FV) on both right and left sides were examined for the presence of thrombosis, recanalisation, collaterals and reflux. There are findings of chronic DVT in all Doppler USG images of 28 patients (45 of 56 FV and 35 of 56 CFV), while MR venography detects chronic thrombotic changes in 26/28 (93%) patients (43 of 52 FV and 28 of 52 CFV). Collateral veins are detected in 19 patients (19/28) with MR venography, whereas they are present in only 7 (7/28) with USG (P = 0.003). Furthermore, patients with severe post-thrombotic syndrome are more likely to have collateral formation on the MR compared to those without (12/14 vs 7/14; P = 0.043). Among patients with BS, MR venography might be an alternative or additional method to detect chronic thrombosis in the lower extremities.

Risk Factors and Outcomes of Deep Vein Thrombosis in Pediatric Osteomyelitis

Background:Estimates of the incidence of DVT in patients with osteomyelitis range widely from 5%-30%, however risk factors and outcomes of DVT in this cohort have not been thoroughly established.Objective:This study aims to estimate the incidence of DVT in patients with osteomyelitis, and to assess risk factors and outcomes of DVT.Design/Method:After IRB approval, a retrospective chart review was conducted for patients aged 0-18 years seen at Phoenix Children's Hospital between 2012-2016 with ICD 9/10 codes for osteomyelitis. Exclusion criteria included chronic recurrent multifocal osteomyelitis, and chronic DVT. Demographics, clinical factors and outcomes were compared between osteomyelitis patients with and without DVT using the Fisher-exact and Wilcoxon-rank sum tests, as appropriate for the data distribution.Results:A total of 179 study subjects with osteomyelitis had a mean (standard deviation) age of 8.4 (5.7) years. DVT was present in 14 (8% of 179) patients, and 4 (28%), 5 (36%) and 5 (36%) patients received anticoagulation for < 6, 6-12 and ≥12 weeks, respectively. Patients with vs without DVT were more likely to be male (86% vs 59%; p-value=0.05), and had significantly higher rates of bacteremia (64% vs 24%; p-value=0.003). Rates of central lines were comparable between DVT and non-DVT patients (71% vs 68%; p-value=1.00); however patients with DVT vs without DVT had significantly longer mean length of stay (18 vs 9 days; p-value <0.0001) and higher rates of ICU admission (71% vs 16%; p-value <0.0001).Conclusion:The incidence of DVT among osteomyelitis pediatric patients was estimated at 8%, with risk increased by male sex and bacteremia. Patients with DVT had significantly higher rates of ICU admission and longer length of hospital stay. Many of these patients had standard practice management of their DVT with 6-12 weeks of anticoagulation underscoring the need for future efforts targeting DVT prophylaxis. DisclosuresNo relevant conflicts of interest to declare.

3:18 PM Abstract No. 353 Nitinol self-expanding stents for the treatment of chronic iliofemoral veno-occlusive disease

To evaluate the clinical and technical outcomes of nitinol self-expanding stents for the treatment of symptomatic chronic iliofemoral veno-occlusive disease. A retrospective review was performed of 169 consecutive patients (196 limbs) treated with self-expanding nitinol stents for chronic iliofemoral veno-occlusive disease between July 2011 and June 2017. Patients treated with non-nitinol stents and patients with IVC involvement were excluded. Procedural and follow-up data were collected for assessment of technical success, clinical outcomes, safety, and patency. Technical success was defined as the ability to recanalize and stent the obstructive lesion without significant residual stenosis. Binary patency was assessed with duplex ultrasound and calculated by Kaplan Meier analysis. Clinical outcomes were evaluated utilizing CEAP and Villalta scores. A total of 378 (278 Left, 95 Right) nitinol self-expanding stents were placed with sizes ranging from 8 to 14 mm. Technical success was achieved in 195 of 196 limbs (99%). Of the 169 patients, 100, 45, and 24 presented with symptoms consistent with acute, acute on chronic, and chronic DVT, respectively. Mechanical thrombectomy was performed in 96 (49%) patients while catheter-directed thrombolysis was employed in 92 (47%) patients. Mean followup time was 9.8 months. Kaplan Meier analysis revealed a primary patency of 95%, 93%, 91%, and 91% at 6, 12, 24, and 36 months respectively. Pre- and post-CEAP or Villalta scores were available in 140 (83%) patients. CEAP and Villalta scores improved from 3.65 to 2 (-55%) and 19.15 to 8.6 (-45%), respectively. There were 5 recorded adverse events; 3 mild, 1 moderate, and 1 severe. Endovascular management of chronic iliofemoral veno-occlusive disease with self-expanding nitinol stents is a safe and durable procedure with high technical success, excellent mid-term patency, and good clinical outcomes.

Iliac Vein Stenting Following Catheter Directed Thrombolysis for Acute Iliofemoral Thrombosis: Outcomes and Predictors of Failure

Iliac vein stenting is recommended to treat venous outflow obstruction following catheter directed thrombolysis for acute iliofemoral thrombosis (IFDVT). Data on the outcome of proximal and distal stent extension is limited. Proximal stent extension to the vena cava may obstruct the contralateral iliac vein, while distal extension below the inguinal ligament contradicts common practice for arterial stents. The aim of the study was to assess outcomes and predictors of failure of iliac vein stents and contralateral iliac vein thrombosis taking into consideration stent positioning. Consecutive patients that underwent thrombolysis and stenting for IFDVT between May 2007 and September 2017 were identified from a prospectively maintained database. The intraoperative venograms were reviewed for proximal stent placement (covering >50%contralateral iliac vein orifice) and distal placement across the inguinal ligament. End points were ipsilateral DVT recurrence, post-thrombotic syndrome (Villalta score ≥5) and contralateral IFDVT. Patients with chronic contralateral DVT, or contralateral iliac vein stenting at baseline were excluded from the “contralateral IFDVT” outcome evaluation. Survival analysis and Cox regression models were used to determine outcomes. Out of 142 patients lysed, 73 patients (12 bilateral IFDVTs, mean age 45.8 ± 17.2 years, 46 females) were treated with various combinations of thrombolytic techniques and at least one self-expanding iliac stent (77 stented limbs). Thirty-day recurrence occurred in nine (12.3%) patients. The 3-year primary and secondary patencies were 75.2% and 85.2% respectively. The single predictor for loss of primary patency was incomplete thrombolysis (≤ 50%; hazard ratio [HR], 7.41; P = .002). Overall, 3/12 stents extending below the inguinal ligament failed at 1, 2 and 9 months respectively. The overall rate of PTS (Villalta score ≥5) in the stented cohort was 14.4% at 5 years. This was predicted by incomplete lysis (<50%) (HR, 7.09; P = .040), stenting below the inguinal ligament (HR, 6.68; P = .026) and male gender (HR = 6.02; P = .041). Out of 17 stents covering the contralateral common iliac vein and 58 stents not covering it, there were 1 (5.9%) and 5 (8.6%) contralateral DVTs (P = .588) at an average follow-up of 27.4 ± 33.7 and 22.2 ± 22.3 months (P = .552) respectively. Iliac stenting following thrombolysis for acute IFDVT guarantees high success rates provided that adequate thrombus resolution has been achieved prior to stent placement. Stent placement below the inguinal ligament does not affect the patency but may be associated to a higher PTS rate. Stenting proximal to the iliocaval confluence may not independently increase the likelihood of contralateral DVT.

The role of vacuum assisted thrombectomy (AngioVac) in treating chronic venous thromboembolic disease. Systematic review and a single center's experience.

Beyond medical therapy, the role of endovascular approach for the management of chronic Venous Thromboembolic (VTE) disease is yet to be defined. To our knowledge, no systematic reviews or guidelines are available that provide information on how to manage this chronic condition. This paper represents the first systematic review of published reports on the use of vacuum-assisted thrombectomy (AngioVac) in treating chronic VTE disease. A systematic review of published case-series, individual case-reports, and review articles in MEDLINE, PubMed, and Google Scholar was conducted. Keywords used for the search were: "vacuum assisted thrombectomy", "AngioVac", "thrombectomy", and "chronic venous thrombosis". Inclusion criteria were a diagnosis of chronic DVT (>28 days) and the use of vacuum-assisted thrombectomy device (AngioVac) with or without additional endovascular therapy. Our selection process followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. The literature search was conducted through June 2017. The initial search yielded 51 publications of which 18 reported the use of vacuum assisted thrombectomy (AngioVac) in treatment of venous thrombosis but only 7 reports (13 patients) met our inclusion criteria. Similarly, 5 patients representing our center's experience were included in the analysis. Patients' demographics, admission diagnoses, risk factors, and procedural success were individually reported. Procedural success (both partial and complete resolution of thrombus burden) was achieved in 15 of the 18 cases (83%). Failure to re-canalize or significantly improve venous flow was seen in only 3 cases. No procedural mortality was reported. However, in-hospital and long-term mortality rates were not reported. Vacuum-assisted thrombectomy using the AngioVac system is a minimally invasive alternative to surgical thrombectomy for chronic VTE management. The use of this device in iliocaval thrombosis appears to be safe and effective compared to other anatomical locations. Further outcome studies are needed to define long-term benefits of mechanical thrombectomy in treating chronic VTE diseases.

Prevalence of lower limb deep venous thrombosis among adult HIV positive patients attending an outpatient clinic at Mulago Hospital

BackgroundDeep venous thrombosis (DVT) and its major complication pulmonary embolism (PE) are collectively known as venous thromboembolism. In Uganda, the prevalence of DVT among HIV patients has not been previously published. The aim of the study was to determine the prevalence and sonographic features of lower limb deep venous thrombosis among HIV positive patients on anti-retroviral treatment (ART).MethodsThis was a cross sectional study in which HIV positive patients on ART were recruited from an out-patient HIV clinic at Mulago National Referral Hospital. Patients were randomly selected and enrolled until a sample size of 384 was reached. Study participants underwent compression and Doppler ultrasound studies of both lower limb deep veins using Medison Sonoacer7 ultrasound machine.ResutsWe found a prevalence of DVT of 9.1% (35 of 384 participants) among HIV patients on ART. The prevalence of latent (asymptomatic) DVT was 2.3%. Among 35 patients with DVT, 42.8% had chronic DVT; 31.1% had acute DVT and the rest had latent DVT. Among the risk factors, the odds of occurrence of DVT among patients with prolonged immobility were 4.81 times as high as in those with no prolonged immobility (p = 0.023; OR = 4.81; 95% CI 1.25–18.62). Treatment with second line anti-retroviral therapy (ART) including protease inhibitors (PIs) was associated with higher odds of DVT occurrence compared with first line ART (p = 0.020; OR = 2.38; 95% CI 1.14–4.97). The odds of DVT occurrence in patients with a lower CD4 count (< 200 cells/µl) were 5.36 times as high as in patients with CD4 counts above 500 cells/µl (p = 0.008). About 48.6% patients with DVT had a low risk according to Well’s score.ConclusionDVT was shown in nearly 10% of HIV patients attending an out-patient clinic in an urban setting in Uganda. Risk factors included protease inhibitors in their ART regimen, prolonged immobility, and low CD4 count (< 200 cells/µl). Clinicians should have a low threshold for performing lower limb Doppler ultrasound scan examination on infected HIV patients on ART who are symptomatic for DVT. Therefore, clinicians should consider anti-coagulant prophylaxis and lower deep venous ultrasound screening of patients who are on second line ART regimen with low CD4 cell counts and/or with prolonged immobility or hormonal contraception.

An Electrical Thrombectomy Device Using Plasma Created Chemistry in a Saline Environment to Dissolve Vascular Clots

An electrical thrombectomy device, using liquid plasma generated radicals for removing intravascular blood clots, causing either the chronic total occlusion clots or DVT clots, was demonstrated. We employed a proxy experimental clot model of DVT with the blood filled collagen sheets. We also treated a real equine blood clot. Both clot samples were provided by the Veterinary Hospital of Colorado State University. Optical emission spectroscopy was used to examine the relative populations of the reactive chemical species generated by the liquid plasma that drives the clot dissolution during 10 min. of liquid plasma treatment at 20 W of average input power. The removal rate of the blood clots is typically up to 2 mm3 per minute and cylindrical volumes of 3 mm diameter and 14 mm long were removed. The thermal damage to contiguous tissue at the periphery of the removal volume was determined to be is >200 µm from conventional histology analysis. We determined by FTIR spectroscopy that the collagen denaturing in liquid plasma occurs primarily via Amide III bond breakage.

Endovascular Treatment of Veno-Occlusive Behcet’s Disease

To retrospectively evaluate the outcome of endovascular treatments for patients with chronic veno-occlusive disease in different vascular beds secondary to Behcet's disease (BD). There are few case reports on the subject, and this is the largest study to date. From January 2001 through October 2009, chronic venous occlusions were treated in 10 patients (all male [age range 18-76 years]) with BD using percutaneous transluminal angioplasty and/or stent placement. All patients were symptomatic and had chronic iliofemoral deep venous thrombosis (DVT; n = 5), central venous occlusion (n = 3), or Budd-Chiari syndrome (BCS; n = 2). All patients met criteria of the International Study Group on Behcet's Disease. Two of five patients with DVT had unsuccessful recanalization attempts. Three patients had successful recanalization with stent placement. All three veins were occluded within 1 month with unsuccessful reinterventions. Three patients with chronic central venous occlusion had successful recanalization with percutaneous transluminal angioplasty (n = 1) and stent placement (n = 2). Two patients had reocclusion with successful reintervention. Two BCS patients had successful treatment with stent placements. Overall technical success was 69%, and no procedural complications were encountered. None of the patients with chronic DVT had patent veins; however, all patients with central venous occlusion or BCS had patent veins on color Doppler ultrasonography at follow-up ranging from 3 to 48 months after intervention. Endovenous treatment for chronic iliofemoral DVT due to BD had a poor outcome. However, long-term outcome after endovenous treatment for upper-extremity central venous occlusion and BCS syndrome was good.

A Rare Vascular Tumor Presenting as Persistent Pain at the Site of a Chronic DVT

A Rare Vascular Tumor Presenting as Persistent Pain at the Site of a Chronic DVT