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Background: Implantation of a retrievable vena cava filter (VCF) is an effective method for preventing pulmonary embolism. Retrieval of filters, however, may be difficult due to intimal hyperplasia and inflammation in the cava wall. The transcription factor nuclear factor-kappaB (NF-κB) plays an important role in regulation of numerous genes participating in the inflammatory and proliferative responses of cells. The present study was to determine whether VCF implantation resulted in activation of NF-κB in the venous neointima., Methods: Filters were placed in vena cava (VC) in four swine for 30 days and then removed. Intimal specimens adhering to the filter struts were analyzed with reference to normal VC tissues. Immunohistochemical analyses were used to assess the NF-κB subunits p65 and p50 and the phosphorylated inhibitor of κB-α (phosphor-IκB-α) in the tissues. NF-κB DNA-binding activity was measured with enzyme-linked immunosorbent assay., Results: As compared to normal VC tissues, the intimal tissues contained higher percentages of cell nucleus-located p65 and p50, and NF-κB DNA-binding activity. Elevated immunoreactivities of p65, p50 and phosphor-IκB-α were also present in the intima., Conclusion: The present study demonstrates for the first time that VCF implantation caused NF-κB activation in neointima. We further demonstrate the activation is at least partly due to phosphorylation of IκB-α. Our data suggest that NF-κB activation would significantly contribute to development of intimal hyperplasia and inflammation in filter-inserted vena cava walls. NF-κB might be a therapeutic target for inhibiting filter-induced neointima and improving filter retrieval.

Background: Therapeutic and prophylactic vena cava filters (VCFs) are used to prevent pulmonary embolism. Concerns exist over placing a permanent filter in a young trauma patient. Recently, retrievable VCFs have become available. One such filter is the OptEase, which has a recommended time of removal of up to 23 days after insertion. Data supporting this recommendation are sparse. Many trauma patients will need filters for more than 2 weeks, and there are no data evaluating the safety of removal after extended time periods. The purpose of this study was to determine the safety, feasibility, and reaction of the vena cava when removing the OptEase retrievable VCF at different time intervals., Methods: Twenty Yorkshire cross pigs (80-113 kg) underwent general anesthesia with tiletamine and zolazepam. Filters were placed in the infrarenal vena cava (VC) through the femoral vein under fluoroscopic guidance. Animals were then divided into four groups. In group 1, filters were removed at 14 days; in group 2, at 30 days; in group 3, at 60 days; and in group 4, at 90 days. Removal was attempted using a snare-and-sheath technique through the femoral vein. Animals with successful filter removal were allowed to recover; then, the animals underwent autopsy (gross and microscopic VC examination) 2 months later. Animals with unsuccessful filter removal underwent autopsy immediately after attempted removal. Venacavograms were taken at filter insertion, at removal, and before autopsy to evaluate any VC abnormalities., Results: Successful removal of the filter in all five pigs (100%) was reliably performed only in the 14-day group. In this group, the initial VC transverse diameter was 19.4 +/- 0.8 mm and was significantly reduced to 9.8 +/- 1.1 mm (p < 0.05) immediately after removal. Sixty days later, before autopsy, VC diameter had increased to 15.3 +/- 1.9 mm, which was significantly larger than at removal (p < 0.05) but not different from the initial value. In the 30-day group, removal was successful in only one of five animals. Although removal was successful in the one pig, autopsy at 2 months postremoval revealed total occlusion of the VC. Filters could not be removed from 60- and 90-day groups. At autopsy, the VCF struts were embedded or protruded through the VC wall. Microscopic examination of the VC revealed significant scarring underneath and between the struts., Conclusion: Removal of the retrievable OptEase VCF may be successfully performed up to 14 days after insertion. Strut protrusion through the VC wall prohibited successful and safe removal at extended time intervals.

Background: Historically, contrast venography has been used to determine renal vein location and assist with vena cava filter placement. This technique, however, exposes the patient to nephrotoxic contrast and radiation. For trauma patients in the intensive care unit (ICU), inferior vena cava filters should ideally be placed without contrast at the bedside to avoid nephrotoxic agents, radiation, and transport of a critically injured patient to the operating room or x-ray department. Previously, the authors have shown that intravascular ultrasound is a safe and accurate method for locating renal veins and assisting with vena cava filter placement. The purpose of this study was to evaluate bedside vena cava filter placement prospectively using only intravascular ultrasound for imaging., Methods: Between August 2000 and July 2003, 29 patients met trauma service criteria for prophylactic or therapeutic placement of a vena cava filter. The 7 females and 22 males had a mean age of 51.3 years (range, 20-92 years), a mean height of 177 cm (range, 160-218.4 cm), a mean weight of 101.9 kg (range, 59.1-186.4 kg), and a body mass index of 33 (range, 14.7-56.1). Fifteen patients (55.5%) had a body mass index exceeding 30. The mean Injury Severity Score was 25.4 (range, 12-45). Intravascular ultrasound was the sole imaging method, and no contrast or fluoroscopy was used. All procedures were performed in the ICU by trauma surgeons. Data collection was prospective and included demographics, injuries, vena caval anatomy, length of procedure, complications, and follow-up radiographic confirmation of appropriate deployment., Results: The location of the renal veins and vena cava diameter was imaged in all the patients. Three patients were noted to have accessory renal veins, and no patient had thrombus in the vena cava. The inferior vena cava diameter was less than 28 mm in all the patients, thus allowing standard filters to be deployed. Filter deployment was successful for all the patients. Of the 29 patients, 27 had abdominal computed tomography (CT) during their hospital stay. When the location of the renal veins identified by CT was compared with the level of the filter on abdominal x-ray, the filter tip was found to be at or below the level of the most caudal renal vein in 26 of the 27 patients (96.3%). In one patient, the filter tip was purposely placed 2 to 3 cm above an accessory caudal renal vein, but below the main right and left renal veins. The mean procedure time was 37.7 minutes (range, 12-86 minutes). No complications were associated with filter placement., Conclusions: Intravascular ultrasound is a safe and effective imaging method that may be used for the bedside placement of vena cava filters in the ICU. This technique avoids the use of nephrotoxic intravenous contrast and eliminates the risk of transporting a critically injured patient to the operating room or x-ray department.

This study was designed to compare the incidence of venous thromboembolism (VTE) in Georgia trauma centers with other national trauma centers participating in the Trauma Quality Improvement Program (TQIP). The use of chemoprophylaxis and characteristics of patients who developed VTE were also examined. We conducted a retrospective observational study of 325,703 trauma admissions to 245 trauma centers from 2013 to 2014. Patient demographics, rate of VTE, as well as the use, type, and timing of chemoprophylaxis were compared between patients admitted to Georgia and non-Georgia trauma centers. The rate of VTE in Georgia trauma centers was 1.9 per cent compared with 2.1 per cent in other national trauma centers. Overall, 49.6 per cent of Georgia patients and 45.5 per cent of patients in other trauma centers had documented chemoprophylaxis. Low molecular weight heparin was the most commonly used medication. Most patients who developed VTE did so despite receiving prophylaxis. The rate of VTE despite prophylaxis was 3.2 per cent in Georgia and 3.1 per cent in non-Georgia trauma centers. Mortality associated with VTE was higher in Georgia trauma centers compared with national TQIP benchmarks. The incidence of VTE and use of chemoprophylaxis within Georgia trauma centers were similar to national TQIP data. Interestingly, most patients who developed VTE in both populations received VTE prophylaxis. Further research is needed to develop best-practice guidelines for prevention, early detection, and treatment in high-risk populations. [ABSTRACT FROM AUTHOR]