Gunther Tulip Filter Strut Penetration: Benign Long-Term Follow-up.

PURPOSE: To describe the natural history of Gunther Tulip filter (GTF) strut penetration based on the computed tomography (CT)-documented distance penetrated over time and any clinical manifestations. MATERIALS AND METHODS: The records of 203 patients (mean age, 59.1 years; 59.4% men) who had had an infrarenal GTF placed for venous thromboembolism (84.2%) with contraindications to anticoagulation (95.1%) and had CT follow-up were reviewed retrospectively for clinical or imaging evidence of complications. Filter strut penetration was measured on axial images from the outer caval wall to the inner edge of the distal end of each strut. Filter strut behavior over time was modeled using a linear mixed model. RESULTS: The extent of penetration correlated positively with filter dwell time (P < .001) but plateaued at 3.3 mm at 10-year follow-up. At median 4.7-year follow-up 79.3% of patients had at least 1 strut that was >0.2 mm and 31% had a strut >3 mm from the inferior vena caval wall. The extent of strut penetration was greater at all time points for women (P = .002). Abutment or entry into an adjacent structure was identified in 183 struts of 105 (52.7%) filters; of the 80 filters with CT follow-up, 47% showed progression and 19% regressed. There were no symptoms referable to filter strut penetration. CONCLUSIONS: GTF struts often penetrate the inferior vena cava progressively; however, this tends to plateau by 10 years. The limited long-term progression and a very low incidence of symptomatic complications together support a noninterventional approach to the finding of an asymptomatic GTF strut penetration.

Plasma DNA as a "liquid biopsy" incompletely complements tumor biopsy for identification of mutations in a case series of four patients with oligometastatic breast cancer.

PURPOSE: Circulating tumor DNA in plasma may present a minimally invasive opportunity to identify tumor-derived mutations to inform selection of targeted therapies for individual patients, particularly in cases of oligometastatic disease where biopsy of multiple tumors is impractical. To assess the utility of plasma DNA as a "liquid biopsy" for precision oncology, we tested whether sequencing of plasma DNA is a reliable surrogate for sequencing of tumor DNA to identify targetable genetic alterations. METHODS: Blood and biopsies of 1-3 tumors were obtained from 4 evaluable patients with advanced breast cancer. One patient provided samples from an additional 7 tumors post-mortem. DNA extracted from plasma, tumor tissues, and buffy coat of blood were used for probe-directed capture of all exons in 149 cancer-related genes and massively parallel sequencing. Somatic mutations in DNA from plasma and tumors were identified by comparison to buffy coat DNA. RESULTS: Sequencing of plasma DNA identified 27.94 ± 11.81% (mean ± SD) of mutations detected in a tumor(s) from the same patient; such mutations tended to be present at high allelic frequency. The majority of mutations found in plasma DNA were not found in tumor samples. Mutations were also found in plasma that matched clinically undetectable tumors found post-mortem. CONCLUSIONS: The incomplete overlap of genetic alteration profiles of plasma and tumors warrants caution in the sole reliance of plasma DNA to identify therapeutically targetable alterations in patients and indicates that analysis of plasma DNA complements, but does not replace, tumor DNA profiling. TRIAL REGISTRATION: Subjects were prospectively enrolled in trial NCT01836640 (registered April 22, 2013).

Short-interval recanalization after gelfoam occlusion.

Gelfoam® is a temporary embolization agent often used in trauma where permanent arterial occlusion is not desired. Gelfoam occlusions have been shown to resolve by 2 weeks, but shorter intervals have not been studied. We report a case of spontaneous arterial hemorrhage due to ruptured hepatic malignancy where treatment was Gelfoam slurry occlusion of the right hepatic artery. Repeat hemorrhage resulted in repeat CT and hepatic arteriography, which showed that recanalization of the occluded artery had occurred in less than 48 hours. Gelfoam arterial occlusion in some cases may last less than 2 weeks.

Roadmap guidance for the safer deployment of an arterial closure device.

Arterial closure devices reduce the time to hemostasis, ambulation, and discharge after percutaneous arterial catheterization, but there is an increased risk of arterial occlusive complications compared with manual compression. As a step toward the elimination of this risk, the authors describe a technique where the movement of a balloon-tipped vessel locator and its final position at the site of closure mechanism deployment are monitored with roadmap fluoroscopic imaging.

Activation of stem cell up-regulation/mobilization: a cardiovascular risk in both mice and humans with implications for liver disease, psoriasis and SLE.

Experimentally induced injury triggers up-regulation and mobilization of stem cells in Apoe -/- mice that causes accelerated atherosclerosis. Abca1 -/- Abcg1-/- mice have chronic activation of stem cell up-regulation/mobilization and accelerated atherosclerosis. In addition, the Abca1 -/- Abcg1-/- mice have elevation of serum cytokines G-CSF, IL-17 and IL-23, each necessary for stem cell mobilization. IL-17 and IL-23 are elevated in two human illnesses that have cardiovascular (CV) risk independent of traditional risk factors-SLE and psoriasis. Serum G-CSF, which can be elevated in liver disease, predicts major adverse cardiovascular events in humans. These serum cytokine elevations suggest activation of the stem cell mobilization mechanism in humans that results, as in mice, in accelerated atherosclerosis. Efforts to reduce CV disease in these patient populations should include mitigation of the diseases that trigger stem cell mobilization. Since activation of the stem cell up-regulation/mobilization mechanism appears to accelerate human atherosclerosis, use of stem cells as therapy for arterial occlusive disease should distinguish between direct administration of stem cells and activation of the stem cell up-regulation/mobilization mechanism.

Endovascular stent-graft or open surgical repair for blunt thoracic aortic trauma: systematic review.

PURPOSE: To evaluate the available data on stent-graft repair of acute blunt traumatic thoracic aortic injury with regard to safety and efficacy compared with conventional open surgical repair. MATERIALS AND METHODS: The literature on endovascular repair of acute traumatic aortic injury since 1990 was systematically reviewed. Metaanalysis of publications with open and stent-graft repair cohorts was performed to evaluate whether there was a difference in treatment effect with regard to mortality and paraplegia. Case series were included to obtain an adequate population to assess the incidence of stent-graft procedure-related complications. RESULTS: There were no prospective randomized studies. Nineteen publications that compared the outcomes of 262 endograft repairs and 376 open surgical repairs were identified. The odds ratio for mortality after endovascular versus open repair was 0.43 (95% CI, 0.26-0.70; P = .001). The odds ratio for paraplegia after endovascular versus open repair was 0.30 (95% CI, 0.12-0.76; P = .01). In the pooled group of 667 endovascular repair survivors from 50 reports, the incidence of early endoleak was 4.2%, and late endoleak occurred in 0.9%. Stroke or transient ischemic attack was reported in 1.2%. Access site complications that required intervention occurred in 4.1%. CONCLUSIONS: The available cohort and case series data support stent-graft repair as a highly successful technique that may reduce mortality and paraplegia rates by half compared with open surgery. These data support endograft repair as first-line therapy for blunt thoracic aortic trauma.

Summation of CT scans during radiofrequency ablation for assessing target lesion coverage.

OBJECTIVE: In radiofrequency ablation of lesions that require probe repositioning, distinguishing between treated and untreated regions can be difficult. We describe a method of using existing CT equipment to summate images of a current probe placement with those of earlier placements or scans of transiently enhancing targets. CONCLUSION: Summation of CT scans during radiofrequency ablation involving multiple probe placements is feasible and results in a better appreciation of probe positioning relative to the target lesion.

Aspirin treatment is associated with a significantly decreased risk of Staphylococcus aureus bacteremia in hemodialysis patients with tunneled catheters.

BACKGROUND: Hemodialysis patients with tunneled catheters are at increased risk of bacteremic Staphylococcus aureus infections. In vitro and in vivo studies showed that aspirin has direct antistaphylococcal effects by inhibiting expression of alpha-toxin and matrix adhesion genes through activation of sigma factor B stress-induced operon. We hypothesized that long-term treatment with aspirin may decrease the frequency of S aureus bacteremia in such patients. METHODS: We retrospectively analyzed electronic medical records for a variety of clinical parameters, including catheter dwell times, blood culture results, and aspirin use in our dialysis population. RESULTS: A total of 4,722 blood cultures were performed in 872 patients during more than 476 patient-catheter-years. There was a lower rate of catheter-associated S aureus bacteremia in patients treated with aspirin versus those not treated with aspirin (0.17 versus 0.34 events/patient-catheter-year, P = 0.003), whereas no such difference was observed for other bacteria. This association was dose dependent, seen mostly with the 325-mg aspirin dose. Using the Cox proportional hazard method, risk to develop a first episode of S aureus bacteremia decreased by 54% in patients using aspirin (confidence interval, 24 to 72; P = 0.002). Aspirin was associated with decreased risk of: (1) a first episode of methicillin-resistant S aureus bacteremia and (2) metastatic complications during the first episode of catheter-related S aureus bacteremia. CONCLUSION: These data are consistent with our clinical hypothesis that aspirin has a clinically useful antistaphylococcal effect in the dialysis population.

Hypersplenism in liver disease and SLE revisited: current evidence supports an active rather than passive process.

BACKGROUND: Active and passive theories have been advanced to explain splenomegaly and cytopenias in liver disease. Dameshek proposed active downregulation of hematopoiesis. Doan proposed passive trapping of blood components in a spleen enlarged by portal hypertension. Recent findings do not support a passive process. DISCUSSION: Cytopenias and splenomegaly in both liver disease and systemic lupus erythematosus (SLE) poorly correlate with portal hypertension, and likely reflect an active process allocating stem cell resources in response to injury. Organ injury is repaired partly by bone-marrow-derived stem cells. Signaling would thus be needed to allocate resources between repair and routine marrow activities, hematologic and bone production. Granulocyte-colony stimulating factor (G-CSF) may play a central role: mobilizing stem cells, increasing spleen size and downregulating bone production. Serum G-CSF rises with liver injury, and is elevated in chronic liver disease and SLE. Signaling, not sequestration, likely accounts for splenomegaly and osteopenia in liver disease and SLE. The downregulation of a non-repair use of stem cells, bone production, suggests that repair efforts are prioritized. Other non-repair uses might be downregulated, namely hematologic production, as Dameshek proposed. SUMMARY: Recognition that an active process may exist to allocate stem-cell resources would provide new approaches to diagnosis and treatment of cytopenias in liver disease, SLE and potentially other illnesses.

Safety and efficacy of the Gunther Tulip retrievable vena cava filter: midterm outcomes.

PURPOSE: To evaluate of the medium-term integrity, efficacy, and complication rate associated with the Gunther Tulip vena cava filter. METHODS: A retrospective study was performed of 369 consecutive patients who had infrarenal Gunther Tulip inferior vena cava filters placed over a 5-year period. The mean patient age was 61.8 years, and 59% were men. Venous thromboembolic disease and a contraindication to or complication of anticoagulation were the indications for filter placement in 86% of patients; 14% were placed for prophylaxis in patients with a mean of 2.3 risk factors. Follow-up was obtained by review of medical and radiologic records. RESULTS: Mean clinical follow-up was 780 days. New or recurrent pulmonary embolus occurred in 12 patients (3.3%). New or recurrent deep-vein thrombosis occurred in 53 patients (14.4%). There were no symptomatic fractures, migrations, or caval perforations. Imaging follow-up in 287 patients (77.8%) at a mean of 731 days revealed a single (0.3%) asymptomatic fracture, migration greater than 2 cm in 36 patients (12.5%), and no case of embolization. Of 122 patients with CT scans, asymptomatic perforations were identified in 53 patients (43.4%) at a mean 757 days. CONCLUSION: The Gunther Tulip filter was safe and effective at 2-year follow-up. Complication rates were similar to those reported for permanent inferior vena cava filters.

Value of immediate preprocedure magnetic resonance imaging in patients scheduled to undergo vertebroplasty or kyphoplasty.

STUDY DESIGN: Retrospective case series. OBJECTIVE: To determine the incidence of additional vertebral compression fractures diagnosed with repeat MRI immediately before vertebroplasty or kyphoplasty. SUMMARY OF BACKGROUND DATA: Vertebral compression fractures, which occur frequently in the elderly, are more likely in patients with prior vertebral compression fracture. When patients are evaluated for vertebroplasty, it is important to identify all unhealed fractures for effective treatment planning. METHODS: In a retrospective study, we reviewed the records of all patients (n = 194) treated with vertebroplasty or kyphoplasty over a 6-year period at our institution, and identified all patients who had undergone a repeat MRI within 7 days of vertebroplasty or kyphoplasty. These studies were obtained as part of a clinical protocol prescribing a repeat MRI for any patient whose MRI had been obtained more than 3 months before the evaluation, or who had a change in their pain between referral and evaluation. RESULTS: Twenty patients met inclusion criteria for the immediate preprocedure MRI protocol. A total of 14 new fractures in 11 patients were discovered on the immediate preprocedure MRI. Of these 14, 6 had less than 15% loss of height, making them potentially occult on radiographs; 3 fractures developed in 2 patients who had no change in back pain. CONCLUSION: In select candidates for vertebroplasty or kyphoplasty, a repeat preprocedure MRI obtained within 1 week can help ensure that all painful fractures are treated. There is demonstrable value in this protocol for patients with an imaging evaluation over 3 months old or who have had any change in symptoms since the initial imaging workup.

ACR Appropriateness Criteria on percutaneous catheter drainage of infected fluid collections.

Abnormal fluid collections occur throughout the body and represent a wide range of pathologies, including abscesses, pseudocysts, cysts, lymphoceles, seromas, bilomas, hematomas, urinomas, and infected neoplasms. Appropriate management often depends on clinical presentation, location, type of collection, early response to treatment, and the presence of complicating factors such as fistulas, septations, and increased viscosity. Physicians should carefully review clinical and imaging findings and make evidence-based recommendations for the best treatment, which may include antibiotics, needle aspiration, percutaneous drainage, endoscopic drainage, or surgical drainage. This paper addresses percutaneous catheter drainage and alternative treatment options for the management of fluid collections and is the result of evidence-based consensus by the ACR Appropriateness Criteria Expert Panel on Interventional Radiology.

Digital three-dimensional modelling of the male pelvis and bicycle seats: impact of rider position and seat design on potential penile hypoxia and erectile dysfunction.

OBJECTIVE: To digitally model (three-dimensional, 3D) the course of the pudendal arteries relative to the bony pelvis in the adult male, and to identify sites of compression with different bicycle riding positions as a potential cause of penile hypoxia and erectile dysfunction. SUBJECTS AND METHODS: 3D models were made from computed tomography scans of one adult male pelvis (a healthy volunteer) and three bicycle seats. Models were correlated with lateral radiographs of a seated rider to determine potential vascular compression between the bony pelvis and seats at different angles of rider positioning. RESULTS: Pelvis/seat models suggest that the most likely site of compression of the internal pudendal artery is immediately below the pubic symphysis, especially with the rider leaning forward. For an upright rider, the internal pudendal arteries do not appear to be compressed between the seat and the bony pelvis. Leaning partly forward with arms extended, the seat/symphysis areas were reduced to 73 mm(2) with standard seat and 259 mm(2) with a grooved seat. Leaning fully forward, the seat/symphysis areas decreased (no space with standard seat; 51 mm(2) with a grooved seat) and both the ischial tuberosities and the pubic symphysis might be in contact with the seat. CONCLUSION: A grooved seat allows better preservation of the seat/symphysis space than a standard seat, but the rider's position is more important for preserving the seat-symphysis space (and reducing compression) than is seat design alone. Any factors which influence the seat-symphysis space (including an individual's anatomy, seat design and rider position) can increase the potential for penile hypoxia and erectile dysfunction/perineal numbness.