Experimental superior vena caval placement of the Greenfield filter (original) (raw)
Related papers
Journal of Vascular and Interventional Radiology, 2020
Purpose: To prospectively evaluate the initial human experience with an absorbable vena cava filter designed for transient protection from pulmonary embolism (PE). Materials and Methods: This was a prospective, single-arm, first-inhuman study of 8 patients with elevated risk of venous thromboembolism (VTE). Seven absorbable IVC filters (made of polydioxanone that breaks down into H 2 O and CO 2 in 6 mo) were placed prophylactically before orthopedic (n ¼ 5) and gynecologic (n ¼ 2) surgeries, and 1 was placed in a case of deep vein thrombosis. Subjects underwent CT cavography and abdominal radiography before and 5, 11, and 36 weeks after filter placement to assess filter migration, embolization, perforation, and caval thrombosis and/or stenosis. Potential PE was assessed immediately before and 5 weeks after filter placement by pulmonary CT angiography. Results: No symptomatic PE was reported throughout the study or detected at the planned 5-week follow-up. No filter migration was detected based on the fixed location of the radiopaque markers (attached to the stent section of the filter) relative to the vertebral bodies. No filter embolization or caval perforation was detected, and no caval stenosis was observed. Throughout the study, no filter-related adverse events were reported. Conclusions: Implantation of an absorbable vena cava filter in a limited number of human subjects resulted in 100% clinical success. One planned deployment was aborted as a result of stenotic pelvic veins, resulting in 89% technical success. No PE or filter-related adverse events were observed. ABBREVIATIONS AE ¼ adverse event, AP ¼ anterior/posterior, DVT ¼ deep vein thrombosis, IVC ¼ inferior vena cava, PDS ¼ polydioxanone suture, PE ¼ pulmonary embolism, VTE ¼ venous thromboembolism Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a leading cause of death and disability worldwide. Bestpractice VTE prevention begins with pharmaceutical anticoagulation, including heparin, vitamin K antagonists, and factor Xa inhibitors. However, anticoagulant agents are often temporarily contraindicated because of bleeding or impending surgery. For patients presenting with VTE for From the Department of Radiology (G.
Inferior vena cava filters in pulmonary embolism: A historic controversy
Archivos de cardiologia de Mexico, 2017
Rationale for non-routine use of inferior venous cava filters (IVCF) in pulmonary embolism (PE) patients. Thrombosis mechanisms involved with IVCF placement and removal, the blood-contacting medical device inducing clotting, and the inorganic polyphosphate in the contact activation pathway were analyzed. In addition, we analyzed clinical evidence from randomized trials, including patients with and without cancer. Furthermore, we estimated the absolute risk reduction (ARR), the relative risk reduction (RRR), and the number needed to treat (NNT) based on the results of each study using a frequency table. Finally, we analyzed the outcome of our PE patients that were submitted to thrombolysis with short and long term follow-up. IVCF induces thrombosis by several mechanisms including placement and removal, rapid protein adsorption, and simultaneous surface-induced activation via the contact activation pathway. Also, inorganic polyphosphate has an important role as a procoagulant, reversi...
The Günther temporary inferior vena cava filter for short-term protection against pulmonary embolism
Cardiovascular and Interventional Radiology, 1997
Purpose: To evaluate clinically the GUnther temporary inferior vena cava (IVC) filter. Methods: Eleven IVC filters were placed in 10 patients. Indications for filter placement were surgical pulmonary embolectomy in seven patients, pulmonary embolism in two patients, and free-floating iliofemoral thrombus in one patient. Eight filters were inserted from the right femoral approach, three filters from the left. Follow-up was by plain abdominal radiographs, cavography, and duplex ultrasound (US). Eight patients received systemic heparinization. Follow-up, during 4-60 months after filter removal was by clinical assessment, and imaging of the lungs was performed when pulmonary embolism (PE) was suspected. Patients received anticoagulation therapy for at least 6 months. Results: Ten filters were removed without complications 7-14 days (mean 10 days) after placement. One restless patient pulled the filter back into the common femoral vein, and a permanent filter was placed. In two patients a permanent filter was placed prior to removal. One patient developed sepsis, and one an infection at the insertion site. Clinically no recurrent PE developed with the filter in place or during removal. One patient had recurrent PE 7 months after filter removal. Conclusion: The Gtinther temporary IVC filter can be safely placed for short-term protection against PE. The use of this filter is not appropriate in agitated or immunocompromised patients.
Effect of anticoagulation on the lysis of filter entrapped thromboembolism in dogs
Journal of Surgical Research, 1985
Resolution of thrombi entrapped in Greenfield vena caval filters is a primary mechanism for maintenance of caval patency with this device following an embolic event. In order to determine if anticoagulation is beneficial in this setting, thrombus was harvested from 65 mongrel dogs with infrarenal IVC thrombosis after phenolization. These thrombi were weighed and emboliied into Greenfield filters placed above the renal veins. The inharenal IVCs were then ligated and the animals allowed to recover. Beginning the first postoperative day, animals were given either oral coumadin daily to elevate the prothrombin time above 1.5 normal, subcutaneous heparin 500 u/kg/day divided into two doses, or received no treatment. They were sacrificed either 1,2, 3, or 4 weeks after embolism and the residual thrombi weighed. Initial thrombus weights were similar for each period (differences NS). Comparison of initial with final weights revealed that both coumadin and heparin-treated animals had a significantly increased resolution in the first week when compared to controls. By 2 weeks, however, there were no significant differences between the groups, and controls proceeded to a mean of 95% resolution by 4 weeks. A general linear model used to separate the effects of treatment, time, and initial thrombus weight showed that resolution was primarily a function of initial thrombus weight, and of time. Coumadin was marginally beneficial. Thrombus resolution proceeds rapidly in this model without anticoagulation. These data suggest that prevention of deep vein thrombosis and its sequelae remain the sole indication for anticoagulation after filter placement. 8
Multiple Emboli and Filter Function: An in Vitro Comparison of Three Vena Cava Filters
Journal of Vascular and Interventional Radiology, 1995
Abbreviations: CI = confidence interval, GT = Gunther Tulip retrievable filter, IVC = inferior vena cava, TG = titanium Greenfield filter, VT = Vena Tech-LGM filter PURPOSE: To establish the influence of number of emboli on the trapping ability of vena cava filters in vitro. MATERIALS AND METHODS: Three filters, the titanium Greenfield, Vena Tech-LGM, and Gunther Tulip retrievable, were studied with use of 20-or 26-mm-diameter tubes to simulate the inferior vena cava. In the first protocol, five small (4 x 20-mm) or medium (6 x 10-mm) emboli were delivered in sequence, and the fate of each was recorded. In the second protocol, medium or large (6 x 30-mm) clots were sequentially introduced until filter occlusion occurred or 50 clots had been delivered. RESULTS: For the first protocol, 82% of first small clots and 60% of second clots were trapped in 20-mm tubes (P =.001) and 63% and 45%, respectively, were trapped in 26-mm tubes (P =.02). With medium clots, the proportion trapped also dropped significantly with ascending clot rank. In the second protocol the proportion of clots captured was invariably higher for the first 10 clots (P < .001 for all combinations of covariables). CONCLUSION: Filter function deteriorates with number of emboli delivered, irrespective of embolus size and simulated vein caliber.
Respiratory Medicine, 2002
The use of inferior vena cava (IVC) filter for massive pulmonary emboli (PE) with cardiopulmonary instability has not been clinically studied. We present a case series of six such patients who received an IVC filter with anticoagulation rather than thrombolysis because of high risk of bleeding. Acute pulmonary embolectomy was considered, but was not possible for a variety of individual clinical situations. These six hospitalized patients prospectively followed during their admission. They were triaged to three medical intensive care units (ICUs) and one surgical ICU in three university teaching hospitals. One patient was transferred from another institution. All six patients had severe hypoxia and tenuous cardiopulmonary status. All required high inspiratory oxygen and hemodynamic support; two required mechanical ventilation and vasopressors. An IVC filter was placed emergently and anticoagulation was started immediately. All six patients had resolution of pulmonary thromboemboli (PTE) on anticoagulation while the IVC filter prevented further PE. All six patients were discharged home in their pre-critical illness state. None of the patients suffered complications from this therapy and had excellent resolution of cardiopulmonary collapse. The IVC filter placement prevented further major embolic events while the PTE resolved with anticoagulation. An IVC filter should be considered as an adjunct to anticoagulation therapy for those patients with massive PE and cardiopulmonary instability who are not candidates for thrombolysis, and acute pulmonary embolectomy is not readily available or is of very high risk.
Vena cava filters and inferior vena cava thrombosis
Journal of Vascular …, 2007
Retrievable vena cava filters (R-VCF) are a recent addition to the therapeutic armamentarium for the prevention of pulmonary embolism. However, unlike permanent vena cava filters (P-VCF), outcomes data are limited regarding complication rates. Methods: This was a retrospective comparative analysis of consecutive patients undergoing placement of R-VCF vs P-VCF at Wake Forest University School of Medicine from January 2000 to December 2004. Data collected included demographics, procedural specifics, filter type, indications, and complications. Summary data are expressed as number (percentage) or mean ؎ SD. Continuous and categorical variables were analyzed by using t and Fisher exact testing, as appropriate. Four additional patients with vena cava thrombosis were also referred to our institution for treatment during the study period, all with opposed biconical VCFs (OptEase and TrapEase filters) recently placed at other facilities. This last group of patients is described but not included in the analysis. Results: A total of 189 VCF (165 P-VCF and 24 R-VCF) cases were examined. No significant differences in VCF groups were observed according to age, documented hypercoagulability, or concomitant anticoagulation. Significant differences were observed according to sex (30.3% of P-VCF vs 62.5% of R-VCF patients were female), morbid obesity (4.2% of P-VCF vs 25% of R-VCF patients), active malignancy (20% of P-VCF vs 41.7% of R-VCF patients), and indication for VCF placement. Over a median follow-up of 8.5 months, no case of significant hemorrhage, no VCF migration, and four cases of vena cava thrombosis were observed. Vena cava thrombosis was observed more frequently in the presence of R-VCF when compared with P-VCF (12.5% vs 0.6%; P ؍ .007). All observed vena cava thromboses were associated with severe clinical symptoms and occurred in patients who received opposed biconical VCF designs. Conclusions: In our experience, both P-VCF and R-VCF can be placed safely. Among both permanent and retrievable devices, however, opposed biconical designs seem to be associated with an increased risk for vena cava thrombosis. Although causative factors remain unclear, filter design and resultant flow dynamics may play an important role, because all episodes of vena cava thrombosis occurred in patients with a single-filter design.
The late outcomes of vena cava filters in the prevention of pulmonary embolism
Ulusal travma ve acil cerrahi dergisi = Turkish journal of trauma & emergency surgery : TJTES, 2003
Pulmonary embolism (PE) is the most serious complication of deep venous thrombosis (DVT) resulting in high morbidity and mortality rate. The purpose of this study is to evaluate the long-term results of vena cava filters (VCFs) placement for prevention of PE in high- risk patients. Between June 1999 and March 2002, at the Trauma and Surgical Emergency Service of Istanbul Medical Faculty, 15 high-risk patients who underwent placement of filters were evaluated. There were eleven males (73%) and four females (27%) with mean age of 50 years (range 14 to 76). Eleven of VCFs were placed for prophylactic and four for therapeutic purposes. The indications of VCFs placement are as follows: Spinal cord injury with life-long paraplegia in eight and quadriplegia in two patients, venous thromboembolism while on anticoagulation in two patients, contraindications to anticoagulation in three patients. The mean duration of follow-up was 17 months (range 3-32 months). No patients developed DVT and re...