nitinol and Pulmonary-Embolism

To report the final 2-year data on the efficacy and safety of a nitinol retrievable inferior vena cava (IVC) filter for protection against pulmonary embolism (PE).. This was a prospective multicenter trial of 200 patients with temporary indications for caval filtration who underwent implantation of the Denali IVC filter. After filter placement, all patients were followed for 2 years after placement or 30 days after filter retrieval. The primary endpoints were technical success of filter implantation in the intended location and clinical success of filter placement and retrieval. Secondary endpoints were incidence of clinically symptomatic recurrent PE, new or propagating deep vein thrombosis (DVT), and filter-related complications including migration, fracture, penetration, and tilt.. Filter placement was technically successful in 199 patients (99.5%). Filters were clinically successful in 190 patients (95%). The rate of PE was 3% (n = 6), with 5 patients having a small subsegmental PE and 1 having a lobar PE. New or worsening DVT was noted in 26 patients (13%). Filter retrieval was attempted 125 times in 124 patients and was technically successful in 121 patients (97.6%). The mean filter dwell time at retrieval was 200.8 days (range, 5-736 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of filter retrieval or during follow-up.. The Denali IVC filter exhibited high success rates for filter placement and retrieval while maintaining a low complication rate in this clinical trial.

Topics: Adult; Aged; Alloys; Device Removal; Female; Humans; Male; Middle Aged; Phlebography; Prospective Studies; Prosthesis Design; Prosthesis Implantation; Pulmonary Embolism; Time Factors; Treatment Outcome; United States; Vena Cava Filters; Vena Cava, Inferior; Venous Thrombosis

To assess safety and effectiveness of a nitinol retrievable inferior vena cava (IVC) filter in patients who require caval interruption to protect against pulmonary embolism (PE).. Two hundred patients with temporary indications for an IVC filter were enrolled in this prospective, multicenter clinical study. Patients undergoing filter implantation were to be followed for 2 years or for 30 days after filter retrieval. At the time of the present interim report, all 200 patients had been enrolled in the study, and 160 had undergone a retrieval attempt or been followed to 6 months with their filter in place. Primary study endpoints included technical and clinical success of filter placement and retrieval. Patients were also evaluated for recurrent PE, new or worsening deep vein thrombosis, and filter migration, fracture, penetration, and tilt.. Clinical success of placement was achieved in 94.5% of patients (172 of 182), with a one-sided lower limit of the 95% confidence interval of 90.1%. Technical success rate of filter placement was 99.5%. Technical success rate of retrieval was 97.3%; 108 filters were retrieved in 111 attempts. In two cases, the filter apex could not be engaged with a snare, and one device was engaged but could not be removed. Filter retrievals occurred at a mean indwell time of 165 days (range, 5-632 d). There were no instances of filter fracture, migration, or tilt greater than 15° at the time of retrieval or 6-month follow-up.. In this interim report, the nitinol retrievable IVC filter provided protection against pulmonary embolism, and the device could be retrieved with a low rate of complications.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Alloys; Device Removal; Female; Humans; Male; Middle Aged; Prospective Studies; Prosthesis Design; Pulmonary Embolism; Recurrence; Risk Factors; Time Factors; Treatment Outcome; United States; Vena Cava Filters; Venous Thrombosis; Young Adult

The Simon nitinol filter for percutaneous interruption of the vena cava to prevent pulmonary embolism is currently undergoing a multicenter clinical trial. Preliminary clinical results are reported as work in progress. The results in 44 patients at two centers are analyzed in detail, and major events are reported from 103 patients in 17 centers in the United States during a 10-month period. The filter was successfully inserted via the femoral or jugular route in all patients through a 9-F catheter. The placement procedure was easy and without significant complications. Follow-up studies included plain radiography, ultrasonography, magnetic resonance (MR) imaging, and clinical evaluation. No filter migration or perforation occurred among the 103 patients. Symptomatic occlusions occurred in 7%-9%, comparable to other series, and some asymptomatic occlusions were detected with MR imaging only. The implications of occlusion of the filter are discussed.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Clinical Trials as Topic; Female; Filtration; Humans; Male; Middle Aged; Multicenter Studies as Topic; Pulmonary Embolism; Radiography; Vena Cava, Inferior

The Simon Nitinol filter is a bi-level filtration device designed for permanent implantation that is no longer commercially available, but may result in similar complications to current commercially available long term indwelling temporary or permanent filters. Complications related to indwelling inferior vena cava filters include inferior vena cava thrombosis, inferior vena cava penetration, filter migration, and filter fracture. There is a paucity of reports describing the technical aspects related to retrieval of Simon Nitinol filters.. This study consisted of five patients with Simon Nitinol filters and describes the indication for retrieval, the retrieval techniques used to remove the filters, technical success, complications, and clinical course.. The indications for retrieval included: abdominal pain (. Simon Nitinol filters may be retrieved safely and effectively using advanced inferior vena cava filter retrieval techniques.

Topics: Alloys; Device Removal; Humans; Pulmonary Embolism; Retrospective Studies; Treatment Outcome; Vena Cava Filters; Vena Cava, Inferior

Mechanical right ventricular (RV) support offers a treatment option for critically ill patients with RV failure (RVF). We developed an assist device for rapid percutaneous implantation. The aim of the present study was to investigate the implantation procedure, haemodynamic performance and possible side effects of the novel right ventricular assist device - PERKAT RV - in an animal model.. The PERkutane KATheterpumptechnologie RV (PERKAT RV) device consists of a nitinol chamber covered by foil containing inflow valves. An outlet tube is attached to its distal part. The system is designed for 18 Fr percutaneous implantation. The chamber is unfolded in the inferior vena cava while the outlet tube bypasses the right heart with the tip in the pulmonary trunk. An IABP balloon is placed inside. Balloon deflation generates blood flow into the chamber; during inflation, blood is guided into the pulmonary arteries. Acute RVF was induced by venous injection of Sephadex in seven sheep for evaluation of the device. The PERKAT RV was able to improve haemodynamics immediately generating a median increase in cardiac output of 59%. Longer pump support was evaluated in a second study. Four sheep were supported for eight hours without any problems.. The percutaneous implantation and explantation of the PERKAT RV device was possible in the designed way. The sheep studies proved beneficial haemodynamic effects in acute RVF. The system offers easy and safe treatment in acute RVF.

Topics: Alloys; Animals; Device Removal; Disease Models, Animal; Female; Heart Failure; Heart-Assist Devices; Hemodynamics; Intra-Aortic Balloon Pumping; Prosthesis Design; Prosthesis Implantation; Pulmonary Embolism; Sheep, Domestic; Stents; Time Factors; Ventricular Function, Right

Pulmonary embolism (PE) is a potentially life-threatening complication of critical illness. In trauma and neurosurgical patients with contraindications to anticoagulation, inferior vena cava (IVC) filters have been used to prevent PE, but their associated long-term complication rates and difficulties associated with filter removal have limited their use. The Angel catheter is a temporary device, which combined an IVC filter with a triple-lumen central venous catheter (IVC filter-catheter) and is intended for bedside placement and removal when no longer indicated.. This study presents data from a European Registry of 60 critically ill patients in whom the IVC filter-catheter was used to prevent PE. The patients were all at high risk of PE development or recurrence and had contraindications to anticoagulation. The primary end points of this study were to evaluate the safety (in particular, the presence of infectious or thrombotic events) and effectiveness (the numbers of PEs and averted PEs) of the IVC filter-catheter.. The main diagnosis before catheter insertion was major trauma in 33 patients (55%), intracerebral hemorrhage or stroke in 9 (15%), a venous thromboembolic event in 9 (15%), and active bleeding in 6 (10%). The IVC filter-catheter was placed as prophylaxis in 51 patients (85%) and as treatment in the 9 patients (15%) with venous thromboembolic event. The devices were inserted at the bedside without fluoroscopic guidance in 54 patients (90%) and within a median of 4 days after hospital admission. They were left in place for a mean of 6 days (4-8 days). One patient developed a PE, without hemodynamic compromise; two PEs were averted. No serious adverse events were reported.. Early bedside placement of an IVC filter-catheter is possible, and our results suggest that this is a safe, effective alternative to short-term PE prophylaxis for high-risk patients with contraindications to anticoagulation.. Therapeutic study, level V.

Topics: Adult; Alloys; Catheterization, Central Venous; Critical Illness; Europe; Female; Humans; Male; Middle Aged; Pulmonary Embolism; Registries; Risk Factors; Treatment Outcome; Vena Cava Filters

Inferior vena cava (IVC) filters are used to treat thromboembolic disease when there is a contraindication to anticoagulation or failure of therapeutic anticoagulation therapy. Although there are retrievable IVC filters available, permanent IVC filters remain the most commonly placed IVC filters worldwide. Permanent IVC filters have been associated with long-term complications such as IVC thrombosis and obstruction, migration, and erosion into surrounding structures. Such complications may require removal of permanent IVC filters, which has been previously described with open surgery involving venotomy of the IVC. We report a case of a Bard Simon Nitinol permanent IVC filter that was removed by using percutaneous endovascular techniques.

Topics: Adult; Alloys; Anticoagulants; Arthroplasty; Device Removal; Endovascular Procedures; Humans; Male; Phlebography; Prosthesis Design; Pulmonary Embolism; Tomography, X-Ray Computed; Treatment Outcome; Vena Cava Filters; Venous Thrombosis

An anomalous systemic artery originating from the descending thoracic aorta supplying the normal basal segments of the lower lobe of the left lung without sequestration is a rare congenital anomaly. The published surgical treatments include lobectomy, segmentectomy, anastomosis, and ligation. In addition, endovascular treatment with coils has been reported. A second-generation occluder, the Amplatzer Vascular Plug II (AVP II), has a central plug and two occlusion disks and a finer, more densely woven nitinol wire, thus enabling faster embolization. This published case is the first successful occlusion of an aneurysm of an anomalous systemic artery with the AVP II and fibered coils, with 10 months of follow-up.

Topics: Alloys; Aneurysm; Angiography; Aorta, Thoracic; Chest Pain; Embolization, Therapeutic; Equipment Design; Follow-Up Studies; Humans; Lung; Male; Middle Aged; Pulmonary Artery; Pulmonary Embolism; Septal Occluder Device; Tomography, Spiral Computed; Treatment Outcome

To evaluate the clot-trapping ability, stability, and migration of a new low-profile, retrievable inferior vena cava (IVC) filter in an in-vitro model.. The SafeFlo IVC filter consists of two superelastic nitinol wires that form a double-ring platform and spiral filter. The filter is collapsed into a 5-6-F catheter and delivered into the IVC model. The in-vitro model closely simulates the physical parameters of flow in the human IVC. Human blood clots of 2-mm and 4-mm diameters and 3-cm lengths were injected into the flow system in sets of five clots. Filter delivery and retrieval were performed in every series. Filtration was evaluated in IVC models of 20-mm and 24-mm lumen diameter in vertical and horizontal positions. Stability and migration of the filter were evaluated by direct vision of maintenance of position and shape before and after clot trapping.. Filter delivery and retrieval were straightforward and repeatable in a total of 20 procedures. The filters maintained shape and position throughout the study. A total of 248 clots were injected and 225 (90.7%) were trapped. The individual tests in horizontal and vertical positions with either clot size demonstrated trapping rates of 85.7%-97.1%.. The SafeFlo IVC filter is a stable and effective filter in an in-vitro model. The filter design is amenable to simple delivery and retrieval.

Topics: Alloys; Blood Coagulation; Coated Materials, Biocompatible; Device Removal; Equipment Design; Equipment Reuse; Equipment Safety; Foreign-Body Migration; Humans; Models, Cardiovascular; Pulmonary Embolism; Vena Cava Filters

The nitinol TrapEase inferior vena cava filter is a new device for pulmonary embolism prophylaxis. No cases of filter migration or filter-related complications with this type of device have so far been described. We report a case of intracardiac migration of this filter in a patient with a patent foramen ovale, resulting in severe cardiogenic shock, cerebral and right arm paradoxical embolism. Surgical treatment, results, causes of these complications are discussed.

Topics: Alloys; Brachial Artery; Cardiac Surgical Procedures; Embolism, Paradoxical; Foreign-Body Migration; Heart Septal Defects, Atrial; Heart Ventricles; Humans; Intracranial Embolism; Male; Middle Aged; Pulmonary Embolism; Vena Cava Filters

To evaluate preliminary clinical experience in humans with the Recovery nitinol filter (RNF) for the inferior vena cava, especially the efficacy of the device and safety of its retrieval.. Thirty-two patients were followed up to assess for filter efficacy and for ability to remove the filter.. Sixteen men and 16 women aged 18-83 years (mean, 53 years) underwent treatment with the RNF. Indications for placement were recent pulmonary embolism (n = 16), recent deep venous thrombosis (n = 20), and/or prophylaxis (n = 2). Four patients had contraindications to anticoagulant therapy, and four had complications from anticoagulant therapy. The filter was successfully placed in 32 patients. In 24 (100%) of 24 patients, the filter was successfully retrieved with a jugular approach. The mean implantation period was 53 days (range, 5-134 days). Trapped thrombus was seen within the filter in seven cases. In one patient with a large trapped thrombus, the filter was noted to have migrated 4 cm cephalad. There were no episodes of pulmonary embolism or insertion-site thrombosis.. This preliminary experience in humans confirms the efficacy of the RNF. It also demonstrates the feasibility and safety of retrieval up to 134 days after implantation.

Topics: Alloys; Device Removal; Feasibility Studies; Female; Femoral Vein; Humans; Male; Middle Aged; Pulmonary Embolism; Thrombosis; Time Factors; Tomography, X-Ray Computed; Vena Cava Filters; Vena Cava, Inferior

The authors report the first results of a new 6-F symmetrically designed permanent nitinol inferior vena cava (IVC) filter, the Cordis TrapEase, evaluated in a multicenter prospective study with 6-months of follow-up.. A total of 65 patients (29 men, 36 women) who ranged in age from 37 to 96 years (mean age, 68 years) and who were at high risk of pulmonary embolism (PE) were enrolled in 12 centers in Europe and Canada. The study was approved by the institutional review boards at all centers. Study objectives were to evaluate filter effectiveness, filter stability, and caval occlusion. Indications for filter placement were deep vein thrombosis with recurrent thromboembolism and/or free-floating thrombus with contraindication to anticoagulation in 37 patients, and complications in achieving adequate anticoagulation in 28 patients. Follow-up included clinical examination, plain film, Doppler ultrasound, CT scan, and nuclear medicine.. The analysis of the data revealed a technical success of 95.4% (three filter-system related implantations not at the intended site, no events of filter tilting) and a clinical success of 100% at 6 months (no cases of symptomatic PE), the study primary endpoint. There were no cases (0%) of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study period, there were two cases of filter thrombosis: one case of early symptomatic thrombosis that was successfully treated in the hospital, and one case of nonsymptomatic filter thrombosis detected at 1-month follow-up, with spontaneous recanalization at 3 months. In the latter patient, some residual thrombus was still detected at 6 months. Of the study population of 65 patients, there were 23 deaths. These deaths were not related to the device or the implantation procedure but to the underlying disease process.. This study demonstrates the new nitinol permanent IVC filter to be a safe and an effective device, with a low overall complication rate, for use in patients with thromboembolic disease at high risk of PE.

Topics: Aged; Alloys; Canada; Equipment Design; Europe; Female; Follow-Up Studies; Humans; Male; Prospective Studies; Pulmonary Embolism; Risk; Time Factors; Vena Cava Filters; Venous Thrombosis

Simon nitinol vena cava filters: effectiveness and complications.. The aim of this retrospective analysis was to evaluate the clinical safety and effectiveness of the Simon Nitinol inferior vena cava filter (SNF) for prevention of pulmonary embolism.. 117 patients (63 male, 54 female; aged 58.38 +/- 14.59 years) underwent percutaneous implantation of an SNF from 1993 through 1999. Patient reports were retrospectively analysed for complications during and after implantation and deep venous thrombosis (DVT) and pulmonary embolism before and after implantation. Helical-CT with contrast media and plain abdominal radiography were performed on 35 patients, helical-CT alone on two patients. We checked the position and configuration of the SNF and looked for a perforation of the filter legs through the wall of the inferior vena cava (IVC). The IVC and deep pelvic veins were analysed for patency.. During implantation 10 of 117 (9 %) patients had minor complications, major complications were reported in 0.9 % (1/117). There was no significant increase in thrombosis of the deep pelvic veins and the IVC after implantation. Pulmonary re-embolism (PE) was documented in 9 out of 117 patients (7.7 %). One out of the 35 examined patients (2.9 %) showed a single strut fracture of the SNF. Tilting more than 15 degrees was seen in 7 out of 37 patients (19 %). Dislocation of the SNF more than 10 mm occurred in one out of 35 patients (2.9 %), perforation through the wall of the IVC in all 37 patients. We found no occlusion of the IVC.. The SNF is easy and safe to implant and successfully prevents pulmonary embolism. In our study the rate of well documented pulmonary re-embolism (7.7 %) is satisfactory. Except for the high perforation rate through the wall of the IVC (100 %, but without clinical relevance), complication rates during and after implantation of the SNF are low compared with other filter types.

Topics: Adult; Aged; Alloys; Equipment Failure; Equipment Safety; Female; Humans; Male; Middle Aged; Pulmonary Embolism; Tomography, X-Ray Computed; Vena Cava Filters

Topics: Adult; Alloys; Catheterization, Peripheral; Equipment Design; Femoral Vein; Humans; Iliac Vein; Male; Pulmonary Embolism; Vena Cava Filters; Vena Cava, Inferior

The aim of this study was to evaluate the clinical efficacy, mechanical stability, and safety of the Simon nitinol inferior vena cava filter (SNF). The SNF was inserted in 114 consecutive patients at two institutions for prophylaxis of pulmonary embolism (PE). Clinical follow-up data were obtained retrospectively on all patients, and 38 patients underwent a dedicated radiologic follow-up protocol consisting of abdominal radiography, Doppler sonography, and CT. There was no immediate complication following filter insertion. Fifty patients died, on average, 5.6 (1-23) months after filter insertion, and 64 patients were alive, on average, 27 (3-62) months after filter insertion. Recurrent pulmonary embolism was documented in 5 patients (4.4 %) but originated distal to the filter in 1 patient. Deep venous thrombosis (DVT) was documented in 5.3 %, thrombosis at the access site in 3.5 %, and thrombosis of the inferior vena cava in 3.5 %. The rate of thromboembolic complications was similar in patients who did receive long-term anticoagulation and in those who did not. Radiologic follow-up showed no filter migration after, on average, 32 (5-62) months. A CT examination showed that struts of the SNF had penetrated the vena cava in 95 %, and were in contact with adjacent organs in 76 %; however, there were no clinical symptoms attributable to the filter. Filters were in an eccentric position in 63 % and partial filter disruption was found in 16 %; however, this did not affect filter function. The rate of recurrent pulmonary embolism after insertion of the SNF is 2.4 % per patient per year. Regardless of long-term anticoagulation, the rate of caval thrombosis is acceptably low. Except for occasional access-site thrombosis, no other filter-related morbidity was observed.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Equipment Failure; Evaluation Studies as Topic; Female; Follow-Up Studies; Humans; Male; Middle Aged; Pulmonary Embolism; Radiography, Abdominal; Recurrence; Thrombophlebitis; Tomography, X-Ray Computed; Ultrasonography, Doppler; Vena Cava Filters

Simon nitinol vena caval filters were placed percutaneously in 20 patients. Follow-up (average, 14 months) data were available for 16 patients, and four patients were lost to follow-up. There were no proved or suspected cases of pulmonary embolism after filter insertion. Complications encountered included caval penetration (n = 5, one acute and four at follow-up), caval thrombus (n = 4, two determined radiologically and two clinically), postplacement deep venous thrombosis (n = 2, one radiologic and one clinical), filter migration (n = 1), and delayed fracture of a filter leg (n = 2). Although no deaths or significant morbidity resulted from any complication, the relatively high complication rate, especially of significant caval penetration (documented in 25% of filter insertions), merits continued short- and long-term assessment of patient status after filter placement.

Topics: Adult; Aged; Aged, 80 and over; Alloys; Female; Foreign-Body Migration; Humans; Male; Middle Aged; Pulmonary Embolism; Radiography; Thrombosis; Vena Cava Filters; Vena Cava, Inferior

To determine the biocompatibility and thrombogenicity of nitinol blood clot filters, we inserted 27 nitinol wire devices into the venae cavae of 16 dogs and one sheep and studied the results angiographically and at autopsy after periods of one week to four years. Filter shape, location in the vena cava, wire cleaning procedure and wire surface finish were varied. All 18 cleaned nitinol wire filters remained patent by venogram, although some showed small venographic filling defects caused by adherent organized thrombi. Filters in larger veins tended to have less thrombus. Surface polishing and filter shape had no observable effect on thrombogenicity. Histologic study revealed patchy chronic inflammation at the surface of uncleaned filters but only benign fibrous tissue reaction for the cleaned filters. Neointimal tissue overgrowth was observed where nitinol wire contacted the wall of the vena cava. Two filters implanted for four years had no appreciable weight loss caused by corrosion. Platelet adhesion and plasma coagulation effects of nitinol wire were tested in vitro in human blood and found to be similar to those of stainless steel, which is used in comparable devices. These encouraging results suggest that nitinol may be a promising material for human intravascular prosthetic applications.

Topics: Alloys; Animals; Biocompatible Materials; Dogs; Filtration; Foreign-Body Reaction; Pulmonary Embolism; Sheep; Thrombosis; Venae Cavae

An inferior vena cava filter made from nitinol, a thermal shape memory alloy, was evaluated. A series of in vitro experiments was designed to assess its shape recovery, orientation, and positioning after delivery and its embolus-capturing efficiency. For comparison, the Mobin-Uddin and Kimray-Greenfield filters were also tested. The results indicate that the nitinol filter is easily and accurately delivered and is superior to the other filters in its ability to capture emboli. In addition, it showed no tendency to migrate or to elevate the upstream hydrostatic pressures significantly.

Topics: Alloys; Filtration; Humans; In Vitro Techniques; Prostheses and Implants; Pulmonary Embolism; Vena Cava, Inferior