nitinol and Venous-Thrombosis

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 StarClose Vascular Closure System (Abbott Vascular, Redwood City, CA) features a nitinol clip that is designed to achieve closure of the femoral arteriotomy access site. The CLIP Study was performed to assess the safety and efficacy of StarClose when compared with standard manual compression following 5-6 French diagnostic or interventional percutaneous procedures. A substudy of this trial was designed to assess the utility of duplex ultrasonography to assess patency of the femoral artery and to determine access site complications (pseudoaneurysm, arteriovenous fistula, hematoma, deep vein thrombosis) in a multicenter prospective trial. This is the report of the duplex ultrasound (DUS) substudy of the CLIP trial.. A total of 17 U.S. sites enrolled 596 subjects with 483 subjects randomized at a 2:1 ratio to receive StarClose or manual compression of the arteriotomy after a percutaneous procedure. The study included roll-in (n = 113), diagnostic (n = 208), and interventional (n = 275) arms with a primary safety endpoint of major vascular complications through 30 days and a primary efficacy endpoint of postprocedure time to hemostasis. A substudy of the CLIP interventional arm evaluated DUS images of the closure site at five study sites, targeting 100 subjects at day 30 following hemostasis. The DUS protocol was devised and implemented by an independent vascular ultrasound core laboratory with extensive experience in vascular device trials. DUS inguinal region from 6 cm proximal to 6 cm distal to the arteriotomy puncture was performed. A qualitative examination was performed to determine the presence of iatrogenic vascular injuries: hematoma, pseudoaneurysm (PSA), arteriovenous fistula (AVF), and arterial/venous thrombosis or stenosis using 2-dimensional gray scale, color, and focused Doppler images.. DUS of 96 subjects randomized to StarClose (n = 71) and compression (n = 25) were performed and evaluated. There was no evidence of hematoma, PSA, or AVF observed in the StarClose group. No StarClose subjects in the substudy had a PSA or AVF. All patients in the substudy demonstrated patency of the access site artery and vein without thrombosis or stenosis. Finally, in the entire study cohort, no clinically-driven DUS studies demonstrated iatrogenic vascular injury or vessel thrombosis in the StarClose treated patients.. DUS, a safe and reliable method for determining the safety and efficacy of access site closure devices, is a reliable, safe, inexpensive and accurate method of assessing vascular access site complications in multicenter trials. In this substudy of the CLIP study, DUS found no statistical difference in access site complications between the StarClose and manual compression groups. Both groups maintained vessel patency without stenosis, thrombosis, hematoma, pseudoaneurysm, or AV fistula.

Topics: Adult; Aged; Alloys; Aneurysm, False; Arterial Occlusive Diseases; Arteriovenous Fistula; Cardiac Catheterization; Collateral Circulation; Equipment Design; Equipment Safety; Female; Femoral Artery; Femoral Vein; Follow-Up Studies; Hematoma; Hemostasis; Hemostatic Techniques; Humans; Male; Middle Aged; Postoperative Complications; Prospective Studies; Reproducibility of Results; Saphenous Vein; Surgical Instruments; Treatment Outcome; Ultrasonography, Doppler, Duplex; Ultrasonography, Interventional; Vascular Patency; Venous Thrombosis

The purpose of this study was to evaluate the feasibility, safety, and efficacy of portal vein recanalization (PVR) and propose a new classification for better selecting candidates with portal vein occlusion (PVO) in whom PVR could be feasible.. The charts of 15 non-cirrhotic patients in whom stent placement using a trans-hepatic approach was attempted for the treatment of PVO with cavernous transformation were reviewed. \ There were 12 men and 3 women with a mean age of 47 ± 12 years (range: 22–60 years) [corrected].\ Intrahepatic involvement was classified into 3 groups according to the intrahepatic extent of PVO: type 1 included occlusions limited to the origin of the main portal vein and/or the right or left portal branches, type 2 included type 1 plus extension to the origin of segmental branches, type 3 included type 2 plus extension to distal branches.. There were 6 patients with PVO type 1, 7 patients with PVO type 2, and 2 patients with PVO type 3. Indications for PVR were gastrointestinal bleeding (n=6), portal biliopathy (n=2), reduce portal pressure before surgery (n=4), or other (n=3). PVR was successful in 13 patients (87%) with no severe side effects. Failure of PVR or early stent thrombosis occurred in 100% of type 3 vs. 8% of type 1 and 2 patients (P=0.03). During a mean follow-up of 42±28 months (range: 6-112 months), patients with a permeable stent had resolution of portal hypertension-related manifestations. In 13 patients in whom PVR was feasible, stent permeability was 77% at 2 years (87% vs. 60% in patients who received anticoagulation or not, respectively; P=0.3).. PVR is feasible in most patients with non-cirrhotic, non-tumoral portal vein occlusion when there is no extension of the occlusion to distal branches.

Topics: Adult; Alloys; Feasibility Studies; Female; Follow-Up Studies; Humans; Hypertension, Portal; Liver Function Tests; Male; Middle Aged; Phlebography; Portal Vein; Stents; Venous Thrombosis; Young Adult

Occlusion of the inferior vena cava (IVC) often causes venous claudication, leg swelling, or skin changes. We hypothesized that the outcome of nitinol stents for endovascular reconstruction of the IVC is similar to the outcome reported for steel alloy stents.. From the prospective Bern Venous Stent Registry, we investigated technical success, patency rates, and clinical outcome in consecutive patients with endovascular IVC reconstruction. During routine follow-up visits, stent patency was assessed by duplex ultrasound. Clinical outcomes were evaluated using the Bozkaya score, Villalta score, and revised Venous Clinical Severity Score.. Of the 62 patients (mean age, 46 ± 18 years), 33 (53%) patients were treated for the post-thrombotic syndrome, 17 (27%) for acute thrombosis, and 12 (19%) for nonthrombotic IVC occlusion. Technical success was achieved in 61 (98%) patients, with a mean of 4.5 ± 1.9 stents (iliac kissing stents in 84%). During follow-up (mean, 21 months), 22 (36%) underwent endovascular reintervention for symptomatic stent stenosis (13 [21%] with complete stent occlusion). Primary, primary assisted, and secondary patency rates at 24 months were 57% (95% confidence interval [CI], 50%-73%), 76% (95% CI, 65%-86%), and 87% (95% CI, 80%-95%), respectively. None developed new ulcers, and all eight patients with venous ulcers at baseline had complete healing. Twenty-nine (48%) patients showed significant clinical improvement, and another 26 (43%) were free from any symptoms or signs of venous hypertension. Patients with post-thrombotic venographic changes of the femoral veins at baseline or a history of thrombosis were more likely to lose primary patency compared with patients with normal leg inflow veins and no history of thrombosis (19 [48%] vs 3 [16%]; P = .02).. The clinical outcome of endovascular reconstruction of the IVC with nitinol stents was favorable. However, approximately one-third of the patients required reintervention to maintain stent patency, most likely because of the impaired venous inflow.

Topics: Adult; Aged; Alloys; Constriction, Pathologic; Endovascular Procedures; Female; Follow-Up Studies; Humans; Male; Middle Aged; Prospective Studies; Registries; Self Expandable Metallic Stents; Treatment Outcome; Ultrasonography, Doppler, Duplex; Vascular Patency; Vena Cava, Inferior; Venous Thrombosis

We tested the feasibility of local thrombolytic therapy via a novel hollow flexible and perforated wire in a mouse model of deep vein thrombosis. Inferior vena cava (IVC) thrombosis was induced by vessel wall exposure to ferric chloride after laparotomy in anesthetized C57Bl/6 mice. Thrombus formation was visualized by intravital microscopy of rhodamine-labeled platelets and leukocytes. A nitinol hypotube coronary wire with perforated tip was inserted via a 0.8 × 40 mm canula into the IVC lumen distal to the site of ferric chloride exposure. Either tissue plasminogen activator (tPA, alteplase) or saline (control) was administered via the platinum wire distal to the thrombus, avoiding mechanical fragmentation. Thrombus size was assessed by immunohistochemistry (platelet CD41 staining). Intravital microscopy of the IVC demonstrated platelet-containing thrombus growth starting 1 min after ferric chloride exposure. Alteplase administration resulted in significant thrombus size reduction within 10-20 min observed by intravital microscopy and confirmed by histological assessment of IVC cross-sections. Saline-treated mice (n = 4) demonstrated near total IVC occlusion with thrombotic material (84 ± 8% of cross-sectional area in serial sections), whereas alteplase-treated mice showed a dose-dependent decrease of thrombotic area [56 ± 5% with 1.5, 39 ± 4 % with 15 and 21 ± 6% with 150 mg/kg, respectively (n = 4)]. We demonstrate that a flexible hollow and perforated wire enables the successful application of thrombolytic therapy to IVC thrombi in mice without vessel wall perforation. Flexible wire-based thrombolytic therapy appears to be a safe and reliable method for thrombus dissolution even in fragile small veins and may become a promising strategy for targeted therapy of small vessel thrombosis.

Topics: Alloys; Animals; Disease Models, Animal; Fibrinolytic Agents; Male; Mechanical Thrombolysis; Mice; Thrombolytic Therapy; Tissue Plasminogen Activator; Venous Thrombosis

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

To investigate the use of an expanded polytetrafluoroethylene-coated nitinol stent-graft in patients with failing hemodialysis access circuits and compare grafts with and without a heparin-coated surface.. A single-institution retrospective review of 16 patients (average age, 55 years; seven men) treated for hemodialysis access circuit stenoses was performed. Patients had a prosthetic arteriovenous (AV) graft (n = 10) or autogenous AV fistula (n = 6), all with clinically relevant access stenoses that were refractory to angioplasty alone; 10 patients also had access circuit thrombosis at the time of treatment. Stents were placed in the basilic (n = 4), brachial (n = 7), cephalic (n = 4), and femoral (n = 1) veins. Study endpoints included primary treatment area patency, primary circuit patency, primary assisted circuit patency, and secondary circuit patency, followed to a maximum of 6 months.. Primary treatment area patency rates at 30 days and 180 days were 75% and 31%, respectively. Secondary patency rates at the same time points were 88% and 68%, respectively. Mean primary treatment area patency was 93 days. Thrombosis was a major cause of failure, occurring in seven of 11 cases of primary treatment area patency loss. Subgroup analysis demonstrated that the heparin-coated configuration (n = 7) showed a 6-month primary patency rate of 57%, compared with 11% for the stent-grafts without heparin bonding (n = 9; P = .06).. Overall, the majority of deployed stent-grafts lost primary patency within 6 months, with thrombosis a major cause of failure. However, the addition of a heparin-coated surface appeared to improve results in these otherwise treatment-refractory access circuits.

Topics: Adult; Aged; Alloys; Angioplasty; Anticoagulants; Arteriovenous Shunt, Surgical; Blood Vessel Prosthesis; Blood Vessel Prosthesis Implantation; Coated Materials, Biocompatible; Constriction, Pathologic; Female; Graft Occlusion, Vascular; Heparin; Humans; Kaplan-Meier Estimate; Male; Middle Aged; Polytetrafluoroethylene; Prosthesis Design; Renal Dialysis; Retrospective Studies; Secondary Prevention; Stents; Time Factors; Treatment Outcome; Vascular Patency; Venous Thrombosis

The purpose of this study is to evaluate the multimodal treatment (thrombolysis, anticoagulation and surgical decompression) of subclavian-axillary vein thrombosis (Paget-Schroetter syndrome) and possibility of shortening of time of therapy.. In this paper 23 patients with Paget-Schroetter syndrome in Department of Vascular, General and Transplantological Surgery is presented. Thrombolysis with rt-PA, anticoagulation with heparin and intra venous angioplasty with the use intravascular stent, and operation with resection of the first rib in the treatment of subclavian vein thrombosis was used. During the follow up period the patients were divided into two groups: group I (13 patients) with traditional surgical decompression after 3-4 months (potential risk of hemorage) and group II (10 patients) with early surgical treatment (median 8 days). Long-term follow-up was obtained by chart review and asking patients to complete the DASH (Disabilities of the Arm, Shoulder and Hand) questionnaire that was developed by the American Academy of Orthopedic Surgeons.. Complete revascularization with venous thrombolysis was achived in all patients. Decompresion with transaxillary resection of first rib and venous revascularization were performed in the same procedure in all patients. Statistical difference were not found in both groups. Most patients report no disability of upper limb at work and sport activity.. Multimodal treatment of Paget-Schroetter syndrome (thrombolysis, the use of intravascular stents and early thoracic outlet decompression) can be used as a optimal of therapeutic method to subclavian vein thrombosis. The advantages of immediate surgical treatment are a promotion of rapid resumption of athletic activities.

Topics: Adolescent; Adult; Alloys; Angioplasty, Balloon; Axillary Vein; Blood Vessel Prosthesis Implantation; Cervical Rib Syndrome; Decompression, Surgical; Female; Humans; Male; Phlebography; Retrospective Studies; Stents; Subclavian Vein; Syndrome; Thoracic Outlet Syndrome; Thrombolytic Therapy; Tissue Plasminogen Activator; Treatment Outcome; Venous Thrombosis

Topics: Alloys; Blood Vessel Prosthesis Implantation; Carcinoma, Hepatocellular; Follow-Up Studies; Humans; Liver Neoplasms; Male; Middle Aged; Phlebography; Prosthesis Design; Stents; Vena Cava, Inferior; Venous Thrombosis

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