Percutaneous Mechanical Thrombectomy Devices Research Articles

Initial experience with the ambulatory management of acute iliofemoral deep vein thrombosis with May-Thurner syndrome with percutaneous mechanical thrombectomy, angioplasty and stenting

ObjectivePatients undergoing intervention for acute iliofemoral deep vein thrombosis (IFDVT) with May-Thurner syndrome (MTS) typically require inpatient (IP) hospitalization for initial treatment with anticoagulation and management with pharmacomechanical thrombectomy. Direct oral anticoagulants and percutaneous mechanical thrombectomy (PMT) devices offer the opportunity for outpatient (OP) management. We describe our approach with these patients. MethodsPatients receiving intervention for acute IFDVT from January 2020 through October 2022 were retrospectively reviewed. Patients undergoing unilateral thrombectomy, venous angioplasty, and stenting for IFDVT with MTS comprised the study population and were divided into two groups: (1) patients admitted to the hospital and treated as IPs and (2) patients who underwent therapy as OPs. The two groups were compared regarding demographics, risk factors, procedural success, complications, and follow-up. ResultsA total of 92 patients were treated for IFDVT with thrombectomy, angioplasty, and stenting of whom 58 comprised the IP group and 34 the OP group. All 92 patients underwent PMT using the Inari ClotTriever (Inari Medical), intravascular ultrasound, angioplasty, and stenting with 100% technical success. Three patients in the IP group required adjuvant thrombolysis. There was no difference in primary patency of the treated IFDVT segment at 12 months between the two groups (IP, 73.5%; OP, 86.7%; P = .21, log-rank test). ConclusionsPatients with acute IFDVT and MTS deemed appropriate for thrombectomy and iliac revascularization can be managed with initiation of ambulatory direct oral anticoagulant therapy and subsequent return for ambulatory PMT, angioplasty, and stenting. This approach avoids the expense of IP care and allows for effective use of resources at a time when staffing and supply chain shortages have led to inefficiencies in the provision of IP care for nonemergent conditions.

Multimodal Approach for the Treatment of Extensive Bilateral Iliofemoral Deep Vein Thrombosis

Abstract Iliofemoral vein thrombosis is the primary cause of deep vein thrombosis (DVTs) in the lower extremities in around 25% of the cases. Restoration of venous outflow is the primary goal in the management of DVT which can be achieved by combined endovascular techniques such as balloon venoplasty and/or stenting, thrombectomy, and pharmacomechanical thrombolysis. At presently, percutaneous mechanical thrombectomy (PMT) devices, such as rheolytic thrombectomy device, are replacing conventional approaches for clot removal. Although the use of rheolytic thrombectomy device for DVT is associated with the risk of intravascular hemolysis, we report a safe and successful use of multimodal approach using rheolytic thrombolytic device for the management of a case of bilateral iliofemoral DVT. In our study, we noticed early relief in pain and reduced lower limb edema in a week with a reduced dose of thrombolytic agent and hospital stay in a 44-year-old male who was admitted with bilateral extensive iliofemoral DVT using a multimodal approach.

The paradigm shift in treatment of severe venous thromboembolism.

Pulmonary embolism (PE) is the third leading cause of cardiovascular death and the main cause of preventable in-hospital death in the world. The PERT® (Pulmonary Embolism Response Team) concept involves multidisciplinary diagnosis and immediate treatment. Deep venous thrombosis (DVT) is the initial cause of most cases of PE and is responsible for complications such as chronic thromboembolic recurrence, postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension. An aggressive approach to severe cases of iliofemoral DVT similar to the PERT® system can not only reduce the immediate risk of PE and death but can also reduce later sequelae. New percutaneous techniques and mechanical thrombectomy devices for venous thromboembolism (VTE) have shown encouraging clinical results. We propose the development of an expanded concept of rapid response to VTE, which involves not only PE (PERT®) but also severe cases of DVT: the Venous Thromboembolism Response Team (VTERT®).

Novel Percutaneous Mechanical Thrombectomy Device for Treating Upper Extremity Deep Vein Thrombosis in Patient With Paget-Schroetter Syndrome.

Paget-Schroetter Syndrome (PSS) is a form of upper extremity deep vein thrombosis (DVT) caused by the external compression of the subclavian vein at the thoracic outlet. Here we describe a complex PSS case in a 43-year-old female who experienced multiple recurrent DVTs and a right-sided hemothorax following two continuous aspiration thrombectomy procedures and a first rib resection. Rapid and complete symptom resolution was achieved with the InThrill Thrombectomy System (Inari Medical), a novel, thrombolytic-free, percutaneous mechanical thrombectomy device that removed all recurrent acute and subacute thrombus in a single session without significant blood loss.

Management of Thrombosed Dialysis Access Circuits.

Thrombotic occlusion of autologous arteriovenous fistulas or synthetic arteriovenous grafts is a serious adverse event in hemodialysis patients and declotting should be performed before next hemodialysis session, in order to avoid a central venous catheter. Various techniques exist to declot a thrombosed vascular access, including open surgical thrombectomy, catheter-directed thrombolysis and use of different types of percutaneous thrombo-aspiration catheters and mechanical thrombectomy devices. These devices can be categorized as devices with direct wall contact and hydrodynamic devices without direct wall contact. Technical and early clinical outcome results of percutaneous hemodialysis declotting are high and ranging between 70 and 100%; late clinical patency results are much lower related to restenosis or re-thrombosis; these patency results are higher for autologous arteriovenous fistulas compared to synthetic arteriovenous grafts and mainly depend on the combined efficacy of successful thrombectomy and durable treatment of the underlying stenoses, associated with the acute thrombosis.

Percutaneous mechanical thrombectomy using the Rotarex®S device for the treatment of acute lower limb artery embolism: A retrospective single-center, single-arm study.

Acute limb embolism (ALE) is a challenging, highly morbid, and frequently fatal vascular emergency. Percutaneous mechanical thrombectomy (PMT) devices are an alternative treatment to restore perfusion by removing emboli in the limb arterial system. We evaluated the outcomes of treatment of ALE patients using PMT devices in our center. A retrospective review of ALE patients treated with Rotarex S (Straub Medical) at a single institution from 2018 to 2022 was performed. The primary outcome was technical success, defined as complete recanalization of the occluded segment with satisfactory outflow and good capillary filling of the distal parts of the foot without any major or obstructing residual emboli or thrombi either in the treated segment or in the outflow tract without the need for additional catheter-directed thrombolysis (CDT) or conversion to open surgery. Embolized segments treated, treatment outcomes, and perioperative complications were reviewed. A total of 17 ALE patients (29% men, 71% women; mean age, 73 years) underwent PMT procedures. The femoral arteries and popliteal arteries are the most commonly treated vessels, with both present in 59% of the patients. The technical success rate was 100%, but the majority of cases (82%) had concurrent percutaneous transluminal angioplasty or stent grafting, and two patients were treated with urokinase during the operation. There was one thrombotic recurrence that required amputation. There were no 30-day deaths. Complications included extravasation after PMT (two), intraoperative embolization of the outflow tract (one), access site hematoma (one), target artery thrombosis (one), and acute kidney injury (one). There were no severe bleeding complications. The Rotarex S device has a satisfactory success rate, although complementary use of various adjunctive techniques is frequently required. It seems to be a moderately effective tool for treating ALE to avoid CDT or open surgery. The device appears safe, with low risks of amputation and mortality rates, but special attention should be given to the potential for extravasation and distal embolism.

Catheter-Directed Interventions for the Treatment of Lower Extremity Deep Vein Thrombosis.

Lower extremity deep vein thrombosis (DVT) leads to significant morbidity including pain, swelling, and difficulty walking in the affected limb. If left untreated, DVT increases the risk of pulmonary embolism (PE), recurrent venous thromboembolism (VTE), and post thrombotic syndrome (PTS). The objective of this review was to identify catheter-directed interventions and their success rates for the treatment of lower extremity DVT. A comprehensive search of current and emerging catheter-directed interventions for lower extremity DVT treatment was conducted in PubMed and Google Scholar. Clinical trials, retrospective and prospective observational studies, and case reports were identified to classify percutaneous mechanical thrombectomy (PMT), catheter-directed thrombolysis (CDT), and pharmacomechanical CDT (PCDT) devices based on their mechanism of action and indication of use. Catheter-directed interventions such as PMT, CDT, and PCDT offer an alternative therapeutic strategy for DVT management, particularly in patients with limb-threatening conditions and absolute contraindications to anticoagulants. Currently, there are limited guidelines for the use of mechanical and pharmacomechanical devices because of the lack of clinical evidence available for their use in treatment. Future studies are required to determine the short and long-term effects of using catheter-directed interventions as well as their effectiveness in treating acute versus subacute and chronic DVT.

Comparative Effectiveness of Current Thrombolysis and Thrombectomy Catheters for Deep Vein Thrombosis

Comparative Effectiveness of Current Thrombolysis and Thrombectomy Catheters for Deep Vein Thrombosis

Percutaneous mechanical thrombectomy device assisted TIPS recanalization: a feasibility study.

Despite improved shunt patency, transjugular intrahepatic portosystemic shunt (TIPS) occlusion remains a serious complication, and effective debulking of the existing tract is needed to restore sufficient blood flow. To evaluate the technical and clinical success of percutaneous mechanical thrombectomy in restoring patency of acutely and chronically thrombosed covered TIPS using the Aspirex®S and Rotarex®S system. We evaluated mechanical thrombectomy-assisted revisions in five patients between January 2012 and April 2021. Two patients had to be revised twice due to recurrent occlusion. We designated thrombosis within 10 days after shunt creation or revision as acute. Insidious deterioration of portal hypertension related symptoms for at least 6-8 weeks was recorded in chronic cases. We treated four acute and three chronic occlusions. After transjugular lesion crossing, we performed two mechanical thrombectomy device passages. If indicated, balloon dilatation, covered stent placement, or variceal embolization were added. The technical success rate was 100%. No procedure-related complications occurred. In one patient with acute decompensation of Budd-Chiari syndrome and acute-on-chronic liver failure, early re-thrombosis occurred twice with patency intervals of up to eight days. In contrast, stable patency was achieved in the other four patients with documented patency intervals of at least five months and improvement of portal hypertension-related symptoms, resulting in a patient based clinical success rate of 80%. In five patients, percutaneous mechanical thrombectomy assisted TIPS recanalization of four acute and three chronic occlusions proved to be technically feasible and safe with a high clinical success rate.

Outcome of catheter directed thrombolysis for popliteal or infrapopliteal acute arterial occlusion.

Management of acute limb ischemia (ALI) due to occlusions in popliteal and infrapopliteal arteries remains a challenge. Open surgical methods and even the novel percutaneous mechanical thrombectomy devices have not shown satisfactory results in these small arteries. The aim of this prospective study was to assess the safety and efficacy of catheter-directed thrombolysis (CDT) in this type of ALI with distal occlusion. Between April 2017 and June 2019, 22 patients with ALI secondary to popliteal or infrapopliteal occlusion were enrolled in the study. Patients with thrombosis, embolism, and thrombosed bypass graft were included; all belong to category I or IIa of Rutherford's classification. Technical success, limb salvage, complications, and mortality were evaluated at short- and long-term follow-up. Technical success was achieved in 81.8%, while 36.4% of patients needed additional balloon angioplasty, major amputation in 13.6%, minor bleeding in 18.2%, andno major hemorrhage. Limb salvage at 30days and 1year was 86.4% and 72.7%, respectively. At 1year, primary patency was 63.6% and mortality was 9.1%. Catheter directed thrombolysis is a safe and highly effective treatment modality for popliteal or infrapopliteal acute limb ischemia unless contraindicated.

Technical success and short-term outcomes after treatment of lower extremity deep vein thrombosis with the ClotTriever system: A preliminary experience

BackgroundDeep vein thrombosis (DVT) may be associated with significant pain, swelling and the development of post-thrombotic syndrome. Early clot removal is facilitated by the use of percutaneous mechanical thrombectomy devices. Current techniques, however, vary in rates of technical success and in some cases are limited by the concomitant need for thrombolytics. An alternative percutaneous venous thrombectomy system (ClotTriever, Inari Medical, Irvine, Calif) may be helpful in the management of lower extremity DVT without the concomitant use of thrombolytics. MethodsA retrospective review of patients treated for DVT using the device was conducted. Demographics, initial presentation, and perioperative course were recorded. Outcomes after treatment were extracted from clinical records. Technical success was defined as complete clot evacuation after intervention. ResultsTwelve patients were included in the study. The cohort was 50% female (6 patients) with a mean age of 55.6 years (range, 32-86 years). Two patients (16.7%) presented with chronic asymptomatic DVT who developed symptoms from an acute, recurrent iliofemoral DVT over the days before presentation. One patient (8.4%) presented with phlegmasia cerulea dolens, with the remaining patients presenting with disabling pain and swelling. Access was obtained via the popliteal vein (11 patients) and small saphenous vein (1 patient). Lytic therapy was not used in any case. Complete clot evacuation was obtained in all patients in a single session without repeat interventions. Symptom resolution before discharge was achieved in 100% of cases. There was no incidence of postoperative anemia (mean hemoglobin, 10.7 g/dL preoperatively vs 10.4 g/dL postoperatively) or acute kidney failure (mean creatinine, 0.86 mg/dL preoperatively vs 0.81 mg/dL postoperatively). The average length of stay was 2 days (range, 1-4 days) without the need for intensive care admission. At early follow-up, 11 patients (91.7%) continued to report significant symptom resolution. Two of 10 patients (20%) developed recurrent occlusive DVTs on follow-up duplex ultrasound examination. ConclusionsThis novel percutaneous venous thrombectomy system is safe and effective for removing large volumes of lower extremity acute thrombus in a single session, without the need for lytic therapy, intensive care unit admission, or repeat intervention. Further studies are warranted to determine mid-term and long-term outcomes.

Comparison of ASPIRE Mechanical Thrombectomy Versus AngioJet Thrombectomy System in a Porcine Iliac Vein Thrombosis Model

Percutaneous mechanical thrombectomy device has become an important therapeutic armamentarium in the management of venous thromboembolism. In this study, we compare the efficacy and safety profile of the AngioJet thrombectomy device and ASPIRE thrombectomy system in a porcine venous thrombosis model. Twelve adult pigs underwent bilateral iliac venous thrombosis created by using a stent graft thrombosis model and subsequently underwent either AngioJet (n=6) or ASPIRE mechanical thrombectomy (n=6) 1 week later. Intravascular ultrasound (IVUS) was used to assess thrombectomy efficacy, and computed tomography was used to evaluate pulmonary embolism (PE). Hemolytic effect was measured by plasma-free hemoglobin (PfHgb). Iliac vein thrombogenicity was evaluated with radiolabeled platelet and fibrin deposition. Veins were harvested and evaluated with light microscopy and scanning electron microscopy (SEM). Similar thrombectomy efficacy by IVUS evaluation was noted in both groups. Significant greater PE and hemolysis were identified in the AngioJet group compared to the ASPIRE group. The AngioJet group had greater reduction in WBC and platelet compared to the ASPIRE group. No difference was found in thrombogenicity, light microscopic evaluation, or SEM. Both devices had similar thrombectomy efficacy and thrombogenicity response. The ASPIRE catheter incurred less PE and hemolysis compared to the AngioJet device. Vessel wall response by histological analysis and SEM was similar in both groups.

Aspirex Thrombectomy in Occluded Dialysis Access: A Retrospective Study.

This study is the first to present the outcomes of the Straub Aspirex device for the salvage of occluded renal dialysis access fistulae. This is a retrospective study, using data from the Renal Unit and Radiology Department database. It included all the patients between 2010 and 2014 who underwent percutaneous mechanical thrombectomy (PMT) treated by JD. Aspirex is an over-the-wire, 6-10 French catheter within which is a rapidly rotating helix which draws thrombus into a window near the tip which it then macerates and removes. Access survival was assessed using the Kaplan-Meier method, and multi-variant analysis was performed using the Cox proportional hazards model. Significance was considered if p<0.05. A total of 27 procedures were performed for 19 patients. 13 had autologous arterio-venous fistulae, and 14 had synthetic (PTFE) arterio-venous grafts. 15 were males, 4 females. 100% of the patients successfully had a channel of thrombus removed. This resulted in an 81.5% initial clinical success, with primary patency rates of 53.6, 44.3 and 33% by days 30, 90 and 480, respectively, without significant difference of any analysed covariates. No major complication (pulmonary embolus, paradoxical cerebral infarction, limb ischaemia or significant haemorrhage) occurred. Aspirex has rates of patency and complication similar to other PMT devices. No covariant studied affected outcome.

Current and future prospects of endovascular treatment for acute ischemic stroke

Recently, remarkable progress has been made in the field of endovascular treatment, and endovascular treatment for acute ischemic stroke due to large vessel occlusion has been an effective and therapeutic option. However, there is no randomized control trial as to superiority of endovascular treatment for acute ischemic stroke compared to the standard treatment including intravenous rt-PA. Inclusion criteria for the performance of endovascular treatment for acute ischemic stroke will need to be defined more precisely, and high rates of fast recanalization will be needed in future. We expect the evidence that endovascular treatment for acute ischemic stroke due to large vessel occlusion is superior to standard treatment by the detailed images of the brain, more strict indications and novel endovascular devices such as percutaneous transluminal mechanical thrombectomy devices.

Management of proximal deep vein thrombosis

Iliofemoral DVT constitutes approximately 20-25% of lower limb DVT and represents a specific subgroup of patients at highest risk for post-thrombotic syndrome (PTS). Anticoagulation alone has no significant thrombolytic activity and has not impact on PTS prevention. Early thrombus removal has reduced PTS in uncontrolled reports and reviews but major trials are awaited. The optimal timing for treatment appear to be thrombus <2 weeks old and, methods for thrombus removal include direct open or suction thrombectomy, catheter directed thrombolysis (CDT), with or without percutaneous mechanical thrombectomy (PMT) devices. Three principle types of PMT device are in use (rotational, rheolytic and ultrasound enhanced devices) and are combined with CDT in pharmocomechanical thrombolysis (PhMT) to enhance early thrombus removal. These devices have individual device specific attributes and side effects that are additional to the bleeding complications of thrombolysis. A number of additional interventions may be utilised to the improve results of CDT and PhMT. IVC filter deployment to reduce periprocedural PE, is supported by little evidence unless an indication for its use already exists. However, balloon venoplasty and vein stents undoubtedly vein patency after treatment. Early thrombus removal comes with additional upfront costs derived from devices, imaging and critical care bed usage. However, significant potential savings from reduction in PTS and rethrombosis rates may reduce overall societal costs. This review focuses on iliofemoral thrombosis, however, the less commonly encountered but clinically important subclavian vein thrombosis is also discussed.

A Systematic Review of Percutaneous Mechanical Thrombectomy in the Treatment of Deep Venous Thrombosis

Background: In selected cases of deep vein thrombosis (DVT), catheter-directed thrombolysis (CDT) may be superior to conventional treatment with anticoagulation alone, as it can prevent DVT recurrence and the development of post-thrombotic syndrome (PTS). Percutaneous mechanical thrombectomy (PMT) devices offer a minimally invasive adjunctive strategy and the data on these emerging technologies require review. Objectives: To review the evidence for PMT devices in DVT in terms of case selection, technical feasibility and procedural outcomes. Methods: Medline, trial registries, conference proceedings and article reference lists were searched to identify case series reporting PMT device use. Data were extracted for review. Results: 16 retrospective case series have reported the use of rheolytic, rotational, or ultrasound-assisted PMT in a total of 481 patients. No randomised trials were available. Technical success of 82–100% was reported with Grade II or III lysis in 83–100% of patients. The different devices all appeared to be safe, with no reported procedure-related deaths or strokes and <1% incidence of symptomatic PE. Bleeding complications were reported in 6/16 studies, in which 4–14% of patients required transfusion (global incidence 11/146 patients, 7.5%). Conclusion: PMT appears feasible and safe, though the level of evidence available is poor. Major RCTs and registry data are required to determine the economic and clinical benefit of various devices used alone or in combination, for differing thrombus characteristics and clinical scenarios. Until these data are available there is little substantial evidence to support the routine use of PMT over CDT alone.

Invited commentary

The publication of a randomized controlled trial in the vascular arena is rare. The publication of a trial with negative results is rarer. Han and colleagues should be applauded for an honest portrayal of the use of alfimeprase in the setting of acute limb ischemia (ALI). Alfimeprase, a novel recombinant variant of fibrolase, displayed promising results in preclinical and pilot studies. In contrast to available thrombolytic agents, alfimeprase is a direct fibrinolytic enzyme and has no effect on plasminogen. In addition, any drug that escapes into the general circulation is quickly degraded by α2-macroglobulin which is ubiquitous in plasma. These properties have the potential to overcome limitations that exist with current therapies: the duration of therapy and the risk of bleeding. A rapidly-acting, direct fibrinolytic without systemic plasminogen activation and plasma neutralization seem like ideal characteristics for a thrombolytic agent. In this report, data from two essentially blinded, placebo-controlled, randomized controlled trials evaluating alfimeprase for ALI are reported. Alas, alfimeprase showed no greater effectiveness than placebo in ALI patients with mostly femoral/popliteal thrombus in native arteries. In fact, the rates of distal embolization and amputation in the treatment groups were troubling. Trial design is a critical component in the analyses of any pharmaceutical agent. The primary endpoint of “avoidance of open vascular surgery at 30 days” may not be a realistic endpoint in patients with ALI. Thrombolysis may be the only therapy required for patients with an embolus in an otherwise normal arterial tree. However, most patients reported in these trials developed ALI from thrombosis in the setting of extensive atherosclerotic occlusive disease. The dissolution of thrombus uncovers a culprit lesion which may require a limited surgical procedure for durable patency. Time to patency, cost, resource utilization, and grading of the extent of open surgery are surrogate endpoints that can be used for ALI trials and would likely favor alfimeprase in future studies. Amputation-free survival is perhaps the best global endpoint, but one that requires a large sample size. The inclusion of a placebo group is difficult since acceptable results are obtained with thrombolysis in patients that are often ill-prepared to withstand major limb revascularization. In fact, the surprising “effectiveness” of intrathrombus placebo leads to the alternative conclusion that percutaneous mechanical thrombectomy devices utilizing rheolysis may be clinically beneficial in most cases of ALI. The compelling preclinical data on alfimeprase did not translate into clinical efficacy. Enhanced dosing and delivery strategies may salvage alfimeprase. I agree with the authors that further study is warranted. Efficacy and safety of alfimeprase in patients with acute peripheral arterial occlusion (PAO)Journal of Vascular SurgeryVol. 51Issue 3PreviewTo investigate the safety and effectiveness of a novel thrombolytic, alfimeprase, in catheter-directed thrombolysis (CDT) of acute peripheral arterial occlusions (PAO). Full-Text PDF Open Archive

Abstract No. 263 EE: Portomesenteric thrombosis: Multiple approaches to percutaneous access and techniques for transcatheter treatment

Understand the disease entity portomesenteric thrombosis, its major underlying contributing factors, treatment options and interventional radiology's unique place within this spectrum. Understand specific techniques on how to successfully access the portomesenteric venous system for subsequent transcatheter therapy utilizing different approaches and imaging modalities through case examples. Understand the wide scope of specific percutaneous transcatheter treatment options through case examples. Portomesenteric venous thrombosis (PVT) is rare but potentially devastating condition accounting for 5% to 15% of all mesenteric ischemic events. This disease process includes a spectrum of clinical presentations ranging from incidental findings in an asymptomatic patient to fulminate liver failure and life-threatening bowel infarction with reported mortality rates of 13-50% for mesenteric thrombosis. Current therapy options for PVT involves a spectrum ranging from anticoagulation to invasive surgery including multivisceral transplantation in extreme cases. In recent years modern imaging guidance and catheter directed techniques have allowed percutaneous intervention to become an important treatment option for many patients. Cases will be highlighted demonstrating portomesenteric access from the transhepatic and bilateral transjugular routes as well as direct cannulation of the mesenteric vein during laparotomy. Examples of transhepatic access will be further divided by imaging modality including percutaneous puncture under fluoroscopy, ultrasound, and CT guidance. Examples of different transcatheter treatment options will include passive instillation of thrombolytics, pulse spray thrombolysis, use of pharmaco-mechanical combination as well as percutaneous mechanical thrombectomy devices such as Trellis-8 and AngioJet. Interventional radiology has a key role in administering effective, focused, minimally invasive treatment for the rare but potentially devastating disease entity of portomesenteric thrombosis by incorporating a spectrum of percutaneous options utilizing multiple approaches and treatment delivery techniques which can be tailored to specific patients needs.

Endovascular Treatment Options in the Management of Lower Limb Deep Venous Thrombosis

Lower limb deep vein thrombosis (DVT) is a common cause of significant morbidity and mortality. Systemic anticoagulation therapy is the mainstay of conventional treatment instituted by most physicians for the management of DVT. This has proven efficacy in the prevention of thrombus extension and reduction in the incidence of pulmonary embolism and rethrombosis. Unfortunately, especially in patients with severe and extensive iliofemoral DVT, standard treatment may not be entirely adequate. This is because a considerable proportion of these patients eventually develops postthrombotic syndrome. This is characterized by chronic extremity pain and trophic skin changes, edema, ulceration, and venous claudication. Recent interest in endovascular technologies has led to the development of an assortment of minimally invasive, catheter-based strategies to deal with venous thrombus. These comprise catheter-directed thrombolysis, percutaneous mechanical thrombectomy devices, adjuvant venous angioplasty and stenting, and inferior vena cava filters. This article reviews these technologies and discusses their current role as percutaneous treatment strategies for venous thrombotic conditions.

Do Randomized Trials of Thrombolysis Versus Open Revascularization Still Apply to Current Management: What Has Changed?

Several randomized trials of catheter-directed thrombolysis versus operative revascularization in patients with acute lower extremity ischemia were performed in the mid-1990 s. Although the outcomes of these trials were not definitive, they did provide insight into potential uses and techniques of catheter-directed thrombolysis and lytic agents. This article reviews the outcomes of these randomized trials and describes advances in thrombolytic techniques and technology, including percutaneous mechanical thrombectomy devices and innovative catheter designs that accelerate lysis and the development of direct-acting lytic agents.