Catheter Directed Thrombolysis for Treatment of Ilio-femoral Deep Venous Thrombosis is Durable, Preserves Venous Valve Function and May Prevent Chronic Venous Insufficiency

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

OBJECTIVE

Patients 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.

METHODS

Patients 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.

RESULTS

A 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).

CONCLUSIONS

Patients 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.

Anatomical consideration of deep calf veins: application to catheter-directed thrombolysis

Purpose

An antegrade approach is frequently used in catheter-directed thrombolysis to remove deep-vein thrombosis. However, the antegrade approach is difficult when accessing veins with small diameters; therefore, understanding the variation of deep calf vein is important.

Methods

This study measured the diameters and surface areas of the proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein to determine which are preferable for venous access. This study dissected 132 legs from Korean and Thai cadavers. The proximal and distal posterior tibial vein, peroneal vein, and anterior tibial vein were scanned and measured.

Results

The mean diameter and surface area were largest for the proximal tibial vein, at 6.34 mm and 0.312 cm², respectively, followed by the anterior tibial vein (5.22 mm and 0.213 cm²), distal posterior tibial vein (3.29 mm and 0.091 cm²), and peroneal vein (3.43 mm and 0.081 cm²). The proximal posterior tibial vein and anterior tibial vein have large diameters and surface areas, which make them ideal for applying an antegrade approach in catheter-directed thrombolysis.

Conclusions

The distal posterior tibial vein and peroneal vein are not recommended due to their smaller surface areas and also the anatomical variations therein.

Postinterventional antithrombotic management after venous stenting of the iliofemoral tract in acute and chronic thrombosis: A systematic review

Venous stenting has become a common treatment option for central deep venous outflow obstructions and postthrombotic syndrome. Following successful recanalization and stenting, stent patency is endangered by in-stent thrombosis and recurrent venous thromboembolism. Antithrombotic therapy might reduce patency loss. This systematic review summarizes the literature on antithrombotic therapy following (post)thrombotic venous stenting. A systematic PubMed, MEDLINE, EMBASE, and Cochrane search was performed for studies addressing antithrombotic therapy prescribed following venous stenting of the iliofemoral tract indicated by acute or chronic thrombotic pathology. A total of 277 articles was identified of which 64 (56 original studies) were selected. Overall, a mean primary patency rate of 82.3% was seen 1 year after the intervention, which decreased to 73.3% after 2 years. In the majority (43 of 56 studies, 77%), treatment was based on use of vitamin K antagonists, either with (18%) or without (59%) use of antiplatelet drugs. Only two studies (4%) directly assessed the effect of antithrombotic therapy on treatment outcomes. The impact of postinterventional antithrombotic therapy on stent patency remains unknown because of limited and insufficient data available in current literature. Further clinical research should more clearly address the role of antithrombotic therapy for preservation of long-term patency following venous stenting.

Is variation in posterior tibial veins a risk factor for deep-vein thrombosis?

INTRODUCTION

This study proposes variations in the posterior tibial vein as one of the risk factors for deep-vein thrombosis. Understanding the anatomical classification of the posterior tibial vein would guide the antegrade approach of catheter-directed thrombolysis.

MATERIALS AND METHODS

One hundred thirty-four legs from Korean and Thai cadavers were dissected. The posterior tibial veins were classified into four types according to the number of proximal and distal veins.

RESULTS

The most common type was type Ia (64/134), followed by type IIa (28/134), type Ib (24/134), and type IIb (16/134).

CONCLUSIONS

The anterior tibial and fibular veins had exactly two paired veins; however, the posterior tibial vein had many variations. We assume that patients with type IIb and IIa have a higher risk of thrombosis and hidden symptoms due to collateral formation. Additionally, the classification of the posterior tibial vein and dividing into proximal and distal posterior tibial vein would help practitioners predict the course and guide the application of catheter-directed thrombolysis.

Targeted gene expression analysis of human deep veins

OBJECTIVE

Endothelial-derived molecules involved in thrombosis and hemostasis have been investigated mainly in arteries and in experimental animals. The actual presence and integral function of these molecules in the human deep venous system have received less attention. Our aim was to evaluate the expression of certain prothrombotic and antithrombotic genes in the normal human deep veins of the lower extremities.

METHODS

Macroscopically intact and competent valve-containing segments of human deep veins were prospectively collected from patients who had undergone above-knee amputation. Vein samples were separated into four zones: zone 1, postvalve (downstream, proximal) vein wall; zone 2, the valve cusp; zone 3, prevalve (upstream, distal) vein wall; and zone 4, vein wall within the valve cusp (cusp removed). Real-time quantitative polymerase chain reaction for principal genes involved in coagulation, fibrinolysis, and inflammation was performed to quantify messenger RNA. Selected protein gene products were measured by the western blot assay. One additional valve-containing segment underwent mass spectrometry analysis to investigate global differences in the proteome between the study zones.

RESULTS

Seventeen valve-containing vein segments were analyzed. Significant upregulation of antithrombotic (protein C receptor [PROCR], thrombomodulin [THBD], tissue factor pathway inhibitor [TFPI]), prothrombotic (con Willebrand factor [VWF]), and proinflammatory (selectin P [SELP], intercellular adhesion molecule 1 [ICAM1]) genes was found in the valve cusp compared with the vein wall (P < .05). PROCR and THBD demonstrated the highest level of upregulation in the valve cusp. PROCR, serpin peptidase inhibitor, clade E, member 1 (SERPINE1), and SELP were upregulated in the valve cusp at the protein level (P < .05). Messenger RNA composition in the vein wall within the valve cusp was similar to the prevalve and postvalve vein wall for all genes, except for two times overexpressed ICAM1 (P < .05). Substantial differences within the proteome between the study zones were observed with mass spectrometry.

CONCLUSIONS

The biological properties of the valve cusp, vein wall within the valve cusp, and vein wall beyond the valve cusp are different. The endothelium of the valve cusps of a normal competent deep venous valve may be naturally less thrombogenic compared with the vein wall. The endothelium of the valve cusp may have a higher potential to interact with white blood cells compared with the vein wall. Mass spectrometry demonstrates substantial differences in the proteome between the vein wall and the valve cusps that were not anticipated before. (J Vasc Surg Venous Lymphat Disord 2021;9:770-80.) CLINICAL RELEVANCE: Deep vein thrombosis (DVT) is a major cause of mortality, morbidity, and impaired quality of life. Multiple risk factors have been identified, although their relative weight and pathophysiologic interactions remain obscure. Many patients with multiple risk factors for DVT never develop this condition. Conversely, in numerous cases DVT cannot be attributed to any known clinical risk factor. The molecular mechanisms that initiate DVT are unclear. An improved understanding of the normal biology of human deep veins will serve as an important foundation for new hypotheses of the pathogenesis of DVT. The latter may suggest new projects on novel therapeutic strategies.

Relationships between the use of pharmacomechanical catheter-directed thrombolysis, sonographic findings, and clinical outcomes in patients with acute proximal DVT: Results from the ATTRACT Multicenter Randomized Trial

Few studies have documented relationships between endovascular therapy, duplex ultrasonography (DUS), post-thrombotic syndrome (PTS), and quality of life (QOL). The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial randomized 692 patients with acute proximal deep vein thrombosis (DVT) to receive anticoagulation or anticoagulation plus pharmacomechanical catheter-directed thrombolysis (PCDT). Compression DUS was obtained at baseline, 1 month and 12 months. Reflux DUS was obtained at 12 months in a subset of 126 patients. Clinical outcomes were collected over 24 months. At 1 month, patients who received PCDT had less residual thrombus compared to Control patients, evidenced by non-compressible common femoral vein (CFV) (21% vs 35%, p < 0.0001), femoral vein (51% vs 70%, p < 0.0001), and popliteal vein (61% vs 74%, p < 0.0001). At 12 months, in the ultrasound substudy, valvular reflux prevalence was similar between groups (85% vs 91%, p = 0.35). CFV non-compressibility at 1 month was associated with higher rates of any PTS (61% vs 46%, p < 0.001), a higher incidence of moderate-or-severe PTS (30% vs 19%, p = 0.003), and worse QOL (difference 8.2 VEINES-QOL (VEnous INsufficiency Epidemiological and Economic Study on Quality of Life) points; p = 0.004) at 24 months. Valvular reflux at 12 months was associated with moderate-or-severe PTS at 24 months (30% vs 0%, p = 0.01). In summary, PCDT results in less residual thrombus but does not reduce venous valvular reflux. CFV non-compressibility at 1 month is associated with more PTS, more severe PTS, and worse QOL at 24 months. Valvular reflux may predispose to moderate-or-severe PTS. ClinicalTrials.gov Identifier NCT00790335.

Cessation of anticoagulation therapy following endovascular thrombus removal and stent placement for acute iliofemoral deep vein thrombosis

Summary. Background: The optimal duration of anticoagulation therapy (AT) following catheter-based therapy of acute iliofemoral deep vein thrombosis (IFDVT) with stent placement is unknown. Theoretically, resolving the underlying obstructive iliac vein lesion by a stent may eliminate the main trigger for recurrence, the post-thrombotic syndrome (PTS), and the need for extended-duration AT. Patients and methods: From 113 patients with acute IFDVT who underwent endovascular thrombus removal and stent placement, we compared patency rates and clinical outcomes between 58 patients on limited-duration AT (3–12 month) and 55 patients on extended-duration AT (> 12 months). Results: Mean follow-up duration was 26 ± 18 (range 3–77) months; it was 24 ± 18 (range 3–69) months after cessation of AT in the limited-duration AT group. In comparison to patients with extended-duration AT, patients with limited-duration AT were younger (38 versus 54 years; p < 0.001), more often female (74 % versus 49 %; p = 0.01), and had less often prior venous thromboembolism (VTE) (9 % versus 35 %; p = 0.001). May-Thurner syndrome was more frequent in the limited-duration AT group (66 % versus 38 %; p = 0.004). Overall, primary and secondary patency rates at 24 months were 80 % (95 % CI, 70–87 %) and 95 % (95 % CI, 88–98 %), respectively, with no difference between the groups. Overall, 17 (15 %) patients developed recurrent VTE, of which 14 (82 %) events were thrombotic stent occlusions, and 13 (76 %) events occurred during AT. In the limited-duration AT group, 98 % patients were free from the PTS at two years with a VTE recurrence rate of 3.5 per 100 patient years after cessation of AT. Conclusions: In selected patients with acute IFDVT and patent venous stent, particularly in younger and otherwise healthy patients with May-Thurner syndrome, it appears to be safe to discontinue AT 3–12 months after endovascular treatment. Clinical Trial Registration: The study is registered on the National Institutes of Health website (ClinicalTrials.gov; identifier NCT02433054).

Rivaroxaban or vitamin-K antagonists following early endovascular thrombus removal and stent placement for acute iliofemoral deep vein thrombosis

BACKGROUND

The optimal anticoagulant following catheter-based therapy of acute iliofemoral deep vein thrombosis (IFDVT) is unknown.

METHODS

From the Swiss Venous Stent registry, an ongoing prospective cohort study, we performed a subgroup analysis of patients with acute IFDVT who underwent catheter-based early thrombus removal followed by nitinol stent placement. Duplex ultrasound and Villalta scores were used to determine patency rates and incidence of the post-thrombotic syndrome (PTS) in patients treated with either rivaroxaban (n = 73) or a vitamin K-antagonist (VKA; n = 38) for a minimum duration of 3 months.

RESULTS

Mean follow-up duration was 24 ± 19 months (range 3 to 77 months). Anticoagulation therapy was time-limited (3 to 12 months) in 56% of patients (47% in the rivaroxaban group and 58% in the VKA group, p = 0.26), with shorter mean duration of anticoagulation in the rivaroxaban group (180 ± 98 days versus 284 ± 199 days, p = 0.01). Overall, primary and secondary patency rates at 24 months were 82% (95%CI, 71-89%) and 95% (95%CI, 87-98%), respectively, with no difference between the rivaroxaban (87% [95%CI, 76-94%] and 95% [95%CI, 85-98%]) and the VKA group (72% [95%CI, 52-86%] and 94% [95%CI, 78-99%]; p > 0.10 for both). Overall, 86 (86%) patients were free from PTS at latest follow-up, with no difference between the rivaroxaban and the VKA groups (57 [85%] versus 29 [88%]; p = 0.76). Two major bleeding complications (1 in each group) occurred in the peri-interventional period, without any major bleeding thereafter.

CONCLUSIONS

In patients with acute IFDVT treated with catheter-based early thrombus removal and venous stent placement, the effectiveness and safety of rivaroxaban and VKA appear to be similar.

CLINICAL TRIAL REGISTRATION

The study is registered on the National Institutes of Health website (ClinicalTrials.gov; identifier NCT02433054).

Catheter-directed thrombolysis through anterior tibial vein for treating acute extensive deep venous thrombosis

OBJECTIVE

The objective of this study was to evaluate the feasibility, efficacy, and safety of catheter-directed thrombolysis (CDT) through an anterior tibial vein approach for acute extensive lower extremity deep venous thrombosis (DVT).

METHODS

There were 125 consecutive patients with acute extensive lower extremity DVT who received CDT through an anterior tibial vein approach between October 2014 and June 2017. The patients with iliac vein compression syndrome were treated with balloon dilation and stent implantation after CDT. The thrombus score differences, limb circumference differences, venous patency, and complications were retrospectively analyzed.

RESULTS

The anterior tibial vein approach was successfully achieved in 118 patients (94.40% [118/125]). The mean thrombolysis time was 5.28 ± 1.10 days, and the average dose of urokinase was 3,903,400 ± 766,900 IU. Metal stents were placed in 50 patients (42.37% [50/118]). There were 109 patients (92.37% [109/118]) who had successful lysis (grade II and grade III lysis); 31 patients (91.18% [31/34]) achieved grade III lysis (no residual thrombus) within 3 days of symptom onset. In contrast, only 33.96% (18/53) of those treated within 4 to 7 days and 9.68% (3/31) of those treated after 7 days achieved grade III lysis. Compared with findings before CDT, the limb circumference above and below the knee was significantly reduced (7.22 ± 2.54 cm vs 1.58 ± 0.75 cm and 5.14 ± 1.41 cm vs 1.19 ± 0.49 cm, respectively). The incidence of bleeding was 10.17% (12/118). Six patients had puncture site bleeding, and three patients suffered major bleeding. One puncture site infection and two catheter-directed infections were observed during treatment. Two patients had accidental anterior tibial artery injury and recovered without complications, and no nerve injury occurred. During a follow-up of 19.39 ± 7.47 months (6-32 months), femoral venous insufficiency and popliteal venous insufficiency were present in 21.65% (21/97) and 30.93% (30/97) of the patients. The overall patency and post-thrombotic syndrome rates were 83.51% (81/97) and 21.65% (21/97).

CONCLUSIONS

CDT through an anterior tibial vein approach is a feasible, effective, and safe method for acute extensive lower extremity DVT patients. In addition, the anterior tibial vein approach can be an alternative to the traditional CDT approach.

Catheter-directed thrombolysis for patients with acute lower extremity deep vein thrombosis: a meta-analysis

Objectives:

To evaluate case series studies that quantitatively assess the effects of catheter-directed thrombolysis (CDT) and compare the efficacy of CDT and anticoagulation in patients with acute lower extremity deep vein thrombosis (DVT).

Methods:

Relevant databases, including PubMed, Embase, Cochrane, Ovid MEDLINE and Scopus, were searched through January 2017. The inclusion criteria were applied to select patients with acute lower extremity DVT treated with CDT or with anticoagulation. In the case series studies, the pooled estimates of efficacy outcomes for patency rate, complete lysis, rethrombosis and post-thrombotic syndrome (PTS) were calculated across the studies. In studies comparing CDT with anticoagulation, summary odds ratios (ORs) were calculated.

Results:

Twenty-five articles (six comparing CDT with anticoagulation and 19 case series) including 2254 patients met the eligibility criteria. In the case series studies, the pooled results were a patency rate of 0.87 (95% CI: 0.85-0.89), complete lysis 0.58 (95% CI: 0.40-0.75), rethrombosis 0.11 (95% CI: 0.06-0.17) and PTS 0.10 (95% CI: 0.08-0.12). Six studies comparing the efficacy outcomes of CDT and anticoagulation showed that CDT was associated with a reduction of PTS (OR 0.38, 95%CI 0.26-0.55, p<0.0001) and a higher patency rate (OR 4.76, 95%CI 2.14-10.56, p<0.0001).

Conclusion:

Acute lower extremity DVT patients receiving CDT were found to have a lower incidence of PTS and a higher incidence of patency rate. In our meta-analysis, CDT is shown to be an effective treatment for acute lower extremity DVT patients.

A systematic review on the use of deep venous stenting for acute venous thrombosis of the lower limb

OBJECTIVES

The aim is to evaluate venous stent patency, the development of post-thrombotic syndrome, recurrence, quality of life and the optimal post-procedural anticoagulation regimen in the treatment of iliofemoral deep venous thrombosis.

METHOD AND RESULTS

EMBASE and Medline databases were interrogated to identify studies in which acute deep venous thrombosis patients were stented. Twenty-seven studies and 542 patients were identified. Primary, assisted primary and secondary patency rates 12 months after stent placement ranged from 74 to 95, 90 to 95 and 84 to 100%, respectively. The observed post-thrombotic syndrome rate was 14.6%. The incidence of stent re-thrombosis was 8%. In 26% of studies, patients received additional antiplatelet therapy. Quality of life questionnaires employed in 11% of studies, demonstrating an improvement in the chronic venous insufficiency questionnaire (22.67 ± 3.01 versus 39.34 ± 6.66).

CONCLUSION

Venous stenting appears to be an effective adjunct to early thrombus removal; however, further studies are needed to identify optimal anticoagulant regimen and effect on quality of life.

Safety and Efficacy of Catheter Direct Thrombolysis in Management of Acute Iliofemoral Deep Vein Thrombosis: A Systematic Review

Purpose

Catheter direct thrombolysis (CDT) has been shown to be an effective treatment for deep venous thrombosis. The objective of the review is to improve safety and efficacy of the CDT by using ward based protocol, better able to predict complications and treatment outcome through monitoring of haemostatic parameters and clinical observation during thrombolysis procedure.

Materials and Methods

MEDLINE, EMBASE, CENTRAL and Web of Science were searched for all articles on deep venous thrombosis, thrombolysis and correlations of clinical events (bleeding, successful thrombolysis) during thrombolysis with hemostatic parameters to March 2016. The risk of bias in included studies was assessed by Cochrane Collaboration’s tool and Cochrane Risk of Bias Assessment Tool: for Non-Randomized Studies of Interventions.

Results

Twenty-four studies were included in the review and we found that improving safety and efficacy of CDT by using ward based protocol depending on eight factors; strict patient selection criteria, types of fibrinolytic drugs, mode of fibrinolytic drug injection, biochemical markers monitoring (fibrinogen, D-dimer, activated partial thromboplastin time, plasminogen activator inhibitor-1), timing of intervention, usage of intermittent pneumatic calf, ward monitoring and thrombolysis imaging assessment (intravascular ultrasound). These factors may help to improve safety and efficacy by reducing total thrombolytic drug dosage and at the same time ensure successful lysis. There is a marked lack of randomized controlled trials discussing the safety and efficacy of catheter direct thrombolysis.

Conclusion

CDT can be performed safely and efficiently in clinical ward, providing that careful nursing, biochemical monitoring, proper selection and mode of infusion of fibrinolytic drugs, usage of Intermittent pneumatic calf and adequate thrombolysis imaging assessment are ensured.

Safety of catheter-directed thrombolysis for the treatment of acute lower extremity deep vein thrombosis: A systematic review and meta-analysis

BACKGROUND

Despite established guidelines, catheter-directed thrombolysis (CDT) for the management of acute lower extremity deep vein thrombosis (DVT) should not be overstated because the risks of CDT are uncertain. We performed a meta-analysis to comprehensively and quantitatively evaluate the safety of CDT for patients with acute lower extremity DVT.

METHODS

Relevant databases, including PubMed, Embase, Cochrane, Ovid MEDLINE, and Scopus, were searched up to January 2017. The inclusion criteria were applied to select patients with acute lower extremity DVT treated by CDT or compared CDT with anticoagulation. In case series studies, the pooled estimates of safety outcomes for complications, pulmonary embolism (PE), and mortality were calculated across studies. In studies comparing CDT with anticoagulation, summary odds ratios (ORs) were calculated.

RESULTS

Of the 1696 citations identified, 24 studies (6 comparing CDT with anticoagulation and 18 case series) including 9157 patients met the eligibility criteria. In the case series studies, the pooled risks of major, minor, and total complications were 0.03 (95% confidence interval [CI]: 0.02-0.04), 0.07 (95% CI: 0.05-0.08), and 0.09 (95% CI: 0.08-0.11), respectively; other pooled risk results were 0.00 for PE (95% CI: 0.00-0.01) and 0.07 for mortality (95% CI: 0.03-0.11). Our meta-analysis of 6 studies comparing the risk of complications and PE related to CDT with those related to anticoagulation showed that CDT was associated with an increased risk of complications (OR = 4.36; 95% CI: 2.94-6.47) and PE (OR = 1.57; 95% CI: 1.37-1.79).

CONCLUSION

Acute lower extremity DVT patients receiving CDT are associated with a low risk of complications. However, compared with anticoagulation, CDT is associated with a higher risk of complications and PE. Rare mortality related to thrombolytic therapy was reported. More evidence should be accumulated to prove the safety of CDT.

Thrombectomy Combined with Indwelling-catheter Thrombolysis is more Effective than Pure Thrombectomy for the Treatment of Lower Extremity Deep Venous Thrombosis

This study was a retrospective analysis of the efficacy of thrombectomy plus local catheter-directed thrombolysis (CDT) for the treatment of lower extremity deep venous thrombosis (LDVT).

The experimental group underwent thrombectomy plus LCDT, whereas the control group underwent thrombectomy plus systemic thrombolysis via the dorsalis pedis vein. Venography and vascular color Doppler ultrasound were performed 7 days after surgery and at follow-up. The differences in the thigh and calf circumferences of normal and affected limbs were compared between groups. The venous patency score and venous patency rate were used for outcome evaluation. Compared with the control group, the experimental group showed a lower venous patency score and higher venous patency rate after treatment (P<0.05). Thirty patients were followed for 3 to 6 months, and according to the last evaluation, the differences in thigh and calf circumference between the normal and affected limbs remained lower in the experimental group than in the control group (P<0.05). Moreover, the venous patency score was lower, and the venous patency rate was higher in the experimental group than in the control group (P<0.05).

Should catheter-directed thrombolysis be monitored?

Catheter-directed thrombolysis for deep venous thrombosis is considered the basic treatment modality for intrathrombus removal. This method is preferably used in patients with iliofemoral deep venous thrombosis due to poor spontaneous recanalization in this segment, especially on the left side. The method was published almost 25 years ago and has gained ground in the treatment because of poor results from systemic thrombolysis and because of the possibility of stenting any underlying iliac obstruction during the procedure. However, the publications of catheter-directed thrombolysis reveal a great heterogeneity concerning catheter-directed thrombolysis technique and the lack of high quality evidence about monitoring as a tool to minimize the risk of bleeding and pulmonary embolism. Strict inclusion and exclusion criteria, correct composition and infusion of thrombolysis agent, imaging thrombus clearance during catheter-directed thrombolysis, ensuring flow enhancement during the bedridden situation, careful evaluation of indication for stenting based on imaging, and sufficient conversion to anticoagulation treatment following catheter-directed thrombolysis are essential. The aim of this paper is to discuss different treatment aspects of catheter-directed thrombolysis for iliofemoral thrombosis and to suggest a monitoring model for future treatment.

Endovascular intervention for deep venous thrombosis in patients with inferior vena cava filters

Patients with inferior vena cava (IVC) filter-associated deep venous thrombosis (DVT) are a challenging subset of patients for endovascular intervention. Given the lack of available data pertaining to this clinical scenario, the purpose of this study was to evaluate the authors' experience with the use of endovascular treatment for DVT in patients with IVC filters. Primary aims included assessing the technical and clinical success, complications, and clinical patency in these patients. This was a retrospective single-center review of adult patients with IVC filters undergoing endovascular treatment of DVT between 1/2005 and 4/2014. Patient electronic medical records were reviewed for demographic data, anticoagulation status, symptoms, symptomatic extremities, extent of thrombosis, therapies received, technical and clinical success, and complications. Query yielded 82 patients (mean 53 years, range 18-96; 66% male), all of whom were included in our analysis. The majority of patients presented with lower extremity pain and swelling, with extensive clot burden despite the use of anticoagulant medication. Treatment elements utilized included pharmacologic lysis in 92%, mechanical thrombectomy in 77%, angioplasty in 63% and stent placement in 50% of patients. Interventions were technically successful in restoring flow in 87% of patients, and clinically successful in improving presenting symptoms in 79% of patients. By SIR criteria, 24% of patients experienced complications (categorized as 10% minor and 14% major). There were two deaths from intracranial hemorrhage. The probability of thrombosis-free survival at 1, 3, 6, 9 and 12 months was 0.85 (CI 0.74-0.93), 0.81 (CI 0.69-0.89), 0.74 (CI 0.62-0.83), 0.70 (CI 0.57-0.8) and 0.70 (CI 0.57-0.8), respectively. Endovascular interventions are usually effective in relieving symptoms in patients with DVT and pre-existing IVC filters. However, these outcomes are achieved with significant complication rates that may exceed those observed when endovascular therapy is provided for other DVT populations.

EkoSonic Thrombolysis as a Therapeutic Adjunct in Venous Occlusive Disease

The use of ultrasound waves in conjunction with local thrombolysis may accelerate clot resolution and serve as an important therapeutic adjunct in the treatment of venous occlusive disease. Our goal was to provide a larger sample population over a 5-year period to evaluate our experience with the EkoSonic endovascular system (EKOS, EKOS Corporation, Bothell, WA). We suspected that ultrasound-accelerated thrombolysis (UAT) using EKOS would provide excellent thrombolysis and midterm patency rates with minimal thrombolytic complications. A retrospective study was conducted to provide a case series with UAT using EKOS. Data were collected over a 5-year period. Primary end points included degree of thrombolysis. Secondarily, we analyzed thrombolytic usage, complication rates, and midterm patency, over a 1-year period. A total of 48 limbs were treated with UAT. Forty cases were diagnosed as acute, whereas the remaining 8 were chronic. Complete thrombolysis was successful in 38/48 (79%) of patients, and partial thrombolysis was accomplished in 10/48 (21%) of patients. Overall mean infusion time was 22.4 hours ±3.6. There were a total of three complications (6%), all of which were minor bleeding. One-year patency was shown to be 87% with no signs of valvular reflux. UAT using EKOS demonstrated effective rates of thrombolysis with very few complications. In addition, our 1-year patency rates were comparable to published data using conventional catheter-directed thrombolysis. UAT provides lytic therapy by utilizing the benefits of ultrasonic waves to help augment the fibrinolytic process. Our institution currently favors the use of EKOS as the treatment of choice in patients that are appropriate thrombolytic candidates.

Safety and Efficacy of Low Dosage of Urokinase for Catheter-directed Thrombolysis of Deep Venous Thrombosis

Background:

Catheter-directed thrombolysis (CDT) has been a mainstay in treating deep venous thrombosis (DVT). However, the optimal dosage of a thrombolytic agent is still controversial. The goal of this study was to evaluate the safety and efficacy of low dosage urokinase with CDT for DVT.

Methods:

A retrospective analysis was performed using data from a total of 427 patients with DVT treated with CDT in our single center between July 2009 and December 2012. Early efficacy of thrombolysis was assessed with a thrombus score based on daily venography. The therapeutic safety was evaluated by adverse events. A venography or duplex ultrasound was performed to assess the outcome at 6 months, 1 year and 2 years postoperatively.

Results:

The mean total dose of 3.34 (standard deviation [SD] 1.38) million units of urokinase was administered during a mean of 5.18 (SD 2.28) days. Prior to discharge, Grade III (complete lysis) was achieved in 154 (36%) patients; Grade II (50–99% lysis) in 222 (52%); and Grade I (50% lysis) in 51 (12%). The major complications included one intracranial hemorrhage, one hematochezia, five gross hematuria, and one pulmonary embolism. Moreover, no death occurred in the study.

Conclusions:

Treatment of low-dose catheter-directed thrombosis is an efficacious and safe therapeutic approach in patients with DVT offering good long-term outcomes and minimal complications.

Contemporary management of acute and chronic deep venous thrombosis

INTRODUCTION

This review aims to provide an update on the management of deep vein thrombosis (DVT).

SOURCES OF DATA

A systematic search of PubMed, Google Scholar and Cochrane databases was carried out.

AREAS OF AGREEMENT

Direct oral anticoagulants (DOACs) are as effective and easier to use than vitamin K antagonists for the treatment of DVT. Catheter-directed thrombolysis can reduce post thrombotic syndrome in patients with iliofemoral DVT. Compression bandaging can help heal a venous ulcer.

AREAS OF CONTROVERSY

Compression hosiery to prevent post thrombotic syndrome. Long-term evidence to show clinical benefit of using endovenous therapies to restore deep vein patency.

GROWING POINTS

Developing imaging methods to identify patients who would benefit from venous thrombolysis. The evolution of dedicated venous stents.

AREAS TIMELY FOR DEVELOPING RESEARCH

Understanding the mechanisms that lead to stent occlusion and investigation into the appropriate treatments that could prevent in-stent thrombosis is required.

Catheter-directed thrombolysis for extensive iliofemoral deep vein thrombosis: review of literature and ongoing trials

In patients with extensive lower limb deep vein thrombosis (DVT) that, typically, extends into the iliofemoral veins, catheter-directed thrombolysis (CDT) can achieve faster and more complete thrombus lysis as compared with systemic thrombolysis, while providing an acceptable safety profile through administration of lower doses of thrombolytic agents. Through a reduction in thrombus burden, CDT has the potential to mitigate the risk for post-thrombotic syndrome by restoring venous patency and preserving venous valve function. The efficacy of CDT may be improved by adjunctive approaches that include percutaneous mechanical thrombectomy, angioplasty with or without stenting, and ultrasound-assisted CDT. CDT may also have a specific therapeutic role in the management of iliofemoral DVT involving patients who are pregnant or with May-Thurner syndrome. This article summarizes the literature in this area and discusses recently completed and ongoing randomized trials on the use of CDT in patients with extensive lower limb DVT.

Randomized study of different approaches for catheter-directed thrombolysis for lower-extremity acute deep venous thrombosis

BACKGROUND/PURPOSE

To investigate the feasibility, effectiveness, and complications of catheter-directed thrombolysis (CDT) using three different approaches for acute lower-extremity deep venous thrombosis (DVT).

METHODS

A total of 106 patients with acute DVT were enrolled in this study. Forty-one patients received CDT through the small saphenous vein (Group A), 35 through the great saphenous vein (Group B), and 30 through the popliteal vein (Group C). Iliac vein balloon dilation and stenting was performed in 65 cases.

RESULTS

The vascular approach route was not statistically related to limb edema reduction rates (Groups A, B, and C: 82.3 ± 7.6% vs. 81.6 ± 6.0% vs. 83.9 ± 6.1%), nor to thrombolysis rates (63.5 ± 7.7% vs. 66.9 ± 8.4% vs. 66.1 ± 2.7%). The procedure was significantly shorter for Groups B and C. No significant difference was found between Groups B and C. Most complications occurred in Group A. The complication rate in Group B was the lowest. Eighty-eight patients were followed up for 7-24 months. Of these, 78 were pain-free and without limb edema; six showed rethrombosis.

CONCLUSION

CDT is an effective method to manage acute DVT. Of the three routes tested, the small saphenous vein route was associated with more frequent complications. Great saphenous vein catheterization was more effective because of its lower complication rate.

Basic data related to thrombolytic therapy for acute venous thrombosis

BACKGROUND

Treatment guidelines for thrombolysis in iliofemoral deep venous thrombosis (DVT) are based on a limited number of observational and prospective studies. The acute venous thrombosis: thrombus removal with adjunctive catheter-directed thrombolysis (ATTRACT) trial will be the first large, multicenter randomized control trial to evaluate the relative advantages of several current treatment strategies. The objective of this study was to summarize the existing data that inform the use of catheter-directed thrombolysis (CDT) or pharmacomechanical thrombectomy in the management of acute iliofemoral DVT.

METHODS

A search of the current literature was done using PubMed, Ovid, and Cochrane databases for all available articles published up to December 2013.

RESULTS

Of those studies, which included at least 25 patients, 19 case series were identified from 1996 to 2012. Treatment groups included anticoagulation, surgical thrombectomy, pharmacomechanical thrombectomy, and CDT. Cases observed in each ranged from 26 to 101. Three studies were identified which derived data from national multicenter registries. Only 2 randomized control trials were identified from 2002 to 2012. Both support the use of CDT over anticoagulation alone for treatment of iliofemoral DVT.

CONCLUSIONS

Present treatment guidelines for acute iliofemoral DVT have been in flux and are derived from a relatively small amount of clinical data. They are summarized here in anticipation of results from the ongoing ATTRACT trial.

Placement of vena cava filter via percutaneous puncture of the great saphenous vein

The aim of this study was to investigate the feasibility and safety of vena cava filter (VCF) placement via percutaneous puncture of the great saphenous vein (GSV) in the prevention of pulmonary embolisms. Using ultrasound positioning, VCF placement via percutaneous puncture of the GSV was performed on 12 patients with deep vein thrombosis (DVT) in the lower extremities. Transcatheter thrombolysis was conducted simultaneously. The postoperative filter position, puncture wound recovery and fluency of the GSV were observed. All filters were successfully released, with accurate positioning. No hematoma was observed at the puncture point during the perioperative period. In certain patients, local petechiae appeared around the puncture point during the thrombolysis period, which did not require special treatment. Re-examination using ultrasound revealed unobstructed blood flow in the GSV. VCF placement via percutaneous puncture of the GSV is a new filter placement method. The feasibility and safety of this method for the prevention of pulmonary embolisms has been demonstrated in a small number of sample cases.

[The role of thrombolysis in the clinical management of deep vein thrombosis]

Acute Deep Venous Thrombosis (DVT) therapies have been judged primarily on their ability to prevent symptomatic pulmonary embolism, early thrombus progression, and recurrent VTE. The cornerstones of current management of DVT, supported by the 2008 American College of Chest Physicians (ACCP) guidelines, are the routine use of anticoagulant therapy, graduated elastic compression stockings, and early ambulation. For selected appropriate patients with extensive acute proximal DVT, while the French recommendations (Afssaps 2009) still consider thrombolysis not indicated, ACCP guidelines now suggest in-situ thrombolysis in addition to anticoagulation to reduce the risk of subsequent postthrombotic syndrome (PTS) and recurrent DVT (Grade 2 B recommendation). Contemporary invasive endovascular treatments, called pharmacomechanical treatment, mitigate the drawbacks (major bleeding) historically associated with systemic thrombolytic approaches, by means of intra-thrombus delivery of drugs, followed by mechanical dispersion to accelerate lysis and then aspiration of remaining drug and clot debris. The proof of concept for the "open vein" hypothesis - that a strategy of early thrombus removal can reduce the incidence of PTS long term - comes incrementally and randomized trials (ATTRACT trial with a 2016 target completion date) are currently under way and might lead to a shift of the paradigms of the management of acute DVT focused on active thrombus removal.

Thrombolysis for deep venous thrombosis

The key questions addressed in this summary are whether clot removal should be part of the preferred therapy for patients with acute deep venous thrombosis (DVT), and whether there is evidence that a strategy of thrombus removal offers better outcomes for patients than anticoagulation alone. Evidence is defined as an outward sign or something that furnishes proof. Evidence in medicine is not limited to direct, blinded comparisons of one form of treatment compared with another but rather the body of knowledge that provides insight to clinicians to offer patient care. Evidence-based medicine follows from information available to form the foundation for the use of a treatment for a specific disease. Reports of strategies of thrombus removal for acute DVT, especially in patients with iliofemoral DVT, consistently demonstrate improved outcomes relative to postthrombotic morbidity. This summary reviews the evidence supporting this strategy as the preferred initial management of patients with extensive proximal DVT.

Low-dose, once-daily, intraclot injections of alteplase for treatment of acute deep venous thrombosis

PURPOSE

To evaluate the safety and efficacy of once-daily intraclot injections of low doses (≤ 10 mg) of tissue plasminogen activator (tPA) for thrombolysis of venous thrombosis.

MATERIALS AND METHODS

In prospective studies, 33 patients with subclavian, jugular, and central venous thrombosis (SJ-CVT) (all but two cases associated with central catheters) were treated once a day with ≤ 4 mg/day of tPA, and 30 patients with acute deep vein thrombosis of the lower extremity (DVT-LE) < 14 days old were treated once a day with ≤ 10 mg/leg/day of tPA by intraclot "lacing" of thrombus without continuous infusions of tPA.

RESULTS

Patency was restored in 26 (79%) of 33 patients with SJ-CVT using an average total dose of 7.1 mg of tPA/per patient and average of 2.1 treatments or days of therapy. Five patients received thrombolytic therapy for SJ-CVT as outpatients. Initial patency was restored in 29 (97%) of 30 patients with acute DVT-LE using an average total dose of 20 mg of tPA per patient over an average of 2.7 treatments/or days per patient. Follow-up imaging examinations at 6 months showed continued patency in 27 (96%)/of 28 patients. There were no major bleeding complications, and no patient required a blood transfusion.

CONCLUSIONS

Intraclot injection of low doses of alteplase is effective for acute venous thrombosis, and pharmacokinetic data suggest potentially greater safety.

Catheter-directed thrombolysis of proximal lower extremity deep vein thrombosis: a prospective trial with venographic and clinical follow-up

PURPOSE

To prospectively evaluate the primary and long-term venographic and clinical results of catheter-directed thrombolysis in the treatment of proximal deep vein thrombosis (DVT) of lower extremity.

MATERIALS AND METHODS

Fifty-six patients with mean age of 48 (range 15-81) years with acute DVT (symptom duration of less than 2 weeks), extending to high femoral (16 patients) or iliac vein (40 patients) were treated with selective catheter-directed thrombolysis. The mean total dose of 3.8 (range 1.0-8.1) million units of urokinase was administered during a mean of 39 (range 6-72) hours. Endovascular stenting was performed in 9 of the iliac DVT patients.

RESULTS

Complete procedural venographic success was achieved in 79% of patients. Major complications were noted in 7% of patients and the total rate of complications was 13%. Mean venographic follow-up was 3.5 years (range 3 months to 9.6 years); well preserved femoral vein valves and fully recanalized deep crural veins were observed in 83% and 57% of patients. Normal clinical findings in the affected limb were noted during the latest follow-up visit in 67% of patients. Clinical post-thrombotic syndrome occurred in 9% of patients.

CONCLUSION

Catheter-directed thrombolysis achieves good primary success with acceptable complication rate and effectively reduces prevalence of post-thrombotic syndrome.

Early Outcomes and Risk Factors in Venous Thrombectomy: An Analysis of the American College of Surgeons NSQIP Dataset

Objectives: Thrombus removal has been shown to improve venous physiology in acute iliofemoral deep-venous thrombosis. Our study focuses on the contemporary application of venous thrombectomy based on data from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). Methods: Data submitted by over 200 hospitals to the ACS NSQIP participant use file was accessed for the years 2005-2008. The ACS NSQIP protocol provides clinically rigorous preoperative risk and 30-day outcomes for a prospective and systematic sample of vascular surgery patients. Patients were identified who had undergone venous thrombectomy through leg access (Primary procedure CPT 34421 or 34451). Demographic and clinical variables along with 30-day morbidity (1 or more of 21 defined complications) and mortality were evaluated. Secondary/concomitant procedures CPT codes were collected. Univariate analysis between groups was performed using χ 2 or T-tests with P ≤ .05 considered significant. Results: A total of 91 patients were identified who underwent primary venous thrombectomy. The mean age was 62.5 ± 15.8 y and 45 of 91 (49.5%) were female. Thirty-day mortality was 8.8% (8/91). Composite morbidity was 25.3% (23/91). Intraoperative transfusion was required in 18.7% of the patients, lower extremity fasciotomy was performed in 8.8% of the patients and an inferior vena cava (IVC) filter was placed in 2.2% of the patients. An arteriovenous anastomosis was created in only 1 patient; venous angioplasty was performed in 3.3% of the patients. Conclusions: Venous thrombectomy is associated with significant postoperative morbidity and mortality. This is at least partially due to the associated comorbidities of this patient population, approximately 1/5 in our study were ASA class 4. Most frequent causes of morbidity are pulmonary and wound infection complications. Only 2 patients had an IVC filter placed during the operation. Adjunctive procedures to assist vein patency such as arteriovenous fistula creation or venous angioplasty were infrequently performed.

Iliac vein thrombosis: feasibility assessment of randomized controlled trials of endovascular pharmacomechanical thrombolysis

BACKGROUND

Optimal treatment for iliac vein thrombosis has not been established by randomized clinical trials largely owing to difficulty in patient recruitment. To assess the feasibility of a prospective randomized trial of thrombolysis and stenting, we determined the incidence of iliac vein thrombosis and randomization eligibility based on criteria for two ongoing trials.

METHODS

All patients with incident leg deep vein thrombosis during the calendar year 2005 seen at the Mayo Clinic were identified to determine the frequency of iliac vein involvement and the number undergoing endovascular therapies. Each patient was assessed for eligibility for potential randomization into a theoretic trial of thrombolytic therapy.

RESULTS

Ninety-five (of 394) patients had iliac vein involvement. Of these, only nine patients would have been suitable for randomization. Of the remaining 86 patients, prolonged symptom duration (n = 28), active cancer (n = 24) and advanced age (n = 19) were the most common exclusion criteria. Of 31 patients who had intervention, 75% had at least one contraindication for randomization.

CONCLUSIONS

Despite a philosophy of aggressive treatment for iliac vein thrombosis at this institution, the number of cases that could potentially be randomized into a clinical trial is relatively small. Trial design may require either multicenter cooperation or exclusion criteria revision for adequate recruitment.