Adjunctive Percutaneous Mechanical Thrombectomy for Lower-extremity Deep Vein Thrombosis: Clinical and Economic Outcomes

A systematic review and meta-analysis of the relative safety and efficacy of treating lower extremity deep vein thrombosis via pharmacomechanical thrombectomy and catheter-directed thrombolysis

OBJECTIVE

To evaluate the safety and efficacy of pharmacomechanical thrombectomy and catheter-directed thrombolysis (CDT) as approaches to treating deep venous thrombosis of lower extremities (LEDVT).

METHODS

The PubMed, Web of Science, Wanfang, Embase, Chinese Science and Technology Journal, Cochrane, and China National Knowledge Infrastructure (CNKI) databases were systematically searched for relevant articles published through October 2023, after which appropriate inclusion and exclusion criteria were used to screen out relevant articles. Review Manager 5.4.1 was used to extract key data from these studies, and pooled analyses were conducted based on mead difference (MD) or odds ratio (OR) values and corresponding 95% confidence interval (CI). Study quality was assessed with the Newcastle-Ottawa scale.

TRIAL REGISTRATION

This study has been registered at INPLASY.COM (No. INPLASY2023100075).

RESULTS

In total, 31 relevant studies enrolling 2413 patients were included in this meta-analysis, with 1184 and 1229 patients in the AngioJet and CDT groups, respectively. These analyses revealed that the AngioJet group exhibited significantly higher rates of early postoperative deep vein patency (MD = 7.73, 95% CI (3.29, 12.17), p = .0006) and affected limb symptom improvement (MD = 6.31, 95% CI (1.82,10.80), p = .006) relative to the CDT group, whereas no differences in grade II or III thrombus clearance rates (OR = 1.30, 95% CI (0.95, 1.77), p = .10) or changes in thigh circumference before and after treatment (MD = 0.01, 95% CI (-0.80, 0.83), p = .97) were observed. The AngioJet group also exhibited lower urokinase doses (MD = -145.33, 95% CI (-164.28,126.38), p < .00001), shorter thrombolysis time (MD = -2.35, 95% CI(-2.80, -1.90), p < .00001), a less prolonged hospital stay (MD = -3.13, 95% CI(-3.81, -2.45), p < .00001), lower rates of PTS incidence (OR = 0.56, 95% CI(0.36, 0.88), p = .01), and reduced complication rates (OR = 0.51, 95% CI(0.31, 0.83), p = .0007).

CONCLUSION

Studies published to date suggest that relative to CDT treatment, pharmacomechanical thrombectomy is associated with improved thrombus clearance, fewer complications, and lower complication rates in LEDVT patients, underscoring the safety and efficacy of this therapeutic strategy.

Histotripsy and Catheter-Directed Lytic: Efficacy in Highly Retracted Porcine Clots In Vitro

OBJECTIVE

Standard treatment for deep vein thrombosis (DVT) involves catheter-directed anticoagulants or thrombolytics, but the chronic thrombi present in many DVT cases are often resistant to this therapy. Histotripsy has been found to be a promising adjuvant treatment, using the mechanical action of cavitating bubble clouds to enhance thrombolytic activity. The objective of this study was to determine if histotripsy enhanced recombinant tissue plasminogen activator (rt-PA) thrombolysis in highly retracted porcine clots in vitro in a flow model of occlusive DVT.

METHODS

Highly retracted porcine whole blood clots were treated for 1 h with either catheter-directed saline (negative control), rt-PA (lytic control), histotripsy, DEFINITY and histotripsy or the combination of rt-PA and histotripsy with or without DEFINITY. Five-cycle, 1.5 MHz histotripsy pulses with a peak negative pressure of 33.2 MPa and pulse repetition frequency of 40 Hz were applied along the clot. B-Mode and passive cavitation images were acquired during histotripsy insonation to monitor bubble activity.

RESULTS

Clots subjected to histotripsy with and without rt-PA exhibited greater thrombolytic efficacy than controls (7.0% flow recovery or lower), and histotripsy with rt-PA was more efficacious than histotripsy with saline (86.1 ± 10.2% compared with 61.7 ± 19.8% flow recovery). The addition of DEFINITY to histotripsy with or without rt-PA did not enhance either thrombolytic efficacy or cavitation dose. Cavitation dose generally did not correlate with thrombolytic efficacy.

CONCLUSION

Enhancement of thrombolytic efficacy was achieved using histotripsy, with and without catheter-directed rt-PA, in the presence of physiologic flow. This suggests these treatments may be effective as therapy for DVT.

Cost Effectiveness of Early Endovenous Thrombus Removal for Acute Iliofemoral Deep Vein Thrombosis in the United Kingdom

OBJECTIVE

Early clot removal using endovascular intervention aims to reduce post-thrombotic syndrome (PTS) following iliofemoral deep venous thrombosis (DVT). This may reduce long term morbidity but incurs a higher initial cost. This study examined the cost effectiveness of catheter directed thrombolysis (CDT) and pharmacochemical thrombectomy (PMT) compared with oral anticoagulation (OAC) alone for treatment of acute iliofemoral DVT in the United Kingdom.

METHODS

A combined decision tree (acute DVT complications) and Markov model (long term complications [PTS]) was used for decision analytic modelling with five states: no PTS, mild PTS, moderate PTS, severe PTS, and dead. All patients started with acute DVT. Patients who survived acute complications transitioned into the Markov model. Cycle time was six months. A healthcare payer perspective and lifetime horizon was used, adjusting for excess mortality due to history of thrombosis. Data for probabilities, transition probabilities, mortality, and utilities were obtained from the published literature. Cost data were obtained from UK NHS tariffs and published literature. Outcomes were mean lifetime cost, quality adjusted life years (QALYs), and cost effectiveness.

RESULTS

Over a patient's lifetime, OAC was more costly (£37 206) than CDT (£32 043) and PMT (£36 288). Mean lifetime QALYs for OAC (12.9) were lower than CDT (13.5) and PMT (13.3). Therefore, in the incremental cost effectiveness analysis, both CDT and PMT were dominant: CDT was less costly (-£5 163) and more effective (+0.6 QALYs) than OAC, and PMT was also less costly (-£917) and more effective (+0.3 QALYs) than OAC. Results were robust to univariable sensitivity analyses, but probabilistic sensitivity analyses suggested considerable parameter uncertainty.

CONCLUSION

Early interventional treatment of iliofemoral DVT is cost effective in the UK. Future clinical and epidemiological studies are needed to characterise parameter uncertainty. Further analysis of modern practice, alternative treatments, and optimised care models is warranted.

Catheter-Directed Thrombolysis Protocols for Deep Venous Thrombosis of the Lower Extremities-A Systematic Review and Meta-analysis

OBJECTIVE

 To summarize characteristics, complications, and success rates of different catheter-directed thrombolysis (CDT) protocols for the treatment of lower extremity deep venous thrombosis (LE-DVT).

METHODS

 A systematic review using electronic databases (MEDLINE, Scopus, and Web of Science) was performed to identify randomized controlled trials and observational studies related to LE-DVT treated with CDT. A random-effects model meta-analysis was performed to obtain the pooled proportions of early complications, postthrombotic syndrome (PTS), and venous patency.

RESULTS

 Forty-six studies met the inclusion criteria reporting 49 protocols (n = 3,028 participants). In studies that addressed the thrombus location (n = 37), LE-DVT had iliofemoral involvement in 90 ± 23% of the cases. Only four series described CDT as the sole intervention for LE-DVT, while 47% received additional thrombectomy (manual, surgical, aspiration, or pharmacomechanical), and 89% used stenting.Definition of venogram success was highly variable, being the Venous Registry Index the most used method (n = 19). Among those, the minimal thrombolysis rate (<50% lysed thrombus) was 0 to 53%, partial thrombolysis (50-90% lysis) was 10 to 71%, and complete thrombolysis (90-100%) was 0 to 88%. Pooled outcomes were 8.7% (95% confidence interval [CI]: 6.6-10.7) for minor bleeding, 1.2% (95% CI: 0.8-1.7%) for major bleeding, 1.1% (95% CI: 0.6-1.6) for pulmonary embolism, and 0.6% (95% CI: 0.3-0.9) for death. Pooled incidences of PTS and of venous patency at up to 1 year of follow-up were 17.6% (95% CI: 11.8-23.4) and 77.5% (95% CI: 68.1-86.9), respectively.

CONCLUSION

 Assessment of the evidence is hampered by the heterogeneity of protocols, which may be reflected in the variation of PTS rates. Despite this, CDT is a low-risk treatment for LE-DVT.

Effectiveness and safety of catheter-directed thrombolysis in conjunction with percutaneous mechanical thrombectomy for acute iliofemoral deep vein thrombosis: A meta-analysis

BACKGROUND

Patients with severe acute low iliofemoral deep vein thrombosis (DVT), such as phlegmasia cerulea dolens, benefit from catheter-directed thrombolysis (CDT). This meta-analysis investigated the effectiveness and safety of adjuvant percutaneous mechanical thrombectomy (PMT) during CDT compared with CDT alone in the treatment of acute iliofemoral DVT.

METHODS

A meta-analysis was performed in accordance with the PRISMA guidelines. Medline, Embase, the Cochrane Library, China National Knowledge Internet, and Wanfang data were searched for studies on the management of acute iliofemoral DVT by means of CDT or CDT with adjuvant PMT. Randomized, controlled trials and nonrandomized studies were included. The primary outcomes were venous patency rate, major bleeding complications, and post-thrombotic syndrome occurrence within 2 years of the procedure. The secondary outcomes were thrombolytic time and volume, as well as the rates of thigh detumescence and iliac vein stenting.

RESULTS

The meta-analysis included 20 eligible studies with a total of 1686 patients. The rates of venous patency (mean difference, 10.11; 95% confidence interval [CI], 5.59-14.62) and thigh detumescence (mean difference, 3.64; 95% CI, 1.10-6.18) of the adjuvant PMT group were higher than those of the CDT alone group. Compared with CDT alone, the adjuvant PMT group experienced fewer incidences of major bleeding complications (odds ratio, 0.45; 95% CI, 0.26-0.77) and occurrences of post-thrombotic syndrome within 2 years of the procedure (odds ratio, 0.55; 95% CI, 0.33-0.92). Furthermore, the duration of thrombolytic therapy was shorter, and the total dose of administered thrombolytics was lower with adjuvant PMT.

CONCLUSIONS

Adjuvant PMT during CDT is associated with improved clinical outcomes and a lower incidence of major bleeding complications. The studies investigated were, however, single-center cohort studies, and future randomized controlled trials are needed to substantiate these findings.

Successful treatment of phlegmasia cerulea dolens with percutaneous thrombectomy and catheter-directed thrombolysis: A case report

INTRODUCTION

Phlegmasia cerulea dolens (PCD) is an uncommon condition of acute deep vein thrombosis, characterized by marked swelling of the affected limb with pain and cyanosis. High mortality and morbidity rates have been reported. Early diagnosis, quick and effective treatment are crucial for preventing potential limb loss or even death.

PATIENT CONCERNS

A 39-year-old woman presented to our emergency department with painful swelling and cyanotic discoloration of the left lower limb for 2 days.

DIAGNOSES

Computed tomography revealed thrombosis in the left common iliac vein and inferior vena cava. Angiography demonstrated extensive venous occlusion from the lower inferior vena cava to the left popliteal vein. The diagnosis of PCD was made.

INTERVENTIONS

Systemic anticoagulation with intravenous unfractionated heparin was initiated immediately. Mechanical thrombectomy with Angiojet and angioplasty were performed, and catheter-directed thrombolysis (CDT) was administered subsequently.

OUTCOMES

Follow-up angiography revealed regression of the thrombosis and the opacification of the deep vein was restored. The patient was discharged from the hospital uneventfully.

CONCLUSIONS

PCD is a rare but potentially limb and life-threatening condition that requires immediate recognition. Treatment should be in a timely manner. Anticoagulation alone may be inadequate and more aggressive management such as CDT and thrombectomy should be considered.

Percutaneous Thrombectomy for the Treatment of Lower Extremity Deep Vein Thrombosis: Medium-Term Follow-up Results and Analysis of 112 Cases

Introduction

The aim of this study was to analyze percutaneous thrombectomy (PT) outcomes for the management of lower extremity deep vein thrombosis (DVT) with medium-term follow-up.

Methods

The study included charts of patients who underwent PT due to lower extremity DVT between August 2017 and March 2021. Patient characteristics and procedure outcomes were recorded in the electronic information system on the same day as the procedure. The procedures with complete removal of thrombus following PT without requiring additional procedure or additional thrombectomy apparatus were considered successful. Also, duration of follow-up was noted.

Results

In total, 112 patients were enrolled in the study. The femoropopliteal (40.2%) and iliofemoral (25.0%) veins were the most common sites with thrombus detected. The duration of PT procedure and fluoroscopy were 123.1 minutes and 21.9 minutes, respectively. Estimated blood loss was 255.1 milliliters. The hospital stay and intensive care unit stay following PT were 3.7 and 1.4 days, respectively. Major hemorrhage did not occur in any patient, but we encountered bradycardia in six (5.4%) patients, acute renal failure in one (0.9%) patient, hemoglobinuria in 11 (9.8%) patients, leg pain in 15 (13.4%) patients, and pulmonary embolism in 2 (1.8) patients, respectively. Success of the present study was 94.6% in the first month, and re-operation was required only in one patient. The mean follow-up period was 21.1 months with 90.2% venous patency rates.

Conclusion

The present study demonstrated that PT was an effective and reliable treatment modality with acceptable complication rates for the treatment of lower extremity DVT. Additionally, the efficacy of PT was proven by mid-term follow-up results.

First-in-human experience of the Bashir Endovascular Catheter in the treatment of iliocaval deep vein thrombosis

Deep vein thrombosis (DVT) is a common disorder affecting approximately 900,000 new patients in the United States each year. Although the mainstay of treatment of DVT patients is therapeutic anticoagulation, some patients remain significantly symptomatic and therefore require more advanced interventions such as catheter-directed thrombolysis (CDT). We describe a case series of 13 patients with acute symptomatic inferior vena cava (IVC) and iliofemoral DVT that were treated with CDT using the Bashir Endovascular Catheter (BEC). We report the first-in-human use of BEC, which is a novel pharmacomechanical thrombolysis device. All the treated patients had complete and rapid resolution of their symptoms with excellent venous outflow. Despite initial promising results, larger studies using this catheter design will be needed to assess the role of BEC-directed therapy on rates of post-thrombotic syndrome and bleeding complications.

Endovascular Therapy for the Management of Acute Ilio-femoral Deep Vein Thrombosis

Ilio-femoral deep vein thrombosis (DVT) has a high rate of long-term morbidity in the form of the postthrombotic syndrome (PTS). Therefore, management of acute thrombosis should not only focus on the prevention of acute complications such as propagation or embolisation of the initial clot but also on preventing recurrent thrombosis and PTS. Contemporary catheter-based treatments of deep vein thrombosis have proven to be safe and effective in selected patients. Current guidelines recommend medical therapy with anticoagulation alone for all but the most severe, limb-threatening thrombosis. They additionally allow for consideration of endovascular catheter-based treatment in selected patients with acute proximal ilio-femoral DVT and low risk of bleeding complications to prevent PTS. 

Imaging-guided, catheter-based endovascular therapy has been used in selected patients to alleviate these sequelae, but important questions remain about their optimal use. In this article, we review the available evidence and summarize the rationale for use of catheter-based therapy in specific patient groups with acute iliofemoral DVT.

Comparing the efficacy of endovascular treatment for iliac vein compression syndrome with or without acute deep venous thrombosis: A single-center retrospective study

BACKGROUND

To compare the efficacy of endovascular treatment for iliac vein compression syndrome (IVCS) with or without acute deep venous thrombosis of lower extremity.

METHODS

This study retrospectively analyzed the clinical data of 300 IVCS patients, who received endovascular treatment between January 2013 and December 2017. According to whether IVCS was complicated by deep venous thrombosis or not, these patients were divided into non-thrombotic iliac vein lesion group (NIVL group, n = 127) and post-thrombotic iliac vein lesion group (PIVL group, n = 173). After endovascular treatment, all patients were followed up to assess the symptoms improvement and to evaluate the patency of iliac vein.

RESULTS

The technical success rate was 98% (294/300), and percutaneous transluminal angioplasty with stenting was adopted in 294 cases. The incidence of perioperative complications was 36.33% (109/300), but no severe complications occurred. During a mean follow-up of 22.3 months (range 6-30 months), 9(6.82%, 9/132) patients in PIVL group had recurrence of deep venous thrombosis, but nobody had deep venous thrombosis and varicose veins recurrence in NIVL group. The effective rate of endovascular treatment in NIVL group and PIVL group was 96.88% and 90.15% (P = 0.050), while the cumulative primary patency of iliac vein in NIVL group was significantly higher than that in PIVL group (P = 0.008).

CONCLUSIONS

The endovascular treatment is an effective, feasible, safe method for treating IVCS. There is no difference in the efficacy of IVCS patients with or without deep venous thrombosis, but the medium and long-term patency of patients with deep venous thrombosis is lower than that in patients without deep venous thrombosis.

AngioJet Thrombectomy Versus Catheter-Directed Thrombolysis for Lower Extremity Deep Vein Thrombosis: A Meta-Analysis of Clinical Trials

Early catheter-directed thrombolysis (CDT) for lower extremity deep vein thrombosis (LEDVT) can reduce post-thrombotic morbidity and the AngioJet thrombectomy is a new therapy that can be selected for the treatment of LEDVT. We performed a systematic review and meta-analysis of clinical trials comparing AngioJet versus CDT to assess the efficacy and safety of AngioJet thrombectomy. We systematically searched PubMed and Embase for clinical trials that published before November 1, 2020 and compared AngioJet thrombectomy and CDT in the treatment of LEDVT. We meta-analyzed effective rate of treatment, serious complications, PTS, Villalta score, duration of treatment and drug dose. AngioJet does not result in a significant difference in the effective rate (OR 1.00, CI 0.73-1.36, P = 0.98; I² = 0%) and complications (OR 1.16 CI 0.84-1.61, P = 0.36; I² = 39%) compare to CDT. And there was a statistically significant decrease in incidence of PTS (OR 0.58 CI 0.37-0.91, P = 0.02; I² = 0%) and Villalta score (OR −1.86 CI −3.49 to −0.24, P = 0.02; I² = 34%) for AngioJet compared to CDT. In addition, there was a statistically significant decrease in duration of the treatment (OR −2.45 CI −2.75 to −2.15, P < 0.0001; I² = 95%) and drug dose (OR −3.15 CI −3.38 to −2.93, P < 0.0001; I² = 98%) between AngioJet and CDT. AngioJet results in a low severity of PTS compared to CDT therapy. Moreover, the average duration of treatment and thrombolysis time was shorter in the AngioJet group compared to the CDT group. However, the AngioJet group was not significantly different in effective rate of treatment and serious complications compared to the CDT group.

The efficacy of rotational pharmaco-mechanical thrombectomy in patients with acute iliofemoral deep vein thrombosis: Is the standard treatment of deep vein thrombosis changing?

OBJECTIVE

In this study, we aimed to evaluate the efficiency of rotational thrombectomy device in pharmaco-mechanical thrombolysis for symptomatic acute ilio-femoral deep vein thrombosis.

MATERIALS AND METHODS

Between August 2013 and May 2018,82 patients with acute deep vein thrombosis comprising the iliofemoral segment whom underwent Pharmaco-mechanical thrombolysis were evaluated retrospectively. The Cleaner thrombectomy device was used. The resolution of thrombi was examined and graded. Development of post-thrombotic syndrome was assessed with Villalta scores.

RESULTS

75 patients (91.4%) had complete thrombus resolution. Between 50-99% resolution was noted in 6 patients (7.4%) and in one (1.2%) case less than %50 thrombus resolution was obtained. Seventy-five patients (91%) of the cohort could be treated in a single session; 7 patients (8.6%) required reintervention(s). Although improved post-thrombotic syndrome rates were lower at the short term, Villalta scores gradually increased during follow up.

CONCLUSIONS

In conclusion, Pharmaco-mechanical thrombolysis with Cleaner thrombectomy device is a safe and beneficial method for the treatment of acute iliofemoral deep vein thrombosis. Long term follow up data of large volume multicenter studies are warranted.

Trans-jugular AngioJet rheolytic thrombectomy for acute deep vein thrombosis: Alternative to overcome the limitation of patient's position

BACKGROUND

To introduce a transjugular retrograde approach for AngioJet rheolytic thrombectomy (RT) just after transjugular placement of inferior vena cava filter (IVCF) to treat acute deep vein thrombosis (DVT).

METHODS

From September 2018 to April 2019, transjugular Angiojet RT using pulse spray method was performed just after transjugular placement of IVCF in five patients (M:F = 3:2, mean age 70 years). Patients less than 165 cm in height with acute (<14 days) iliofemoral DVT were unable to assume a prone position. All patients underwent pre- and postprocedural venography to estimate thrombus reduction grade. Computed tomography angiograms at 3 and 6 months postoperative were compared with baseline scans. Post-thrombotic syndrome (PTS) symptoms were evaluated according to Villalta score during 12-month follow-up.

RESULTS

Mean procedure time for all procedures was 1.4 h. Thrombus was completely reduced in three patients and 50% to 99% reduction was noted in the other two. No patients had major complications during the hospital stay and follow-up period. Distal migration of IVCF occurred in one patient during the procedure and immediate IVCF repositioning was performed. No DVT remained in follow-up computed tomography scans of all patients. PTS did not develop in any patients during the follow-up period.

CONCLUSION

In patients who are unable to assume a prone position, a transjugular retrograde approach with AngioJet RT just after transjugular placement of IVCF to treat acute lower extremity DVT was a time-saving and easy alternative. During the procedure, attention to the guiding catheter position and AngioJet device movement was required to avoid affecting the IVCF.

Percutaneous Thrombectomy with the JETi8 Peripheral Thrombectomy System for the Treatment of Deep Vein Thrombosis

PURPOSE

This study evaluated the safety and efficacy of the JETi8 peripheral thrombectomy system in treating acute deep vein thrombosis (DVT).

MATERIALS AND METHODS

A retrospective study was conducted in 18 consecutive patients (mean age, 41 years old [range, 15-74 years old]; 5 men and 13 women). There were 21 instances of DVTs (9 iliofemoral, 10 axillosubclavian, and 2 portal), which were treated using the JETi8 thrombectomy device between November 2016 and July 2018. Thrombus was laced with recombinant tissue plasminogen activator (r-TPA) (9.3 mg, on average; range, 2-12 mg) in 17 procedures (81%) prior to thrombectomy. Technical success was defined as restoration of antegrade flow using the JETi8 with or without additional treatment of an underlying obstructive lesion. Procedural success was defined as technical success with or without the addition of overnight catheter-directed thrombolysis (CDT) RESULTS: Mean procedure time was 83 minutes (range, 30-160 minutes), and mean thrombus reduction with the JETi8 alone was 92% (range, 60%-100%). Stent placement was required in 6 procedures (29%). Technical success using the JETi8 system alone was 76% (16 of 21 procedures), whereas 5 procedures (24%) required subsequent overnight CDT in the intensive care unit. Procedural success rate was 100% (20 of 20 procedures). Mean aspirated volume was 531 mL (range, 250-1,230 mL). The only adverse event was a subsegmental pulmonary embolism. Seven patients (33%) were discharged the same day. Recurrent thrombosis was observed in 5 patients (24%), of whom 3 were successfully treated with the JETi8 system.

CONCLUSIONS

The JETi8 system may be a safe and effective option for thrombectomy of acute DVT.

In-hospital outcomes of catheter-directed thrombolysis versus anticoagulation in cancer patients with proximal deep venous thrombosis

OBJECTIVE

The objective of this study was to determine the rate of complications of catheter-directed thrombolysis (CDT) in cancer patients with deep venous thrombosis (DVT) compared with anticoagulation therapy alone.

METHODS

This observational study used the National Inpatient Sample database to screen for any cancer patients who were admitted with a principal discharge diagnosis of proximal lower extremity or caval DVT between January 2005 and December 2013. Patients treated with CDT plus anticoagulation were compared with those treated with anticoagulation alone using propensity score matching for comorbidities and demographic characteristics. The primary end point was in-hospital mortality. Secondary end points were acute intracranial hemorrhage, inferior vena cava filter placement, acute renal failure, blood transfusion rates, length of stay, and hospital charges.

RESULTS

We identified 31,124 cancer patients with lower extremity proximal or caval DVT, and 1290 (4%) patients were treated with CDT. Comparative outcomes as assessed in the two matched groups of 1297 patients showed that there was no significant difference in in-hospital mortality of patients undergoing CDT plus anticoagulation compared with those treated with anticoagulation alone (2.6% vs 1.9%; P = .23). However, CDT was associated with increased risk of intracranial hemorrhage (1.3% vs 0.4%; P = .017), greater blood transfusion rates (18.6% vs 13.1 %; P < .001), and higher rates of procedure-related hematoma (2.4% vs 0.4%; P < .001). The length of stay (6.0 [4.0-10.0] days vs 4.0 [2.0-7.0] days; P < .001) and hospital charges ($81,535 [$50,968-$127,045] vs $22,320 [$11,482-$41,005]; P < .001) were also higher in the CDT group compared with the control group.

CONCLUSIONS

There was no significant difference in in-hospital mortality of cancer patients who underwent CDT plus anticoagulation compared with anticoagulation alone. CDT was associated with increased in-hospital morbidity and resource utilization compared with anticoagulation alone. Further studies are needed to examine the effect of CDT on the development of PTS in this population.

Catheter Directed Lysis and Thrombectomy Are Equally Effective for Extensive Deep Vein Thrombosis

BACKGROUND

There is currently little consensus on the role of thrombectomy compared with catheter-directed lysis (CDL) for acute, extensive, proximal deep vein thrombosis (DVT). We sought to determine whether any differences in outcomes exist between thrombectomy and CDL in terms of postoperative venous patency, pulmonary emboli (PE), and bleeding/hematoma.

METHODS

In an institutional review board-approved retrospective cohort study, patients from a single academic medical center with confirmed lower extremity DVT were divided into thrombectomy and CDL cohorts. Demographic information, comorbidities and laboratory data, postoperative patency, postoperative bleeding, postoperative PE, popliteal hematoma, and recurrence of DVT were collected. Type I error level was set at 0.05.

RESULTS

Eighty-seven patients were identified, 51.7% received CDL, and 48.3% underwent thrombectomy. Patient comorbidities and hypercoagulable states were not significantly different among the groups. The two techniques did not have significantly different postoperative patency (P = 0.472), bleeding (P = 0.598), PE (P = 0.868), popliteal hematoma (P = 0.331), or recurrence of DVT (P = 0.835).

CONCLUSIONS

In selecting optimum treatment for acute, extensive, proximal DVT, our retrospective cohort study found no significant differences among treatment groups in safety, efficacy, recurrence, and progression to PE. We conclude that modality of treatment should be decided based on hospital resources, surgeon experience, and comfort with each technique, patient's physiologic status, and associated costs.

Pharmacomechanical Thrombectomy Versus Catheter-Directed Thrombolysis for Iliofemoral Deep Vein Thrombosis: A Meta-Analysis of Clinical Trials

Early catheter-directed thrombolysis (CDT) for deep vein thrombosis (DVT) can reduce postthrombotic morbidity. Pharmacomechanical thrombolysis (PMT) is a new therapy that can be selected for the treatment of iliofemoral deep vein thrombosis (IFDVT). We performed a meta-analysis of clinical trials comparing PMT versus CDT for treatment of acute IFDVT. Literature on this topic published between January 1, 1990, and June 1, 2018, was identified using PubMed, Embase, Cochrane Library, and Web of Science. Six trials were included in the meta-analysis. Compared to CDT, PMT significantly reduced the Villalta score ( P = .007; I² = 0%), thrombus score ( P = .01; I² = 0%), the duration in the hospital ( P = .03; I² = 64%), and thrombolysis time ( P < .00001, I² = 0%). There was no significant difference in valvular incompetence events ( P = .21; I² = 0%), minor bleeding events ( P = .59; I² = 0%), stent events ( P = .09; I² = 24%), and clot reduction grade I events ( P = .16; I² = 43%) between PMT and CDT. Subgroup analysis was performed by dividing the clot reduction grade I events group into PMT plus CDT versus CDT group and significant differences were found ( P = .03, I² = 0%) as well as for PMT alone versus CDT group ( P = .88, I² = 37%). This meta-analysis shows that PMT reduces the severity of postthrombotic syndrome (PTS), thrombus score, duration in hospital, and thrombolysis time compared to CDT. More specifically, PMT plus CDT reduces clot reduction grade I events. No significant difference in valvular incompetence events, stent events, and minor bleeding events were found when PMT was compared to CDT.

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.

Thrombectomy and thrombolysis for the prevention and treatment of postthrombotic syndrome

Postthrombotic syndrome (PTS) is a frequent complication of lower-extremity deep vein thrombosis (DVT), occurring in approximately 40% of patients despite the use of anticoagulant therapy. PTS causes significant impairment of patients' health-related quality of life, and no evidence-based therapies have been consistently effective. Catheter-directed thrombolysis and thrombectomy have been shown to remove acute thrombus, and it has been hypothesized they could prevent or reduce PTS. However, because these procedures can be associated with complications, mainly bleeding, randomized trial data are needed to determine when they should be used. In this article, I summarize the current status of thrombus removal procedures for DVT to provide contemporary guidance to clinicians seeking to individualize treatment decisions for their patients.

Catheter-directed thrombolysis to avoid late consequences of acute deep vein thrombosis

The application of catheter-based methods to treat acute deep vein thrombosis (DVT) has increased in recent years. Catheter-directed thrombolysis (CDT), introduced during the early 1990s, has shown the ability to rapidly eliminate thrombus and is used in many centers as a salvage therapy for DVT patients who exhibit a poor initial response to anticoagulant therapy. However, CDT has disadvantages in terms of safety and resource use. Although CDT methods have evolved substantially to try to address these issues, for most of the last 25years there was little high-quality data on CDT outcomes upon which to base patient care decisions. The paucity of evidence was particularly problematic for long-term outcomes such as recurrent venous thromboembolism (VTE) and the post-thrombotic syndrome (PTS). Fortunately, rigorous studies of CDT are now being completed. Accordingly, the purpose of this article is to: 1) state the known and unknown factors influencing risk and benefit with use of CDT and related methods to treat acute DVT; 2) summarize emerging evidence showing the patient outcomes that occur when CDT is used for first-line management of DVT; and 3) suggest clinical parameters for CDT utilization in light of the available evidence.

Single-center retrospective review of ultrasound-accelerated versus traditional catheter-directed thrombolysis for acute lower extremity deep venous thrombosis

Objective

Systemic anticoagulation remains the standard for acute lower extremity (LE) deep venous thrombosis (DVT), but growing interest in catheter-directed thrombolysis (CDT) and its potential to reduce the incidence of post-thrombotic syndrome (PTS) has led to advent of ultrasound-accelerated CDT (US-CDT). Few studies to date have examined the outcomes of US-CDT against traditional CDT (T-CDT).

Methods

This is a retrospective, single-center review of all patients treated for acute LE DVT over a five-year period with either US- and T-CDT. Patients were stratified based on demographics, presentation, co-morbidities, risk factors, and peri-procedural data.

Results

Seventy-six limbs in 67 patients were treated; 51 limbs in 42 patients were treated with US-CDT, and 25 limbs in 25 patients were treated with T-CDT. Adjuncts include: pharmacomechanical thrombolysis ( n = 28 vs. 20, p = 0.04), angioplasty ( n = 22 vs. 18, p = 0.11), stenting ( n = 30 vs. 6, p ≤ 0.001), and IVC filter insertion ( n = 5 vs. 0, p = 0.07). Mean lysis times were 21 ± 1.7 and 24 ± 1.8 h for US- and T-CDT, respectively ( p = 0.26). Thirty (25 ultrasound, 5 traditional) limbs had complete lysis. Thirty-one (22 ultrasound, 9 traditional) limbs had incomplete lysis. Fifteen (4 ultrasound, 11 traditional) limbs had ineffective lysis ( p = 0.002 in favor of ultrasound). Four patients (3 US-CDT, 1 T-CDT) had recurrent ipsilateral thrombosis within 30 days ( p = 0.60). By Kaplan-Meier analysis, there were no significant difference between primary patency, primary-assisted patency, secondary patency, re-thrombosis, and recurrent symptoms at 6, 12, and 24 months.

Conclusion

US-CDT does not significantly improve mid-term patencies but results in greater acute clot burden reduction in patients with acute LE DVTs compared to T-CDT, which may be beneficial in reducing the long-term incidence of PTS.

Interventional Management of Venous Thromboembolism: State of the Art

OBJECTIVE

The purpose of this article is to describe the indications for and approach to catheter-based treatment of acute venous thromboembolism (VTE).

CONCLUSION

Catheter-based treatment of VTE is a viable adjunct to anticoagulant therapy and is being rapidly adopted around the United States. Early data suggest that these therapies reduce postthrombotic sequelae and improve quality of life, but bleeding events are still frequent, particularly at low-volume centers. Protocols need to be standardized to improve patient care.

The postthrombotic syndrome: current evidence and future challenges

Postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that develops in 20-50% of patients. PTS manifests as a spectrum of symptoms and signs of chronic venous insufficiency that can impose significant morbidity and have a negative impact on quality of life. Chronic venous hypertension caused by a combination of residual venous obstruction and valvular reflux is believed to play a major role in the pathophysiology of PTS. The Villalta scale is the most widely applied clinical scale used to diagnose and define PTS. Proximal DVT and recurrent ipsilateral DVT are the two principal established risk factors for PTS, and efforts in recent years have been focused on identifying a combination of clinical and biomarker predictors that will define high-risk patients and possibly new therapeutic targets. The best way to prevent PTS is to prevent the occurrence of DVT, and to provide optimal anticoagulation for the acute phase of DVT once it occurs. Recent years have brought progress in our understanding of the role of endovascular techniques in the prevention and treatment of PTS and the subgroups of patients that may benefit from these modalities. Pharmacomechanical catheter-directed thrombolysis is the most promising interventional modality for prevention of PTS. This review summarizes the current state of evidence on PTS of the lower limbs, and highlights areas where uncertainty still exists that require further research.

Feasibility of continuous, catheter-directed thrombolysis using low-dose urokinase in combination with low molecular-weight heparin for acute iliofemoral venous thrombosis in patients at risk of bleeding

The present study aimed to examine the feasibility of catheter-directed thrombolysis (CDT) using continuous infusion of low-dose urokinase in combination with low molecular weight heparin (LMWH) for acute iliofemoral venous thrombosis. This retrospective analysis included patients with symptomatic acute iliofemoral venous thrombosis who received CDT using continuous infusion of low-dose urokinase in combination with LMWH within the past four years. Urokinase was administered at 1×10⁴ U/h and 2×10⁴ U/h in patients at high-risk and low-risk of bleeding, respectively. Measurements included urokinase dosage, duration, clinical outcomes and CDT-related complications. A total of 46 patients were included (high-risk, n=17; low-risk, n=29). In the high-risk patients, 64.7% experienced dissolution of ≥50% thrombi after a median CDT duration of 8 days (range, 6-10 days) and median total urokinase dose of 1.92×10⁶ units (range, 1.44-2.4×10⁶ units). In the low-risk patients, 82.8% achieved dissolution of ≥50% thrombi after a median CDT duration of 7 days (range, 4-10 days) and a median total urokinase dose of 3.36×10⁶ units (range, 1.92-4.80×10⁶ units). Remission of clinical symptoms after CDT was achieved in 15 (88.2%) and 28 (96.6%) cases in high-risk and low-risk patients, respectively. No treatment-associated pulmonary embolism or major bleeding was observed. Three (6.5%) subjects (high-risk, n=1; low-risk, n=2) experienced minor bleeding. In conclusion, continuous infusion of low-dose urokinase via CDT in combination with LMWH is effective and safe for acute iliofemoral venous thrombosis in patients with one or more risk factor for bleeding.

What is the definition of successful lysis: reporting standard?

Deep vein thrombosis, and the resultant development of post-thrombotic syndrome, is a significant health issue. Recent evidence demonstrates that the severity of post-thrombotic syndrome symptoms is directly related to the level of venous thrombosis and following treatment these subsequent symptoms are inversely related to the degree of thrombus removal. If we can improve, and preferably standardise the terminology associated with pre-treatment assessment of thrombus load and post-treatment success of thrombus removal techniques, we should then be able to choose more tailor-made techniques to greater benefit our patients. A number of scoring systems have been devised for the assessment of venous thrombus burden, with a majority impractical for everyday usage. In order to provide a more practical solution, the lower extremity thrombosis classification has been developed, using information on anatomical location for venous thrombus combined with a clinical indicator as to the likely sequelae. Anatomical success following venous thrombolysis can be defined by assessing restoration of anterograde flow in the treated vein or the percentage degree of thrombolysis, using venography. The second option is the method most frequently utilised, with the Venous Registry grading system applied. Data from recent trials have given us conflicting and confusing data mainly because we are not using standardised terminology. We urgently need to agree on a standard method of description of thrombus removal before stent placement which also incorporates the likely clinical impact of the area involved in the thrombosis.

Histotripsy Thrombolysis on Retracted Clots

Retracted blood clots have been previously recognized to be more resistant to drug-based thrombolysis methods, even with ultrasound and microbubble enhancements. Microtripsy, a new histotripsy approach, has been investigated as a non-invasive, drug-free and image-guided method that uses ultrasound to break up clots with improved treatment accuracy and a lower risk of vessel damage compared with the traditional histotripsy thrombolysis approach. Unlike drug-mediated thrombolysis, which is dependent on the permeation of the thrombolytic agents into the clot, microtripsy controls acoustic cavitation to fractionate clots. We hypothesize that microtripsy thrombolysis is effective on retracted clots and that the treatment efficacy can be enhanced using strategies incorporating electronic focal steering. To test our hypothesis, retracted clots were prepared in vitro and the mechanical properties were quantitatively characterized. Microtripsy thrombolysis was applied on the retracted clots in an in vitro flow model using three different strategies: single-focus, electronically-steered multi-focus and dual-pass multi-focus. Results show that microtripsy was used to successfully generate a flow channel through the retracted clot and the flow was restored. The multi-focus and the dual-pass treatments incorporating the electronic focal steering significantly increased the recanalized flow channel size compared to the single-focus treatments. The dual-pass treatments achieved a restored flow rate up to 324 mL/min without cavitation contacting the vessel wall. The clot debris particles generated from microtripsy thrombolysis remained within the safe range. The results of this study show the potential of microtripsy thrombolysis for retracted clot recanalization with the enhancement of electronic focal steering.

Etiology and treatment of acute inferior vena cava thrombosis

Inferior vena cava thrombosis (IVCT) is a rare but severe disease that is associated with a high rate of mortality. IVCT can be categorized into primary versus secondary thrombosis dependent upon the underlying pathophysiology. The diagnosis includes both clinical probability assessment as well as the imaging evaluation. The optimal therapeutic strategy remains the target of continued research. Although anticoagulation therapy remains fundamental in treating IVCT, its inherent limitations have led to the use of minimally invasive, endovascular treatment options, including transcatheter thrombolysis, mechanical thrombectomy or a combination of these techniques. This review focuses on the etiology, diagnostic assessment, and endovascular treatment options for IVCT.

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.

Efficacy of Retrievable Inferior Vena Cava Filter Placement in the Prevention of Pulmonary Embolism during Catheter-Directed Thrombectomy for Proximal Lower-Extremity Deep Vein Thrombosis

BACKGROUND

Inferior vena cava (IVC) filter placement is not indicated for thrombolytic interventional treatment for deep vein thrombosis (DVT). We analyzed the efficacy and feasibility of retrievable IVC filter placement for the preventive management of embolic shedding during catheter-directed thrombectomy (CDT) for DVT of lower extremity.

METHODS

Seventy patients (35 males and 35 females) who underwent retrievable IVC filter placement to prevent thrombus dislodgement during CDT in all symptomatic DVT with thrombus age suspected within 4 weeks of the lower extremity between March 2008 and January 2014 were included in this study. All patients underwent laboratory blood study, duplex ultrasound and/or computed tomography for diagnosis, treatment, and follow-up in accordance with treatment policy of our Uijeongbu St. Mary's hospital. Two types of retrievable IVC filters (OptEase Filter, Cordis, Roden, The Netherlands; Gunther Tulip Filter, Cook, Bloomington, IN) were used to prevent thromboembolic events during CDT. After filter placement, subcutaneous low-molecular-weight heparin and overlapped to warfarin or new oral anticoagulant tried to achieve a target international normalized ratio (INR) of 2.0-3.0 in warfarin patients.

RESULTS

The thrombus was dislodged through the IVC filter during catheter-directed thrombolytic therapy in 22 patients (31.4%). In 22 cases, the thromboses were trapped by the retrievable IVC filter, and follow-up images showed thrombus capture. Thirty-four patients (48.6%) received percutaneous transluminal angioplasty (PTA). Additional stents were inserted in 23 patients (32.8%). Pulmonary embolism (PE) was not observed in patients implanted with retrievable IVC filters.

CONCLUSIONS

Our study findings suggest that retrieval IVC filter placement during interventional treatments of DVT of lower extremity such as thrombectomy of vein thrombus with or without stent insertion at compressed deep vein is favorable and effective for protecting against PE or lethal complications. We recommend carefully that before the management of DVT thrombus of lower extremity, retrieval IVC filter placement should be considered for preventing morbidity related with the PE.

Guidance for the use of thrombolytic therapy for the treatment of venous thromboembolism

Patients with venous thromboembolism (VTE) are prone to the development of both short-term and long-term complications that can substantially affect their functional capacity and quality of life. Patients with deep vein thrombosis (DVT) often develop recurrent VTE or the post-thrombotic syndrome, whereas patients with pulmonary embolism (PE) can develop long-term symptoms and functional limitations along a broad spectrum extending to full-blown chronic thromboembolic pulmonary hypertension. Clinicians who care for patients showing severe clinical manifestations of DVT and PE are often faced with challenging decisions concerning whether and how to escalate to more aggressive treatments such as those involving the use of thrombolytic drugs. The purpose of this chapter is to provide guidance on how best to individualize care to these patients.

Incidental Finding of Inferior Vena Cava Atresia Presenting with Deep Venous Thrombosis following Physical Exertion

Inferior vena cava atresia (IVCA) is a rare but well described vascular anomaly. It is a rare risk factor for deep venous thrombosis (DVT), found in approximately 5% of cases of unprovoked lower extremity (LE) DVT in patients <30 years of age. Affected population is in the early thirties, predominantly male, often with a history of major physical exertion and presents with extensive or bilateral DVTs. Patients with IVC anomalies usually develop compensatory circulation through the collateral veins with enlarged azygous/hemizygous veins. Despite the compensatory circulation, the venous drainage of the lower limbs is often insufficient leading to venous stasis and thrombosis. We describe a case of extensive and bilateral deep venous thrombosis following physical exertion in a thirty-six-year-old male patient with incidental finding of IVCA on imaging.

Venous clot lysis and stenting

Venous thromboembolism (VTE) continues to represent a major source or mortality and morbidity. Although anticoagulation is the mainstay of therapy, adjunctive catheter-based interventions have shown substantial potential to improve clinically meaningful patient outcomes in patients with deep vein thrombosis (DVT), pulmonary embolism (PE), and the post-thrombotic syndrome (PTS). Catheter-directed thrombolysis (CDT) has been shown in a randomized trial to reduce the risk of PTS in patients with acute proximal DVT; data from a larger NIH trial is expected shortly. The use of CDT is being increasingly used for patients with submassive or massive pulmonary embolism. Preliminary studies suggest that endovascular stent placement and ablative therapies can improve quality-of-life in carefully selected patients with established PTS. In this article, we summarize the current status of thrombus removal and stent placement procedures for VTE and PTS, with the main purpose being to guide clinicians in individualizing treatment decisions for their challenging patients.

Endovascular Interventions for Acute and Chronic Lower Extremity Deep Venous Disease: State of the Art

The societal and individual burden caused by acute and chronic lower extremity venous disease is considerable. In the past several decades, minimally invasive endovascular interventions have been developed to reduce thrombus burden in the setting of acute deep venous thrombosis to prevent both short- and long-term morbidity and to recanalize chronically occluded or stenosed postthrombotic or nonthrombotic veins in symptomatic patients. This state-of-the-art review provides an overview of the techniques and challenges, rationale, patient selection criteria, complications, postinterventional care, and outcomes data for endovascular intervention in the setting of acute and chronic lower extremity deep venous disease. Online supplemental material is available for this article.

Interventional therapy for venous thromboembolism

Advances in image-guided, catheter-based interventions have shown great potential to improve outcomes in patients with venous thromboembolism. Catheter-directed thrombolysis has been shown in one randomized controlled trial to reduce the risk of post-thrombotic syndrome in patients with acute lower extremity deep vein thrombosis; data from a larger national institute of health trial are expected in early 2017. The use of catheter-directed thrombolysis is also being increasingly considered for patients with submassive or massive pulmonary embolism. Preliminary studies suggest that endovascular stent placement and ablative therapies may be used to reduce symptoms and improve quality of life in severely affected patients with established post-thrombotic syndrome. In this article, we summarize the risks and benefits of endovascular venous thromboembolism therapies as currently understood, highlight clinical situations where their benefit may outweigh risks, and describe ongoing and upcoming pivotal research initiatives with multidisciplinary participation.

An in-vitro study on corn-shaped balloon-enhanced thrombolysis

BACKGROUND

Glossy balloons were used to enhance deep vein thrombolysis. However, thrombi tend to yield in the balloon dilatation due to their smooth surface. It may be preferable to enhance thrombolysis by using balloons with a rough surface, instead of balloons with a smooth surface.

MATERIAL AND METHODS

Four rabbits were used for the experiment and 60 blood clot samples were obtained, and the samples were randomly separated into one control group and four balloon-solubilised groups. Urokinase solution (5000 U/ml) was used as the thrombolytic drug. The balloon-solubilised groups were enhanced respectively by 1 atm and 2 atm pressurised glossy balloons, and 1 atm and 2 atm pressurised corn-shaped balloons. Thrombolysis rates and residual rates for different granularities of blood clots were calculated for comparasion.

RESULTS

Thrombolysis rates of the groups using corn-shaped balloons were higher than those of the groups using glossy balloons (p = 0.003 and p = 0.002). Residual rates of Φ ≥ 3.7 mm blood clots for the groups using corn-shaped balloons were lower than those for the groups using glossy balloons (p < 0.001 and p < 0.001).

CONCLUSION

Balloons could be used to enhance thrombolysis; under the same balloon dilatation pressure, thrombolysis rates when using corn-shaped balloons are better than those when using glossy balloons.

Treating infrainguinal deep venous thrombosis

Endovascular DVT therapy has historically been directed at patients with the most extensive DVT. As evidence has been developed to support the use of catheter-directed thrombolysis for iliofemoral DVT, interventional radiologists are increasingly being referred patients with DVT that is anatomically less severe. In this article, we outline the key considerations that should be weighed in determining whether or not to provide aggressive therapy to patients with DVT limited to the femoropopliteal veins.

Pulmonary embolism and stroke associated with mechanical thrombectomy

Mechanical thrombectomy offers the advantage of rapid removal of venous thrombi. It allows venous obstructions to be removed and requires shorter duration of infusion of thrombolytic agents. However, aspiration of thrombi can lead to complications, particularly pulmonary embolism and hemolysis. The validity of using vena cava filters during thrombectomy in order to avoid embolism has not yet been established. The authors report a case of massive pulmonary embolism associated with ischemic stroke in a patient with a hitherto undiagnosed patent foramen ovale. The patient developed respiratory failure and neurological deficit after thrombectomy. This case raise questions about the value of the thrombectomy for the treatment of proximal vein thrombosis due to the risks of this procedure. The authors also discuss the need for vena cava filters and ruling out a patent foramen ovale in patients undergoing thrombectomy.

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.