Percutaneous manual aspiration thrombectomy followed by stenting for iliac vein compression syndrome with secondary acute isolated iliofemoral deep vein thrombosis: a prospective study of single-session endovascular protocol

The long-term prognosis of endovascular thrombectomy in patients with acute left iliofemoral vein thrombosis combined with left iliac vein compression

OBJECTIVE

This study investigated the long-term outcomes of different thrombus removal methods in patients with acute left iliofemoral vein thrombosis (IFDVT) accompanied by left iliac vein compression (LIVC).

METHODS

This was a single-center cohort study. 240 patients with acute left-sided IFDVT complicated by LIVC were categorized based on their treatment approach into two groups: those receiving anticoagulation alone (No-PCDT group) and those undergoing anticoagulation combined with pharmacomechanical catheter-directed thrombolysis (PCDT group). The PCDT group was further divided into three subgroups: anticoagulation combined with percutaneous mechanical thrombectomy (PMT group), anticoagulation combined with catheter-directed thrombolysis (CDT group), and anticoagulation combined with both percutaneous mechanical thrombectomy and catheter-directed thrombolysis (PMT+CDT group). The incidence of post-thrombotic syndrome (PTS) was assessed using Villalta scores and Venous Clinical Severity Scores (VCSS). Patients were followed up for 24 months to compare long-term outcomes.

RESULTS

The No-PCDT group consisted of 123 individuals, while the PCDT group comprised 117, with 36 in the CDT subgroup, 41 in the PMT subgroup, and 40 in the PMT+CDT subgroup. The follow-up period ranged from 3 to 24 months. The PCDT group was associated with a reduced incidence of PTS and a lower risk of high VCSS (Villalta scale ≥5 or presence of ulcer: 22% PCDT vs. 39% No-PCDT; OR, 0.446; 95% CI, 0.253-0.787; P=0.005; and VCSS≥4: 22% PCDT vs. 34% No-PCDT; OR, 0.551; 95% CI, 0.311-0.978; P=0.042). Among the three subgroups of PCDT cohort, compared to the CDT group, the PMT group showed a decreased incidence of PTS and a lower risk of high VCSS (Villalta scale ≥5 or ulcer: 12% PMT vs. 39% CDT; OR, 0.218; 95% CI, 0.069-0.690; P=0.010; and VCSS≥4: 12% PMT vs. 36% CDT; OR, 0.246; 95% CI, 0.077-0.781; P=0.017). The PMT+CDT group also demonstrated a reduced incidence of PTS (18% PMT+CDT vs. 39% CDT; OR, 0.333; 95% CI, 0.116-0.958; P=0.041) compared to the CDT group, but did not show a significant reduction in the risk of high VCSS (20% PMT+CDT vs. 36% CDT; P=0.121). Compared to the PMT group, the PMT+CDT group did not significantly reduce the incidence of PTS (12% PMT vs. 18% PMT+CDT; P=0.504) or the rate of high VCSS (12% PMT vs. 20% PMT+CDT; P=0.343).

CONCLUSIONS

In patients with acute left IFDVT complicated by LIVC, PMT may serve as a more efficacious method for thrombus removal compared to CDT and combined PMT+CDT in reducing both the incidence of PTS and the risk of high VCSS.

Syringe-assisted test-aspiration with mechanical aspiration thrombectomy results in good safety and short-term outcomes in the treatment of patients with deep venous thrombosis

OBJECTIVE

To evaluate the short-term outcomes and safety of syringe-assisted test-aspiration with mechanical aspiration thrombectomy in the treatment of deep venous thrombosis.

METHODS

This was a single-center, retrospective study of hospitalized patients with iliofemoral and/or inferior vena caval deep venous thrombosis, excluding those with pulmonary embolism. We collected the following patient data from the electronic medical records: age, sex, provoked/unprovoked deep venous thrombosis, symptom duration, thrombosed segments, and the presence of a tumor, thrombophilia, diabetes, and/or iliac vein compression syndrome. Venography and computed tomographic venography were performed in all patients before the procedure. All patients underwent syringe-assisted test-aspiration with mechanical aspiration thrombectomy under local anesthesia and sedation, and all received low-molecular-weight heparin peri-operatively. All patients underwent implantation of an inferior vena caval filter. Rivaroxaban was administered post-procedure, instead of heparin, for 3-6 months, with lower extremity compression.

RESULTS

Overall, 29 patients with deep venous thrombosis underwent syringe-assisted test-aspiration with mechanical aspiration thrombectomy from January 2022 to October 2022 in our institution. Technical success (>70% thrombus resolution) was achieved in all patients, and using a single procedure in 25/29 patients (86%). Concomitant stenting was performed in 18/29 (62%) of the patients, and 21/29 (69%) underwent angioplasty. The median (interquartile range) procedure time was 110 min (100-122), the median intra-operative bleeding volume was 150 mL (120-180), and the median decrease in the hemoglobin concentration from pre- to post-operative was 7 g/L (4-14). The median follow-up duration was 7 months (5-9). All patients obtained symptomatic relief, and 27/29 achieved near-remission or full remission (combined total). No patients experienced peri-operative bleeding complications, or symptom recurrence or post-thrombectomy syndrome during follow-up.

CONCLUSION

The short-term outcomes following syringe-assisted test-aspiration with mechanical aspiration thrombectomy in the treatment of deep venous thrombosis were excellent, and the procedure was safe.

Endovascular Venous Interventions - A State-of-the-Art Review

Venous vascular diseases are an important clinical entity estimated to affect several million people worldwide. Deep vein thrombosis (DVT) is a common venous disease with a population variable prevalence of 122 to 160 persons per 100,000 per year, whereas pulmonary embolism (PE) affects up to 60 to 70 per 100 000 and carries much higher mortality. Chronic venous diseases, which cause symptoms like leg swelling, heaviness, pain, and discomfort, are most prevalent in the elderly and significantly impact their quality of life. Some estimate that chronic vascular diseases account for up to 2% of healthcare budgets in Western countries. Treating venous vascular disease includes using systemic anticoagulation and interventional therapies in some patient subsets. In this comprehensive review, we discuss endovascular treatment modalities in the management of venous vascular diseases.

Multi-factor analysis of failure for modified single-session Angiojet rheolytic thrombectomy in treatment of acute iliofemoral venous thrombosis from iliac vein compression syndrome

PURPOSE

To explore the risk factors of failure for modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression with iliofemoral vein thrombosis.

METHODS

During September 2017 to September 2021, 278 patients with DVT were retrospectively analyzed and 203 were eligible for inclusion. All patients were tried to take modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval treatment. The perioperative factors were analyzed between groups: group 1-modified single-session therapy succeed, and group 2-modified single-session therapy failed. The high risk factors of failure group were evaluated by logistic regression analysis.

RESULTS

48 patients failed in modified single-session therapy, up to 23.64%. Single factor analysis indicated that there were five independent risk factors related with the failure (p < 0.05), including course of disease longer than 7 days, lumbar degeneration-related iliac vein compression syndrome (dIVCS), antegrade vein access, balloon-assisted cracking thrombus, and suction time. Logistic regression analysis indicated that course of disease longer than 7 days (OR = 19.642.95%CI:6.776∼56.933), dIVCS (OR = 11.586.95%CI:4.016∼33.427) were high risk factors for modified single-session therapy failed, antegrade vein access (OR = 0.171.95%CI:0.047∼0.614) and balloon-assisted cracking thrombus (OR = 0.157.95%CI:0.045∼0.542) were protective factors for therapy failure (p < 0.05).

CONCLUSIONS

Long course of disease and dIVCS are the high risk factors for failure of modified single-session Angiojet rheolytic thrombectomy combined with directed iliac vein stenting, directed filter retrieval in the treatment of iliac vein compression syndrome (IVCS). But, antegrade vein access and balloon-assisted cracking thrombus intraoperatively may improve the success rate of modified single-session treatment.

Clinical outcomes of AngioJet pharmacomechanical thrombectomy versus catheter-directed thrombolysis for the treatment of filter-related caval thrombosis

BACKGROUND

The inferior vena cava filter is utilized worldwide to intercept thrombi and to reduce the risk of fatal pulmonary embolism (PE). However, filter-related thrombosis is a complication of filter implantation. Endovascular methods such as AngioJet rheolytic thrombectomy (ART) and catheter-directed thrombolysis (CDT) can treat filter-related caval thrombosis, but the clinical outcomes of both treatment modalities have not been determined.

AIM

To compare the treatment outcomes of AngioJet rheolytic thrombectomy vs catheter-directed thrombolysis in patients with filter-related caval thrombosis.

METHODS

In this single-center retrospective study, 65 patients (34 males and 31 females; mean age: 59.0 ± 13.43 years) with intrafilter and inferior vena cava thrombosis were enrolled between January 2021 and August 2022. These patients were assigned to either the AngioJet group (n = 44) or the CDT group (n = 21). Clinical data and imaging information were collected. Evaluation measures included thrombus clearance rate, periprocedural complications, urokinase dosage, incidence of PE, limb circumference difference, length of stay, and filter removal rate.

RESULTS

Technical success rates were 100% in the AngioJet and CDT groups. In the AngioJet group, grade II and grade III thrombus clearance was achieved in 26 (59.09%) and 14 (31.82%) patients, respectively. In the CDT group, grade II and grade III thrombus clearance was accomplished in 11 (52.38%) patients and 8 (38.10%) patients, respectively (P > 0.05).The peridiameter difference of the thigh was significantly reduced in patients from both groups after treatment (P < 0.05). The median dosage of urokinase was 0.08 (0.02, 0.25) million U in the AngioJet group and 1.50 (1.17, 1.83) million U in the CDT group (P < 0.05). Minor bleeding was shown in 4 (19.05%) patients in the CDT group, and when it was compared with that in the AngioJet group, the difference was statistically significant (P < 0.05). No major bleeding occurred. Seven (15.91%) patients in the AngioJet group had hemoglobinuria and 1 (4.76%) patient in the CDT group had bacteremia. There were 8 (18.18%) patients with PE in the AngioJet group and 4 (19.05%) patients in the CDT group before the intervention (P > 0.05). Computed tomography angiopulmonography (CTA) showed that PE was resolved after the intervention. New PE occurred in 4 (9.09%) patients in the AngioJet group and in 2 (9.52%) patients in the CDT group after theintervention (P > 0.05). These cases of PE were asymptomatic. The mean length of stay was longer in the CDT group (11.67 ± 5.34 d) than in the AngioJet group (10.64 ± 3.52 d) (P < 0.05). The filter was successfully retrieved in the first phase in 10 (47.62%) patients in the CDT group and in 15 (34.09%) patients in the AngioJet group (P > 0.05).Cumulative removal was accomplished in 17 (80.95%) out of 21 patients in the CDT group and in 42 (95.45%) out of 44 patients in the ART group (P > 0.05). The median indwelling time for patients with successful retrieval was 16 (13139) d in the CDT group and 59 (12231) d in the ART group (P > 0.05).

CONCLUSION

Compared with catheter-directed thrombolysis, AngioJet rheolytic thrombectomy can achieve similar thrombus clearance effects, improve the filter retrieval rate, reduce the urokinase dosage and lower the risk of bleeding events in patients with filter-related caval thrombosis.

Diagnostic Value of the Iliac Vein Stenosis Percentage Combined With Indicators of Venous Reflux for Iliac Vein Compression Syndrome With Computed Tomography Venography

OBJECTIVES

To identify a cutoff value of iliac vein stenosis in computed tomography venography (CTV) for assisting in the diagnosis of iliac vein compression syndrome (IVCS). Meanwhile, determining whether the inclusion of venous return and collateral imaging findings could further enhance the diagnostic performance.

METHODS

We conducted a retrospective study on 264 patients suspected of IVCS who underwent both CTV and digital subtraction venography (DSV) from January 2016 to December 2020; they were assigned to either a control group (n = 101) or an IVCS group (n = 163) based on the DSV results. The narrowest anteroposterior diameter of the common iliac vein and the anteroposterior diameter of the distal end were measured to calculate the percentage of iliac vein stenosis. Receiver operating characteristic curve analysis was performed to determine the predictive accuracy of the percentage of iliac vein stenosis for IVCS and whether the inclusion of venous reflux indicators can further improve the diagnostic accuracy.

RESULTS

With respect to the DSV results, the area under the curve was 0.797 (P < 0.001). The best cutoff value was 46.67%, corresponding to a sensitivity of 83.44% and a specificity of 69.31% for predicting IVCS. Moreover, the combination diagnostic method had higher sensitivity and accuracy (94.48% vs 83.44% [P = 0.01] and 84.85% vs 78.03% [P = 0.04], respectively).

CONCLUSIONS

The best cutoff percentage of iliac vein stenosis to diagnose IVCS was 46.67% with CTV. The sensitivity and accuracy of the combined diagnostic method were higher than those of the iliac vein stenosis ratio diagnostic method.

Percutaneous Mechanical Thrombectomy for Acute Symptomatic Iliofemoral Deep Venous Thrombosis Patients With Recent Aneurysmal Subarachnoid Hemorrhage

PURPOSE

To investigate the efficacy, safety, and mid-term outcomes of percutaneous mechanical thrombectomy (PMT) for acute symptomatic iliofemoral deep venous thrombosis (DVT) patients with recent (within 4 weeks) aneurysmal subarachnoid hemorrhage (aSAH).

MATERIALS AND METHODS

From January 2016 to February 2020, 11 acute symptomatic iliofemoral DVT patients with a recent history of aSAH were enrolled in this study. All patients had a history of aneurysm ligation or clipping previously, computed tomography (CT) scans revealed ventricular hemorrhage had been absorbed obviously and no residual aneurysm. The mean time of DVT onset after aSAH ictus was 19.2±4.5 days, and the mean Glasgow score was 6.8 ± 0.7 (range, 6-8). These patients underwent PMT with an 8 French Aspirex^®S device (Straub Medical AG, Wangs, Switzerland), subsequent stenting was performed to relieve the underlying stenosis, followed by anticoagulation alone. The procedure-related complications were assessed after intervention. The follow-ups were conducted up to 1 year, the patency was evaluated via duplex ultrasonography, and the incidence of post-thrombotic syndrome (PTS) was evaluated using the Villalta scale.

RESULTS

Grade III (>90%) clearance was achieved in all 11 patients. Stenting was performed in 7 patients (63.6%). There were no cerebral rebleeding events or other severe complications except 1 puncture site bleeding during treatment. A total of 90.9% (10 of 11) of patients were alive at the 12 month follow-up, and 7 patients achieved a good functional outcome. At the 1 year follow-up, there was 1 patient (10%) with mild PTS. The ultrasound showed that the patency of the iliofemoral veins was 100%, and femoral valvular incompetence was observed in 1 patient.

CONCLUSION

Percutaneous mechanical thrombectomy seems to be a feasible and safe treatment for acute iliofemoral DVT in selected patients with recent aSAH, and it shows promising results in restoring patency and reducing the risk of PTS.

Technical Success and Short-Term Results From Mechanical Thrombectomy for Lower Extremity Iliofemoral Deep Vein Thrombosis Using a Computer aided Mechanical Aspiration Thrombectomy Device

BACKGROUND

Symptoms of deep vein thrombosis include severe pain and swelling, and complications can include post-thrombotic syndrome or recurrent venous thromboembolism. Aspiration thrombectomy (AT) treats arterial and venous disease by removing acute thrombus without reliance on thrombolytics, but also has the potential to remove fresh blood. Intelligent aspiration is designed to minimize blood loss during AT by aspirating continuously while in thrombus but only intermittently when in a patent vascular segment with active flow. The Indigo System with Lightning 12 intelligent aspiration (Penumbra, Inc. Alameda, California) utilizes an automatic valve controlled by a proprietary computer algorithm to optimize thrombus removal and minimize blood loss. This Computer aided Mechanical Aspiration Thrombectomy (CMAT) system was used on 16 consecutive patients and initial results are discussed here.

METHODS

This retrospective review included patients undergoing CMAT for iliofemoral acute DVT between July 2020 and June 2021. The primary outcome was greater than 70% thrombus removal as determined by multiplanar venography. Secondary outcomes included single session therapy, blood loss during aspiration, the need for post-procedure blood transfusion, thrombolytic use, symptom resolution prior to discharge, and periprocedural complications.

RESULTS

Sixteen patients (mean age 58.6 years [range 31-80], 75.0% women) underwent CMAT using Lightning 12. All patients presented with pain and swelling from 2-16 days in duration. There were no cases of phlegmasia. Access was obtained via the popliteal (11), posterior tibial (3), small saphenous (1) or soleal (1) vein. Thrombus reduction of >70% or better was achieved in 100% (16/16) of patients. Single session therapy was successful in 93.8% (15/16) of patients. Eight patients (50%) received stents. All patients achieved symptom resolution prior to discharge. Median blood loss was 155.0 ml (Interquartile range [IQR] 95.0, 187.5), and no patients received post-procedure transfusion. One patient received angioplasty post-thrombectomy, and adjunctive tissue plasminogen activator (tPA) was used in 6.2% (1/16) patients. No patients developed postoperative acute kidney failure. There were no periprocedural complications. At 1 to 8-month follow-up, 93.8% (15/16) patients had patency of the treated iliofemoral area and 87.5% (14/16) had no recurrent symptoms.

CONCLUSIONS

These results suggest that CMAT using Lightning 12 is safe for clot removal in patients with acute iliofemoral DVT with a high rate of single-session technical success and symptom resolution. In this case series, Lightning 12 was also associated with low blood loss, and no patients required blood transfusion.

A Systematic Review and Meta-Analysis of 12-Month Patency After Intervention for Iliofemoral Obstruction Using Dedicated or Non-Dedicated Venous Stents

BACKGROUND

Endovascular stenting of the deep venous system has been proposed as a method to treat patients with symptomatic iliofemoral outflow obstruction. The purpose of this systematic review and meta-analysis was to compare the effectiveness of this treatment at 1-year following the development of dedicated venous stents.

METHOD AND RESULTS

We searched MEDLINE and EMBASE for studies evaluating the effectiveness of venous stent placement. Data were extracted by disease pathogenesis: non-thrombotic iliac vein lesions (NIVL), acute thrombotic (DVT), or post-thrombotic syndrome (PTS). Main outcomes included technical success, stent patency at 1 year and symptom relief. A total of 49 studies reporting outcomes in 5154 patients (NIVL, 1431; DVT, 950; PTS, 2773) were included in the meta-analysis. Technical success rates were comparable among groups (97%-100%). There were no periprocedural deaths. Minor bleeding was reported in up to 5% of patients and major bleeding in 0.5% upon intervention. Transient back pain was noted in 55% of PTS patients following intervention. There was significant heterogeneity between studies reporting outcomes in PTS patients. Primary and cumulative patency at 1 year was: NIVL-96% and 100%; DVT-91% and 97%; PTS (stents above the ligament)-77% and 94%, and; PTS (stents across the ligament)-78% and 94%. There were insufficient data to compare patency outcomes of dedicated and nondedicated venous stents in patients with acute DVT. In NIVL and PTS patients, stent patency was comparable at 1 year. There was inconsistency in the use of validated tools for the measurement of symptoms before and after intervention. When reported, venous claudication, improved in 83% of PTS patients and 90% of NIVL patients, and ulcer healing occurred in 80% of PTS patients and 32% of NIVL patients.

CONCLUSIONS

The first generation of dedicated venous stents perform comparably in terms of patency and clinical outcomes to non-dedicated technologies at 1 year for the treatment of patients with NIVL and PTS. However, significant heterogeneity exists between studies and standardized criteria are urgently needed to report outcomes in patients undergoing deep venous stenting.

Three-Year Results from the Venovo Venous Stent Study for the Treatment of Iliac and Femoral Vein Obstruction

Purpose

To assess safety and patency of the Venovo venous stent for the treatment of iliofemoral vein obstruction.

Materials and Methods

Twenty-two international centers enrolled 170 patients in the VERNACULAR study (93 post-thrombotic syndrome; 77 non-thrombotic iliac vein lesions). Primary outcome measures were major adverse events at 30 days and 12-month primary patency (freedom from target vessel revascularization, thrombotic occlusion, or stenosis > 50%). Secondary outcomes included the Venous Clinical Severity Score Pain Assessment and Chronic Venous Quality-of-Life Questionnaire assessments (hypothesis tested). Secondary observations included primary patency, target vessel and lesion revascularization (TVR/TLR), and assessment of stent integrity through 36 months.

Results

Freedom from major adverse events through 30 days was 93.5%, statistically higher than a pre-specified performance goal of 89% (p = 0.032) while primary patency at 12 months was 88.6%, also statistically higher than a performance goal of 74% (p < 0.0001). Mean quality-of-life measures were statistically improved compared to baseline values at 12 months (p < 0.0001). Primary patency at 36 months was 84% (Kaplan–Meier analysis) while freedom from TVR/TLR was 88.1%. There was no stent embolization/migration, and no core laboratory assessed stent fractures reported through 36 months. Six deaths were reported; none adjudicated as device or procedure related.

Conclusion

The Venovo venous stent was successfully deployed in obstructive iliofemoral vein lesions and met the pre-specified primary outcome measures through 12 months. At 3 years, primary patency was 84%, reintervention rates were low, standardized quality-of-life and pain measures improved from baseline, and there was no stent migration or fractures.

Level of Evidence

Level 2—prospective, multicenter, controlled clinical study without a concurrent control or randomization. Pre-specified endpoints were hypothesis-tested to performance goals derived from peer-reviewed clinical literature.

Registration clinicaltrials.gov

Unique Identifier NCT02655887.

Application of manual aspiration thrombectomy in the treatment of deep vein thrombosis in cancer patients: Descriptive retrospective cohort study

OBJECTIVES

To determine the outcomes and feasibility of endovascular treatment, mainly based on manual aspiration thrombectomy (MAT) with adjunctive percutaneous balloon angioplasty with or without stent deployment, for treatment of symptomatic ilio-femoral deep vein thrombosis (IFDVT) in cancer patients.

MATERIALS AND METHODS

In this retrospective cohort study, 135 consecutive patients (56 men; mean age, 63 years; 149 limbs) with acute (n = 113; 83.7%) and subacute to chronic (n = 22; 16.3%) symptomatic IFDVT underwent MAT-based endovascular treatment. Among them, adjunctive balloon angioplasty and stent placement was performed in 94 patients. Technical and clinical success regarding stage and cause of DVT was assessed.

RESULTS

Technical success (complete thrombus removal without residual thrombus or stenosis) was achieved in 89.6%, and subjective symptom improvement was stated by 71.5% of treated patients. The primary patency rates were 88.1%, 81.6%, 76.0%, 74.1% and 69.1% at 1, 3, 6, 12, and 30 months, respectively. Recurrent IFDVT occurred in 19.3% (26/135) of patients, 0.79 cases per patients-years of follow up. According to the analysis by causes of IFDVT, recurrence rate was 19.3% (11/57), 21.2% (12/57), and 14.3% (3/21) in unknown, compression/invasion of the vein by cancerous mass, and May-Thurner syndrome groups, respectively (p = 0.798). No procedure-related complication developed.

CONCLUSIONS

Endovascular treatment based on MAT is a feasible treatment option with favorable outcomes and minimal risk of complication in cancer patients with symptomatic IFDVT.

Contemporary treatment of May-Thurner Syndrome

Compression of the left common iliac vein by the overlying right common iliac artery is a benign anatomic abnormality in most individuals. However, in patients with significant vein compression, outflow obstruction and chronic intraluminal venous damage may lead to May-Thurner Syndrome. This syndrome commonly manifests as unilateral left leg swelling or acute iliofemoral deep venous thrombosis. In addition to clinical findings, diagnosis is made with ultrasound, computed tomography venography, or magnetic resonance venography. The extent of compression of the iliac vein is best determined by venography with intravascular ultrasound. Symptoms and hemodynamic significance of the compression guides the ideal treatment approach. Iliocaval stenting has become the standard treatment for this condition and has promising patency rates and clinical outcomes. This review paper provides an overview of pathophysiology, and utility and limitations of the existing diagnostic modalities and treatment options in the management of May-Thurner Syndrome.

A retrospective comparison of thrombectomy followed by stenting and thrombectomy alone for the management of deep vein thrombosis with May-Thurner syndrome

OBJECTIVE

To summarize the clinical results of thrombectomy with stenting (TBS) in patients with deep venous thrombosis (DVT) secondary to May-Thurner syndrome (MTS) compared with the outcomes in patients treated with thrombectomy alone (TB).

METHODS

A retrospective observation of patients with proximal DVT secondary to MTS was conducted in our institution. Patients accepted treatment including either catheter-directed TBS or TB. The complications and stent patency rates were recorded after treatments. The clinical results were assessed in both groups. The independent predictors for in-stent restenosis were further calculated in this study.

RESULTS

We included 372 patients with DVT secondary to MTS. Two hundred twenty-one patients received treatment with thrombectomy with TBS and 151 with TB. A longer mean procedure time (65.1 ± 13.9 minutes vs 49.5 ± 15.7 minutes; P < .001) and higher venous perforation rate (23 patients vs 5 patients; P = .011) were observed in the TBS group than in the TB group. The median follow-up time was 34 months. The patency rates in the TBS group at 36 months were as follows: primary patency rate of 74.0% and secondary patency rate of 92.1%. Independent predictors for restenosis included visible remaining collateral vessels (hazard ratio [HR], 1.12-3.29; P = .02), residual thrombus (HR, 1.40-4.38; P = .002), and tapered iliac vein (HR, 1.26-4.06; P = .006). Clinical results, including Venous Clinical Severity Scores (TBS, 8.0 ± 3.0; TB, 11.4 ± 3.2), Chronic Venous Insufficiency Questionnaire score (TBS, 76.4 ± 4.0; TB, 83.1 ± 4.6), Villalta scores (TBS, 3.8 ± 1.7; TB, 6.6 ± 3.2), and edema scores (TBS, 0.7 ± 0.7; TB, 1.6 ± 0.6), improved significantly in the TBS group.

CONCLUSIONS

TBS is effective and feasible for patients with proximal DVT secondary to MTS. Furthermore, compared with TB, additional stenting might be effective in improving the venous clinical results at follow-up observations.

Side-hole catheters have higher thrombus aspiration efficiency than regular end-hole catheters in an in vitro model

PURPOSE

We aimed to evaluate and compare thrombus aspiration efficiency between side-hole and end-hole thrombus-aspirating catheters.

METHODS

Using an in vitro model of acute thrombus occlusion, we performed thrombus aspiration with two catheter designs. Two end-hole and two side-hole catheters, 8 F and 10 F in diameter, were examined. Thrombus aspiration was performed with each catheter 30 times, and the amount of thrombotic material aspirated in each attempt was determined. The mean weight of the thrombotic material and the mean weight of the non-fluid thrombotic material extracted in all 30 attempts by each catheter were also determined.

RESULTS

The 10 F side-hole catheter aspirated more thrombotic material than did the 10 F end-hole catheter (44.76 g vs. 28.35 g). The 8 F side-hole catheter had higher thrombus aspiration capacity than did the 8 F end-hole catheter in terms of the mean weight of the aspirated thrombus at each aspiration attempt (1.41 g vs. 0.58 g; P < 0.001) and the mean volume of the aspirated thrombotic material at each aspiration attempt (1.79 mL vs. 1.01 mL; P < 0.001). The mean weight of the non-fluid thrombotic material aspirated with the side-hole catheters was higher than that aspirated by the end-hole catheters with the same diameter size (31.06 g vs. 22.41 g for the 10 F catheters; P < 0.001; and 4.54 g vs. 2.99 g for the 8 F catheters; P < 0.001).

CONCLUSION

Side-hole catheters are more effective in aspirating acute thrombi. The added benefit of the side-hole design is more remarkable in smaller-sized catheters. Animal models are needed to examine their aspiration capacity in a real elastic vascular conduit and in the presence of wall-adherent thrombi.

Outcome of AngioJet mechanical thrombus aspiration in the treatment of acute lower extremities deep venous thrombosis

OBJECTIVES

The objective of this study was to evaluate the efficacy and safety in patients with acute lower extremity deep venous thrombosis who underwent pharmacomechanical thrombectomy (PMT, AngioJet mechanical thrombus aspiration).

METHODS

In this retrospective, 424 consecutive patients with acute lower extremity deep venous thrombosis from three institutions were enrolled in the study from January 2015 to December 2018. Of these, patients were divided into two groups, AngioJet group (n = 186) and catheter-directed thrombolysis (CDT) group (n = 238). Evaluation indexes including limb circumference difference, length of stay (LOS), urokinase dosage, periprocedural complications, follow-up imaging findings and villalta scores were analyzed from the medical records.

RESULTS

A total of 424 patients diagnosed with acute lower extremity deep venous thrombosis were collected in this study. These patients were categorized into AngioJet group and CDT group. Significant differences were observed between the two groups with respect to the thigh circumference difference (5.32 ± 1.85 cm vs. 4.69 ± 2.15 cm; p = 0.04), calf circumference difference (2.79 ± 1.54 cm vs. 2.35 ± 1.25 cm; p = 0.01), thigh detumescence rate (72.19 ± 19.55% vs. 65.35 ± 17.26%; p = 0.00) and calf detumescence rate (62.79 ± 18.56% vs. 55.75 ± 17.27%; p = 0.00). The mean dose of urokinase in AngioJet group was 95.16 ± 45.89 million IU significantly less than that in the CDT group 293.76 ± 42.71 million IU (p = 0.00). The overall bleeding complication rate was 9.91% (19 patients in AngioJet group and 23 patients in CDT group), which included three major (0.71%, 3/424) and 39 minor (9.2%,39/424) events. In the AngioJet group, serum creatinine (sCr) concentration and urine erythrocyte from the hemolysis caused by the mechanical process were higher than baseline data at admission (p = 0.00, p = 0.00). The postoperative red blood cell and hemoglobin in two groups were lower than baseline data (p = 0.00, p = 0.00). Compared with CDT, AngioJet thrombectomy has significantly lower estimated incidence of PTS in the follow-up.

CONCLUSION

AngioJet thrombectomy has stronger clearance ability for acute lower extremity deep venous thrombosis leading to significant reduction in the consumption of hospital resources, total dose of thrombolytic agents, and infusion time, thereby preventing adverse bleeding events, but patients with renal insufficiency should be careful. Ideal short-term and medium-term efficacy and safety are certain.

ACR Appropriateness Criteria® Radiologic Management of Iliofemoral Venous Thrombosis

Iliofemoral venous thrombosis carries a high risk for pulmonary embolism, recurrent deep vein thrombosis, and post-thrombotic syndrome complicating 30% to 71% of those affected. The clinical scenarios in which iliofemoral venous thrombosis is managed may be diverse, presenting a challenge to identify optimum therapy tailored to each situation. Goals for management include preventing morbidity from venous occlusive disease, and morbidity and mortality from pulmonary embolism. Anticoagulation remains the standard of care for iliofemoral venous thrombosis, although a role for more aggressive therapies with catheter-based interventions or surgery exists in select circumstances. Results from recent prospective trials have improved patient selection guidelines for more aggressive therapies, and have also demonstrated a lack of efficacy for certain conservative therapies. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

May-Thurner syndrome: History of understanding and need for defining population prevalence

Patients with May-Thurner syndrome (MTS) are at elevated risk of developing an extensive left iliofemoral deep vein thrombosis (DVT; localized blood clot) due to an anatomical variant where the right common iliac artery compresses the left common iliac vein against the lumbar spine. While MTS was initially presumed to be rare when it was first anatomically defined in 1957, case reports of this syndrome have recently become more frequent, perhaps due to improved imaging techniques allowing for enhanced visualization of the iliac veins. Still, the population burden of this condition is unknown, and there is speculation it may be higher than generally perceived. In the present review, we (a) review history of how MTS became recognized, (b) describe practical challenges of studying MTS in population-based settings due to the specialized imaging required for diagnosis, (c) discuss why the contribution of MTS to DVT may be underestimated, (d) describe uncertainty regarding the degree of venous compression which leads to DVT, and (e) outline future research needs. Our goal is to raise awareness of MTS and spark additional research into the epidemiology of this condition, which may be an underappreciated causative venous thromboembolism risk factor.

Risk Assessment of Deep Venous Thrombosis and Its Influencing Factors in Burn Patients

The objective of this study is to explore the relevant risk factors of deep venous thrombosis (DVT) in burn patients. A retrospective analysis was conducted for the medical records of 845 hospitalized burn patients from September 2012 to August 2017. Caprini thrombosis risk assessment scale (CTRAS) was employed for evaluating the risks of DVT. Based upon whether or not DVT occurred, they were divided into non-DVT group (n = 830) and DVT group (n = 15). Among 360 (42.7%) patients with high-risk Caprini scores, only 30 patients received color Doppler examination of lower limb veins, and 15 patients were diagnosed as DVT with a diagnostic rate of 1.8%. Caprini scores of non-DVT and DVT groups were 4.30 ± 2.71 and 9.87 ± 1.46 points, respectively. There was statistically significant difference (P < .05). As revealed by stepwise Logistic regression analysis, age, lower limb burn, wound infection, femoral vein catheterization, and long bedriddening time (>40 days) were independent risk factors for DVT. Burn patients are particularly prone to develop DVT. Age, wound infection, femoral vein catheterization, and long bedriddening time (>40 days) are risk factors. Aggressive preventive measures of DVT should be implemented.

Endovenous Intervention of May-Thurner Syndrome with Thrombus beyond Iliac Vein Stenosis

Purpose

With the increase in the incidence of venous thrombosis, interest in May-Thurner syndrome (MTS) accompanying iliac vein compression has increased. Some patients with MTS have inferior vena cava thrombosis or thrombosis beyond iliac vein stenosis (TBIVS). This study aimed to identify the characteristics of MTS with TBIVS including pulmonary embolism (PE) and post-thrombotic syndrome (PTS) compared to those of MTS without TBIVS.

Materials and Methods

Thirty-five patients with deep vein thrombosis associated with MTS were treated between March 2012 and February 2016. Demographic data, medical history, computed tomography findings (iliac vein size of stenosis and stenotic ratio compared with the other side), and clinical outcomes (preoperative PE and PTS) were retrospectively collected and reviewed by dividing into groups with or without TBIVS.

Results

Eight of the 35 patients with MTS had TBIVS. The group with TBIVS had a statistically significantly greater iliac vein size (P<0.001) and ratio (P=0.001). PE was more prevalent in the group with TBIVS (63% vs. 15%, P=0.007). However, no statistically significant intergroup difference in PTS prevalence was found.

Conclusion

The presence of mild iliac vein stenosis in MTS can be used to predict TBIVS and the requirement for more attention to PE.

In vitro investigation of a new thrombus aspiration and autologous blood reinfusion system

Purpose

The aim of the study was to evaluate the feasibility of a new venous-thrombus aspiration and autologous blood (auto-blood) reinfusion system.

Materials and methods

We constructed the venous model from polyvinyl chloride (PVC) tubes and three-way unions using a fresh clot of chicken blood as the venous thrombus. Eight French and 12F aspiration catheters were used to aspirate the thrombus in the right–pulmonary-artery model, 8 French and 14F aspiration catheters were used in the inferior–vena cava model, and 8 French and 10F aspiration catheters were used in the left–iliofemoral-vein model. A thrombus filtration and auto-blood reinfusion bottle was used to filter the thrombus and re-infuse auto-blood. We evaluated the thrombus aspiration capability of each catheter by comparing pre-aspirated with the post-aspirated thrombus volume, and we evaluated the difference in aspiration capability between the two catheters in each model by comparing their thrombus aspiration rates. We used Student's t-test for statistical analysis.

Results

Differences between pre-aspirated and post-aspirated thrombus volumes for each catheter were insignificant, as were those between the thrombus aspiration rates of the two catheters in each venous model. Using the thrombus aspiration and auto-blood reinfusion system, each aspiration catheter could fluently aspirate the thrombus out of the venous model.

Conclusion

In this study, we designed a new venous-thrombus aspiration system. This system could be used to aspirate acute venous thrombi and re-infuse autologous blood.

Arterial Compression of Left Iliac Veins: Five-Year Patency Rates of Endovascular Treatment

Endovascular angioplasty and stenting have become a treatment of choice for severely symptomatic left iliac veins under external, arterial compression. Patency rates of stented iliac veins based on ultrasonographic (US) findings were estimated. Retrospective analyses of gender, age, deep venous thrombosis (DVT) prior to stenting, stent location at common and/or external iliac veins, and patency rates from 1 month to 5 years were performed. Patients treated were mostly women (72 of 79, 91%), aged 51 ± 16 (25-89) years. Patency rates were 96% at 1 month, 89% at 1 year, and 85% at 3 to 5 years, best for common iliac, 95%, than for external iliac vein stents, subgroup with prior DVT, with secondary patency rates of 75%. US demonstrated acceptable patency rates for iliac vein stenting showing good performance for common iliac vein stents but a decreased performance with stent extending to the external iliac vein or stents placed in patients with prior iliac DVT.

Catheter directed interventions for acute deep vein thrombosis

Venous thromboembolism (VTE) is an extremely common form of vascular disease and impacts a great number of patients worldwide. Acute deep vein thrombosis (DVT) is a subset of VTE and is traditionally been treated with anticoagulation. There is good quality data which suggests the use of catheter directed interventions for the treatment of acute DVT with the aim of reducing post-thrombotic syndrome (PTS). The present review will discuss the various therapies available for acute DVT, focusing on catheter directed interventions, ranging from traditional anticoagulation to the most novel forms of aspiration thrombectomy.

Imaging of venous compression syndromes

Venous compression syndromes are a unique group of disorders characterized by anatomical extrinsic venous compression, typically in young and otherwise healthy individuals. While uncommon, they may cause serious complications including pain, swelling, deep venous thrombosis (DVT), pulmonary embolism, and post-thrombotic syndrome. The major disease entities are May-Thurner syndrome (MTS), variant iliac vein compression syndrome (IVCS), venous thoracic outlet syndrome (VTOS)/Paget-Schroetter syndrome, nutcracker syndrome (NCS), and popliteal venous compression (PVC). In this article, we review the key clinical features, multimodality imaging findings, and treatment options of these disorders. Emphasis is placed on the growing role of noninvasive imaging options such as magnetic resonance venography (MRV) in facilitating early and accurate diagnosis and tailored intervention.

Safety and Effectiveness of Stent Placement for Iliofemoral Venous Outflow Obstruction: Systematic Review and Meta-Analysis

BACKGROUND

Endovenous recanalization of iliofemoral stenosis or occlusion with angioplasty and stent placement has been increasingly used to maintain long-term venous patency in patients with iliofemoral venous outflow obstruction. The purpose of this systematic review and meta-analysis was to determine safety and effectiveness of venous stent placement in patients with iliofemoral venous outflow obstruction.

METHODS AND RESULTS

We searched MEDLINE and EMBASE for studies evaluating safety or effectiveness of stent placement in patients with iliofemoral venous outflow obstruction. Data were extracted by disease pathogenesis: nonthrombotic, acute thrombotic, or chronic post-thrombotic. Main outcomes included technical success, periprocedural complications, symptom relief at final follow-up, and primary/secondary patency through 5 years. A total of 37 studies reporting 45 treatment effects (nonthrombotic, 8; acute thrombotic, 19; and chronic post-thrombotic, 18) from 2869 patients (nonthrombotic, 1122; acute thrombotic, 629; and chronic post-thrombotic, 1118) were included. Technical success rates were comparable among groups, ranging from 94% to 96%. Complication rates ranged from 0.3% to 1.1% among groups for major bleeding, from 0.2% to 0.9% for pulmonary embolism, from 0.1% to 0.7% for periprocedural mortality, and from 1.0% to 6.8% for early thrombosis. Patient symptom relief data were reported inconsistently. At 1 year, primary and secondary patency were 96% and 99% for nonthrombotic, 87% and 89% for acute thrombotic, and 79% and 94% for chronic post-thrombotic.

CONCLUSIONS

Stent placement for iliofemoral venous outflow obstruction results in high technical success and acceptable complication rates regardless of cause of obstruction.

Single-Session Endovascular Treatment of Symptomatic Lower Extremity Deep Vein Thrombosis: Is it Possible Even for Aged Thrombosis

BACKGROUND

Feasibility of single-session mechanical thrombetomy, without thrombolytics, for the treatment of the subacute deep vein thrombosis (DVT) of the lower extremity remains poorly described.

PURPOSE

To evaluate the feasibility and efficacy of single-session endovascular treatment of DVT of the lower extremity that is more than 10 days old.

MATERIALS AND METHODS

From January 2010 to December 2013, single-session endovascular treatment was performed in 21 limbs of 21 patients (8 men and 13 women) with DVT more than 10 days old at our hospital. The mean age of the thrombosis was 21.5 days (range 11-45 days). Two patients had malignancy-related obstructions. A 14F introducer sheath was inserted through the popliteal vein followed by aspiration thrombectomy with a large bore catheter. Balloon angioplasty and/or maceration of the thrombus were added when needed. Stent insertions were performed for patients with combined iliac vein stenosis. Technical success, clinical success, mean procedure time, and complications were evaluated.

RESULTS

The technical success rate was 90.5% (19 of 21 patients). Among the 19 successful cases, aspiration thrombectomy alone was performed in 16 (84.2%) patients, additional balloon angioplasty of the femoral vein was performed in 2 (10.5%) patients, and both balloon angioplasty of the femoral vein and rotational thrombectomy were performed in 1 (5.3%) patient. Iliac vein stenting was performed due to combined iliac vein narrowing in 13 (68.4%) of the 19 successful cases. The mean procedure time was 86 minutes (26-179 minutes). All of the patients with technical success (19 of 21 patients) showed marked improvement in symptoms at the time of discharge (clinical success). Unexplained gastrointestinal hemorrhage developed in 1 patient.

CONCLUSION

Single-session endovascular treatment is feasible and effective even for patients with aged deep vein thrombosis of the lower extremity more than 10 days old.

Prophylactic Placement of an Inferior Vena Cava Filter During Aspiration Thrombectomy for Acute Deep Venous Thrombosis of the Lower Extremity

Purpose:

To evaluate the effect of an inferior vena cava (IVC) filter during aspiration thrombectomy for acute deep vein thrombosis (DVT) in the lower extremity.

Materials and Methods:

From July 2004 to December 2013, a retrospective analysis of 106 patients with acute DVT was performed. All patients received an IVC filter and were treated initially with aspiration thrombectomy. Among the 106 patients, DVT extension into the IVC was noted in 27 but was not evident in 79. We evaluated the presence of trapped thrombi in the filters after the procedure. The sizes of the trapped thrombi were classified into 2 grades based on the ratio of the maximum transverse length of the trapped thrombus to the diameter of the IVC (Grades I [≤ 50%] and II [> 50%]).

Results:

A trapped thrombus in the filter was detected in 46 (43%) of 106 patients on final venograms. The sizes of the trapped thrombi were grade I in 12 (26.1%) patients and grade II in 34 (73.9%). Among the 27 patients with DVT extension into the IVC, 20 (74.1%) showed a trapped thrombus in the filter, 75% (15 of 20) of which were grade II. Among the 79 patients without DVT extension into the IVC, 26 (32.9%) showed a trapped thrombus in the IVC filter, 73% (19 of 26) of which were grade II.

Conclusions:

Thrombus migration occurred frequently during aspiration thrombectomy of patients with acute DVT in the lower extremity. However, further studies are needed to establish a standard protocol for the prophylactic placement of an IVC filter during aspiration thrombectomy.

A phantom model study to identify the most effective manual aspiration thrombectomy for acute deep-vein thrombosis of the lower extremity

AIM

To identify the most effective manual aspiration thrombectomy (MAT) method for the initial endovascular management of acute deep-vein thrombosis (DVT) in the lower extremity using a phantom model.

MATERIALS AND METHODS

An acute DVT phantom model was created by infusing a bovine acute thrombus in a 20-mm diameter, 120-cm long plastic tube with banding of the distal portion. A total of 32 types of aspiration methods using combinations of two aspiration catheters (8 and 10 Fr), four syringes (10, 20, 40, and 50 ml), and four different aspiration methods (I, II, III, and IV) were performed. Each method was performed 10 times. The total weight of the aspirated thrombus was measured and compared among the 32 aspiration methods. The aspiration methods were classified based on the length of the dynamic catheter withdrawal (0 cm [method I], 15 cm [II], 30 cm [III], or >45 cm [IV]) while maintaining continuous negative pressure using a syringe. Analysis of variance and Student's t-test were used for statistical analysis.

RESULTS

There were no statistically significant differences in the total amount of aspirated thrombus among the various types of aspiration catheters and syringes; however, different aspiration methods showed significantly different results. Acute thrombus was most effectively aspirated by method IV irrespective of the catheter and syringe used. The longer the length of dynamic catheter withdrawal, the greater the amount of total thrombi that could be aspirated, irrespective of the type of aspiration catheter and syringe used (IV > III > II > I; p<0.05).

CONCLUSION

MAT can be performed most effectively using method IV. Effective MAT relies on the length of the dynamic catheter withdrawal while maintaining continuous negative pressure using a syringe in the initial endovascular management of acute DVT in the lower extremity.

Iliac vein compression syndrome: Clinical, imaging and pathologic findings

May-Thurner syndrome (MTS) is the pathologic compression of the left common iliac vein by the right common iliac artery, resulting in left lower extremity pain, swelling, and deep venous thrombosis. Though this syndrome was first described in 1851, there are currently no standardized criteria to establish the diagnosis of MTS. Since MTS is treated by a wide array of specialties, including interventional radiology, vascular surgery, cardiology, and vascular medicine, the need for an established diagnostic criterion is imperative in order to reduce misdiagnosis and inappropriate treatment. Although MTS has historically been diagnosed by the presence of pathologic features, the use of dynamic imaging techniques has led to a more radiologic based diagnosis. Thus, imaging plays an integral part in screening patients for MTS, and the utility of a wide array of imaging modalities has been evaluated. Here, we summarize the historical aspects of the clinical features of this syndrome. We then provide a comprehensive assessment of the literature on the efficacy of imaging tools available to diagnose MTS. Lastly, we provide clinical pearls and recommendations to aid physicians in diagnosing the syndrome through the use of provocative measures.

Aspiration thrombectomy using a large-size catheter for acute lower extremity deep vein thrombosis

OBJECTIVE

This study retrospectively evaluated the safety and efficacy of aspiration thrombectomy using a large-size catheter for acute lower extremity deep vein thrombosis (DVT).

METHODS

All patients who underwent aspiration thrombectomy using 9F or 10F catheters for acute lower extremity DVT were included and analyzed. Aspiration thrombectomy was performed in all patients. Additional intravenous thrombolysis was performed in patients with residual thrombus, and stent placement was performed in patients with iliac vein compression syndrome.

RESULTS

From October 2010 to September 2013, the study enrolled 68 patients (37 women, 31 men) with a mean age of 61.7 ± 7.8 years (range, 24-86 years). All patients presented with lower extremity swelling and pain, and the duration of symptoms ranged from 1 to 14 days. The DVTs involved popliteal-iliofemoral veins in 29 patients, iliofemoral veins in 31, and iliac veins in 8. Endovascular procedures were performed in all patients with a technical success rate of 100%. Aspiration alone was effective in 47 patients, and additional thrombolysis was required in the remaining 21. An additional stent was required in 32 patients. Significant improvement in presenting symptoms was achieved in all patients after the procedures, with a clinical success rate of 100%. There were no procedure-related or thrombolysis-related complications. The Villalta scores were <5 in 60 patients and from 5 to 9 in four patients. Primary and secondary patency rates were 89.1% (57 of 64) and 96.9% (62 of 64) at 1 year of follow-up.

CONCLUSIONS

Aspiration thrombectomy using a large-size catheter is safe and effective for acute lower extremity DVT.