Catheter-directed Thrombolysis and Stenting in the Treatment of Iliac Vein Compression Syndrome with Acute Iliofemoral Deep Vein Thrombosis: Outcome and Follow-up

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.

Antithrombotic management of patients with deep vein thrombosis and venous stents: an international registry

BACKGROUND

In patients with acute deep vein thrombosis (DVT) treated with catheter-based thrombolysis and venous stenting, poststenting anticoagulant management is uncertain.

OBJECTIVES

To determine the type and duration of antithrombotic therapy used in patients who have received venous stents for treatment of acute lower extremity DVT.

METHODS

We created an international registry of patients with leg DVT from 2005 to 2019 who received venous stents as part of their acute management. We collected data on baseline clinical characteristics and pre-venous and post-venous stent antithrombotic therapy.

RESULTS

We studied 173 patients with venous stents: 101 (58%) were aged ≤50 years, 105 (61%) were female, and 128 (74%) had risk factors for thrombotic disease. DVT was iliofemoral in 150 (87%) patients, and catheter-based treatment was given within 7 days of diagnosis in 92 (53%) patients. After venous stenting, 109 (63%) patients received anticoagulant-only therapy with a direct oral anticoagulant (29%), warfarin (22%), or low-molecular-weight heparin (10%), and 59 (34%) received anticoagulant-antiplatelet therapy. In patients taking anticoagulant-only therapy, 29% received indefinite treatment; in patients on anticoagulant-antiplatelet therapy, 19% received indefinite treatment. Factors associated with combined anticoagulant-antiplatelet therapy vs anticoagulant-only therapy were use of thrombolytic, thrombectomy, and aspiration interventions (odds ratio [OR], 5.11; 95% CI, 1.45-18.05); use of balloon angioplasty (OR, 2.62; 95% CI, 1.20-5.76); and immediate stent restenosis (OR, 7.2; 95% CI, 1.45-5.89).

CONCLUSION

Anticoagulant therapy without concomitant antiplatelet therapy appears to be the most common antithrombotic strategy in patients with DVT and venous stenting. More research is needed to determine outcomes of venous stenting in relation to antithrombotic therapy.

Prevalence and predictors of combined >50% iliocaval venous obstruction and superficial venous reflux in chronic venous insufficiency patients with healed or active venous leg ulcer

OBJECTIVE

The aim of the present study was to investigate the prevalence and predictors of combined >50% iliocaval venous obstruction (ICVO) and superficial venous reflux (SVR) in patients with chronic venous insufficiency (CVI) with a healed (C5) or an active (C6) venous leg ulcer (VLU).

METHODS

We conducted a retrospective review of prospectively collected data from patients with CVI with CEAP (Clinical, Etiology, Anatomy, Pathophysiology) class C5 (healed ulcer) or C6 (active ulcer) with SVR who had been treated at our institution from February 2017 to January 2018. The demographic, clinical, and surgical data and duplex ultrasound and computed tomography venography findings were collected. We used OsiriX MD, version 2.9, software (Pixmeo SARL, Bernex, Switzerland) to measure the vein diameter via multiplanar reconstruction. The prevalence of combined >50% ICVO and SVR was evaluated, and univariate and multivariate analyses were performed to identify the independent predictors of >50% ICVO in patients with CVI and SVR.

RESULTS

A total of 79 limbs from 67 patients were enrolled. The mean age was 59.82 ± 12.86 years, the mean body mass index was 28.68 ± 6.41 kg/m², and 41.8% were men. The prevalence of >50% ICVO in the patients with SVR was 31.6%. Univariate analysis showed a history of deep vein thrombosis (DVT) in the affected leg (P = .001), a VLU in the left leg (P = .033), a history of a recurrent VLU (P = .038), and reversed flow in the superficial epigastric vein (P = .004) were significantly associated with >50% ICVO in patients with CVI and SVR. Multivariate analysis revealed a history of DVT in the affected leg (adjusted odds ratio [aOR], 8.31; 95% confidence interval [CI], 2.29-30.19; P = .001), a VLU in the left leg (aOR, 3.95; 95% CI, 1.18-13.19; P = .026), and a history of a recurrent VLU (aOR, 3.08; 95% CI, 1.02-9.32; P = .047) to be independently associated with combined >50% ICVO and SVR in patients with CVI.

CONCLUSIONS

The prevalence of combined >50% ICVO and SVR in patients with CVI and CEAP C5 or C6 was 31.6%. The independent predictors of combined >50% ICVO and SVR in those with CVI were a history of DVT in the affected leg, a VLU in the left leg, and recurrent VLUs.

Predictors of long-term outcomes after catheter-directed thrombolysis combined with stent implantation in acute deep vein thrombosis secondary to iliac vein compression

The purpose of this study is to analyze predictive factors for long-term clinical outcomes after catheter-directed thrombolysis (CDT) combined with stent implantation for acute deep vein thrombosis (DVT) secondary to iliac vein compression (IVC). A retrospective analysis was performed to review clinical data and follow-up information on 52 patients who underwent CDT combined with stent implantation for acute DVT secondary to IVC from June 2015 to March 2020. Clinical outcomes including stent patency and incidence of postthrombotic syndrome (PTS) were investigated using Kaplan-Meier analysis. All included patients were categorized into 2 groups according to the presence of PTS. Potential risk factors, including age, gender, degree of iliac vein stenosis, time from onset to treatment, dosage of thrombolytic agent, stent extending below the inguinal ligament, and duration of anticoagulation for PTS were evaluated using multivariate logistic regression analysis. Over a median follow-up of 24 months, 4 individuals underwent reintervention due to in-stent stenosis or stent compression. Primary stent patency was 98.1% at 1 month, 94.2% at 6 months, 90.4% at 12 months, and 88.5% at 24 months. Freedom from PTS was 98.1% at 6 months, 84.6% at 12 months, and 75% at 24 months. No treatment-related mortality or morbidity was observed. Based on the development of PTS, 13 patients with PTS were classified into group A and 39 patients without PTS were regarded as group B. Upon multivariate logistic regression analysis, key prognostic factors for PTS were degree of iliac vein stenosis and time from onset to treatment. CDT combined with stent implantation is safe and effective for acute DVT secondary to IVC in the long-term perspective. Severe iliac vein stenosis and longer period from onset to treatment may be associated with a higher risk of PTS.

Pivotal Study Evaluating the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction

Supplemental Digital Content is available in the text.

Background:

Iliofemoral venous obstruction is recognized with increasing frequency as the underlying cause of lower extremity symptoms including edema, pain, skin changes, and, in advanced cases, ulceration. This study sought to evaluate the safety and effectiveness of the Abre venous self-expanding stent system for the treatment of symptomatic iliofemoral venous outflow obstruction.

Methods:

The ABRE Study (A Multi-Center, Non-Randomized Study to Evaluate the Safety and Effectiveness of the Abre Venous Self-Expanding Stent System in Patients With Symptomatic Iliofemoral Venous Outflow Obstruction) is a single-arm, multicenter, prospective study that included 200 subjects from 24 global sites. The primary end points were 12-month primary patency and major adverse events within 30 days. Secondary end points included lesion and procedure success, primary-assisted and secondary patency, major adverse events, stent migration, stent fracture, and quality of life changes. End point-related adverse events and imaging studies were adjudicated by independent clinical events committee and core laboratories, respectively.

Results:

Venous obstruction cause was classified as acute deep vein thrombosis (16.5%, 33/200), post-thrombotic syndrome (47.5%, 95/200), or nonthrombotic iliac vein lesion (36.0%, 72/200). The common iliac and external iliac veins were stented in 96.0% (192/200), 80.5% (161/200) of subjects, respectively. Stent implant into the common femoral vein was required in 44.0% (88/200). Primary patency at 12 months was 88.0% (162/184). Four (2.0%) major adverse events occurred within 30 days. Twelve-month primary-assisted and secondary patency were 91.8% (169/184) and 92.9% (171/184), respectively. No stent fractures or migrations were reported. Mean target limb Villalta score decreased from 11.2±5.6 at baseline to 4.1±4.8 at 12 months, and the mean target limb revised Venous Clinical Severity Score decreased from 8.8±4.7 at baseline to 4.3±3.6 at 12 months. Clinically meaningful improvements in quality of life and venous functional assessment scores from baseline were demonstrated through 12 months in all measures.

Conclusions:

Symptomatic iliofemoral venous obstruction can be successfully treated with an Abre venous stent. Study outcomes demonstrated a high patency rate with a good safety profile. Patients demonstrated a significant reduction in clinical symptoms and improvement in quality of life that was maintained through 12-month follow-up.

Registration:

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03038438.

Current Status and Prospect of Stent Placement for May-Thurner Syndrome

Stent implantation has been proven to be safe and has become the first-line intervention for May-Thurner syndrome (MTS), with satisfactory mid-term patency rates and clinical outcomes. Recent research has demonstrated that catheter-directed thrombolysis is the preferred strategy when MTS is combined with deep vein thrombosis after self-expanding stent placement. However, the stent used for the venous system was developed based on the experience obtained in the treatment of arterial disease. Consequently, relatively common corresponding complications may come along later, which include stent displacement, deformation, and obstruction. Different measures such as adopting a stent with a larger diameter, improving stent flexibility, and increasing stent strength have been employed in order to prevent these complications. The ideal venous stent is presently being evaluated and will be introduced in detail in this review.

Common iliac vein stenting for May-Thurner syndrome and subsequent pregnancy

BACKGROUND

For women with left common iliac vein compression (ie, May-Thurner syndrome) who undergo venous stenting and subsequently become pregnant, concerns have been raised regarding a possible compromise of stent patency due to compression from the gravid uterus and the hypercoagulability induced by pregnancy. Only a small body of literature exists on this subject, and limited management guidelines are available. The present study was designed to evaluate the safety of iliac vein stenting for May-Thurner syndrome (MTS) with subsequent pregnancy.

METHODS

Female patients who had undergone common iliac vein stenting at our center who were aged 18 to 45 years and had subsequently become pregnant were identified. A retrospective medical record review of eight eligible patients was conducted, recording the demographics, procedural characteristics, and anticoagulation strategies. The primary outcome evaluated was stent patency.

RESULTS

All eight patients had undergone left common iliac vein stenting for MTS. A total of eight stents were placed, and all demonstrated duplex ultrasound patency throughout pregnancy and postpartum. Seven patients delivered healthy pregnancies, and one experienced a stillbirth. The clinical CEAP (clinical, etiologic, anatomic, pathophysiologic) class remained unchanged or improved from pregnancy to postpartum for all patients. The average age at stent placement was 31 ± 5 years, and the average interval from stent placement to pregnancy was 28 ± 19 months. One patient developed nonobstructive deep vein thrombosis (DVT) of the left femoral vein during pregnancy and was treated with therapeutic enoxaparin. The nonobstructive DVT did not compromise the iliac vein stent. Two patients received low-dose aspirin and prophylactic doses of enoxaparin, one for a history of DVT and factor V Leiden and one for a recent history of fertility treatment. The five remaining patients received no anticoagulation, three received low-dose aspirin, and two received no antiplatelet therapy.

CONCLUSIONS

Common iliac vein stent patency was not compromised by subsequent pregnancy in our eight patients with MTS. Furthermore, the stents remained patent throughout pregnancy in patients receiving a wide range of anticoagulation and antiplatelet treatments, suggesting that no uniform therapeutic threshold exists and treatment should be individualized. For most patients, low-dose aspirin alone or no treatment was adequate. This could have implications for counseling women who require intervention for MTS and are of child-bearing age.

The effect of stent compression on in-stent restenosis and clinical outcomes in iliac vein compression syndrome

Background

To evaluate the effect of stent compression on in-stent restenosis (ISR) and clinical outcomes in patients with iliac vein compression syndrome (IVCS) after iliac vein stenting.

Methods

Fifty patients with IVCS treated with iliac vein stenting (Smart Control, Cordis, USA) between March 2017 and October 2018 were consecutively enrolled in this study. Computed tomography venography (CTV) was performed to assess stent compression and ISR. Based on the degree of stent compression, patients were allocated to a significant stent compression (SSC) group and an insignificant stent compression (ISC) group. The incidence of ISR was analyzed between the SSC and ISC groups. Patients' venous clinical severity scores (VCSSs) and responses to the chronic venous insufficiency questionnaire (CIVIQ) one year after stenting were compared between the two groups to evaluate the clinical improvement of venous insufficiency.

Results

In total, 34% of patients had SSC. There were significant differences in the incidence of ISR (52.9% vs. 21.2%, P=0.023), and in each group, there was one case of stent occlusion (5.88% vs. 3.03%, P=0.999). Patients in the SSC group had a higher VCSS score (8.41±5.92 vs. 3.15±2.87, P=0.04) and a lower CIVIQ score (83.35±8.86 vs. 92.21±4.32, P=0.001).

Conclusions

SSC has a significant effect on the incidence of ISR and the clinical outcomes of venous insufficiency. Thus, a dedicated iliac venous stent with sufficient radial resistive force, crush resistance, and outward radial force is needed to prevent the occurrence of stent compression.

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.

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.

Doppler ultrasound and contrast-enhanced ultrasound in detection of stent stenosis after iliac vein stenting

Background

To compare the diagnostic accuracy of Doppler ultrasound (DUS) with contrast-enhanced ultrasound (CEUS) for detection of iliac vein stent stenosis using multidetector computed tomography venography (MDCTV) as the reference method.

Methods

Patients with iliac vein obstructive disease treated with nitinol stents (Smart Control, Cordis, USA) between January 2016 and December 2017 were consecutively included in this study. DUS, CEUS, and MDCTV were carried out in all patients within one week of each other at 1 year post stenting to investigate the presence of stent compression and in-stent restenosis (ISR).

Results

The study included 139 patients (87 females; mean age 58 ± 15 years). For detecting stent compression, the kappa coefficient between the ultrasound modality of gray-scale imaging and MDCTV was 0.901, indicating very good agreement between these two modalities. ISR was detected in 50, 61, and 65 patients by DUS, CEUS, and MDCTV, respectively. DUS and CEUS (kappa = 0.449) and DUS and MDCTV (kappa = 0.516) had moderate agreement for ISR diagnosis, while for which CEUS and MDCTV (kappa 0.884) had very good agreement. The sensitivity and specificity of DUS and CEUS for diagnosing ISR were 63.1% and 90.8%, 87.8% and 97.3%, respectively.

Conclusions

CEUS is probably superior to DUS in terms of diagnostic accuracy for the follow-up of patients with iliac vein stent stenosis.

Percutaneous endovenous intervention without vena cava filter for acute proximal deep vein thrombosis secondary to iliac vein compression syndrome: preliminary outcomes

The aim is to report the preliminary outcomes of percutaneous endovenous intervention (PEVI) for acute proximal deep vein thrombosis (DVT) secondary to iliac vein compression syndrome (IVCS) without inferior vena cava filter (IVCF) placement. Acute DVT patients who underwent PEVI without IVCF were analyzed retrospectively. PEVI consisted of catheter-directed thrombolysis, manual aspiration thrombectomy, balloon angioplasty and stenting. CT was used to evaluate the left common iliac vein (LCIV). Sixty-two consecutive patients (17 men and 45 women, mean age, 59.4 ± 15.2 years) were enrolled. The compression percentage of the LCIV ranged from 51.7% to 95.2% (median 83.2%). Iliac DVT was present in 7 patients; iliofemoral, in 30 patients; and iliofemoropopliteal, in 25 patients. Complete technical success and clinical improvement were obtained in all subjects without the occurrence of symptomatic pulmonary embolism (PE). Five patients experienced recurrent thrombosis. The primary patency rates at 12 and 24 months were 93.8% and 91.4%, respectively, which remained stable at 36, 48 and 60 months. The secondary patency rates at 12 and 24 months were 95.7% and 93.3%, respectively, and there was no change at 60 months. Although limited, our preliminary results suggested that PEVI without IVCF placement seemed to be safe and effective for acute proximal DVT secondary to IVCS without inferior vena cava thrombosis or symptomatic PE.

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.

Endovascular strategy for deep vein thrombosis caused by a huge uterine myoma accompanied by May-Thurner syndrome: A case report

We report the case of a 71-year-old female presenting with deep vein thrombosis (DVT) of the left lower extremity secondary to a huge uterine myoma, who was successfully managed by hysterectomy and staged endovascular treatment. Her DVT was caused by left common iliac vein compression as a result of both the huge uterine myoma and preexisting May-Thuner syndrome. Although reported to put patients at high risk for DVT, coexisting large uterine myomas and May-Thurner syndrome are considered extremely rare.

Contemporary nationwide trends and in-hospital outcomes of adjunctive stenting in patients undergoing catheter-directed thrombolysis for proximal deep venous thrombosis

OBJECTIVE

Outflow venous stenting as an adjunct to catheter-directed thrombolysis (CDT) is performed to prevent recurrent thrombosis and to reduce the risk of post-thrombotic syndrome. Historical data show that stenting improves outcomes of surgical thrombectomy in patients with iliofemoral deep venous thrombosis (DVT), and recent observational data suggest that stenting improves long-term outcomes of CDT. However, the impact of stenting during CDT on acute safety outcomes is unknown. We sought to investigate the contemporary trends, safety outcomes, and resource utilization of adjunctive stent placement in patients undergoing CDT.

METHODS

Patients with proximal lower extremity and caval DVT were identified within the National Inpatient Sample from January 2005 to December 2013. From this data set, we stratified our patients into three groups: patients who received CDT alone, patients who received CDT plus angioplasty, and patients who received CDT plus angioplasty with stenting. We used an inverse probability treatment weighting algorithm to create three weighted cohorts. Cochran-Armitage test was used to evaluate the trends of stent placement among patients treated with CDT. The primary outcome was a composite end point of all-cause mortality, gastrointestinal bleed, or intracranial hemorrhage.

RESULTS

A total of 138,049 patients were discharged with a principal diagnosis of proximal and caval DVT; 7097 of these patients received CDT (5.1%). From this group, 2854 (40.2%) were treated with CDT alone, 2311 (32.6%) received adjunctive angioplasty alone, and 1932 (27.2%) received adjunctive angioplasty and stent. Adjunctive stenting had a significantly lower rate of primary composite outcome compared with CDT alone (2.7% vs 3.8%; P = .04). Stent placement was associated with a similar length of stay compared with angioplasty and CDT alone groups (6.8 vs 6.9 vs 7.1 days, respectively; P = .94) and higher in-hospital charges ($115,164.01 ± $76,985.31 vs $98,089.82 ± $72,921.94 vs $80,441.63 ± $74,024.98; P < .001).

CONCLUSIONS

This nationwide study suggests that one in four patients undergoing CDT is treated with adjunctive stent placement in the United States. This observational study showed that adjunctive stenting does not adversely affect the acute safety outcomes of CDT; however, it was associated with increased hospital charges.

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.

Trombo flutuante em veias profundas de membro inferior e síndrome de May-Thurner: relato de caso

Free-floating thrombus in the deep venous system has a high potential to cause pulmonary embolization. It can also be found in patients with superficial venous thrombosis (SVT) that extends to a deep vein. There are still no defined criteria for treatments described in the literature, which range from anticoagulation and fibrinolytic treatments with vena cava filter implants, through open or endovascular thrombectomies, to more invasive procedures such as surgical interruption with ligation of the venous system. We present the case of a patient with extensive deep venous thrombosis affecting the iliofemoral-popliteal territory with a floating thrombus extending from the left common iliac vein to the inferior vena cava. Treatment was performed with fibrinolytic therapy delivered with a multiperforated catheter, supplemented with anticoagulation with heparin and daily control angiography. At the end of the treatment, a significant stenosis was identified in the left common iliac vein, and angioplasty was performed with stenting.

Single- versus multiple-stage catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis does not have an impact on iliac vein stent length or patency rates

BACKGROUND

Incomplete venous thrombolysis and residual nonstented iliac vein disease are known predictors of recurrent deep venous thrombosis (DVT). Controversy exists as to whether the number of thrombolysis sessions affects total stent treatment length or stent patency. The goal of this study was to evaluate the outcomes of patients who underwent single vs multiple catheter-directed lysis sessions with regard to stent extent and patency.

METHODS

Consecutive patients who underwent thrombolysis and stenting for acute iliofemoral DVT between 2007 and 2018 were identified and divided into two groups on the basis of the number of treatments performed (one vs multiple sessions). Operative notes and venograms were reviewed to determine the number of lytic sessions performed and stent information, including size, location, total number, and length treated. End points included total stent length, 30-day and long-term patency, and post-thrombotic syndrome (Villalta score ≥5). The χ2 comparisons, logistic regression, and survival analysis were used to determine outcomes.

RESULTS

There were 79 patients who underwent lysis and stenting (6 bilateral interventions; mean age, 45.9 ± 17 years; 48 female). Ten patients (12 limbs) underwent single-stage treatment with pharmacomechanical thrombolysis, and the remaining 69 (73 limbs) had two to four operating room sessions combining pharmacomechanical and catheter-directed thrombolysis. Patients who underwent a single-stage procedure were older and more likely to have a malignant disease. These patients received less tissue plasminogen activator compared with the multiple-stage group (17.2 ± 2.2 mg vs 27.6 ± 11.6 mg; P = .008). Average stent length was 8.8 ± 5.2 cm for the single-stage group vs 9.2 ± 4.6 cm for the multiple-stage group (P = .764). Patients who underwent a single-stage procedure had no difference in average length of stay from that of patients who underwent multiple sessions (8.5 days vs 5.9 days; P = .269). The overall 30-day rethrombosis rate was 7.3%. Two-year patency was 72.2% and 74.7% for the single and multiple stages, respectively (P = .909). The major predictors for loss of primary patency were previous DVT (hazard ratio [HR], 5.99; P = .020) and incomplete lysis (HR, 5.39; P = .014) but not number of procedures (HR, 0.957; P = .966). The overall post-thrombotic syndrome rate was 28.4% at 5 years and was also not associated with the number of treatment sessions.

CONCLUSIONS

Single- vs multiple-stage thrombolysis for DVT is not associated with a difference in extent of stent coverage. Patency rates remain high for iliac stenting irrespective of the number of lytic sessions, provided lysis is complete and the diseased segments are appropriately stented.

Outcomes and predictors of failure of iliac vein stenting after catheter-directed thrombolysis for acute iliofemoral thrombosis

OBJECTIVE

Iliac vein stenting is recommended to treat venous outflow obstruction after catheter-directed thrombolysis for acute iliofemoral deep venous thrombosis (DVT). Data on the outcome of proximal and distal stent extension are limited. Proximal stent extension to the vena cava may obstruct the contralateral iliac vein, whereas distal extension below the inguinal ligament contradicts common practice for arterial stents. The aim of this retrospective study was to assess outcomes and predictors of failure of iliac vein stents and contralateral iliac vein thrombosis, taking into consideration stent positioning.

METHODS

Consecutive patients who underwent thrombolysis and stenting for DVT between May 2007 and September 2017 were identified from a prospectively maintained database. The intraoperative venograms were reviewed for proximal stent placement (covering >50% contralateral iliac vein orifice) and distal placement across the inguinal ligament. End points were ipsilateral DVT recurrence, post-thrombotic syndrome (PTS; Villalta score ≥5), and contralateral DVT. Patients with chronic contralateral DVT or contralateral iliac vein stenting at baseline were excluded from the contralateral DVT outcome evaluation. Survival analysis and Cox regression models were used to determine outcomes.

RESULTS

Of 142 patients lysed, 73 patients (12 bilateral DVTs; mean age, 45.8 ± 17.2 years; 46 female patients) were treated with various combinations of thrombolytic techniques and at least one self-expanding iliac stent (77 stented limbs). Thirty-day recurrence developed in nine (12.3%) patients. The 3-year primary patency and secondary patency rates were 75.2% and 82.2%, respectively. The single predictor for loss of primary patency was incomplete thrombolysis (≤50%; hazard ratio [HR], 7.41; P = .002). Overall, 3 of 12 (25%) stents extending below the inguinal ligament occluded at 1 month, 2 months, and 9 months, respectively. The overall rate of PTS (Villalta score ≥5) in the stented cohort was 14.4% at 5 years. This was predicted by incomplete lysis (<50%; HR, 7.09; P = .040), stent extension below the inguinal ligament (HR, 6.68; P = .026), and male sex (HR, 6.02; P = .041). Of the 17 stents that extended into the contralateral common iliac vein and 58 stents that did not, there were 1 (5.9%) and 5 (8.6%) contralateral DVTs (P = .588) at an average follow-up of 27.4 ± 33.7 and 22.2 ± 22.3 months (P = .552), respectively.

CONCLUSIONS

Iliac stenting after thrombolysis for acute DVT guarantees high patency and low PTS rates, provided adequate thrombus resolution has been achieved before stent placement. Stent placement below the inguinal ligament does not affect the patency but may be associated with a higher PTS rate. Stenting proximal to the iliocaval confluence, although a precipitating factor, may not independently increase the likelihood of contralateral DVT.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Role of May-Thurner Syndrome in Recurrent Thrombosis after Catheter-Directed Thrombolysis of Deep Vein Thrombosis

BACKGROUND

May-Thurner syndrome (MTS) leads to an increased incidence of deep vein thrombosis (DVT). Early thrombus removal decreases the post-thrombotic morbidities. Our aim was to better elucidate the relationship between MTS and venous patency after catheter-directed thrombolysis (CDT).

METHODS

The medical records of all patients who underwent CDT from January 2005 to December 2011 due to acute DVT were reviewed retrospectively. Patient characteristics and clinical variables were evaluated to determine association with vein patency.

RESULTS

A total of 51 male and 31 female with a mean age of 34.9 years were treated with CDT. During a median follow-up of 91.7 months, primary patency and secondary patency of all patients were 79.3% and 87.3%, respectively. The presence of MTS was the only significant predictor factor of patency.

CONCLUSIONS

The residual stenosis caused by MTS is a risk for recurrent DVT and should be treated with stenting to improve the outcome.

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

Objectives:

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

Methods:

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

Results:

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

Conclusion:

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

Studies on the relationship between perforating vein insufficiency and iliac compression syndrome

OBJECTIVE

To study correlation among number(n), diameter (D), and blood reflux time(t) and the left common iliac vein stenosis degree of the expansion of perforating veins, so as to guide the clinical formulation and adjust the treatment plan.

METHODS

Retrospective analysis of 45 PVs patients with left common iliac vein in different degrees of compression in our hospital from 2010 to 2012 was performed. Left common iliac vein was divided into 50%-69%, 70%-99%, 30%-49% and occlusion of the stenosis to avoid the error of the left iliac vein stenosis. Pearson's correlation analysis among the number, diameter, and blood reflux time of perforating veins and left common iliac vein was performed.

RESULTS

Pearson's correlation analysis among the number, diameter, and blood back flow time of perforating veins, and the degree of stenosis was performed, and these results showed that correlation coefficients among the number, diameter, and blood return the PVs between flow time and the degree of stenosis were rp-n = 0.784, rp-d = 0.893, rp-t = 0.845 (P < .001), respectively. The two variables exist positive correlation and correlation was significant.

CONCLUSION

With the increase in left common iliac vein stenosis, the number of perforating veins and the diameter increased, and the time of blood flow were prolonged.

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

OBJECTIVES

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

METHOD AND RESULTS

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

CONCLUSION

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

Midterm Results of Endovascular Treatment for Iliac Vein Compression Syndrome from a Single Center

BACKGROUND

The efficacy of endovascular interventional treatment for iliac vein compression syndrome (IVCS) is not well studied. The purpose of our study was to investigate the clinical outcome of endovascular interventional treatment for IVCS.

METHODS

Data of 68 patients with IVCS, who underwent interventional treatment in our hospital, were analyzed retrospectively. Among these patients, 46 had lower extremity varicose veins. Sixty-five patients underwent stent implantation, and 3 patients underwent simple balloon angioplasty. Fourteen patients had post-thrombotic syndrome (PTS) and 11 patients had acute deep venous thrombosis (DVT). Among these 14 patients with PTS, 12 underwent stent implantation and 2 underwent iliac venous simple balloon angioplasty. On the other hand, 9 of the 11 patients with DVT underwent catheter-directed thrombolysis (CDT) and then stent implantation. Of the remaining 2 patients, one underwent Angiojet Rheolytic thrombectomy (ART) before CDT and the other underwent CDT with simple balloon angioplasty. The stenosis rate of iliac vein and the circumference differences between the affected limb and healthy one were measured before and after operation. These patients were followed up with duplex ultrasound postoperatively.

RESULTS

A total of 75 stents were placed in 65 patients. The diameter and the length of stent were 6 to 14 mm (mean 12.5 ± 2.0 mm) and 40 to 260 mm (mean 82.5 ± 36.9 mm), respectively. CDT with/without ART was performed, using urokinase and/or alteplase, after inferior vena cava filtration in all of 11 patients with DVT, without the recurrence of pulmonary embolism. The difference in iliac venous stenosis was statistically significant ([91.2% ± 8.4%] [70.0% ∼ 100.0%] vs. 3.9% ± 13.0% [0 ∼ 70.0%], P < 0.01). The patency rates at 1-, 3-, 6- months, 1 year, and 2 years were 98.5%, 95.6%, 94.1%, 92.4%, and 90.7%, respectively. Four patients (5.9%) suffered from minor bleeding at puncture point and were successfully treated with compression. However, 1 (1.5%) patient underwent stent implantation of right iliac vein that became complicated due to migration of stent to the right ventricle which was successfully arrested by Amplatz Goose Neck Snare Kit. The incidence of PTS was 10.3% (7/68) during the follow-up at 1 to 24 (mean 18.2 ± 7.7) months.

CONCLUSIONS

Interventional therapy for patients of IVCS is safe and effective. Satisfactory outcomes were obtained for stent placement for IVCS.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Incidence and Risk Factors of Deep Venous Thrombosis in Asymptomatic Iliac Vein Compression: A Prospective Cohort Study

BACKGROUND

Deep vein thrombosis (DVT) may be associated with iliac vein compression. Up to now, the majority of data has come from a retrospective study about the correlation between DVT and iliac vein compression. This prospective study was to determine the incidence of DVT in individuals with iliac vein compression and identify risk factors predictive of DVT.

METHODS

A total of 500 volunteers without symptoms of venous diseases of lower extremities and overt risk factors of deep venous thrombosis between October 2011 and September 2012 in Shijitan Hospital were enrolled in this cohort study. All the participants underwent contrast-enhanced abdominal computed tomography (CT) to evaluate iliac vein compression. Baseline demographic information and degree of iliac vein compression were collected. They were categorized into ≥50% or <50% iliac vein compression group. Ultrasound examination was performed to screen DVT at the time of CT examination and 3, 6, 9, and 12 months after the examination. Primary event was DVT of ipsilateral lower extremity. Correlation between DVT and iliac vein compression was estimated by multivariate Logistic regression after adjusting for age, gender, malignancy, surgery/immobilization, chemotherapy/hormonal therapy, and pregnancy.

RESULTS

In 500 volunteers, 8.8% (44) had ≥50% iliac vein compression and 91.2% (456) had <50% iliac vein compression. Ipsilateral DVT occurred in six volunteers including two in iliofemoral vein, two in popliteal vein, and two in calf vein within 1 year. Univariate analysis showed that the incidence of DVT was 6.8% in ≥50% compression group, significantly higher than that in <50% compression group (0.7%) (χ2 = 12.84, P = 0.01). Patients with malignancy had significantly higher incidence of DVT than those without malignancy (χ2 = 69.60,P< 0.01). Multivariate Logistic regression indicated that iliac vein compression and malignancy were independent risk factors of DVT. After adjustment for malignancy, patients with ≥50% iliac vein compression had 10-fold increased risk of developing DVT (adjusted relative risk [RR] = 10.162, 95% confidence interval [CI]: 1.149-89.865, P = 0.037). In subgroup analysis, patients with malignancy and ≥50% iliac vein compression had 12-fold increased the risk of DVT than those without malignance and ≥50% compression (RR = 12.389, 95% CI: 2.327-65.957, P = 0.003).

CONCLUSIONS

Iliac vein compression is common, but the incidence of DVT is low. Only individuals with ≥50% iliac vein compression or compression combined with other risk factors might have significantly increased the risk of DVT. Further study is recommended to improve prevention strategies for DVT in significant iliac vein compression.

Routine extended follow-up surveillance of iliac vein stents for iliocaval venous obstruction may not be warranted

OBJECTIVE

The purpose of this study was to evaluate outcomes of iliac vein stents placed for iliocaval venous obstruction (ICVO) and to determine if routine follow-up surveillance is warranted on the basis of timing of stent failure.

METHODS

All patients who underwent iliac vein stenting from 2003 to 2015 were identified from a prospectively maintained registry. Demographics of the patients, venous risk factors, prior venous interventions, indications, imaging, anatomic location of the ICVO, operative findings, procedural success, complications, and clinical follow-up were recorded. Clinical and ultrasound surveillance was performed at first postoperative follow-up and at routine subsequent intervals. Continuous data were analyzed with Student t-tests or Mann-Whitney U test, and frequency data were analyzed with χ² analysis or Fisher exact test. Primary patency was analyzed using Kaplan-Meier survival analysis.

RESULTS

Seventy-four limbs in 70 patients who underwent iliac vein stenting for ICVO were identified; 36 limbs (48.6%) were stented for nonthrombotic venous compression (stent-VC), and 38 limbs (51.4%) were stented for venous thrombosis (stent-VT). Twenty-seven limbs (71.1%) of the stent-VT group were treated for acute venous thrombosis requiring lysis followed by stenting for underlying venous lesions. The median number of follow-up visits for the stent-VC and stent-VT groups was two (interquartile range [IQR], 1-4) and two (IQR, 1-3), whereas the mean length of follow-up was 19.6 ± 29.5 months and 19.8 ± 26.5 months (P = .972), respectively. During the first 6 months, one limb (2.8% [n = 36]) in the stent-VC group occluded, whereas 13.2% (5/38) of the limbs in the stent-VT group occluded. In the stent-VT group, 57% of limbs (4 of 7) with acute venous thrombosis requiring thrombolytic therapy had limb occlusion at >6 months (median, 18.1 months; IQR, 16.6-30.1). Overall patency rates for the stent-VC and stent-VT groups were 97.2% (1/36) and 73.7% (10/38) at 36 months (standard error, ≤10%; P = .001), respectively.

CONCLUSIONS

Iliac vein stents placed for nonthrombotic iliac vein compression had statistically higher patency than those placed for venous thrombosis, with few stent failures, all occurring within 6 months. Iliac vein stents placed for venous thrombosis continued with stent failure after 6 months and may benefit from extended surveillance.

Underlying Anatomy and Typing Diagnosis of May-Thurner Syndrome and Clinical Significance: An Observation Based on CT

STUDY DESIGN

Cross-sectional study.

OBJECTIVE

To explore the underlying anatomy of May-Thurner syndrome (MTS) using computed tomography (CT) and discuss its clinical significance for typing diagnosis.

SUMMARY OF BACKGROUND DATA

Because the anatomical position of the corpse cannot fully illustrate the actual clinical situation in vivo, the diversity of MTS has not been fully elucidated yet.

METHODS

We retrospectively analyzed the data of 69 patients with MTS. By CT showing, patients were categorized to simple MTS (sMTS, 22 patients), lumbar degeneration-related MTS (dMTS, 33 patients) and other causes MTS (oMTS, 14 patients); meanwhile, a healthy control group were set. Evaluated indexes were onset age, course of disease, diameter of the iliac vein tunnel (IVTD), lumbar degeneration-related iliac vein compression (IVC), therapeutic effect, and diagnostic cutoff of risk IVTD prone to MTS.

RESULTS

The onset age of sMTS, dMTS, and oMTS were respectively 42.3 ± 6.5 years, 61.5 ± 10.6 years, and 53.1 ± 16.8 years (P < 0.001); courses were respectively 12.1 ± 9.2 days, 22.5 ± 7.6 days, and 6.8 ± 6.7 days (P = 0.002). IVTDs of sMTS, dMTS, oMTS, and the control were respectively 2.52 ± 0.50 mm, 2.29 ± 0.30 mm, 5.93 ± 2.21 mm, and 4.34 ± 1.61 mm (P < 0.001). Lumbar degeneration-related IVC in dMTS occurred at 41 places, including forward bulging or protruding intervertebral discs (51%,17/33), osteophytes (50%,16/33), and spondylolisthesis (19%, 8/33), but none happened in sMTS, oMTS, and the control. Eighty-six percent of sMTSs, 55% dMTSs, and none oMTSs needed intravenous stent-implanted operation to obtain effective treatment. MTS type (Waldχ = 6.092, P = 0.009), course (Waldχ = 4.618, P = 0.032), and treatment plan (Waldχ = 14.748, P < 0.001) markedly influence the therapeutic result. The cutoff of risk IVTD for sMTS and dMTS was 2.98 mm, which diagnostic sensitivity was 90% and specificity 100%.

CONCLUSION

Owing to the distinct pathoanatomy and causes, diagnosis in classification of MTS by CT is helpful in accurate treatment program.

LEVEL OF EVIDENCE

3.

Incidence and Outcomes of Inferior Vena Cava Filter Thrombus during Catheter-directed Thrombolysis for Proximal Deep Venous Thrombosis

BACKGROUND

The aim of the study was to retrospectively evaluate the incidence and outcomes of inferior vena cava (IVC) filter thrombus during catheter-directed thrombolysis (CDT) for acute proximal deep venous thrombosis (DVT).

METHODS

From October 2006 to June 2015, patients diagnosed with acute proximal DVT and received CDT after a retrievable IVC filter was placed were included. The incidence, treatment, and outcomes of IVC filter thrombus during CDT were recorded and analyzed.

RESULTS

A total of 189 patients (91 women, 98 men; mean age, 57.6 ± 9.8 years; range, 24-85 years) were included in this study. Among the 189 cases, the DVTs involved popliteal iliofemoral veins in 54 patients, iliofemoral veins in 113 patients, and iliac veins in 22 patients, of which 18 patients had thrombus extended into the IVC. Of the 189 patients, a total of 8 (4.2%, 8 of 189) patients were identified with IVC filter thrombus during CDT. The IVC filter thrombus was detected on a median of 2 days (range, 2-4 days) of CDT therapy, including small-size (n = 6) and large-size (n = 2) filter thrombus. Of the 8 patients, CDTs were performed with a mean 7.6 ± 1.1 days (range, 6-11 days) after the presence of symptoms for the treatment of proximal DVT, and all the IVC filter thrombi were lysed during CDT for the proximal DVT. All the IVC filters were removed successfully with a mean of 12.8 ± 0.93 days from placement. There were no procedure- or thrombolysis-related major complications, and no symptomatic pulmonary embolism breakthrough was seen in any of the patients after the filter placement.

CONCLUSIONS

IVC filter thrombus during CDT for the acute proximal DVT is uncommon, and all of them did not need any additional treatment.

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.

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

Background:

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

Methods:

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

Results:

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

Conclusions:

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

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.

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

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