Endovascular Treatment of Iliac Vein Compression (May-Thurner) Syndrome: Angioplasty and Stenting with or without Manual Aspiration Thrombectomy and Catheter-Directed Thrombolysis

Technical Feasibility and Clinical Efficacy of Iliac Vein Stent Placement in Adolescents and Young Adults with May-Thurner Syndrome

PURPOSE

To report technical feasibility and clinical efficacy of iliac vein stent placement in adolescent patients with May-Thurner Syndrome (MTS).

MATERIALS AND METHODS

Single-institution retrospective review of the medical record between 2014 and 2021 found 63 symptomatic patients (F = 40/63; mean age 16.1 years, 12-20 years) who underwent left common iliac vein (LCIV) stent placement for treatment of LCIV compression from an overriding right common iliac artery, or equivalent (n = 1, left IVC). 32/63 (50.7%) patients presented with non-thrombotic iliac vein lesions (NIVL). 31/63 (49.2%) patients presented with deep vein thrombosis of the lower extremity and required catheter-directed thrombolysis after stent placement (tMTS). Outcomes include technically successful stent placement with resolution of anatomic compression and symptom improvement. Stent patency was monitored with Kaplan-Meier analysis at 3, 6, 12, 24, and 36 months. Anticoagulation and antiplatelet (AC/AP) regimens were reported.

RESULTS

Technical success rate was 98.4%. 74 bare-metal self-expanding stents were placed in 63 patients. Primary patency at 12, and 24-months was 93.5%, and 88.9% for the NIVL group and 84.4% and 84.4% for the tMTS group for the same period. Overall patency for the same time intervals was 100%, and 95.4% for the NIVL group and 96.9%, and 96.9% for the tMTS group. Procedural complication rate was 3.2% (2/63) with no thrombolysis-related bleeding complications. Clinical success was achieved in 30/32 (93.8%) and 29/31 (93.5%) patients with tMTS and NIVL groups, respectively.

CONCLUSION

CIV stent placement in the setting of tMTS and NIVL is technically feasible and clinically efficacious in young patients with excellent patency rates and a favorable safety profile.

Long-term integrity of 53 iliac vein stents after catheter-directed thrombolysis

BACKGROUND

Long-term surveillance data on venous stent integrity is sparse. There is limited knowledge on whether duplex ultrasound (DUS) can detect potential stent deformities such as kinking, straightening, and fracture, which may impact long-term patency of the stented veins.

PURPOSE

To assess venous stent integrity after at least five years of follow-up and to establish the efficacy of DUS as surveillance in patients with venous stent.

MATERIAL AND METHODS

A total of 45 patients with acute iliac-femoral deep vein thrombosis (DVT) treated with catheter directed thrombolysis (CDT) and stenting >5 years before follow-up. Stents were evaluated with 3D volume low dose non-contrast computed tomography (CT) and DUS for kinking, straightening, stent fracture, and patency. Results from CT scans and DUS were compared to assess the overall agreement between the methods.

RESULTS

Median follow-up was 13.2 years (mean = 11.2 years; range = 5.2-15.8 years). 3D CT reconstructions showed normal stent configuration in 47 stents (89%). All intact stents were identified by DUS. In the remaining six stents, 3D CT reconstructions showed compression, tapering, kinking, and minor fracture. DUS recognized all stent complications except the minor fracture. Overall agreement between CT and DUS was 98% (kappa = 0.90). Two cases of stent occlusion were found.

CONCLUSION

The long-term physical resilience of iliac vein stents evaluated with 3D CT in patients treated with CDT for iliofemoral DVT was high. Stent deformities were mostly compression, whereas fracture was rarely seen. DUS seems to be sufficient to evaluate venous stent integrity.

Management of May Thurner Syndrome in Pregnant Patients

May Thurner Syndrome contributes to thromboembolic disease and can cause significant morbidity in pregnant patients secondary to exaggerated anatomic relationships and physiologic changes in the hematologic system favoring thrombogenesis. Because this condition is both underrecognized and underreported, management in pregnant and postpartum patients is based on expert opinion without any formal evidence-based guidance. Herein, we review five pregnancies in four patients with May Thurner Syndrome and general management strategies. Through collaborative and multidisciplinary care, patients with May Thurner Syndrome can be safely and successfully managed during pregnancy and the postpartum period with appropriate anticoagulation.

An overview of in-stent restenosis in iliofemoral venous stents

BACKGROUND

Although endovenous stents have been associated with overall low morbidity, they can require reinterventions to correct stent malfunction due to in-stent restenosis (ISR). ISR has often occurred iliofemoral venous stents but has not been well described. It has been reported to develop in >70% of patients who have undergone iliofemoral venous stenting. We sought to provide an overview of ISR in iliofemoral venous stents, including the pathologic, diagnostic, and management considerations and the identification of several areas of potential research in the future.

METHODS

A search of reported English-language studies was performed in PubMed and the Cochrane Library. "In-stent restenosis," "vein," "venous," "iliac," and "iliofemoral" were used as keywords. The pertinent reports included in the present review had addressed the pathology, diagnosis, and current management options for ISR.

RESULTS

ISR refers to the narrowing of the luminal caliber of the stent owing to the development of stenosis inside the stent itself. ISR should be differentiated from stent compression. Two main types of ISR have been described: soft and hard lesions. These lesions respond differently to angioplasty. Stent inflow and shear stress are important factors in the development of ISR. The treatment options available at present include balloon angioplasty (hyperdilation or isodilation), laser ablation, atherectomy, and Z-stent placement.

CONCLUSIONS

Reintervention for ISR should be determined by the presence of residual or recurrent symptoms and not simply by a numeric value obtained from an imaging study. Overall stent occlusion due to ISR is rare, and no role exists for prophylactic angioplasty to treat asymptomatic ISR. The current treatment options for ISR are mostly durable and effective. However, more research is needed on methods to prevent the development of ISR. The role of antiplatelet and anticoagulant agents in the prevention of ISR requires further investigation, with particular attention to unique subset of patients (after thrombosis vs nonthrombotic iliac vein lesions). For high-risk, post-thrombotic patients, anticoagulation can be considered to prevent ISR. The role of triple therapy (anticoagulation and dual antiplatelet therapy) in the prevention of ISR remains unclear.

Combined high-resolution 3D CUBE T1-weighted imaging and non-contrast-enhanced magnetic resonance venography for evaluation of vein stenosis in May-Thurner syndrome

PURPOSE

To explore the feasibility of high-resolution MRI 3-dimensional (3D) CUBE T1-weighted magnetic resonance imaging (MRI) in combination with non-contrast-enhanced (NCE) magnetic resonance venography (MRV) for the assessment of lumen stenosis in May-Thurner syndrome.

METHODS

Twenty-nine patients underwent computed tomography venography (CTV) and high-resolution MRI-CUBE T1, and NCE MRV acquisitions. ANOVA and LSD tests were used to compare the stenosis rate and narrowest and distal diameters of the vessel lumen.

RESULTS

There were no significant differences in the estimated stenosis rate between CTV, CUBE T1, and NCE MRV (p = 0.768). However, there were significant differences in the measured stenosis diameters of the left common iliac vein (LCIV), with CTV giving the largest mean diameter and CUBE had the smallest mean diameter (p < 0.05). The measured normal LCIV diameters did not significantly differ between MRV and CUBE (p = 0.075) but were significantly larger on CTV than on MRV and CUBE (p < 0.05).

CONCLUSIONS

Compared with CTV, a combination of CUBE and MRV could provide an improved assessment of the degree of lumen stenosis in May-Thurner syndrome and demonstrate acute thrombosis. MRI underestimates the diameter of the vessel in comparison with CTV. MRI can be a substitute tool for Duplex ultrasound and CTV.

May-Thurner Syndrome: An Anatomic Predisposition to Deep Vein Thrombosis

May-Thurner syndrome (MTS) is a rare clinical condition caused by extrinsic compression of the left common iliac vein by the right common iliac artery, leading to venous stasis and predisposing to thrombus formation. Here, we present the case of a 39-year-old female with no obviously known other risk factors predisposing to thrombosis who presented with severe left leg pain and swelling for a week. The international normalized ratio was elevated and the venous Doppler study showed extensive thrombosis extending from the left common iliac vein to the common femoral vein and the popliteal vein. She was diagnosed with MTS and treated with catheter-directed mechanical thrombolysis and thrombectomy, along with angioplasty of the left common iliac vein and external iliac vein, with near-complete resolution post-treatment. MTS should be suspected in patients who present with unilateral limb thrombosis regardless of the presence of predisposing factors. Timely management with endovascular procedures is necessary to help prevent other potential life-threatening complications.

Atypical iliac vein compression in patients with symptomatic May-Thurner syndrome

PURPOSE

We aimed to investigate the incidence, etiology, treatment, and clinical course of atypical iliac vein compressions (AIVCs) among patients with May-Thurner syndrome (MTS).

METHODS

A total of 173 patients who presented with MTS were retrospectively analyzed at a single center. Computed tomographic venography (CTV) was used to diagnose MTS. An AIVC was defined as the compression of the left common iliac vein (LCIV) by structures other than the right common iliac artery (RCIA) or the compression of other venous structures in the pelvic cavity instead of the LCIV. The patients with AIVC were categorized into the LCIV compression group (category A) and non-LCIV compression group (category B).

RESULTS

Ten patients with AIVC were identified (5.8%; male/female, 5/5), five in category A and five in category B. The median age of patients was 76 years (range, 51-94 years), and the median follow-up duration was 388 days (range, 12-4694 days). In category A, the LCIVs were compressed by the left common iliac artery (LCIA) (n=2), uterine leiomyoma (n=1), LCIA aneurysm (n=1), and RCIA aneurysm (n=1). In category B, the right common iliac veins were compressed by the RCIA (n=4) and L5 osteophyte (n=1). Endovascular treatment, including balloon angioplasty and stent placement, was performed in six patients, three from each group. Three patients underwent conservative treatment due to their advanced age and comorbidities. Endovascular aneurysm repair was performed in one patient with RCIA aneurysm. Follow-up images were available for six patients, and all of them had patent venous flow.

CONCLUSION

The AIVC had an incidence of 5.8% (10/173) among symptomatic MTS patients and wide spectrum of etiologies. Pathogenesis-tailored endovascular treatments are safe and effective.

Endovascular and medical therapy of May-Thurner syndrome: Case series and scoping literature review

INTRODUCTION

May-Thurner syndrome has been recognized as a cause of chronic venous insufficiency and a trigger for venous thromboembolism. There is no consensus about the definition, diagnosis, and therapeutic approach. We are aiming to describe its characteristics and a scoping literature review.

METHODS

A retrospective review of patients with May-Thurner syndrome from March 2010 to May 2018 and scoping literature review were made.

RESULTS

Seven patients were identified. All patients were female with a median age of 36 (20-60) years. The median time from the first symptom to diagnosis was 3.41 (0.01-9) years. The primary clinical presentation was post-thrombotic syndrome (4 patients). Six patients had at least one risk factor for deep venous thrombosis. All patients underwent angioplasty with stent; patients with acute deep venous thrombosis, furthermore mechanic thrombectomy with or without catheter-directed thrombolysis were done. There were three complications (one patient, lymphedema, and two venous stent thrombosis). Scoping review results were descriptively summarized.

CONCLUSION

May-Thurner syndrome has a varied spectrum of clinical presentation, and clinical awareness is paramount for diagnosis. Its principal complication is the post-thrombotic syndrome, which is associated with high morbidity. There is no consensus on the antithrombotic treatment approach.

Self-Expandable Nitinol Stents for the Treatment of Nonmalignant Deep Venous Obstruction

BACKGROUND

Angioplasty with stent placement is a therapeutic option for patients with acute thrombotic, postthrombotic, and nonthrombotic obstruction of the iliofemoral veins or inferior vena cava. Previous studies of steel-alloy stents described variable patency rate across indications.

METHODS

The prospective Swiss Venous Stent Registry includes patients treated with self-expandable nitinol stents for deep venous obstruction. Routine follow-up visits include serial duplex ultrasound for stent patency assessment. The primary outcome was primary stent patency. The secondary outcome was venous thromboembolisms. We studied the rate of stent occlusion and potentially contributing factors.

RESULTS

We included 379 patients: 160 with acute thrombotic, 193 with postthrombotic, and 26 with nonthrombotic deep vein obstruction. The mean age was 46±18 years; 55% were women. The cumulative 3-year primary patency rate was 80.5% (95% CI, 73.0%-88.0%) for acute thrombotic, 59.2% (95% CI, 50.4%-68.0%) for postthrombotic, and 100% for nonthrombotic obstruction (log-rank, P<0.0001). Annualized rates of stent occlusion or venous thromboembolism were 7.8 (acute thrombotic), 15.0 (postthrombotic), and 0 (nonthrombotic) events/100 patient-years. In a multivariable Cox regression model, postthrombotic femoral veins at baseline (hazard ratio, 2.64 [95% CI, 1.53-4.56]) and the number of stents (hazard ratio, 1.22 [95% CI, 1.06-1.40]) were associated with stent occlusion after conditioning for age, sex, and clinically relevant factors.

CONCLUSIONS

The rate of stent occlusion (patency loss) and venous thromboembolism varies substantially across indications, also with dedicated venous nitinol stents. Patients with postthrombotic femoral veins and those who received multiple stents were characterized by the highest risk. Registration: URL: https://clinicaltrials.gov. Unique identifier: NCT02433054.

Clinical Outcomes of May-Thurner Syndrome in Pediatric Patients: A Single Institutional Experience

Introduction  May-Thurner syndrome (MTS) is a vascular anatomic variant resulting in compression of the left common iliac vein by the right common iliac artery, affecting approximately 22% of the population. In adults, following acute deep vein thrombosis (DVT) of the iliofemoral veins, the incidence of postthrombotic syndrome (PTS) and recurrent DVT are high if treated with anticoagulation alone, warranting adjunctive treatment with thrombolysis and stent placement. However, there is paucity of literature documenting the course of treatment and associated outcomes in pediatric patients with MTS. Methods  A retrospective chart review of pediatric patients (≤ 18 years of age) with radiologic confirmation of MTS with or without DVT evaluated and/or treated at our institution from January 1, 2005 through December 31, 2015 was conducted. Results  Seventeen patients (4 male; 13 female) were identified. Median age was 15.4 years (range 8.8-17.1 years) with a median follow-up of 1.2 years (range 0.4-7.5 years). Thirteen (76.5%) patients presented with left lower extremity DVT. Management included catheter-directed thrombolysis ( n  = 5), systemic thrombolysis ( n  = 1), and mechanical thrombectomy ( n  = 1). Fifteen patients were treated with anticoagulation including two patients with endovascular stents without DVT. Median duration of anticoagulation was 6.3 months (range 3.2-18.7 months). Ten patients (59%) underwent stent placements. Complete and partial thrombus resolution was noted in six patients each and no resolution in one patient. Four patients had recurrence/progression of thrombus ( n  = 3 with stents) at a median time of 29 days (range 12-495 days). No bleeding complications were observed. Clinically documented or self-reported PTS was noted in 8 patients (62%). Conclusion  There are no clear guidelines for MTS management in children and adolescents. In our cohort, thrombolysis, anticoagulation, or stent placements were not associated with bleeding risks, with recurrence/progression of DVT and signs and symptoms of PTS noted in 30 and 62%, respectively. Further studies are needed to determine a standardized treatment approach of the pediatric patient with MTS with or without thrombosis.

Association between deep vein thrombosis and stent patency in symptomatic iliac vein compression syndrome: Systematic review and meta-analysis

BACKGROUND

The study intended to evaluate stent primary patency rates for patients with iliac vein obstruction related with iliac vein compression syndrome according to clinic presentation.

METHODS

A systematic review and meta-analysis was conducted of studies that compared: unexposed patients with nonthrombotic iliac vein lesion (NIVL, group 1) vs exposed patients with iliac acute deep vein thrombosis (DVT, group 2); and NIVL (group 1) vs exposed patients with iliac vein obstruction and post-thrombotic syndrome (PTS, group 3). The following databases were searched: EMBASE, PubMed, Web of Science, Scopus, SciELO, and LILACS. Two reviewers independently selected the potential studies and extracted data. The pooled odds ratio (OR) and 95% confidence interval (95% CI) are shown for each outcome.

RESULTS

Five studies with a total of 1050 participants and 1169 lower limbs were included. Five hundred eighty-eight lower limbs presented NIVL (50.3%), 91 lower limbs presented acute DVT (7.7%), and 490 lower limbs presented PTS (42%). The endovascular technical success rate of stenting did not differ in any of the groups: 99.6% in NIVL, 94.5% in acute DVT, and 96.5% in PTS (P = .0632). The primary stent patency rates in the 6-month follow-up were 98.3% in NIVL vs 90.9% in PTS, with a statistical difference showing reduced stent patency rates in PTS (OR, 0.17; 95% CI, 0.06-0.48; P = .0008; I² = 0%), and 100% in the NIVL group vs 91.6% in acute DVT, with no statistical difference (OR, 0.30; 95% CI, 0.06-2.32; P = .30; I² = 0%). The primary stent patency rates in the 12-month follow-up were 94.6% in NIVL vs 84.1% in PTS, with a statistical difference showing decreases stent patency rates in the PTS group (OR, 0.29; 95% CI, 0.14-0.63; P = .0008; I² = 0%), and 91.1% in NIVL vs 90.9% in acute DVT, with no statistical difference (OR, 1.03; 95% CI, 0.26-4.07; P = .96; I² = 0%).

CONCLUSIONS

There is no statistical difference for the stent primary patency rates when the treatment is conducted in NIVL as compared with acute DVT lower limbs (at 6 and 12 months); therefore, other criteria must be considered for the indication of this treatment in NIVL patients. However, because there were better results of stent primary patency rates for NIVL vs PTS patients, this finding favors the treatment of acute DVT instead of PTS in lower limbs, once PTS renders smaller stent patency rates at 6 and 12 months.

Deep vein thrombosis due to May-Thurner syndrome: a case report

Background

May-Thurner syndrome (MTS) or Cockett’s syndrome is a rare clinical syndrome, which refers to the compression of the left common iliac vein (LCIV) by right common iliac artery and vertebral body. Complications of MTS include deep vein thrombus formation and even life-threatening pulmonary embolism.

Case presentation

Here, we report the case of a 60-year-old female patient with a complaint of swelling in the left lower limb and pain for 5 days. Computed tomography angiography indicated MTS, and thrombus formation of left external iliac vein and femoral vein. The patient was diagnosed with deep venous thrombosis (DVT) and MTS. The patient underwent ascending venography from the lower extremity to inferior vena cava (IVC) and then to the pulmonary artery with IVC filter implantation, left iliac vein balloon plasty, and stent placement. The patient visited the hospital for the removal of IVC filter, 28 days after the operation. After the interventional therapy, the patient had no in-stent restenosis and had remission during the 2-year follow-up.

Conclusions

This case presents a successful management of MTS in presence of DVT. Although clinicians are rarely aware, the presence of unilateral lower limb swelling and thrombosis may be the manifestations of MTS.

A case of May-Thurner Syndrome: An old anomaly but, a new suggestion: A case report

May-Thurner syndrome (MTS) is an anatomical condition resulting in compression of the left common iliac vein between the right common iliac artery and the underlying spine. MTS is rarely diagnosed because diagnostic workup is seldom continued once the diagnosis of a deep vein thrombosis (DVT) has been established. Furthermore, patients with DVT generally have several well-known confounding risk factors. We report a 16-year-old girl with a history of left leg swelling who was incidentally diagnosed with MTS. We hope that our case report will create awareness of vascular abnormalities in sports medicine and suggest that routine venous Doppler ultrasound screening may help to detect MTS or associated anatomical prior to the formation of early thrombosis.

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.

The clinical outcome of a one-stop procedure for patients with iliac vein compression combined with varicose veins

BACKGROUND

Primary iliac vein compression syndrome (IVCS) often is manifested with varicose veins (VVs), but the treatment of patients with IVCS combined with VVs remains unclear. The aim of this study was to investigate the outcome of a one-stop procedure for patients with IVCS and VVs.

METHODS

The 32 enrolled patients underwent iliac stenting first and then endovenous laser ablation for VVs. The reflux time of the femoral vein, peak reflux velocity, and mean flow velocity were measured, and the effect on quality of life was also assessed using the Aberdeen Varicose Vein Questionnaire and Venous Clinical Severity Score. All clinical data have been recorded and analyzed.

RESULTS

The success rate of the procedures was 100%. No serious complications occurred. The Aberdeen Varicose Vein Questionnaire score and Venous Clinical Severity Score of patients were significantly lower at 1 month, 6 months, and 12 months after the procedure compared with scores before the procedure (P < .01). The reflux time and peak reflux velocity were lower at 6 and 12 months after the procedure (P < .01), and the mean flow velocity was higher at 6 and 12 months after the procedure (P < .05). The patency rate of the iliac vein stent was 100% during follow-up, and one patient (3.13%) had a restenosis without symptoms.

CONCLUSIONS

The one-stop procedure for patients with IVCS combined with VVs is a safe and effective method that might be a therapy choice for these patients.

Manual aspiration thrombectomy for acute and subacute inferior vena cava thrombosis and lower extremity deep venous thrombosis

Deep vein thrombosis (DVT), which can lead to pulmonary embolism (PE), is a major contributor to the global disease burden and is the third most common cardiovascular pathology after coronary artery disease and stroke. Venous thromboembolic disease, which encompasses the disease entities of DVT and PE, affects up to 10 million cases every year and represents a serious and potentially life-threatening condition. Standard anticoagulation therapy alone is ineffective at promoting deep venous system thrombus removal. Many patients develop postthrombotic syndrome (PTS) despite being on adequate anticoagulation therapy. Aggressive therapy for rapid thrombus removal is important to prevent the development of PTS. Besides impeding the onset of PTS, rapid clearance of the thrombus is also required in the treatment of phlegmasia cerulea dolens, an uncommon but life-threatening complication of acute DVT that can lead to arterial insufficiency, compartment syndrome, venous gangrene, and limb amputation. Manual aspiration thrombectomy (MAT) can provide rapid and effective therapy that could be compared to the open surgical thrombectomy approach with minimal risk of morbidity, mortality, or recurrence after surgery. Though many devices have been developed to date for pharmacomechanical thrombolysis, the cost of the treatment using these devices is very expensive. MAT is simple to perform, easy to learn, inexpensive, and rapid. This review will outline and dissect several studies and case reports, sourced from the PubMed database, on the subject of the use of MAT in treating inferior vena cava thrombosis and lower extremity DVT, including in patients with compression of the iliac vein and phlegmasia cerulea dolens.

Early Venous Stent Failure Predicted by Platelet Count and Neutrophil/Lymphocyte Ratio

BACKGROUND

Inflammation and platelet activation have been shown to be involved in acute thromobogenicity following venous occlusive conditions. The aim of this study was to identify the association of baseline platelet count and neutrophil/lymphocyte ratio (NLR) with venous stent failure. Methods and Results: Patients who underwent technically successful iliocaval venous stent placement with available baseline complete blood count and follow-up stent patency data were selected (n=50). Stent failure was defined as >50% stenosis or occlusion at follow-up angiography, contrast-enhanced CT, MRI or duplex US. Median patient age was 49.5 years (range, 13-76 years), and 62% were female. Median follow-up time was 10.2 months (range, 0.1-76.4 months). Stent failure occurred in 13 patients (26%) after a median of 1.2 months (range, 1 day-76.4 months). On multivariable-adjusted Cox modeling, baseline platelets (HR, 2.28; P=0.004) and WBC count (HR, 2.03; P=0.013) were significantly associated with stent failure on follow-up; neutrophils (HR, 16.10; P=0.050); and NLR (HR, 12.19; P=0.050) had borderline significance. Compared with patients without stent failure, those with early, but not late, stent failure had higher baseline platelets (P=0.031) and neutrophils (P=0.025), and NLR (P=0.026).

CONCLUSIONS

Baseline platelet count and NLR are associated with early but not late failure of iliocaval venous stents. This suggests different pathophysiologic mechanisms and a role for both platelet activation and inflammatory mechanisms in early rather than late stent thrombosis. Future research is needed to better explain this novel finding.

Beneficial Effect of Endovascular Treatment on Villalta Score in Japanese Patients With Chronic Iliofemoral Venous Thrombosis and Post-Thrombotic Syndrome

BACKGROUND

Post-thrombotic syndrome (PTS), the most common complication of deep venous thrombosis (DVT), develops in ≥50% of patients with iliofemoral DVT. However, the benefit of endovascular treatment in Japanese patients with chronic DVT and PTS remains unclear. Methods and Results: Between June 2014 and May 2016, endovascular treatment was performed in 11 consecutive Japanese patients with chronic iliofemoral DVT and PTS refractory to anticoagulant therapy and elastic compression stockings. We evaluated the technical success rate, complications, patency, Villalta score, calf circumference, and popliteal vein reflux in both the acute stage (the day following endovascular treatment) and chronic stage (after 6 months). Imaging follow-up included venous duplex scanning and/or magnetic resonance venography. The technical success rate was 81.8%, without complications. In patients with successful intervention, the Villalta score improved significantly, from 9.0±3.7 preoperatively to 3.6±2.5 in the acute phase (P<0.01) and 2.9±2.1 in the chronic phase (P<0.001). The bilateral difference in lower thigh circumference also improved significantly, from 2.6±1.0 cm preoperatively to 1.4±1.0 cm in the chronic phase (P<0.001). However, popliteal vein reflux did not improve. In patients with successful intervention, venous patency rate was 100% at 6 months post-intervention.

CONCLUSIONS

Endovascular treatment is safe and effective in Japanese patients with chronic iliofemoral DVT and PTS.

Endovascular treatment of post-thrombotic and non-thrombotic iliofemoral venous outflow obstructions with self-expanding nitinol stents

BACKGROUND

The aim of the study was to investigate venous patency and clinical outcomes for endovascular treatment of iliofemoral venous obstruction in patients with post-thrombotic syndrome (PTS) and non-thrombotic iliac vein lesion (NIVL) with dedicated self-expanding nitinol stents.

PATIENTS AND METHODS

Data were collected from the prospective Swiss Venous Stent Registry, enrolling consecutive patients with a standardized follow-up procedure since January 2008. Patency was evaluated by duplex sonography and clinical outcome by various scores including the Villalta score at baseline, three, six, and 12 months, and then annually after endovascular therapy.

RESULTS

Overall, 93 patients (64 PTS, 29 NIVL) were analysed. Mean follow-up time was 20 ± 16 (range 3-70) months. A total of 11 (12 %) patients had a stent occlusion, all of which occurred in the PTS group, and 13 (14 %) patients had a symptomatic stent stenosis. Primary patency was 79 % (95 % CI 68-87 %) at 12 months and 72 % (95 % CI 59-82 %) at 24 months. In PTS patients, primary patency at 12 months was 75 % (95 % CI 61-84 %) vs. 89 % (95 % CI 63-97 %) in NIVL patients (p = 0.10). Secondary patency at 24 months was 94 % (95 % CI 84-98 %) in PTS and 100 % in NIVL, p = 0.19). Overall, 62 (67 %) patients were free from PTS at the latest follow-up with a Villalta score < 5 points. Predictive factors for the loss of primary patency were stents placed below the inguinal ligament (OR 2.59, 95 % CI, 0.99-6.84, p = 0.05).

CONCLUSIONS

In symptomatic patients with chronic iliofemoral vein obstruction, endovascular therapy with self-expanding nitinol stents was associated with favourable patency rates and clinical improvement in the majority of patients.

Recurrent Iliofemoral Venous Thrombosis in the Setting of May-Thurner Syndrome as the Presenting Symptom of Behcet's Disease

BACKGROUND

Vascular manifestations including pulmonary artery aneurysms and venous thrombosis are seen in up to 14% of patients with Behcet's disease. We report a patient who had recurrent deep vein thrombosis (DVT) as the presenting symptom of Behcet's Disease.

METHODS

A 19-year-old male who presented with acute iliofemoral DVT, confirmed by intravascular ultrasound (IVUS) and venogram. May-Thurner syndrome was also observed. Repeated catheter-based pharmacomechanical thrombolysis, thrombectomy, and subsequent iliac vein stenting were performed. The patient was then discharged on rivaroxaban and aspirin.

RESULTS

Five months later, the patient experienced left calf pain. In the interim, he had been diagnosed with Behcet's disease by a rheumatologist who was consulted due to oral ulcers and skin lesions and accordingly started on prednisone, colchicine, and azathioprine. At this time, IVUS and venogram revealed thrombotic occlusion of the previously placed stent. Tissue plasminogen activator was infused into the stent, and pharmacomechanical thrombectomy restored flow through the left iliac veins. Follow-up laboratory workup revealed that subtherapeutic azathioprine dosing, and after appropriate adjustment, the patient has been asymptomatic for 12 months.

CONCLUSIONS

Acute refractory DVT is a possible presenting symptom of Behcet's disease, which may be complicated by May-Thurner syndrome. Such patients should receive therapeutic immunosuppression in addition to anticoagulation.

Investigation of adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents in the iliac vein: insights into developing a better iliac vein stent

We analyzed the adverse events associated with an off-label use of arterial stents and CE-marked iliac vein stents for the treatment of iliac venous thromboembolism and investigated their relationships with the anatomical features of the iliac vein, to gain insights into the development of a better iliac vein stent. Reports of adverse events following the use of stents in the iliac vein were retrieved from the Manufacturer and User Facility Device Experience (MAUDE) database that contain suspected device-associated complications reported to the Food and Drug Administration. Data from 2006 to 2016 were investigated. The literature analysis was also conducted using PubMed, Cochrane Library, EMBASE, and Web of Science focusing on English articles published up to 4 October 2016. The analysis of 88 adverse events from the MAUDE database and 182 articles from the literature revealed that a higher number of adverse events had been reported following the use of arterial stents in the iliac vein compared to CE-marked iliac vein stents. While stent migration and shortening were reported only for the arterial stents, stent fracture and compression occurred regardless of the stent type, even though a vein does not pulsate. A study of the anatomical features of the iliac vein implies that bending, compression, and kink loads are applied to the iliac vein stents in vivo. For designing, developing, and pre-clinical testing of stents intended for use in the iliac vein, the above mechanical load environments induced by the anatomical features should be considered.

[Recurrent pain and swelling of the left leg in a 49-year-old male patient]

A 49-year-old male patient presented due to recurrent pain and swelling in the left leg. The patient had had deep venous thrombosis with pulmonary embolism 5 years previously. Since then, he had been treated with Vit-k-antagonists. Pronounced paraumbilical collateral circulation of unknown origin was striking. Doppler sonographic evaluation pointed to May-Thurner syndrome. This was confirmed by phlebography. Venous stenting of the stenosis in the left iliac vein achieved long-term symptom improvement. This case report is intended to draw attention to the rare May-Thurner syndrome as an important differential diagnosis of deep vein thrombosis and, at the same time, identify diagnostic and therapeutic treatment strategies.

New Vein Compression Entities in Patients with Unexplained Leg Swelling

BACKGROUND

This retrospective study identifies often overlooked anatomical sites for nonthrombotic venous outflow obstruction (NTVO) in patients with unexplained lower extremity edema and pain.

METHODS

We reviewed the charts of 75 consecutive patients experiencing symptoms of unexplained lower extremity edema with pain that were unexplained by ultrasound, computed tomography angiography (CTA), and magnetic resonance imaging (MRI), who subsequently underwent venography in an outpatient medical office from 2010 to 2014. We categorized venograms based on the presence or absence of NTVO lesions and calculated prevalence of each at specific sites. The patients with NTVO lesions showing >50% stenosis on venography were then treated with angioplasty and/or stenting. After intervention, we documented subjective levels of pain and edema.

RESULTS

Of the 75 venograms reviewed, physicians classified 52 as normal and 23 as showing evidence of compression, including 9 with May-Thurner syndrome and 14 with anatomical compressions at previously underreported sites. These 14 compression sites occurred at the following: iliofemoral vein at the inguinal ligament region (n = 7, 50%), external iliac vein at the iliac artery bifurcation (n = 1, 7.1%), both inguinal ligament region and iliac artery bifurcation (n = 4, 28.6%), and popliteal vein at the popliteal fossa (n = 2, 14.3%). Nine of the 14 patients (64.3%) reported total or near total resolution of lower extremity pain and edema at follow-up between 1 and 7 months (mean = 5.3 ± 2 months, median = 6 months) after balloon angioplasty and/or stent. Five with failed primary interventions underwent subsequent stenting and/or angioplasty and reported total or near total resolution of pain and clinical resolution of edema.

CONCLUSIONS

This study provides evidence to broaden the disease profile of venous compression syndromes to other sites such as the hypogastric artery, inguinal ligament, and popliteal fossa. The results support previous research that suggests increased incidence of NTVO exists among patients with unexplained lower extremity edema and pain. In an effort to encourage further exploration, we developed a diagnostic algorithm to support a critical and systematic review of patients with lower extremity edema and pain that may go unexplained using traditional diagnostic measures, including ultrasound, CTA, and MRI alone.

Pediatric Thrombolysis: A Practical Approach

The incidence of pediatric venous thromboembolic disease is increasing in hospitalized children. While the mainstay of treatment of pediatric thrombosis is anticoagulation, reports on the use of systemic thrombolysis, endovascular thrombolysis, and mechanical thrombectomy have steadily been increasing in this population. Thrombolysis is indicated in the setting of life- or limb-threatening thrombosis. Thrombolysis can rapidly improve venous patency thereby quickly ameliorating acute signs and symptoms of thrombosis and may improve long-term outcomes such as postthrombotic syndrome. Systemic and endovascular thrombolysis can result in an increase in minor bleeding in pediatric patients, compared with anticoagulation alone, and major bleeding events are a continued concern. Also, endovascular treatment is invasive and requires technical expertise by interventional radiology or vascular surgery, and such expertise may be lacking at many pediatric centers. The goal of this mini-review is to summarize the current state of knowledge of thrombolysis/thrombectomy techniques, benefits, and challenges in pediatric thrombosis.

Patency and Clinical Outcomes of a Dedicated, Self-Expanding, Hybrid Oblique Stent Used in the Treatment of Common Iliac Vein Compression

Purpose: To investigate the clinical outcomes of a dedicated hybrid oblique nitinol stent that has been specifically designed to treat common iliac vein compression. Methods: The Bern Venous Stent Registry database was interrogated to identify all patients who had at least 6-month follow-up after treatment with the sinus-Obliquus hybrid stent for common iliac vein compression. The search identified 24 patients (mean age 39±18 years; 20 women) who matched the search criteria. Ten patients had postthrombotic syndrome (PTS), another 10 patients had acute iliofemoral thrombosis after catheter-directed therapy, and 4 patients had nonthrombotic iliac vein compression. Primary treatment success was defined as antegrade flow and stenosis <30% on venography and evidence of a spontaneous Doppler signal in the treated segment. Stent patency was assessed using duplex ultrasound. Clinical outcomes were evaluated using a clinical symptom score (Villalta) and the revised venous clinical severity score (rVCSS) at 3, 6, and 12 months in follow-up. Results: Primary treatment success was achieved in all patients. Mean follow-up was 10±3 months. Primary patency estimates by Kaplan-Meier analysis were 92% at 6 months [95% confidence interval (CI) 71% to 98%] and 83% (95% CI 54% to 95%) at 10 months. Three symptomatic patients underwent reintervention for early and late stent thromboses and the third for in-stent restenosis, resulting in secondary patency of 100%. Overall, all patients had clinical improvement at the latest follow-up; 50% reported complete resolution of symptoms. In patients with PTS, the Villalta score decreased by 6±6 points (p=0.02) and the rVCSS score by 3±1 points (p=0.05). Among deep vein thrombosis patients, none developed PTS. Conclusion: In patients with common iliac vein compression, the oblique hybrid nitinol stent appears to provide excellent early patency and clinical outcomes.

Endovascular Management of May-Thurner Syndrome: A Case Report

May-Thurner syndrome (MTS) is caused by venous occlusion because of compression of the iliac vein by the iliac artery and vertebral body, leading to left lower extremity deep venous thrombosis, eventually resulting in a series of symptoms. Endovascular treatment has now become the most preferred method of treatment of MTS. The authors report a 66-year-old woman who was hospitalized because of increasing swelling in her left lower limb for almost 2 weeks. Ultrasonography performed upon admission indicated MTS, and venography revealed occlusion of the left common iliac vein and massive thrombosis in the left external iliac and femoral veins. The left lower extremity venous blood flow returned to normal after the patient underwent manual aspiration thrombectomy using a guide catheter, followed by balloon angioplasty and stent placement. The patient achieved complete remission after 1 week and had no in-stent restenosis during the 1-year follow-up. Endovascular treatment is a safe and effective treatment of MTS.

How I treat catastrophic thrombotic syndromes

Catastrophic thrombotic syndromes are characterized by rapid onset of multiple thromboembolic occlusions affecting diverse vascular beds. Patients may have multiple events on presentation, or develop them rapidly over days to weeks. Several disorders can present with this extreme clinical phenotype, including catastrophic antiphospholipid syndrome (APS), atypical presentations of thrombotic thrombocytopenic purpura (TTP) or heparin-induced thrombocytopenia (HIT), and Trousseau syndrome, but some patients present with multiple thrombotic events in the absence of associated prothrombotic disorders. Diagnostic workup must rapidly determine which, if any, of these syndromes are present because therapeutic management is driven by the underlying disorder. With the exception of atypical presentations of TTP, which are treated with plasma exchange, anticoagulation is the most important therapeutic intervention in these patients. Effective anticoagulation may require laboratory confirmation with anti–factor Xa levels in patients treated with heparin, especially if the baseline (pretreatment) activated partial thromboplastin time is prolonged. Patients with catastrophic APS also benefit from immunosuppressive therapy and/or plasma exchange, whereas patients with HIT need an alternative anticoagulant to replace heparin. Progressive thrombotic events despite therapeutic anticoagulation may necessitate an alternative therapeutic strategy. If the thrombotic process can be controlled, these patients can recover, but indefinite anticoagulant therapy may be appropriate to prevent recurrent events.