Interventional treatment for post-thrombotic chronic venous obstruction: Progress and challenges

Chronic venous obstruction, including nonthrombotic iliac vein lesions and post-thrombotic syndrome, presents a significant burden on patients' quality of life and health care systems. Venous recanalization and stenting have emerged as promising minimally invasive approaches, yet challenges in patient selection, procedural techniques, and long-term outcomes persist. This review synthesizes current knowledge on the interventional treatment of post-thrombotic syndrome, focusing on the evolution of endovascular techniques and stenting. Patient selection criteria, procedural details, and the characteristics of dedicated venous stents are discussed. Particular emphasis is given to the role of inflow and other anatomical considerations, along with postoperative management protocols for an optimal long-term outcome.

Criteria to predict midterm outcome after stenting of chronic iliac vein obstructions (PROMISE trial)

BACKGROUND

Endovenous stent placement has become a first-line approach to prevent post-thrombotic syndrome in patients with chronic post-thrombotic obstruction (PTO) or nonthrombotic iliac vein lesions if conservative management fails. This study aims to identify factors associated with loss of patency to facilitate patient selection for endovenous stenting.

METHODS

We retrospectively analyzed 108 consecutive patients after successful endovenous stenting for chronic vein obstruction performed at a single institution from January 2008 to July 2020. Using multivariable logistic regression, we explored potential predictive factors for loss of stent patency, including baseline demographics, post-thrombotic changes, and peak flow velocities measured in the common femoral vein (CFV), deep femoral vein, and femoral vein (FV) using duplex ultrasound examination.

RESULTS

The mean follow-up duration was 41 ± 26 months, and participants had a mean age of 47.4 ± 15.4 years with 46.3% women. Ninety (83.3%) patients had PTO and 18 (16.7%) had nonthrombotic iliac vein lesions, predominantly due to May-Thurner syndrome. Loss of patency occurred in 20 (18.5%) patients, all treated for PTO. Comorbidities, side of intervention, and sex did not differ between patients with occluded and patent stents. Stent occlusion was more common with increasing number of stents implanted (P < .001) and with distal stent extension into and beyond the CFV (P < .001). Preinterventional predictive factors for stent occlusion were lower duplex ultrasound peak velocity in the CFV (odds ratio [OR]: 7.52, 95% confidence interval [CI]: 2.54-22.28; P < .001) and FV (OR: 10.75, 95% CI: 2.07-55.82; P < .005), and post-thrombotic changes in the deep femoral vein (OR: 4.51, 95% CI: 1.53-13.25; P = .006) and FV (OR: 3.62: 95% CI: 1.11-11.84; P = .033). Peak velocities of ≤7 cm/s (interquartile range: 0-20 cm/s) in the CVF and ≤8 cm/s (interquartile range: 5-10 cm/s) in the FV were significantly associated with loss of patency.

CONCLUSIONS

Insufficient venous inflow as assessed by low peak velocities in the CFV and FV as well as post-thrombotic findings represent reliable risk predictors for stent occlusions, warranting their inclusion into the decision-making process for invasive treatment of PTO.

[Endovascular Therapy of Chronic Iliofemoral Venous Outflow Obstructions]

Deep vein thrombosis (DVT) is associated with a high cost burden for health care systems because of secondary cost intensive complications like pulmonary embolism and especially the post thrombotic syndrome (PTS). Current standard therapy of anticoagulation for DVT therapy has not changed through the years leaving patients especially with iliofemoral vein thrombus on a high-risk situation for developing PTS. For patients with chronic venous outflow obstruction of the iliac vein system dedicated venous stents and recanalization techniques are today available.

Neue Therapien akuter und chronischer Beckenvenenobstruktionen

Die Inzidenz der tiefen Venenthrombose (TVT) beträgt in Westeuropa 1/1000 Einwohner pro Jahr. Je nach Lokalisation und Ausdehnung der TVT entwickeln 20–83% der Patienten ein postthrombotisches Syndrom trotz einer optimalen Antikoagulation und Kompressionstherapie. Endovaskuläre Thrombektomieverfahren mit Wiedereröffnung der iliofemoralen venösen Strombahn haben das Ziel, mittel- und langfristig ein postthrombotisches Syndrom zu vermeiden. Bei Patienten mit chronischen V.-cava- und Beckenvenenverschlüssen stehen heutzutage spezielle Rekanalisationstechniken mit Einsatz von speziellen venösen Stents zur Verfügung.

Performance of Open and Closed Cell Laser Cut Nitinol Stents for the Treatment of Chronic Iliofemoral Venous Outflow Obstruction in Patients Treated at a Single Centre

OBJECTIVE

A number of dedicated self expanding nitinol stents have been developed for use in the venous system, with both open cell (OC) and closed cell (CC) designs available. Data comparing these different designs are lacking. The objective of this study was to evaluate outcomes in patients treated with open and closed cells for unilateral chronic iliac vein obstruction.

METHODS

A single centre retrospective cohort study was conducted, including all patients treated with a dedicated nitinol venous stent between 2014 and 2019. Stent patency and details of re-interventions (including lysis, venoplasty, reinforcement, extension, arteriovenous fistula formation) were examined in the first post-operative year. Subgroup analysis described outcomes for patients treated with OC and CC stents ending above the inguinal ligament and those who required extension into the common femoral vein. Cox regression analysis was used to identify factors associated with loss of primary patency.

RESULTS

A total of 207 patients were included (OC 100 patients, CC 107 patients). There was no significant difference between the groups for age (OC 42 years, CC 44 years); gender (OC and CC 67% female); presence of post-thrombotic lesions (OC 71%, CC 73%); stenting across the inguinal ligament (OC 58%, CC 56%), or presence of inflow disease (OC 49%, CC 47%). Primary and cumulative patency at 12 months were similar between groups (primary: OC 63%, CC 65%; cumulative: OC 93%, CC 90%). Patients with a CC stent across the inguinal ligament had a greater risk of needing multiple re-interventions at one year compared with those with an OC stent (odds ratio 2.84, 95% confidence interval [CI] 1.16 - 6.9) but overall, the only factor significantly associated with loss of primary patency was inflow vessel disease (hazard ratio 3.39, 95% CI 1.73 - 6.62, p < .001).

CONCLUSION

OC and CC dedicated nitinol venous stents were observed to perform similarly in terms of patency and symptom improvement at one year. Disease of the inflow vessels was the most important factor associated with a loss of stent patency irrespective of stent design.

The Post-thrombotic Syndrome-Prevention and Treatment: VAS-European Independent Foundation in Angiology/Vascular Medicine Position Paper

Importance

The post-thrombotic syndrome (PTS) is the most common long-term complication of deep vein thrombosis (DVT), occurring in up to 40–50% of cases. There are limited evidence-based approaches for PTS clinical management.

Objective

To provide an expert consensus for PTS diagnosis, prevention, and treatment.

Evidence-Review

MEDLINE, Cochrane Database review, and GOOGLE SCHOLAR were searched with the terms “post-thrombotic syndrome” and “post-phlebitic syndrome” used in titles and abstracts up to September 2020.

Filters Were

English, Controlled Clinical Trial / Systematic Review / Meta-Analysis / Guideline. The relevant literature regarding PTS diagnosis, prevention and treatment was reviewed and summarized by the evidence synthesis team. On the basis of this review, a panel of 15 practicing angiology/vascular medicine specialists assessed the appropriateness of several items regarding PTS management on a Likert-9 point scale, according to the RAND/UCLA method, with a two-round modified Delphi method.

Findings

The panelists rated the following as appropriate for diagnosis: 1-the Villalta scale; 2- pre-existing venous insufficiency evaluation; 3-assessment 3–6 months after diagnosis of iliofemoral or femoro-popliteal DVT, and afterwards periodically, according to a personalized schedule depending on the presence or absence of clinically relevant PTS. The items rated as appropriate for symptom relief and prevention were: 1- graduated compression stockings (GCS) or elastic bandages for symptomatic relief in acute DVT, either iliofemoral, popliteal or calf; 2-thigh-length GCS (30–40 mmHg at the ankle) after ilio-femoral DVT; 3- knee-length GCS (30–40 mmHg at the ankle) after popliteal DVT; 4-GCS for different length of times according to the severity of periodically assessed PTS; 5-catheter-directed thrombolysis, with or without mechanical thrombectomy, in patients with iliofemoral obstruction, severe symptoms, and low risk of bleeding. The items rated as appropriate for treatment were: 1- thigh-length GCS (30–40 mmHg at the ankle) after iliofemoral DVT; 2-compression therapy for ulcer treatment; 3- exercise training. The role of endovascular treatment (angioplasty and/or stenting) was rated as uncertain, but it could be considered for severe PTS only in case of stenosis or occlusion above the inguinal ligament, followed by oral anticoagulation.

Conclusions and Relevance

This position paper can help practicing clinicians in PTS management.

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.

Comparison of endovascular strategy versus hybrid procedure in treatment of chronic venous obstructions involving the confluence of common femoral vein

OBJECTIVE

Treatment of extensive chronic venous obstruction (CVO) with post-thrombotic trabeculation involving the common femoral vein with extension into the femoral vein or deep femoral vein remains a challenge and the best treatment technique for such cases is not clear. In the present study, we compared the results of endovascular alone vs endovascular with additional endophlebectomy (hybrid) procedures for such patients.

METHODS

The medical records of 102 consecutive patients (108 limbs) treated between 2015 and 2020 for iliofemoral CVO extending to the femoral confluence were retrospectively reviewed. The patients were divided into two groups: the hybrid procedure (HP) and endovascular treatment (EN) groups. The HP group consisted of those treated with stent implantation and endophlebectomy of the common femoral vein with creation of an arteriovenous fistula. The EN group included those who had undergone stent implantation alone. The patency rates, complications, and clinical outcomes were analyzed.

RESULTS

Of the 102 patients, 47 (49 limbs) were in the EN group and 55 (59 limbs) were in the HP group. The demographics of the two groups were similar with no statistically significant differences in cumulative primary, assisted primary, or secondary patency rates at 36 months (33.7% vs 36.3%, P = .839; 59.8% vs 64%, P = .941; 69% vs 72.7%, P = .851; respectively). The patients in the EN group, however, had better clinical improvement with a lower postoperative complication rate (P = .012), shorter procedure duration (P < .001), and shorter hospital stay (P = .025).

CONCLUSIONS

The EN and HP both provided similar patency rates for patients with CVO extending into the femoral confluence. The endovascular strategy has the benefit of fewer postoperative complications and a shorter procedure duration and hospital stay compared with the HP.

Endovenöse Therapie chronisch venöser Obstruktionen

Bei der chronisch venösen Obstruktion (CVO) liegt ein Abstromhindernis vor, welches eine venöse Hypertension im betroffenen Bein verursacht. Die CVO tritt vornehmlich auf dem Boden eines postthrombotischen Syndroms (PTS) oder eines May-Thurner-Syndroms (MTS) auf. Die CVO kann zu einer deutlichen Einschränkung des täglichen Lebens führen und hat erhebliche sozioökonomische Konsequenzen. Bei der endovenösen Rekanalisation zur Behandlung einer symptomatischen CVO handelt es sich um eine relativ neue therapeutische Option, die mittlerweile generell als Behandlung der ersten Wahl akzeptiert ist. Seit Verwendung spezieller venöser Stents können auch ausgedehntere Befunde, die eine anspruchsvollere Rekonstruktion erforderlich machen, erfolgreich therapiert werden.

Damit nach einer venösen Rekanalisation keine Stase des Blutstroms und ein Primärverschluss auftreten, müssen ein suffizienter Ein- und Ausstrom gewährleistet sein. Zur Verbesserung des Einstroms werden Hybrideingriffe mit Endophlebektomie der Vena femoralis communis und AV-Fistel-Anlage, zur Ausstromverbesserung werden spezielle Rekonstruktionen der Vena-cava-inferior-Konfluenz, z. B. die Skipped-Technik, empfohlen.

Long-term outcome of dedicated venous stents in management of chronic iliofemoral obstruction

OBJECTIVE

To study the long-term outcomes in patients with occlusive Iliofemoral chronic venous insufficiency (CVI) of benign etiology treated by dedicated venous stents (Zilver Vena stents; Cook, Bloomington, Ind) placed at a single center.

METHODS

We performed retrospective analysis of prospectively collected data from 58 patients with symptomatic benign lower limb CVI during the period from January 2013 to October 2020. Patients underwent recanalization using Zilver Vena stents at Ain Shams University hospitals. We excluded patients requiring stenting after intervention for acute deep venous thrombosis, CVI due to malignancy or vascular malformations, previous ipsilateral venous interventions, or CVI due to nonobstructive pathology (reflux). Patients were clinically classified at enrollment by the clinical, etiology, anatomy, pathology class, venous disability score, and Villalta score. Primary, assisted primary, and secondary stent patency were assessed. Patients were followed clinically and by duplex, at 1, 3, 6, 12 months and annually for 5 years.

RESULTS

There were 31 males and 27 females, with ages ranging between 25 and 60 years (mean, 43.84 years). All patients had post-thrombotic syndrome with a mean Villalta score of 16.8 (range, 10-31). Patients were treated with dedicated venous stents and had a median follow-up of 60 months. The median venous disability score was 3 at the start of the study with a significant decrease to 1 at 5-year follow-up (P < .001). Twelve-month primary patency, assisted primary patency, and secondary patency were 91.4%, 96.6%, and 98.3%, respectively. At the 5-year follow-up, primary patency was 60.3%, assisted primary patency 65.5%, and secondary patency 81%. There were no instances of stent fracture, migration, or structural deformities.

CONCLUSIONS

Treating iliofemoral venous occlusive disease with a dedicated venous stent is an excellent choice for patients with occlusive post-thrombotic syndrome. The technique has good 1-year and 5-year patency and is associated with significant clinical improvement and few complications.

Clinical outcomes and overview of dedicated venous stents for management of chronic iliocaval and femoral deep venous disease

OBJECTIVES

Venous stenting of the lower extremities has grown in popularity and is now considered a key component of the primary treatment strategy for the management of pathologically obstructive or stenotic lesions of the deep venous system. This review aims to provide an overview of the role of venous stenting in the management of chronic conditions affecting the deep venous system of the lower limbs.

METHODS

An overview of venous stents design and current role of stenting procedure in individuals presenting with Chronic Venous Insufficiency (CVI) and presenting the current trials of dedicated venous stenting in management of chronic deep venous lesions. This review provides a focused insight on venous stent design, physical properties and the available dedicated venous stents selected studies with their related patency outcome based on selective literature search of the PubMed database and Cochrane library.

CONCLUSIONS

Dedicated venous stent technology is advancing at a rapid pace alongside the increased undertaking of endovascular deep venous stent reconstruction in the management of iliocaval vein pathologies. The ideal design(s) for venous stents remain unknown, although it is hoped that the presence of new dedicated venous stents in clinical practice will allow the generation of experience and data to advance our understanding in this area.

Effect of thrombophilia on clinical outcomes of chronic post-thrombotic patients after iliofemoral stenting with nitinol venous stents

OBJECTIVE

Thrombophilia is a prothrombotic condition that increases the risk of venous thromboembolism. It is unclear whether the presence of thrombophilia alters the clinical outcomes after deep venous stenting. The aim of the present study was to examine the relationship between thrombophilia and outcomes after stenting for post-thrombotic syndrome.

METHODS

Consecutive patients (2012-2017) receiving a nitinol venous stent for chronic post-thrombotic venous occlusive disease with a minimum of 18 months of follow-up in one center using the same anticoagulation protocol were included. The clinical history and thrombophilia testing results were reviewed. The outcomes were stent patency, which was assessed using duplex ultrasonography at 24 hours, 2 and 6 weeks, 3 months, 6 months, and annually thereafter; and reinterventions, which were performed when the stent diameter was <50% or occluded.

RESULTS

Of the 136 patients who had undergone intervention, 55 (40%) had had a provoked deep vein thrombosis (DVT) and 81 (60%) had had an unprovoked DVT and had therefore undergone thrombophilia testing. Of the 81 patients, 38 (47%) had had either inherited (n = 19; 50%) or acquired (n = 19; 50%) thrombophilia. Of the 136 patients who had undergone stenting, 68 had required reintervention (50%) during follow-up to maintain stent patency. Of the 55 patients with a provoked DVT, 29 (53%) had required reintervention. Of the 81 patients with an unprovoked DVT, 39 (48%) had required reintervention (P = .420). Of the 38 patients with unprovoked DVT and thrombophilia, 17 (45%) had required reintervention. Of the 43 patients with unprovoked DVT and no thrombophilia, 22 (51%) had required reintervention (P = .766). The cumulative patency rate was 80% for patients with provoked DVT and 88% for those with unprovoked DVT (P = .193). The presence of thrombophilia was not associated with patency loss (92% cumulative patency for patients with thrombophilia and 84% for patients without thrombophilia; P = .307).

CONCLUSIONS

Using our anticoagulation protocol, patients with and without thrombophilia had similar clinical outcomes after deep venous stenting and should not be excluded from iliofemoral venous stenting. We found no significant differences in outcomes in conjunction with appropriate postoperative anticoagulation therapy.

Postthrombotisches Syndrom auf dem Boden einer chronischen iliofemoralen Thrombose: Therapieoptionen und -limitationen

Ein 49-jähriger Patient stellte sich mit einer langsam progredienten, ca. 7 cm großen Schwellung in der linken Kniekehle vor. Sonografisch und MR-tomografisch zeigte sich das Bild eines postthrombotischen Syndroms am linken Bein mit einem langstreckigen chronischen venösen iliofemoralen Verschluss und ausgeprägten Kollateralen sowie Varixkonvoluten in der linken Kniekehle, die der beklagten Schwellung entsprachen. Es erfolgte die Endophlebektomie der Vena femoralis und Vena femoralis profunda mit einer ventralen Rekonstruktion durch eine bovine Perikard-Patch-Plastik mit Rekanalisation der chronisch okkludierten venösen Iliakalachse mit langstreckiger Stentangioplastie als Hybridoperation. Abschließend wurde eine inguinale AV-Fistel angelegt. Postoperativ entwickelte der Patient einen Frühverschluss der venösen iliofemoralen Strombahn und eine inguinale Lymphfistel. Aufgrund dieser erfolgte zunächst kein operativer, sondern ein perkutaner transjugulärer, letztlich frustraner Rekanalisationsversuch. Die inguinale Heilung benötigte bis zum Sistieren der Lymphexsudation 8 Wochen. Nach diesem Zeitintervall entschieden wir uns aufgrund der zu erwartenden schlechten sekundären Offenheitsrate gegen eine operative Revision, sodass therapeutisch nur die Antikoagulation und Kompression blieb. Die Ursache des dargestellten Frühverschlusses bleibt unklar, mögliche Ursachen und sich daraus ergebende Konsequenzen werden diskutiert.

Use of the VENOVO™ and Sinus Obliquus™ venous stents in the treatment of non-thrombotic or post-thrombotic iliac vein lesions - Short-term results from a multi-centre Asian cohort

OBJECTIVES

Deep venous stenting with intravascular ultrasound (IVUS) guidance is gaining favour as the treatment modality of choice for symptomatic ilio-femoral venous occlusive disease. The aim was to determine the short-term patency and symptomatic relief gained using the Bard Venovo™ and Optimed Sinus Obliquus™ stents in the endovascular treatment of non-thrombotic iliac vein lesions (NIVL) and post-thrombotic venous obstruction (PTO) from two Asian tertiary vascular centres.

METHODS

Sixty patients (males = 21/60 (35.0%); median age 67 years (interquartile range 54-77)) who underwent IVUS interrogation and ilio-femoral stenting (June 2018-May 2019) in two Asian centres were prospectively followed. Clinical improvement was determined by the revised Venous Clinical Severity Score (rVCSS), pain using the Visual Analogue Scale (VAS) and ulcer healing rate. Patency rates were evaluated using Duplex ultrasound and computer tomography venogram.

RESULTS

Seventy-one legs were interrogated and stented; 11/60 (18.3%) patients had a bilateral procedure. Indications for surgery were PTO (n = 11/71 (15.5%)) and NIVL (n = 60/71 (84.5%)). Twenty-seven of 71 (38.0%) patients had CEAP 6 disease. The median follow-up was 283 (interquartile range 211-370) days. Technical and procedural success was both 100%. Twenty-one of 71 (29.6%) legs had a combination of Venovo™ and Sinus Obliquus™ stents inserted for concurrent ilio-caval and iliac lesions. There were no major post-operative complications. Six-month primary, assisted primary and secondary patency rates were 94.1, 97.1 and 100%, respectively. There were no stent fractures. Mean rVCSS and VAS improved from 12.26 (±3.31) to 4.33 (±2.78) and 6.97 (±1.38) to 2.03 (±1.65), respectively, at three months (p < 0.01). Complete ulcer healing was seen in 27/27 (100%) patients at three months.

CONCLUSION

Use of Venovo™ and Sinus Obliquus™ stents for symptomatic ilio-femoral venous disease showed excellent six-month primary patency rate with no stent fractures. There were significant clinical improvement and low-device-related complications. Longer follow-up is awaited to see how these dedicated venous stents perform.

Safety, procedural success and outcome of the Aspirex®S endovascular thrombectomy system in the treatment of iliofemoral deep vein thrombosis – data from the Arnsberg Aspirex registry

Summary. Background: Percutaneous mechanical thrombectomy (PMT) represents a treatment option in addition to conventional therapy for patients with iliofemoral deep vein thrombosis (DVT). We sought to determine the safety, patency and short-term outcome of the Aspirex®S catheter as a rotational mechanical thrombectomy device in the endovascular treatment of iliofemoral DVT. Patients and methods: 56 patients (66 % female, median age 51 years) undergoing mechanical thrombectomy with the Aspirex®S catheter for endovascular treatment of iliofemoral DVT were included in the analysis. Device- and procedure-related complications, prevention of post-thrombotic syndrome (PTS) and patency rates were determined at baseline and at 1, 6 and 12 months after intervention. Results: No device-related complications or malfunction occurred. Procedure-related complications (rehospitalization, re-occlusion of target vein, prolonged hospitalization resulting from access site complication) were seen in 14 % of patients. PMT was followed by implantation of a dedicated venous stent in all patients. Low PTS reflected by a revised venous clinical severity score (rVCSS) of < 3 and a clinical, etiologic, anatomic and pathophysiologic (CEAP) score of < 3 were achieved in 64 % of the patients at 12 months. Patency was 95 % after 1 month, 94 % after 6 months and 87 % after 12 months. Conclusions: Even though long-term studies are missing, PMT of iliofemoral DVT using the Aspirex®S rotational thrombectomy device as a standalone approach exhibited an excellent patency at short term associated with substantial prevention of moderate to severe PTS and low device-related complications including bleeding.

Venovo venous stent in the treatment of non-thrombotic or post-thrombotic iliac vein lesions – short-term results from the Arnsberg venous registry

Abstract. Background: We sought to determine the patency and clinical symptom relief of the Venovo venous stent in the endovascular treatment of non-thrombotic (NIVL) or post-thrombotic venous obstruction (PTO) of the iliofemoral track over a period of 6 months. Patients and methods: A total of 80 patients (45 female, mean age 57 years) treated in 2016 and 2017 were included in the Arnsberg venous registry. Clinical improvement was determined by the revised venous clinical severity score (rVCSS) as well as the clinical, etiologic, anatomic and pathophysiologic (CEAP) score. Primary and secondary stent patency was evaluated using duplex ultrasound. Results: Overall 6-months patency rates were 98 % for primary and 100 % for secondary patency. For NIVL primary patency was 97 %, whereas for PTO primary patency was 96 %. Early stent re-occlusion occurred in 3 patients within 34, 59 and 156 days after intervention. Two of these patients were successfully treated by endovascular mechanical thrombectomy and stent in stent implantation. Clinical improvement with a gain of ≥ 2 rVCSS levels was observed in 51 %. CEAP scores decreased from 4.3 to 2.7. Conclusions: In this first time report the novel Venovo venous stent showed adequate patency rates associated with reasonable clinical improvement and low device-related complications throughout a 6-months-follow-up in both NIVL and PTO.

A novel endovenous scaffold for the treatment of chronic venous obstruction in a porcine model: Histological and ultrastructural assessment

OBJECTIVE

To investigate the biological effects of a novel endovenous scaffold in a porcine model.

METHODS

Petalo is a compliant venous scaffold implanted into the internal jugular veins of 12 healthy pigs. The pigs were sacrificed at one, two, three, and six months, respectively. Microscopic investigations were performed at two blinded laboratories.

RESULTS

Neo-intima formation progressively covering up the stent metallic bars was observed. The inflammatory response of the venous wall showed a peak after three months by the implant, followed by marked reduction after six months. The device induced a significant ( p < 0.01) increase of the thickness respect to the control regions, but was comparable in sections obtained after three and six months.

CONCLUSIONS

The implant of Petalo compliant venous scaffold in the venous wall of this porcine model is characterized by neointima formation and by an inflammatory reaction which tends to decrease after six months. Our data point against the induction of smooth muscle cells proliferation and migration as confirmed by electronic transmission microscopy analyses.

Two Year Outcome After Chronic Iliac Vein Occlusion Recanalisation Using the Vici Venous Stent®

OBJECTIVE/BACKGROUND

The aim was to assess two year outcomes with placement of the Vici Venous Stent^® in patients with chronic iliofemoral venous occlusions (complete blockage).

METHODS

This was a retrospective single centre study comprising patients treated with the Vici Venous Stent for venographically verified iliofemoral venous occlusion and post-thrombotic syndrome (Villalta score ≥ 5 points) at least 12 months after acute deep vein thrombosis. Venography and intravascular ultrasound were used peri-operatively; duplex ultrasound was used to assess stent patency during follow up.

RESULTS

Eighty-eight patients (101 limbs) had stent placement between March 2014 and October 2016. Median pre-treatment Villalta score was 14 (range 5-33). Stenting extended across the inguinal ligament in 63 limbs (62%) in order to land in a healthy venous segment. Six patients (7%) required endophlebectomy and fistula creation. Median imaging follow up was 21 months (range 0-41 months). Primary, assisted primary and secondary patency rates at one year were 59%, 78%, and 87%, respectively, and two years 51%, 73%, and 82%, respectively. Forty-three limbs (43%) had re-intervention (lysis, venoplasty, and/or placement of stent) during follow up; median time to re-intervention was 32 days (range 0-520 days). At 24 months, 37 of 53 limbs (70%) with available Villalta assessment showed clinically significant improvement (>30% reduction of baseline score). Villalta scores at the 6, 12, and 24 month clinical follow up were significantly lower than before stenting (p < .001, all time points). In a subset analyses of limbs with stenting terminating above and below the inguinal ligament, secondary cumulative patency rates at 24 months were 90% and 79%, respectively; clinical outcome showed 58% vs. 73% of limbs with clinically significant improvement, respectively. There was no statistically significant difference in patency or clinical outcomes.

CONCLUSION

The Vici Venous Stent is associated with a good secondary patency rate and durable and substantial symptomatic resolution in patients with chronic post-thrombotic occlusions, regardless of whether stents extended beneath the inguinal ligament.

Standards for recanalisation of chronic venous outflow obstructions

Abstract. Postthrombotic syndrome (PTS) is the most common complication after iliofemoral deep vein thrombosis. It reduces quality of life and increases deep vein thrombosis (DVT)-related costs. The clinical symptoms and severity of PTS may vary; the most common symptoms include edema, pain (venous claudication), hyperpigmentation, lipodermatosclerosis, and ulceration. PTS is based on the principle of outflow obstruction, which may be caused by venous hypertension and may lead to valvular damage and venous reflux or insufficiency. Recent technical developments and new stent techniques now allow recanalisation of even complex venous outflow obstructions within the iliac vein and the inferior vena cava. This manuscript gives an overview on the latest standards for venous recanalisation.

The Treatment of Post-Thrombotic Syndrome

BACKGROUND

Post-thrombotic syndrome (PTS) arises in 20-50% of patients who have sustained a deep vein thrombosis and markedly impairs their quality of life.

METHODS

This review is based on pertinent publications retrieved by a selective literature search in PubMed and the Cochrane Library, and on the guidelines of the German Societies of Phlebology and Vascular Surgery (Deutsche Gesellschaft für Phlebologie, Deutsche Gesellschaft für Gefässchirurgie).

RESULTS

The treatment options are conservative treatment with compression and patient exercises, endovascular recanalization with stent angioplasty, and open bypass surgery of the iliac obstructions. The endovascular techniques yield patency rates of 73 to 100%, with thrombotic stent occlusion and hematoma as potential complications. The open operations have only been documented in studies with small case numbers (3 to 85 cases per study, patency rates 58 to 100%). The complications of these invasive procedures can include thrombotic bypass occlusion, hematoma, and wound infection. There have been randomized trials of conservative treatment, but not of surgical treatment. The American Heart Association, in its guidelines, gives the same weak recommendation for all surgical methods (IIb).

CONCLUSION

All conservative options should be exhausted as the first line of treatment. If PTS symptoms persist and markedly impair the patient's quality of life, the possible indication for surgery should be considered. As PTS hardly ever leads to death or limb loss, its treatment should be as uninvasive as possible. Endovascular recanalization is an attractive option in this respect. A conclusive evaluation of the role of endovascular procedures in PTS must await randomized trials of this form of treatment and of the optimal stent configuration.

Patency rates and clinical outcomes in a cohort of 200 patients treated with a dedicated venous stent

OBJECTIVE

Minimally invasive interventions by recanalization, percutaneous transluminal angioplasty, and stenting in post-thrombotic syndrome (PTS) obstructions and iliac vein compression syndrome (IVCS) have shown good results. Until recently, no dedicated venous stents were available, and stent-related issues accounted for a decrease in patency scores. The introduction of dedicated stents with more flexibility and higher radial forces could result in higher patency scores. This study focused on the outcomes of patients treated by a dedicated sinus-Venous stent (OptiMed GmbH, Ettlingen, Germany). Patency rates and clinical evaluation are described for both PTS and IVCS patients.

METHODS

A total of 200 patients treated at a tertiary university referral center were analyzed. A percutaneous procedure was performed in 103 (51%) PTS patients and 48 (24%) IVCS patients. In 49 (25%) patients, a hybrid procedure was executed. Patency rates and complications were analyzed by duplex ultrasound. Clinical improvement was scored by Venous Clinical Severity Score, Villalta scale, and venous claudication rates.

RESULTS

The mean age was 43.2 ± 14.5 (17-81) years, and 66% were female. Mean Villalta score decreased from 10.5 ± 4.2 (3-24) to 5.3 ± 3.8 (0-14) at the latest follow-up (P < .001). Venous Clinical Severity Score decreased by a total of 3 points (P < .001). At baseline, venous claudication was present in 132 patients, which subsided in 115 (87%). Overall patency scores revealed a primary patency of 68%, assisted primary patency of 83%, and secondary patency of 90% with a median follow-up of 12 (11-12) months. Of all included patients, 122 (61%) did not have a complication during follow-up; the most frequent complications were in-stent restenosis (n = 23) and occlusion (n = 25) of the stented tract.

CONCLUSIONS

Short-term clinical results using the sinus-Venous stent are comparable to previous research. Loss of stent patency due to stent-related issues like kinking or tapering is hardly ever seen in this short-term follow-up.

Detecting stent geometry changes after venous recanalization using duplex ultrasound

Background

Patients with post-thrombotic syndrome due to chronic venous obstruction and resistant to conservative management can benefit from endovenous revascularization. The current study investigated the usefulness of duplex ultrasound in monitoring the stent changes over the time.

Method

All duplex ultrasound images of treated patients were reviewed retrospectively. The stent diameter and area during the follow-up visits have been analyzed.

Result

A total of 210 stents were placed in 137 limbs. Duplex ultrasound findings showed a decrease in area of stent in all patients (mean: 0.69 cm2). Reduction of stent area over the time was a predictor of stent patency (odds ratio: 0.910; confidence interval: 0.832–0.997).

Conclusion

Duplex ultrasound has sufficient accuracy in detection of stent changes and its patency. There is a discrepancy between diameter of the stent lumen in vitro and after deployment in all patients. Stent occlusion is related to reduction of stent lumen over the time rather than the percent of the stenosis.

Haemostaseological complication management in caval and iliac venous stenting

Antiplatelet and anticoagulation therapy after venous stenting is still not standardized, data from randomized-controlled trials are missing. Rare prothrombotic disorders and nonresponsiveness to drugs must be taken into account. This case report demonstrates successful haemostaselogical complication management in recurrent rethromboses due to underlying clopidogrel resistance and low responsiveness to anticoagulation with dabigatran after endovascular stent reconstruction of chronic pelvic and caval vein occlusion in a patient with severe postthrombotic syndrome.

Stent extension into a single inflow vessel is a valuable option after endophlebectomy

Background

Venous stenting with an endophlebectomy and arteriovenous fistula can be performed in patients with extensive post-thrombotic changes. However, these hybrid procedures can induce restenosis, sometimes requiring stent extension, into a single inflow vessel. This study investigates the effectiveness of stenting into a single inflow vessel.

Methods

All evaluated patients had temporary balloon occlusion of the arteriovenous fistula to evaluate venous flow into the stents. When stent inflow was deemed insufficient, AVF closure was postponed and additional stenting was performed. Patency rates and clinical outcomes were evaluated.

Results

Twenty-four (38%) of 64 patients had additional stenting. The primary, assisted primary and secondary patency were 60 %, 70% and 70% respectively. Villalta score reduced by 6.1 points (p < 0.001), and venous clinical severity score by 2.7 points (p = 0.034).

Conclusion

Stenting through the femoral confluence into a single inflow vessel is a feasible bailout option if primary hybrid intervention fails with relative high patency rates and clinical improvement.

Wound complications after common femoral vein endophlebectomy: Influence on outcome

Introduction Venous recanalization of obstructed femoral and iliac veins is associated with good results regarding the feasibility and patency rate. If the common femoral vein with its inflow vessels is involved, open surgical desobliteration or endophlebectomy has been described as a crucial part of the intervention. However, when performing the hybrid procedure, a number of specific complications have been described. We present our results after venous recanalization including an endophlebectomy, focussing on wound complications and its impact on outcome. Material and methods A retrospective analysis of prospective recorded data of all patients who underwent a hybrid procedure for chronic obstruction of iliofemoral veins between 2010 and 2015 was performed. The patients were treated by recanalization of the affected veins combined with endophlebectomy of the common femoral vein and arteriovenous fistula implantation. Data assessment focussed on complications and patency rates. Results This study includes 96 patients, thereof 58 females with a mean age of 44.1 years. The mean procedure time was 344 ± 140 min (range 124-663). Median follow-up time was 12.5 months (2-33 months). Primary patency was 62.5% and secondary patency was 90%. Re-intervention due to early occlusion within the first 30 post-intervention days was necessary in 37.5% of all cases. Besides bleeding complications, wound complications, mainly classified as Szilagyi I, occurred in 33% of all patients. A multivariate analysis showed a significant impact of wound complications on primary as well as secondary patency rate ( p = 0.032, respectively 0.015). Conclusion Recanalization of obstructed iliac veins and/or the inferior vena cava combined with endophlebectomy of the common femoral vein and arteriovenous fistula implantation is a safe and feasible treatment option in the post-thrombotic syndrome. As wound complications are a common and associated with a significant impact on patency rate, further attempts to improve the procedure are crucial.

Interventional treatment of postthrombotic syndrome

BACKGROUND

Postthrombotic syndrome (PTS) is the development of symptoms and signs of chronic venous insufficiency following deep vein thrombosis (DVT) and has a significant negative effect on the quality of life. The current understanding is that the clinical manifestation of PTS is related more to venous obstruction than it is to venous reflux. The use of interventional techniques for the treatment of venous obstruction and/or venous occlusion has rapidly increased in recent years.

OBJECTIVE

This article summarizes the current concept of endovenous and hybrid interventions and presents the optimized treatment of choice in patients with chronic symptomatic venous obstruction.

METHODS

We performed a systematic literature search in the Medline database to identify relevant studies on the treatment of patients with PTS.

RESULTS

A meta-analysis of the relevant studies showed that this minimally invasive procedure is an effective treatment option with low morbidity and no mortality. Use of the newly developed dedicated venous stents showed promising results with good mid-term patency rates and a significant decrease in related symptoms.

CONCLUSION

Interventional therapy for the treatment of symptomatic chronic venous obstruction has become the method of choice in recent years. More studies are needed to evaluate the long-term success rate of dedicated venous stents.

Combination of factor Xa inhibition and antiplatelet therapy after stenting in patients with iliofemoral post-thrombotic venous obstruction

OBJECTIVES

Studies addressing optimal postprocedural pharmacological management after endovascular stenting of iliofemoral post-thrombotic venous obstruction are lacking. We report our early clinical experience with a combination of rivaroxaban and clopidogrel in patients after iliofemoral post-thrombotic venous obstruction stenting.

METHODS

Demographic, procedural, and follow-up data of nine patients (seven women; mean age of 32 ± 11 years) undergoing 10 procedures for iliofemoral post-thrombotic venous obstruction performed between August 2012 and January 2014 were retrospectively reviewed. After endovascular intervention, all patients were administered 20 mg rivaroxaban once daily (s.i.d.) and 75 mg clopidogrel s.i.d. or every second day depending on the individual drug responsiveness for at least six months. The adenosine diphosphate-induced platelet aggregation (platelet aggregation, in aggregation units × min) was assessed on a Multiplate analyzer. Patency was verified venographically at procedure end and was evaluated with duplex ultrasound in regular follow-ups.

RESULTS

Iliofemoral venous flow was successfully re-established by percutaneous endovascular angioplasty and stent implantation in nine left-sided and one bilateral iliofemoral post-thrombotic venous obstruction. Under dual treatment strategy of rivaroxaban and clopidogrel with platelet aggregation control (median (range): 285 aggregation units × min (192; 402)), none of the patients experienced restenosis or stent thrombosis, respectively. After a median follow-up of 14 months (range: 6-26 months), the primary patency rate was 100% and no in-stent restenosis, stent occlusion or relevant minor or major bleeding occurred.

CONCLUSION

Combined factor Xa inhibition and tailored antiplatelet therapy after stenting of iliofemoral post-thrombotic venous obstruction were safe and performed favorably in terms of vessel patency.

Short-Term Clinical Experience with a Dedicated Venous Nitinol Stent: Initial Results with the Sinus-Venous Stent

OBJECTIVE

Deep venous stenting has become the primary treatment option for chronic venous obstructive disease, both for iliac vein compression and post-thrombotic venous lesions. Until recently, only stents aimed at arterial pathology were used, because no dedicated venous stents were available. However, three such stents have now become available. These venous stents are characterized by increased length, diameter, flexibility, and radial force. This study reports an early experience with one of these devices; the sinus Venous stent (OptiMed GmbH, Ettlingen, Germany).

METHODS

Between March 2012 and July 2014, 75 patients were treated with the sinus Venous stent: 35 cases of iliac vein compression syndrome and 40 cases of unilateral chronic obstruction in post-thrombotic syndrome (PTS). Diagnosis of relevant obstruction was made using clinical evaluation, duplex ultrasound, and magnetic resonance venography. Patency during follow up was assessed with duplex ultrasound. Clinical improvement was assessed by VCSS, Villalta score, rate of ulcer healing, and improvement of venous claudication.

RESULTS

The cumulative patency rates at 3, 6, and 12 months were 99%, 96%, and 92%, respectively. The cumulative assisted primary patency rates were 99% at 3, 6, and 12 months. The cumulative secondary patency rate at 12 months was 100%. Differences exist in patency rate between the subgroups of non-thrombotic and post-thrombotic, with the first showing no re-occlusions. All re-thromboses in the PTS group were treated by ancillary treatment modalities. VCSS and Villalta score decreased significantly after stenting, as did venous claudication. Morbidity was low without clinically relevant pulmonary embolism, and mortality was nil. Although two out of seven ulcers healed temporarily, no ulcer remained healed at 12 months follow up.

CONCLUSION

Short-term clinical results using the sinus Venous stent are excellent, with significant symptom reduction, low morbidity rates, and no mortality. Loss of stent patency is seen less often compared with arterial stents described in the literature.