Editor's Choice - Quality of Life after Stenting for Iliofemoral Venous Obstruction: A Randomised Controlled Trial with One Year Follow Up

OBJECTIVE

Deep venous obstruction (DVO) is a great burden on the healthcare system and patients' quality of life (QoL). Case series show stenting is safe and effective, however most studies lack control groups and QoL changes have not been compared with conventional treatment. The aim was to assess the difference in QoL changes from baseline to 12 months between stent and conventionally treated patients with DVO.

METHODS

Subjects > 18 years old with DVO due to post-thrombotic (PTS) or non-thrombotic iliac vein lesions (NIVLs) in a tertiary hospital were prospectively randomised to best medical therapy (BMT) or stent placement with BMT in a ratio 2:1, stratified for PTS or NIVL. The primary outcome was the between group difference in VEINES-QoL scores change from baseline to 12 months after treatment. Secondary outcomes included the difference in score changes for EuroQoL 5-Dimension 5 Level (EQ-5D-5L), Pain Disability Index (PDI), Venous Clinical Severity Score (VCSS), and the Villalta score.

RESULTS

After three years, the inclusion rate dropped to almost zero, therefore the study had to be stopped. Sixty-three patients were randomised to either the stent (n = 42) or control group (n = 21). Overall, 50 patients had available data for primary outcome analysis. The adjusted mean difference between 12 month scores for VEINES-QoL and VEINES-Sym was 8.07 (95% CI 3.04 - 13.09) and 5.99 (95% CI 0.75 - 11.24) (p = .026), respectively, in favour of the stent group. The differences were significant, but a pre-defined meaningful 14 point improvement in QoL was not reached. The mean difference between 12 month scores for VCSS was -2.93 (95% CI -5.71 - 0.16, p = .040), -11.83 (95% CI -20.81 - 2.86, p = .011) for PDI, 0.015 (95% CI -0.12 - 0.15, p = .82) for the EQ-5D index, and -2.99 (95% CI -7.28 - 1.30, p = .17) for the Villalta score.

CONCLUSION

Symptomatic patients with DVO who received dedicated venous stents had significantly higher VEINES-QoL/Sym scores at 12 months compared with the control group, but the between group difference was lower than the pre-specified clinically relevant QoL difference of at least 14 points.

STUDY REGISTRATION NUMBER

NCT03026049.

Single-center experience with catheter-directed thrombolysis and balloon angioplasty for acute upper-extremity deep vein thrombosis: a case series study

BACKGROUND

Effective treatment of upper extremity deep vein thrombosis (UEDVT) is crucial to prevent further complications. Various treatments, including percutaneous mechanical thrombectomy (PMT), catheter-directed thrombolysis (CDT), decompression surgery, and venoplasty are suggested for UEDVT. However, no prospective study has yet favored any of these treatments. This study presents a review of our experience with CDT followed by balloon venoplasty in patients with acute primary UEDVT.

METHODS

We enrolled all patients diagnosed with acute UEDVT from January 2020 to June 2021. Subjects with UEDVT due to secondary causes like malignancies, indwelling catheters, or leads were excluded. CDT was performed through brachial vein access, using a perfusion catheter, and rt-PA administration. Balloon venoplasty was performed if the treated segment had remaining stenosis after CDT. Patients were followed up at the vein clinic for any signs and symptoms in the upper extremity and lifestyle changes. Follow-up ultrasonography was done 12 months after discharge.

RESULTS

Twelve patients with a mean age of 41.08 ± 14.0 years were included in the study. The mean duration of CDT was 25.00 ± 10.56 h. After CDT, all patients had remaining occlusions, with seven having more than 50% remaining stenosis. However, after balloon venoplasty, no patient had significant (more than 50%) stenosis. There was no serious complication after both procedures. Patients were followed up for a mean duration of twelve months after their admission, with a mean time of maintenance anticoagulation was 10.73 ± 5.77 months. Only one patient had recurrent symptoms in his target limb which required a decompression surgery, while the rest were free of symptoms in their treated extremity. No subject developed pulmonary emboli (PE) during admission or the follow-up period. There was no evidence of hospital readmission for any reason. Upper extremity color-doppler sonography of the patients at twelve months after their procedure showed normal venous flow without any significant stenosis in 8 (66.7%), and partially normal flow with patent target vein in 4 (33.3%) patients.

CONCLUSIONS

CDT followed by balloon venoplasty may be an effective treatment for selected patients with acute primary UEDVT, providing desirable long-term results and potentially avoiding the need for decompression surgery in the short or long term.

Evaluation of safety and performance of a new prototype self-expandable nitinol venous stent in an ovine model

Objective

Our study was a prospective in vivo study performed on an animal model to evaluate the safety and performance of a novel venous stent designed specifically for venous applications.

Methods

The novel stents were implanted in the inferior vena cava of nine sheep. The stents were deployed with different distances between the closed cell rings to test for if the segments might migrate after being deployed at maximal distance. Three different total lengths were 9, 11, and 13 cm. After 1, 3, and 6 months, vascular injury, thrombus, neointima coverage, and stent migration were evaluated through computed tomography venography and histopathology. Imaging, histology, and integration data were analyzed for each group.

Results

All stents were deployed successfully, and all sheep survived until the time of harvesting. In all cases, the native blood vessel sections were intact. The segmented stent parts showed a differently pronounced tissue coverage, depending on the duration of the implantation.

Conclusions

The new nitinol stent is safe and feasible to implant in the venous system with a rapid surface coverage. Alteration of stent length did not affect the development of neointimal formation and did not cause migration.

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.

A risk score for iliofemoral patients with deep vein thrombosis

OBJECTIVE

Deep vein thrombosis (DVT) is a common condition with a high risk of post-thrombotic morbidity, especially in patients with a proximal thrombus. Successful iliofemoral clot removal has been shown to decrease the severity of post-thrombotic syndrome. It is assumed that earlier thrombus lysis is associated with a better outcome. Generally, the earlier IFDVT is confirmed, the earlier thrombus lysis could be performed. d-Dimer levels and Wells score are currently used to assess the preduplex probability for DVT; however, some studies indicate that the d-dimer value varies depending on the thrombus extent and localization. Using d-dimer and other risk factors might facilitate development of a model selecting those with an increased risk of IFDVT that might benefit from early referral for additional analysis and adjunctive iliofemoral thrombectomy.

METHODS

All consecutive adult patients from a retrospective cohort of STAR diagnostic center (primary care) in Rotterdam suspected of having DVT between September 2004 and August 2016 were assessed for this retrospective study. The diagnostic workup for DVT including Wells score and d-dimer were performed as well as complete duplex ultrasound examination. Patients with objective evidence of DVT were categorized according to thrombus localization using the Lower Extremity Thrombolysis classification. Logistic regression analysis was done for a model predicting IFDVT. The cut-off value of the model was determined using a receiver operating characteristic curve.

RESULTS

A total of 3381 patients were eligible for study recruitment, of whom 489 (14.5%) had confirmed DVT. We developed a multivariate model (sensitivity of 77% and specificity of 82%; area under the curve, 0.90; 0.86-0.93) based on d-dimer, Wells score, age, and anticoagulation use, which is able to distinguish IFDVT patients from all patients suspected of DVT.

CONCLUSIONS

This multivariate model adequately distinguishes IFDVT among all suspected DVT patients. Practically, this model could give each patient a preduplex risk score, which could be used to prioritize suspected IFDVT patients for an immediate imaging test to confirm or exclude IFDVT. Further validation studies are needed to confirm potential of this prediction model for IFDVT.

Iliocaval Skip Stent Reconstruction Technique for Chronic Bilateral Iliocaval Venous Occlusion

PURPOSE

To report safety and efficacy of a skip stent technique using nitinol stents in patients with chronic bilateral iliocaval venous occlusions.

MATERIALS AND METHODS

A retrospective analysis of 48 consecutive patients (32 men; mean age, 40.7 years; age range, 18-68 years) with chronic bilateral iliocaval obstructions treated using a nonoverlapping stent technique was conducted at a single center. None of the patients had May-Thurner syndrome. Iliocaval confluence was treated by deploying a nitinol stent in inferior vena cava (IVC) and a nitinol stent in each common iliac vein close to the caval stent. Patency of stents was assessed by duplex US at 2 weeks, 3 months, and 6 months and yearly thereafter.

RESULTS

Recanalization and stent reconstruction was technically successful in 47 (98%) patients. The sinus-XL venous stent was used to treat IVC (95 [100%]). Common iliac and external iliac veins were treated with sinus-Venous and VENOVO stents (80 [83%] and 16 [17%] limbs, respectively). External iliac and common femoral veins were treated with sinus-Venous and VENOVO stents (83 [92%] and 7 [18%] limbs, respectively). Early thrombosis (< 30 days) of the iliac vein with stent occurred in 2 limbs. Cumulative primary, assisted primary, and secondary patency rates at 30 months were 74%, 83%, and 97%.

CONCLUSIONS

Findings of this study suggest that leaving a skipped lesion at the level of iliocaval confluence may not adversely affect stent patency. Patency rates were comparable with other reported techniques of stent reconstruction at the level of iliocaval confluence.

Outcome of stenting in central venous obstruction of benign etiology

Background: The aim of this study is to evaluate long term outcome in patients treated for benign superior vena cava (SVC) syndrome by endovascular techniques. Patients and methods: Between 2015 and 2018, 62 patients suffering from central venous obstruction of benign etiology underwent balloon angioplasty with stent placement for venous obstruction in our department. Patency was assessed clinically, using duplex ultrasound in all patients or with CT-phlebography in selected cases. Results: Median age was 60 years (23-83), forty-one patients (66%) had central venous devices. Swelling of the arm and face were the main symptoms (71%). During the median follow up of 22 months (9-38), cumulative primary patency was 71% after venous stenting. The cumulative assisted primary and the secondary patency were 85% and 92%, respectively. Conclusions: Recanalization and stenting of central vein obstruction has turned out to be the technique of reference and provides satisfactory mid-term patency rates. After adjusting for the risk factors, presence of AV-fistula remained a significant risk factor for recurrent stenosis or loss of patency after intervention.

Update on diagnosis and treatment strategies in patients with post-thrombotic syndrome due to chronic venous obstruction and role of endovenous recanalization

OBJECTIVE

After a first episode of lower extremity deep venous thrombosis, post-thrombotic syndrome (PTS) develops in 20% to 50% of patients despite adequate anticoagulation. Symptoms of PTS can vary from leg swelling to venous ulceration with disabling venous claudication. It significantly affects the patient's quality of life and has considerable socioeconomic consequences. This review gives an update on diagnosis and current treatment strategies in patients with PTS due to chronic venous obstruction, in particular regarding the role of endovenous procedures.

METHODS

This review article is based on a selective literature search in PubMed and the Cochrane Library. The terms "postthrombotic syndrome," "post-thrombotic syndrome," "chronic venous obstruction," "venous outflow obstruction," and "venous stent" were used as keywords. Selected publications addressed the diagnosis of and therapy for PTS. Acute deep venous thrombosis, thrombolysis, case reports, complications as a result of caval vein filters, animal experiments, PTS of the upper extremity, and PTS in children were excluded.

RESULTS

In addition to conservative treatment of PTS, the following invasive procedures are also available: open surgical reconstructions, hybrid procedures, and endovenous recanalization of the occluded iliocaval venous tract with stent angioplasty. Since introduction of dedicated venous stents in 2012, technical success, patency rates, and improvement in quality of life have been at least as good as results of open surgical reconstruction if not better.

CONCLUSIONS

First-line treatment should be conservative therapy. In case of therapy-resistant PTS with poor quality of life, the possibility of an invasive treatment should be evaluated. All invasive procedures are recommended with low levels of evidence. Therefore, deciding on an invasive treatment and type of procedure should be made individually. Because PTS is rarely a threat to life or limb, a minimally invasive treatment is preferred. Therefore, endovenous recanalization appears to be appropriate as the therapy of choice. In patients with involvement of the femoral confluence, endophlebectomy of the common femoral vein in addition to venous recanalization is inevitable to ensure an adequate inflow into the recanalized venous tract. It also secures a sufficient drainage of blood from the peripheral venous system. Because this hybrid procedure is burdened with a significantly higher risk of complications, strict criteria must be fulfilled to legitimize the indication for this procedure. For the best possible results to be achieved, the following perioperative and postoperative management must be considered: therapeutic anticoagulation, early mobilization, compression therapy, and systematic follow-up with duplex ultrasound.

Urine neutrophil gelatinase-associated lipocalin predicts outcome and renal failure in open and endovascular thoracic abdominal aortic aneurysm surgery

Urine neutrophil gelatinase–associated lipocalin (uNGAL) has been evaluated as a biomarker for AKI detection and adverse outcome in open and endovascular thoracoabdominal aortic aneurysm surgery. This observational, retrospective study included 52 patients. UNGAL was measured peri-operatively (48 h) and correlated with AKI requiring dialysis, tracheotomy and adverse outcome. Mean patients’ age was 64.5 years. A total of 26.9% (n = 14) developed AKI, and 21.1% (n = 11) required dialysis, tracheotomy rate was 19.2% (n = 10) and in-hospital mortality rate was 7.6% (n = 4). uNGAL levels were related to AKI requiring dialysis at ICU (p = 0.0002), need for tracheotomy at baseline and admission on ICU (p = 0.0222, p = 0.0028, respectively), as well as adverse discharge modality (p = 0.0051, p = 0.0048, respectively). Diagnostic quality was good for uNGAL levels at admission to ICU regarding AKI requiring dialysis (sensitivity: 81.8% [48.2–97.7]; specificity: 87.8% [73.8–95.9]; area under the curve (AUC): 0.874 [0.752–0.949]). The diagnostic quality of uNGAL was favorable for the prediction of tracheotomy (sensitivity: 70.0% [34.8–93.3]; specificity: 83.3% [68.6–93.0]; AUC: 0.807 [0.674–0.903]) and adverse discharge (sensitivity: 77.8% [40.0–97.2]; specificity: 83.7% [69.3–93.2]; AUC: 0.817 [0.685–0.910]). uNGAL may be valuable as an post-operative predictor of AKI and adverse outcome after open and endovascular TAAA repair.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sheep models for evaluation of novel patch and prosthesis material in vascular surgery: tips and tricks to avoid possible pitfalls

Background

In vascular surgery, novel synthetic prosthesis materials for patch-angioplasties, interpositions, bypasses and shunts are continuously under development and optimization. The characteristics of an ideal vascular prosthesis would display long-term patency, biocompatibility, durability, low porosity, lack of stich hole bleeding, ease of handling, kink resistance, infection resistance and reasonable costs. The aim of this study was to establish and report a reliable sheep model including potential pitfalls where those parameters could be analyzed. Before surgery, sheep were acclimatized for 4–8 weeks, during which parasite infections were treated and blood and serum parameters monitored. Twenty-four sheep underwent surgery, and carotid patch-angioplasties (n = 12), graft interpositions (n = 6) or arteriovenous prosthetic shunts (n = 6) were implanted. Half of the animals in each group were sacrificed after 2 weeks and the other half after 8 weeks. The implants were analyzed for patency, endothelialization, thrombogenicity and biocompatibility by clinical observation, blood flow measurement and pathological and histopathological (H&E, EvG) as well as immunohistochemical (Ki67, CD31) evaluations.

Results

Health monitoring of the sheep revealed a parasitic burden with endoparasites in all animals. Some animals showed thereby infestations in the bile duct causing fibrotic cholangitis with calcifications in the liver. In addition, sarcosporidia were detected in histopathological specimen of the heart in all animals. Parasitic burden correlated with blood counts and serum bilirubin levels. Both were significantly reduced by albendazole treatment within the acclimatization time. Patches, interposition grafts, and straight shunts were successfully implanted bilaterally in all animals. The total average operation time was 136 ± 21 min. Most animals (23/24) showed good patency rates and general condition after implantation. Pathological and histopathological/immunohistochemical analyses were suitable to determine thrombogenicity, endothelialization, cellular/fibroblastic proliferation, biocompatibility, inflammatory cell infiltration, and thickness of neointima in the prosthesis material.

Conclusions

We have developed a suitable experimental protocol with standardized and successful anesthesia- and surgical-procedures for patch-angioplasty, graft interposition, and arteriovenous prosthetic shunts. This sheep model allows testing of new prosthetic materials for biocompatibility, thrombogenicity, and endothelialization.

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.

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.

Effect of a new incision management system (PREVENA®) on wound healing after endophlebectomy of the common femoral vein: a case series

Background

New endovascular techniques facilitate treatment of complex deep vein obstructions in cases of post-thrombotic syndrome. In a relevant number of these patients, endophlebectomy including the implantation of an arteriovenous fistula between the common femoral artery and the femoral vein is indispensable in order to establish a good inflow. These procedures display a high risk of wound complications. Despite conservative efforts to prevent these postoperative complications, wound healing problems occur in more than 20 % of cases. The present case report is the first description of wound dressing using a PREVENA® incision management system in cases of endophlebectomy.

Case presentation

A single center’s experience with the incision management system PREVENA®, which was used after endophlebectomy and venous stenting in complex hybrid procedures in three white men aged 46 years, 53 years, and 61 years is the subject of this case report. Although the surgical procedures were performed under therapeutical anticoagulation and took a couple of hours, no wound complications occurred.

Conclusions

These encouraging results underline a potential benefit of the incision management system PREVENA® in cases of complex venous recanalization including endophlebectomy of the femoral vein as well as the implantation of an arteriovenous fistula.

Blunt Thoracic Aortic Injury in Case of a 15-Year-Old Boy: Difficulties and Possibilities of the Endovascular Approach

BACKGROUND

Blunt thoracic aortic injuries (BTAIs) are rare but life threatening. Most BTAI are caused by high-energy trauma. Among children with blunt trauma, the incidence of BTAI is below 1 percent. The present case deals with covered thoracic aortic rupture of a 15-year-old boy. Emphasizing the value and the difficulties of endovascular surgery in children is the motivation for this case report.

CASE REPORT

We are presenting the case of a 15-year-old boy, who suffered multiple traumata after accident. Beneath multiple fractures and a liver laceration, a thoracic aortic rupture with pseudoaneurysm of the aortic wall was diagnosed. Owing to the comorbidities, an endovascular therapy in combination with a transposition of the left subclavian artery to the common carotid artery was performed. The chronological line-up of the events and the endovascular treatment as well as the in-hospital follow-up are described.

DISCUSSION

Injury-induced BTAI in pubescent children rarely occurs. Only few cases can be found in literature, none of which were associated with the presented pattern of injury.

CONCLUSIONS

The optimal treatment for childhood BTAI is a case-by-case decision. We critically discuss the value of endovascular therapy in the present case.

Arteriovenous fistula geometry in hybrid recanalisation of post-thrombotic venous obstruction

Introduction

Post-thrombotic obstruction can be adequately treated by percutaneous transluminal angioplasty and stenting. When post-thrombotic trabeculations extend below the femoral confluence, proper inflow can be facilitated by endophlebectomy and creation of an arteriovenous fistula. The aim of this study was to investigate whether it is more favourable to place the arteriovenous fistula at the cranial or caudal end of the endophlebectomy to prevent stenosis or occlusion.

Methodology

We retrospectively analysed the clinical data of all patients who underwent a hybrid procedure in our two centres. Demographics, interventional details and post-operative imaging were collected.

Results

Data on 42 limbs with cranially and 23 limbs with caudally placed arteriovenous fistulas were collected. Post-thrombotic disease of the profunda femoral vein alone or in combination with the femoral vein was observed more often in the cranial group. The caudal group more often received a smaller sized and straight polytetrafluoroethylene fistula, while the cranial group comprised a significantly higher amount of stented segments. Logistic regression showed that only reduced femoral inflow (hazard ratio 2.934 (95%CI, 1.148–7.494)) was a significant predictor of stent stenosis and/or occlusion. Logistic regression for risk of occlusion showed a significant influence of stent-related complications (hazard ratio 4.691 (95%CI, 1.205–18.260)) and a tendency towards influence of arteriovenous fistula geometry in favour of the cranially placed fistula.

Conclusion

Placement of the arteriovenous fistula in the cranial part of the endophlebectomy during hybrid recanalisation may result in a more favourable outcome, yet this tendency was not statistically significant. Moreover, femoral inflow is pivotal in maintaining patency and should thus be adequately assessed pre-operatively.

What predicts outcome after recanalization of chronic venous obstruction: hemodynamic factors, stent geometry, patient selection, anticoagulation or other factors?

In this review we evaluated the effect of different suggested factors associate with the outcome after recanalization of chronic venous obstruction (CVO).

Hemodynamic factors:

Based upon literature no clear suggestions can be made to identify the risk of stent occlusion in association with the hemodynamic effects. However it is evident that ensuring optimal in- and outflow of the stented tract is key in maintaining the patency.

Patient selection:

Noninvasive imaging modalities are used to divide patients in three subgroups based on the place and extension of post-thrombotic changes. Moreover it should be noted that AV fistula in selected patients can reduce the risk of thrombosis or re-occlusion.

Geometry:

Excessive oversizing of the stent and stent compression from outside are considered to be associated with stent occlusion. Additionally, overlapping rigid stents, unnatural angel between stents and in-stent kinking are other geometrical factors related to worse outcome after venous recanalization.

Anticoagulation:

Adequate peri-and postoperative anticoagulation has a crutial role in stent patency. There is no data regarding the duration of anticoagulation therapy and recommendations vary between 6 weeks to 6 months.

Result:

impaired inflow or outflow, presence of a hypercoagulability, total number of treated segments and use of stents designed for implantation in arterial system are associated with decreased stent patency.