Carsten W. K. P. Arnoldussen

Efficacy of Radiation Safety Glasses in Interventional Radiology

PurposeThis study was designed to evaluate the reduction of the eye lens dose when wearing protective eyewear in interventional radiology and to identify conditions that optimize the efficacy of radiation safety glasses.MethodsThe dose reduction provided by different models of radiation safety glasses was measured on an anthropomorphic phantom head. The influence of the orientation of the phantom head on the dose reduction was studied in detail. The dose reduction in interventional radiological practice was assessed by dose measurements on radiologists wearing either leaded or no glasses or using a ceiling suspended screen.ResultsThe different models of radiation safety glasses provided a dose reduction in the range of a factor of 7.9–10.0 for frontal exposure of the phantom. The dose reduction was strongly reduced when the head is turned to the side relative to the irradiated volume. The eye closest to the tube was better protected due to side shielding and eyewear curvature. In clinical practice, the mean dose reduction was a factor of 2.1. Using a ceiling suspended lead glass shield resulted in a mean dose reduction of a factor of 5.7.ConclusionsThe efficacy of radiation protection glasses depends on the orientation of the operator’s head relative to the irradiated volume. Glasses can offer good protection to the eye under clinically relevant conditions. However, the performance in clinical practice in our study was lower than expected. This is likely related to nonoptimized room geometry and training of the staff as well as measurement methodology.

Value of magnetic resonance venography and computed tomographic venography in lower extremity chronic venous disease

For the treatment of chronic venous disease (CVD) of the lower extremity, identification of the underlying venous pathologies is essential. Traditionally, the pathologies to detect with imaging have been centred on insufficiency and reflux of the superficial, perforator and deep veins of the leg. More recently, stenosis and obstruction of the deep veins of the pelvis and abdomen (i.e. inferior vena cava, common and external iliac veins) have been identified as significant underlying pathologies in CVD. Accurate detection of stenotic and/or occlusive venous disease expands the treatment options for patients with CVD. In most cases, imaging of venous disease is performed with duplex ultrasound. In this article we discuss the existing evidence and potential value of computed tomographic venography and magnetic resonance venography to contribute in accurately identifying chronic venous disease, in particular chronic venous obstruction.

Minimally invasive treatment of chronic iliofemoral venous occlusive disease.

BACKGROUND As one of the primary etiologies of the post-thrombotic syndrome, chronic venous occlusion is a huge burden on patient quality of life and medical costs. In this study, we evaluate the short-term and midterm results of endovenous recanalization by angioplasty and stenting in chronic iliofemoral deep venous occlusions. METHODS This is a retrospective observational study set in a tertiary medical referral center. Patients with venous claudication or C4-6 venous disease combined with duplex and magnetic resonance-confirmed iliofemoral or caval occlusion were included. Patients with recent deep vein thrombosis (<1 year) were excluded. The intervention was endovascular deep venous recanalization, followed by angioplasty and stenting. Safety and feasibility were clinically evaluated during the procedure and during follow-up. Reocclusions and other treatment failures were evaluated during a maximum follow-up of 31 months by ultrasound imaging and venography. RESULTS Seventy-five procedures were performed in 63 patients (average age, 44 years; range, 18-75 years), of whom 86% had a history of deep venous thrombosis. The mean time between the initial deep venous thrombosis and treatment with PTA and stenting was 12 years (maximum, 31 years). May-Thurner syndrome was present in 57%. Forty-two procedures were performed in the left, six in the right, and 11 in both lower extremities. The vena cava inferior was partially stented in 25 patients. An average of 2.6 stents (median, 2) were used per procedure. Primary patency was 74% after 1 year. Assisted primary and secondary patency rates were 81% and 96%, respectively, at 1 year. Secondary procedures included restenting, catheter-directed thrombolysis, endophlebectomy of the common femoral vein, and creation of an arteriovenous fistula. No clinically evident pulmonary emboli were noted. A bleeding complication occurred after six procedures and was deemed major in two. No patients died. Relief or significant improvement of symptoms of chronic venous occlusive disease was achieved in 81% of patients. CONCLUSIONS Endovenous recanalization by angioplasty and stenting of chronically occluded iliofemoral vein segments is a safe and effective treatment with good short-term results, even when treatment takes place decades after the initial deep venous thrombosis. Most reocclusions can be adequately treated by a secondary procedure.

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.

Indications for endophlebectomy and/or arteriovenous fistula after stenting

Endovenous recanalization with percutaneous transluminal angioplasty and stenting in post-thrombotic syndrome patients with iliocaval obstruction is a treatment modality quickly gaining popularity. Studies show good patency and clinical success rates. If the obstruction extends distally, below the inguinal ligament, stenting remains controversial. Without adequate inflow, the patency of stented iliocaval segments drops dramatically. This suggests that treatment of diseased common femoral, femoral and profunda femoral veins is required to ensure adequate inflow. Endophlebectomy, the removal of synechiae and septae from the common femoral vein, is a viable option in these cases. Another option, which can be done concurrently with the endophlebectomy, is the creation of an arteriovenous fistula. Selecting patients for these interventions however remains difficult, as precise preoperative prediction of inflow into the stented segments is difficult. In this paper we describe our experience in using duplex ultrasonography, magnetic resonance venography and conventional venography to assess the patency of the inflow trajectory. We believe this approach is essential in dealing with cases of complex post-thrombotic disease extending below the inguinal ligament. There is a great need to establish criteria to accurately assess pre- and postinterventional flow through treated vein segments.

Feasibility of identifying deep vein thrombosis characteristics with contrast enhanced MR-Venography

Purpose To assess the feasibility of identifying deep vein thrombosis characteristics with contrast enhanced magnetic resonance venography. Materials and Methods A total of 53 cases of deep vein thrombosis extending in and/or above the common femoral vein were evaluated by 4 independent observers (2 expert, 2 novice) using pre-determined characteristics to determine the thrombosis present to be acute, sub-acute or old. If present, chronic remnants of a previous deep vein thrombosis were reported. Additionally these image qualifications were compared to the reported duration of complaints. Results In all cases all observers were able to qualify the thrombosis. The interobserver agreement between the experts was excellent (kappa 0.97) and good between expert and novice (kappa 0.82). Thrombosis identified as acute had an average duration of complaints of 6,5 (2–13) days, sub‐acute 13 (8–18) days and old 22 (15–32) days. Conclusion Qualification of thrombosis as acute, sub-acute or old and identification of chronic remnants of DVT with CE-MRV using routinely identifiable characteristics is feasible and reproducible with good to excellent interobserver agreement.

Editor's Choice – Reconstruction of the femoro-ilio-caval outflow by percutaneous and hybrid interventions in symptomatic deep venous obstruction

OBJECTIVE/BACKGROUND Deep venous obstruction is relatively prevalent in patients with chronic venous disease. Endovascular treatments and hybrid interventions can be used to relieve venous outflow obstructions. This paper assesses mid-term clinical outcomes and patency rates in a large cohort after percutaneous and hybrid interventions. METHODS This was a prospectively analysed cohort study. Patients with symptomatic deep venous obstruction who presented at a tertiary referral hospital were divided into three groups: patients who underwent percutaneous stenting for non-thrombotic iliac vein compression syndrome (IVCS group); patients with post-thrombotic syndrome (PTS) treated by percutaneous stent placement (P-PTS group); and PTS patients with obstruction involving the veins below the saphenofemoral junction in which a hybrid procedure was performed, combining stenting with open surgical disobliteration (H-PTS group). Patency rates, complications, and clinical outcomes were analysed. RESULTS A total of 425 lower extremities in 369 patients were treated. At 60 months, primary patency, assisted primary patency, and secondary patency rates were 90%, 100%, and 100% for IVCS, and 64%, 81%, and 89% for the P-PTS group, respectively. The H-PTS group, showed patency rates of 37%, 62%, and 72%, respectively, at 36 months. Venous claudication subsided in 90%, 82%, and 83%, respectively. At the 24 month follow-up, mean Venous Clinical Severity Score decreased for all patients and improvement in Villalta score was seen in post-thrombotic patients. The number of complications was related to the extent of deep venous obstruction in which patients in the H-PTS group showed the highest complication rates (81%) and re-interventions (59%). CONCLUSION Percutaneous stent placement to treat non-thrombotic iliac vein lesions, and post-thrombotic ilio-femoral obstructions are safe, effective, and showed patency rates comparable with previous research. Patients with advanced disease needing a hybrid procedure showed a lower patency rate and more complications. However, when successful, the clinical outcome was favourable at mid-term follow-up and the procedure may be offered to selected patients.

Venous In-stent Thrombosis Treated by Ultrasound Accelerated Catheter Directed Thrombolysis

OBJECTIVE/BACKGROUND Stent placement in the venous system is an increasingly used treatment modality in chronic venous obstruction and as additional treatment after thrombolytic therapy in ilio-femoral deep vein thrombosis (DVT). Experience in treating in-stent thrombosis with ultrasound accelerated catheter directed thrombolysis (UACDT) is reported. METHODS A retrospective analysis of patients treated for venous stent occlusion, after percutaneous transluminal angioplasty (PTA) and stent placement for either chronic venous occlusive disease or persistent vein compression in patients with acute DVT was performed. Duration of occlusion and suspected clot age were assessed using patient complaints and typical findings on duplex ultrasonography (DUS). DUS and venography were used to assess patency and to determine the cause of re-occlusion. Acute treatment of occlusion was by UACDT. Additional procedures included PTA, stent placement, and creation of an arteriovenous (AV) fistula. RESULTS Eighteen patients (median age 43 years; 67% male), treated for occluded stent tracts with UACDT between January 2009 and July 2014, were identified. Indications for initial stenting were treatment of chronic venous obstructive disease (12 patients) and treatment of underlying obstruction after initial thrombolysis in acute DVT (six patients). Technical success was achieved in 11/18 (61%) patients. Primary patency in 8/11 patients was 73% at last follow up (median follow up 14 months [range 0-41 months]). Additional treatments after successful lysis were re-stenting (seven patients) and creation of an AV fistula (six patients). CONCLUSION Treatment with UACDT of recently occluded stent tracts is feasible and effective. Recanalization of the stent tract can be achieved in most cases. Additional interventions were frequently used after successful UACDT treatment. Suboptimal stent positioning caused the majority of the stent occlusions.

Reconstruction of the femoro-ilio-caval outflow by percutaneous and hybrid interventions in symptomatic deep venous obstruction

through the Swedvasc database. The mandatory national health care registries and medical records provided data on comorbidities, mortality, and major amputations. Results: A total of 16,889 patients with PAD (IC, n = 6272; CLI, n = 10,617) were studied. The incidence of amputations in IC patients was 0.4% (range 0.3%e0.5%) per year. Among CLI patients, the amputation rate during the first 6 months following revascularisation was 12.0% (95% CI 11.3e12.6). Thereafter, the incidence declined to approximately 2% per year. The cumulative combined incidence of death or amputation 3 years after revascularisation was 12.9% (95% CI 12.0e13.9) in IC patients and 48.8% (95% CI 47.7e49.8) in CLI patients. Among CLI patients, compared with IC patients, the prevalence of diabetes, ischaemic stroke, heart failure, and atrial fibrillation was approximately doubled and renal failure was nearly tripled, even after age standardisation. Conclusion: The risk of amputation is particularly high during the first 6 months following revascularisation for CLI. IC patients have a benign course in terms of limb loss. Mortality in both IC and CLI patients is substantial. Revascularised CLI patients have different comorbidities from IC patients.

Theme 4: Invasive management of (recurrent) VTE and PTS

a Jobst Vascular Institute, Toledo Hospital, Toledo, OH, USA b Department of Hematology, Oslo University Hospital, Oslo, Norway c Center for Thrombosis and Hemostasis (CTH), University Medical Center Mainz, Mainz, Germany d Department of Radiology, Maastricht University Medical Centre, Maastricht, The Netherlands e Department of Surgery, Section of Vascular Surgery, Conrad Jobst Vascular Research Laboratories, Ann Arbor, MI, USA f Department of Radiology and Interventional Radiology, VieCuri Medical Centre, Venlo, The Netherlands g Department of Venous Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands h Department of Vascular Surgery, University Hospital Aachen, Aachen, Germany