Rlm Kurstjens

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.

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.

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.

Intravenous pressure changes in patients with postthrombotic deep venous obstruction: results using a treadmill stress test

Essentials Little is known about the hemodynamic consequences of deep venous obstructive disease. We investigated pressure changes in 22 patients with unilateral postthrombotic obstruction. Common femoral vein pressure significantly increased after walking, compared to control limbs. Common femoral vein hypertension could explain the debilitating effect of venous claudication.

Hemodynamic significance of collateral blood flow in chronic venous obstruction

Introduction Complaints related to the post-thrombotic syndrome do not always correlate well with the extent of post-thrombotic changes on diagnostic imaging. One explanation might be a difference in development of collateral blood flow. The aim of this study is to investigate the hemodynamic effect of collateralisation in deep venous obstruction. Methodology Resting intravenous pressure of the common femoral vein was measured bilaterally in the supine position of patients with unilateral iliofemoral post-thrombotic obstruction. In addition, pressure in control limbs was also measured in the common femoral vein after sudden balloon occlusion in the external iliac vein. Results Fourteen patients (median age 42 years, 12 female) were tested. In eleven limbs post-thrombotic disease extended below the femoral confluence. Median common femoral vein pressure was 17.0 mmHg in diseased limbs compared to 12.8 mmHg in controls (p = 0.001) and 23.5 mmHg in controls after sudden balloon occlusion (p = 0.009). Results remained significant after correcting for non-occlusive post-thrombotic disease. Conclusion This study shows that common femoral vein pressure is increased in post-thrombotic iliofemoral deep venous obstruction, though not as much as after sudden balloon occlusion. The latter difference could explain the importance of collateralisation in deep venous obstructive disease and the discrepancy between complaints and anatomical changes; notwithstanding, the presence of collaterals does not eliminate the need for treatment.

Hemodynamic changes in iliofemoral disease

Background Iliofemoral venous obstruction, caused by post-thrombotic disease, can be treated by percutaneous angioplasty and additional stenting with good results. However, no hemodynamic parameter determining the need for treatment has been defined. This article describes the preliminary results of a study investigating the pressure changes occurring in post-thrombotic deep venous obstruction. Methodology Four patients with post-thrombotic deep venous obstruction of the iliofemoral tract were identified. Intravenous pressure was pre-operatively measured in the common femoral vein and in a dorsal foot vein bilaterally. During these pressure measurements patients were asked to walk on a treadmill with a speed of 3.2 km/h and a zero per cent slope, with the slope increasing two per cent every two minutes. Results Four patients (two male, two female) with age varying from 23 to 40 were identified. In two patients, disease extended below the femoral confluence. Pressure in the dorsal foot vein was not notably different between the affected and the control side. Pressure in the common femoral vein was markedly higher in post-thrombotic limbs compared to the control limb, with ambulatory pressure increasing more in post-thrombotic limbs. Conclusions These preliminary results are highly illustrative for the hemodynamic effect of iliofemoral deep venous obstruction due to post-thrombotic disease, even though sample size is admittedly limited. Furthermore, these results suggest that pressure measurements of the common femoral vein, and not the dorsal foot vein, might be able to identify a significant outflow obstruction due to post-thrombotic disease, though further inclusion of patients is necessary.

The predictive value of haemodynamic parameters for outcome of deep venous reconstructions in patients with chronic deep vein obstruction - A systematic review.

Objective The aim of this study was to investigate the predictive value of haemodynamic parameters on success of stenting or bypass surgery in patients with non-thrombotic or post-thrombotic deep venous obstruction. Methods EMBASE, MEDLINE and trial registries were searched up to 5 February 2016. Studies needed to investigate stenting or bypass surgery in patients with post-thrombotic obstruction or stenting for non-thrombotic iliac vein compression. Haemodynamic data needed to be available with prognostic analysis for success of treatment. Two authors, independently, selected studies and extracted data with risk bias assessment using the Quality in Prognosis Studies tool. Results Two studies using stenting and two using bypass surgery were included. Three investigated plethysmography, though results varied and confounding was not properly taken into account. Dorsal foot vein pressure and venous refill times appeared to be of influence in one study, though confounding by deep vein incompetence was likely. Another investigated femoral-central pressure gradients without finding statistical significance, though sample size was small without details on statistical methodology. Reduced femoral inflow was found to be a predictor for stent stenosis or occlusion in one study, though patients also received additional surgery to improve stent inflow. Data on prediction of haemodynamic parameters for stenting of non-thrombotic iliac vein compression were not available. Conclusions Data on the predictive value of haemodynamic parameters for success of treatment in deep venous obstructive disease are scant and of poor quality. Plethysmography does not seem to be of value in predicting outcome of stenting or bypass surgery in post-thrombotic disease. The relevance of pressure-related parameters is unclear. Reduced flow into the common femoral vein seems to be predictive for in-stent stenosis or occlusion. Further research into the predictive effect of haemodynamic parameters is warranted and the possibility of developing new techniques that evaluate various haemodynamic aspects should be explored.

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.