Cha Wittens

Mechanochemical ablation: status and results

The evaluation of endovenous ablation in recent years has gravitated towards the search for a technique that is simpler, painless and eliminates tumescent anaesthesia. These newer techniques must still be as efficacious and safe as endothermal methods. Over the last 10 years, numerous minimally invasive methods have been utilized to treat great and small saphenous vein incompetence. Most of these techniques involve percutaneous access, local anaesthesia, some form of ablation and short operative times with relatively good safety and efficacy. The endothermal technologies require the use of tumescent anaesthesia prior to energy delivery and a generator to produce either laser or radiofrequency energy. Results have improved and complications have decreased as these techniques and technologies have evolved. In the modern era of endothermal ablation (after 2006), efficacy rates of long-term closure are reported at levels well above 90%. However, these methods currently still require tumescent anaesthesia which can be a source of patient procedural discomfort; further, this portion of the procedure is the steepest part of the physician learning curve. Recent reports have evaluated ultrasound-guided foam sclerotherapy of the great saphenous vein (GSV). While foam sclerotherapy does obviate the necessity for tumescent anaesthesia, efficacy rates are lower than endothermal ablation and reported complication rates are higher. Presently, it cannot be stated that foam sclerotherapy is as efficacious as endothermal ablation. Other methods such as cyanoacrylate glue or polidocanol endovenous microfoam also accomplish saphenous closure without using tumescence. Long-term results of these methods are not currently published and clinical trials are ongoing. However the concept of tumescent anaesthesia elimination is central to all of these as with mechanochemical ablation (MOCA). A new mechanochemical device, (ClariVein) was developed to minimize the negative aspects of both endothermal ablation and ultrasoundguided sclerotherapy (UGS) for the treatment of saphenous incompetence, while incorporating the benefits of each. The advantages of this hybrid system are standard percutaneous access, endovenous treatment, local anaesthesia only (no tumescent anaesthesia) and a shorter procedure time. Since this system does not use thermal energy, the potential for nerve damage is minimized. The negative aspects eliminated by the hybrid procedure are: the need for tumescence anaesthesia required for endothermal ablation and lower efficacy rates for UGS. The mechanochemical method achieves venous occlusion utilizing a wire rotating within the lumen of the vein at 3500 rpm which abrades (i.e. injures) the intima and causes venospasm to allow for better efficacy of the sclerosant. A liquid sclerosant (sodium tetradecyl sulphate [STS] or polidoconol [PLD] is concomitantly infused through an opening close to the distal end of the catheter near the rotating wire. These two modalities, mechanical and chemical, achieve venous occlusion results equal to endothermal methods (Figures 1 and 2). The entire device is for single use only and can be inserted through a 4 or 5 Fr sheath utilizing local insertion site anaesthesia only, without the need of tumescence anaesthesia. The system includes an infusion catheter, motor drive, stopcock and syringe (Figure 3). Correspondence: S Elias MD FACS FACPh, Columbia Vein Programs, Division of Cardiac, Thoracic and Vascular Surgery, Columbia University and Medical Center, NY, USA, 350 Engle St, Englewood, NJ 07631, USA. Email: veininnovations@aol.com

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.

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.

Short-term follow-up of Quality-of-Life in interventionally treated patients with post-thrombotic syndrome after deep venous occlusion

Introduction Treatment of deep venous occlusive disease is gaining popularity, although the results and outcomes of various techniques are yet to be fully studied. Quality-of-Life (QoL) improvement is a valid and important outcome in medicine, but no specific QoL instruments for deep venous pathology exist up until now. We assessed the short term QoL effects of treated patients with post thrombotic syndrome after deep venous occlusion. Materials and methods Patients with proven venous occlusive disease referred to the outpatient clinic of our department of Venous Surgery in the Maastricht University Medical Centre were included. After inclusion, patients were treated by PTA and stenting and when indicated an endophlebectomy was performed and an AV fistula was made. QoL was assessed with the disease specific VEINES-QOL/Sym and the generic SF-36 questionnaires preoperatively at baseline and postoperatively at 3 and 12 months. Results 61 patients completed the 3 month follow-up period and 28 patients the 12 month follow-up period. VEINES-QOL and Sym scores improved after 3 months: 17.5 points for QOL (p = < 0.001) and 21.4 points for Sym (p = < 0.001)) and after 12 months 18.8 points for QOL (p = 0.004) and 21.3 points for Sym (p = 0.003)). The SF-36 scores improved significantly in the domains “physical functioning”, “role physical” and “bodily pain”. Conclusions Treating deep venous occlusive disease leads to short-term improvement of both disease specific QoL as well as generic QoL scores. Larger long-term follow-up studies are needed to corroborate these results.

Quality-of-life in interventionally treated patients with post-thrombotic syndrome

Introduction New developments in the treatment of complex deep venous disease have become available in the last decade. Besides analysing patencies as a surrogate outcome for these treatments we analysed the Quality-of-Life (QoL) changes for successful and failed deep venous treatments. Materials and methods Patients with proven venous occlusive disease, referred to our department of Venous Surgery at the Maastricht University Medical Centre, were included. After inclusion patients were treated by percutaneous transluminal angioplasty and stenting and when indicated endophlebectomy with an arteriovenous fistula. QoL was assessed with the disease specific VEINES-QOL/Sym and the generic Short-Form (SF)-36 questionnaires preoperatively at baseline and post-operatively after 3, 12 and 24 months. Results One hundred fifty-three interventions were analysed, showing a primary, assisted primary and secondary patency of respectively 65%, 78% and 89% at 24 months. The VEINES-QOL and Sym scores improved at 3, 12 and 24 months. The overall improvement at 24 months is 22.7 for QoL and 18.18 for Sym with respective p values of 0.013 and 0.016. The improvement of the VEINES-QOL and Sym scores after a successful (patent) treatment remained highly significant (QoL: p < 0.001, Sym: p = 0.004). Also the generic QoL (Short-Form 36v2) shows significant improvement after 12 months for physical functioning (p = 0.004) and role physical (p = 0.004) scales. Conclusions The overall patencies of interventions for deep venous pathology are exceptionally good after two years. Concomitantly the VEINES-Sym and VEINES-QOL scores improve significantly for 3, 12, and 24 months when compared to the baseline (T0) after treatment. Successful interventions showed, as expected, a significant greater QoL improvement between T0 and T3, T12, T24 for both VEINES-QOL and VEINES-Sym scores when compared to the failed interventions. The one-year linear improvement of two SF-36 scales (PF and RP) is also significant.

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.

Diagnostic imaging of pelvic congestive syndrome

Many female patients are affected by chronic pelvic pain and a significant number of referrals to the gynecology department result in a clinical suspicion of pelvic congestion syndrome. Additionally, patients referred to the vascular surgery department for venous disease can also present with complaints of a persistent dull lower abdominal pain in addition to typically distributed leg varicosities (that extend from the leg through the pelvic floor) which should be evaluated for the presence of pelvic congestion syndrome. In this article, we focus on imaging pelvic vein insufficiency and related (extending) varicosities: how should we evaluate the pelvic veins, what are the signs to look for, and what are the currently established criteria for (pre-interventional) imaging.

Prevention of venous thromboembolism in patients undergoing surgical treatment of varicose veins

Introduction: There is no consensus among surgeons with regard to prevention of venous thromboembolism (VTE) in patients undergoing surgical treatment of varicose veins. We performed a systematic review of the available literature. Methods: We systematically searched the online database from PubMed for studies about the incidence of VTE and thromboprophylaxis in varicose vein surgery. We included 13 papers for review. Results: The incidence of VTE after varicose vein surgery remains unclear. Most retrospective case series report an incidence of deep venous thrombosis (DVT) of approximately 1%, based on a clinical diagnosis. However, three prospective studies have systematically detected DVT by means of duplex ultrasound and showed that the true incidence might be 5–10 times higher than expected on a clinical basis. Discussion: More data on the incidence of VTE, and the need for postoperative thromboprophylaxis are necessary to formulate evidence-based clinical guidelines. Therefore, high-quality randomised clinical trials, with high numbers of included patients, and ideally comparing prophylaxis to placebo are warranted.

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.