A Randomised Clinical Trial Comparing Standard Cannula Delivered Foam Sclerotherapy, Catheter Directed Foam Sclerotherapy and ClariVein® Mechanochemical Ablation in the Management of Superficial Venous Insufficiency.
A Randomised Clinical Trial Comparing Standard Cannula Delivered Foam Sclerotherapy, Catheter Directed Foam Sclerotherapy and ClariVein® Mechanochemical Ablation in the Management of Superficial Venous Insufficiency.
Leaking valves in the veins of the legs causes veins to become large and bloated. These swollen veins are called "varicose veins" and are a very common problem, affecting more than a third of all adults in the UK. Varicose veins reduce people's quality of life by causing problems such as pain, itching and restless legs. Varicose veins may also damage the skin over time causing problems such as bleeding, skin colour changes, eczema and even break-down in the skin which is called an ulcer. Newer, "key-hole" methods of treating leaky veins have been developed as an alternative to surgery and can be performed under local anaesthetic with the patient awake. Rather than cuts in the skin, these minimally invasive techniques are performed through tiny stab wounds; little larger than needle holes. The varicose vein is then destroyed from within, usually using heat to burn the inside of the vein. These procedures are popular; with a rapid recovery and a very high success rate. However these methods also require the vein to be surrounded by a large volume of dilute local anaesthetic which can to be slightly painful to administer. A technique called "Foam sclerotherapy" involves the injection of a drug which has been mixed into a foam. This goes into the vein and causes it to stick shut. This procedure is near painless to perform as very few, small local anaesthetic injections are required; however the chance for a successful treatment first time are lower and patients may need to return for repeat treatments to successfully treat the vein.
The aim of this study is to see whether the success rates for this technique can be improved. One method "catheter directed foam sclerotherapy" involves the delivery of the foam through a catheter (a long very thin tube), so that large lengths of vein can be treated through a single hole. The final method "ClariVein" again uses a catheter; but this time the catheter has a small wire on the end which spins around inside the vein; similar to an edge strimmer in the garden; except it irritates the vein: rather than cutting it. This irritation makes the vein more susceptible to the drug which can again be applied directly to the vein wall whilst it is still active. Early results show that this final method is very successful; however the equipment is more expensive than for the other two.
This study will randomly allocate willing participants with varicose veins to receive one of these three treatments to see whether the two newer treatments can improve the success rates and quality of life improvements seen with foam sclerotherapy, whilst also allowing near painless treatment, without significant complications, at an appropriate cost.
. Investigational Plan Study Design This is a single centre three armed parallel group study with equal randomisation. The trial will be conducted in the Academic Vascular Surgical Unit of Hull York Medical School based at Hull Royal Infirmary, a university teaching hospital.
Target population The target population for this study are individuals with symptoms of SVI with ultrasound evidence of axial vein reflux and who have agreed to receive treatment for their axial vein reflux.
Recruitment Each patient referred to the vascular service with symptomatic SVI is assessed. Patients who potentially meet the inclusion criteria will be made aware of this research study and provided with the appropriate information, including the patient information sheet (see appendix 1). Patients will be given an opportunity to think about the invitation to participate and discuss with family/friends or other healthcare professionals if desired. Patients expressing an interest in participation will be offered an appointment for a screening visit with a study investigator.
Randomisation and Blinding Randomisation Participants will be randomised to one of the three treatments. Randomisation will be conducted by a sealed envelope system. Once enrolled in the study, efforts will be made to assess and manage all participants as outlined in the allocated treatment protocol until the pre-determined end-point of the study or until participant withdrawal. Following randomisation the participant's GP will be informed of the intended treatment modality Blinding Due to the nature of the procedures involved it will not be possible to blind the participant or clinical team as to which group the participant is allocated. Bias will be limited by the use of objective measurements, standardised protocols, use of patient reported outcomes and standardised assessor outcomes.
Power Calculation In order to detect a clinically significant difference in technical success of 15% with a power of 80% and a significance of 5%; 73 participants per group will be required. Assuming a 10% drop out rate we therefore aim to recruit 80 participants per group. The study will therefore randomise 240 participants in total over the 3 study groups.
Treatment Protocol All cases will be performed on a day-case, out-patient basis as per the standard practice in our unit by an experienced endovenous surgeon. For each participant, the investigating team will re-assess the inclusion and exclusion criteria, confirm the consent and undertake the procedure as per the protocol.
Participants judged to be at high risk of venous thromboembolic disease (VTE) due to the use of exogenous oestrogens, past medical history or a family history of VTE or thrombophilia or immobility will be given a single pre-operative dose of prophylactic molecular weight heparin (LMWH), in the absence of contraindications. All participants will have duplex assessment and marking using the same protocol with only the endovenous procedure differing.
The sclerotherapy drug used will be Sodium Tetradecyl Sulphate, also known as STD and marketed as Fibrovein® (STD Pharmaceutical Products, Hereford, UK). STD comes in different variations of concentration, for this trial we will use 3%, 1.5% or 1% STD depending on the procedure protocol. STD can be used as foam or as a liquid preparation which makes it ideal for our study. The STD used will be from routine stocks. It will be stored at room temperature in a suitably secure location in the ward, clinic or theatre. Careful records will be kept regarding which participants receive STD and its batch number Preoperative procedure The treatment aim is to eradicate any significant SVI present in the limb. Preoperatively the veins are marked by the surgeon using duplex-ultrasound with the patient standing. This will identify the extent and position of the refluxing axial vein alongside any incompetent perforating veins and varicose tributaries. The significant superficial varicose vein (GSV, ASV, SSV, GV) to be treated will have its length measured and noted. In addition, the average diameter of the varicose vein will be calculated via three transverse images of the vein (proximal, middle and distal) and noted. Potential areas to be punctured by cannulae may have local analgesia applied prior to treatment. The participant will be positioned supine on the operating table where in the Clarivein and Ultrasound Catheter group sterile precautions including disinfectant skin preparation and sterile draping will be employed, and the Foam Sclerotherapy and tributary treatment group skin disinfectant only. The ultrasound transducer will be prepared with a sterile covering and secured to the sterile drapes to allow sterile intra-operative ultrasound duplex scanning.
Operative Procedure: Foam Sclerotherapy Group The axial vein will be cannulated under local anaesthesia with an 18G (green), 20G (Pink) or 22G (Blue) Intravenous cannulae under ultrasound guidance with the patient reclined in a supine position for GSV or ASV treatment, prone position if SSV or GV treatment. This will be performed at the lowest point of demonstrable reflux and throughout the length of the incompetent vein at 20cm intervals. Each insufficient tributary system will also be cannulated separately. Venous blood will be aspirated and the cannulae flushed with normal saline to confirm that each is inside the target vein. Local anaesthesia can be used at each puncture site prior to needle insertion if desired by the patient. Once the cannulae are secured the leg is elevated to empty the veins.
The foam is then prepared by the Tessari technique by the surgeon. Two 2-ml syringes will be connected via a three way stop-cock tap and a 5 micron filter in series (Braun Medical, Sheffield, UK). The syringes will contain 1 part Sodium Tetradecyl Sulphate 3% and 3 parts air. In practice 0.5ml of 3% STS will be drawn up against 2 ml of air. The foam will be produced by at least 20 passages from syringe to syringe through the filter.
Up to 2ml of foam will be injected into each cannula under ultrasound control to observe venous spasm, followed by gentle massaging of the skin to propagate the foam through the segment of vein treated. The surgeon will also endeavour to prevent propagation of fresh foam beyond perforators and junctions into the deep venous system. The patient will be asked to dorsi-flex and plantar-flex their ankle several times to clear any foam which might have entered the deep venous system. At least 30 seconds will be left between each injection of foam. As per the European consensus guidelines a maximum of 12mls of foam will be used at one sitting32 33. Typical volumes of foam reported by Bradbury are 4-12ml in the GSV and 2-8 ml in the SSV34. After ensuring that the axial vein is treated the surgeon can then progress to the treating the tributaries and application of the dressings, as detailed below.
Operative Procedure: Catheter Directed Foam Sclerotherapy (CDS) Group The straight segment of axial vein will be cannulated under local anaesthesia at the lowest point of demonstrable reflux and a guide-wire inserted to facilitate the placement of the catheter system. The access cannulae will be removed and replaced with a 5F introducer sheath over a guide. A Unifuse® (AngioDynamics, Cambridge, UK) catheter system will be deployed via the sheath.
Unifuse® catheters available are 5F with either 45 cm or 90 cm lengths in combination with 5cm, 10cm or 15cm long infusion patterns. The appropriate Unifuse® catheter will be selected and deployed through the introducer sheath and advanced to within 2cm of the junction or perforator at the upper limit of incompetence or the top of the incompetent segment in the case of segmental reflux. The catheter will be aspirated to ensure correct position and flushed with normal saline. Each tributary system will be cannulated as was the case in the FS group.
A 1:3 foam of 3% STD will be produced as described for FS. At this point the patient will be repositioned into a Trendelenburg position (head up). The Unifuse® Self-Occluding ball wire will be inserted and the tip correctly positioned at 2cm from the junction under ultrasound guidance. As the internal diameter of the Unifuse® catheter is 1mm (3F) approximately 0.35ml of foam in the 45cm catheter or 0.7ml of form for the 90cm catheter will be injected to fill the dead-space. The appropriate volume of foam will be then be infused through the Unifuse® catheter during withdrawal under ultra-sound guidance. The catheter will be withdrawn the length of the infusion pattern following each injection. The surgeon will endeavour to prevent propagation of fresh foam beyond the perforators and junctions into the deep venous system. The maximum volume of foam used in one sitting is again limited to 12 ml, although the dead space in the catheter will be added to this. Once the varicose vein is treated the total volume of foam used is noted. After ensuring that the axial varicose vein is treated the surgeon can then progress to the treating the tributaries and application of the dressings, as detailed below.
Study Visits Baseline measurements will be collected from all participants once consent is obtained and prior to randomisation. Study measurements will be taken on the day of treatment and at the 1, 6, 12 and 52 week follow-up appointments, as detailed below Visit 1 (Baseline Assessment)
This assessment takes place after the signing of the consent form but prior to randomisation. Information collected will include:
Identification and Demographic details
o GP practice name with contact details
Employment Status and Occupation
o National Statistics Socio-economic Classification (NS-SEC)
Medical History including
Clinical Examination including
Photographic record of baseline limb appearance/bruising surface planimetry
o Anterior, left lateral, posterior and right lateral aspects
Duplex findings
Quality of Life Measurements
Vein axis/axes treated
Number of tributary veins treated
Length of axial vein and average diameter of vein
Total duration of procedure
Total volume of sclerotherapy (in ml) used per concentration
Length and type of treatment catheter used (where applicable) Non-technical treatment measurements
Visual analogue pain score (VAS)
Daily analgesia diary for 1 week post procedure (with tablet numbers) Visit 3 (1 week post treatment) This visit should take place ±1 day from the target visit date.
Collection of the 1 week VAS
Collection of the 1 week Analgesia Diary
Objective scoring of clinical severity. This will be assessed using both the VCSS and CEAP scores.
Generic Quality of Life Assessments
Disease specific Quality of Life Assessments
The number, timing and nature of any further treatment required
Satisfaction visual analogue scale
Cosmesis visual analogue scale
Bruising visual analogue scale
Bruising surface planimetry
Time to return to normal activities
Number of primary care calls/visits related to this treatment
Any additional secondary care costs related to this treatment (e.g. drugs to treat complications / additional clinic visits / days spent in hospital)
Venous Duplex Ultrasound Visits 4, 5 and 6 (6, 12 and 52 weeks post treatment) These visits should take place ±7 day from the target visit date.
Abbreviated medical history and clinical assessment
Objective scoring of clinical severity. This will be assessed using both the VCSS and CEAP scores.
Generic Quality of Life Assessments
Disease specific Quality of Life Assessments
Pain visual analogue scale
Satisfaction visual analogue scale
Cosmesis visual analogue scale
Bruising visual analogue scale
Bruising surface planimetry
Time to return to normal activities
Number of primary care calls/visits related to this treatment
The number, timing and nature of any further treatment required
Any additional secondary care costs related to this treatment (e.g. drugs to treat complications / additional clinic visits / days spent in hospital)
Venous Duplex Ultrasound Additional Treatment Visits Participants who undergo additional treatments (as per treatment protocol) will require an additional "baseline" and set of measurements as detailed below. Visits will be identified with the prefix A, B, C… etc. to differentiate between treatment rounds if more than one session is required.
Visit A0 (Additional Treatment Baseline)
Objective scoring of clinical severity. This will be assessed using both the VCSS and CEAP scores.
Generic Quality of Life Assessments
Disease specific Quality of Life Assessments
Photographic record of baseline limb appearance
o Anterior, left lateral, posterior and right lateral aspects
Duplex findings
Vein axis/axes treated
Number of tributary veins treated
Length of axial vein and average diameter of vein
Total duration of procedure
Total volume of sclerotherapy (in ml) used per concentration
Length and type of treatment catheter used (where applicable) Non-technical treatment measurements
Visual analogue pain score (VAS)
Daily analgesia diary for 1 week post procedure Visit A3 (1 week post retreatment) This visit should take place ±1 day from the target visit date.
Collection of the 1 week VAS
Collection of the 1 week Analgesia Diary
Objective scoring of clinical severity. This will be assessed using both the VCSS and CEAP scores.
Generic Quality of Life Assessments
Disease specific Quality of Life Assessments
Visual analogue satisfaction scale
Visual analogue cosmesis scale
Visual analogue bruising scale
Bruising surface planimetry
Time to return to normal activities
Number of primary care calls/visits related to this treatment
Any additional secondary care costs related to this treatment (e.g. drugs to treat complications / additional clinic visits / days spent in hospital)
Venous Duplex Ultrasound After this visit the participant will be followed up at the next scheduled routine appointment.
The primary outcome of this trial is the technical success rate of treatment at 1 year. The ultrasound appearances of the axial vein will be categorised as:
Fully occluded
Partial recanalisation (≤15% by length)
Widespread recanalisation (>15% by length). Secondary Outcomes Procedural - technical
Vein axis/axes treated
Number of tributary veins treated
Length of axial vein and average diameter of vein
Total duration of procedure
Total volume of sclerotherapy (in ml) used per concentration
Length and type of treatment catheter used (where applicable) Post procedure
Subjective treatment pain
Analgesia requirements for 1 week per treatment
Time to return to normal activities.
Subjective bruising assessment
Subjective satisfaction
Subjective cosmetic change
Objective bruising assessment
Change in clinical severity
Change in generic Quality of Life
Change in disease specific Quality of Life
The number, timing and nature of any further treatment required
Total number of primary care calls/visits related to this treatment
Any additional secondary care costs related to this treatment
Duplex Ultrasound measurements (proximal, middle and distal vein diameter) Expected Value of results Our proposed project would be the first to compare these three tumescent-free endovenous-ablative techniques. This will provide patients with a greater choice in their treatment and will usher in the next logical stage in endovenous treatments
Inclusion Criteria:
• Aged 18 or over
Exclusion Criteria:
• Inability to give informed written consent