Evaluating pharmacological THRomboprophylaxis in Individuals undergoing superficial endoVEnous treatment across NHS and private clinics in the UK: a multi-centre, assessor-blind, randomised controlled trial-THRIVE trial.

INTRODUCTION: Endovenous therapy is the first choice management for symptomatic varicose veins in NICE guidelines, with 56-70 000 procedures performed annually in the UK. Venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE), is a known complication of endovenous therapy, occurring at a rate of up to 3.4%. Despite 73% of UK practitioners administering pharmacological thromboprophylaxis to reduce VTE, no high-quality evidence supporting this practice exists. Pharmacological thromboprophylaxis may have clinical and cost benefit in preventing VTE; however, further evidence is needed. This study aims to establish whether when endovenous therapy is undertaken: a single dose or course of pharmacological thromboprophylaxis alters the risk of VTE; pharmacological thromboprophylaxis is associated with an increased rate of bleeding events; pharmacological prophylaxis is cost effective. METHODS AND ANALYSIS: A multi-centre, assessor-blind, randomised controlled trial (RCT) will recruit 6660 participants from 40 NHS and private sites across the UK. Participants will be randomised to intervention (single dose or extended course of pharmacological thromboprophylaxis plus compression) or control (compression alone). Participants will undergo a lower limb venous duplex ultrasound scan at 21-28 days post-procedure to identify asymptomatic DVT. The duplex scan will be conducted locally by blinded assessors. Participants will be contacted remotely for follow-up at 7 days and 90 days post-procedure. The primary outcome is imaging-confirmed lower limb DVT with or without symptoms or PE with symptoms within 90 days of treatment. The main analysis will be according to the intention-to-treat principle and will compare the rates of VTE at 90 days, using a repeated measures analysis of variance, adjusting for any pre-specified strongly prognostic baseline covariates using a mixed effects logistic regression. ETHICS AND DISSEMINATION: Ethical approval was granted by Brent Research Ethics Committee (22/LO/0261). Results will be disseminated in a peer-reviewed journal and presented at national and international conferences. TRIAL REGISTRATION NUMBER: ISRCTN18501431.

Defining the Parameters for Endovenous Microwave Ablation to Achieve Equivalence With Endovenous Laser Ablation, Using the Porcine Liver Model.

AIMS: Endovenous microwave ablation (EMWA) is an endovenous thermoablation (EVTA) system to ablate incompetent truncal veins. Early results suggest that EMWA uses more power than endovenous laser ablation (EVLA) to get the same results. We aimed to define the parameters for EMWA, which give the same tissue ablation as EVLA, using the validated porcine liver model. METHODS: EVLA (1470 nm 600 micron radial fibre) treatments were performed at 6 W, 8 W and 10 W, at pullback speeds of 6, 7, 8 and 9 s/cm, giving Linear Endovenous Energy Densities (LEEDs) between 36 - 90 J/cm. Each combination of power and pullback was repeated 5 times. We then used EMWA in the same model. Powers of 35-75 W and pullback speeds of 4-9 s/cm were used (LEEDs 140-675 J/cm). Ablation tracts from both devices were analysed by 2 blinded observers, noting thermal spread and carbonisation. RESULTS: For each commonly used parameter for EVLA, we identified a range of parameters for EMWA that produced similar tissue ablation in the porcine liver model. To keep the pullback speeds within the usual range, powers of 35-75 W were needed with EMWA, with mean EMWA LEEDs 3.9 - 5.8 times higher than EVLA LEEDs. We found the quicker the pullback speed, the higher the multiple of EMWA LEED we needed to get the same effect. CONCLUSION: We have identified parameters for EMWA that gave equivalent tissue ablation in the porcine liver model to commonly used parameters used for EVLA. These need to be validated clinically, but as the model used has already been validated against clinical outcome in endovenous thermal ablation, there is little reason to suspect that these results would not be valid. As the power during EMWA is higher than EVLA, EVMA LEEDs are approximately 4-6 times higher than EVLA LEEDs to achieve the same thermal effect on the tissues.

899 serious adverse events including 13 deaths, 7 strokes, 211 thromboembolic events, and 482 immune reactions: The untold story of cyanoacrylate adhesive closure.

OBJECTIVE: The aim was to retrieve and analyse the serious adverse events of venous occlusion systems used in cyanoacrylate adhesive closure (CAC) submitted to regulatory agencies. METHODS: The Total Product Life Cycle (TPLC) database of the US Food and Drug Administration (FDA), the Database of Adverse Event Notifications (DAEN) of the Australian Therapeutic Goods Administration (TGA), and the Yellow Card database of the UK Medicines and Healthcare Products Regulatory Agency (MHRA) were reviewed. Three Freedom of Information (FOI) requests had to be submitted to the MHRA to obtain data. RESULTS: The TPLC contained 899 reports which included 13 cases of death, 7 strokes, 211 thromboembolic events, and 482 immune reactions. The DAEN recorded three reportable adverse events, and the MHRA recorded seven adverse incidents including one death. CONCLUSION: CAC is associated with serious adverse events including death. These events are under-reported in the medical literature and only sub-optimally reported to the regulatory agencies.

Syncope (fainting on standing from squatting) due to massive venous reflux into lower limb varicose veins - Case report.

A 42-year-old man presented with very large lower limb varicose veins bilaterally and an 8-month history of fainting when standing up from a squatting position. He had been investigated for syncope by a cardiologist with no abnormality found on electrocardiogram, echocardiogram, 24-h electrocardiogram or 48-h blood pressure monitoring. Venous duplex ultrasonography showed bilaterally great saphenous vein reflux, with each vein having a diameter of 23.5 and 24.0 mm at the groin, and a similar dilation along the whole vein to ankle. These veins were successfully ablated with endovenous laser ablation, immediately following which the syncope disappeared and has not returned. We calculate that before treatment, the patient had approximately 500 ml of blood refluxing passively with gravity from his deep venous system on standing into his incompetent great saphenous veins and associated varicosities, which would account for his postural syncope.

Participant Reported Improvement in Cellulite by Vari-Pad Apparel and Objective Measurements - A "First Use" Pilot Study.

Background: Cellulite affects 80-90% of post-pubertal females and, although cosmetic, has proven adverse psychological effects. A new compression garment with patented "vari-pad" technology has been developed, aiming to stimulate lymphatic return from the buttocks and thighs. The primary aim of this small pilot study was to assess participant satisfaction after using this garment in the short term and secondarily, to look for any objective improvements. Methods: Eighteen female participants (mean 47.5y, range 26-60) completed the study. There were 2 weeks of "stabilisation", 4 weeks of wearing the garment, and 2 weeks of further assessment. With the initial assessment, there were 9 visits for each participant. At each visit, weight, participant satisfaction (0-10), 3D images (Canfield, USA) and transcutaneous water content (LymphScanner, Delfin Technologies, Finland) and comfort (0-10) were recorded. Results: There was no significant weight change in any of the participants during the trial period. After 4 weeks of wearing the garment, there was a significant improvement in participant satisfaction of their cellulite (n = 15, p = 0.0036) with a mean improvement of 18.5%. 3D image analysis of dimple volume showed no significant change in buttock cellulite, a significant decrease in left thigh cellulite (n = 17, p = 0.0123), but not on the right (n = 14, p = 0.6890). There was a significant decrease of localised water (n = 36, p = 0.0041). Comfort was 86% (range 40-100%) and there were no adverse reactions to the garment. Conclusion: The vari-padded compression garment produced a significant improvement in participant satisfaction after just 4 weeks of treatment. Objective measurements failed to show a significant difference in cellulite on the buttocks but showed a significant improvement in the thighs by analysis of both dimple volumes and reduced transcutaneous water measurements. Further study is suggested to demonstrate if longer timeframes for use of the apparel will lead to further significant improvement in the appearance of cellulite. NCT Number: NCT05748678.

Linear endovenous energy density (LEED) should always be quoted with the power used in endovenous thermal ablation - results from an in-vitro porcine liver model study.

BACKGROUND: Linear Endovenous Energy Density (LEED) is the energy used per cm of vein in endovenous thermal ablation (EVTA) but does not include time. This study examines the effect of time during EVTA. METHOD: EVTA was performed in a previously validated porcine liver model. LEEDs of 40, 60, 80 and 100 J/cm, using different powers were repeated 5 times each. Thermal spread, tissue carbonisation and device-tissue sticking during treatment were recorded. RESULT: LEED positively correlated to thermal spread and carbonisation of the tissue. Power was correlated with carbonisation but not thermal spread. Pullback had no correlations with thermal spread or carbonisation. Catheter sticking found occurred in powers >= 15 W or LEED >= 80 J/cm. CONCLUSION: LEED is a good measure of EVTA but does not include time. Power, which does include time, correlates with carbonisation and with device-tissue sticking. The power used must be quoted with the LEED.

Non-thrombotic superficial venous phlebitis secondary to Covid-19 vaccine or subsequent Covid-19 infection.

A 43-year-old woman presented with localised areas of prominent, tender superficial veins in her right arm and both legs, and chest pain, following the second dose of AstraZeneca vaccine and possible contemporaneous Covid-19 infection. Electrocardiogram, troponin and d-dimer had all been normal. However, a venous duplex ultrasound scan showed a perivenous inflammation without thrombosis in the areas of her limbs with prominent tender veins, but not elsewhere. We suggest that patients may present with prominent and tender superficial veins secondary to non-thrombotic phlebitis following Covid-19 infection or the AstraZeneca vaccine, which appears to be self-limiting. In addition, this case raises the possibility that Covid-19 infection or the AstraZeneca vaccine may directly affect cells in the vein wall, resulting in phlebitis without any evidence of thrombosis or microthrombosis. This phenomenon appears to be transient and self-limiting.

Endovenous Laser Ablation (EVLA) for Treatment of Varicose Veins: A Comparison of EVLA with 1470 nm and 1940 nm Lasers.

INTRODUCTION: Endovenous laser ablation (EVLA) using 1470 nm, which targets water as its chromophore, has become the standard endovenous thermal treatment for incompetent truncal veins. Recently, there has been growing interest in the use of 1940 nm, due to the greater absorption by water. This increased absorption has led to claims that, with the longer wavelength, less power is needed to achieve the same biological effect during treatment, resulting in fewer adverse post-operative sequelae. METHODS: Review of the current literature comparing 1940 nm and 1470 nm EVLA, which includes both laboratory-based and clinical studies. Reports on the use of 1920 nm were combined with those on 1940 nm. RESULTS: Increased absorption of the longer wavelength by water results in more thermal damage closer to the EVLA device. Thus, there may be an advantage to using the longer wavelength in EVLA of thin-walled veins at low power. However, in saphenous veins, which have thicker walls, there is little evidence that this different energy distribution in the vein wall makes any clinical difference. Reduced pain is likely to be due to reduced power during treatment. This is likely to result in more long-term failures of ablation using 1940 nm. CONCLUSION: There is a difference in the distribution of thermal damage in the vein wall between EVLA at 1470 nm and 1940 nm. However, there is little evidence of any clinically significant difference when used in incompetent saphenous veins. Clinical studies looking for a difference need to report the size and wall thickness of the treated vein, the power used as well as the energy per centimetre (LEED), and long-term ablation rates in addition to early post-operative pain, induration, paraesthesia and ecchymosis. Also, power loss in different laser / fibre systems and technical differences, such as those that might allow blood to remain in the vein being treated, need to be considered.

No significant difference between 1940 and 1470 nm in endovenous laser ablation using an in vitro porcine liver model.

Current endovenous laser ablation (EVLA) practice favours 1470 nm, as water is a major chromophore for this wavelength. Water has a greater affinity for 1940 nm, leading to claims that lower powers or linear endovenous energy densities (LEEDs) are needed. We compared the thermal spread and carbonisation of EVLA using these two wavelengths, in the porcine liver model. Using the previously validated porcine liver model, we performed 5 treatments, at each power: 2 W, 4 W, 6 W, 8 W and 10 W using a standard pullback of 8 s/cm. This gave LEEDs for each wavelength of 16, 32, 48, 64 and 80 J/cm. Digital images were given random codes and analysed by two blinded observers. Thermal spread was measured using "SketchandCalc" online software and graded carbonisation from 0 (none) to 3 (black carbon tract). There was no significant difference in thermal spread between the two wavelengths at 6 W, 8 W and 10 W. At 2 W, the 1470-nm laser had a significantly increased thermal spread over the 1940 nm. Significantly more carbonisation was found with the 1940-nm laser compared to 1470 nm. In this model, there was no significant difference in thermal spread at powers of 6 W and more. At 2 W and potentially 4 W, 1470 nm showed spread than 1940 nm, due to increased absorption at the device/tissue interface. At powers and LEEDs used for saphenous ablation, we found no evidence to support reduced power or LEED when using 1940 nm. However, 1940 nm may be more advantageous than 1470 nm when ablating small thin-walled veins, near to the skin.

Testicular vein thrombosis mimicking epididymo-orchitis after suspected Covid-19 infection.

A 70-year-old man presented to our vein clinic with intermittent and recurrent left testicular and groin pain, clinically resembling epididymo-orchitis. He had never had any genitourinary problems until contracting a severe flu-like illness in January 2020, strongly suspected to have been Covid-19. He had failed to respond on four separate occasions to antibiotics prescribed by his GP and had only responded on these occasions to aspirin. Duplex ultrasonography at our clinic showed thrombosis of the left testicular vein with venous collateral formation. The testicle itself showed mild oedema, but a reduced arterial flow supporting the pain to be secondary to thrombosis. Covid-19 is known to be associated with venous thromboembolic disease, but usually in patients sick enough to be hospitalised and particularly in those requiring intensive care. This man appears to have had a left testicular vein thrombosis secondary to relatively mild Covid-19 infection, as he did not require hospitalisation.

Clinical dilemma of management: Cardiac arrest after microsclerotherapy for lower limb telangiectasia with liquid 0.3% aethoxysklerol or idiopathic cardiac arrest?

A 48-year-old woman attended to discuss a dilemma. She had suffered a cardiac arrest immediately following microsclerotherapy of leg telangiectasia with 0.3% aethoxysklerol. She had successful defibrillation and been transferred to hospital. In hospital, despite normal cardiac tests, she was diagnosed as having idiopathic cardiac arrest. The exposure to aethoxysklerol was discounted by her cardiologists as a cause of her arrest. Following the hospital protocol, she was strongly advised to have an implantable defibrillator. Cardiac arrest and myocardial infarction are documented after aethoxysklerol injection with proposed mechanisms being anaphylaxis, direct cardiotoxicity or endothelin-1 release. Before consenting to an implantable defibrillator, which may have its own complications in the long term, doctors and the patient need to be certain that this arrest was not due to a reaction to aethoxysklerol.

Retrograde endovenous laser ablation of the great saphenous vein using the superficial inferior epigastric vein as access vessel illustrated by a case report.

Endovenous thermal ablation is a first-line treatment for symptomatic varicose veins due to truncal vein reflux. Ablation of an incompetent great saphenous vein is usually performed from distally, with the vein access at the lowest point of reflux, or just below the knee. Occasionally there are patients in whom the great saphenous vein is difficult to access distally for reasons such as small vein diameter, scar tissue, vasospasm, difficult anatomy or multiple attempts with haematoma formation. In such cases, we access the great saphenous vein in a retrograde fashion by percutaneous cannulation of the superficial inferior epigastric vein, passing the catheter into the great saphenous vein just distal to the saphenofemoral junction and then down the vein to the required distal position. Ablation can then be performed, stopping the ablation in the great saphenous vein just distal to the junction of superficial inferior epigastric vein and great saphenous vein. We present a patient to illustrate our technique.

Comparison of laser power output from the fiber tip during endovenous laser ablation against displayed power and the "first treatment" effect.

OBJECTIVE: International guidelines recommend endovenous laser ablation as one of the first-line treatments for truncal venous reflux associated with varicose veins. Clinicians use linear endovenous energy density to measure the energy used during treatment. The aim of this study was to investigate the power output from the fiber tip and to see if this changed with use. METHODS: We placed 15 mL of water in a thermally insulated 25-mL beaker. Two thermocouples were placed equidistantly adjacent to the laser fiber tip. A 1470-nm laser was fired at 5W for 2 minutes and the temperature change was measured. Three fibers were used on different days to allow the laser to cool for 24 hours between fibers. Each fiber was tested three times in a row. We also tested the "first treatment" effect by comparing the power output when the fiber was fired immediately after the laser was switched on, compared with treatments when the laser had been switched on for 1 hour. To assess whether this was due to the console being "cold" on the first firing of the day, we repeated the experiment having switched on the laser console 1 hour before firing to "prewarm" the console. However, the diode was not fired during this hour. To measure fiber degradation, three runs of the experiment were performed successively before firing the laser continuously for 20 minutes, then three more runs were conducted, resulting in delivery of approximately 10,000 J. RESULTS: The actual power output seemed to be lower than the console suggested. The power output from the first fiber used in a succession of three with the same laser had a significantly lower power output than the following two runs (P = .0004 and P < .0001, respectively). When the laser was prewarmed for 1 hour without firing, no change in this output pattern was noted (P = .293). Fiber degradation was not found in any of the fibers that were tested within the maximum recommended for the fiber (10,000 J). CONCLUSIONS: The first use of a fiber in a treatment session has a significantly lower power output from the treatment tip than subsequent uses, even if the machine is prewarmed and the console displays the same power for each. The authors believe that this phenomenon is due to the diode being less efficient when first used after switching it on. Clinicians need to be aware that the true power output at the fiber tip may not be as indicated by the console display and may be variable during a treatment session.

Pattern of thermal damage and tissue carbonisation from endovenous radiofrequency ablation catheter - Using an in vitro porcine liver model.

BACKGROUND: Successful endovenous thermoablation relies on transmural vein wall ablation. We investigated the pattern of thermal spread and tissue carbonisation from RadioFrequency-induced ThermoTherapy (RFiTT) at different powers and pull back methods, using a porcine liver model. METHODS: We used a previously validated in-vitro porcine liver model. Different powers from 5-25 W were used to administer 150 J. We compared continuous and pulsed energy delivery. Length, lateral spread, and total area of thermal damage, together with any tissue carbonisation, was measured using digital analysis software. RESULTS: All experiments used 150 J total energy. Total thermal damage area was smaller with lower power and pulsed energy. Continuous energy caused more tissue carbonisation than pulsed except at 25 W. CONCLUSION: Reduced thermal damage with lower power or pulsed energy results from cooling due to increased time of treatment. Increasing the power increases tissue carbonisation. Optimal treatment is determined by the highest power used continuously that does not cause tissue carbonisation.