ABSTRACT
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.
Subject(s)
Laser Therapy , Liver , Microwaves , Models, Animal , Sus scrofa , Animals , Laser Therapy/instrumentation , Liver/surgery , Microwaves/therapeutic use , Endovascular Procedures/instrumentation , Swine , Ablation TechniquesABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.