Experimental Study On Non-invasive Closure Of Saphenous Vein In New Zealand Rabbits By High Intensity Focused Ultrasound(HIFU)

Objective: To study the efficacy and safety of high intensity focused ultrasound(HIFU)in non-invasive closure of saphenous vein in New Zealand rabbits,and to compare the advantages and disadvantages and clinical application value of point therapy and regional therapy.Methods: 30 saphenous veins in the bilateral hindlimbs of 15 healthy New Zealand rabbits were divided into two groups: the left group and the right group.Intervention treatment was performed with HIFUNIT9000 focused ultrasound tumor ablation machine made by Shanghai Aishen Technology Co.,Ltd.The left side of the target vein was treated with point therapy and the right side was treated with regional therapy.The output power of 85 W,launch time of 150 ms and interval time of 300 ms were used in both groups.The vascular closure rate,blood flow recanalization rate and the incidence of complications in the two groups were statistically analyzed at 2 hours,7 days,14 days and 21 days after intervention.During the 21-day follow-up,no blood flow was defined as effective by target vein color ultrasound,and no blood flow was observed by color Doppler ultrasound at 2 hours after treatment,and blood flow was defined as recanalization at any time within 21 days of follow-up.At 21 days,5 diseased veins in each group were stained with hematoxylin-eosin staining(HE),and the efficacy,safety and clinical significance of the two treatments were compared.Results: A total of 30 saphenous veins were selected from 15 New Zealand rabbits,1 died during anesthesia and 28 effective experimental veins.The overall effective rate of non-invasive treatment with HIFU technique was 71.43%(20/28),of which the effective rate of point group was 64.29%(9/14)and that of regional treatment group was 78.57%(11/14).There was no significant difference between the two groups(P=0.678).After treatment,the effective rates of point therapy group and regional therapy group were 78.57% and 85.71%,respectively,and there was no significant difference between the two groups(P=1.000).On the 7th day after treatment,the effective rates of point therapy group and regional therapy group were 71.43% and 85.71%,respectively,and there was no significant difference between the two groups(P=0.648).At 14 days and 21 days after treatment,the effective rates of the two groups were the same,both 64.29% and78.57%,and there was no significant difference between the two groups(P=0.678).After 21 days of follow-up,the incidence of blood flow recanalization was 10.70%(3/ 28),including 14.29%(2/14)in the point treatment group and7.14%(1/14)in the regional treatment group,and there was no significant difference between the two groups(P=0.590).During the follow-up,the incidence of complications was 7.14%(2/28).There were no obvious complications in the point treatment group,and 2 cases in the regional treatment group had complications of 14.29%(2 /14),of which 1 case developed local skin burns immediately after treatment and was cured for 14 days without special treatment.1 case developed toe ischemic gangrene,bone exposure and arterial injury during14 days of follow-up.Conclusions: HIFU technique shows good effectiveness and safety in the study of non-invasive closure of saphenous vein in New Zealand rabbits.There is no significant difference in effective rate,vascular recanalization rate and incidence of complications between point therapy and regional therapy.this study provides a theoretical basis for the non-invasive treatment of venous diseases with HIFU,but its potential application value still needs to be further studied.