Application Of Indocyanine Green Lymphography Combined With Methylene Blue Staining For Accurate Position In Lymphaticovenular Anastomosis Of Lower Limbs

Objective: As a surgical method for the treatment of limb lymphedema,lymphaticovenular anastomosis(LVA)has been gradually accepted by domestic clinicians and patients.Its purpose is to establish a lymphatic bypass to return the lymph of the affected limb to the vein.To reduce the incidence of venous reflux at the anastomotic site,it’s required to anastomose the small lymphatic vessels at the subcutaneous end with their accompanying small veins under an extremely fine surgical microscope more than 10 times.Because thin-walled lymphatics with a diameter of less than 0.8mm are usually difficult to find and anastomose,surgery is still challenging for plastic surgeons and requires sophisticated microsurgical techniques.The near-infrared fluorescent tracer indocyanine green(ICG)is routinely used to locate the approximate range of lymphatic vessels to be anastomosed before surgery.However,due to the severe fibrosis of subcutaneous tissues in some patients with lymphedema,it’s sometimes difficult to separate the lymphatic vessels to be anastomosed from the surrounding fibrotic tissues.When the surgeon thinks that the lymphatic vessels to be anastomosed may be difficult to find or identify during the operation,further accurate marking and positioning are required during the operation.Methylene blue is a traditional lymphatic tracer,which has a high affinity with the lymphatic system,and is easily absorbed by organisms.It is excreted through the kidney,with high safety and small adverse reactions.The preoperative position of ICG can effectively find out the approximate range of the small lymphatic vessels to be anastomosed,while the accurate position of methylene blue staining can clearly mark the small lymphatic vessels to be anastomosed.Methods: From October 2020 to June 2022,49 patients treated with LVA of lower limbs in the burn plastic and cosmetic surgery department of Xi’an Central Hospital were included in the study,and they were divided into the control group and the research group according to the order of arrival.In the control group,22 patients were all female,aged from 46 to 69 years,with an average age of 57 ± 7.7 years,all of them were secondary lower limb lymphedema;In the research group,27 patients were female,aged from 48 to 70 years,with an average of 58 ± 6.7 years,all of them were secondary lower limb lymphedema.In the control group,ICG lymphography was used as the position method,while in the research group,ICG lymphography combined with methylene blue staining was used as the position method,and LVA was performed.Observe and count the number of lymphatic vessels anastomosed,the time of lymphatic vessel searching,and the time of lymphatic vessel anastomosing during the operation,take them as comparative indicators to analyze the advantages of ICG lymphography combined with methylene blue accurate position in the LVA of lower limbs.At the same time,the Lower Extremity Lymphedema Index(LELI)and the Lower Limb Lymphedema Function,Disability and Health Questionnaire for Lower Limb Lymphoedema(Lymph-ICF-LL)were used as indicators to analyze the curative effect of patients half a year after operation and further explore the postoperative effect of LVA of lower limbs.Results: Both groups of patients were in stable condition during hospitalization.There was no significant difference between the two groups in terms of general data(P>0.05).The number of anastomotic lymphatic vessels in the research group was higher than that in the control group,and the searching time of lymphatic vessels was lower than that in the control group(P<0.05);There was no significant difference in lymphatic anastomosis time between the two groups(P>0.05).The scores of LELI and Lymph-ICF-LL in patients half a year after LVA were lower than those before operation,the volume of the affected limb was reduced,and the quality of life was improved compared with those before LVA,the difference was statistically significant(P<0.05).Conclusion: LVA can reduce the circumference of the affected limb and improve the quality of life in patients with lower extremity lymphedema,and the prognosis is good.ICG lymphography combined with methylene blue staining has the advantages of real-time visualization and accurate position,which can increase the number of anastomotic lymphatic vessels,shorten the time of searching lymphatic vessels during operation,and has high clinical application value.