Application Of Infrared Fluorescence Imaging Technique With Indocyanine(icg)in Thinning Of Perforator Flap Of Miniature Pig

ObjectiveTo establish the model of perforating flap of superior abdominal artery of miniature pig,and to measure the effective thickness of perforating vessel by using indocyanine green near infrared fluorescence imaging technique to measure the penetrating subcutaneous adipose tissue.Then to measure the protection range of perforating vessel during thinning perforator flap.According to the protection range,to thin perforating branch flap and to study the effect of this imaging technology on the necrosis rate of perforating branch flap after thinning and to explore the navigation effect of ICG(Indocyanine green)near infrared fluorescence imaging in perforating flap thinning,which provide data reference for the clinical application of perforating flap thinning navigation technology.MethodsSix healthy adult Bama miniature pigs were used to establish animal model.1.Establishment and grouping of perforating branch flap model: After the anesthesia was satisfactory,bilateral abdominal flaps with left and right symmetry and self-control were obtained by cutting the superior abdominal vessels of miniature pigs as the axis of the skin flap.According to the random principle,the left or right side was designed as the control group,that was,the perforator flap without thinning,while the contralateral flap was designed to be thinned under the guidance of ICG near infrared fluorescence imaging technique.2.After the perforator flap of the experimental group was cut off,indocyanine green was injected intravenously.Along the direction of dry trunk of superficial veins of the lateral ventral wall with good exposure and good fluorescent imaging effect,three sites were randomly selected as the observation object,the uniform thickness of the adipose tissue was layered on the reference object.At the same time,the average effective thickness of adipose tissue was observed and measured by display ICG fluorescence contrast meter.By observing and measuring the selected perforating vessel through the display side of the contrast medium,it measured the farthest distance that the perforating peduncle disappeared from the branch vessel in perforating flap prostheses to measure distance for the radius and to delineate by the protection of blood vessels through the measurement range.Then,under indocyanine green fluorescein angiography,the skin flap was thinned outside the protective range of perforating vessels in the experimental group.3.The area necrosis rate of the flaps in the experimental group and the control group was measured.From the first day to the seventh day,the necrotic area of the skin flap between the experimental group and the control group was measured with transparent coordinate paper,and the necrosis rate of the flap area was converted to that of the control group.Results1.Gross observation of flaps in experimental group and control group: 6 experimental pigs in the first day after operation to the first 3 days,the skin flap swelling and skin tension increased in each group,and,the irregular skin flap necrosis was most obvious on the third day after operation,most of which were near the edge of the flap.On the 4th day after operation,the swelling of the flap began to recede.After 7 days of operation,the color of the flaps approached to normal,and the skin flaps in each group were infected with wired knots.After removing the thread 2 weeks later,the sutures were basically healed,the area of necrosis of skin flap started to scab off and exfoliated,and new epithelial tissue was grown.All the flaps survived.2.At the display end of ICG angiography instrument,the average protective range of perforating vessels in 18 miniature pig perforating flaps was measured by computer analysis software,which as the radius of perforating vessel pedicle,was(2.96±0.16)cm3.The average thickness of effective vascular development through the adipose tissue of miniature pigs was measured to be 6.00.(5.75,6.00)mm4.T test of independent samples was used to compare the area necrosis rate of different groups of flaps at different time points.The results showed that there was no significant difference in the area necrosis rate of flaps between the experimental group and the control group at each time point.(P>0.05).The analysis of variance was used to study the difference of the necrosis rate of the flap area between the experimental group and the control group at different time points.The results showed that the necrosis rate of the flap area in the experimental group and the control group was lower than that in the first day after operation from the second day after operation to the later time point.There was significant difference in the necrosis rate of flap area between the two groups at different time points.(P < 0.05).ConclusionIndocyanine green near infrared fluorescence imaging technique can reflect the position of abdominnal perforator vessel of miniature pig and its branches in real time during operation,define the protection range of perforating vessel,and ensure the integrity of blood supply system of perforating flap after thinning.Reduce the risk of large area necrosis of the flap,in the perforator flap thinning operation of miniature pig played the role of intraoperative navigation.