Study On The Relationship Between The Grade ? Perforators And The Survival Of Reticular Blood-supplying Flap

Objective: To investigate the relationship between the perforating vessels of grade IV perforators and the survival of reticular blood-supplying flap,and to compare the distribution of grade IV perforating vascular network in multi-site skin tissue of the whole h?man body.Methods: 1.SD rats were divided into normal group,abdominal bilateral reticular blood-supplying flap model,dorsal bilateral reticular blood-supplying flap model,abdominal median reticular blood-supplying flap model,dorsal bilateral reticular blood-supplying flap model(n < 30).The models of reticular blood-supplying flap on both sides of abdomen and back were established in SD rats.Two rectangular reticular blood-supplying flap models with the size of 2cm × 8cm were established on both sides of the midline of abdomen and back of abdominal and dorsal rats,respectively.On the 7th day after operation,a piece of 0.5cm × 1.5cm tissue was taken from the proximal end of the flap and the junction of necrosis(distal),and the sections were embedded in paraffin and stained with HE.In the normal skin group,one piece of 0.5cm × 1.5cm tissue was cut from the abdomen and back at the design position of the reticular blood supply flap on both sides,and the sections were embedded in paraffin and stained with HE.Taking the midline of abdomen and back as the axis of skin flap,a vascular blood supply flap model of abdomen and back with the size of 8cm × 2cm was designed.The survival rate of the flap was observed after operation,in order to verify whether the results were consistent with the model of reticular blood-supplying flap on both sides.The patients with skin defects caused by trauma and tumor resection in the department of burn plastic surgery in our hospital were treated with transfer of skin flap from head and face,inner and outer thighs and inner and outer sides of leg to repair skin defects caused by trauma and tumor resection.after obtaining the informed consent of the patients and the examination and approval of the ethics committee,When the skin flap was sutured after the transfer of the flap,theredundant skin tissue of cat ear deformity formed during the suture of the donor area was collected and pruned and embedded in paraffin,sliced and stained with HE staining and CD31 vascular immunohistochemical staining.2.Seven days after flap resection,the necrosis boundary of skin flap was clear and stable.When taking pictures with digital camera,steel ruler was placed next to the flap,and the percentage of survival area of skin flap was calculated by Image J image analysis software.3.The skin tissues of SD rats were stained with HE,and the skin tissues of human skin were stained with HE and CD31,and then observed under microscope.10 dense areas of blood vessels were counted under 100 x microscope.4.Two slices were randomly selected from each specimen,and all the vascular visual fields were photographed under 100 x microscope.the larger vascular diameters were measured,recorded and sorted by Image J image analysis software.the maxim?m 20 vascular diameter data were included in the statistical analysis study.Results:1.The survival rate of reticular vascular blood supply flap in the back of SD rats was 75%and 85%,and that of abdominal reticular vascular blood supply flap was 50% and 62%,respectively.2.The density of perforating vessels of IV grade in normal back skin was higher than that in normal abdominal skin tissue(10.36 ±0.39 branches / 100 fold visual field VS 7.13±0.2branches / 100 fold visual field,p < 0.005).However,there was no significant difference in the diameter of perforating vessels of IV grade(58.15 ±1.29 ? m VS 57.92±1.72 ? m,P > 0.05).Seven days after operation,the diameter of the proximal IV perforating vessels in the abdominal and back skin flap group was slightly larger than that in the normal abdominal and back skin group,respectively.There was no statistical significance(64.87 ±2.25 ? m VS 57.92 ±1.72 ? m,63.53 ±2.97 ? m VS 58.15 ±1.29 ? m,P > 0.05).On the 7th day after operation,the diameter of the distal IV perforating vessel in the ventral and dorsal flap group was significantly lower than that in the proximal end(27.46 ±1.76 ? m VS 64.87 ±2.25 ? m,26.49 ±1.51 ? m VS 64.87 ±2.25 ? m,P < 0.05).Diameter of distal IV perforating vessels in abdominal and dorsal flap group 7 days after operation.There was no significant difference between them(27.46 ±1.76 ±3.09 ? m VS26.49 ±1.51 ? m,P > 0.05).7 days after operation,there was no significant difference in the density of proximal IV perforating vessels between the abdominal and back skin flapgroup and the normal abdominal and back skin group(7.97 ±0.17 vessels / 100 x visual field,VS 7.13 ±0.2branches / 100 x visual field),respectively,and there was no significant difference between the ventral and dorsal skin flap group and the normal abdominal and back skin group.10.61 ±0.25 / 100 x visual field VS 10.36 ±0.39 x / 100 x visual field,P >0.05);7 after operation.In the ventral and dorsal flap group,the density of IV grade perforating vessels in the distal end was higher than that in the proximal end(16.95±0.39 branches / 100 x visual field,20.07 ±0.71 branches / 100 fold visual field,VS 10.61±0.25 branches / 100 fold visual field,P < 0.05respectively).7 days after operation,the distal IV perforating vessels in the back flap group.The density was higher than that of the distal end of the abdominal flap group.The difference was statistically significant(20.07±0.71 branches / 100 x visual field,VS 16.95 ±0.39 branches / 100 X visual field,P < 0.05 P <0.05 P < 0.05.The difference was statistically significant(20.07 ±0.71 branches / 100 x visual field).In the group of reticular blood supply skin flap on the abdomen and back,many new capillaries could be seen at the distal end,and the phenomenon of "budding" could be seen in some of them.3.Many hair follicles and sebaceous glands can be seen in the skin tissue of the head,more capillaries can be seen around the hair follicles,and the number of arterioles in the head is large.The thickness of thigh skin and subcutaneous tissue is thicker than that of small leg.The comparison of vascular density: head > lateral leg > medial leg,external thigh >medial thigh,the difference was statistically significant(P < 0.05).The diameter of blood vessels: the head,the medial leg,the lateral leg > the medial thigh,the lateral thigh,the difference was statistically significant(P < 0.05).Conclusion:The distribution of IV grade perforating vessels is different in different parts of the whole body.The density of IV grade perforating vessels is of great significance for the survival of skin flap.The ratio of length to width of the flap was related to the density of subdermal vascular network and / or the diameter of blood vessels.