The Clinical Application And Animal Experimental Study Of The Delayed Skin Flap

Part one The comparison between the delayed and the non-delayed calf fascial perforator nurtured flap in repairing fore-and mid-foot woundWhen repairing the fore-and/or mid-food damage calf fascial perforator nurtured flap is usually used.Yet the grafted flap is often failed to survive due to the poor blood supply.That is not only because the distal vascular perforators are too slender to nurture the damaged area but also the pedicles are shorter than the appropriate length and are over-stretched.Partial flap necrosis is very common during the early grafting time and this results in continuous dressing changes or a second skin graft.Moreover,there even exists bone exposures on distal wounds in some cases,which forces surgeons to remove part of the bone to close the wound.Thus treating wounds on mid-and/or fore-foot is rather difficult especially for the elder persons whose vessels are often atherosclerosis.Objective: To compare the effect of the delayed calf fascial perforator nurtured flap with that non-delayed in repairing the fore-and/or mid-foot wound.Methods: From March 2005 to September 2016 a retrospective study was done on 41 cases with fore-and/or mid-foot injuries.Among them 19 cases were operated with delayed calf fascial perforator nurtured flaps(12 cases for perforator-based sural neurofasciocutaneous flaps and the rest 7 cases for the posterior tibialartery perforator nurtured flaps).While the other 22 cases were operated with non-delayed calf fascial perforator nurtured flaps(14 cases for perforator-based sural neurofasciocutaneous flaps and the rest 8 cases for the posterior tibialartery perforator nurtured flaps).Statistical analysis of the postoperative data was done after a half-year follow-up.Results: There is statistically difference between the two groups as regarding to the re-operation rate and long-term dressing rate.As to the long-term quality of the flaps there is no difference.Conclusion: In repairing the fore-and/or mid-food damage delayed calf fascial perforator nurtured flap is better than that non-delayed as far as post-operative treatment is concerned.This method can shorten the average length of stay and can reduce both the re-operation and long-term dressing rate.Part Two Delayed effect of the abdominal skin flap on repairing avulsion injury of whole handAvulsion injury of whole hand is a severe damage and the hand functions will be seriously impaired if without proper handling.Traditionally the damaged hand is embedded in abdomen before skin grafting and this will take a long time without ensured success of the skin grafting in the initial period.Thus the delayed abdominal skin flaps were adopted to deal with this kind of injury on 11 cases.Also the traditional operations were conducted on 14 cases.The average length of stay,hand function,post-operative shoulder and elbow motion were compared.Objective: To evaluate the effect of the delayed abdominal skin flap on repairing the avulsion injury of whole hand.Methods: From March 2005 to September 2016 a retrospective study was done on 25 cases with whole hand avulsion injury.Among them 11 cases were operated with delayed abdominal skin flaps to deal with their palmar damage meanwhile the dorsal damage was repaired with the abdominal skin flaps for each one.While the other 14 cases were operated with traditional methods.Statistical analysis of the average length of stay,hand function,post-operative shoulder and elbow motion were done after a half-to-one year follow-up.Results: As regard to the delayed and the abdominal skin flaps all of them were survived with normal blood supply including tension blisters in one case and infection together with kirschner wire exposure in another case.After a 6-12-month follow-up,flap resistance and hand function were satisfactory.Of the other 14 cases,2 of them were cured with once skin grafting,while another 8 cases were cured with twice skin grafting,besides 4 patients survived with thrice skin grafting.There were significant differences between the two methods in hospitalization time,hand function,12-week shoulder and elbow motion.Conclusion: It’s available for the delayed abdominal skin flap to repair avulsion injury of the whole hand.Part Three Time-effect research of delayed flap with New Zealand white rabbitsThe clinical study shows that the delayed flap is better than the traditional flap in the survival rate and the survived area.Yet until which time we should delay our operation to earn the best blood supply has not been determined.Some people propose that the optimal time to transfer the flap is one week after operation because vascular reestablishment and enlargement of the flap slows down after a week.Other scholars believe that vascular reestablishment and enlargement slows down 10 days after operation.So they come up with the optimal transfer time is on the 10 th day.Thus we used animal experiments to study this issue by selecting 50 New Zealand white rabbits which were divided into two groups.Objective: To study the optimal time for the delayed flap to be transfered by animal experiment,and to provide a reliable basis for clinical operation.Methods: Fifty New Zealand white rabbits were selected and divided into two experimental groups:experimental group 1(EG1)for 30 rabbits and experimental group 2(EG2)for 20 rabbits.In EG1 which was randomly divided into 3 sub-groups(sub-group 1,sub-group 2,and sub-group 3)the diameters of the blood vessels at different time points were observed.Except the immediate postoperative measurements for all sub-groups observing time points for sub-group 1 were the 5th,10 th,15th day,for sub-group 2 were the 4th,8th,12 th day,and for sub-group 3 were the 3rd,6th,9th day.In EG2 which was randomly divided into 2 sub-groups(sub-group 4 and sub-group 5)together with 3 sub-groups of EG1 morphological study was done through HE and immunohistochemical staining of CD31 to research the vessel proliferation and enlargement.Observing time point for sub-group 4 is immediately after operation and the time for sub-group 5,3,2,1 is at the day 5th,9th,12 th,15th respectively.Western blot quantitative analysis of CD31 which determining the number of new blood vessels was also done on the above five groups at the same time point as HE and immunohistochemical staining.All groups were subject to random,parallel,and controlled principles.The rabbits of EG1 were operated with abdominal random skin flaps in the aspect ratio of 1:2 and then the vessel widths for each rabbit at each time point were recorded by raising the fascia layer.After each observation,the wound was washed thoroughly,the sterile rubber was put in,the flap was sewed and the rabbits were feed with antibiotics(0.2/100 ml water amoxicillin).Statistical analysis of the data obtained at different time points in EG1 was done.Further 50 specimens of the sub-groups were dealed with HE,immunohistochemical staining,and western blot.All the morphological data obtained were statistically analyzed.Results: Based on the data,the enlargement and proliferation of the major blood vessels was the fastest on the 3rd to 6th day for delayed flaps.The vessels were continued to increase during the 4th to 8th day,the 5th to 10 th day,the 6th to 9th day,the 8th to 12 th day.While the trend gradually slowed down and was in a state of stagnation between the 10 th and 15 th day.Analysis of the CD31 protein found that for 50 specimens,the number of choke vessels increased significantly until the 5th day.The number of choke vessels still increased on the day 6th and 9th.There was no significant change in the number of choke vessels on the 12 th and 15 th day(all compared with the immediate postoperative data).Conclusion: The proliferation speed of the vessels in choke area gains the maximum on the 5th day.Then the speed slows down and the proliferation even stops on the 9th day.Moreover the major vessels that supply blood to the flap gain the maximum diameters on the 3rd to 6th day and cease enlarging on the 10 th day.So it’s the optimal time for transferring the delayed flap on the 10 th day,or the enlargement and proliferation of the vessels would almost remain stalled.Besides over the above deadline the blood supply of the peripheral tissue will also nutrued the delayed flap which results in attenuating of the vessel pedicles that blong to the flap.