Clinical And Experimental Study On Effect Of Leechss And Hirudin On Vein Congestion Of Random Skin Flap

Background: Skin flap transplantation is a commonly used treatment in plasticand reconstructive surgery. One of the complications after the transplantationwas the skin flap necrosis due to venous congestion, and, though not common,but can affect the efficacy. It has always been the hotspot and difficulty in thefield of plastic and reconstructive surgery about how to improve themicrocirculation, promote healing and improve the success rate of skin flaptransplantation. Clinical practice has proved that live leeches therapy intreatment of skin flap venous congestion is having direct effect, simple andconvenient distinctive features, and it was an effective treatment of skin flapscongestion. It has application and dissemination value in plastic andreconstructive surgery, cosmetic surgery and related disciplines. But live leechesliving in warm, humid paddy fields with a longer period of hibernation, and thebiological characteristics determine the blood-sucking therapy applications andthat will be the objective constraints of geography, climate, etc. There is no clearconclusion on Medical Ethics, so it is currently not widely popular in clinicalapplications. In order to exploit the clinical application of medical leech,research still needs for the effective constituents and expect the local injection ofhirudin to replace blood-sucking therapy to resolve the problem of congestionafter random pattern skin flap transplantation, in order to increase the successrate of operation. The research can be divided to three parts:Part One THE CLINICAL PRACTICE OF LIVING MEDICALLEECHES IN TREATING THE COMPLICATIONS OF RANDOMPATTERN SKIN FLAPObjective: To summarize and to explore the efficacy on clinical application ofliving leeches blood-sucking therapy on treating the venous congestion ofrandom skin flap.Method:Put the live leech to suck up blood on the surface of progressivelyincreased venous congested skin flap. Treatment ends after the blood supplyimproved significantly.Result: January 1995 to December 2008, of 8 patients, except only one case hada small area of necrosis of the distal edge; the remaining seven cases achieved agood therapeutic effect.Conclusion: Live leeches blood-sucking therapy was a simple, direct andlow-cost measure in treatment of skin flaps venous congestion. Part Two EXPERIMENTAL STUDY ON TOPICAL APPLICATION OFNATURAL HIRUDIN IMPROVES THE MICROCIRCULATION OF PIGCONGESTION FLAP (PHYSICAL INDICATORS, SOD, MDA and MPO)Objective: To investigate the effects of several biochemical indicators on topicalapplication of natural hirudin on pig congestion flapMethod: As experimental object, Guangxi Bama miniature pigs were employedto establish as an animal model of random skin flap congestion. The flaps were divided randomly into three groups: group A (local injection of isotonic NaCl toeach flap as a control group), group B (local injection of natural hirudin, 20ATU/flap), and group C (local injection of natural hirudin, 40 ATU/flap). Thelevels of Myeloperoxidase (MPO), Malondialdehyde (MDA), and SuperoxideDismutase (SOD) were measured.Result: The levels of MDA, MPO and SOD in medication groups (group B andgroup C) were significantly different from the control group in the same period(P<0.05). The above indicators in group B and C were not significantlydifferent (P>0.05). After 12 days of observation, the flap's survival rate of groupB and group C were higher than group A (P < 0.05), but cannot be consideredthe flap survival rate of group B was higher than group C (P > 0.05).Conclusion:By inhibiting the reaction of oxygen free radicals, natural hirudinimproves the microcirculation of congestion flaps, enhance the survival lengthof flaps. Part Three THE IMPACT OF NATURAL AND RECOMBINANTHIRUDIN ON RAT RANDOM SKIN FLAP CONGESTION MODEL OFVEGF AND TXB2Objective: To investigate the effect of natural hirudin and recombinant hirudinwhich are applied locally to the venous congestion on random skin flap in ratsmodels, and whether their effects on the flap of vascular endothelial growthfactor(VEGF) and thromboxane B2( TXB2) are the same or not. Method:Thirty Wistar rats, including male and female,were employed toestablish animal model of venous congestion flap. The flaps were dividedrandomly into three groups: group A (local injection of natural hirudin, 5ATU/flap), groups B (local injection of recombinant hirudin, 5 ATU/flap),group C (local injection of isotonic NaCl to each flap as a control group).Measuring the contents of VEGF and TXB2, counting the neo-microvasculardensity. Detect the expression of flap tissue VEGFmRNA by FluorescentRT-PCR. Counting the survival rates in seventh day.Result:Histopathological observation of the flaps (day 7)In the natural hirudin group, skin flaps epidermis complete, no atrophy wasobserved, only mild hyperkeratosis, no significant inflammatory cell infiltrationto dermis and subcutaneous tissue and no tissue edema. There was an increase insubdermal microvascular density. Epidermis atrophy is not obvious inrecombinant hirudin group. Subcutaneous tissue was mildly edematous,inflammatory cell infiltrated slightly heavier. In contrast, there was increased insubcutaneous edema, inflammatory cell infiltration, local skin ulceration, andonly small amount of subdermal microvessels in the control group. Thehistopathological features of the recombinant hirudin group were intermediateamong the three groups.The VEGF positive vessel density in flapPostoperative day 3, 5, 7, VEGF staining the number of positive vessels: Thelargest number of VEGF positive vessels staining was group A, followed byGroup B and Group C was the least. Each group pairwise comparisons, P<0.05,the difference was statistically significant. Detect the expression of flap tissue VEGF mRNAPostoperative day 3, 5 and 7: The largest number of VEGF mRNAexpression was group A, followed by Group B and Group C was the least. Bothtreatment groups have significantly higher numbers of VEGFmRNA comparedto control group (P<0.05).TXB2expression in random skin flap: Postoperative day 3, 5, control grouphas significantly higher numbers of TXB2compared to treatment groups(P<0.05), the difference was statistically significant.Group A was highernumbers of TXB2compared to group B (P>0.05), the difference was notstatically significant.Surface area of flap survival: natural hirudin group (A): 26.64±2.24(cm2), recombinant hirudin group (B): 23.64±2.02 (cm2), control group (C):20.71±1.41 (cm2); flap survival rate (%): natural hirudin group (A): 88.87±2.24, recombinant hirudin group (B):79.97±2.02, control group (C):69.07±1.42. Pairwise comparison between three groups, P <0.05, the difference wasstatistically significant.Conclusion: VEGF expression in random skin flap can be increased and TXB2can be reduced by natural hirudin and recombinant hirudin which are conduciveto angiogenesis and can improve the survival rate of random skin flap. We canconclude that natural hirudin and recombinant hirudin which are conducive tovenous congestion and can improve the survival rate of random skin flap.