The Effects Of Botulinum Toxin A On Survival Of Rat Superlong Flap

Objective:To observe the botulinum toxin A (botulinum toxin A, BTX-A)on survival of rat superlong flap, evaluate the feasibility of chemical delay of botulinum toxin A and its best injection location.Methods:54 male Wister rats as experimental objects.Rats were randomly divided into 3 groups, the delayed operation group (group A), respectively, the BTX-A group (B1 flap pedicle injection group, B2 flap distal injection group) and normal saline control group (C1 flap pedicle injection group, C2 flap distal injection group), observation period for A week.Intraperitoneal injection of 45 mg/kg of chloral hydrate to anesthesia animals.Flap of arrogance’s abdomen, size 5 cm* 2 cm, distal flap across the abdomen middle line 2 cm, the flap contains shallow abdominal arteries.First step, the surgical delay group incisied according to the preoperative design drawing line, seperated flap to meat membrane layer, and careful operation, avoid destroying meat vascular membrane layer, completely stop bleeding after orthotopic suture. B1 injecting botulinum toxin A (1 ml,2.5 U/ml) to skin near the vascular pedicle division, C1 injecting saline solution. B2 away 1 cm from both sides of abodomen Central Line, flap was divided into 3 trisection, subcutaneous injecting botulinum toxin A (1 ml,2.5 U/ml), C2 injecting saline solution.The second step, to observe for a week after the flap, suture in situ.By observing each flap survival rate (laser doppler blood flow meter, photographic image analysis), the density of capillaries, arteriovenous vascular caliber, the density of CD31 and VEGF expression, compare each flap survival situation.Results1. Gross observation of macroscopic observation survival flaps are soft, rosy, acupuncture bleeding;Necrosis of that arequalitative hard, black, no bleeding when acupuncture;not full-thickness necrosis of skin flap performance given in between.7 days after operation, compared with control group, botulinum toxin A and delayed surgery group of skin flap necrosis area is lesser, surgical delay necrosis minimally, tissue edema is lighter.2. The survival rate of skin flap botulinum toxin A and delayed surgery group flap survival area is larger.Botulinum toxin A group B1 survival area was 54.73±1.39%, B2 52.26±1.36%, delay surgery group survival rate was 58.56±0.82%. The control group C1 46.31±1.26%, C2 47.27%±1.43.The botulinum toxin A flap pedicle skin flap necrosis of injection group area compared with larger area of skin flap necrosis distal injection group.3. The vascular density detection BTX-A and delayed surgery group vascular density increased, compared with control group, increase more apparent density, flap pedicle division injection distal vascular density than flap injection group.4. Detection of VEGF protein, CD31 immunohistochemical staining visible BTX-A group and the group delay distribution of flap surgery more tan particles in the flap of the epidermis, dermis and hair follicle gland epithelial cells had strong positive expression;The distribution of VEGF immune positive cells in the control group in the middle flap is thin.Vascular pedicle tan particle distribution department injection group compared to flap distal injection group is relatively sparse.5. Testing results of laser doppler the most same as general observations, BTX-A injection group and delayed surgery group’s blood flow value higher than control group.6. Arteriovenous vascular caliber delay surgery and BTX-A group arteriovenous caliber bigger than normal saline control group, BTX-A group’s vein caliber bigger than surgery group.In the Soaked adrenaline saline group’s specimens, the BTX-A group’s arterial diameter bigger than that not, rather vein results with no difference.Conclusion:①the results show that botulinum toxin A can inhibit flap sympathetic nerve of microcirculation system, has certain protective effect on distal ischem flap, promoting its survival;②the flap Distal injecte botulinum toxin A can increase the survival length of the flap; ③flap pedicle Injecte botulinum toxin A can also increase the survival length of the flap, but the effect is better than flap distal injection group;④the delay effect of botulinum toxin A can increase the survival length of the flap, but its effect still not as good as the surgical delay, cannot replace surgery delay.