Objective To explore the effects of natural hirudin on the survival of dorsal random flap after early pedicle division in rats. Methods Thirty-eight adult Wistar rats, male or female, weighing 220-280 g, were selected and randomly divided into natural hirudin group (experimental group, n=19) and normal saline group (control group, n=19). The dorsal random flap of 9 cm × 3 cm in size was prepared on the back of the rats. Six symmetrical injection points were selected at 2, 4, and 8 cm from the pedicle, 0.5 mL (3 ATU) natural hirudin and equivalent normal saline were injected in experimental group and control group respectively every day to the end of the experiment. After 4 days, the pedicles were cut. The flap was observed, and the ratio of flap survival area was measured at 7 days after pedicle division. At immediately after flap preparation, at 1 day before pedicle division, and at 3 and 7 days after pedicle division, the specimens were harvested for histological staining, immunohistochemical staining, microvessel density (MVD) measurement, and detection of vascular endothelial growth factor (VEGF) mRNA expression by fluorescent quantitative RT-PCR. Results All rats of 2 groups survived to the completion of the experiment. After pedicle division, the flap necrosis area of experimental group was smaller than that of control group; at 7 days, the ratio of flap survival area in experimental group was 85.366% ± 2.872%, and was significantly higher than that in control group (75.252% ± 3.455%) (t=7.117, P=0.000). Histological staining showed that no significant difference was found in the number of capillaries between 2 groups at immediately after flap preparation; at 1 day before pedicle division and at 3 and 7 days after pedicle division, the capillary number of experimental group was significantly more than that of control group. Immunohistochemical staining showed that CD34 positive cells were observed in 2 groups; MVD of experimental group was significantly higher than that of control group at 1 day before pedicle division, and at 3 and 7 days after pedicle division (P lt; 0.05). At 7 days after pedicle division, the VEGF mRNA expression was 7.122 ± 0.503 in experimental group, and was 5.655 ± 1.174 in control group, showing significant difference (t=3.633, P=0.003). Conclusion Natural hirudin can promote the formation of new blood vessels, improve the blood supply of the flap, and increase the survival of random flap after early pedicle division by increasing VEGF expression.
Objective Dexamethasone (DXM) can regulate the balance of neutrophil and cytokine and enhance the ischemia-reperfusion tolerance of the skin flap; amlodipine besylate (AB) can selectively expand the peripheral blood vesselsand rel ieve the vascular smooth muscle spasm. To investigate the percutaneous penetration abil ity of DXM/AB compound gel and evaluate its effect on survival of ischemic skin flap. Methods Sodium carboxymethylcellulose was used to make blank gel, which was mixed in DXM, AB, azone (AZ), and progylene glycol (PG) respectively to make the compound gel containing 0.3%DXM/0.5%AB only (group D), the compound gel containing 3%AZ/2%PG, 3%AZ, and 2%PG (groups A, B, and C), the 0.3%DXM gel containing 3%AZ/2%PG (group E), the 0.5%AB gel containing 3%AZ/2%PG (group F). The accumulative penetration of DXM and AB in compound gel, 0.3%DXM gel, 0.5%AB gel through excised rat skin and its penetration within flap tissue were investigated by ultraviolet spectrophotometry. Fifty SD rats were selected to make 100 mm × 10 mm random flap at the back, and were randomly divided into 5 groups according to different gels which were used to treat flaps (n=10): compound gel group (group A1), 0.3%DXM gel group (group B1), 0.5%AB gel group (group C1), blank gel group (group D1), and peritoneal injection of DXM (5 mg/kg) and AB (2 mg/kg) (group E1). The survival area of ischemic random skin flap was measured on the 7th day by planimetry. Twenty-four SD rats were selected to make 100 mm × 10 mm random flap at the back, and were randomly divided into 2 groups (n=12). The accumulative penetration of DXM and AB within skin flap were also detected at 2 and 6 hours after appl ication of 2 g of compound gel containing 3%AZ/2%PG (group A2) and peritoneal injection AB (2 mg/kg) / DXM (5 mg/kg) (group B2). Results The accumulative penetration of DXM and AB in compound gel were increased in time-dependent manner (P lt; 0.05), and it was the highest in group A, and was significantly higher than that in group B and group C (P lt; 0.01), but there was no significant difference when compared with group E or group F (P gt; 0.05). The accumulative penetration of DXM and AB in groups A, B, and C were significant higher than that in group D (P lt; 0.05). After 7 days, the survival area of flaps in groups A1, B1, C1, D1, and E1 were (695.0 ± 4.6), (439.3 ± 7.1), (477.5 ± 14.5), (215.2 ± 3.8), and (569.4 ± 9.7) mm2, respectively; group A1 was significantly higher than other groups (P lt; 0.05). After 2 and 6 hours, the quantities of DXM and AB in skin flap of group A2 were significantly higher than that of group B2 (P lt; 0.05). Conclusion In 0.3%DXM/0.5%AB compound gel, DXM and AB might penetrate into skin tissue, which could significantly increase the survivalarea of ischemic skin flap.
Objective To investigate the effects of ecdysterone on the survival of the dorsal random-pattern skin flap with large length-to-width ratio in rats and its possible mechanisms. Methods Twenty-four healthy adult SD rats (male and/or female) weighing 200-250 g were randomly divided into the experimental group and the control group (n=12 per group).A caudally based dorsal random pattern skin flap, measuring 8 cm × 2 cm, was symmetrically raised. Ecdysterone (5 mg/kg) and normal sal ine (5 mg/kg) were injected into the abdominal cavity of rats in the experimental group and the control group at 10 minutes before operation and from the first to the fifth day after operation, respectively. The general condition of the rats was observed after operation. At 7 days after operation, the survival rate of the flap was detected, the superoxide dismutase (SOD) activity and the malonyldialdehyde (MDA) level were tested, HE and immunohistochemistry staining observation of the flap were performed. VIII factor dried microvessels in the middle part of the flap (4 cm far away from pedicle) were counted. Results All the rats survived until the end of the experiment. At 7 days after operation, the survival rate of the flap was 62.323% ± 7.046% in the experimental group and 47.753% ± 2.952% in the control group (P lt; 0.001); SOD activity was (54.560 ± 4.535) U/mgprot in the experimental group and (23.962 ± 3.985) U/mgprot in the control group (P lt; 0.001); MDA level was (8.445 ± 0.992) nmol/mgprot in the experimental group and (14.983 ± 0.929) nmol/mgprot in the control group (P lt; 0.001). Histology observation: compared with the control group, the inflammatory cells infiltration was less and the hyperplasia of fibers was more obvious in the experimental group. The microvessel counting in the middle part of the flap was 17.817 ± 2.420 in the experimental group and 8.967 ± 2.000 in the control group (P lt; 0.001). Conclusion Perioperative intraperitoneal injection of ecdysterone can promote the survival of the random-pattern skin flaps with large length-to-width ratio. Its mechanism may be related to its effects of improving SOD activity, decreasing l ipid peroxidation, and promoting angiogenesis of skin flaps.
Objective To investigate the effects of glutathione (GSH) on survival of the random skin flap in rats and the probable mechanism that contribute to this effect. Methods Twenty SD rats with 200-250 g in weight, were randomly divided into the experimental group and control group(n=10). Random flap of 8 cm×2 cm in size was made on the back of each rat with the pedicel on the angular of the scapular. GSH(250 mg/kg) and NS of the same dose were injected into the abdominal cavity of rats in the experimental groupand the control group immediately after the operative, 1st and 2nd days respectively. The rats were killed on the 7th day after the operation. The tissue pathology, the survival rate of the flap, the superoxide dismutase(SOD) activity and malonyldialdehyde (MDA) level were compared between two groups. Results The mean survival rate of the flap on the 7th day in the experimental group（56.77%±10.67%） was higher than that in the control group(40.16%±7.12%)(Plt;0.05).SOD activity in experimental group （306.06±84.87 U/mgprot）was higher than that in the control group （224.79±27.12 U/mgprot）, while MDA level （3.835±0.457 nmol/mgprot）was lower than that in the control group (6.127±0.837 nmol/mgprot)(Plt;0.05). Histological observation showed that the neutrophil infiltration was less in experimental group than that in the control group; that the experimental group was surperior to the control group in angiogenesis, fibroblasts, fair cells and cuaneous gland. Conclusion The intraperitoneal use of GSH may promote the survival rate of the random flaps and the possible mechanism for improvement may lies in that the GSH can reduce the level of oxygen free radical and lipidperoxidation,and lessen neutrophil infiltration.
Abstract A doublepediculated randomized flap parallal to the longitudinal axis of the extremity was designed. The skin and the subcutaneous tissue superficial to the deep fascia was incised on both sides of the axis of the flap. The subcutaneous tissue was separated from the deep fascia. The two ends of the flap should not be incised, thus a bipolar doulepediculated flap was formed. A silicone membrane was placed under the flap toobstruct the blood supply of the flap partially so that the delay effect was created. After 10～14 days, one end of the pedicles was divided so thata pediculated superlong randomized flap was formed. The flap was transferred to cover the wound on the recipient area. The wound on the donor site was closed directly or covered by split skin graft. From Janurary 1991 to July 1994,this technique was used in 8 patients (male 6, female 2). The age averaged 30 years old. These cases included 5 cases of fracture complicated with skin defect or scar on leg and 3 cases of crashing injury of the lower extremity. The length and width of the flap and the width of the pedicle ranged from 20cm×7cm×4cm to 29cm×10cm×3cm respectively. The flaps were completely survived after operation. The wound and the exposed deep tissues such as bone, tendon, nerve and vessels were covered and repaired. As a consequence that the pediculated superlong randomized flap was effective in repairing soft tissue defect.
A comperative study Of the thickness,the ratio of length to width and the division time of the pediele between the randomized defatted skin flap and the randomized conventional skin flap wasundertaken in 12 pigs,weighing 25-30 kg.Two tpe of defatted edicled skin flape were made,inwhich,one preserved a thickness of 2-3mm adipose tissue and the Other one third of the superficialfascial beneath the subeutaneous vascular network.The resuIts indicated that after division of thepedicles on the ...
The ultra length and width random calf fasciocutaneous flaps whose blood supply came from the calf fasciocutaneous vascular network were transposed in 9 cases for the treatment of severe trauma of leg. All of the flaps survived except one having necrosis of the distal fourth. The length and width of the flap to the width of the pedicle were 6.1∶1 and 2.7∶1 respectively. Properly extended the area and decreased of blood perfusion of the flan would reduce the burden of the venous backflow to the flap relatively. The abundant vascular networks of the calf fasciocutaneous flap was a very important factor that this type of flap would possibly survive.
Eighteen cases with hand injury were repaired by 20 pediclcd over-thin skin flaps with success. The area of pedicled skin flap is from 1.5×1.2 to 12×8.5cm. The pedicles of skin flap were divided at 5-7 days postoperation after clamp training of the pedicle, and the flap all survived. The operative method is introduced and the mechanism of skin flap survival is discussed.
ObjectiveTo investigate the effect of natural hirudin combined with hyperbaric oxygen therapy on the survival of transplanted random-pattern skin flap in rats.MethodsA random-pattern skin flap in size of 10.0 cm×2.5 cm was elevated on the dorsum of 72 Sprague Dawley rats. Then the 72 rats were randomly divided into 4 groups (n=18) according to the therapy method. At immediate and within 4 days after operation, the rats were treated with normal saline injection in control group, normal saline injection combined with hyperbaric oxygen treatment in hyperbaric oxygen group, the natural hirudin injection in natural hirudin group, and the natural hirudin injection combined with hyperbaric oxygen treatment in combined group. The flap survival was observed after operation, and survival rate was evaluated at 6 days after operation. The skin samples were collected for histological analysis, microvessel density (MVD) measurement, and evaluation of tumor necrosis factor α (TNF-α) expression level by the immunohistochemical staining at 2 and 4 days after operation.ResultsPartial necrosis occurred in each group after operation, and the flap in combined group had the best survival. The survival rate of flap was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, and in combined group than in hyperbaric oxygen group and natural hirudin group (P<0.05). There was no significant difference between hyperbaric oxygen group and natural hirudin group (P>0.05). At 2 days, more microvascular structure was observed in hyperbaric oxygen group, natural hirudin group, and combined group in comparison with control group; while plenty of inflammatory cells infiltration in all groups. At 4 days, the hyperbaric oxygen group, natural hirudin group, and the combined group still showed more angiogenesis. Meanwhile, there was still infiltration of inflammatory cells in control group, inflammatory cells in the other groups were significantly reduced when compared with at 2 days. At 2 days, the MVD was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group (P<0.05); the expression of TNF-α was significantly lower in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group (P<0.05). There was no significant difference in above indexes between hyperbaric oxygen group, natural hirudin group, and combined group (P>0.05). At 4 days, the MVD was significantly higher in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, in natural hirudin group and combined group than in hyperbaric oxygen group (P<0.05). The expression of TNF-α was significantly lower in hyperbaric oxygen group, natural hirudin group, and combined group than that in control group, in combined group than in natural hirudin group and hyperbaric oxygen group (P<0.05).ConclusionHyperbaric oxygen and natural hirudin therapy after random-pattern skin flap transplantation can improve the survival of flaps. Moreover, combined therapy is seen to exhibit significant synergistic effect. This effect maybe related to promotion of angiogenesis and the reduction of inflammation response.