Effects of combined natural hirudin and hyperbaric oxygen therapy on survival of transplanted random-pattern skin flap in rats
Experimental study published in Chinese Journal of Reparative and Reconstructive Surgery (2018)
Abstract
OBJECTIVE: To investigate the effect of natural hirudin combined with hyperbaric oxygen therapy on the survival of transplanted random-pattern skin flap in rats. METHODS: A 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. RESULTS: Partial 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). CONCLUSION: Hyperbaric 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. 目的: 探讨天然水蛭素联合高压氧治疗对大鼠随意皮瓣成活的影响。. 方法: 取 72 只 SD 大鼠，于背部制备面积为 10.0 cm×2.5 cm 的随意皮瓣移植模型后，随机分为 4 组（ n=18）。对照组术后即刻及之后 4 d 内注射生理盐水，高压氧组注射生理盐水同时行高压氧治疗，水蛭素组仅注射天然水蛭素，联合组注射天然水蛭素同时行高压氧治疗。术后大体观察皮瓣成活情况，第 6 天计算皮瓣成活率；第 2、4 天取材，HE 染色观察皮瓣组织学变化；免疫组织化学染色检测皮瓣微血管密度（microvessel density，MVD）以及 TNF-α 表达水平。. 结果: 术后各组皮瓣均出现部分坏死，其中联合组皮瓣成活最佳；术后第 6 天高压氧组、水蛭素组及联合组皮瓣成活率明显高于对照组，联合组高于水蛭素组、高压氧组，比较差异有统计学意义（ P<0.05）；水蛭素组与高压氧组比较，差异无统计学意义（ P>0.05）。组织学观察示，术后第 2 天，水蛭素组、高压氧组及联合组微血管结构较对照组多，各组均见炎性细胞浸润；第 4 天，高压氧组、水蛭素组及联合组中仍可见较多微血管形成，对照组中见大量炎性细胞浸润，其余各组炎性细胞均较术后第 2 天时明显减少。免疫组织化学染色观察示，术后第 2 天，高压氧组、水蛭素组及联合组 MVD 均显著高于对照组、TNF-α 蛋白表达量显著低于对照组（ P<0.05）；高压氧组、水蛭素组及联合组以上指标比较，差异无统计学意义（ P>0.05）。术后第 4 天，高压氧组、水蛭素组及联合组 MVD 均显著高于对照组，联合组及水蛭素组高于高压氧组，比较差异有统计学意义（ P<0.05），联合组及水蛭素组间比较差异无统计学意义（ P>0.05）；高压氧组、水蛭素组及联合组 TNF-α 蛋白表达量显著低于对照组，联合组低于水蛭素组及高压氧组，比较差异有统计学意义（ P<0.05），水蛭素组及高压氧组间比较差异无统计学意义（ P>0.05）。. 结论: 高压氧和天然水蛭素干预均能提高随意皮瓣移植后成活率，且两者联合发挥协同效应，可能与促进血管生成和减轻炎性反应有关。.
Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.
Summary
Rat random-pattern flap model showing combined natural hirudin + hyperbaric oxygen produced greater flap survival than either monotherapy, with reduced inflammation and improved vascularization.
Why This Matters for Hirudotherapy
This study investigated the effect of natural hirudin combined with hyperbaric oxygen therapy on survival of transplanted random-pattern skin flaps in 72 Sprague-Dawley rats, divided into control, hyperbaric oxygen, natural hirudin, and combined treatment groups. The combined group showed the highest flap survival rate, and both monotherapies significantly improved survival versus control; combined therapy also significantly increased microvessel density and reduced TNF-α expression, suggesting synergy via angiogenesis promotion and inflammation reduction. This is relevant to ASH's domain as it directly uses natural hirudin in a surgical reconstructive context. CAVEAT: This is an animal study in rats with no human data; isolated hirudin was injected rather than leeches applied, so it does not directly model hirudotherapy. The abstract does not describe hirudin's biological origin.
Citation
Effects of combined natural hirudin and hyperbaric oxygen therapy on survival of transplanted random-pattern skin flap in rats.
Cai J et al. · Zhongguo xiu fu chong jian wai ke za zhi, 2018
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