Preventive effects of chitosan on peritoneal adhesion in rats

AIM： To study the effects of chitosan gel and blending chiston/gelatin film on preventing peritoneal adhesion in rats. METHODS： SD rats were randomly divided into 2 groups, group A treated with chitosan gel and group B with blending chiston/gelatin film. In group A, rats were randomly subdivided into 3 subgroups as groups A1, A2 and A3, and different methods were used to induce peritoneal adhesions at the dead end of vermiform process in each group as follows： Group A1 with trauma, A2 with talc powder and A3 with ligation of blood vessel. In each subgroup, rats were redivided into control group and experimental group whose treated vermiform processes were respectively coated with chitosan gel and normal saline immediately after the adhesioninduced treatments. In group B, all the rats received traumatic adhesion-induced treatments and then were randomly divided into 4 groups （groups B1, B2, B3, B4）. Group B1 served as control group and were coated with normal saline in the vermiform processes immediately after the treatments, and groups B2, B3 and B4 with 100% chitosan film, chitosan film containing 10% gelatin and chiston film containing 50% gelatin, respectively. At 2 and 4 wk after the above treatments, half of the rats in each terminal group were belly opened, and the peritoneal adhesive situation was graded and histopathological changes were examined. RESULTS： （1） In group A, regarding peritoneal adhesion situation： At both 2 and 4 wk after the treatments, for groups A1 and A3, the adhesive grades of experimental groups were significantly lower than those of the control group （2 wk： H = 4.305, P 〈 0.05 for A1, H = 6.743, P 〈 0.01 for A3; 4 wk： H = 4.459, P 〈 0.05 for A1, H =4.493, P 〈 0.05 for A3）. However, of group A2, there was no significant difference between the experimental and control groups （2 wk： H = 0.147, P 〉 0.05; 4 wk： H = 1.240, P 〉 0.05）. Regarding pathological changes： In groups A1 and A3, the main pathological change was fibroplasia. In group A2, the main changes were massive foreign-body giant cell reaction and granuloma formation with fibroplasia of different degrees. （2） In group B, regarding degradation of film： With increase of the blended gelatin concentration, degrading speed of the film accelerated significantly. Regarding peritoneal adhesion situation： At both 2 and 4 wk after the treatments, the adhesive grades of B1 were the lowest among the four subgroups of B （2 wk： H = 29.679, P 〈 0.05; 4 wk： H = 18.791, P 〈 0.05）. At 2 wk after the treatments, the grades of group B2 were significantly lower than that of groups B3 and B4 （H = 4.025, P 〈 0.05 for B2 vs B3; H = 4.361, P 〈 0.05 for B2 vs B4）. At 4 wk, there were no significant differences of the grades between groups B2, B3 and B4. Regarding pathological changes： Inflammatory cell infiltration and fibroplastic proliferation were observed in the local treated serous membranes, which was the mildest in group B1. Slight foreign-body giant cell reactions were also found in groups B2, B3, and B4. CONCLUSION： （1） Chitosan gel has preventive effect on traumatic or ischemic peritoneal adhesion, but no obvious effect on foreign body-induced peritoneal adhesion. （2） Chitosan film may exacerbate the peritoneal adhesion. Blending with gelatin to chitosan film can accelerate the degradation of the film, but can simultaneously facilitate the formation of peritoneal adhesion.

Prevention of peritoneal adhesions:A promising role for gene therapy

Adhesions are the most frequent complication of abdominopelvic surgery,yet the extent of the problem,and its serious consequences,has not been adequately recognized.Adhesions evolved as a life-saving mecha-nism to limit the spread of intraperitoneal inflammatory conditions.Three different pathophysiological mechanisms can independently trigger adhesion formation.Mesothelial cell injury and loss during operations,tissue hypoxia and inflammation each promotes adhesion formation separately,and potentiate the effect of each other.Studies have repeatedly demonstrated that interruption of a single pathway does not completely prevent adhesion formation.This review summarizes the pathogenesis of adhesion formation and the results of single gene therapy interventions.It explores the prom-ising role of combinatorial gene therapy and vector modif ications for the prevention of adhesion formation in order to stimulate new ideas and encourage rapid advancements in this field.

Experimental Observation on the Effects of Different Chitosan on Preventing Traumatic Peritoneal Adhesion in Rats

objective:The effects of different chitosan on preventing traumatic peritoneal adhesion in rats was studied in this paper. METHODS: 96 SD rats with injured vermiform process were randomly divided into 4 groups as follows: group A without any treatment as control, group B treated with chitosan gel, group C treated with pure chitosan film and group D treated with chiston film containing 50% gelatin. 2 and 4 weeks after surgery, 12 rats in each group were respectively belly opened to observe chitosan degradation and evaluate peritoneal adhesion, and the adhesive vermiform processes tissues were histopathologically observed. RESULTS: 1.Degradation in the group D was faster than that in the group C but slower than that in the group B. 2. 2 weeks after surgery the adhesion in the group B was milder than that in the control group(goup A) (P<0.05), but that in the group C and D (both P<0.05) were more severe than that in the control group . 3. 4 weeks after surgery , the adhesion in the group B was milder than that in the control group (P<0.05), but that in the group C and D (both P<0.05) were more severe than that in the control group , whereas, there was no significant difference between adhesion in the group C and group D (P>0.05). 4.Histopathological examinaiton indicated that: 2 weeks after surgery ,inflammatory cell infiltration and fibroplastic proliferation dominated in local lesion and the response was most severe on the serous coat, furthermore, the response in the control group was more severe than that in the group B, but milder than that in the group C and D; 4 weeks after surgery, fibroplastic proliferation dominated in local lesion in each group , moreover, the response in the control group was more severe than that in the group B but milder than that in the group C and D. What’s more, integrated fibrous membrane formed around implanted materials in the group C and D, and the fibrous membranes were thinner in the group C than that in the group D. CONCLUSION: 1.Chitosan gel has perfect effect in protecting traumatic peritoneal adhesion in rats. 2.Pure chitosan film could exacerbate peritoneal adhesion and chitosan containing gelatin could exacerbate peritoneal adhesion further.

Peritoneal adhesions after laparoscopic gastrointestinal surgery

Although laparoscopy has the potential to reduce peritoneal trauma and post-operative peritoneal adhesion formation, only one randomized controlled trial and a few comparative retrospective clinical studies have addressed this issue. Laparoscopy reduces de novo adhesion formation but has no efficacy in reducing adhesion reformation after adhesiolysis. Moreover, several studies have suggested that the reduction of de novo post-operative adhesions does not seem to have a significant clinical impact. Experimental data in animal models have suggested that CO2 pneumoperitoneum can cause acute peritoneal inflammation during laparoscopy depending on the insufflation pressure and the surgery duration. Broad peritoneal cavity protection by the insufflation of a low-temperature humidified gas mixture of CO2, N2O and O2 seems to represent the best approach for reducing peritoneal inflammation due to pneumoperitoneum. However, these experimental data have not had a significant impact on the modification of laparoscopic instrumentation. In contrast, surgeons should train themselves to perform laparoscopy quickly, and they should complete their learning curves before testing chemical anti-adhesive agents and anti-adhesion barriers. Chemical anti-adhesive agents have the potential to exert broad peritoneal cavity protection against adhesion formation, but when these agents are used alone, the concentrations needed to prevent adhesions are too high and could cause major post-operative side effects. Anti-adhesion barriers have been used mainly in open surgery, but some clinical data from laparoscopic surgeries are already available. Sprays, gels, and fluid barriers are easier to apply in laparoscopic surgery than solid barriers. Results have been encouraging with solid barriers, spray barriers, and gel barriers, but they have been ambiguous with fluid barriers. Moreover, when barriers have been used alone, the maximum protection against adhesion formation has been no greater than 60%. A recent small, randomized clinical trial suggested that the combination of broad peritoneal cavity protection with local application of a barrier could be almost 100% effective in preventing post-operative adhesion formation. Future studies should confirm the efficacy of this global strategy in preventing adhesion formation after laparoscopy by focusing on clinical end points, such as reduced incidences of bowel obstruction and abdominal pain and increased fertility.

Cytokine orchestration in post-operative peritoneal adhesion formation

Peritoneal adhesions are a near inevitable occurrence after laparotomy and a major cause of both patient and physician misery. To date, clinical attempts at their amelioration have concentrated on manipulating the physical factors that affect their development despite a wealth of experimental data elucidating the molecular mechanisms that underlie their initiation, development and maturation. However, the advent of targeted, specific anti-cytokine agents as directed therapy for inflammatory and neoplastic conditions raises the prospect of a new era for anti-adhesion strategies. To harness this potential will require considerable cross-disciplinary collaboration and that surgeon-scientists propel themselves to the forefront of this emerging fi eld.

Effect of Monocyte Chemotactic Protein-1 on the Intraperitoneal Adhesion Formation

In order to study the role of monocyte chemotactic protein-1 (MCP-1) in the intra-peri- toneal adhesion formation, 23 infertile patients undergoing laparoscopic operation were divided into two groups: experimental group including 12 patients with intra-peritoneal adhesion and control group including 11 patients without intra-peritoneal adhesion. Peritoneal fluid (PF) and peritoneum were collected from these patients during laparoscopic examination. The expression levels of MCP-1 protein and MCP-1 mRNA were detected by using enzyme-linked immunosorbent assay (ELISA) and dot blot analysis method respectively. It was found that the levels of MCP-l protein in PF of the patients with peritoneal adhesion were significantly higher than in the control group (0.44±0. 11 ng/ ml vs 0. 19±0.09 ng/ml respectively, P<0. 01). The level of MCP-l mRNA in the peritoneum of the patients with peritoneal adhesion was significantly higher than in the control group (48. 61±3. 72 vs 19.87±2.54 respectively, P<0. 01). It was suggested that MCP-1 might play a role in the adhe- sion formation, and chemotactic cytokines expressing in the peritoneal mesothelial cells might be take part in the process.

Identification of candidate biomarkers correlated with pathogenesis of postoperative peritoneal adhesion by using microarray analysis

BACKGROUND Postoperative peritoneal adhesion(PPA),characterized by abdominal pain,female infertility,and even bowel obstruction after surgery,has always been a major concern.The occurrence and formation of adhesion are from complex biological processes.However,the molecular mechanisms underlying the basis of microarray data profile,followed by peritoneal adhesion formation,are largely unknown.AIM To reveal the underlying pathogenesis of PPA at the molecular level.METHODS The gene expression profile was retrieved from the Gene Expression Omnibus database for our analysis.We identified a panel of key genes and related pathways involved in adhesion formation using bioinformatics analysis methods.We performed quantitative PCR and western blotting in vivo to validate the results preliminarily.RESULTS In total,446 expressed genes were altered in peritoneal adhesion.We found that several hub genes(e.g.,tumor necrosis factor,interleukin 1 beta,interleukin 6,CX-C motif chemokine ligand 1,C-X-C motif chemokine ligand 2)were marked as significant biomarkers.Functional analysis suggested that these genes were enriched in the Toll-like receptor signaling pathway.According to the Kyoto Encyclopedia of Genes and Genomes pathway and published studies,TLR4,myeloid differentiation primary response protein 88(MyD88),and nuclear factor kappa B(NF-κB)played essential roles in Toll-like signaling transduction.Here,we obtained a regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion involved in the pathogenesis of postoperative adhesion.The results of the microarray analysis were verified by the animal experiments.These findings may extend our understanding of the molecular mechanisms of PPA.CONCLUSION The regulatory evidence chain of TLR4/MyD88/NF-κB/inflammatory cytokines/peritoneal adhesion may play key roles in the pathogenesis of PPA.Future studies are required to validate our findings.

Abdominal and pelvic adhesions: Possible role of leiomyomas and skin scar anomaly in profiling high risk patients

Background and aims: Adhesions can cause important morbidity including abdominal and pelvic pain, intestinal obstructions, and infertility. When adhesions are formed, there is no efficient method, nowadays, to resolve them, thus the reduction of their prevalence relies on the prevention. Profiling high risk patients for abdominal and pelvic adhesions (APA) is an important step to this prevention. The risk factors of adhesions in our institution, the association between APA, leiomyomas and skin scar anomaly (SSA) were investigated. Methods: A cross-sectional study was conducted from March 1st to June 30th 2013 including patients who underwent laparotomy or laparoscopy. Patients’ characteristics, presence of a SSA and leiomyomas, as related to adhesions, were analyzed. Student’s t, Pearson’s Khi-square, Fisher’s Exact, Mann-Whitney tests and logistic regression were used. P values < 0.05 were considered statistically significant. Results: The frequency of adhesions was 41.74%. Patients had a mean age of 32.69 ± 8.94 years. Those with a previous abdominal surgery (PAS), SSA and leiomyomas had respectively 12 times [OR: 11.98, CI95 (4.63 - 30.97)], 3 times [OR: 2.79, CI95 (1.16 - 6.71) and 2.5 times [(OR: 2.49, CI95 (1.07 - 5.78)] more adhesions. In logistic regression, a PAS and leiomyomas remained associated significantly to adhesions with p = 0.000 and p = 0.037 respectively. Conclusion: In peritoneal adhesions, leiomyomas and SSA are other factors that may allow a cautious selection of high risk patients who must benefit from particular attention during surgery. Further well designed studies are necessary to investigate the accurate clinical relation among those three conditions.

Berberine prevents primary peritoneal adhesion and adhesion reformation by directly inhibiting TIMP-1

Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and represent the major cause of postsurgical morbidity.Enterolysis at repeat surgeries induces adhesion reformation that is more difficult to prevent than primary adhesion.Here we studied the preventive effects of different approaches of berberine treatment for primary adhesion,and its effects on adhesion reformation compared to Interceed.We found the primary adhesion was remarkably prevented by berberine through intraperitoneal injection 30 min before abrasive surgery(pre-berberine)or direct addition into injured cecum immediately after the surgery(inter-berberine).Rats with adhesion reformation had a more deteriorative collagen accumulation and tissue injury in abrasive sites than rats with primary adhesion.The dysregulated TIMP-1/MMP balance was observed in patients after surgery,as well as adhesion tissues from primary adhesion or adhesion reformation rats.Inter-berberine treatment had a better effect for adhesion reformation prevention than Interceed.Berberine promoted the activation of MMP-3 and MMP-8 by directly blocking TIMP-1 activation core,which was reversed by TIMP-1 overexpression in fibroblasts.In conclusion,this study suggests berberine as a reasonable approach for preventing primary adhesion formation and adhesion reformation.

Evaluation of the effectiveness of alginate-based hydrogels in preventing peritoneal adhesions

Infertility and intestinal blockage are just two examples of the postoperative consequences that can arise from peritoneal damage,which can also result in severe peritoneal fibrosis and peritoneal adhesions.Peritoneal adhesions are still not effectively treated,and both pharmaceutical therapy and biomaterial barriers have only had modest preventative effects.In this work,we looked into the effectiveness of in-place injectable sodium alginate hydrogel for peritoneal adhesion prevention.The findings demonstrated that sodium alginate hydrogel promoted human peritoneal mesothelial cell proliferation and migration,prevented peritoneal fibrosis by suppressing the production of transforming growth factor-β1,and,most importantly,promoted mesothelium self-repair.These findings imply that this brand-new sodium alginate hydrogel is a good candidate material for peritoneal adhesion prevention.

腹膜粘连的分子机制研究进展

腹膜粘连是术后最常见的并发症之一。腹膜粘连的形成是一个多因素、多阶段的复杂过程,多种炎症细胞及其分泌的细胞因子促使炎症反应慢性化、凝血级联反应的启动和纤维蛋白过度沉积,最终导致病理性腹膜粘连带形成。近年来的研究还突出了非编码RNA在腹膜粘连中的重要作用。

丹酚酸B对术后腹膜粘连大鼠的抗粘连作用

目的研究丹酚酸B(SAB)对大鼠腹膜粘连防治效果其作用机制。方法采用盲肠钳夹和腹膜损伤方法建立大鼠腹膜粘连模型,通过粘连等级综合评分法计算大鼠术后粘连得分,并取腹壁和盲肠壁组织切片进行苏木精-伊红(HE)染色,观察组织病理结构变化。实时荧光定量PCR检测术后大鼠粘连组织基质金属蛋白酶-9(MMP-9)和基质金属蛋白酶抑制因子-1(TIMP-1)mRNA的表达。酶链免疫吸附法(ELISA)检测术后大鼠血清转化生长因子-β1(TGF-β1)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、大鼠腹壁组织或粘连组织MMP-9和TIMP-1表达水平。结果与模型组相比,SAB中、高剂量组(40、80 mg/kg)可有效降低术后粘连评分(P<0.05或P<0.01)。组织病理学切片结果显示SAB中、高剂量组能够减少粘连、血管化程度以及炎症细胞的浸润。ELISA结果显示SAB中、高剂量组可明显降低粘连大鼠血清TGF-β1和炎症因子IL-6、TNF-α的表达量(P<0.05或P<0.01)。qPCR和ELISA结果表明中、高剂量组能够逆转大鼠粘连组织MMP-9 mRNA和蛋白表达量的降低、TIMP-1 mRNA和蛋白表达量升高趋势,恢复MMP-9和TIMP-1水平的平衡(P<0.05或P<0.01)。结论SAB能降低大鼠术后腹膜粘连程度,其机制与降低粘连关键因子TGF-β1、减轻术后炎症反应和调节MMP-9与TIMP-1平衡有关。

美蓝预防和减少腹部手术后腹膜粘连的研究

探讨美蓝在临床上是否具有预防和减少腹部手术后腹膜粘连的作用及可能的机制。方法 :32例急性弥漫性腹膜炎及粘连性肠梗阻手术病人被随机分为两组 :美蓝组及对照组。观察其术后恢复情况及血清肿瘤坏死因子α(TNFα)水平、丙二醛 (MDA)含量及血红细胞超氧化物歧化酶 (SOD)活力的变化。结果 :美蓝组病人术后恢复优于对照组 ,术后血清MDA含量升高较对照组显著降低 ,血红细胞SOD活力的下降不如对照组 ,血清TNF水平明显低于对照组。结论 :美蓝可以预防和减少腹部手术后腹膜粘连 ,其作用的机制可能与美蓝抑制氧自由基的产生 ,降低TNFα水平 ,使腹膜损伤减轻有关。

术后肠粘连气腹造影的螺旋CT影像特征及其临床价值

目的:探讨成人术后肠粘连(postoperative peritoneal adhesion,POPA)气腹造影的螺旋CT影像(pneumoperitoneum helico-CT imaging,PHCT)特征及其临床价值。方法:术后慢性腹痛或有机械性肠梗阻反复发作的疑为术后肠粘连患者32例,采用腹腔穿刺置管注气造影后CT扫描,同时完成腹腔镜手术。对照手术所见对气腹造影影像特征进行解析判读,判定PHCT的临床应用价值。结果:2例(2/32,6.25%)患者表现为正常气腹腹腔CT图像,腹壁圆膨,腹内脏器呈平面铺展,其间为穹窿状的气腹空间,腹腔镜检查未发现粘连及其他病变。30例(30/32,93.75%)患者表现为局限性的腹壁粘连的影像特征,腹腔内脏器局部隆起,跨越气腹空间与腹壁贴附。粘连的脏器小肠、网膜最多见,另有肝脏、胃壁、横结肠和子宫。同时完成腹腔镜腹内粘连松解术,粘连的脏器组成、分布和形态的镜检结果与气腹造影影像相符。结论:PHCT检查安全、简便易行,对腹壁粘连可达到镜像显示的效果,能较全面地揭示腹部术后腹壁粘连的概况和特征。PHCT可作为腹腔镜检的替代手段,成为POPA临床诊断的基本方法,对手术的实施有指导性作用。

善得定对预防大鼠腹部手术后肠粘连的研究

目的 评价腹腔注射善得定对大鼠腹部手术后肠粘连的预防作用。方法 将 5 0只SD大鼠随机分为 5组 :Ⅰ组 ,对照组 ;Ⅱ组 ,腹腔内注射善得定 2 0 μg kg ;Ⅲ组 ,腹腔内注射善得定 40 μg kg ;Ⅳ组 ,腹腔内注射善得定 6 0 μg kg ;Ⅴ组 ,腹腔内注射透明质酸钠。各组动物均于术后 14d处死 ,肉眼评价粘连程度 ,并取粘连的肠段测羟脯氨酸 (OHP)。结果 Ⅱ ,Ⅲ ,Ⅳ ,Ⅴ组之粘连程度明显低于Ⅰ组 (P <0 .0 5 ) ;Ⅱ ,Ⅲ ,Ⅳ组粘连肠段的OHP明显低于Ⅰ组和Ⅴ组(P <0 .0 5 ) ;Ⅱ ,Ⅲ ,Ⅳ组间粘连程度及粘连肠段的OHP无明显差异 (P >0 .0 5 )。

腹腔粘连大鼠血清、腹腔灌洗液中IL-6、IL-8及TNF-α的变化

目的 探讨腹腔粘连大鼠血清、腹腔灌洗液中白介素 - 6 (IL- 6 )、白介素 - 8(IL- 8)、肿瘤坏死因子 α(TNF-α)的变化。方法 通过造成腹壁和盲肠浆膜的均一缺损制成大鼠腹腔粘连模型。术后 1、 3、 5、 7d取外周血和腹腔灌洗液测定 IL- 6、 IL- 8和 TNF- α含量。结果 与假手术组和正常对照组相比 ,模型组大鼠术后血清及腹腔灌洗液 IL- 6、IL- 8和 TNF- α升高 (P<0 .0 5或 P<0 .0 1)。

转化生长因子-β多克隆抗体预防腹腔粘连的实验研究

目的 利用转化生长因子 - β(TGF β)多克隆抗体 (多抗 )阻断TGF β生物学作用 ,观察TGF β多抗预防腹腔粘连的效果。 方法 建立大鼠术后肠粘连模型 ,分别腹腔注射生理盐水 (对照组 )、透明质酸钠 (透明质酸钠组 )和不同剂量的TGF β多抗 (抗TGF β组 ) ,术后 2 1d进行粘连评分 ,其中 30只大鼠分别于术后 3 ,1 0d处死 ,取粘连部位组织 ,用免疫组化法 ,测定TGF β的表达。 结果 术后 2 1d粘连评分 :抗TGF β组为 (2 .4± 0 .99) ,显著低于对照组 (6 .0± 1 .2 5)和透明质酸钠组 (3 .4±1 .0 3) ;在不同TGF β多抗浓度中 50 μg组较经济有效 ;对照组和透明质酸钠组TGF β的表达有时间依从性。术后 3d达高峰 ,这种表达可被TGF β多抗抑制。 结论 TGF β多抗在动物模型上可预防腹腔粘连的发生 ,其机制在于抑制了TGF

乌司他丁预防小鼠术后腹腔粘连实验研究(英文)

目的:研究乌司他丁预防小鼠术后腹腔粘连的能力。方法:以BALB/c小鼠为动物模型,经过一同一标准的腹膜损伤手术后,60只BALB/c小鼠随机分成两组:乌司他丁治疗组,生理盐水对照组,分别在关腹前腹腔内灌注乌司他丁及生理盐水。术后20d将小鼠处死,观察腹腔内粘连的情况,通过对粘连的程度、位置以及粘连类型的综合评价得出粘连分数。结果:乌司他丁治疗组的平均粘连分数(1.28±0.31)明显低于对照组(2.33±0.47),2-3级粘连发生率(23.3％)比对照组(76.7％)亦有明显减低(P<0.01)。无1例小鼠出现腹壁切口疝。结论:乌司他丁能够预防术后腹腔粘连形成,且对伤口愈合无明显影响。

川芎嗪纳米制剂抗大鼠术后腹腔粘连实验研究

目的探讨川芎嗪纳米制剂抗大鼠术后腹腔粘连的作用。方法将大鼠随机分组,共8组。术后观察大鼠一般情况,各组于术后1周和2周取8只观察粘连情况,采用Phillips评分法对腹腔粘连进行分级。结果各组分级评分与模型组比较,1周组与2周组中的川芎嗪纳米中、高剂量组具有较明显的抗术后粘连作用(P<0.05,P<0.01)。且以川芎嗪纳米组降低粘连发生率的作用尤为显著。结论川芎嗪纳米制剂具有较好的抗术后腹腔粘连的作用。

羧甲基纤维素钠在预防术后腹膜粘连中的作用

目的 :探讨羧甲基纤维素钠 ( SCMC)对术后腹膜粘连的预防作用。方法 :将 30只 Wistar大鼠随机分 A、B、C组 ,制作肠粘连模型 ,取 A组为对照组 ,B、C组在腹腔内损伤部位分别滴入透明质酸钠及 SCMC。术后 1 4d处死动物 ,观察各组腹膜粘连情况。结果 :A组粘连广泛、致密 ,C组轻微粘连 ,B组介于二者之间。结论