Phosphatidylcholine prevents postoperative peritoneal adhesions: an experimental study in the rat

Phosphatidylcholine (PC) is the main constituent of the surface-active material coating peritoneal mesothelium. It may prevent postoperative adhesion formation through production of a lubricant film on mesothelial defects. We therefore examined the effect of its soluble form on surgically induced intraabdominal adhesions in rats. The adhesions were induced at laparotomy by any of four different operative models. PC was administered intraperitoneally (20 mg/rat) or intravenously (20 mg/rat or 50 mg/rat) at the end of the operation and on the second and third postoperative day. It was found that the degree of postoperative adhesion formation was significantly reduced by the intraperitoneal injection of PC in all 4 models. In contrast, no effect was achieved by the intravenous injection of PC, not even at a very high dose level. Our results suggest that soluble PC administered intraperitoneally might be a potent adjunct in postoperative adhesion prevention.     

Efficacy of simvastatin in reducing postoperative adhesions after thyroidectomy: an experimental study

Background: We aimed to investigate whether simvastatin had any impact on the prevention of adhesion formation after thyroidectomy in a rat model.

Methods: This study was performed in 66 Wistar albino rats randomized into three experimental groups. A right hemithyroidectomy was carried out in all the rats. Simvastatin was administered locally at a dose of 0.5?mg/kg and 0.8?mg/kg. Control rats received a saline solution only. Changes during the 1st week, 1st month and 3rd month were evaluated. Efficacy of the treatment was assessed by using a scoring system.

Results: The severity of adhesions in low-dose simvastatin group was significantly less than the control and high-dose groups during the 1st and 3rd month (p?p?p?Conclusions: We investigated the influence of simvastatin application on post-thyroidectomy adhesion formation in rats. Whether adhesions, causing technical difficulties during neck redo surgery, can be reduced by the use of simvastatin in human, needs to be studied.     

Factors influencing the incidence of postoperative abdominal adhesions: an experimental study

Adult male Wistar rats were anesthetized with intraperitoneal sodium pentobarbitone, and laparotomies were performed to determine the role of common surgical practices in the etiology of intestinal adhesions. Rats were divided into 4 groups (Group 1, control; Group 2, small intestine delivered from the abdomen and placed on the skin without protection; Group 3, small intestine kept moist by covering with saline-soaked gauze; and Group 4, small intestine placed in plastic bag). At the end of 1 hour, all intestine were replaced in the peritoneal cavity, and rats were sacrificed 1 week later and examined for peritoneal adhesion formaiton. In general, the incidence of fibrinous adhesions was increased by removing the intestines from the peritoneal cavity. Groups 3 and 4 showed no lessening of adhesion formation with their various treatments. Incidence of plastic adhesions in laparotomy wounds closed without suturing was lower than when sutures were used. No difference was noted among types of suture material. The phenomenon of suture-induced adhestions seems a result of a reduction of fibrinolysin activity of serosa cells at the site, and the presence of the suture material allows the adhesion a harbor to establish itself in.     

Silicon prevents post laminectomy epidural root adhesions an experimental study in rats

Summary An experimental study was designed to test the efficacy of a silicon barrier around a nerve root in order to prevent post operative epidural root scar adhesions. In 32 Sprague-Dawely rats a lumbar nerve root was microsurgically exposed bilaterally. In 16 animals a silicon tube, prepared with a longitudinal cut along half of its wall, was placed around one nerve root, while the contralateral side served as control. In another group of 12 animals, an autologous subcutaneous fat graft was placed on the exposed root. A group of 4 animals served as the control group which had not been operated upon.No post operative neurological deficit was observed in any of the animals. All animals were sacrificed 60 days after the operation and a block of tissue including the nerve roots were resected bilaterally without removal of the silicon or fat graft. Longitudinal and transverse cuts of the roots were stained with Haematoxilin and Eosin and with Masson's trichrome collagen stain.The roots in the unoperated control group were clean of any scar tissue. In 13 out of 16 animals, silicon prevented scar formation around the root as opposed to scar adhesions around control root on the contralateral side and as compared to unoperated roots. In the silicon group, adhesions penetrated only through the longitudinal narrow cut edge of the tube. Fat did not prevent adhesions in 11 out of 12 animals.We conclude that a silicon barrier is an effective method preventing post operative epidural root scarring in rats.     

Preventing intraperitoneal adhesions with atorvastatin and sodium hyaluronate/carboxymethylcellulose: a comparative study in rats

Objectives

The aim of this study was to compare the effectiveness of atorvastatin with the sodium hyaluronate/carboxymethylcellulose (HA/CMC, Seprafilm; Genzyme; Genzyme Biosurgery Corporation, Cambridge, MA) in preventing postoperative intraperitoneal adhesion formation in rats.

Methods

Sixty Wistar rats underwent a laparotomy, and adhesions A were induced by cecal abrasion. The animals were divided into 4 groups: group 1, control A; group 2, (A + atorvastatin); group 3, (A + HA/CMC), and group 4, (A + atorvastatin + HA/CMC). The atorvastatin (groups 2 and 4) and HA/CMC (groups 3 and 4) were administered intraperitoneally before the abdominal wall was closed. After 14 days, adhesions were classified by 2 independent surgeons.

Results

The adhesion scores (mean ± standard deviation) for groups 1, 2, 3, and 4 were 2.93 ± .59, 1.85 ± 1.07, 1.80 ± .86, and 1.93 ± .70, respectively. The differences in adhesion scores among all 3 preventive groups (groups 2, 3, and 4) were statistically significant when compared with the control group (P = .005, P = .002, and P = .009, respectively).

Conclusions

These data suggest that atorvastatin, administered intraperitoneally, is as effective as HA/CMC without an expectable additive effect in preventing postoperative adhesions in rats.     

Effect of postoperative irradiation on free skin flaps: an experimental study in rats.

The modern treatment of musculoskeletal malignant tumours often requires different combinations of surgery, chemotherapy, and radiotherapy. Although combination treatments have allowed reconstruction of more complex defects, the risk of complications also rises. In clinical series the complication rate is influenced by the characteristics of the defect and the quality of the radiation used. The flap survival is high, but the overall complication rate is more than 25%. In this study we looked at the healing of microvascular free skin flaps exposed to postoperative irradiation in a rat model. Epigastric microvascular free skin flap were exposed to a single dose of 20 Gy radiation one week postoperatively (n = 8). A comparison was made with free epigastric skin flaps without postoperative radiation (n = 8). The healing was assessed histologically at four weeks and by measuring the tensile strength of the wound. Biochemical total nitrogen and hydroxyproline contents were also measured. Results showed that histologically the interfaces healed similarly with only minimal histomorphological changes. Neither the mechanical strength of the healing interface nor the biochemical markers altered significantly. Postoperative irradiation with a single dose of 20 Gy does not affect the survival of free skin flaps in rats. In the future the model described could be used to study the effects of combination therapy of surgery, radiotherapy, and chemotherapy more closely to find the optimal control of malignancies with limited damage to treated tissue.     

术中保温对老龄大鼠术后认知功能影响的实验研究

目的探讨术中保温护理对老龄大鼠术后认知功能障碍的影响。方法将30只18月龄雄性SD大鼠随机分为对照组、未保温组和保温组各10只。对照组未予以手术干预;未保温组手术过程中置于室温环境,未作保温处理;保温组手术过程中予以保温毯保温。结果与对照组比较,未保温组术中体温及血压显著降低,术后第7天Toll样受体4、髓样分化因子88和核转录因子κB P65表达水平显著提高;且术后第14天NeuN免疫荧光染色检测海马CA1区神经元数量减少,Morris水迷宫实验平台跨越次数、目标象限路径百分比、目标象限时间百分比显著降低(均P0.05)。与未保温组比较,保温组术后第7天Toll样受体4、髓样分化因子88和核转录因子κB P65表达上调程度降低,术后第14天海马CA1区神经元丢失数量减少,Morris水迷宫实验学习和记忆指标改善(均P0.05)。结论术中保温通过减轻老龄大鼠脑内免疫应激反应,改善术后认知功能障碍。     

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50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20μg/kg;Ⅲ组,腹腔内注射善得定40μg/kg,腹腔内注射得定60μg/kg;V组,腹腔内注射透明质酸钠。各组动物均于定40μg/kg;Ⅳ组,腹腔内注射善得定60μg/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＜0．05）;Ⅱ,Ⅲ,Ⅳ组粘连肠段的OHP明显低于I组和V组（P＜0．05）;Ⅱ,Ⅲ,Ⅳ组间粘连程度及粘连肠段的OHP无明显差异（P＞0．05）。结论 腹腔注射善得定对预防腹部手术后肠粘连有一定作用。     

应用己酮可可碱及聚烯酮碘预防术后肠粘连的实验研究

为观察己酮可可碱及聚烯酮碘预防术后肠粘连作用，作者采用８０只ＳＤ鼠制成肠粘连模型并分成四组：即对照组，聚烯酮碘组，己酮可可碱组和两药合用组。每组含动物２０只。结果显示各组粘连程度不同，从重到轻依次为对照组，聚烯酮碘组，己酮可可碱组和两药合用组。说明聚烯酮碘与己酮可可碱有预防术后肠粘连作用，两药合用可产生协同作用。     

奥曲肽预防术后腹腔粘连的实验研究

目的:评估奥曲肽在腹腔术后粘连中的作用.方法:选用120只Wistar大鼠,在同一标准下刮伤其盲肠浆膜,制成损伤性腹腔粘连模型.将动物随机分成6组.1组为对照组,于首次剖腹术后给予生理盐水作为安慰剂0.5ml/12h皮下注射.2、3组分别给予奥曲肽0.5ml 2.5μg/(kg·12h)和氢化可的松2mg/(kg·12h)皮下注射,应用2周;a、b、c组不给予任何干预,而于2周后,实施粘连松解术,术后同1、2、3组方法分别给予生理盐水、奥曲肽和氢化可的松皮下注射,应用2周.1、2、3组和a、b、c组分别于首次剖腹术和粘连松解术后2周观察腹腔粘连程度.结果:同对照组相比,奥曲肽无论在首次开腹术后还是在粘连松解术后均能显著减轻腹腔粘连(P＜0.01).而氢化可的松只在首次术后具有预防腹膜粘连的作用.结论:奥曲肽具有预防腹腔粘连形成的作用.     

Intraperitoneal adhesions after open or laparoscopic abdominal procedure: an experimental study in the rat

Abstract Background: Adhesion formation is common after abdominal surgery. The incidence and severity of adhesion formation following open or laparoscopic surgery remain controversial. The role of CO(2) pneumoperitoneum is also widely discussed. This study aimed to compare adhesion formation following peritoneal injury by electrocoagulation performed through open or laparoscopic procedures in a rat model. Materials and Methods: Sixty male rats were randomized to undergo a 1.5-cm peritoneal injury with unipolar cautery under general anesthesia: open surgery (Group A, n=20), laparoscopic surgery with CO(2) pneumoperitoneum (Group B, n=20), and laparoscopic surgery with air pneumoperitoneum (Group C, n=20). Duration of the procedures was fixed at 90 minutes in all groups, and pneumoperitoneum pressure was kept at 10?mm Hg. Ten days later, the animals underwent a secondary laparotomy to score peritoneal adhesions using qualitative and quantitative parameters. Results: Forty-five rats developed at least one adhesion: 95% in Group A, 83% in Group B, and 55% in Group C (P<.01; Group C versus Group A, P<.01). According to number, thickness, tenacity, vascularization, extent, type, and grading according to the Zühkle classification, no significant difference was observed between Groups A and B. The distribution of adhesions after open surgery was significantly different than after laparoscopic surgery (P<.001). It is interesting that Group C rats developed significantly fewer adhesions at the traumatized site, and their adhesions had less severe qualitative scores compared with those after open surgery (P<.01). Conclusions: In this animal model, CO(2) laparoscopic surgery did not decrease the formation of postoperative adhesion, compared with open surgery. The difference with the animals operated on with air pneumoperitoneum emphasizes the role of CO(2) in peritoneal injury leading to adhesion formation.     

Effects of hyaluronic acid on postoperative adhesion of tendo calcaneus surgery: an experimental study in rats.

Adhesions are a significant problem after tendon surgery. The effects of hyaluronic acid on adhesion formation of the tendo calcaneus were investigated in this study. Twenty Wistar rats were utilized. Both tendo calcanei were incised transversely, and then repaired. Hyaluronic acid (0.2 cc) was injected into peritendinous tissue on the right side, while the same amount of normal saline was injected to the left side as a control. The animals were sacrificed 40days after the experiment. Both the right and left tendon adhesions were evaluated both macroscopically and microscopically for the presence of adhesions (grading scale 0-4). Throughout the experimental period, there was no difference in range of motion of the ankle between the two groups. Macroscopically, there were fewer adhesions in the experimental group (mean 0.6 +/- 0.8) compared to the controls (mean 1.1 +/- 0.2). This difference was not statistically significant (p = .096). Histopathologically, these parameters were similar in both the experimental (mean 1.15 +/- 0.98) and the control groups (mean 1.9 +/- 1.25). This difference was significant (p = .043). Hyaluronic acid may be effective for prevention of adhesions in the tendo calcaneus though this effect could not be demonstrated experimentally.     

Early and late postoperative inflammatory and collagen deposition responses in three different meshes: an experimental study in rats

Purpose

Although meshes reduce abdominal hernia recurrence, they increase the risk of inflammatory complications. This study aimed to compare the early and late postoperative inflammation and collagen deposition responses induced by three meshes.

Methods

Rats were allocated into three groups. In group I, a polypropylene (PP) mesh was implanted in the abdominal wall. In groups II and III, PP + polyglactin (PP + PG) and PP + titanium (PP + TI) meshes were employed, respectively. On the seventh (7th) postoperative day, collagen deposition and inflammation were evaluated, and immunohistochemistry was performed on abdominal wall biopsies. These data were compared with those obtained on the fortieth (40th) postoperative day in a previous study.

Results

The early inflammatory responses were the same in all groups. With time, it decreased in group I (p = 0.047) and increased in group II (p = 0.003). Group I exhibited early elevated VEGF (p < 0.001), COX2 (p < 0.001), and collagen (p = 0.023) levels, and group II exhibited the most severe inflammatory tissue response. On the 40th postoperative day, the VEGF (p < 0.001) and collagen (p < 0.005) were reduced as compared with the 7th postoperative day in all groups.

Conclusions

Belatedly, the inflammatory reaction decreased in PP mesh group and increased in PP + PG mesh group. The PP mesh induced early great elevations in VEGF, COX2 and collagen levels, whereas the PP + PG mesh caused severe tissue inflammation with small elevation in these levels. PP + TI mesh induced inflammatory response levels between the others. In conclusion, the inflammatory response depends on the mesh density and also the mesh material with clinical implications.