Prevention of postoperative pericardial adhesions. An animal study

Following heart operations, adhesions uniformly form between the epicardium and surrounding structures such as the pericardium, mediastinal fat, pleura, and sternum. These adhesions make reoperations both difficult and hazardous. Three groups of 15 dogs each were studied to assess the effectiveness of pharmacologic manipulation in reducing the adhesions. In the control group, adhesions were created by allowing epicardial/pericardial surfaces to dry, and then adding cotton fibers and blood before closing the pericardium. In the methylprednisolone group, 500 mg of methylprednisolone was given intravenously at the time of operation, followed by 0.3 mg/kg orally three times a day for one week. In the ibuprofen group, 12.5 mg/kg of ibuprofen was given intravenously at operation and then orally three times in one day, followed by 5 mg/kg orally three times a day for six days. Dogs were killed at three to four weeks and the adhesions between pericardium and epicardium were graded. In the control group, none were adhesion-free and none had filmy adhesions; three dogs had dense patchy adhesions and 12 had dense diffuse adhesions. In the methylprednisolone group, 14 dogs had no adhesions; one had filmy adhesions; and none had dense patchy or dense diffuse adhesions. In the ibuprofen group, none were adhesion-free; one dog had filmy adhesions; four had dense patchy adhesions; and ten had dense diffuse adhesions. The near-total elimination of pericardial/epicardial adhesions utilizing methylprednisolone, if also achievable in humans, would markedly reduce the difficulty and increase the safety of cardiac reoperations.     

改性壳聚糖防粘连膜防止心肌梗死模型兔心脏与周围组织粘连

目的 观察改性壳聚糖防粘连膜对心肌梗死兔心脏与周围组织粘连程度的影响.方法 25只日本长耳白兔,开胸结扎冠状动脉制备心肌梗死模型,随机分为对照组(A组)和改性壳聚糖防粘连膜组(B组),A组正常关胸,B组关胸前在心脏和胸壁间置入改性壳聚糖防粘连膜.每组造模型成功各11只.术后3个月A组存活8只、B组存活9只.分别行在体磁共振电影和二次开胸,分级评价粘连程度.采用Wilcoxon秩和检验.结果 磁共振电影评价粘连程度,A组轻度粘连、中度粘连、重度粘连分别为2只、2只、4只;B组分别为7只、2只、0只.差异有统计学意义(P<0.05).开胸评价粘连程度,A组无粘连、轻度粘连、中度粘连、重度粘连分别为1、1、2、4只;B组分别为3、4、2、0只.差异有统计学意义(P<0.05).结论 改性壳聚糖防粘连膜可以减轻心肌梗死模型兔心脏与周围组织粘连.     

改性壳聚糖防粘连膜防止心肌梗死模型兔心脏与周围组织粘连

目的 观察改性壳聚糖防粘连膜对心肌梗死兔心脏与周围组织粘连程度的影响.方法 25只日本长耳白兔,开胸结扎冠状动脉制备心肌梗死模型,随机分为对照组(A组)和改性壳聚糖防粘连膜组(B组),A组正常关胸,B组关胸前在心脏和胸壁间置入改性壳聚糖防粘连膜.每组造模型成功各11只.术后3个月A组存活8只、B组存活9只.分别行在体磁共振电影和二次开胸,分级评价粘连程度.采用Wilcoxon秩和检验.结果 磁共振电影评价粘连程度,A组轻度粘连、中度粘连、重度粘连分别为2只、2只、4只;B组分别为7只、2只、0只.差异有统计学意义(P<0.05).开胸评价粘连程度,A组无粘连、轻度粘连、中度粘连、重度粘连分别为1、1、2、4只;B组分别为3、4、2、0只.差异有统计学意义(P<0.05).结论 改性壳聚糖防粘连膜可以减轻心肌梗死模型兔心脏与周围组织粘连.     

改性壳聚糖防粘连膜防止心肌梗死模型兔心脏与周围组织粘连

目的 观察改性壳聚糖防粘连膜对心肌梗死兔心脏与周围组织粘连程度的影响.方法 25只日本长耳白兔,开胸结扎冠状动脉制备心肌梗死模型,随机分为对照组(A组)和改性壳聚糖防粘连膜组(B组),A组正常关胸,B组关胸前在心脏和胸壁间置入改性壳聚糖防粘连膜.每组造模型成功各11只.术后3个月A组存活8只、B组存活9只.分别行在体磁共振电影和二次开胸,分级评价粘连程度.采用Wilcoxon秩和检验.结果 磁共振电影评价粘连程度,A组轻度粘连、中度粘连、重度粘连分别为2只、2只、4只;B组分别为7只、2只、0只.差异有统计学意义(P<0.05).开胸评价粘连程度,A组无粘连、轻度粘连、中度粘连、重度粘连分别为1、1、2、4只;B组分别为3、4、2、0只.差异有统计学意义(P<0.05).结论 改性壳聚糖防粘连膜可以减轻心肌梗死模型兔心脏与周围组织粘连.     

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.     

术后肠粘连与肿瘤生长转移的相关性及PDLLA干预的实验研究

目的研究腹部手术后肠粘连和肿瘤生长、转移间的相关性,并探讨可降解聚-DL-乳酸可吸收医用膜（PDLLA）的治疗效果.方法雄性Wistar大鼠60只分为肿瘤移植组（A组）和非肿瘤移植组（B组）.A、B两组又分为肠粘连模型、PDLLA治疗和假手术组,分别行手术,术后4周用半定量方法对肠粘连形成和肿瘤生长、转移情况进行评分.结果术后4周肿瘤移植组各亚组的肿瘤生长、转移和肠粘连评分均大于非肿瘤移植组（P＜0.05）,肠粘连模型组的肿瘤生长、转移和肠粘连评分均高于PDLLA干预组（P＜0.05）.术后肠粘连的形成及严重程度与肿瘤生长、转移呈正相关（P＜0.05）;PDLLA干预和术后肠粘连、肿瘤生长和转移评分呈负相关（P＜0.05）.结论PDLLA在减少术后肠粘连形成的同时有可能同时减少与肠粘连相关的肿瘤生长和转移.     

术后腹腔感染病人的预后估计(附193例分析)

以上海中山医院近１０年资料较完整的１９３例术后腹腔感染者为研究对象，对３１项常用临床观察指标，用Ｌｏｇｉｓｔｉｃ多因素回归分析方法筛选出消化道出血、年龄、尿素氮、动脉血氧分压和血培养５项为危险因素，与感染后死亡有关。相应的回归模型预测感染后死亡的敏感性、特异性和准确性分别为８５．７％、８２．７％和８５％。     

Foreign material in postoperative adhesions.

OBJECTIVE: The authors determined the prevalence of foreign body granulomas in intra-abdominal adhesions in patients with a history of abdominal surgery. PATIENTS AND METHODS: In a cross-sectional, multicenter, multinational study, adult patients with a history of one or more previous abdominal operations and scheduled for laparotomy between 1991 and 1993 were examined during surgery. Patients in whom adhesions were present were selected for study. Quantity, distribution, and quality of adhesions were scored, and adhesion samples were taken for histologic examination. RESULTS: In 448 studied patients, the adhesions were most frequently attached to the omentum (68%) and the small bowel (67%). The amount of adhesions was significantly smaller in patients with a history of only one minor operation or one major operation, compared with those with multiple laparotomies (p < 0.001). Significantly more adhesions were found in patients with a history of adhesions at previous laparotomy (p < 0.001), with presence of abdominal abscess, hematoma, and intestinal leakage as complications after former surgery (p = 0.01, p = 0.002, and p < 0.001, respectively), and with a history of an unoperated inflammatory process (p = 0.04). Granulomas were found in 26% of all patients. Suture granulomas were found in 25% of the patients. Starch granulomas were present in 5% of the operated patients whose surgeons wore starch-containing gloves. When suture granulomas were present, the median interval between the present and the most recent previous laparotomy was 13 months. When suture granulomas were absent, this interval was significantly longer--i.e., 30 months (p = 0.002). The percentage of patients with suture granulomas decreased gradually from 37% if the previous laparotomy had occurred up to 6 months before the present operation, to 18% if the previous laparotomy had occurred more than 2 years ago (p < 0.001). CONCLUSIONS: The number of adhesions found at laparotomy was significantly larger in patients with a history of multiple laparotomies, unoperated intra-abdominal inflammatory disease, and previous postoperative intra-abdominal complications, and when adhesions were already present at previous laparotomy. In recent adhesions, suture granulomas occurred in a large percentage. This suggests that the intra-abdominal presence of foreign material is an important cause of adhesion formation. Therefore intra-abdominal contamination with foreign material should be minimized.     

The role of simvastatin on postoperative peritoneal adhesion formation in an animal model

AIM: The aim of this study is to show the effect of simvastatin on intra-abdominal adhesion formation. METHOD: Adhesion formation was achieved by scratching the cecum and anterior abdominal wall following median laparotomy. Three different groups of 10 rats each were formed. In group I, 0.57 mg/kg/day simvastatin was injected intraperitoneally right after the operation and for 5 days thereafter. In group II, an equal dose of simvastatin to that used in group I was given via gavage. A physiological saline solution was given to group III for the same period of time. On the 6th and 14th day, blood samples were taken and peritoneal lavage was performed to measure the tissue-type plasminogen activator (t-PA) activity. Adhesions were graded via re-laparotomies on the 14th day after the first operation. RESULTS: The adhesion scores were 1.40 +/- 0.22, 1.50 +/- 0.26, and 2.90 +/- 0.34 in groups I, II, and III, respectively (p = 0.007), and the score was higher in group III than in the other groups (p = 0.005, p = 0.011). CONCLUSION: Intraperitoneal simvastatin application decreases adhesion formation by increasing the t-PA level in abdominal surgery.     

An animal study of different treatments to prevent postoperative pelvic adhesions

A study was designed to test various high-molecular-weight solutions in the prevention of postoperative intraabdominal adhesions. The bicornuate rat uterus was used as the surgical model, and 80 mature white female rats underwent surgical injury of the right uterine horn. The rats were randomly divided into 5 groups: groups A, B, and C received 5 ml intraperitoneally of chondroitin sulfate, sodium carboxymethylcellulose, and 32% dextran 70, respectively; group D was treated with microsurgical repair; and group E, the control, received no therapy. The animals were killed postoperatively, and the adhesions were scored. Significantly better results in adhesion prevention were demonstrated in the sodium carboxymethylcellulose group vs. the other groups, except in group A where the difference was not significant.     

An experimental study evaluating the effect of Mitomycin C on the prevention of postoperative intraabdominal adhesions

BACKGROUND: Fibroblast proliferation is one of the well-known mechanisms for postoperative intraabdominal adhesion formation. Inhibition of fibroblast proliferation is an attractive field of investigation in the prevention of adhesions. Mitomycin C (MMC) is a cytotoxic agent that alkylates and crosslinks DNA and also inhibits fibroblast proliferation up to a few weeks. We aimed to determine the effect of MMC on the prevention of adhesions. MATERIALS AND METHODS: Generation of adhesions in rats by brushing a 1-cm(2) area of the cecum and the peritoneum on the right side of the abdominal wall was followed by intraperitoneal administration of saline, 1 mg/kg MMC, and 0.5 mg/kg MMC in saline. After 45 days, formation of adhesions was graded. RESULTS: The average adhesion scores of the control, and MMC (1 mg/kg), MMC (0.5 mg/kg) groups were 3.2 +/- 0.7, 0.8 +/- 0.6, and 0.7 +/- 0.8, respectively. Adhesion scores of the two MMC-treated groups were significantly lower than that of the control group (P < 0.001). There was no difference between the two MMC groups (P > 0.05). No side effect of MMC was observed. CONCLUSION: MMC was found to be very effective in the prevention of postoperative intraabdominal adhesions.     

Sepramesh and postoperative peritoneal adhesions in a rat model

Purpose: The present study aimed to investigate the safety and the anti-postoperative peritoneal adhesion (PPA) characteristics of Sepramesh^® (Davol), a composite mesh made of polypropylene covered with Seprafilm, when intraperitoneally placed in a rat model.

Methods: Twenty male rats were randomized into a control group and a Sepramesh group. They underwent a primary surgical procedure aiming to induce a peritoneal injury in order to induce PPAs. In the Sepramesh group, the burnt peritoneum was covered with a 2-cm diameter disc of Sepramesh prosthesis. The mesh was fixed to the parietal peritoneum with four 3-0 absorbable stitches. PPAs were assessed during a second laparotomy 10 days later using quantitative and qualitative scoring systems.

Results: There was no difference in terms of mean number of PPAs between both groups. All the rats from the control group developed PPAs. In the Sepramesh group, no adhesions were observed at the site of the injured peritoneum that had been covered with the Sepramesh prosthesis, but PPAs occurred at the extremities of the mesh, where there was close contact between polypropylene and viscera, or where the fixation sutures were placed. The severity and the type of adhesions were significantly higher in the control group.

Conclusions: This study demonstrated that for the Sepramesh prostheses, the Seprafilm layer might be effective in PPA prevention, but damage caused by the section and fixation of Sepramesh should be limited in order to limit PPAs.     

The effectiveness of various antibiotics in methyl methacrylate.

The effectiveness of different antibiotics mixed with Simplex P has been tested in vitro. A laboratory model was designed to simulate the constant immersion of bone cement in tissue fluid. Clindamycin, and to a lesser extent Cephalothin, were shown to be effective when used in this manner against Staphylococcus aureus and epidermidis. Effective inhibition of Gram-negative organisms could not be demonstrated with any of the antibiotics tested. The addition of up to 3 grams of antibiotic powder per unit of 40 grams of Simplex P did not appear to alter the expansive properties of the cement. Such release of antibiotics as did occur was thought to be related to the slow absorption of water by the slightly porous methyl methacrylate.     

Glucan enhances survival in an intraabdominal infection model

The immunomodulator glucan exists in two forms, particulate (glucan-P) and soluble (glucan-F). Both preparations of glucan, either alone or in combination with antibiotic therapy, were evaluated for their ability to augment survival in rats following cecal ligation and puncture (CL/P). Adult male rats were infused once daily for 5 consecutive days with either glucan-P (10 mg/kg), glucan-F (10 mg/kg), or 5% (w/v) dextrose in water. Three days later all rats underwent CL/P. Postoperatively, the rats received (a) no therapy, (b) saline (1 ml subcutaneously every 12 hr) or (c) ampicillin (33 mg/kg subcutaneously every 12 hr) for 7 days. Without any associated pre-or postoperative treatment, CL/P was associated with an 85% 7-day mortality. Neither glucan preparation alone significantly altered this mortality. Administering ampicillin postoperatively decreased the mortality to 53% (P less than 0.001 vs untreated controls). When postoperative ampicillin therapy was combined with preoperative glucan treatment, the mortality was reduced even further (26% for glucan-P, 21% for glucan-F; P less than 0.02 vs ampicillin-treated controls). We conclude from these results that (i) neither glucan preparation alone effectively enhances survival following CL/P when using the doses and administration schedule employed herein, (ii) both glucan-P and glucan-F do act synergistically with antibiotics to enhance survival in this rat model of polymicrobial sepsis, and (iii) in this particular model, nontoxic glucan-F is as efficacious as glucan-P.     

The effectiveness of active head restraint in preventing whiplash.

BACKGROUND: Whiplash injury claims have increased for two decades and manual head restraints are often incorrectly adjusted. A Self-Aligning Head Restraint (SAHR) was designed to move upward and forward by occupant motion in a rear crash providing earlier neck support, even when the head restraint is positioned low. This study determines its field effectiveness. METHODS: Insurance records were analyzed for consecutive Saab rear crashes in Sweden over 18 months. The Saab 9000/900 had standard head restraints and Saab 9-5/9-3 had SAHR. A questionnaire was mailed to the occupants, insurance and medical records were reviewed, and phone interviews were conducted. RESULTS: SAHR reduced whiplash injury risks by 75 +/- 11% from an 18 +/- 5% incidence in 85 occupants with standard head restraints to 4 +/- 3% in 92 occupants with SAHR. No SAHR seat required repair or replacement after the crashes. CONCLUSION: SAHR is effective in reducing whiplash injury in rear crashes and is a passive public-health approach that works irrespective of manual head-restraint adjustment.