Effects of omentectomy on the peritoneal fibrinolytic system

PURPOSE: Decreased fibrinolytic activity in the serosal surfaces of peritoneal tissue appears to be a major factor in the development of peritoneal fibrous adhesions. The omentum reduces peritoneal adhesion by creating a mechanical barrier and producing fibrinolytic factors. This experimental study was designed to investigate the effects of omentectomy on the peritoneal fibrinolytic system. METHODS: Thirty animals were assigned randomly to a control group or an omentectomy group. On postoperative day 10, peritoneal and blood samples were collected and adhesions were graded qualitatively. We measured the concentrations of serum and peritoneal tissue plasminogen activator, peritoneal plasminogen activator inhibitor-1, tissue plasminogen activator/plasminogen activator inhibitor complex, and hydroxyproline. RESULTS: Adhesions were significantly increased after omentectomy. Omentectomy also resulted in a reduction of both serum and tissue "tissue plasminogen activator" levels. On the other hand, an increment in "plasminogen activator inhibitor-1" levels was observed after omentectomy. There were no differences in "tissue plasminogen activator/plasminogen activator inhibitor" complex or "hydroxyproline" levels. CONCLUSION: Omentectomy reduced peritoneal fibrinolytic activity significantly and the peritoneal plasminogen activator system showed corruption that did not resolve with the rest of the peritoneal system after omentectomy.     

化学改性壳聚糖膜预防不同类型腹膜粘连的实验研究

目的对比研究化学改性壳聚糖膜对四种不同原因所致的大鼠腹膜粘连的预防作用。方法将壳聚糖行化学改性,制成厚60μm的膜消毒后备用。SD大鼠200只,随机分成假手术对照组（A组）、创伤致粘连组（B组）、滑石粉致粘连组（C组）、结扎血管致粘连组（D组）及感染致粘连组（E组）。各组分别用相应的方法来处理大鼠蚓突盲端．再将每组大鼠分成对照组和实验组．对照组大鼠直接关腹,实验组用凝胶化改性壳聚糖膜覆盖蚓突盲端浆膜面．然后关腹。处理后2周和4周后打开腹腔,以Bhatia分级法评定蚓突盲端的粘连程度,并对盲端组织行羟脯胺酸（hydroxyproline,OHP）、组织型纤溶酶原激活剂tissue—type plasminogen activatior,t—PA）和纤溶酶原激活物抑制因子（plasminogen activator inhibitor,PAI）水平测定,对腹腔液行t—PA、PAI测定。结果①粘连程度和OHP水平：术后2周和4周,B、D、E组中实验组的粘连程度、OHP水平均分别显著低于对照组（P〈0．05）,而A、C组中的实验组和对照组间差异均无统计学意义（P〉0．05）;②t-PA、PAI水平：术后2周和4周,A组、C组和D组的蚓突组织和腹腔液t—PA、PAI水平．实验组和对照组间差异均无统计学意义（P〉0．05）;B组、E组中实验组t—PA水平均显著高于对照组（P〈0．05）,而PAI水平则显著低于对照组（P〈0．05）。结论化学改性壳聚糖膜时创伤、缺血及感染所致的腹膜粘连有明显的预防作用,而对滑石粉所致的腹膜粘连则作用不明显;对不同原因所致的腹膜粘连．可以用来准确衡量组织粘连程度的指标也不尽相同。     

凝胶化改性壳聚糖膜预防腹膜粘连的效果研究

目的对比研究凝胶化改性壳聚糖膜和透明质酸钠对腹膜粘连的预防作用。方法SD大鼠80只,随机分成4组：假手术对照组（A组）,生理盐水对照组（B组）,凝胶化改性壳聚糖膜组（C组）,透明质酸钠组（D组）。利用大鼠蚓突盲端制作创伤性腹膜粘连模型,然后每组分别用相应的方法处理创面,处理后第2周和第4周打开腹腔,以Bhada分级法评定蚓突盲端的粘连程度,并对盲端组织行羟脯胺酸（OHP）水平测定和病理组织学检查。结果术后第2周和第4周,C,D组的粘连程度均显著轻于B组（P=0．001～0．013）,OHP水平显著低于B组（P=0．037～P〈0．001）;C组和D组比较,粘连程度分级的差异两组间无显著性意义（P〉0．05）,但OHP含量C组显著低于D组（P=0．005,0．002）。病理学检查：A组所有大鼠蚓突组织无明显的病理改变,B组术后第2周时处理侧浆膜面有明显的炎症细胞浸润和纤维组织增生,术后第4周局部主要以纤维组织增生为主;相应的病理改变C,D组较B组明显减轻,C组的病理改变又明显轻于D组。结论凝胶化改性壳聚糖膜具有明显的抗腹膜粘连作用,且此作用较透明质酸钠具有优势。     

壳聚糖凝胶对大鼠腹膜粘连的预防作用

目的:探讨壳聚糖凝胶对三种不同原因所致的大鼠腹膜粘连的预防作用.方法:144只SD大鼠,随机分成创伤致粘连组(A组)、滑石粉致粘连组(B组)及结扎血管致粘连组(C组).各组分别用相应的致粘连方法来处理大鼠蚓突盲端,再将每组大鼠分成对照组和实验组,对照组大鼠直接关腹,实验组用壳聚糖凝胶均匀涂布于经处理的蚓突浆膜面,然后关腹.处理后2 w、4 w再次打开腹腔,肉眼评定蚓突盲端同其周围组织的粘连程度,并取蚓突盲端组织行病理组织学检查.结果:①粘连评定:术后2 w和4 w,A组和C组中实验组的粘连程度均分别显著低于对照组(P<0.05或P<0.01),而B组中的实验组和对照组间均无明显差异(P>0.05).②病理改变:A组处理侧浆膜面以纤维组织增生为主,而C组蚓突全层均有纤维组织增生,以浆膜层为重.B组处理侧浆膜面有大量异物巨细胞反应及肉芽肿形成,并伴有程度不同的纤维组织增生.结论:壳聚糖凝胶对创伤及缺血所致的腹膜粘连有明显的预防作用,而对异物所致的腹膜粘连作用则不明显.     

A possible role of thrombin-activatable fibrinolysis inhibitor in disturbances of fibrinolytic system in renal transplant recipients.

BACKGROUND: Cardiovascular disease (CVD) is a major cause of death in renal transplant recipients (RTR). Suppression of fibrinolysis plays a role in the progression of atherosclerosis. Accelerated progression of atherosclerosis and fibrinolytic system suppression has been observed in RTR. Despite many years of intensive research, the reason for impaired fibrinolysis in this patient population is not fully understood. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a recently discovered glycoprotein combining coagulation and fibrinolysis. This study was conducted to evaluate concentrations of TAFI, markers of thrombin generation, endothelial injury, and some standard laboratory parameters in RTR receiving triple immunosuppressive drug regimen. METHODS: The study was performed in 29 stable, non-diabetic kidney transplant recipients treated with cyclosporin A, azathioprine, and prednisone and in 18 age- and sex-matched healthy volunteers. Soluble thrombomodulin (sTM), prothrombin fragments F1+2 (F1+2), thrombin--antithrombin complexes (TAT), plasmin--antiplasmin complexes (PAP), and TAFI were measured with commercially available kits. RESULTS: The RTR group had significantly higher plasma levels of TAT, F1+2, sTM and TAFI than the healthy volunteers. There were no differences in PAP concentrations between the two groups. Plasma sTM correlated inversely with creatinine clearance, body mass index, haemoglobin, and albumin. Plasma TAT level was positively associated with total cholesterol. TAFI antigen influenced negatively PAP antigen concentration. CONCLUSIONS: On the basis of our research, we concluded that elevated circulating TAFI antigen might be a new link in the pathogenesis of impaired fibrinolysis in RTR, and thus atherosclerosis progression. In the patient group there is also evidence of endothelial injury, followed by secondary activation of the coagulation cascade. Hypercholesterolaemia in RTR is associated with enhanced thrombin activity.     

Preventive Effect of Ethyl Pyruvate on Postoperative Adhesion Formation Following Abdominal Surgery

Objective: Postoperative adhesions are among the major causes of morbidity and mortality following abdominal surgery. As an antioxidant and antiinflamatory agent, the potential effect of ethyl pyruvate on adhesion prevention has not been clearly studied. We aimed to investigate the possible anti-adhesive effect of ethyl pyruvate compared with an effective barrier membrane, Seprafilm, in a rat cecal abrasion model. Materials and Methods: Male Wistar albino rats separated into three adhesion model groups (n = 8, each) with applications of different agents during surgery: control (intraperitoneal normal saline), Seprafilm group (intraperitoneal Seprafilm), and Ethyl pyruvate group (40 mg/kg intraperitoneal ethyl pyruvate). Postoperative adhesion was graded both macroscopically and histopathologically. Malondialdehyde and nitric oxide levels were determined from tissue samples for assessment of oxidative stress. Results: Seprafilm and Ethyl pyruvate groups had lower adhesion scores (both macroscopic and microscopic) and decreased malondialdehyde and nitric oxide levels compared to the control group (p < 0.05 for all parameters). The results were comparable for both Seprafilm and Ethyl pyruvate groups for all parameters (p > 0.05). Conclusions: Intraperitoneal ethyl pyruvate application reduced the incidence and the extent of postoperative adhesions in rat cecal abrasion model. Ethyl pyruvate also had comparable overall efficacy for adhesion prevention as Seprafilm.     

Duplicated peritoneal catheter as a cause of shunt malfunction. Case report

A rare example of ventriculo-peritoneal shunt malfunction is presented. Radiological and operative findings demonstrated a selfduplication with upward migration of the peritoneal catheter.     

Fibrinolytic responses of human peritoneal fluid in laparoscopic cholecystectomy: a prospective clinical study

Background The reduction in peritoneal fibrinolysis is believed to be the pathogenetic mechanism of adhesion formation. The general conclusion based on previous clinical and experimental studies is that laparoscopic procedures produce less adhesion formation. The association between this beneficial effect of laparoscopic cholecystectomy and peritoneal fibrinolytic changes is not clear. Therefore, the authors aimed to compare the effects of open and laparoscopic cholecystectomy on peritoneal fibrinolysis. For this purpose, fibrinolytic parameters in peritoneal fluid were investigated 24 h after laparoscopic and open cholecystectomies. Methods In a prospective clinical study, peritoneal fluid was sampled via a drain 24 h after laparoscopic (n = 10) and open (n = 9) cholecystectomies. Activities and concentrations of tissue plasminogen activator (tPA), plasminogen activator inhibitor type 1 (PAI-1), and tPA/PAI-1 complex were determined by enzyme-linked immunosorbent assay (ELISA) kits. Results In peritoneal fluids, tPA and tPA/PAI-1 complex concentrations were higher in the open cholecystectomy group (p = 0.009 and p < 0.001, respectively), but tPA activity and PAI-1 concentrations did not differ between the groups (p = 0.514 and p = 0.716, respectively). Conclusions Fibrinolytic changes in peritoneal fluid have several similarities in open and laparoscopic cholecystectomies with regard to tPA activity and PAI-1 levels. However, higher tPA levels after the open procedure probably are secondary to more intense tissue handling leading to mesothelial release of tPA.     

Peritoneal fibrinolytic response to various aspects of laparoscopic surgery: a randomized trial

BACKGROUND: Peritoneal fibrinolysis is important in peritoneal wound healing processes and adhesion formation. The peritoneal fibrinolytic response to laparoscopy is merely unknown. In the present study we investigate the effect of short-term laparoscopy on the peritoneal fibrinolytic response and the influence of intra-abdominal pressure, light intensity and choice of dissection device on this response. METHODS: There were 50 patients scheduled for laparoscopic cholecystectomy randomized in five groups operated with various pressures, light intensities, and dissection devices. Peritoneal biopsies were taken at the beginning and the end of the procedure. Tissue concentrations of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type 1 (PAI-1), and the tPA-activity were measured using ELISA techniques. RESULTS: There were no differences in tPA antigen, tPA-activity, uPA antigen, or PAI-1 antigen concentrations in biopsies taken at the beginning compared to samples taken at the end of the operation. Different intra-abdominal pressures, light intensities and the choice dissection device did not affect any of the measured parameters. CONCLUSION: Short-term laparoscopy does not affect the peritoneal fibrinolytic activity. The used intra-abdominal pressure, light intensity and choice of dissection device do not affect peritoneal activity during short-term laparoscopy.     

The influence of different procedures of general anaesthesia on platelet function,coagulation and the fibrinolytic system

We investigated whether different procedures during general anaesthesia alter platelet activation in vivo and/ or activate coagulation and fibrinolysis. Forty-one healthy adult patients, scheduled for elective ophthalmic surgery under general anaesthesia, were studied with regard to changes of plasma beta-thromboglobulin (βG, index of platelet activation), thrombin-antithrombin Ill-complex (TAT, index of activation of coagulation) and d-dimer (index of fibrinolysis) during anaesthesia. The patients underwent either inhalation anaesthesia with enflurane and nitrous oxide or balanced anaesthesia with enflurane (0.5% end-tidal concentration) and alfentanil. Ten minutes after intubation the βTG level was significantly reduced compared to the preoperative value in both general anaesthesia groups. Balanced anaesthesia caused a moderate but significant increase of TAT values at 10 min after extubation. No significant change in d-dimer levels was seen. Presuming a minimal effect of the surgical procedure on the determined variables, we conclude that none of the anaesthetic procedures induces platelet activation and fibrinolysis. The clinical relevance of the moderate coagulation activation during balanced anaesthesia remains to be investigated.     

Clinical evaluation of the peritoneal equilibration test: a population-based study

A total of 143 Peritoneal Equilibration Tests (PETs) were performedin 104 CAPD patients over a period of 18 months. A normal range(95% confidence limits) was constructed from 100 tests (68 consecutivenew patients, 32 routine tests on problem-free patients) usinga 2-dimensional plot of solute transfer (D/P_creat) and ultrafiltrationvolume. These two parameters correlated inversely (r= –0.59,P<0.0001)allowing calculation of a regression line. In the short term(<3 months) D/P_creat was stable across a wide range of values(0.45–0.98) with good correlation between tests indicatingreproducibility (r =0.94, P<0.001). Repeated tests beyond3 months were variable, explaining changes in the clinical picture,and in the majority of cases shifts in D/P_creat and ultrafiltrationparallelled the regression line for the whole population. Sixof seven (85%) of patients with mechanical problems and 14 of15 (93%) with poor ultrafiltration had at least one abnormaltest, and these two problems could be distinguished in 90% ofcases by 2-dimensional plotting. In five with ultrafiltrationfailure, dialysate volumes were less than predicted by soluteclearance, and these patients failed continuous cycling peritonealdialysis (CCPD). In contrast, a good response to CCPD was predictedcorrectly in five patients with high solute clearance. In ninepatients with plasma creatinine >1250µmol/l the PETwas normal. The PET is a useful adjunct to understanding andprescribing peritoneal dialysis, particularly when repeatedtests are compared to a well-defined normal population.     

Changes in coagulation and fibrinolytic activity associated with tracheal intubation

This study was carried out to clarify the effect of tracheal intubation on the coagulation and fibrinolytic system. It was performed on 20 patients (ASA class 1–2) undergoing elective surgery. Before and after tracheal intubation, hemodynamics, ACTH, cortisol, catecholamines, and several coagulation and fibrinolytic factors were measured. Tracheal intubation was accompanied by significant increases in the blood pressure, heart rate, and norepinephrine level. No changes were observed in fibrinopetide A, fibrinopeptide B_15–42, tissue plasminogen activator antigen, plasminogen, fibrinogen, and ₂ plasmin inhibitor. Patients exposed to long intubation time (20 seconds) were found to have a significantly higher level of fibrinopeptide A than patients with short tracheal intubation time (20 seconds) (P 0.05). It therefore can be concluded that the increase in norepinephrine and changes in the hemodynamics following tracheal intubation have no impact on the coagulation and fibrinolytic activity. Also, if the duration of intubation is prolonged, thrombin activity may be promoted.(Gando S, Tedo I, Kubota M, et al.: changes in coagulation and fibrinolytic activity associated with tracheal intubation. J Anesth 6: 80–84, 1994)     

Pneumoperitoneum and peritoneal surface changes: a review

Background Recent evidence suggests that the use of carbon dioxide to create a pneumoperitoneum during laparoscopy can lead to adverse structural, metabolic, and immune derangements within the peritoneal cavity, and that these can be dependent on the specific insufflation gas used. These changes include structural alterations in the mesothelial lining, pH disturbances, and alterations in peritoneal macrophage responsiveness. This contrasts with an apparent systemic benefit associated with laparoscopic, as compared with open, surgery.Methods Recently published clinical and experimental studies related to the effect of pneumoperitoneum on the peritoneal surface are reviewed, and their relevance is discussed.Results Structural changes in the peritoneal mesothelial surface layer such as widening of the intercellular junctions can be demonstrated with electron microscopy. Acidification of the peritoneum in response to carbon dioxide insufflation occurs not only at the peritoneal surface, but also in the underlying connective tissue, resulting in disturbances in the electrical surface charge and the release of various immune mediators such as endotoxin. Pneumoperitoneum also affects the local peritoneal immune environment resulting in alterations in cytokine production and phagocytic function, as well as diminished antitumor cell cytotoxicity.Conclusions Ultrastructural, metabolic, and immune alterations are observed at the peritoneal surface in response to a pneumoperitoneum. Experimental evidence suggests that these changes are carbon dioxide–specific effects. The consequences of these alterations to the local peritoneal environment are not well understood, but they may facilitate tumor implantation within the peritoneal cavity and adversely affect the ability to clear intraperitoneal infections. Further investigation into this area is warranted.     

Initiation of a fibrinolytic system in hepatic resection: The roles of tissue-type plasminogen activator and plasminogen activator inhibitor-1

The factors related to the initiation of fibrinolysis, especially with regard to the tissue-type plasminogen activator (tPA) and the plasminogen activator inhibitor-1 (PAI-1), were investigated in 15 patients who underwent hepatic resection, and the findings were compared between those with normal livers and those with diseased livers. It was found that tPA increased before hepatic division, whereas PAI-1 increased after hepatic division and reached a peak immediately following the operation. Plasminogen decreased during hepatectomy, reaching its lowest point on postoperative day 1, and increasing later. Decreased levels of both plasminogen and the ₂-plasmin inhibitor were considered to be partly due to plasmin formation in the blood. Patients with a diseased liver tended to have higher intraoperative values of euglobulin lysis activity and higher postoperative values of plasminogen activator, but significantly lower postoperative values of ₂-plasmin inhibitor than those with a normal liver. The results of this study suggest that activation of the fibrinolytic system occurs both during hepatectomy and in the early postoperative period, and that patients with a diseased liver are prone to develop hyperfibrinolysis during hepatectomy. Moreover, the increased levels of both tPA and PAI-1 can serve as one of the most sensitive markers for the vital reaction against surgical stress.