Peritoneal Fibrinolytic Response to Various Aspects of Laparoscopic Surgery: A Randomized Trial Walter J.A. Brokelman, M.D.,* ,1 Lena Holmdahl, M.D., Ph.D.,† Maria Bergström, M.D., Ph.D.,† Peter Falk, B.Sc.,† Jean H.G. Klinkenbijl, M.D., Ph.D.,* and Michael M.P.J. Reijnen, M.D., Ph.D.* *Department of Surgery, Alysis Zorggroep, Locatie Rijnstate, Arnhem, The Netherlands; †Department of Surgery, Sahlgrenska University Hospital/Östra, Göteborg University, Göteborg, Sweden Submitted for publication April 24, 2006 Background. Peritoneal fibrinolysis is important in peritoneal wound healing processes and adhesion for- mation. The peritoneal fibrinolytic response to lapa- roscopy 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 lapa- roscopic 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 concentra- tions 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 mea- sured parameters. Conclusion. Short-term laparoscopy does not affect the peritoneal fibrinolytic activity. The used intra- abdominal pressure, light intensity and choice of dis- section device do not affect peritoneal activity during short-term laparoscopy. © 2006 Elsevier Inc. All rights reserved. Key Words: peritoneum; fibrinolyse; adhesions; lapa- roscopy. INTRODUCTION Endoscopic surgery has developed rapidly in the last decades. Endoscopic surgery minimizes the surgical trauma, thereby reducing recovery time and the inci- dence of postoperative complications [1]. Few studies have suggested that this strategy might also reduce the incidence of peritoneal adhesion formation [2, 3]. Abdominal surgery elicits an inflammatory response, which is accompanied by the formation of fibrin in the peritoneal cavity. Under normal circumstances, fibrin is lysed rapidly by the fibrinolytic system. After con- ventional abdominal surgery, however, the equilibrium between coagulation and fibrinolysis is disturbed, in favor of the coagulation system [4, 5]. Thus, fibrin will form deposits that are a matrix for ingrowth of fibro- collagenous tissue and may eventually develop into permanent fibrous adhesions [6, 7]. By producing both activators and inhibitors of fibri- nolysis, the peritoneum is decisive in the genesis of adhesions. Tissue-type plasminogen activator (tPA) is the main peritoneal plasminogen activator [4]. A sec- ond, but less potent plasminogen activator is uroki- nase-type plasminogen activator (uPA), which also may play a role in tissue remodeling processes [8]. Their activity is restricted by plasminogen activating inhib- itors, predominantly type 1 (PAI-1). High peritoneal PAI concentrations have been associated with adhe- sion formation [9]. Laparoscopic surgery induces the activation of both coagulation and fibrinolytic pathways in plasma [10]. The effect of laparoscopy on the peritoneal fibrinolytic response is merely unknown. Endoscopic surgery in- duces new entities in the abdominal cavity including the intense illumination of the peritoneal cavity and a 1 To whom correspondence and reprint requests should be ad- dressed at Department of Surgery, Alysis Zorggroep, locatie Rijn- state, Wagnerlaan 55, 6815 AD Arnhem, The Netherlands. E-mail: w.brokelman@planet.nl. Journal of Surgical Research 136, 309 –313 (2006) doi:10.1016/j.jss.2006.07.044 309 0022-4804/06 $32.00 © 2006 Elsevier Inc. All rights reserved.