Page 28 - Postoperative Intra-Abdominal Adhesions- New insights in prevention and consequences

Chapter 2
[49-53]. This reduction of adhesion formation might be facilitated by more precise tissue manipulation and avoidance of exposure to foreign body materials. Additionally the pneumoperitoneum exerts the effect of a tamponade, thus creating hemostasis during a surgical intervention without ischaemic injury caused by electrocautery or sutures [44]. On the other hand it has been suggested that the gas used during laparoscopy has an effect on adhesion formation by itself. Temperature, the amount of pressure, duration of the operation, humidity and composition of the gas are all factors influencing the process of adhesion formation in various animal studies [54-57]. These hypotheses are supported by a trial in which laparoscopy did not lead to fewer bowel obstructions compared to open surgery for abdominal surgery for cancer [58]. In all, the use of minimal invasive techniques should be promoted since they are associated with a significantly lower incidence of peritoneal adhesions. However, laparoscopy certainly does not prevent adhesion formation.
Adhesion prevention: adjuvants
In the last decades an enormous corpus of work has been carried out in order to find a pharmacological agent capable of influencing postoperative adhesion formation. Since trauma to the peritoneum initiates inflammation as well as the interaction of the fibrinolytic system and coagulation cascade, mainly anti-inflammatory or anticoagulant substances were tested [38]. Steroids, antibiotics, scavengers of reactive oxygen species, statins, non-selective and selective cyclooxygenase inhibitors, heparin and tissue-plasminogen activator (t-PA) are all adjuvants which have been subject to investigation [59]. However, a number of obstacles must be surmounted before agents can be used in adhesion prevention. First, ischaemia and inadequate blood supply are important factors in adhesion formation, but these also decrease systemic drug delivery inhibiting their effectiveness. Second, the peritoneal membrane has an extremely rapid absorption mechanism, limiting the half-life and efficacy of many intraperitoneally administered agents. Third, any anti-adhesion agent needs to act specifically against adhesion formation and not interfere with normal wound healing processes; these processes of adhesion formation and remesothelialization use the same cascade (exudation, coagulation, fibrin deposition and fibroblastic activity and proliferation)[37, 44, 60].
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