Effects Of CO₂ Pneumoperitoneum To The Regional Blood Flow Of The Intraabdominal Organs In A Controlled Hemorrhagic Model With Liver Injuries

Liver injury is very common to see and liver is one of the organs that are very easy to be damaged. It can be caused by traffic accident, falling and violence. About 15%~20% of the abdomen injury patients have liver injuries, only less than the rate of spleen injury. One of the most important progresses to cure the patient who has liver injury and stable hemodynamics is try to avoid unnecessary laparotomy (LP). LP is one of the treatments of abdomen injury, but about 5%~20% of these patients have underwent unnecessary LP, and sometimes it can arise to 40%. Laparoscopic surgery (LS) can be used as a diagnosis and therapy method for so many patients who had stable hemodynamics but the impairments of abdominal organs were not sure. LS can cause less surgical trauma. Meanwhile, some of these patients who have simple impairments of abdominal organs can be cured by the LS. But not all the abdomen injury patients are adapt to such a method and the affections of the pneumoperitoneum(PP) to the introabdominal organs are not exactly clear. Much more researches must be done to prevent those potential risks.So we made an animal model with liver impact injury. And color-labeled microspheres (CLM) were used to determine the regional blood flow (RBF) of the introabdominal organs (IAO) within different intraabdominal pressures (IAP) during carbon dioxide (CO2) PP in a controlled hemorrhagic model with liver impact injuries. Meanwhile we observed the change of AST, BUN in blood, and investigated the pathology changes.Conclusions:1. The animal model of liver impact injur has the advantages of simple manipulation of impacting equipment, controllable physical parameters and accuracy and repeatability in impacting sites. The pathology, type and wound state of the liver impact injury in the animals are similar to those seen in clinical practice. They are in the range of gradeâ… to gradeâ…¡according to AAST grading standards. Liver impact injury is complicated with costal fracture and injury of the heart and lungs. The model can be used for analysis of dynamic factors, detection of many indices and imaging diagnosis with SPECT. 2. CLM was used to determine the RBF. Several methods are available for determining RBF, such as direct measurement by Doppler flowmetry or indirect measurement using mucosal tonometry and indocyanine green pharmacokinetic. CLM is easy to handle and can determine the RBFs of several organs in different times. And it do no harm to the animal models.3. We found that when the IAP was 5mmHg, the RBF of the solid organs would be decreased remarkably at 30 minutes under PP, and the RBF of the hollow viscus decreased remarkably at 2 hours under PP. The RBF of the hollow viscus decreased remarkably at 30 minutes under PP only when the IAP was 15mmHg. The changes of the RBF of the IAO are related to the following factors such as the volume of blood lost, the IAP and the duration of the PP. The less blood lost, smaller IAP, shorter duration of PP, the less decrease of the RBF of the IAO. The more blood lost, bigger IAP, longer duration of PP, the more decrease of the RBF of the IAO.4. The decrease of the RBF would cause changes of the organs. The lack of blood perfusion will cause dysfunction of the liver and kidney, impairment of gastrointestinal mucosa, and that will aggravate the trauma of organism. And if the volume of blood lost is more than 40% of WBV, counter shock and blood volume supplementary are much more important than abdominoscopic or LS.