Experimental Study Of Laparoscopic Segmental Liver Resection In Dogs

Compared with tranditonal surgery, laparoscopic surgery had many advantages of the minimal invasion on the operative animals, sufficient exposure of abdominal organ structure during the operation, the less bleeding, the minimal incision, postoperative mild pain, the less tissue adhesions and more postoperative rapid recovery. It had been widely used in the domains of diagnosis and treatment of animal clinical diseases, livestock production, embryo transfer abroad.Segmental liver resection had been used in the treatment of hepatic abscess, hepatic hydatid cyst, hepatic circumjacent arteriovenous fistula, benign tumor ( hepatic adenoma, hepatic hemangioma, local tubercle hyperplasia et al ), partial malignant tumor or surgical trauma et al. In the medical field, many experimental studies and clinical reports were concerned with laparoscopic segmental liver resection, containing kinds of excisional hepatic methods, excisional hepatic instruments, intraoperative hemostasis methods and studies of complication. However, because of the specificity of hepatic anatomy structure and physiological feature, and limitations of techniques and instruments, laparoscopic segmental liver resection which was considered as a dangerous high technical surgery was more dangerous than the tranditonal laparotomy. In the animals, especially, the study of segmental liver resection was mainly concentrated on the traditional laparotomy in dogs, and related reports were less, while experimental study of laparoscopic segmental liver resection had been no reported at home in dogs.Through establishment of pneumoperitoneum, entering into cannulas and instruments, free liver, dissecting of the hepatic parenchyma, disposal of the hepatic cross-section, irrigation of the abdominal cavity, retrieval of the hepatic specimen and closure of the abdominal cavity, eight healthy mongrel dogs were chosen to perform laparoscopic segmental liver resection in this experiment. During the operation, the body temperature, the respiratory rate, the blood pressure, the pulse oxygen saturation, the heart rate, the end-tidal partial pressure of carbon dioxide and the arterial blood gas were monitored and the data of every time point containing before the anaesthesia, after the anaesthesia-before the pneumoperitoneum, intraoperative 10, 30, 60, 90, 120minutes and postoperative 10minutes was recorded. The venous blood of the forelimb at the before the anaesthesia, postoperative 4 hours and postoperative 1, 2, 3, 4, 5 days before feeding in the early morning was collected in order to detect the white blood cell counting and the neutrocyte ratio. The venous blood of the forelimb at the before the anaesthesia, postoperative 4 hours and postoperative 1, 3, 5, 7, 9, 11, 13, 15 days before feeding in the early morning was collected in order to detect the aspartate aminotransferase, the alanine aminotransferase, theγ-Glutamyl transpeptidase, the alkaline phosphatase, the albumin and the total protein. The venous blood of the forelimb at the before the anaesthesia, postoperative 4 hours and postoperative 1, 3, 5, 7 days before feeding in the early morning was collected in order to detect the blood urea nitraogen, the uric acid and the creatinine. In a month after the operation, the adhesive condition of the abdominal cavity and hepatic healing condition were explored using laparoscope; in three months after the operation, the ptomatopsy was carried out and the adhesive condition of the abdominal cavity and hepatic healing condition were observed.Experiment results: Laparoscopic segmental liver resection had been successfully completed in eight dogs in this experiment. The weight of excisional hepatic lobes was 38.5±18.3g ( range 30~64g ), the time of surgery was 100~140minutes and the total length of incision was 4~5cm. It was not obvious larger bleeding during the operation. In a month after the operation, the complications of bleeding and bile duct leakage did not appear. After the pneumoperitoneum, the blood pressure, the heart rate and the respiratory rate initially decreased, the pulse oxygen saturation and the end-tidal partial pressure of carbon dioxide rise and the body temperature decreased all the time; partial pressure of carbon dioxide in artery rise gradually and was the highest at the intraoperative 10minutes; pH decreased gradually and was the lowest at the intraoperative 10minutes; partial pressure of oxygen in artery had no larger changes. The white blood cell counting, the neutrocyte ratio, the aspartate aminotransferase, the alanine aminotransferase and the alkaline phosphatase were the highest at the postoperative 1 day; the uric acid, the blood urea nitraogen and the creatinine were the highest at the postoperative 4 hours; the albumin and the total protein decreased slightly and were the lowest at the postoperative 1 day; theγ-Glutamyl transpeptidase had no larger changes.Through the experiment results, the following conclusions were drawn:1. Laparoscopic segmental liver resection could be successfully completed in dogs using 4 cannulas portals, dipolar electrocautery dissecting of hepatic lobes and disposal of the hepatic cross-section in the experiment, which demonstrated the feasibility of the technique.2. During the operation, canine clinical signs such as the visual mucosas and reflex of the eyelid, and respiratory and circulatory system such as the pulse oxygen saturation and the blood pressure were monitored and there were no adverse reactions, which could effectively ensure the safety of laparoscopic segmental liver resection in dogs.3. The detection results of six items of hepatic function makers such as the aspartate aminotransferase and the alanine aminotransferase, and three items of renal function makers such as the blood urea nitraogen and the creatinine drew a conclusion that laparoscopic segmental liver resection merely had the influence on the hepatic and renal function in the short term in dogs, but the hepatic and renal function could be quickly recovered in the postoperative period of time.