| Laparoscopic surgery has evolved and expanded greatly over the past decade. Since its first successful entry into general surgery with the advent of laparoscopic cholecystectomy in the late 1980s, laparoscopic surgery has been incorporated to various degrees into almost every aspect of abdominal surgery. Laparoscopic liver surgery is in a developing field now but formal segmental resections are still remaining diminutive percentage. There is an abundance of evidence reflecting the benefits of laparoscopic cholecystectomy and some of these benefits have been linked to the decreased metabolic and immune responses involved. Multiple clinical studies initially comparing open to laparoscopic cholecystectomy clearly demonstrated a significant reduction in postoperative pain, hospital stay, perioperative morbidity, and convalescence. Laparoscopic liver surgery is a field in its infancy, such basic and clinical studies are still needed to investigate.At first, we need a animal model of laparoscopic hepatectomy for basic research.. It is required that the procedure is feasible, safe, reproducible, and formal segmental resection can be accomplished. At the same time, it is reported that cytokines present important influence in inflammatory response induced by operation and trauma, so it is significant to observe dynamic change of serum TNF-a & IL-6 level.So we planned to develop a new animal model of laparoscopic partial hepatectomy in the rabbit. Corresponding to various resection volume, various laparoscopic groups and corresponding open groups were installed, dynamic change of serum TNF-a & IL-6 level was observed and compared simultaneously.Materials and Methods40 male New Zealand big rabbits provided by animal center of ZhejiangUniversity with body weight ranged from 2.0-2.5kg were divided into 4 groups randomly. Group A(n=10): underwent laparoscopic liver resection of left internal lobe;Group B(n=10): underwent open liver resection of left internal lobe;Group C(n=10): underwent laparoscopic liver resection of left internal and lateral lobe;Group D(n=10): underwent open liver resection of left internal and lateral lobe. All groups were anesthetized by intravenous injection(0.3ml/kg) of 846 mixture liquid. Operation procedure: Group A> C(laparoscopic groups), as it is a gasless laparoscopic operation, a subcutaneous suture was firmly placed subcutaneously in the umbilical abdominal wall and it is attached to a lifting device to create a sufficiently wide working space. The 0° laparoscope(Smith & Nephew ?) used was 2mm in diameter. All the instruments (endo grasp and endo shears)(Auto Suture ?) were 5mm in diameter. Three ports were made longitudinal from xiphoid process to umbilical region. A pretied loop ligature: 2-0 Surgitie(Auto Suture ?) was then placed around the base of liver lobe under endoscopic guidance. The ligature was tied firmly. Resection was performed with endo shears about 3-5 mm distal to the ligature;Group B> D(open groups), the conventional operation was done with a long incision about 7cm. The operative time, blood loss, mortality or morbidity, specimen weight and residual liver weight of 7th day, body weight of preoperative and 7th day, abdominal adhesion formation, healing of incision and liver were measured or estimated. Serum levels of ALT, AST, TNF-a(ELISA), IL-6(ELISA) were investigated at preoperative, 12h, 24h, 48h, 72h, 7d after operation. HE stain liver specimen was observed under microscope.Results All four groups received operation favorably, no conversion to the opentechnique was necessary in Group A&C. All rabbits received normal diets and showed sensitive feedback the day after operation. No intra- or perioperative mortality or morbidity (bleeding, biliary leakage, infection) was observed. All animals survived in 7 days and showed no wound infections. Group A(laparoscopic left internal lobectomy) was compared to Group B(open left internal lobectomy);while Group C(laparoscopic left internal & lateral lobectomy) was compared to Group D(open leftinternal & lateral lobectomy): there is no apparent difference in blood loss during the intervention(P>0.05) while operative time was significant prolonged(P<0.01). All rabbits had a significant weight loss on 7th day(P<0.01) regardless of whether one or two lobes had been resected, but no difference among the four groups in body eight(P>0.05). There is no apparent difference in specimen weight and residual liver weight between Group A and Group B while Group C and Group D(P>0.05).Serum ALT and AST change: serum ALT concentration elevated significantly in each groups postoperatively during 24h (P<0.01) and went back to normal level in 7days;serum AST concentration elevated significantly in each groups postoperatively during 12h (P<0.01) and went back to normal level in 3-7days, while no difference in ALT & AST change among the four groups(P>0.05).Serum TNF-a change: Group A(laparoscopic left internal lobectomy) was compared to Group B(open left internal lobectomy), serum TNF-a concentration elevated postoperatively in two groups, serum TNF-a concentration 72h after operation in Group A was significant lower than Group B(P<0.05);Group C(laparoscopic left internal & lateral lobectomy) was compared to Group D(open left internal & lateral lobectomy), serum TNF-a concentration elevated postoperatively in two groups, serum TNF-a concentration 72h after operation in Group C was compared to Group D(P=0.08);There is no apparent difference in TNF-a change between Group A and Group C while Group B and Group D.Serum IL-6 change: Group A(laparoscopic left internal lobectomy) was compared to Group B(open left internal lobectomy), serum IL-6 concentration elevated significantly postoperatively in two groups, serum IL-6 concentration 24h & 48h after operation in Group A was significant lower than Group B(P<0.05);Group C(laparoscopic left internal & lateral lobectomy) was compared to Group D(open left internal & lateral lobectomy), serum IL-6 concentration elevated significantly postoperatively in two groups, serum IL-6 concentration 48h & 72h after operation in Group C was significant lower than Group D(P<0.05);There is no apparent difference in IL-6 change between Group A and Group C while Group B and Group D.Pathologic change: adhesion formation under incision was apparent in opengroups(B & D) while no difference around hepatic region between laparoscopic groups and open groups;the residual liver was swelled and the margin was a little blunt, the resection margin healed well surrounding by some connected tissue, no intra-abdominal abscess formation and no sign of former bleeding at the resection margins, there was no sign of bile leakage encountered in the abdominal cavity or on the resection surface of the liver;observed under microscope, hepatic lobule kept integrated after operation, enlarged liver cells could be seen in side zone of lobule, which was more apparent in left internal & lateral lobectomy groups(C & D), the nuclear and nucleoli were enlarged, the karyoplasm and cytoplasm were stained weak, vesicle can be seen in some liver cells.Conclusions1. Set up a new animal model of laparoscopic partial hepatectomy in the rabbit.2. Compare to open hepatectomy, laparoscopic hepatectomy showed more diminutiveinfluence on serum TNF-a & IL-6 change.
|
PDF Full Text Request