Evaluation Of A New Laparoscopic Anastomotic Technique: An Animal Experimental Study

Background and objectivesThe technique of laparoscopy has developed for more than a hundred years. And a lot of procedures can be successfully performed by it. Now it is a smooth stage when investigators are looking for new laparoscopic skills, potential use and new procedures in which the technique can be used. But some new surgical ideas or appliances cannot be used in patients directly, it's necessary to complete the concerned animal experimental study. However, reports on experimental study of laparoscopic anastomosis are scarce, especially the new laparoscopic anastomotic technique breaking the conventional model. Given the comparability of small intestine and biliary duct on histogenesis, structure and the analogical performance of intestinal anastomosis and biliary-enteric anastomosis when the common bile duct is dilated, inorder to reduce the quantity of big animal used in the experiment and the cost of making the animal model, to make the most of current laparoscopic appliances, we design such an experiment that a side-to-side small intestinal anastomosis is performed openly and simply with a titanium clip instead of Endo-GIA in rats to simulate the bilioenteric anastomosis. Thus the small intestinal anastomotic animal model is engendered. And a comparison between the anastomosis performed with suture and titanium clip is drawn. The aim of this study is :(1)to study the feasibility and safty of the new laparoscopic anastomosis in the new technique, (2) to evaluate the new anastomotic technique with titanium clip compared with the anastomotic technique with suture, (3)to study the feasibility and future of the new technique in the procedure of laparoscopic bilioenterostomy. MethodsForty healthy Wistar rats, weighing 300g or so, were used for the experiment, half of whom were male. They were divided randomly into two groups according to the treatment they received with half male rats in each group. Rats were anesthetized with intraperitoneal 10% hydrochloroaldehyde(0.3ml/kg body wt), and an upper-abdominal, subxiphoid 0.5cm, midline incision, measuring approximately lcm, was made in each rat to permit access to the peritoneal cavity. Openly the segments 10cm and 20cm distally to the beginning of the ileum were pulled together parallelly with the tractive stitches. Group I (n=20) (suture group): a small enterotomy, about 0.9cm, was made along the antimesenteric border with a scalpel. Then the procedures of side-to-side intestinal anastomosis were conventionally completed in a single layer with a continuous suture(5/0, unabsorbable) openly. Group II (n=20) (titanium clip group): A small enterotomy was made at the end of each bowel segment near the proximal tractive stitche. The enterotomy should be big enough for a limb of a clip applier to put into. Each limb of the clip applier with titanium clip was put into a small enterotomy, and the clip applier was fired. The intestinal wall clipped would be short of blood, and putrescence occurred. The adjacent normal tissue would conglutinate to form the anterior and posterior walls of the anastomosis. Thus the procedure of side-to-side intestine anastomosis was accomplished with titanium clipopenly. The time spent in making animal model was recorded. Anesthesia was induced and all of the rats were sacrificed 7 days postoperatively. A segment surrounding the anastomosis was resected to investigate the anastomosis, to mensurate the bursting pressure. Standard microscopic sections were prepared at 5[im and stained with Masson trichrome stains. Then the collagen content of the scar tissue in the anastomosis was tested respectively with HPIAS-1000, high-resolution pathologic image analysis system under 10 x 40 magnification. And the collagen content of the scar tissue was compared between group 1 and group 2. Results(1) The anastomotic time for the titanium clip group was significantly decreased(44.10±5.57) compared with that for the suture group(53.80±9.21) (P<0.05).(2) The rats were sacrificed and the anastomotic samples were tested 7 days after the operations to find that the anastomoses had been constructed both in group I and group II. All the anastomoses in suture group were good without anastomotic leak except for a little dwindlement in size. The inner wall was smooth. There were two anastomotic leakages in titanium clip group, which occurred in the small enterotomy. The inner wall was smooth as well. And there were not dwindlement found.(3) The bursting pressure of the anastomoses for the titanium clip group was decreased(102.35±23.76)mmHg (n=20) compared with that for the suture group (156.30±53.88)mmHg (n=20) (P<0.05).(4) The difference of mean grayscale of group 1 (96.36±2.79) (n=20) and group II (99.02±3.62) (n=20) (P>0.05) was not significant. That was to say the collagen content of the scar tissue in the anastomoses between group I and group II was equivalent.Conclusions(1) It's feasible to perform the laparoscopic anastomosis with the new technique except that some idiographic procedures should be ameliorated. Then its safety will be increased. There are a lot of advantages in theory if the new technique can be used practically though there are many questions to be resolved.(2) Anastomotic quality is less with the new laparoscopic anastomotictechnique than that with conventional stitches. There is something to do with it. But with the new anastomotic technique some operational time can be saved to avoid the complications anaesthesia induces.