Animal Experimental Study Of Neodymium-iron-boron Magnetic Pressing Technique In Intestinal Anastomosis

Objective: The feasibility of this technique in animal colon anastomoses was verified by establishing a magnetic squeeze anastomotic model of the rabbit colon,and the fecal transfer function of the squeeze anastomotic mouth was evaluated.2.In order to compare the effect of the two kinds of operation,the animal sequence of magnetic pressing and manual suture was established.Methods:1.Eight rabbits were selected and a certain size of magnet was placed in the colon to achieve the side-to-side squeezing anastomosis.X-ray fluoroscopy was carried out from the forth day after operation to observe the position change of squeezing magnet.After the formation of anastomotic opening,the formation of anastomotic opening was evaluated by means of colonography,anatomical observation and histopathological examination,and the intestine between anastomotic openings was ligated to evaluate the squeezing anastomotic opening Fecal diversion function.2.Thirty two rabbits were randomly divided into two groups: group A and group B.all rabbits were operated to transect the colon.In group A,16 rabbits were used as experimental group to perform end-to-end anastomosis by magnetic pressing,while in group B,16 rabbits were used as control group to perform end-to-end anastomosis by manual suture.The anastomosis time of each rabbit was recorded and the survival of the two groups were observed.On the 9th day after the operation,8 rabbits in the experimental group and 8 rabbits in the control group were selected and killed under deep anesthesia.The anastomotic specimens were taken out for observation.The anastomotic effects of the two methods were compared by burst pressure measurement,he staining and Masson staining.On the 16 th day after the operation,the remaining rabbits in the two groups were killed under deep anesthesia,and the anastomotic effect of the two methods was compared in the same way.Results: 1.On the 6th to 8th day after operation,all the magnets of 8 rabbits were removed,1 rabbit suffered from intestinal obstruction,the other 7 anastomoses were well formed,the anastomoses of colonography were clear,no leakage of contrast agent was found,the mucosa of anastomoses of 2,3,5 and 7 rabbits was smooth,without perforation,bleeding and anastomotic leakage,and the pathology showed that all layers healed well.Among the three rabbits with intestinal ligation,rabbits 1 died of intestinal obstruction on the 6th day after operation,and rabbits 4 and 6 survived for a long time.On the 30 th day after operation,the anastomotic opening was dilated and no leakage of contrast agent was found on colonography.The diameter of the anastomotic opening was enlarged and the mucosa was smooth.Feces passed through the anastomotic opening.2.In the further control experiment,the anastomotic time was(89.44 ± 16.75)s in theexperimental group(group A)and(371.44 ± 43.18)s in the control group(group B)In the experimental group,the squeezed magnets were all removed 6-8 days after the operation.One rabbit died on the 6th day after the operation,which was confirmed as postoperative intestinal obstruction by anatomy.In the control group,two rabbits died on the 3rd and 6th day respectively,which was confirmed as postoperative anastomotic leakage and abdominal infection by anatomy.On the 9th day after operation,the anastomotic mucosa in the experimental group was smooth,without bleeding and intestinal fistula,and the scar hyperplasia was slight.In the control group,there was no bleeding and perforation in the anastomotic mucosa,and the suture and scar hyperplasia could be seen in the anastomotic inner surface.Histopathology: the anastomotic tissues in both groups healed layer by layer,but fibrous tissue hyperplasia and inflammatory cell infiltration were more obvious in the manual suture group.On the 9th day after operation,the bursting pressure of the experimental group was(130.00 ± 8.40)mmHg,while that of the control group was(118.75 ± 11.44)mmHg,P < 0.05,with statistical significance.On the 16 th day after the operation,the remaining rabbits were killed,7 in the experimental group and 6 in the control group.The bursting pressure of the anastomose was(139.71 ±6.10)mmHg in the experimental group and(133.33 ± 7.87)mm Hg in the control group,P > 0.05,with no significant difference.Conclusion: 1.Magnetic pressing technique is an effective way to achieve intestinal anastomosis in rabbits.2.Compared with the manual suture,the operation of magnetic press anastomosis is simpler,the operation time is shorter and the complications are lower.On the 9th day after operation,the magnetic press anastomosis has higher anastomotic strength,while on the 16 th day after operation,there is no statistical difference in the anastomotic strength between the two groups,and the magnetic press anastomosis has more advantages in the early postoperative period.