| Background and purpose: Since the gastrointestinal anastomosis has been carried out, themedical personnel used different materials and methods for gastrointestinal anastomosis.Hand-sewn anastomosis is a traditional surgery, but its technical is difficult and the success ofthe operation is often related to the personal qualities of the medical staff, which has a higherincidence of postoperative complications. In nearly30years, the stapler gradually entered ourfield of vision, and became popular at home and abroad because of its convenience andshortcut. Along with raising the level of medical technology, stapler was widely applied tocolorectal surgery, radical resection rate of colorectal cancer and anal sphincter preservationrate has increased annually. The medical person found the following problems which aredifficult to solve:1, postoperative anastomotic leakage rate is5%to20%, and anastomoticstricture is4%to10%.2.the staples cause significant foreign body reaction, patients often havea discomfort sense.3. the staples will affect the postoperative CT and MRI examination.4.residual staples may affect the radiation therapy.5.staples can cause formation of intestinal scar,leading to the disappearance of bowel motility, slow down intestinal function recovery, changein bowel regularity. Therefore, seeking a more excellent new anastomosis technique hasbecome a research focus at home and abroad.According to tissue’s healing principle, contact-adhesions-healing,`magneticanastomat can sequestrin the colon rectal stumps and stay in the intestines. Because of thedifferent pressure that magnetic anastomat gives to the intestinal tissue,serosal side of the tissuecan involutive compeletly and keep the blood supply, it will finish the healing process in3-7days. But the pressure of mucosal side is very strong, so the blood supply is blocked and it willlead to the intestinal necrosis. At the same time, the magnetic anastomat will fall of and theintestinal anastomosis is completed. In the process of magnetic anastomosis, the sequestrinforce of the magnetic anastomat affect the firm of anastomtic,the healing process of intestinaltissue and the magnetic anastomat’s shedding time. At present, there is no evaluation criteria ofthe colorectal magnetic anastomat’s magnetic force, and therefore it is necessary to seek ideal magnetic force of the magnetic anastomat.Materrials and methods:1.Materrials: New magnetic compression anastomosis device named the XU-1magneticcompression anastomosis ball composed of2neodymium-iron-boron magnets affixed topolytetrafluoroethylene moldings.2.Methods:Considering of the bursting pressure,tension and colorectal intestinal thicknessin the early experiment, we made each of the5of1000/1000Guass and2000/2000Guass,6000/6000Guass magnetic anastomat. Selecting15female pigs weighing35Kg-50Kg and3-5month age, then dividing them into3groups average randomly(1000Guass group,2000Guass group and6000Guass group). The1000/1000Guass group’s pigs were given the end toend magnetic compression anastomosis by1000/1000Guass magnetic anastomat; The2000/2000Guass group’s pigs were given the end to end magnetic compression anastomosisby2000/2000Guass magnetic anastomat; The6000/6000Guass group’s pigs were given theend to end magnetic compression anastomosis by6000/6000Guass magnetic anastomat. Afterthe magnetic anastomosis, the anastomosis firm level was checked by separating external force.And immediately, we used U.S. Bell companies’ magnetometer to measure the magnetic forceat the anastomotic,0.5cm,1.0cm,1.5cm,2.0cm…away from the anastomotic,until themagnetic force is weakened to be neglected.Then, we measured the surface magnetic force ofthe experimental animals’ abdomen, back, chest, buttocks and anus. Record each experiment’soperation time, and observe and record each experimental pig’s general state, activities, diet,waking time, defecation time, magnetic anastomat’s discharge time. At last, we dissected the3groups of the pigs at time of3,7,11,15,19days after the operation, and observed the bowelspecimens.Result:1. Operative time: The average operation time of the experimental animals is55.2minutesand average anastomosis time is18.5minutes, there was no significant operative difficulties.2.Anastomosis firm level: the magnetic anastomats of2000/2000Guass group and6000/6000Guass group made a firm anastomosis, external force was difficult to separate them. However, the magnetic anastomat was separated by a certain external force.3. Animals postoperative waked after an average of3.6hours, can stood up to walk after6.3hours later. An average of118.5hours after discharge stool. The1000Gauss experimentalgroup shown its ball discharged time was222hours, the experimental group in2000Gaussaverage ball discharged time was158.8hours, the6000Gauss experimental group average balldischarged time was134.8hours.4. Determination of magnetic force display, magnetic force got lager with getting closer tothe anastomotic and gradually attenuated with increasing distance away from the anastomotic.1000Gauss group magnetic force was ignored in1.8cm from the anastomotic,;2000Gaussgroup, the magnetic force was negligible in3.0cm from the anastomotic; the6000Gaussgroups magnetic force was ignored in4.5cm from the anastomotic(Table2).The surfacemagntic force of3groups:the surface magnetic force of abdomen, back, chest, buttocks andanus was0.5.Postoperative complications: three groups of experimental animals anastomotic balldischarge smoothly and there were no anastomotic fistula, intestinal obstruction and othercomplications.6. Specimens observed: Three days after the operation, there was no significant differencebetween the bowel specimens of1000Guass group,2000Guass group and6000Guassgroup.However,1-2days after the discharge of the magnetic ball, the specimens of1000Guassgroup and2000Guass group showed, serosal healing, anastomotic fractured disappeared, nosignificant inflammatory exudate, and no fistula, the proximal intestine had no expansion,andanastomotic patency. The specimen of6000Guass group showed, the serosa of anastomosiswas not completely healed,and inflammatory hyperemia was observed.19days after theoperation, the specimens in3groups showed that anastomotic completely healed, mucousmembrane covered the anastomotic, and scar healing was found by cut off the bowel.Conclusion: Experiments in three different magnetic anastomat,2000Gauss group’sexperimental results showed the level of anastomosis firm, the the anastomosis ball dischargedtime, the degree of anastomotic healing and body surface magnetic force were than those of the ideal. The success of the animal experiments is very important for the further study of themagnetic anastomat. |
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