Optimization of preparation method of rectovaginal fistula animal model based on principle of magnetic compression technique
Objective To investigate the feasibility of the optimally designed"I"shaped structure mag-net based on the principle of magnetic compression technique for the preparation of rectovaginal fistula animal model.Methods Using 10 New Zealand female rabbits as the model animals,two self-designed magnets were inserted through the vagina and anus respectively after anesthesia,and the two magnets were adjusted to the appropriate position and made them attraction each other to form a magnet-rectovaginal partition-magnet structure.When the compression tissue between the magnets became ischemic necrosis and fell off,the two magnets formed the"1"shape structure and were located in the stoma of rectovaginal fistula to prevent the stoma from becoming smaller or even closing itself.The operation time and rectovaginal fistula formation time were recorded.The experimental rabbits were killed in postoperative 2 weeks,and the rectovaginal fistula specimens were obtained.The formation of fistula orifice was observed and the size of fistula orifice was meas-ured.Results The animal model of rectovaginal fistula was successfully prepared in all 10 experimental rab-bits.The procedure of intraoperative magnet placement was smooth and the operation time was(1.55±0.65)min.The experimental animals were generally in good condition after surgery,and the fistula orifice was formed on postoperative(4.80±0.75)d.After taking the gross specimen of rectovaginal septum in postopera-tive 2 weeks,the magnet was removed.The fistula orifice of rectovaginal fistula was visible with the diameter of(5.86±0.38)mm.Conclusion The"I"shaped structure magnet designed based on the principle of mag-netic compression technique could be used in the preparation of the rectovaginal fistula animal model.Its oper-ation is simple with high success rate of model preparation and good uniformity in fistula orifice.
magnetic compression techniquemagnetic surgeryrectovaginal fistulamagnetanimal model