This study was to build a canine portal hypertension model by intra-portal administration of high polymer material polyurethane and organic solvent tetrahydrofuran mixed solutions in order to evaluate the effectiveness of the model. Twelve local crossbreed dogs were selected randomly, with intra-portal administration of 8% (weight/volume) polyurethane-tetrahydrofuran solutions through an incision in the upper abdomen to build the portal hypertension model. We measured the portal vein pressure before modeling, during modeling, and four-, eight-, and twelve-weeks after modeling, respectively. Then we evaluated the effectiveness of the model comparing values of data with those data obtained before modeling started, which were regarded as the normal values. The results showed that the portal vein pressure rose by 2.5 times after the solution administrated instantly as much as that before modeling, and maintained at 1.5 times after 4 weeks. This method presents an easy operation, low animal mortality and reliable model of portal hypertension. Its less abdominal adhesions and its ability in keeping normal anatomic structure specially make it suit for surgical research of portal hypertension.
ObjectiveTo verify the feasibility of a self-designed magnetic anchoring and traction device (MATD) for assisting two-port video-assisted thoracoscopic esophagectomy.MethodsThree Beagle dogs were selected as animal models with age ranging from 1-6 years and weight ranging from 8-12 kg, and they underwent two-port video-assisted thoracoscopic esophagectomy after general anesthesia. We used the MATD to retract the esophagus to different directions, which assisted mobilizing esophagus, detecting the nerves along esophagus and dissecting paraesophagus lymph nodes. The operation time, blood loss and feasibility of the MATD were recorded.ResultsWith the aid of the MATD, we successfully retracted and mobilized the esophagus, detected the nerves and dissected the lymph nodes in three Beagle dog models. During the operation, the MATD provided sufficient and steady traction of esophagus to achieve a good exposure of the operative field, effectively decreasing the interference between working instruments. The MATD worked well. The mean operation time was 30 min, and the mean intraoperative blood loss was about 10 mL.ConclusionIt is effective to use the MATD to assist retracting esophagus during video-assisted thoracoscopic esophagectomy. The magnetic anchoring and traction technique can assist to expose the surgical field, decrease the interference between the working instruments and have the potential clinical application.
The magnamosis device for stage-one repair of the rectovaginal fistula consists of two arc magnets. Drawing the interrupting thread along the fistula margin via the vaginal side, and pulling the string to arrange the magnets at the fistula base along the long axis of the vagina, we made the magnamosis device automatically clipped to seal the fistula. After removing the threads we kept the device for 2~4 weeks till the natural detachment of it when the compressed tissue in between healed after vascular necrosis. This device utilizing the unique ability of magnamosis to fulfill anastomosis under inflammatory infected state reduces the current high relapse rate and colostomy drawbacks of the conventional rectovaginal neoplasty.
ObjectiveTo summarize the recent development of the magnetic compression anastomosis in surgery. MethodsThe abroad and domestic relevant literature about magnetic compression anastomosis was extensively reviewed, and comprehensive analyzed. ResultsMagnetic compression anastomosis in the reconstruction of the body lumen is a simple and effective way; laparoscopy combined with magnetic compression anastomosis has the advantages of small wound and quick recovery. Magnetic compression anastomosis has been increasingly used in cl inical practice. But its mechanism has not been fully revealed, and it is difficulty in expelling out of the magnet for the gastrointestinal and certain large-size lumen, so further research and optimization are still needed. ConclusionRelative to the traditional manual suture, magnetic anastomosis has great advantage, especially a combination of magnetic compression anastomosis and minimally invasive surgery has bright prospects for development.
The earliest research of magnetic surgery was the application of magnetic anastomotic device to anastomose the blood vessels. Now, it has been widely used for anastomosis of blood vessels, gastrointestinal tract and biliary tract. The concept of "magnetic surgery" was named firstly by LU Yi in 2010 and magnetic surgery was classified into magnetic anchoring technique, magnetic navigation technique, magnetic compression technique, magnetic tracing technique, and magnetic suspension technique. The applications of magnetic surgery in the field of thoracic surgery mainly include magnetic compression technique, magnetic anchoring technique and magnetic navigation technique. This paper summarizes the application of magnetic surgery in thoracic surgery and prospects its future development in the field of thoracic surgery.
ObjectiveTo investigate the feasibility of using magnetic beads to locate small pulmonary nodules.MethodsTwelve rabbits were randomly divided into two groups, 6 in each group. One group underwent thoracotomy after anesthesia and the other group underwent percutaneous puncture under the guidance of X-ray. One and two cylindrical tracer magnets (magnetic beads) with a diameter of 1 mm and a height of 3 mm were injected adjacent to the imaginary pulmonary nodules in left lung in each group. The magnetic beads beside the imaginary nodules were attracted by a pursuit magnet with a diameter of 9 mm and a height of 19 mm. The effectiveness of localization by magnetic beads were determined by attraction between tracer and pursuit magnets.ResultsAll processes were uneven in 12 rabbits. There was micro hemorrhage and no hematoma in the lung tissue at the injection site of the magnetic beads. When tracked with the pursuit magnets, there was one bead divorce in cases that one bead was injected, but no migration or divorce of the magnetic beads in cases that two magnetic beads were simultaneously injected to localize the small pulmonary nodules.ConclusionThe feasibility of using magnetic beads to locate small pulmonary nodules has been preliminarily verified.
ObjectiveTo investigate the feasibility of magnamosis rings designed based on magnetic compression technique in esophageal anastomosis reconstruction.MethodsAccording to the anatomical characteristics of esophagus in SD rats, the esophageal magnamosis rings were designed. SD rats were used as animal models (n=10, 5 males and 5 females) to complete the magnetic anastomosis reconstruction of the cervical esophagus using magnamosis rings, and the operation time, animal survival, postoperative complications, magnetic rings excretion time were recorded. Two weeks after operation, the rats were killed, and the esophageal anastomotic specimens were obtained. The blasting pressure of the anastomotic site was measured and the formation of the anastomotic site was observed with naked eyes.ResultsEsophageal magnamosis was successfully performed in 10 SD rats, and the median operation time was 11 (8-13) min. All rats survived without anastomotic leakage, anastomotic stenosis, or magnetic rings incarceration. The magnetic rings were discharged after 8 (5-10) days and the burst pressure was higher than 300 mm Hg. Visual observation showed that the anastomotic muscle healed well and the mucosa was smooth.ConclusionThe magnetic compression technique can be used for anastomosis reconstruction of esophagus, which has the advantages of simple operation and reliable anastomosis effect, and has clinical application prospect.
Magnetic anchoring and traction technique is one of the core technologies of magnetic surgery. With the "non-contact" traction force of the outer magnet on the inner magnet, we can drive the inner magnet and the gripper to multiple directions, and pull tissue or organ to required position in operations, so as to get a clearer surgical field of view. On the basis of the previous animal experiments, we applied magnetic anchoring and traction device in 3 human (males aged 63-71 years) thoracoscopic esophagectomies. Using the magnetic anchoring device, we could pull the esophagus dorsally or ventrally to assist in exposing the anatomical plane without special equipment or pleural puncture for retraction of the esophagus. The interference between operating instruments reduced. The mean blood loss in operation was 83 mL, the mean total operation time was 253 min and the mean length of hospital stay was 10 d. Postoperative follow-up showed that all 3 patients had good short-term prognosis. There was no swellling or pain in magnetic anchoring zone of chest wall.