| BackgroundIn 2012,there were approximately 1.36 million new cases of colorectal cancer in the world.Colon cancer is the third most common malignant tumor in the world.The incidence of males ranks third in the world,and women rank second in death.The number of death is about 690,000,and it is the fourth in the mortality rate of malignant tumors.About 45%of these cases occur in developing countries.Since the incidence of colorectal cancer is increasing worldwide,surgical resection is the main method for treating tumors,and the most ideal surgical procedure is to be able to completely remove the tumor while preserving the normal defecation function of the anus,to the greatest extent without affect the quality of life of patients after surgery.However,many cases are due to complex tumor growth conditions,such as the tumor growth position is too close to the anus,the tumor invading the surrounding tissue or blood vessels,the poor degree of differentiation,etc.,which determines the anus of the operation needs to be removed permanently.The patient’s feces will be permanently discharged from the intestine stoma after the operation,.Due to the permanent loss of the patient’s ability to dismantle the stool after surgery,and the stool is not formed,the postoperative quality of life of the patient is significantly reduced.PurposeTo study the visualization system and pressure sensing system of intelligent artificial anal occluder,including the design of the visual system design,schematic,circuit design,software and hardware design and assembly,prototype production,finished product inspection;animal model of enterostomy Preparation;experimentally validated the effect of the visualization system combined with the pressure sensing function on the animal model Tibetan mini-pigs,supporting the final application of the artificial anal occluder in combination with the pressure sensing function visualization system.Through the independent research and design of new methods of ostomy,to ultimately improve the quality of life of patients with enterostomy.Research methods and results1.Artificial anal occlusion device model making（1）Formulate a preset plan:consult the literature,and measure the inner diameter of the colorectal lumen of the experimental Tibetan mini-pigs with a body weight of about 30 kg in the pre-experiment.As a basis for the shape and size design of the occluder model,a preset plan is formulated.And draw the engineering production line drawing and three-dimensional color picture.（2）Hardware debugging and software programming:The visualization system includes the design and assembly of software and hardware to form a digital product.The hardware includes:miniature camera lens,image CCD photoelectric conversion system,illumination source system,image acquisition,storage and display,and system control module.The software includes an efficient software system that processes images and adjusts image contrast,brightness and color.（3）Sample preparation:Find the sample preparation unit,according to the three-dimensional color map of the design scheme we provided,and the engineering production line diagram,quickly assemble into a machine to produce an occluder device that conforms to the animal model.（4）Determining the final sample:The visualized artificial anal occluder includes a base,a stoma plug,and a visualization system.The pedestal is a circular annular sheet with adhesive at the bottom.The inner ring of the pedestal has a cylindrical shape and is about 2 cm high.It is placed around the stoma tube to stabilize and support the intestinal tract.The cover of the base is similar to the umbrella,and the umbrella surface is the cover of the inner ring pillar.The inner ring can be sealed,the umbrella shaft is a cone,the cone bottom is connected to the umbrella surface,and the cone can be inserted into the stoma.The intestine plays a blocking role,improves the shape of the vertebral body to make it more conformable to the shape of the intestine,and has a miniature camera mounted at the tip of the cone.The micro camera can distinguish the nature of the contents of the intestine and deliver this signal to the stoma.On the surface prompting device,the patient knows the defecation signal through the prompting device.When the patient decides to defecate,the ostomy plug is removed,and the fecal bag is installed on the inner ring of the pedestal to discharge the stool.After partial cleaning,the patient is again sealed with the ostomy plug.The inner ring seals the intestine and the entire device can be recycled.2.Establishment of an enterostomy modelAll mini-pigs were acclimated to the environment for 3 days before the experiment,fasted for 24 h before surgery,and banned for 8 h.After the preoperative preparation,the pig intestine stoma model was established according to the extraperitoneal colostomy.3.Animal experiment3.1 Comparison of animal experimental research on the effect of artificial anal occluder combined with common anal occlude.3.1.1 Determination of leak rateThe visual occluder group and the common occlusion group were respectively sealed with corresponding occlusion devices.The number of stoma leakage in the first,fourth and eighth weekend（8h）after the placement of the sealing device was calculated for the two groups of animals respectively.The exudation of the contents of the stoma is calculated as one time.The sealing effect of the anal occluder is judged by recording the number of leakage of the stoma.3.1.2 Determination of accuracyThe visual occluder group and the common occlusion group were respectively sealed with corresponding occlusion devices.The Times of correct defecation in the first,fourth and eighth weekends（8h）after the placement of the plugging device were calculated respectively for the animals in the visualization group and the general plugging device group.When the intestinal contents were discharged after the opening of the plugging device,the defecation was recorded as correct.The control group opened the occlusion device every 1h/time to observe whether there was stool overflow.The experimental group observed that there was stool in the camera to open the occlusion device.3.1.3 Visual and microscopic view（a）Observing the intestines around the intestine fistula by the naked eye for redness,surface mucosal tissue ischemia,or bleeding,necrosis,and infection around the stoma.（b）Before blocking,at the end of the first,fourth and eighth weeks after sealing,a small amount of intestinal mucosal tissue（about 0.5Xlcm）was taken from the ostomy of the experimental and control animals,and the intestines of the lesion had been harvested.The wall tissue was immersed in 10%formalin for HE staining,and the absolute values of neutrophils and lymphocytes in the tissues under 40 high-power fields were calculated.3.1.4 Western blot,Qpcr and Elisa detectionBefore the plugging,on the 1st,4th,and 8th week after the plugging,a small amount of intestinal mucosal tissue（about 0.5Xlcm）was taken from the ostomy at the ostomy of the experimental and control animals,and the intestinal wall tissue of the wounded part was removed.The cells were stored in a-20℃ refrigerator,and the intestinal tissues were subjected to western blot,Qpcr and Elisa detection to detect the expression of inflammatory factors IL-4,IL-6 and TNF-α at the DNA molecule level.3.1.5 Immunohistochemistry:Before blocking,at the end of the first,fourth and eighth weeks after sealing,a small amount of intestinal mucosal tissue（about 0.5Xlcm）was taken from the ostomy of the experimental and control animals,and the intestines of the lesion had been harvested.The wall tissue was immersed in 10%formalin for immunohistochemistry,and the expression of inflammatory factors IL-4,IL-6 and TNF-α in intestinal tissues was observed.4.Statistical analysis:Data processing was performed on SPSS 13.0 statistical software.All data were expressed as X±s.Multiple independent sample nonparametric tests（Kruskal.Wallis test）were used to compare the presence or absence between the two groups at each time point.Significant differences,and multiple related samples of the Friedman test,were mainly used to test the presence or absence of time effects in each group.The above results were considered statistically significant at P<0.05.Results1.The effect of different groupings on ostomy complications1.1 Comparison of leakage between the two groupsThere was no significant difference in leakage rate between the two groups before the closure.The leakage rate between the visual occluder and the normal occluder group at 1st,4th and 8th week after closure was significantly different（P<0.05）.There was no significant difference in the leakage rate between the first week and the fourth week after the blocker was blocked,but there was a significant difference between the first week and the fourth week,the fourth week and the eighth week（P<0.05）.There was a significant difference between the first week and the fourth week of the visualization group（P<0.05）.There was no significant difference between the 4th week and the 8th week.The overall leakage rate decreased with time.1.2 Comparison of the accuracy of the two groupsThere was no significant difference in the accuracy between the two groups before the closure.The accuracy of the visual occluder and the common occluder group at 1st,4th and 8th week after closure was significantly different（P<0.05）.There was no significant difference in the accuracy between the first week and the fourth and eighth weeks after the blocker was blocked,and the accuracy did not change with time.The accuracy of the first week and the fourth and eighth weeks after the visualization group were significantly different（P<0.05）,and the overall accuracy decreased with time.1.3 inflammatory cell infiltrationThere was no significant difference in neutrophil count between the two groups before occlusion.There was significant difference in the number of neutrophils between the visual occluder and the occluder group at 1st,4th and 8th week after closure（P<0.05）.The number of neutrophils in the first,fourth and eighth weeks after blocking in the general occluder group was significantly different（P<0.05）,The number of neutrophils increased significantly in the first,fourth and eighth weeks after closure compared with those before the closure（P<0.05）.The number of neutrophils in the first,fourth and eighth weeks after the closure of the visual occluder group was significantly different（P<0.05）,There was no significant difference in the number of neutrophils between the 8th week after the closure and the occlusion.The overall trend of the two groups is first rising and then falling to normal（or near normal）.There was no significant difference in the number of lymphocyte counts between the two groups before the closure.The number of lymph nodes in the visual occluder was significantly different from that in the normal occluder group at the 1st,4th,and 8th week after closure（P<0.05）.The number of lymphocytes in the first,fourth and eighth weeks after blocking in the general occluder group was significantly different（P<0.05）,At the 1st,4th,and 8th week after closure,the lymphocytes were increased to different degrees before the closure（P<0.05）.The number of lymphocytes in the first,fourth and eighth weeks after the closure of the visual occluder group was significantly different（P<0.05）.There was no significant difference between the 8th week after the closure and the lymphocytes before the closure.The overall trend of the two groups is first rising and then falling to normal（or near normal）.2.Effects of different groups on inflammatory side effects afier occlusion2.1 Western Blot,Qpcr,Elisa detection of inflammatory factors IL-4,IL-6,TNF-αexpressionWestern Blot,Qpcr and Elisa showed that the expression levels of inflammatory factors IL-4,IL-6 and TNF-α increased at the first and fourth weeks in the visual occluder group and the general occluder group（P<0.05）,and the increase in the general occluder group was more obvious（P<0.05）.The expression levels of il-4,il-6 and TNF-α in the visualization group were restored to the pre-occlusion level at week 8 after occlusion（P>0）.05),while the expression levels of il-4,il-6,and TNF-a-a in the group with ordinary blocker were all higher than those before the block in the eighth week after the block（P<0）.05).2.2 Immunohistochemical staining to verify the expression of inflammatory factors IL-4,IL-6 and TNF-α in intestinal tissuesImmunohistochemical staining showed that the expression levels of inflammatory factors IL-4,IL-6 and TNF-α increased at the first and fourth weeks in the visual occluder group and the general occluder group（P<0.05）.And the increase in the general occluder group was more significant（P<0.05）,in which the expression level of IL-6 and TNF-α reached the highest peak at 1 week,and recovered to（or close to）at the eighth week.The expression level of IL-4 reached its peak at 4 weeks and returned to（or near）the level before occlusion at the eighth week.The overall trend is to rise first and then decline.Conclusions1.It is the first time that the self-designed visual combined with pressure-sensing artificial anal plugging device was used for animal experiments in small pigs,and the feasibility and safety of the self-developed visual occluder were discussed and evaluated.2.Pressure-aware visual artificial anal occlusion device can sense the pressure in the intestinal tube in real time and observe the contents of the intestinal contents through the camera in comparison with other types of occlusion devices,and the patient can timely perform this feedback.At the same time,through animal experiments,it has been proved at the molecular level that the visual anal occluder has a milder side effect of inflammation after being used than a conventional occluder.3.The construction method of the small pig intestine stoma model is effective.At the 8th week after operation,the bowel movement at the small intestine of the small pig is normal,which can better simulate the normal bowel movement process. |
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