Feasibility Study On Artificial Anus Plugging Device Combined With Pressure Sensor

Background and objection:Colostomy is one of the most common surgical procedures available for patients with colorectal cancer (CRC), because of whose incidence rates substantially increases. Colostomy also called artificial anus, which can alternative situ anus, relieve the symptoms of various causes of fecal incontinence and constipation. There are over hundreds of thousands of patients with a sigmoid colostomy because of colorectal cancer, trauma, inflammation and congenital deformity, and stoma-related complications occur frequently creating specific care problem in psychological, physiological, society and may even cause social restrictions and have a major impact on the outcome in term of patients’ coping with their new life style, patients with colostomy may suffer incontinence and lack of control over gas and feces that the normal rectal sphincter affords, which complicated by the various types of dermatitis. Colostomy bag is the most widely used for postoperative care of patients with colostomy, which prevent the fecal contaminating peristoma skin and spreading odor, appropriately control defecation, to improve the quality of life (QoL).Fecal incontinence which is defined as continuous or recurrent uncontrolled passage of fecal material (>10mL) for at least one month in an individual older than three years of age, is the persistent or recurrent can not perceive the shape of the intestinal contents or unable to control the discharge of intestinal contents, including liquid, gaseous, solid intestinal contents, is a complex, multifactorial defecationdysfunction, damage to the ability to control gas or stool, resulting in an increase in the number of bowel movements, often diarrhea. These clinical symptoms seriously affect the patient’s daily life, and bring patients to mental stress.In recent years, people started to study a variety of artificial anus closure device, in order to simplify the operation, control defecation, and improve the quality of life. Reports have shown that artificial anus plugging device can achieve colostomy continence, however, the colostomy fecal leakage, odor, skin infection and other complications cannot eliminate completely. The current known artificial anus plugging device cannot distinguish the nature of the intestinal contents, patients do not know when to evacuate, and they have to establish a bowel habit to defecate after opening the device at regular intervals. Meanwhile, colostomy alarm device provides an apparatus and method for monitoring the presence of fecal mass in a stoma, to control defecation artificially. The volume of alarm device is too large to carry, and the occlusion effect is unknown with high incidence of fecal leakage and peristoma infection, however, the colostomy alarm device provides the possibility of intelligent artificial anus plugging device, which relevant research are not taken seriously. Here we describe an intelligent artificial anus plugging device, which consists of an artificial anus plugging device and pressure sensor, observe the occlusion effect comparison with different intestinal pressure and evaluate the feasibility of intelligent artificial anus plugging device, so as to explore the appropriate timing of the device open for further clinical studies and application provide the basis for intelligent artificial anus plugging device.Methods and materials:1. The device is made of silicone rubber, which is a traditional biomedical material with some advantages, such as good biocompatibility, heat and aging resistance, easily processed into a variety of shapes. The plugging device model consisting of an adhesive base plate surrounding the stoma skin, a disposable cylinder colostomy plug and an inflatable balloon located in the head end of the plug. The plug can be applied on colostomies up to4.0cm in diameter. The base plate apron and fixed part are taken from the two-piece colostomy bag produced by Coloplast.Application of the device is fairly simple. Once the plug is inserted into the colostomy, connected it with base plate fixed in the abdominal wall, inflate the balloon cuff with10mL of water using a20mL plastic syringe, and regulate the initial intestinal pressure. The volume of water to be introduced ranges from10-15mL according to the size of the colon. When stool enters into the colon and strike the inflated balloon, changing intestinal pressure was measured through pressure sensor in vitro.2. Computer bio-signal collection and processing system based on the computer as the core, combined with the extensible software technology, integrated of biological amplifier with electrical stimulator, and had a graphical display, data storage, data processing and analysis functions electrophysiology laboratory equipment. Hardware mainly to complete a variety of biological electrical signals, such as electrocardiogram (ECG), electromyography (EMG), electroencephalogram (EEG) and non-bio-electrical signals (such as blood pressure, tension, breathing) collection, adjust and amplificate the collected signal, then turn on signal analog/digital (A/D) conversion, and make it into the computer. Software mainly used for displaying, recording, storing, processing, and printing output the biological signal digitized, to controlling the various parts of the system at the same time, to make a dialogue with the operator.3. The pressure sensor may converted a variety of pressure change (such as arterial pressure, meridians pressure, ventricular pressure, intestinal pressure, etc.) to an electrical signal, and then the electrical signal after amplification inputted to the recording apparatus, so as to analysis the physiological changes that is in a position to represent in-depth. Pressure sensor has some advantages, such as high accuracy, good stability, high sensitivity, output signal; wide operating temperature range, security, isolation, and proof.4. All animals randomly divided into three groups to adapt to the surrounding environment three days before experiments, preoperative fasting48h and forbidden water8h, in order to avoid adverse events in anesthesia induction, such as nausea, vomiting and palpitation. All surgical procedures on mini pigs were carried out under sterile conditions. The preoperative preparation in accordance with the extraperitoneal colon colostomy establish chitterlings stoma model.Give liquid diet1-3days after surgery, and gradually transition to normal diet with closely observe animal life signs change. After general condition is stabilized, place the artificial anus plugging device with the same diameter each group, the device was placed about6-8h every day. Measured the intestinal pressure and set the pressure of opening the device each group were5mmHg,10mmHg,15mmHg. Decide whether to open the device according to the intestinal pressure measured, to achieve fecal continence.5. Perception sensitivity and stoma leakage of each group:Animals in each group set different intestinal pressure upper limit, respectively, the device were placed at postoperative1,4,8weeks, and opened when intestinal pressure reach the set value. We observed whether there have intestinal contents and repeated20times each individual, to calculate the sensitivity. Placed the device at postoperative1,4,8weeks, and observed the number of leakage within6h after the intestinal pressure reach the set value, to evaluate the occlusion effect of the plugging device.Date were expressed as mean value and standard deviation (x±s). Categorical data were calculated by nonparametric test for several independent samples (Kruskal-Wallis test) and several related sample (Friedman test). All analysis of variance were analyzed with SPSS13.0software (SPSS Incorporated, Chicago, IL, USA). A value of P<0.05was considered significant.Results:1. Perception sensitivity comparable in intestinal contents of intelligent artificial anus plugging device within different intestinal pressure:In general, the perception sensitivity with intestinal pressure has a rising trend, and when the intestinal pressure reached15mmHg, the perceived sensitivity of artificial anus plugging device combined with the pressure sensor were above90%in the postoperative period. There is no significant time effect differences in perception sensitivity among5mmHg group,10mmHg group and15mmHg group (P>0.05), postoperative1week,4weeks and8weeks, the significant difference of perceived sensitivity were observed among the groups(P<0.05). This may be due to gastrointestinal function is not fully recovered which lead to the less perception sensitivity in intestinal contents in the early postoperative period. 2. Stoma leakage comparable in intestinal contents of intelligent artificial anus plugging device within different intestinal pressure:Groups stoma leakage of colostomy are on a decreasing trend over time progress, which may be associated with the narrowing stoma diameter in postoperative period. There is a significant difference in15mmHg group among each time period leak (P=0.050), meanwhile, There is no significant time effect in5mmHg group and10mmHg groups of stoma leakage. At the same period, the stoma leak situation are positively correlated with intestinal pressure, postoperative one week among each group in stoma leakage situation difference was statistically significant (P=0.030<0.05), and4weeks and8weeks after surgery, there is no significant difference in stoma leakage situation among each group.(P=0.058>0.051>0.05)Conclusions:1. The artificial anus plugging device combined with pressure sensor for small pig anirnal studies, to observe the occlusion effect of plugging device by measuring the intestinal pressure.2. Open the artificial anus plugging device when the intestinal pressure reach10mmHg-15mmHg, pressure sensor sensing high sensitivity, meanwhile, does not influence the occlusion effect.3. The artificial anus plugging device introduced this research can be better fixed plug, and clean reusable, however, place the two-piece plugging device would easily cause intestinal stoma prolapse, and the diameter of plugging device to be based on change of intestinal stoma diameter change, which effect the blocking effect.4. The mini-pig intestinal stoma model is proven to be effective.8weeks postoperatively, mini-pig intestines colostomy is normal in defecation, which can better situlate the normal process of defecation.