| Background and objectiveIncidence rate of colorectal perforation is about 3-8% of the total number of colorectal cancer, spontaneous colon perforation in all diseases is about 1.2-4.6% including various tumors. Spontaneous colon perforation occur at opposite mesentery edge of the sigmoid colon or the junction of the sigmoid colon and rectum,the rate is more than 50% due to special physiological and anatomical factors at sigmoid colon. Spontaneous perforation of the colon happens to mainly the 60 years old persons or elders,because the case history is difficult to describe clearly,and with the lack of specific clinical manifestations of colon perforation, early diagnosis is less than 10%. Since a large number of bacteria are in colon contents, serious diffuse peritonitis happens after diagnosis, a substantial absorption of bacterial toxins,the formation of infection antibodies and lead to multiple organ failure, so the mortality can reach 35-47%.The rate of various forms colorectal anastomosis leakage(AL) is about 3-9%, TME is 2-19%, the mortality rate of AL is 12.9%, AL happens to mainly the elders and the mortality is about 35-47%.The cases of colorectal perforation or AL repair are large each year in China. The traditional treatment for these patients is taking on the principle of full-thickness interruption suture and seromuscular layer strengthened,and the colostomy in proximal colon through abdominal wall,2-3 months later the colostomy is closed and returned back to the abdomen (except cancer).This approach is characteristic of longer duration, large pain, especially the huge scar left on the abdominal wall,the complications including colon adhesion,the high cost. tremendous psychological pressure and pain due to twice surgery. How to safely and effectively simplify the treatment of this disease, shortening the course, reducing costs and seeking to a minimally invasive, beautiful and low complications surgical treatment? In recent years, minimally invasive gastrocolon surgery with laparoscopy as the main body and clinical application of artificial absorption biological material are increasing. Therefore, colon sac duct (CSD)can effectively solve the problems we face.Purpose:1 Summarizing successful experience of the previous clinical surgery for repairing colorectal perforation and AL, analyzing traditional surgical critical successive factors and shortcomings,human anus which has a natural channel leading to out-of-body and practical researchs I designed and made medical equipment-CSD that can reach the any parts of the body and effectively repair colorectal perforation and AL through the anus,furthermore tested the performance of CSD objectively to verify safety, reliability and validity for experimental and clinical application.2 Through experimental studies with Tibet mini-pig colon I verified that CSD can used as a safe and reliable new technology for repairing colorectal perforation and AL effectively,in particular when colorectal perforation or anastomosis leakage is more than 48 to 72 hours,there is severe abdominal infection. Traditional surgery as the control, and further verified if CSD has a new scientific technology, security, reliability, validity and minimally invasive advantage. Contents and methods1 CSD prototyping1.1 Making the default programMaking three preset programs, reviewing literature in preliminary experiments. About 35kg Tibet mini pig was dissected to understand its colorectal lumen diameter size as basis of the colon sac design.making CSD three preset programs, and drawing projects map and three-dimensional color pictures.1.2 Material selectionWith the help of polymer material engineers, comparing elastic modulus, tensile strength, break elongation rate of several medical grade polymer material widely used in clinic and with good tissue compatibility, I selected the silastic, polyurethane for CSD samples at last.1.3 Sample productionLooking for samples production units, according to our design that provide three-dimensional color pictures,engineering production line graph,We made the mold, repeatedly revised the mold as needed to produce the three preset CSD samples.1.4 Determine the final sampleCSD structure is as follows up:mainly with the outer capsule (1) and inner duct (2),2 circular grooves at both ends of outer capsule (3) for fixing and isolateing, there is a closed annular space between the outer capsule and the inner duct (4), with hot fusion technology to bond the two into one capsule for filling capsule with saline/gas,The inflatable duct is at one side of the capsule (5) and communicates annular space. Outer capsule texture is flexibile, inner duct texture is hard, The outer capsule contracts at both ends, extending to the inner duct wall. This design model can be used for repairing colorectal perforation or AL in 1st stage, which can block the pressure of the perforation or leakage passing the wound, the wound can also completely isolated from the colon contents.These is good for healing.1.5 sample performance testThe CSD,inflatable duct and precision pressure gauges were connected by three-way duct,then aerateed to observe if the CSD and inner duct were deformed,circular grooves were convex, sac leaked or broke,at the same time recording the pressure readings on pressure gauge.2 CSD repairing colon perforation and AL in animal experiments2.1 Experimental DesignTibet mini-pigs were randomly divided into 2 groups, treatment group and control group,15 per group, repairing colon AL of treatment group with CSD, the control group with traditional suture and colostomy in a proximal colon in 1st stage,then put colostomy back in 2nd stage.Comparing operation time, postoperative abdominal adhesions,safety,reliability, validity.at the at 7th,14th,21st days later,detecting the anastomotic leak condition:Comparing of the healing of AL intensity:burst pressure, the tissue micro vessel density(MVD) and hydroxyproline contents in healing parts, assessing practicality, reliability, security, and minimally invasive effects of CSD repairing colorectal perforation and AL.2.2 Making animal modelAnimal models were made under the surveillance of laparoscopic transanal using experimental Tibet mini-pigs, weight 30-50kg. anesthesia wtih Ketamine combined with pentobarbital. Weighing before anesthesia, intramuscular injection luminal sodium 100mg, atropine 0.5mg at the hip. Anesthesia was induced by injection of ketamine 6mg/kg by ears, when the pig became quiet, endotracheal was dealed (No.7.0) and fixed. Maintaining pentobarbital or propofol by intravenous infusion during surgery. Connecting lines and piping, opening the cold light, modulating laparoscope, CO2 pneumoperitoneum machines, high frequency electroscalpel, laparoscopic black and white and clarity adjustment. Conventional establishment of pneumoperitoneum at upper-right navel, when intra-abdominal pressure reached 10-12mmHg state, the 10mmTrocar puncture, laparoscopic vision duct were placed, observing the organs in the abdominal cavity to exclude intra-abdominal abnormalities. Inserting vision duct, from the anus,under the supervision of the laparoscope arriving about 25-30cm from the anus, at the opposite edge of mesenteric piercing the colon wall, formating about 1.0×1.2cm perforation, then colon perforation model was made. About 25-30cm from the anus at the colon, cutting off the colon with electric coagulation hook then suturing the two ends of colon with silk, but 1/3 circle colon was left for non-closure at contralateral margin of mesenterium, then colon AL model was made.2.3 Application of CSD for the colon perforation or AL in repairing in 1st stage.Re-operation at 48 hours after the first surgery, in the application of laparoscope repairing the leakage and perforation with CSD. Anesthesia, position and disinfection, sterile towel were the same foregoing. Through original suture incision separating the abdominal wall layers gradually with curved forceps, entering the abdominal cavity, there was attention to prevent colon injury due to adhesion, Inserting lmm Trocar into the abdominal cavity, and placing 10mm vison duct, carefully observing the intra-abdominal adhesions, avoid damaging colon. At proper position in the left and right lower abdomen under laparoscopic monitoring cutting a incision about 5mm, and implanting 5mm Trocar and the corresponding laparoscopic instruments. Separating intra-abdominal adhesions and clearing the pus and abdominal stool left gently, looking for perforation or leak. If you had difficulty in finding them, rinsing gently with warm water and sucking carefully. After finding perforation or leakage,longitudinally seaming with code 4 thread and circular needle, hanging, cutting a small abnormal tissue for pathology. Another members expanding the anal with fingers gently and gradually to 2 finger width, then inserting the anal speculum, washing the colon with a large number of diluted povidone-iodine,Lubricating CSD and colon lumen with paraffin oil, then under laparoscopic surveillance pushing the sac duct to the place of perforation or leakage with pushing device, making sure that the perforation or leakage was in center of the sac duct, inflating with aeration the sac duct to make it tough, but not too hard, avoiding expanding and oppressing bowel, causing too large bowel wall tension, effecting lesion revascularization. The sac duct in the colon lumen duct had a certain activity. Inserting metal rod into the pushing device, the device is similar to the lift-uterus device in obstetrics and gynecology, making perforation part of the colon and its mesentery swing up and down, and a certain tension with the auxiliary,clearly revealing the avascular zone, which will help surgery operation. With the separation clamp permeating the mesocolon avascular zone on the two circular groove location of the sac duct close the colon wall, not damage the colon blood flow, fixing colon in the sac duct moderately with absorbable catgut,making the parts of the colon perforation or leakage isolate from the colon lumen completely, rinsing the peritoneal cavity with a large number of warm salt water, careful hemostasis, inventorying gauzes equipment, exhausting pneumoperitoneum, removing equipment, closing the incision, fixing the aeration duct. After 1 hour, anesthesia disappeared, giving the pig drinking water and no residue liquid diet after fasting 24 hours.Control group of traditional surgery:anesthesia, fixing position, disinfection, posing towels, opening the abdomen from the original incision,explorating perforation site, full-thickness sutures.making a round incision with diameter about 3.0cm at about 5.0cm front left side of the incision,opening the subcutaneous tissue, fascia with electroscalpel, bluntly separating the abdominal muscles, cutting peritoneum, taking out the suitable colon section through the stoma, making the plastic sticks and rubber ducts across the mesenteric vascular-free zone to fixed the colon on the abdominal wall, making a 3.0cm longitudinal incision on the edge of the colon wall with electroscalpel, suturing the cut colon wall onto the stoma. washing abdominal cavity, careful hemostasis, remaining peritoneal drainage duct, gauze inventorying equipment, closing the abdomen and ending surgery.2.4 The third times surgery for detecting the effect of repairingDetecting the effect of repairing colon perforation and AL in treatment and control groups at the 7th,14th,21st days after surgery,detecting intra-abdominal adhesions and stenosis at AL with laparoscope, detecting the bursting pressure at AL, and take healing tissue samples for detecting hydroxyproline contents and MVD.2.4.1 Detecting bursting pressure at healed AL or perforation of the colon in vivoDetecting the location of CSD, ligating the colon with a braided belt about 5.0cm at its proximal, exhausting gas in CSD, removing it, inserting connection duct of the precision pressure gauge through the anus into the rectum 15.0-20.0cm, suturing anus with 7.0 silk to ensure that no gas permeated and the part of perforation or anastomotic leak of the colon and the pressure gauge was the same level, slowly injecting gas into the colon, the assistant closely observed and recorded pressure gauge readings, When the colon perforation or anastomotic leak site began leak, the readings was the burst pressure.Excising tissue at healed place of colon, divided them into 5 copies.1 copy was soaked in 10% formalin for HE staining, and the remaining 4 copies were stored in-80℃freezer, respectively for detecting hydroxyproline contents and MVD.2.4.2 Detecting hydroxyproline content of healed tissue of AL or perforation Alkaline lysis method of the hydroxyproline assay test box:Weighing wet weight tissue, accuratly adding alkaline lysis buffer, adjust PH value, adding activated carbon in the hydrolyzate,taking out supernatant,adding reagents,water bath,cooling, centrifuged,taking out supernatant,measureing absorbance,calculating hydroxyproline contents according to a formula.2.4.3 Detecting the MVD at healed tissue of AL or perforationEmbedding tissue sections with OCT, fixing with acetone, regular hydration, PBS wash to remove endogenous peroxidase activity,blocking with goat serum,incubating at room temperature, tilting the serum, dropping working solution with the first antibody, washing with PBS,dropping biotinylated goat anti-mouse IgG, washing with PBS, dropping streptavidin labeled with horseradish, washing with PBS, configuration DAB working solution, dropping (DAB) color reagent, washing with tap water, restaining the organization with hematoxylin, washing with PBS, dehydration, dry glass slides were mounted with neutral resin, counting microvessel.2.5 Statistical analysisStatistical analysis with software package SPSS 13.0, measurement data displayed with mean±standard deviation (x±s), comparison between two groups with two independent sample t-test (bilateral) analysis, P<0.05 as significant difference.Results1 Testing sample performance1.1 Comparing deformation pressure of outer capsule of CSDThe outer capsule deformation pressure values of CSD made of medical silastic and polyurethane were 30.42±0.46Kpa versus 30.73±0.29 Kpa,The results showed that medical polyurethane was slightly better than the medical silastic, but no statistical difference 1.2 Comparing deformation pressure of inner duct of CSDThe inner duct deformation pressure values of CSD made of medical silastic and polyurethane were 5.96±0.22 Kpa and>100 Kpa, the CSD made of medical silastic was not enough hard, easily lead to stenosis and closure.but the inner duct of CSD made of medical polyurethane do not deform When the pressure value is more than 100 Kpa. So the CSD made of medical polyurethane is better than that made of medical silastic.1.3 Comparing leak pressure of CSDThe leakage gas pressure values of CSD made of medical silastic and polyurethane were 59.23±1.25 Kpa versus 60.01±1.45 Kpa, medical polyurethane was slightly better than the medical silastic, but no statistical difference.2 Testing the healing parts of colon perforation2.1 Measuring the bursting pressure after colon perforation repairedThe 7th,14th,21st days after surgery, bursting pressure in the treatment group and control group:26.20+2.76,36.12+1.67,38.58+1.46 versus 21.28+0.80,27.72±1.07,35.92+2.01. The bursting pressure in treatment groups was higher than that of the control group at 7th,14th,21st days after surgery (t=3.83,P=0.005;t=9.46,P <0.001;t=2.39,P=0.044)2.2 Measuring the hydroxyproline contents in the healing site after colon perforation repairedThe 7th,14th,21st days after surgery, the hydroxyproline contents in the treatment group and control group:21.42±0.76,25.96±0.87,27.50±0.59 versus 15.14±0.97,21.08±1.08,26.90±0.56, It was higher in treatment group than that of the control group at 7th,14th days after surgery (t=11.39;t=7.82,P<0.001),no significant difference between 2 groups at 21st day (t=1.65,P=0.139)2.3 Measuring the MVD in the healing site after colon perforation repaired The 7th day after surgery,the MVD in the treatment group and control group:12.40+0.89 versus 10.40+1.14.It was higher in treatment group than that of the control group at the 7th after surgery (t=3.09,P=0.015)3 Testing the healing parts of AL3.1 Measuring the bursting pressure after colon AL repairedThe 7th,14th,21st days after surgery, the bursting pressure in the treatment group and control group:23.54+1.41,34.14±1.86,36.70±1.52 versus 19.10±0.57,25.96±1.17,34.00±2.15. The bursting pressure in treatment groups is higher than that of the control group at the 7th,14th days after surgery (t=6.54, P<0.001;t=8.31,P<0.001), No significant difference between 2 groups at 21st day(t=2.29,P=0.051).3.2 Measuring the hydroxyproline contents in the healing site after colon AL repaired.The 7th,14th,21st days after surgery,hydroxyproline contents in the treatment group and control group:20.46±0.76,25.08±1.07,26.10±0.61 versus 14.20±0.94, 20.22±1.22,26.70±0.67, It was higher in treatment group than that of the control group at 7th,14th days after surgery(t=0.41,P<0.001;t=0.82,P<0.001), no significant difference between 2 groups at 21st day(t=0.85, P=0.179).3.3 Measuring the MVD in the healing site of AL repairedThe 7th day after surgery, MVD in the treatment group and control group:11.20±0.84 versus 8.80±0.84. It was higher in treatment group than that of the control group at 7th day after surgery (t=4.54,P=0.002).Conclusion1. The CSD made of polyurethane has simple structure, excellent performance, easy operation, safety, reliability,so has clinical value.2. Repairing colon AL or perforation with the CSD in 1st stage is safe, reliable and effective. The innovation1 The CSD can reach every place of colorectal through the anus, repair colorectal perforation and AL with laparoscope in 1st stage.2 Treatment effect of CSD is safe, reliable, and can effectively replace the traditional surgery-repair and stoma in 1st stage, put back the colon in 2nd stage. |
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