Biological patch for digestive surgery and preparation method therefor

Abstract

Disclosed is a biological patch for digestive surgery. The biological patch has a maximum tensile elongation of no less than 14.8%, an elastic deformation rate range of no less than 13.7%, and a single-thread suture pulling force of greater than 15.6 N. Also disclosed is a preparation method for the biological patch. The biological patch provided by the present invention can effectively reduce the incidence of complications of digestive surgery, such as anastomotic bleeding and liquid leakage, thereby simplifying surgical operations.

Description

A biological patch for digestive surgery and its preparation method Technical Field

[0001] This invention relates to a biological patch for digestive surgery and its preparation method. Background Technology

[0002] Gastrointestinal tumors refer to a broad category of benign and malignant tumors originating in the digestive tract. With the increasing aging population, the proportion of patients with digestive tumors is gradually rising. These patients often experience poor tissue quality after radiotherapy and chemotherapy, making them prone to complications such as margin bleeding, oozing, and anastomotic stricture at the anastomosis site (the area where the stomach or esophagus and small intestine are sutured together). These complications significantly increase the patient's mental, physical, and financial burden. In the field of digestive surgery, due to the numerous blood vessels involved, the most common complications are bleeding or oozing during the intraoperative and postoperative stages. Managing intraoperative bleeding or oozing prolongs the operation, causes greater patient trauma, and requires more medical supplies and instruments. Postoperative bleeding necessitates longer hospitalizations and may even require a second surgery.

[0003] To address these complications, minimally invasive surgery has become increasingly popular, with anastomotic devices being a commonly used surgical tool. While minimally invasive surgery reduces surgical trauma to some extent, anastomotic complications still exist. Biomaterial-based patches offer excellent elasticity and can tighten the anastomosis, reducing the incidence of complications such as anastomotic bleeding or stenosis. Therefore, clinical practice has begun to explore methods of reinforcing the anastomosis with biomaterial patches to reduce surgical difficulty, intraoperative and postoperative complications, and improve treatment outcomes. Summary of the Invention

[0004] This invention has found that by controlling the range of four key parameters—maximum tensile elongation, elastic deformation rate, single-line suture traction force, and the value of elastic deformation rate relative to maximum tensile elongation—the resulting biological patch can effectively reduce intraoperative or postoperative complications such as anastomotic bleeding and gastric and intestinal fluid leakage during digestive surgery.

[0005] In this invention, the determination of maximum tensile elongation and single-line suture tensile force refers to existing literature (Li Chongchong, Liu Li, Wang Shuo, et al. Comparison of mechanical properties of allogeneic and animal-derived patches [J]. Beijing Biomedical Engineering, 2021.). The elastic deformation rate is determined using conventional methods in the field. The prepared biological patch is cut to a length of 4 cm and a width of 1 cm. The biological patch is clamped on a tensile testing machine along its length and a tensile load is applied at a speed of 100 mm / min to stretch the biological patch until it breaks. A tensile curve is plotted, and the elastic deformation rate of the biological patch is calculated based on the elastic deformation segment of the tensile curve.

[0006] As one aspect of the present invention, a digestive surgical biological patch is provided, wherein the biological patch has a maximum tensile elongation of not less than 14.8%, an elastic deformation rate of not less than 13.7%, and a single-line suture traction force greater than 15.6N.

[0007] In a specific embodiment, the biological patch has a maximum tensile elongation of 14.8-44.6%, an elastic deformation rate of 13.7-39.1%, a single-line suture traction force of 15.6-54.1 N, and an elastic deformation rate accounting for 39-89% of the maximum tensile elongation. It is suitable for surgical procedures involving the colon and ileum of the digestive tract.

[0008] In a specific embodiment, the biological patch has a maximum tensile elongation of 14.8-44.6%, an elastic deformation rate of 14.6-39.1%, a single-suture traction force of 15.6-54.1 N, and an elastic deformation rate accounting for 50-89% of the maximum tensile elongation. It is suitable for surgical procedures in the digestive tract and rectum.

[0009] In a specific embodiment, the biological patch has a maximum tensile elongation of 14.8-44.6%, an elastic deformation rate of 13.7-39.1%, a single-suture traction force of 15.6-54.1 N, and an elastic deformation rate accounting for 50-89% of the maximum tensile elongation. It is suitable for surgical procedures involving the duodenum in the digestive tract.

[0010] In a specific embodiment, the biological patch has a maximum tensile elongation of 14.8-44.6%, an elastic deformation rate of 14.6-39.1%, a single-line suture traction force of 19.7-54.1 N, and an elastic deformation rate accounting for 56-89% of the maximum tensile elongation. It is suitable for surgical procedures on the stomach of the digestive tract and can also be widely applied to surgical procedures on other parts of the digestive tract.

[0011] The preferred digestive surgical biological patch is a biological patch derived from bovine pericardium.

[0012] The digestive surgical biological patch has two perforations located at opposite ends of the biological patch.

[0013] As another aspect of the invention, it relates to an anastomosis device kit including the aforementioned digestive surgical biological patch. Since most digestive surgical cuts currently employ an anastomosis device, the application of the patch requires pre-installation of the anastomosis device clips, i.e., the patch is stretched and fixed to both ends of the clips before surgery.

[0014] As another aspect of the present invention, a method for preparing the above-mentioned digestive surgical biological patch is provided, comprising the following steps:

[0015] (1) Immerse healthy bovine pericardial tissue in hypotonic Hank's solution, and rinse and replace the hypotonic Hank's solution repeatedly to fully swell and break down the various cells present in the tissue;

[0016] (2) Rinse the tissue slides treated above repeatedly with physiological saline for 60-120 minutes each time, and change the physiological saline each time. The total number of rinsing times depends on whether there are no shaped cells or cell components and cell debris under the microscope of the tissue slides. Perform quantitative determination of protein and nucleic acid until no soluble protein and nucleic acid can be detected.

[0017] (3) Use the surfactant solution Tween 80 to remove phospholipids and non-structural proteins, as well as some tissue matrix molecules such as hyaluronic acid, various chondroitin sulfates and mucopolysaccharides from the tissue slices.

[0018] (4) Soak in a 0.5-1.5% glutaraldehyde solution for 3-3.5 hours;

[0019] (5) Place the pretreated tissue material in Cr 3+ The ion concentration is 0.0625 mol / dm³. 3 In a hydroxychromium solution with an OH / Cr ratio of 0.5, the solution was shaken in a water bath at 35-42℃ for 3.5-5 hours. The pH of the solution was measured and increased by 0.3-0.5 pH units with 10% NaHCO3, and then shaken in a water bath at 40-46℃ for 60 minutes.

[0020] The biological patch provided by this invention serves as a liner for the surgical margins of gastric and intestinal digestive tract tissues. Before surgery, it can be easily and stably pre-placed inside the clamping plate of the stapler. During the surgical clamping of tissues, the staple holes and sutures formed after the titanium staples of the stapler pass through the biological patch will quickly shrink due to the elastic recoil deformation of the biological patch to prevent leakage. At the same time, the elastic deformation of the biological patch also makes the tissue clamping more stable and reliable, playing a role in sealing and promoting the healing and repair of the surgical margin tissues. It can effectively prevent various complications such as esophageal leakage, gastric leakage, and intestinal leakage caused by postoperative bleeding and exudation.

[0021] The biological patch provided by this invention uses bovine pericardium as raw material, has excellent tissue compatibility, can promote tissue repair and healing, and can evenly distribute the stress of titanium nail compression on the entire anastomotic suture nail, reducing local tissue cutting force, effectively reducing the incidence of complications such as anastomotic bleeding and exudation, and simplifying surgical procedures. Attached Figure Description

[0022] Figure 1 is a schematic diagram of a biological patch pre-placed on an anastomosis device; where A represents biological patches with different perforation distances; B represents an anastomosis device without a pre-placed biological patch; C represents a biological patch with a pre-placed anastomosis device; and D is a magnified view of part E in Figure C.

[0023] Figure 2 shows the HE staining results of the pig heart, liver, spleen and lungs using the biological patch obtained in Example 1.

[0024] Figure 3 shows the HE staining results of the left and right kidneys and brain of white pigs using the biological patch obtained in Example 1.

[0025] Figure 4 shows the HE staining results of the pig stomach, perigastric tissue and intestine using the biological patch obtained in Example 1.

[0026] Figure 5 shows the HE staining results of the white pig intestinal peritoneum tissue obtained using the biological patch obtained in Example 1.

[0027] Figure labels: 1. Biological patch; 2. Perforation device; 3. Clamping piece; 4. Staple cartridge or titanium anvil; 5. Detailed Implementation

[0028] In developing this invention, the inventors first addressed the common complications of anastomotic bleeding and exudation during digestive surgery. Referring to existing literature (Li Chongchong, Liu Li, Wang Shuo, et al. Comparison of mechanical properties of allogeneic and animal-derived patches [J]. Beijing Biomedical Engineering, 2021.), they used tensile strength, maximum elongation, and single-suture traction force of biological patches as parameters for screening them, with the measurement methods for each parameter also referenced in that literature. However, after measurement, it was found that the tensile strength of the obtained biological patches fluctuated significantly and was unstable. Furthermore, animal experiments revealed that the correlation between the tensile strength of biological patches and anastomotic bleeding and exudation was unstable, and the tensile strength of biological patches could not be used as a parameter for screening them. Therefore, the inventors determined the maximum elongation, elastic deformation rate, and single-suture traction force as the screening and evaluation parameters for biological patches, and determined the optimal ranges for these three parameters through clinical trials as follows:

[0029] (1) Biological patches for colon and ileum surgery: maximum tensile elongation range 14.8-44.6%, elastic deformation range 13.7-39.1%, single suture traction force 15.6-54.1N.

[0030] (2) Biological patches for rectal surgery: maximum tensile elongation range 14.8-44.6%, elastic deformation range 14.6-39.1%, and single-line suture traction force 15.6-54.1N.

[0031] (3) Biological patches for duodenal surgery: maximum tensile elongation range 14.8-44.6%, elastic deformation range 13.7-39.1%, and single-line suture traction force 15.6-54.1N.

[0032] (4) Biological patches for gastric surgery and biological patches for general digestive surgery: maximum tensile elongation range 14.8-44.6%, elastic deformation range 14.6-39.1%, and single-line suture traction force 19.7-54.1N.

[0033] However, during this process, it was unexpectedly discovered that the ratio of elastic deformation rate to maximum tensile elongation also affects anastomotic bleeding and exudation.

[0034] The inventors further validated this finding through clinical trials, confirming that when the maximum tensile elongation, elastic deformation rate, and single-suture traction force are within specific ranges, controlling the elastic deformation rate as a percentage of the maximum tensile elongation helps reduce complications such as anastomotic bleeding and exudation in digestive surgery. The required elastic deformation rate as a percentage of the maximum tensile elongation for different surgical sites is as follows:

[0035] (1) Biological patches for colon and ileum surgery: elastic deformation rate accounts for 39-89% of the maximum tensile elongation.

[0036] (2) Biological patches for rectal and duodenal surgery: elastic deformation rate accounts for 50-89% of the maximum tensile elongation.

[0037] (3) Biological patches for gastric surgery and biological patches for general digestive surgery: elastic deformation rate accounts for 56-89% of the maximum tensile elongation.

[0038] I. Preparation method of biological patch

[0039] (1) Preprocessing

[0040] In this invention, the pretreatment specifically refers to the decellularization and immunogenicity removal procedures on biological tissues, which are conventional techniques in the field aimed at removing cellular tissue components and eliminating immunogenicity. This invention does not limit the specific operational process. The specific operational process can be found as follows:

[0041] ① Healthy bovine pericardial tissue sheets were immersed in hypotonic Hank's solution, and the solution was repeatedly changed and rinsed to fully swell and break down the various cells present in the tissue. This invention uses bovine pericardial tissue.

[0042] ② Rinse the tissue slides treated above repeatedly with physiological saline for 60-120 minutes each time (for example, in a specific embodiment of the present invention, the preferred rinsing time with physiological saline is 60 minutes). Change the physiological saline each time. The total number of rinsing times depends on whether there are no tangible cells or cell components and cell debris under the microscope of the tissue slide. Perform quantitative determination of protein and nucleic acid until no soluble protein and nucleic acid can be detected.

[0043] ③ Use the surfactant solution Tween 80 to remove phospholipids and non-structural proteins, as well as some tissue matrix molecules such as hyaluronic acid, various chondroitin sulfates, and mucopolysaccharides from the tissue slices.

[0044] ④ Soak in a 0.5-1.5% glutaraldehyde solution for 3-3.5 hours. In a specific embodiment of the present invention, the preferred glutaraldehyde soaking conditions are: 3.5 hours in a 0.5% glutaraldehyde solution.

[0045] (2) Chemical modification

[0046] This invention involves cross-linking and modifying free carboxyl groups within and / or between collagen molecules and between collagen and the tissue matrix to impart corresponding mechanical and anti-calcification properties to the modified tissue sheet. The cross-linking agent used in this invention is a polymer of a coordination compound of hydroxychromium. Specific procedures can be found by placing the pretreated tissue material in a Cr... 3+ The ion concentration is 0.0625 mol / dm³. 3 The material is first shaken in a hydroxychromium solution with an OH / Cr ratio of 0.5 in a water bath at 35-42°C for 3.5-5 hours (for example, in a specific embodiment of the present invention, the first water bath shaking condition is 35°C for 3.5 hours). The pH of the material treatment solution is measured and increased by 0.3-0.5 pH units using 10% NaHCO3 (for example, in a specific embodiment of the present invention, it is preferred to increase the pH by 0.3 pH units using 10% NaHCO3). Then, a second water bath shaking is performed at 40-46°C for 60-120 minutes (for example, in a specific embodiment of the present invention, the first water bath shaking condition is preferred to be 40°C for 60 minutes). Finally, a single-layer sheet-like biological patch is obtained.

[0047] The resulting biological patch has a rough surface on one side and a smooth surface on the other. As shown in Figure 1, two or more perforations 2, slightly smaller than the width of the clamping piece 4, are made on the resulting biological patch 1, with the perforations 2 having the same direction and a size slightly smaller than the width of the clamping piece 4. The free end of the clamping piece 4 passes through two of the perforations 2 in sequence (the distance between the two perforations 2 is selected according to the surgical needs). The position of the biological patch 1 is further adjusted manually so that the biological patch 1 is laid flat and adheres to the inner side of the clamping piece 4. The rough surface contacts the staple cartridge or anvil 5 of the stapler, and after contact, there is a large friction force, making it difficult for the biological patch 1 to slip off during cutting and anastomosis by the stapler 3. The smooth surface adheres to the digestive tissue, ensuring the degree of adhesion with the digestive tissue. The perforation 2 being slightly smaller than the width of the clamping piece 4 ensures that the biological patch 1 remains in a stretched state when it is hung on the clamping piece 4, preventing it from sliding or slipping off the clamping piece 4.

[0048] Examples 1-17

[0049] Table 1: Main differences in the preparation methods of Examples 1-17

[0050] II. Determination of tensile strength, maximum tensile elongation, and single-thread suture tension.

[0051] Good mechanical properties can reduce the incidence of complications such as anastomotic bleeding and exudation, improve the compliance of biological patches, and enhance patient comfort. To explore the relationship between mechanical parameters and bleeding, exudation, compliance, and comfort of gastroenterology biological patches, the inventors first reviewed the literature and, based on existing literature (Li Chongchong, Liu Li, Wang Shuo, et al. Comparison of mechanical properties of allogeneic and animal-derived patches [J]. Beijing Biomedical Engineering, 2021.), measured the biological patches obtained in Examples 1-17.

[0052] This invention prepared 17 batches of biological patches through Examples 1-17, with 10 biological patches obtained from each batch (example). The parameters were measured according to the aforementioned literature, and the average values ​​were taken. The tensile strength, maximum tensile elongation, and single-line suture traction force of the obtained biological patches are shown in Table 2 below.

[0053] Table 2: Maximum tensile elongation, tensile strength and single-thread suture pull force of Examples 1-17

[0054] As can be seen from Table 2, the tensile strength of the 10 biological patches obtained in the same batch in each of Examples 1-17 fluctuated greatly and the values ​​were unstable. This may be because there are other influencing factors on the tensile strength of the patches that the inventors have not discovered, making it impossible to accurately control the tensile strength of the biological patches, which is not suitable for use as surgical materials.

[0055] Based on the mechanical parameters obtained by the above preparation methods, the maximum tensile elongation of the biological patch obtained by the present invention ranges from 11.1% to 44.6%, the tensile strength from 20.3% to 37.5 MPa, and the single-line suture traction force ranges from 15.6% to 54.1 N.

[0056] Ten biological patches obtained in each embodiment were cut to a length of 4cm and a width of 1cm, and tested to see if they could be pre-placed on the anastomosis device.

[0057] When a biological patch is pre-placed onto an anastomosis device, it needs to be stretched appropriately, which is related to the maximum tensile elongation. Theoretically, the higher the maximum tensile elongation, the better. If the maximum tensile elongation is too small, the biological patch will break after being stretched a small distance. For example, when 10 biological patches obtained in Example 17 (maximum tensile elongation 11.1 ± 0.4%) were assembled into an anastomosis device, it was found that 9 of them broke and 1 showed obvious cracks. This demonstrates the toughness of the biological patch, which is extremely difficult to deform, and after deformation, it quickly enters permanent deformation and rapidly breaks and fails.

[0058] It was thus found that the biological patch with a maximum tensile elongation of 11.1% did not meet the requirements for installation on a stapler. Also, based on the biological patches obtained from other embodiments that met the tensile requirements and could be pre-set on the stapler, the maximum tensile elongation of the patch obtained from Example 2, which was 14.8 ± 0.5%, was taken as the minimum value of the maximum tensile elongation that met the requirement for installing the biological patch on the stapler.

[0059] Animal experiments were conducted on the embodiments (Embodiments 1 - 16) that met the requirements for pre-setting on the stapler.

[0060] III. Animal Experiments

[0061] Since there are many similarities in the anatomical structure and physiological functions of the gastrointestinal tract between white pigs and humans, this makes white pigs an ideal animal model for studying human gastrointestinal diseases and injuries. Also, the body size of white pigs is moderate, which is convenient for experimental operation and management. Compared with small animals such as mice and rats, white pigs provide a larger operation space, enabling researchers to perform surgical operations more easily. At the same time, white pigs are easy to raise and manage under laboratory conditions, are not prone to infection after surgery, are relatively easy to control during long-term feeding, and have a high long-term survival rate.

[0062] Healthy experimental animals were purchased according to the SOP-5 Experimental Animal and Receiving Operating Procedures. The experimental animals were provided by Jiangxi Yinshe Biotechnology Co., Ltd. (License No.: SCXK(Gan)2023 - 0002), and all animals were used for animal experiments for the first time at the beginning of the experiment. All受试 animals were quarantined in isolation before surgery, and only the受试 animals that passed the isolation quarantine were included in this study.

[0063] 1. Inclusion Criteria

[0064] Meet the requirements of the national "Administrative Measures for Animal Quarantine"; body weight is between 50 - 60 kg; all physiological indicators are normal; there are no obvious serious animal diseases (such as: active peptic diseases, blood system and metabolic system diseases, infectious diseases, and zoonotic diseases, etc.).

[0065] 2. Feeding

[0066] The experimental animals were tracked and managed according to the SMP-5 Experimental Animal Care and Management Regulations. The experimental animals were given an appropriate amount of feed twice a day, and the animals could drink water freely through an automatic water supply system. The feed and water were both clean and safe.

[0067] 3. Grouping and Quantity

[0068] 1-month group: A total of 48 animals (16 embodiments, 3 animals were used for each embodiment for the experiment); 3-month group: 48 animals (16 embodiments, 3 animals were used for each embodiment for the experiment). Gender was not limited, and the animals were randomly grouped.

[0069] Animal information was recorded during the experiment, including weight, surgery time, survival days, and biological patch information.

[0070] Preoperative blood routine, blood biochemistry, coagulation function, and blood gas were measured.

[0071] Measurements were taken 1 month and 3 months post-surgery, including complete blood count, blood biochemistry, coagulation function, and blood gas analysis.

[0072] 4. Experimental Procedure

[0073] ① Preoperative preparation;

[0074] ② Perform preoperative blood tests according to routine examination requirements and record the preoperative data;

[0075] ③ During the surgery, the experimental pigs were subjected to general anesthesia, endotracheal intubation, mechanical ventilation, and disinfection and skin preparation.

[0076] ④ With the patient in a supine position, open the abdomen to expose it, free the stomach tissue, and select a suitable location; make an incision smaller than the size of the biological patch; as shown in Figure 2, attach a 1cm × 4cm biological patch to the stapler, place the stapler with the pre-placed biological patch in the predetermined position, and adjust its angle and depth to ensure close adhesion to the surrounding tissue. Carefully examine the gastric anastomosis and patch, observing whether the biological patch and digestive tissue are well anastomosed, whether the resilience of the biological patch meets the requirements, whether the biological patch is stably fixed, and whether there is bleeding or exudation at the staple holes and sutures.

[0077] ⑦ After freeing the small intestine in the abdominal cavity, select a suitable location and make an incision smaller than the patch size. Attach a 1cm × 4cm biological patch to the stapler. Place the stapler with the pre-placed biological patch in the predetermined position and adjust its angle and depth to ensure close adhesion to surrounding tissues. ⑧ Carefully examine the intestinal anastomosis and patch, observing whether the biological patch and digestive tissue are well-analyzed, whether the resilience of the biological patch meets requirements, whether the biological patch is stably fixed, and whether there is bleeding at the pin holes and suture needle holes. ⑨ After the surgery, check the anastomosis again for bleeding, exudate, etc. After confirming that everything is in order, close the abdomen.

[0078] After surgery, the test animals were transferred to the observation room for observation and were supported by ventilators until they regained consciousness and could stand and move. They were then transferred to the animal house for rearing. Alternating 12-hour / 12-hour lighting was provided daily, and the animals were given appropriate amounts of feed once in the morning and once in the afternoon, with free access to water. Their mental state, appetite, respiration, wound complications, and other adverse symptoms were observed daily.

[0079] Postoperative care includes continuous intramuscular injection of ceftriaxone sodium 2g for one week to combat infection. Daily observation of the animal's mental state, appetite, respiration, wound healing progress, and any signs of nausea, vomiting, or other gastrointestinal symptoms is crucial. The surgical wound should be disinfected with povidone-iodine until healed. Regular veterinary examinations and blood tests should be conducted, and anti-infection prevention and treatment measures should be implemented based on the results. Postoperative medication administration and adverse events (including death and infection) within 24 hours should be recorded.

[0080] Gross tissues (heart, liver, spleen, lung, kidney, brain), stomach patch and surrounding tissues, and intestinal patch and surrounding tissues of the experimental animals that reached the endpoint were taken for macroscopic observation and photography. The tissues were then fixed in 10% formalin for 48 hours, sectioned routinely, and stained with hematoxylin and eosin (HE).

[0081] The patch was visually inspected to check for completeness, defects, and leaks. The surface was checked for thrombi, and the surrounding tissues were examined for changes such as bleeding and necrosis. The test animals were euthanized 1 and 3 months after the operation, and the pathological results of the test animals that reached the endpoint were recorded.

[0082] Table 4: Pathological Scoring Principles

[0083] 5. Experimental Results

[0084] (1) No bleeding or effusion at the gastric and intestinal anastomoses occurred in pigs using the biological patches obtained in 11 examples, namely Examples 1, 5, 7-9, and 11-16.

[0085] All experimental pigs in the above experimental groups successfully underwent gastrointestinal anastomosis surgery. The biological patch adhered tightly to the anastomosis, and bleeding at the anastomosis site and surrounding tissues was effectively controlled in a timely manner. No instrument malfunctions occurred during the operation, including with the anastomosis device or its components. Anesthesia and gastrointestinal anastomosis were performed smoothly, with no bleeding or exudation at the anastomosis site. Vital signs were normal, and no adverse events occurred.

[0086] During the period of survival and rearing, the animals were generally in good condition, with normal body temperature, diet and excretion, good independent activity, and no obvious abnormalities such as weight loss, fever, anorexia, or mania. They survived to the end without complications such as bleeding, infection, anastomotic stenosis, rejection, or organ failure.

[0087] After dissection, the thoracic cavity was intact, with no pleural effusion, and no obvious pathological changes were found in the chest wall and thoracic cavity contents; the abdominal cavity was intact, with no ascites, and no obvious abnormal pathological changes were found in the abdominal wall, peritoneum, abdominal cavity contents, intestines, etc.; no changes related to the biological patch surgery were found in the specimens of the heart, liver, spleen, lungs, kidneys, brain, stomach, and intestines by gross examination.

[0088] Electrolytes, liver and kidney function tests were almost entirely within the normal range during follow-up periods following cardiac radiofrequency ablation. The coagulation INR was approximately 1.0 both preoperatively and during follow-up. Complete blood cell count, morphology, and quality were normal. White blood cell, red blood cell, hemoglobin, and platelet counts showed overall stability with no significant abnormalities in any major blood routine indicators. No abnormalities were found in liver or kidney function; some values ​​were slightly above or below the reference range, but these were not clinically significant. Laboratory results without abnormalities before the procedure and before the endpoint were considered clinically significant.

[0089] Intraoperative anatomical comparison analysis of gastrointestinal anastomoses revealed that the anastomoses between the stomach and intestines were smooth and without bleeding or exudate. At the follow-up endpoints of 1 and 3 months, the biological patch on the surface of the gastric anastomosis formed scar tissue to prevent leakage and promote healing, and was not decomposed. In the small intestine, due to the flow of food and digestive juices, the biological patch was more susceptible to physical and chemical effects, thus accelerating the degradation process. When the biological patch was implanted into the small intestinal anastomosis, it acted as a scaffold, and the degraded material could be absorbed or replaced by newly formed cells, thereby promoting complete healing of the anastomosis. This indicates that the biological patch can achieve slow decomposition and regeneration at the anastomosis site of the small intestine in the test pigs, mainly due to the interaction between its material properties and the physiological environment of the tissue. However, at the anastomosis site on the surface of the stomach, due to the different physiological environment compared to the small intestine and the interaction of the biological patch with gastric acid and pepsin, the biological patch may not decompose or decomposes at a slower rate, demonstrating the good biocompatibility of digestive surgical biological patches and their ability to form a good bond with surrounding tissues.

[0090] Figure 2 shows the HE staining results of the pig heart, liver, spleen, and lungs using the biological patch obtained in Example 1. As shown in Figures 2A-2B, a small number of cardiomyocytes showed hydropic degeneration (blue arrows) in the heart tissue, with swollen cell bodies and loose, lightly stained cytoplasm. No obvious interstitial proliferation, necrosis, or inflammatory cell infiltration was observed. As shown in Figures 2C-2D, the liver lobules were clearly demarcated and regularly arranged. The central vein was located in the center of the liver lobules, surrounded by hepatocytes and sinusoids arranged in a roughly radial pattern. A small number of hepatocytes showed mild fatty degeneration (yellow arrows), and round microvesicles were visible in the cytoplasm. A small number of hepatocytes were edematous (blue arrows), with swollen cells and loose, lightly stained cytoplasm. A small number of lymphocytes infiltrated around the portal areas (red arrows). As shown in Figures 2E-2F, the spleen tissue contains abundant white pulp of varying sizes and irregular shapes; the red pulp is distributed in a large area under the capsule, around the trabeculae, and lateral to the white pulp margin, consisting of splenic cords and splenic sinuses, with a small number of granulocytes visible in the marginal area and within the red pulp (red arrows). As shown in Figures 2G-2H, a small number of epithelial cells with pyknosis (black arrows) are visible within a few bronchioles of the lung tissue, and the epithelial cells are arranged irregularly; a small number of granulocytes infiltrate the alveolar walls (red arrows), and many alveoli exhibit compensatory dilation.

[0091] Figure 3 shows the HE staining results of the left and right kidneys and brain of white pigs using the biological patch obtained in Example 1. As shown in Figures 3A-3B, the glomeruli in the kidney cortex are evenly distributed, with uniform cell number and matrix. Eosinophilic material is rarely seen in Bowman's capsule (black arrows). A small number of tubular epithelial cells show hydropic degeneration (blue arrows), with cell swelling and loose, pale cytoplasm. A small number of tubular epithelial cells show vacuolar degeneration (yellow arrows), with small round vacuoles in the cytoplasm. There is no obvious proliferation in the interstitium, and no obvious necrosis or inflammatory cell infiltration. As shown in Figures 3C and 3D, the glomeruli in the kidney cortex are evenly distributed, with uniform cell number and matrix. Eosinophilic material is rarely seen in Bowman's capsule (black arrows). A large number of tubular epithelial cells show hydropic degeneration (blue arrows), with cell swelling and loose, pale cytoplasm. Lymphocyte infiltration is occasionally seen in the interstitium (red arrows). There is no obvious proliferation in the interstitium. As shown in Figures 3E and 3F, the brain tissue is rich in neurons, with many neuronal nuclei showing shrunken and deeply stained (black arrows), cell bodies shrinking and deformed, irregular in shape, and unclear boundaries between nucleus and cytoplasm. No obvious necrosis or inflammatory cell infiltration was observed.

[0092] Figure 4 shows the HE staining results of the stomach, perigastric tissue, and intestine of white pigs using the biological patch obtained in Example 1. As shown in Figures 4A-4B, the stomach tissue structure is disordered, with large areas of patch visible (black arrows). Extensive connective tissue proliferation surrounds the patch (brown arrows), with a small number of neovascularizations (green arrows) and abundant lymphocyte infiltration (red arrows); occasional endothelial cell proliferation is also observed (orange arrows). As shown in Figures 4C-4D, no obvious mucosal layer is observed in the stomach tissue; the muscular layer is well-developed, with numerous muscle cells showing hydropic degeneration (blue arrows), and the cytoplasm is loose and lightly stained, without obvious inflammatory cell infiltration. As shown in Figures 4E-4F, the intestinal tissue surface is covered with intestinal villi, and a large amount of intestinal villi epithelium is missing (brown arrows), exposing the lamina propria. In the lamina propria, the intestinal glands are loosely and irregularly arranged, with goblet cells scattered throughout. In the stroma, a large number of lymphocytes are scattered (red arrows), and a large amount of vascular congestion is visible (green arrows). Around the muscle layer, there is a large amount of connective tissue hyperplasia (orange arrows), with fibroblasts, fibroblasts, and collagen fibers loosely and irregularly arranged, a small number of new blood vessels and vascular congestion visible, accompanied by a small number of scattered lymphocyte infiltrations (yellow arrows).

[0093] Figure 5 shows the HE staining results of the white pig intestinal peritoneum tissue obtained using the biological patch obtained in Example 1. As shown in Figures 5A-5B, the intestinal tissue surface is mainly composed of columnar epithelium and goblet cells, with goblet cells scattered throughout; many mucosal epithelial cells have sloughed off (black arrows), exposing the lamina propria; the intestinal glands are loosely and irregularly arranged; and many lymphocytes are scattered throughout the stroma (red arrows).

[0094] (2) No obvious tearing was found at the nail holes and sutures of the biological patches obtained in Examples 1-16. Therefore, the biological patches with a single-line suture traction force range of 15.6-54.1N can initially meet the requirements for use in digestive surgery.

[0095] (3) Hemorrhage and effusion occurred at the anastomosis sites of the biological patches obtained in Examples 2-4, 6, and 10. Some experimental groups even showed degeneration, hyperplasia, and very severe tissue necrosis. Specifically, the biological patch obtained in Example 3 showed anastomotic hemorrhage and effusion post-surgery. One month after surgery, the hearts of two pigs showed degeneration, hyperplasia, and very severe tissue necrosis; the spleen showed relatively severe tissue necrosis; and the gastric and intestinal patches showed severe connective tissue hyperplasia. The specific pathological scoring results are as follows:

[0096] Table 5: Pathological results of Example 3 after 1 month

[0097] (4) Theoretically, the biological patch pre-placed in the anastomosis device needs to have a certain tensile strength to help ensure the compliance of the biological patch and prevent anastomotic bleeding and exudation. However, animal experiments have shown that:

[0098] Specifically, among the 10 biological patches obtained in Example 10 (tensile strength 20.7 ± 3.3 MPa), one biological patch in the experimental group showed anastomotic bleeding and exudation. However, examples with similar tensile strength to this example did not show anastomotic bleeding or exudation, such as Example 8 (tensile strength 21.1 ± 2.8 MPa) and Example 13 (tensile strength 22.9 ± 0.4 MPa).

[0099] Of the 10 biological patches obtained in Example 6 (tensile strength 29.6 ± 1.3 MPa), 4 biological patches in the experimental groups showed anastomotic bleeding and exudation. However, examples with similar tensile strength to this example did not show anastomotic bleeding or exudation, such as Example 9 (tensile strength 29.3 ± 1.1 MPa) and Example 11 (tensile strength 31.1 ± 1.7 MPa).

[0100] Of the 10 biological patches obtained in Examples 2 (tensile strength 27.4±2.1MPa), 3 (tensile strength 31.8±2.5MPa), and 4 (tensile strength 30.7±4.4MPa), 7 of the corresponding experimental groups of biological patches showed anastomotic bleeding and exudation. However, examples with similar tensile strength to several examples did not show anastomotic bleeding or exudation, such as Examples 12 (tensile strength 28.2±1.8MPa) and 15 (tensile strength 26.1±3.2MPa), as well as Examples 1 (tensile strength 32.3±1.8MPa), 7 (tensile strength 33.5±0.9MPa), and 16 (tensile strength 37.5±1.8MPa).

[0101] The above experiments show that a maximum tensile elongation range of 14.8-44.6% can meet the requirements for installation on a stapler.

[0102] Because the tensile strength of biological patches fluctuates greatly, and animal experiments have shown that the correlation between the tensile strength of biological patches and anastomotic bleeding and exudation is unstable, the inventors speculate that the tensile strength of biological patches cannot be used as a parameter for screening biological patches, and that mechanical parameters that can indicate anastomotic bleeding and exudation need to be reconsidered.

[0103] Based on years of research on the application of animal-derived biomaterials in digestive surgical implantation, the inventors discovered that anastomotic bleeding and effusion can occur due to a mismatch between the stapling height and tissue thickness. While the stapling height is fixed, tissue thickness varies among patients and at different sites. When the tissue is too thick or too thin relative to the stapling height, anastomotic bleeding and effusion may occur. Therefore, bio-membranes need to have excellent resilience. The inventors aim to introduce "elasticity" into bio-derived bio-membranes and replace "tensile strength" with "elastic deformation rate." They will continue to explore digestive surgical bio-membranes that prevent anastomotic bleeding and effusion by combining three mechanical parameters: elastic deformation rate, maximum tensile elongation, and single-suture traction force.

[0104] IV. Determination of elastic deformation rate

[0105] 1. Measurement Method

[0106] A 4cm long and 1cm wide biological patch was clamped along its length onto a tensile testing machine. A tensile load was applied at a speed of 100mm / min to stretch the biological patch until it broke. A tensile curve was plotted, and the elastic deformation rate of the biological patch was calculated based on the elastic deformation segment of the tensile curve during the test.

[0107] 2. Measurement Results

[0108] Table 3: Elastic deformation rate of Examples 1-17

[0109] Table 3 shows that the elastic deformation rate of the biological patches obtained in Examples 1-17 is relatively stable, and the range of elastic deformation rate is 4.4-39.1%.

[0110] Based on the results of animal experiments, the inventors unexpectedly discovered that in all cases, 7 pigs experienced bleeding and oozing with the biological patches obtained in Examples 3 (elastic deformation rate 4.4±0.7%), 4 (elastic deformation rate 5.2±0.1%), and 2 (elastic deformation rate 6.5±0.1%); 4 pigs experienced bleeding and oozing with the biological patch obtained in Example 6 (elastic deformation rate 7.6±0.2%); and only 1 pig experienced bleeding and oozing with the biological patch obtained in Example 10 (elastic deformation rate 10.2±1.3%). That is, as the elastic deformation rate increased, the number of pigs experiencing anastomotic bleeding and oozing decreased continuously, and the elastic deformation rate of the biological patches obtained in these examples was lower than that of the examples in which no anastomotic bleeding and oozing occurred.

[0111] Therefore, the inventors hypothesized that a higher elastic deformation rate reduces the likelihood of anastomotic bleeding and effusion. Based on animal experiments, the results preliminarily confirm the accuracy of the inventors' introduction of the "elastic deformation rate." The hypothesized cause of anastomotic bleeding and effusion is due to the poor resilience of the biological patch, its slightly poor adhesion to the pig's tissue, and insufficient contractile elasticity at the pin holes and sutures. Furthermore, based on animal experiments using the biological patches obtained in Examples 1, 5, 7-9, and 11-16, the elastic deformation rate should be controlled within the range of 13.7-39.1%.

[0112] V. Clinical Trial 1

[0113] 1. Inclusion criteria, exclusion criteria, and total number of enrolled cases

[0114] (1) Inclusion criteria

[0115] ① Age: 18-75 years old, gender not limited; ② Meets the clinical surgical indications, and requires surgical resection, closure, and anastomosis of the esophagus, stomach, and intestine for various digestive tract diseases (surgical approach is not required, traditional open, laparoscopic, and robotic approaches are all acceptable); ③ Can understand the purpose of the trial, is willing to participate and sign an informed consent form, and is willing to accept relevant examinations and clinical follow-ups.

[0116] (2) Exclusion criteria

[0117] ① Eastern Cooperative Oncology Group (ECOG) Performance Status Score of 2 or higher. The ECOG Performance Status Score is a scoring system used to assess the daily living activities and self-care abilities of cancer patients; ② American Society of Anesthesiologists (ASA) Class III or higher (excluding Class III); ③ Presence of autoimmune disease or hematologic disorders; ④ Diagnosis of a confirmed intra-abdominal infection; ⑤ ALT or AST / AST ratio greater than 2.5 times the upper limit of normal, or total bilirubin greater than 1.5 times the upper limit of normal, or serum creatinine less than 1.5 times the upper limit of normal; ⑥ Hemoglobin level < 60 g / L or platelet level < 100 × 10⁻⁶. 9 / L or serum albumin less than 30g / L; ⑦ Any coagulation function indicator exceeding the normal reference range by ±10%, including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), and international normalized ratio (INR); ⑧ Presence of severe liver disease, severe kidney disease, severe respiratory disease, or uncontrolled diabetes, hypertension, arrhythmia, or other chronic systemic diseases; ⑨ Myocardial infarction within the past 6 months; ⑩ Receiving preoperative chemotherapy or radiotherapy within the past 4 weeks; Pregnant women, breastfeeding women, or those planning to become pregnant during the trial; They are currently participating in other drug or medical device clinical trials and have not yet reached their primary study endpoint; Other circumstances deemed unsuitable for participation in this clinical trial by the researchers.

[0118] 2. Experimental Grouping

[0119] Experimental group: divided into 11 groups, each using biological patches obtained from Examples 1, 5, 7-9, and 11-16 respectively for surgery. Before surgery, the biological patches were pre-placed on the stapler.

[0120] Control group: The surgery was performed using only a stapler for closure / anastomosis.

[0121] 3. Test Procedure

[0122] (1) Sign the informed consent form; (2) Screen cases, confirm clinical inclusion and exclusion criteria, and complete baseline data collection simultaneously; (3) Determine the operation time; (4) Enroll the experimental group or control group according to the randomization; (5) Perform the operation; (6) Observe bleeding points and record them in the surgical report; (7) Assess the immediate postoperative condition of the subjects; (8) Complete the relevant examination requirements in the protocol for the subjects before discharge, 1 month after surgery, and 3 months after surgery. See the table below for the specific procedures.

[0123] Table 6: Main Test Procedures

[0124] 4. Therapeutic Indicators

[0125] (1) Within 10 minutes of completing the cutting, closing, and anastomosis by firing the anastomosis device (after completing the cutting, closing, and anastomosis, the researcher observes until no more bleeding points are added to the anastomosis as defined in the protocol), the number of bleeding points per unit length of anastomosis / closure requiring clinical hemostasis and suturing reinforcement (observation sites: gastric resection end, duodenal closure end, intestinal closure end, gastrointestinal anastomosis, esophageal anastomosis, esophagogastric anastomosis, esophagojejunal anastomosis, intestinal anastomosis, etc.).

[0126] Number of bleeding points per unit length of anastomosis / closure = Total number of bleeding points / Cutting edge length (cm).

[0127] Judgment criteria: ① Visit time: Visit 1 (on the day of surgery); ② Bleeding points requiring clinical treatment: within 10 minutes of completing the cutting, closing, and anastomosis (after the researcher observes until no new bleeding points as defined in the protocol are added to the anastomosis), the site where additional procedures (such as manual pressure ligation, hemostatic clips, or electrocoagulation) are required at the cut edge of the suture tissue to achieve clinical hemostasis and suture reinforcement.

[0128] (2) Within 10 minutes of completing the cutting, closing, and anastomosis (after the researchers observe until no more pulsating bleeding points are added to the anastomosis as defined in the protocol), the number of pulsating bleeding points per unit length of the anastomosis / closure requiring clinical hemostasis (observation sites: gastric resection end, duodenal closure end, intestinal closure end, gastrointestinal anastomosis, esophageal anastomosis, esophagogastric anastomosis, esophagojejunal anastomosis, intestinal anastomosis, etc.); time for anastomotic / suture bleeding point treatment (s); total surgical time (min) (from the start of the surgery to the completion of abdominal closure).

[0129] Judgment criteria: Visit time: Visit 1 (on the day of surgery); Pulsating bleeding point: bleeding from a small artery, record the bleeding point (take a photo). Bleeding point treatment time (s): the time recorded from the start of the intervention to the completion of the hemostasis operation. If multiple hemostasis treatments are performed on the same bleeding point, the bleeding point treatment time is the sum of the times of the multiple hemostasis treatments.

[0130] (3) Safety evaluation indicators

[0131] ① The occurrence of anastomotic-related postoperative complications (anastomotic bleeding, anastomotic leakage, anastomotic stenosis) within 90 days postoperatively. Specifically, these include the following complications:

[0132] A. Anastomotic bleeding: refers to persistent or intermittent bloody stools in patients after digestive tract reconstruction. When massive bleeding causes hemodynamic disturbances, symptoms such as tachycardia, hypotension, decreased hemoglobin levels, and even decreased urine output may occur. If there is massive bleeding in the abdominal cavity, it may also cause abdominal distension.

[0133] B. Anastomotic leakage: refers to the leakage of food residue or digestive juices into the abdominal cavity due to poor healing or incomplete anastomosis at reconstructed anastomoses such as esophageal-gastric, esophageal-jejunal, gastric-duodenal, gastric-jejunal, or jejunal-jejunal anastomoses during digestive tract reconstruction.

[0134] C. Anastomotic stricture: Anastomotic stricture in the upper digestive tract means that the anastomosis cannot be passed through a narrow endoscope with a diameter of 7.9 mm, and is accompanied by difficulty swallowing; in the lower digestive tract, it means that the anastomosis cannot be passed through a fiberoptic colonoscope with a diameter of 13 mm, and is accompanied by difficulty defecating.

[0135] ② Measurement method: The occurrence of the above complications shall be judged and recorded according to the routine clinical methods.

[0136] ③ Visit time points: Visit 1 (on the day of surgery), Visit 2 (before discharge), Visit 3 (30 days ± 10 days after surgery), Visit 4 (3 months ± 14 days after surgery).

[0137] 6. Test Methods

[0138] Prospective, multicenter, randomized controlled, open-label, and superior.

[0139] 7. Test Results

[0140] (1) Security

[0141] No complications such as anastomotic bleeding, anastomotic leakage, or anastomotic stenosis occurred in any of the patients within 90 days postoperatively.

[0142] (2) Record of surgical bleeding points

[0143] Table 7: Record of bleeding points during colon surgery

[0144] Note: The biological patches obtained in each example are numbered 1-10 respectively; "Experimental Group 1 (Example 1-1)" means that Experimental Group 1 uses patch No. 1 obtained in Example 1; "Experimental Group 2 (Example 1-2)" means that Experimental Group 2 uses patch No. 2 obtained in Example 1.

[0145] The experimental results in Table 7 show that, compared with experimental groups 9 (Example 9-1), 10 (Example 9-2), 3 (Example 5-1), and 4 (Example 5-2), the biological patch obtained in Example 5 (elastic deformation rate 13.7±0.3%) had a similar elastic deformation rate to that obtained in Example 9 (elastic deformation rate 13.9±1.1%). However, experimental groups 9 (Example 9-1) and 10 (Example 9-2) showed a greater number of bleeding points and / or pulsatile bleeding points requiring clinical hemostasis. Therefore, the inventors speculate that the occurrence of bleeding points is not solely due to the small elastic deformation rate.

[0146] Further comparison revealed that the elastic deformation rate as a percentage of maximum tensile elongation of the biological patch obtained in Example 5 was greater than that of the biological patch obtained in Example 9. The inventors hypothesized a correlation between the elastic deformation rate as a percentage of maximum tensile elongation and clinical outcomes, which was further verified in clinical trials. Based on Example 13 (elastic deformation rate as a percentage of maximum tensile elongation of 39%), they boldly set the initial elastic deformation rate as a percentage of maximum tensile elongation for colon surgery to be no less than 39%.

[0147] Table 8: Values ​​of elastic deformation rate as a percentage of maximum tensile elongation of biological patches obtained in Examples 1-17

[0148] The range of elastic deformation rate as a percentage of maximum tensile elongation obtained from Examples 1-17 is 20-89%.

[0149] Table 9: Record of bleeding points during rectal surgery

[0150] The experimental results in Table 9 show that experimental groups 3 (Examples 5-3), 4 (Examples 5-4), 9 (Examples 9-3), 10 (Examples 9-4), 15 (Examples 13-3), and 16 (Examples 13-4) had a relatively large number of bleeding points and / or pulsatile bleeding points requiring clinical hemostasis.

[0151] Based on the conclusions of the colon surgery, the inventors speculate that the reason why there were more bleeding points and / or pulsatile bleeding points requiring clinical hemostasis in experimental group 3 (Example 5-3) and experimental group 4 (Example 5-4) is because the elastic deformation rate of the obtained biological patch was low. The reason why there were more bleeding points and / or pulsatile bleeding points requiring clinical hemostasis in experimental group 15 (Example 13-3) and experimental group 16 (Example 13-4) is because the elastic deformation rate of the obtained biological patch was smaller as a percentage of the maximum tensile elongation.

[0152] The reason why there were more bleeding points and / or pulsatile bleeding points requiring clinical hemostasis in experimental group 9 (Example 9-3) and experimental group 10 (Example 9-4) may be due to the low elastic deformation rate of the obtained biological patch, or it may be due to the small value of the elastic deformation rate of the obtained biological patch relative to the maximum tensile elongation.

[0153] Clinical trials of rectal surgery have further verified the correlation between the elastic deformation rate as a percentage of the maximum tensile elongation and bleeding and exudation from biological patches.

[0154] Since the elastic deformation rate of the biological patch obtained in Example 14 accounts for 50% of the maximum tensile elongation, the elastic deformation rate of the biological patch should be controlled within the range of 14.6-39.1% during rectal surgery, and the value of the elastic deformation rate accounting for the maximum tensile elongation should not be less than 50%.

[0155] Table 10: Record of bleeding points during ileal surgery

[0156] As shown in Table 10, during ileal surgery, experimental groups 9 (Examples 9-5) and 10 (Examples 9-6) experienced a relatively large number of bleeding points requiring clinical hemostasis. The presumed reason is that the elastic deformation rate of the biological patch obtained in Example 9 was relatively low compared to its maximum tensile elongation. Therefore, during ileal surgery, the elastic deformation rate of the biological patch should be controlled within the range of 13.7-39.1%, and the elastic deformation rate should be no less than 39% of the maximum tensile elongation.

[0157] Table 11: Record of bleeding points during duodenal surgery

[0158] Table 11 shows that experimental groups 9 (Examples 9-5), 10 (Examples 9-6), 15 (Examples 13-7), and 16 (Examples 13-8) had a higher number of bleeding points requiring clinical hemostasis and / or pulsatile bleeding points. Therefore, the preliminary conclusion is that during duodenal surgery, the elastic deformation rate of the biological patch should be controlled within the range of 13.7-39.1%, and the elastic deformation rate should account for no less than 50% of the maximum tensile elongation.

[0159] Table 12: Record of bleeding points during gastric surgery

[0160] In experimental groups 1 (Examples 1-9), 2 (Examples 1-10), 9 (Examples 9-9), and 10 (Examples 9-10), the bio-membranes showed tearing at the nail holes and sutures, with bleeding and exudation at the anastomosis, and the tearing worsened over time. However, the bio-membranes in experimental groups 3 (Examples 5-9) and 4 (Examples 5-10) did not show significant tearing. Therefore, the inventors speculate that during gastric surgery, the single-line suture traction force of the bio-membranes should be controlled to be no less than 19.7 N.

[0161] Table 12 shows that experimental groups 3 (Examples 5-9), 4 (Examples 5-10), 9 (Examples 9-9), 10 (Examples 9-10), 15 (Examples 13-9), 16 (Examples 13-10), 17 (Examples 14-9), and 18 (Examples 14-10) had a relatively high number of bleeding points and / or pulsatile bleeding points requiring clinical hemostasis. This is presumably because the biological patch obtained in Example 5 had a relatively low elastic deformation rate. The biological patches obtained in Examples 13 and 14 had relatively low elastic deformation rates relative to their maximum tensile elongation. The biological patch obtained in Example 9 also had a relatively low elastic deformation rate or a relatively low elastic deformation rate relative to its maximum tensile elongation.

[0162] Preliminary conclusions can be drawn from this: during gastric surgery, the single-line suture traction force of the biological patch should be controlled to be no less than 19.7 N, the elastic deformation rate should be in the range of 14.6-39.1%, and the value of the elastic deformation rate as a percentage of the maximum tensile elongation should be no less than 56%.

[0163] (3) Mechanical parameters of biological patches required for different digestive surgical sites

[0164] Table 13: Mechanical parameters of biological patches used in surgeries at different sites

[0165] Based on the results of the above clinical trials, biological patches with a maximum tensile elongation range of 14.8-44.6%, an elastic deformation rate range of 14.6-39.1%, an elastic deformation rate accounting for 56-89% of the maximum tensile elongation, and a single-line suture traction force of 19.7-54.1N will be suitable for digestive surgery in areas including the colon, rectum, ileum, duodenum, and stomach.

[0166] VI. Clinical Trial II

[0167] (1) A biological patch with the following parameters was obtained by adjusting the preparation method:

[0168] Table 14: Biomechanical parameters of Examples 18-20

[0169] Table 15: Main differences in the preparation methods of Examples 18-20

[0170] Based on the first clinical trial, 88 more patients were enrolled to further verify the impact of the elastic deformation rate as a percentage of the maximum tensile elongation on the clinical application effect.

[0171] Table 16: Results of Clinical Trial 2

[0172] Note: The number before " / " is the number of cases requiring clinical hemostasis treatment for more than 5 bleeding points or pulsatile bleeding points. If the same patient requires clinical hemostasis treatment for more than 5 bleeding points and pulsatile bleeding points, it is counted as 1 case. The number after " / " is the total number of patients.

[0173] The elastic deformation rate as a percentage of maximum tensile elongation of the biological patches obtained in Examples 18 and 19 is less than the requirement derived from Clinical Trial 1. This indicates that a relatively large number of patients undergoing digestive surgery at different sites required clinical hemostasis for bleeding points or pulsating bleeding points greater than 5. The elastic deformation rate as a percentage of maximum tensile elongation of the biological patch obtained in Example 20 only meets the requirements for colonic and ileal surgery. This shows that the number of patients undergoing colonic and ileal surgery requiring clinical hemostasis for bleeding points or pulsating bleeding points greater than 5 is significantly reduced, while the number of patients undergoing rectal, duodenal, and gastric surgery requiring clinical hemostasis for bleeding points or pulsating bleeding points greater than 5 is relatively high.

[0174] Table 16 further demonstrates that the ratio of elastic deformation rate to maximum tensile elongation is indeed related to bleeding or exudation of biological patches. If the elastic deformation rate and maximum tensile elongation are too small, the incidence of complications such as anastomotic bleeding and exudation will increase.

[0175] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A digestive surgery biologic patch, characterized in that, The maximum tensile elongation of the biological patch is not less than 14.8%, the elastic deformation range is not less than 13.7%, and the single-thread suture tension is greater than 15.6N.

2. The digestive surgery biosurgical patch according to claim 1, wherein, The maximum tensile elongation of the biological patch is 14.8-44.6%, the elastic deformation range is 13.7-39.1%, the single-thread suture tension is 15.6-54.1N, and the elastic deformation accounts for 39-89% of the maximum tensile elongation.

3. The surgical mesh of claim 1, wherein the bioabsorbable polymer is a copolymer of glycolide and lactide. The maximum tensile elongation of the biological patch is 14.8-44.6%, the elastic deformation range is 14.6-39.1%, the single-thread suture tension is 15.6-54.1N, and the elastic deformation accounts for 50-89% of the maximum tensile elongation.

4. The digestive surgery biosurgical patch according to claim 1, wherein, The maximum tensile elongation of the biological patch is 14.8-44.6%, the elastic deformation range is 13.7-39.1%, the single-thread suture tension is 15.6-54.1N, and the elastic deformation accounts for 50-89% of the maximum tensile elongation.

5. The digestive surgery biosurgical patch according to claim 1, wherein, The maximum tensile elongation of the biological patch is 14.8-44.6%, the elastic deformation range is 14.6-39.1%, the single-thread suture tension is 19.7-54.1N, and the elastic deformation accounts for 56-89% of the maximum tensile elongation.

6. The digestive surgery biosynthetic patch of claim 2, wherein, The digestive surgery biological patch is a colon or ileum surgery biological patch.

7. The surgical mesh of claim 3, wherein the bioabsorbable polymer is a copolymer of glycolide and lactide. The digestive surgery biological patch is a rectum surgery biological patch.

8. The digestive surgery biosurgical patch according to claim 4, wherein, The digestive surgery biological patch is a duodenum surgery biological patch.

9. The digestive surgery biosurgical patch according to claim 5, wherein, The digestive surgery biological patch is a stomach surgery biological patch.

10. The digestive surgery biopatch according to any one of claims 1 to 9, characterized in that, The digestive surgery biological patch is a bovine pericardium-derived biological patch.

11. The digestive surgery biopatch according to any one of claims 1 to 9, characterized in that, The digestive surgery biological patch is provided with two perforations located at opposite ends of the biological patch.

12. An anastomat kit comprising the digestive surgery biological patch of any one of claims 1-9.

13. A method of making a digestive surgery bioprosthetic patch according to any one of claims 1-9, characterized in that, The steps include: (1) soaking healthy bovine pericardium sheet tissues in low-osmotic Hank's solution, repeatedly replacing the low-osmotic Hank's solution through multiple rinsing to sufficiently swell and break various cells present in the tissues; (2) repeatedly rinsing the tissues treated in the above step in physiological saline for 60-120 min each time, replacing the physiological saline each time, and performing total rinsing until no visible cells or cell components and cell debris are observed under a microscope and no soluble proteins and nucleic acids are detected through protein and nucleic acid quantitative determination; (3) removing phospholipids and non-structural proteins and part of tissue matrix such as hyaluronic acid, various chondroitin sulfates, and mucopolysaccharides, etc. immunogenic molecules in the tissues using a surfactant solution of Tween 80; (4) soaking in a glutaraldehyde solution with a concentration of 0.5-1.5% for 3-3.5 h; (5) The pretreated tissue material is placed in a Cr 3+ The ion concentration is 0.0625 mol / dm 3 In a hydroxyl chromium solution with OH / Cr of 0.5, the material is oscillated in a water bath at 35-42°C for 3.5-5h; the pH of the material treatment solution is detected and increased by 0.3-0.5 pH units using 10% NaHCO3, and then oscillated in a water bath at 40-46°C for 60 min.

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