外科缝线基础知识（Basics of surgical sutures）Surgical sutures are necessary materials for surgeons, and download this knowledge from other websites in the hope that they will be useful to youIdeal stitching materials shall meet the following conditions:1. versatility, which can be applied to any surgical procedure (of course, taking into account the differences in stitch type and tensile strength);2. sterility;3., no electrolysis, no capillary action, no allergy and no carcinogenicity;4. if stainless steel suture, must have no magnetism;5. easy to operate;6., the tissue reaction is slight, is not conducive to bacterial growth;7. do not loosen the knot, the suture itself does not wear or split;8. does not shrink within the tissue;9. suture after the arrival of, can be absorbed, and only minor reactions.However, because of this ideal versatility, sutures do not currently exist, so surgeons must choose sutures that are as close as possible to the ideal and have the following characteristics:1., tensile strength uniform, in order to use the finer type of suture;The diameter of the 2. sutures is uniform and constant;3. sterility;4. strong flexibility, easy to operate, safe ligation;5. does not contain irritating substances or impurities to facilitate tissue compatibility;6. suture results can be trusted.Model and tensile strengthThe model indicates the diameter of the stitching material. Surgical practice is generally accepted that the finest type of suture that allows tissue to fit safely should be selected to minimize the suture induced trauma. The number of stitches is indicated by numbers: "No. 0" or more. The larger the number, the thicker the seam, such as "No. 3 is thicker than 1"; from "0", "0", the smaller the diameter, the lower the tensile strength.The tensile strength of a suture is what it can withstand beforebreaking (expressed in pounds). The tensile strength of the tissue is a prerequisite for the surgeon to select the type of suture and the tensile strength. The surgeon should also understand, thread strength decreasing and the relationship between the tensile strength increasing wound resistance between the implant materials and whether caused by foreign body reaction affect the healing process of the organization. It is generally accepted that the tensile strength of the suture does not exceed the tensile strength of the tissue, but at least it should be stronger than the normal tissue.Single fiber and multi fiber sutureThe single fiber suture is made of a single fiber, which is less resistant to passing through the tissue and prevents bacteria from sticking. Because of these characteristics, it is especially suitable for vascular surgery. Single fiber sutures are easy to tie. But in operation and ligation must be careful, because folding or curling may cause suture gap or weak point, so that fracture.Absorbable and non absorbable suturesAbsorbable sutures are prepared from the collagen or synthetic multimeric system of healthy mammals. Natural absorbable suture is through the human digestive enzymes to degrade fiber suture. The synthetic absorbable suture is first through hydrolysis, decomposition of the water gradually penetrated into the suture fiber caused by the polymer chain; and natural absorbable suture than synthetic absorbable sutures can be hydrolyzed after implantation only caused mild tissuereaction.In the first phase of suture absorption, tensile strength showed a linear and gradual decrease, which occurred within a few weeks after surgery. The second stage often overlaps with the first stage, and eventually the suture disappears.An absorbable suture that is free of enzyme digestion and hydrolysis. Its scope of application is as follows:The skin should be removed after the wound is healed;The suture in the body, leaving the length inside the tissue;Suitable for allergic, scar, or organized hypertrophy of absorbable sutures;A temporary device used to secure a defibrillator, pacemaker, or drug release device.Introduction of various suture materialsNatural absorbable sutureSurgery can be divided into: catgut catgut and chromic catgut in general. Both are processed from highly purified collagen. Surgical catgut absorption rate depends on the type of line, organizational type and condition as well as the patient's general condition. Can be used for surgical catgut suture wound infection, but the absorption rate.General surgical catgut fast absorption. Postoperative tensile strength was maintained for only 7-10 days and was completely absorbed within 70 days. The chromate solution catgut called chrome catgut, digestive enzymes function against the body, the absorption time is extended to more than 90 days.Synthetic absorbable sewing moneyBecause the natural gut has strong antigenicity, tissue reaction and the disadvantage of receiving rate are people, is committed to the development of synthetic absorbable sutures. The latter has a wide range of applications, ranging from thoracic and abdominal wound sutures to ophthalmic surgery.Coated Vicryl (Polyglactin 910) suture: it has the advantage of:1. smooth through tissue;2. knot smooth, accurate positioning;3. reduce the tendency to clamp tissue;4. can be used to stitch infected wounds.The coating is PLLA and ethylene to lipid (Polyglactin 370) copolymer mixture made with calcium stearate. The coating has remarkable absorbability, adhesion and lubricity without stripping.The tensile strength of the coated Vicryl suture remained about65% at fourteenth days after the suture. Twenty-first days after suture, 6 a 0 or more coarse type suture tensile strength of about 7 and retained 40%, a 0 or more thin line retained only about 30%. Within 40 days, the stitches were hardly absorbed, and were absorbed in 56 and 70 days. The absorption of the paint is also very rapid, and it is estimated to be between 56 and 70 days.Polydioxanone (PDS II) suture: this single fiber suture represents significant progress in suture materials. It is soft, flexible and single fiber structure characteristics in one, good absorption properties, can maintain the tensile strength of the wound more than 6 weeks (two times for other synthetic absorbable sutures), mild tissue reaction and low affinity to bacteria. The utility model is suitable for suture of a plurality of soft tissues, and can be used for cardiovascular, obstetrical, ophthalmology, plastic surgery, digestive tract and colon operation in children.Similar to other synthetic absorbable sutures, PDS II loops are absorbed in vivo by hydrolysis. After the suture, the tensile strength of the fourteenth Tianbao was about 70%, 50% on the 28 day and 42 on the 25% day. The suture was hardly absorbed within 90 days after operation and was completely absorbed after 6 monthsMonocryI (PoIiglecaprone 25) suture: this kind of single fiber suture is flexible, easy to operate, easy to knot, no chemical action in the tissue, and can be absorbed as scheduled. Surgeons commonly use tissue suture requiring higher tensile strength within two weeks after surgery, which is suitable forsubcutaneous suture, soft tissue alignment and ligation besides nerves, blood vessels, ophthalmology and microsurgery. The original strength of 50%~60% could be retained at seventh days, decreased to 20%~30% at fourteenth days, and disappeared at twenty-first days. 91 and 119 days are completely absorbed.Absorbable sutureThe USP divides non absorbable surgical sutures into the following categories:Class I: twisted or woven or single fiber yarn or synthetic fiber;Class II: cotton or linen fibers, coated with natural or synthetic fibers, used to thicken seams without increasing strength;Class III: a single strand or multiple strands of metal wire.Surgical threadBecause of the excellent operability of the surgical thread, it has become a standard for surgeons to evaluate the performance of new synthetic materials. The natural single fiber silk can be made into silk thread by two kinds of twisting, twisting or knitting processes, among which the knitting type surgical thread has the best operation performance.Alloy sutureStainless steel suture: the basic characteristics include non-toxic, easy bending, slender and so on. Two kinds of suture, single fiber and twist twist, have the advantages of large tensile strength, low tissue reaction and convenient knot tying. As long as the suture is not broken, the tensile strength of the tissue is very little changed. The stainless steel suture can be used for abdominal wall, sternal suture, skin suture, tension reduction suture, and various orthopedic and Department of Neurosurgery operations.Synthetic non absorbable sutureNylon suture: a chemically synthesized polyamide polymer. Because of its better elasticity, it is especially suitable for tension reduction, suture and skin suture. In vivo, nylon sutures are hydrolyzed at a rate of 15%~20% per year. The single strand nylon thread has the tendency to restore its original linear state ("memory" characteristic), so it should be more than a few times to make sure that it is safe and reliable when compared with the woven nylon suture.ETHILON is a nylon suture with minimal tissue response, in which the very fine model (9-0,10-0) is dyed black and is often used in ophthalmology and microsurgery.NUROLON is made of nylon fiber fine knit and coated to improve its operability. The appearance, feel and operation are like silk thread, but the intensity is greater and the reaction of tissue is slight. Any tissue that can be applied to multiple strands without absorbable sutures.Polyester fiber suture: by the treated polyester fiber (poly ethylene terephthalate) multi fiber suture closely woven, a natural fiber tougher before use wet will not weaken the strength of the organization, reflect slight. Polyester fiber suture is the best material to suture artificial blood vessel.MERSILENE polyester fiber suture can be retained in the body for a long time, providing accurate and uniform tension, rarely damaged, and without the need to stimulate the removal of suture residue. After eye surgery, the MERSlLENE suture hardly causes burning pain and itching. Because of the absence of a coating, the MERSlLENE thread passes through the tissue with a higher coefficient of friction.ETHlBOND high quality polyester fiber threads are evenly coated with polybutilate. The latter is the first kind of coating specially used as a lubricant for surgical sutures. It can adhere to stitches of woven polyester fibers. This kind of coating makes knitting stitches easy to traverse,It has excellent flexibility and operability, and can be firmly ligated and fastened. The pharmacological properties of suture materials and coatings are not active, and the tissue response is slight, and the strength of the suture can be maintained for a long time in vivo. ETHIBOND quality suture is mainly used in cardiovascular surgery, such as vascular anastomosis, artificial blood vessel or valve suture, etc.. ETHIBOND high quality polyester suture can also be used with TEFLON or polyester pad. The small spacer serves as a support under the suture to prevent avulsion of the adjacent fragile tissue. Small pads are routinely used in valve surgery and are used incases of abnormal deformity, distortion, or destruction of the valve ring.Polypropylene (POLYPROPYLENE) sutures: polypropylene sutures are a solid isomer of linear hydroxy polymers. The polypropylene thread produced by the patented process increases flexibility and is easy to use. Not easily degraded or weakened by enzymes. The activity of the tissue is very weak and the tissue is mild and the tensile strength can be maintained in the body for two years. Compared with other types of single fiber suture, knot knot is more stable and firm.PROLENE polypropylene suture has been widely used in general surgery, cardiovascular surgery, plastic surgery and ophthalmology. The suture has weak biological activity and is not easy to adhere to tissues and is easy to remove. PROLENE can be used to suture pollution and wound infection, sinus formation and suture the post discharge can be reduced to the lowest level.Selection principle of sutureAmong the many choices surgeons face, the choice of sutures for different operations is also one of the key issues. Of course, the surgeon's personal preference plays a role, but the various factors affecting the healing, the characteristics of the tissue involved, and the possible postoperative complications will affect the final selection of the suture.A wide variety of suture materials may make people feel at a loss when making a choice. The following principles are usedas guidelines:1. when the wound reaches maximum strength, sutures are no longer needed. Therefore:Also must use non absorbable suture or aging long absorbable suture to suture the slow healing tissues (such as skin, fascia, tendon, etc.);Those with absorbable suture suture to heal faster tissue (such as stomach, colon, bladder, etc.).2., the organization of foreign body memory can make pollution into infection. Therefore:Those in suture wound contaminated, avoid the use of multiple fiber sutures;The use of single fiber suture or absorbable suture.3., in emphasizing the beauty of the site, should pay attention to precise and long time to organize, and avoid the use of various stimuli. Therefore:The use of the most slender, no reaction of single fiber suture material (such as nylon, polypropylene);"As far as possible at the same time suturing subcutaneous tissue;Even if circumstances permit, the application of sterile skinadhesive tape.4. in a high concentration crystalloid solution, any foreign substance may precipitate precipitation and stone formation. Therefore:Those in the urinary tract and biliary surgery, should use absorbable suture5. about the choice of stitch type:The use of sutures and natural strength to match the seam line;。
