Overview of SuturingA suture is the stitch or stitches used two unite to areas of tissue. Sutures are commonly used to close a wound or a surgical incision and promote healing. Several different suturing methods can be used, depending on the nature and shape of the incision or wound. Some sutures are absorbable, meaning the stitches are absorbed over time as the wound heals by the healthy surrounding tissue. Catgut, which is obtained from sheep intestine, is a popular absorbable material. Non-absorbable sutures must be removed after the wound heals. These generally are made from strands of silk, cotton or linen, plastic, and alloy steel wire. These materials vary considerably in length of time they retain their strength, the reaction they provoke in the tissues, and their likelihood of allowing infection to occur.Absorbable sutures are made from sterile strands of tissue obtained from healthy animals or from synthetic means. These strands are absorbed over time by the living tissue surrounding them and therefore are not permanent. These strands are available in various diameters and tensile strengths and they may be treated with coloring material so that they are less visible and they can be treated to control the rate of absorption. A catgut or Vicril suture is one of the most common types of absorbable suture.Styles of Suture Needles:Knots:1. first tie of half-hitch2. square knot3. surgeons knot4. triple, or reinforced surgeons double slip5. granny knot avoid this!6. half-hitch knotCommon styles:1. A simple interrupted suture is a series of single stitches inverted and tied separately along the length of the suture. The needle is inserted into one skin edge, through the entire depth of the wound, and out the other skin edge. Each stitch is then tied at the side using a square knot. 2. The simple interrupted mattress or Halstead suture is an interrupted inverting stitch that is placed through the subcutaneous fascia and runs parallel to the wound. The suture is tied on one side. An interrupted suture is a single stitch inverted and the ends are tied together.3. A simple continuous suture is a spiral suture that runs the entire length of the wound with only two anchoring knots, at the beginning and at the end.4. A continuous mattress or Cushing suture is an inverting suture predominantly used in abdominal surgery. The suture is a running horizontal suture, which utilizes a double stitch that forms a loop about the tissue on both sides of the wound. The suture is passed through the seromuscular layers (thin muscular layers) of the gastrointestinal tract.5. A blanket suture is a continuous self-locking stitch, very similar to the blanket stitch used in embroidery. It is also referred to as the lock-stitch suture because a continuous lock-stitch is used to close the skin of a wound.6. A purse-string suture is a surgical suture passed as a running stitch (continuous and inverted) in and out along the edge of a circular wound, similar to that of a purse-string, hence the name. When the ends come together, in a circular formation, they are drawn tight and the wound is closed tight like a purse. This suture method is used to close the end of an appendiceal stump or to close a hernia.Other Styles:1. The Lambert suture generally is used in abdominal surgery. It is an inverting suture, that can be either continuous or interrupted, used to join two segments of an intestine without entering the lumen (the inner channel through which stomach contents flow).1. The button suture is a method in which the ends of the strands are placed through the eyes of a small knob or disc, called a button, and then tied. The buttons prevent the ends from being pulled through the tissue by the tension of the suture and cutting the flesh.3. A cobbler suture is a doubly-armed suture made with a needle at each end of the strand. The method of stitching is the same as that used by cobblers making shoes, hence the name cobbler suture.4. Connell's suture is a variation of the continuous suture. A continuous suture is one in which intermittent knots are not tied. Only the knot at the beginning and end of the suture length binds the suture. The Connell method also inverts the opposing edges. The Connell's suture is most often used for inverting the gastric or intestinal walls in performing anastomosis (i.e. a connection between two or more blood vessels).5. Retention sutures, also called stay sutures, are very large sutures (stitches) used in addition to smaller skin sutures. They attach underlying tissues of fat and muscle as well as skin and are used to support incisions in obese individuals or when healing may be prolonged. The sutures are frequently left in place fourteen to twenty-one days. To prevent these large sutures from irritating the incision, rubber tubing may be placed over them or a roll of gauze under them extending down the incision line.