Dr. Shoshana Weiner DNP, FNP-BC Suturing Dr. Shoshana Weiner DNP, FNP-BC

Types of Suture Material Absorbable sutures, such as polyglactin 910 (Vicryl), polyglycolic acid (Dexon), and poliglecaprone 25 (Monocryl), are used to close deep, multiple-layer lacerations. Although these sutures absorb at varying rates, they all usually absorb within four to eight weeks. Nylon, monofilament non absorbable sutures (e.g., polypropylene [Prolene] ) must eventually be removed.

Absorbable Suture Material Surgical gut also known as catgut was the first absorbable suture material available. Despite its name, catgut was never made from cat intestines. It is actually made by twisted fiber formed from the collagen of the intestines of sheep, cattle, or goats. Surgical gut is packaged in alcohol to prevent it from drying and breaking. The 3 forms available are plain, chromic, and fast-absorbing (Ethicon). Plain gut causes a marked inflammatory reaction in tissue and it can maintain its tensile strength for only 7-10 days after placement. Generally, it is completely absorbed by 70 days; however, loss of strength and absorption vary greatly. (https://emedicine.medscape.com/article/1127693-overview#a3)

Absorbable Suture Material Chromic gut is plain gut treated with chromium salts to slow absorption and decrease tissue reactivity by cross-linking the collagen. Its tensile strength is maintained for as long as 10-21 days, and complete absorption does not occur until at least day 90. This material is used in the closure of mucosal surfaces or as ligatures for blood vessels, among other uses.

Absorbable Suture Material Fast-absorbing gut is plain gut treated with heat to facilitate more rapid absorption. It was designed for percutaneous suturing and maintains its tensile strength for only 5-7 days. It is completely absorbed within 2-4 weeks. Fast-absorbing gut is useful for the percutaneous closure of facial wounds under low tension and for securing both split- and full-thickness skin grafts.

Absorbable Suture Material Polyglactin-Introduced in 1974, polyglactin was the second synthetic absorbable suture material available. The product is braided. Polyglactin 910 (Vicryl; Ethicon) is coated with Polyglactin 370, which facilitates knot tying and reduces tissue drag; however, this coating also reduces knot security and may require the use of extra throws.

Absorbable Suture Material Polyglactin retains 60% of its tensile strength at day 14 after implantation and only 8% of its original strength at day 28. It is completely hydrolyzed by 60-90 days. Tissue reactivity with polyglactin is low. Although used primarily as a buried suture, polyglactin has been used for percutaneous closures without adverse outcomes and with resultant cost savings. Polyglactin is available as a clear or violet suture.

Absorbable Suture Material Poliglecaprone (Monocryl; Ethicon) is a synthetic absorbable material introduced in 1993. Poliglecaprone is very pliable despite its monofilament nature, and, as a result, its ease of use and knot strength are excellent. Among all absorbable monofilament sutures, poliglecaprone has the highest tensile strength; however, only 20-30% of its strength is retained at day 14 after placement. Complete hydrolysis occurs by 90-120 days. Poliglecaprone is most useful as a buried suture in wounds in which prolonged dermal support is not essential. Similar to other monofilament sutures, poliglecaprone has minimal tissue reactivity. It is available as a clear material.

Non Absorbable Suture Material Silk was first widely used as a suture material in the 1890s. Although silk is considered a non absorbable material, it is gradually degraded in tissue over 2 years. Silk has excellent handling and knot-tying properties and is the standard to which all other suture materials are compared. Its knot security is high, tensile strength low, and tissue reactivity high. Suture removal can be difficult and painful because the braided material becomes infiltrated with cells and encrusted with debris while implanted in the skin.

Non Absorbable Suture Material Nylon was the first synthetic suture available, and it is the most commonly used non absorbable material in wound closure. It is available in both mono filamentous and braided forms. Nylon has a high tensile strength, and, although it is classified as non absorbable, it loses tensile strength when buried in tissue. Braided forms retain no tensile strength after being in tissue for 6 months, whereas mono filamentous forms retain as much as two thirds of their original strength after 11 years. Monofilament nylon is stiff; therefore, handling and tying are difficult and knot security is low. The suture also may cut easily through thin tissue.

Non Absorbable Suture Material Polypropylene (Prolene, Ethicon) is a monofilament synthetic suture that was introduced in 1962. Its tensile strength is lower than that of the other synthetic non absorbable sutures. Its handling, tying, and knot security are poor as a result of its stiff nature and high memory. An additional throw is needed for adequate knot security. A method to improve security is the use of thermocautery to fuse the knots or transform the ends into small beads. Tissue reactivity is extremely low for polypropylene, and, unlike nylon, gradual absorption does not occur if it is buried in tissue. As a result, polypropylene is an excellent choice for a buried suture for long-term dermal support.

Non Absorbable Suture Material Simple running suture Running sutures are useful for long wounds in which wound tension has been minimized with properly placed deep sutures and in which approximation of the wound edges is good. This type of suture may also be used to secure a split- or full- thickness skin graft. Theoretically, less scarring occurs with running sutures than with interrupted sutures because fewer knots are made with simple running sutures; however, the number of needle insertions remains the same. Both basting sutures and tie-over bolsters have been used to help secure skin grafts. Advantages of the simple running suture over simple interrupted sutures include quicker placement and more rapid reapproximation of wound edges. Disadvantages include possible crosshatching, the risk of dehiscence if the suture material ruptures, difficulty in making fine adjustments along the suture line, and puckering of the suture line when the stitches are placed in thin skin.

Types of Stitches Simple Interrupted Running Running Locked Vertical Mattress Horizontal Mattress

Types of Sutures Simple interrupted suture Compared with running (continuous) sutures, interrupted sutures are easy to place, have greater tensile strength, and have less potential for causing wound edema and impaired cutaneous circulation. Interrupted sutures also allow the surgeon to make adjustments as needed to properly align wound edges as the wound is sutured. Disadvantages of interrupted sutures include the length of time required for their placement and the greater risk of crosshatched marks (i.e., train tracks) across the suture line. The risk of crosshatching can be minimized by removing sutures early to prevent the development of suture tracks.

Simple Interrupted Suture

Types of Sutures Running locked suture Locked sutures have increased tensile strength; therefore, they are useful in wounds under moderate tension or in those requiring additional hemostasis because of oozing from the skin edges. Running locked sutures have an increased risk of impairing the microcirculation surrounding the wound, and they can cause tissue strangulation if placed too tightly. Therefore, this type of suture should be used only in areas with good vascularization. In particular, the running locked suture may be useful on the scalp or in the post auricular sulcus, especially when additional hemostasis is needed.

Running locked suture

Types of Sutures Vertical mattress suture A vertical mattress suture is especially useful in maximizing wound eversion, reducing dead space, and minimizing tension across the wound. One of the disadvantages of this suture is crosshatching. The risk of crosshatching is greater because of increased tension across the wound and the four entry and exit points of the stitch in the skin. The recommended time for removal of this suture is 5-7 days (before formation of epithelial suture tracks is complete) to reduce the risk of scarring. If the suture must be left in place longer, bolsters may be placed between the suture and the skin to minimize contact. The use of bolsters minimizes strangulation of the tissues when the wound swells in response to postoperative edema. Placing each stitch precisely and taking symmetric bites is especially important with this suture.

Vertical Mattress

Types of Sutures Horizontal mattress suture The horizontal mattress suture is useful for wounds under high tension because it provides strength and wound eversion. This suture may also be used as a stay stitch for temporary approximation of wound edges, allowing placement of simple interrupted or subcuticular stitches. The temporary stitches are removed after the tension is evenly distributed across the wound. Horizontal mattress sutures may be left in place for a few days if wound tension persists after placement of the remaining stitches. In areas of extremely high tension at risk for dehiscence, horizontal mattress sutures may be left in place even after removal of the superficial skin sutures. However, they have a high risk of producing suture marks if left in place for longer than 7 days.

Horizontal Mattress Suture

Knots The knot is the weakest portion of the suture. Its strength is defined by the force necessary to cause slippage. The 2 most commonly used types of knots in surgery are flat square knots and sliding knots. Flat square knots are considered more secure than sliding knots, whereas sliding knots allow for a tighter knot when tighter approximation of tissue is required. A surgeon’s knot is a square knot in which two knot throws are performed prior to tightening the knot. Although this initial throw adds no strength to the knot, it decreases the tendency of the wound to separate as the suture is tied.

Timing of Suture or Staple Removal WOUND LOCATION TIMING OF REMOVAL (DAYS) Face Three to five Scalp Seven to 10 Arms Seven to 10 Trunk 10 to 14 Legs 10 to 14 Hands or feet 10 to 14 Palms or soles 14 to 21 American Family Physician www.aafp.org/afp Volume 78, Number 8 ◆ October 15, 2008

Suture Sizes Size O: Largest Suture Size 2-O Size 3-O Size 4-O Skin: Foot Deep: Chest, Abdomen, Back Size 4-O Skin: Scalp, Chest, Abdomen, Foot, Extremity Deep: Scalp, Extremity, Foot Size 5-O Skin: Scalp, Brow, Oral, Chest, Abdomen, Hand, Penis Deep: Brow, Nose, Lip, Face, Hand Size 6-O Skin: Ear, Lid, Brow, Nose, Lip, Face, Penis Size 7-O: Smallest Suture Skin: Eyelid, Lip, Face

Types of Sutures for Certain Locations Mucosal Lacerations (mouth, Tongue or genitalia) Absorbable Suture: 3-0 or 4-0 Scalp, Torso (chest, back, Abdomen), Extremities Superficial Non absorbable Suture: 4-O or 5-O Deep Absorbable Suture: 3-O or 4-O Face, Eyebrow, Nose, Lip Superficial Non absorbable Suture: 6-O Deep Absorbable Suture: 5-O Ear, Eyelid Hand Superficial Non absorbable Suture: 5-O Foot or sole Superficial Non absorbable Suture: 3-O or 4-O Deep Absorbable Suture: 4-O Penis Superficial Non absorbable Suture: 5-O or 6-O