Suturing
Suturing: is defined as sewing together two structures or tissues using suture threaded on a needle. Suturing of the surgical wound is necessary, aiming at holding a flap over the wound, re-approximating the wound edges, If the space between the two wound edges is minimal, wound healing will be rapid and complete. If tears or excessive trauma to the wound edges occur, wound healing will be by secondary intention. , protecting underlying tissues from infection or other irritating factors,protecting underlying tissues from infection or other irritating factors, and preventing postoperative hemorrhage. Suturing may also aid in the following:
• for ligation of a large vessel
• For laceration of soft tissues in general
• In cases of severe hemorrhage where the suture holds the hemostatic plug in place
• for stabilization of the rubber drain at the site of incision
• For immobilization of pedicle flaps in their new position, etc.
• Sutures help hold a soft tissue flap over bone. This is an important function because bone that is not covered with soft tissue becomes non vital and requires an excessively long time to heal.• Sutures may aid in maintaining a blood clot in the alveolar socket.
SURGICAL NEEDLES :These are sharp pointed instruments used for guiding the thread for suturing or passing a ligature around a vessel. Parts of a Needle The parts of a needle are tip, body and eye The eye is the weakest part of the needle. Hence, needle should never be held near its eye.
Classification :
The needles can be classified as follows:On the Basis of its Eye
Eyeless needles (atraumatic)
Needles with eye (traumatic)
Eyeless needle has suture swaged to
it at the blunt end of the needle.
Hence, it causes less trauma.
Straight needles are used for suturing superficial tissues (skin, fascia) without using needle holder. These are rarely used these days.
On the Basis of its Edge
• Round body needle
•.Cutting needle
•Reverse cutting needle
• Taper cut needle
Round body needle has a rounded tip that separates the tissue fibers rather than cutting them. It is used in suturing of soft tissues (vessels, intestines).
Cutting needle has two opposing cutting edges on outside and third edge on inside curve of the needle. Thus, its point looks triangular in cross section. It is used for suturing tough tissues (skin, fascia).
Reverse cutting needle has triangular edge like cutting needle. But the two opposing cutting edges are on inside and third edge on outside curve of the needle. This improves the strength of the needle and increases its resistance to bending in tough tissues
Taper cut needle has reverse cutting tip limited to the point of the needle which then tapers out to merge smoothly into round cross-section. Thus, it combines the initial penetration of reverse cutting with minimized trauma of round body needle
The suture needle usually used in the mouth is a small three-eighths to one-half circle with a reverse cutting edge. The cutting edge helps the needle pass through the tough muco-periosteal flap tissue. Needle sizes and shapes have been assigned numbers.
SUTURE MATERIALS The ideal suture,
• Uniform diameter and uniform tensile strength.
• Adequate tensile strength till tissue healing is complete.
• It should produce secure knots without cutting or slipping.
• It should have easy handling.
• Minimum tissue reaction.
• It should not allow bacterial lodgment.
• It should be non-allergic.
• 8. It should be less expensive and freely available
Classification The suture materials are classified as follows:
1. Absorbable: The sutures are digested by tissue enzymes and removed by phagocytosis. These are of two types:A. Natural Catgut Kangaroo tendon , Beef tendon.
B. Synthetic
Polyglactin (Vicryl),
Polyglycaprone (Monocryl)
Polyglycolic acid (Dexon-S)
Polydioxinone (PDS)
2. Non-absorbable:
The sutures remain in the body. These are of three types:• Natural :
Silk
Cotton
• Synthetic:
Polyamide
Polyester
Polypropylene
• Metals Stainless steel ,Silver wire Titanium
The suture material may be monofilament (prolene) or polyfilament (silk). The polyfilament suture may be twisted or braided. The advantage of monofilament suture is that it does not allow the bacterial lodgement and thus can be used in presence of infection.
However, its disadvantage is that knots slip in monofilament suture due to its plain surface.
advantage of polyfilament suture has good knotting property but the its disadvantage it allows bacteria to lodge in its fibers.
Size of Sutures
The size or diameter of suture is based on United States Pharmacopedia (USP). This system used ‘0’ size as baseline.As size decreased below ‘0’,the numbers are added with zero, e.g., 5-0 or 00000 suture is smaller in diameter than 4-0 or 0000 suture.
As suture diameter increases above ‘0’, numbers are assigned to the suture size, e.g. 1, 2, 3, 4, are increasing diameters of the suture.
Principles for Selecting Sutures
• Slow healing tissues like skin and fascia should be sutured with non absorbable sutures.• Rapidly healing tissues like muscles, intestines should be sutured with absorbable sutures.
• When cosmetic effect is important, use monofilament, non absorbable sutures of small size (e.g. 3-0 prolene). It has minimal tissue reaction. On the other hand, absorbable sutures (e.g. catgut) elicit severe tissue reaction and scar formation.
4. In presence of infection, use monofilament suture as it prevents bacterial lodgment.
5. In malnourished patient, healing is delayed. Hence, use non absorbable suture so that tissues are kept in approximation for longer period.6. For anastomosis of ducts (submandibular duct, parotid duct, common bile duct), always use absorbable sutures. In such situation, non absorbable suture will act as a nidus for precipitation of salts leading to stone formation.
The principles of suturing:
1. Needle should be grasped at approximately 1/3rd the distance from the eye and 2/3rd from the point.2. The needle should enter the tissues perpendicular to the tissue surface.
3. The needle should be passed through the tissues along its curve.
4. The needle always passes from the movable tissue to fixed tissue.
5. The needle always passes through the thinner tissue to the thicker tissues.6. The needle always passes from the deeper tissue to superficial tissue.
7. Tissues must never be closed under tension.
8. The knot should never lie on the incision line.
9. Sutures on the skin of the face are usually removed in 5 days and intra oral sutures in 7 days.
Suturing Techniques:
Interrupted suturing:It is used for closure of skin wounds. Infected areas are also closed with widely spaced interrupted sutures so that pus and exudates can be drained from in between sutures. Its advantage is that if one or two sutures are removed, the remaining wound does not gape. Its disadvantage is that it is time consuming and requires more suture material.
it may be used in all surgical procedures of the mouth. The needle enters 2–3 mm away from the margin of the flap (mobile tissue) and exits at the same distance on the opposite side. The two ends of the suture are then tied in a knot and are cut 0.8 cm above the knot.( Reef Knot It is the most commonly used knot and has the advantage that it does not slip )
Continuous Suture:
This is usually used for the suturing of wounds that are superficial but long, e.g., for re-contouring of the alveolar ridge in the maxilla and mandible.
Mattress Suture:
This is a special type of suture and is described as horizontal (interrupted and continuous) and vertical . It is indicated in cases where strong and secure re-approximation of wound margins is required.The vertical suture may be used for deep incisions, while the horizontal suture is used in cases which require limiting or closure of soft tissues over osseous cavities, e.g., post extraction tooth sockets.
