Suture materials & Techniques

1. Suture materials & Techniques Dr.Vinayakrishna.K Asst Professor Dept of OMFS YDC Deralakatte

2. Contents History Suture classification and selection Needles Suturing techniques

3. Ants In the tenth century BC, the ant was held over the wound until it seized the wound edges in its jaws. It was then decapitated and the ant's death grip kept the wound closed.

4. Thorns The thorn, used by African tribes to close tissue, was passed through the skin on either side of the wound. A strip of vegetable fibre was then wound around the edge in a figure eight.

5. Sterilised Catgut The tough membrane of sheep intestine was provided to the surgeon pre-sterilised and required threading through the eye of the needle before use.

6. Definitions SUTURE MATERIAL “A suture is a strand of material used to ligate vessels & re approximate lacerated/ incised tissue”. SUTURING “The act of sewing or bringing severed tissues in close approximation until the healing process provides the wound sufficient strength to with stand stress without the need for mechanical support”.

7. The Ideal Suture Minimal tissue reaction Smoothness - minimum tissue drag Low Capillarity Max tensile strength Ease of handling - Minimum memory Knot security Consistency of performance Predictable performance Cost effectiveness

8. Suture Classification and Selection

9. Suture Classification Natural or Synthetic (man made) Monofilament or Multifilament (braided) Absorbable or Non-Absorbable

10. Monofilaments: • Single strand • Resists harboring m-osms • Ties down smoothly Multifilaments: • Several filaments which are either braided/twisted • Good handling & tying characteristics

11. Suture Classification Monofilament Multifilament (braided)

12. Braided v Monofilament • Has capillary action • Increased infection risk • Less smooth passage • Less tensile strength • Better handling • Better knot security • No capillary action • Less infection risk • Smooth tissue passage • Higher tensile strength • Has memory • More throws required

13. CLASSIFICATION ABSORBABLE: Suture material that are digested by the body enzyme or are hydrolyzed by the tissue fluids NON ABSORBABLE: Sutures that cannot be digested by the tissue enzymes & are encapsulated. These can be natural or synthetic.

14. Absorbable Sutures • These are absorbed within the living tissue • Two main characteristics are: • Tensile strength retention • Absorption rate Maxon: Day 14: 75% Absorption: 180 days Caprosyn: Day 10: 30% Absorption: 56 days

15. Characteristics of Non-Absorbable Sutures • Permanent • Only used when long term support is required • Removed when used for skin (e.g. in A+E) • Tissue reaction generally low (except silk) • However silk, linen and even nylon will lose tensile strength over a period of time • True non-absorbable sutures include polyester, polyethylene, polybutester, polypropylene and steel

16. Suture Size USP (United States Pharmacopoeia) A+E 5..4..3..2..1..0..2/0..3/0..4/0..5/0..6/0..7/0..8/0..9/0..10/0..11/0 General Thick Thin

17. PHYSICAL PROPERTIES • Absorbable - Progressive loss of mass and/or volume of suture material; does not correlate with initial tensile strength • Breaking strength - Limit of tensile strength at which suture failure occurs • Capillarity - Extent to which absorbed fluid is transferred along the suture

18. Elasticity - Measure of the ability of the material to regain its original form and length after deformation • Fluid absorption - Ability to take up fluid after immersion • Knot-pull tensile strength - Breaking strength of knotted suture material (10-40% weaker after deformation by knot placement)

19. Knot strength - Amount of force necessary to cause a knot to slip (related to the coefficient of static friction and plasticity of a given material) • Memory - Inherent capability of suture to return to or maintain its original gross shape (related to elasticity, plasticity, and diameter) • Plasticity - Measure of the ability to deform without breaking and to maintain a new form after relief of the deforming force

20. BIOLOGIC RESPONSE • The 1st response is invasion of the tissue site by the neutrophils. • If uncomplicated by infection or trauma the acute cellular tissue response to suture changes in about 3 days. • Neutrophils replaced by monocytes, lymphocytes, plasma cells etc. • Small vessels infiltrate the area, eventually fibroblasts & connective tissue cells proliferate.

21. Assuming the same technique, tissue & other relative factors the tissue response is relatively same for the first 5 – 7 days. • Plain catgut elicits a more intense response with macrophage & neutrophils while all the nonresorbable sutures show a less intense relatively acellular response. • All sutures passing thru the mucus membrane or skin provides a WICK or passage thru which bacteria can track down & gain access to the underlying tissues.

22. Longer the suture remains, deeper the epithelial invasion of underlying tissue. When suture is removed epithelial tract remains. • These cells may eventually disappear or remain to form keratin & epithelial inclusion cyst. • Epithelial pathway may also result in the typical `RAIL ROAD SCAR` formation. • Monofilament decrease the incidence of infection where as multifilament braided sutures allow the penetration of bacteria

23. Prolene, steel elicit the least inflammatory response while nylon, polyester, cotton & silk cause increased tissue response respectively.

24. Natural • COLLAGEN: This comes from the submucosa of sheep intestine or the serosa of beef intestine. • CARGILE MEMBRANE: Is a thin sheet of tissue obtained from the submucosal layer of the caecum of ox. It was formerly used to cover surfaces of peritoneum, Pleura etc when they were removed. It is used prevent adhesion’s in abdominal surgery, for isolating ligation’s. It is infrequently used today & is replaced by prolene Mesh.

25. FASCIALATA: It is obtained from the thigh muscles of beef cattle. Formerly it was used in the repair of hernias. Today it is used off & on for the drooping of the upper eyelid & sometimes for facial palsy.

26. Surgical gut, plain: Tensile strength is maintained for 7-10 days post implantation (variable with individual patient characteristics). Absorption is complete within 70 days. This type of suture is used for (1) repairing rapidly healing tissues that require minimal support, (2) ligating superficial blood vessels, and (3) suturing subcutaneous fatty tissue. • Surgical gut, fast-absorbing: This type of suture is indicated for epidermal use (required only for 5-7 days) and is not recommended for internal use.

27. Surgical gut, chromic (treated with chromium salt): Tensile strength is maintained for 10-14 days. The absorption rate is slowed by chromium salt (90 d). This type of suture may be used in the presence of infection. Tissue reaction is due to the noncollagenous material present in these sutures. Also, patient factors affect rates of absorption and make tensile strength somewhat unpredictable.

28. Synthetic • These are Chemical polymers and are absorbed by hydrolysis and cause a lesser degree of tissue reaction following placement.

29. POLYGLACTIN 910 (VICRYL) • Braided multifilament suture coated with a copolymer of lactide and glycolide (polyglactin 370). The water-repelling quality of lactide slows loss of tensile strength, and the bulkiness of lactide leads to rapid absorption of suture mass once tensile strength is lost. The suture is also coated with calcium stearate, which permits easy tissue passage, precise knot placement, and smooth tie-down. Tensile strength is approximately 65% at 14 days. Absorption is minimal for 40 days and complete in 56-70 days. These sutures cause only minimal tissue reaction and may be used in the presence of infection. Vicryl sutures are used in general soft tissue approximation and vessel ligation.

30. Another similar suture material is made from polyglycolic acid and coated with polycaprolate (Dexon II). This material has a similar tensile strength and absorption profile. • Dexon can be self colored or dyed green & can be uncoated, coated with a lubricant to reduce coefficient of friction. • Dexon absorbs by 90 days

31. POLYDIOXANONE (PDS) Synthetic, monofilament, absorbable suture made from paradioxaninone & marketed for its prolonged Tensile strength. PDS takes 56 days to lose its Tensile strength & 180 days to absorb. These materials’s also elicits a minimal Tissue reaction & is absorbed by hydrolysis. It is produced in a Translucent & violet dyed form. PDS retains 74 % of its original Tensile strength at 2wks, 58% at 4wks and 41% at 6wks. Minimal foreign body reaction occurs. PDS has decreased affinity in harboring bacterial organisms but its intrinsic stiffness is a disadvantage. This can be used in the presence of infection.

32. POLYTRIMETHYLENE CARBONATE (MAXON) • Synthetic Monofilament absorbable material developed to combine the excellent Tensile strength & retention properties of PDS with improved handling properties Average strength retention of 81 % at 14 days to 30% at 42 days. Complete absorption by hydrolysis takes place between 180 & 210 days with minimal tissue reaction. Its improved strength & handling makes it preferable absorbable suture material.

33. Rate of Absorption of Absorbable sutures is dependent on a. Tissue layer b. Vascularity c. Enzymes d. General condition of patient.

34. NON ABSORBABLE SUTURES

35. United States Pharmacopoeia classification • Class I - Silk or synthetic fibers of monofilament, twisted, or braided construction • Class II - Cotton or linen fibers or coated natural or synthetic fibers in which the coating contributes to suture thickness without adding strength • Class III - Metal wire of monofilament or multifilament construction

36. SILK Silk is derived from the cocoon of the silkworm larvae It is basically a protein like keratin of hair and skin and is covered initially by an albuminous layer which is removed by a process of DEGUMMING prior to making of sutures. The suture is braided round a core and coated with wax to reduce capillarity action. This material has high tensile strength, which is probably totally lost after 2 years. Tissue reaction is greater to silk. The cellular reaction is mainly polymorphonuclear and is less in intensity than surgical gut. Encapsulation of the silk with a fibrous capsule usually occurs in 14-21 days.

37. NYLON Is synthetic, mono/multifilament, non- absorbable suture, available in braided/ monofilament form. It is a polyamide polymer, degrades at a rate of 15-20% per year and has a good tissue response. Nylon possesses the property of “Memory”. Multiple square knots are necessary to maintain the tie Nylon has good tensile strength but ranks below to that of steel, Dacron and polyglycolic acid. Because of its stiffness, large knot is required and a tendency to tear thru non-keratinized tissue, nylon is not frequently used intra-orally.

38. SURGICAL COTTON • Is natural, multifilament, non-absorbable suture derived from the hairs of the seed of cotton plant. The suture is made from noncontiguous natural fibers of cotton, combined into yarns and then twisted into plies. Its strength is similar to silk but handling characteristics are inferior to silk.

39. LINEN Is made from flax and is cellular material. It is twisted to form a fiber to make a suture. Tissue reaction is similar to silk and the material knots well. Linen is stronger than silk. It is very extensively used for tying pedicles and ligatures.

40. METAL Stainless steel or tantalum sutures are either monofilament or braided, strongest and produce most secure knot than any suture materials. Has an enviable reputation among non-absorbable sutures for strength and low tissue reaction. Tissue tolerance is good but less than that of found with nylon, Dacron or propylene. Undergoes degradation through corrosion, which releases ions and is known to cause tissue reaction (slow process). Metallic sutures are stiff and do not confirm to the suture pathway during host movement. The resultant irritation may produce tissue damage and increased susceptibility to infection.

41. POLYPROPYLENE (PROLENE) • It is a monofilament and is chemically extruded from a purified and dyed polymer of propylene. Has extremely low tissue reactivity. It can extend up to 30% before breaking Useful inpostoperative swelling has low co efficient of friction and slides thru tissues readily with low adherence to tissue- which is ideal for running a subcuticular stitch because it tends to slide smoothly at time of suture removal. It is sterilized by Ethylene oxide.

42. Needle selection

43. Classification of Surgical Needles According to its eye: • Eyeless needles. • Needles with eye. According to shape: • Straight needles. • Curved needles. According to cutting edge: • Round body needles. • Cutting needles • Conventional cutting needles. • Reverse cutting needles.According to its tip. • Triangular tipped needles. • Round tipped needles. • Blunt point needles. • Others: • Spatula needles. • Micropoint needles.

45. Anatomy of needle • 3 types of needle eyes a. Closed b. Split (French) c. Swaged Closed and split less desirable because the junction of the needle and suture is often enlarged. Increased risk of tissue trauma and must be threaded, time consuming

46. Needle body: Circle • Points - Tapered - Blunt - Cutting • In dentoalveolar surgery cutting needles preferred because of thickness, resilience and resistance of gingiva and oral mucosa.

47. Needle Curvature

48. Needle point Geometry

49. Needle Point Geometry

50. SUTURING TECHNIQUES