Wound closure, suture material, technique and alternative to suture

How surgical wound should be closed with suture and it's techniques. What are the alternative to the suture used in the modern world.

1. Wound closure, Suture material, Technique and alternative to suture By : Dr. Kapil Vishvakarama

2. WOUND CLOSURE Suturing of any incision and wound need to take in consideration the site and tissue involved, and the technique should be chosen accordingly There is no ideal wound closure technique and ideal suture for all situations Therefore correct choice of suture technique and suture material is vital and should never compensate for inadequate operative technique. For any wound to heal well there should be good blood supply and no tension on closure

3. Clean uninfected wounds with good blood supply heals with primary intention and therefore closure simply requires accurate apposition of the wound edges. If a wound left open it heals with secondary intention through formation of the granulation tissue Delayed primary closure or tertiary intention is utilized when there is a high probability of wound being infected, skin grafting is another form of tertiary intention healing

4. While choosing a suture material there are certain specific requirement depending upon the tissue to be sutured Vascular anastomosis requires smooth, non-absorbable, non-elastic material Biliary anastomosis requires an absorbable material that will not promote tissue reaction or stone formation. When using absorbable material the time for which wound support is required and maintained will vary according to the tissue in which it is inserted.

5. Suture characteristics There are five characteristics of the suture that need to consider Physical structure Strength Tensile behavior Absorbability Biological behavior

6. Physical structure Monofilament Multifilament

7. Monofilament Smooth No sawing action Difficult to knot Damaged by gripping it with needle holder or forceps Multifilament Braided Sawing action Easy to knot Having capillary action and interstices where bacteria can lodge leading to persistent infection or sinuses Silicone coating is done to make it smooth

8. Strength Depends upon Constituent material Thickness Handling Size of suture material Metric ( EurPh ) Range of diameter (mm) USP (old) 1 0.100-0.149 5-0 1.5 0.150-0.199 4-0 2 0.200-0.249 3-0 3 0.300-0.349 2-0 3.5 0.350-0.399 4 0.400-0.499 1 5 0.500-0.599 2

9. The tensile strength of a suture can be expressed as force require to break it when pulling two ends apart Absorbable sutures shows a decay of its strength with passage of time However, even non-absorbable suture may degrade with time except synthetic origin such as polypropylene Non-absorbable material of biological origin such as silk will definitely fragment with time and should never be used in vascular surgeries

10. Tensile behavior Suture material behave differently depending upon their flexibility and deformability Suture material can be ‘Elastic’ or ‘Plastic’ Some are deformable in which circular cross sectional area is converted into oval shaped Many synthetic material demonstrated memory so that they keep curling up in the shape they adopted in the package – A sharp gentle pull helps to diminish the memory Greater the memory, lesser the knot security Suture loses its 50% tensile strength at the knot

11. Absorbability This property must be consider when choosing suture material for specific wound closure and anastomosis Suture material Absorbable Non-absorbable Catgut Chromic Catgut Polyglactin Polyglyconate Polyglycolic acid Polydioxanone Polyglycaprone Silk Linen Surgical steel Nylon Polyester Polybutester Polypropylene

12. Suture used in biliary and urinary tract should be absorbable and vascular anastomosis requires a non-absorbable and smooth material Non-absorbable material is used where strength is required as in artificial graft or prosthesis eg. Polypropylene monofilament

13. Biological behavior It depends upon the suture constituent raw material Biological and natural sutures, such as catgut are proteolyzed which is unpredictable and can cause local irritation Synthetic polymers are hydrolyzed and there disappearance in the tissue is more predictable Presence of pus, urine or faeces influences the final result

14. Barbed suture These sutures have unidirectional or bidirectional barbs that secure the suture in tissue.

15. Non-absorbable suture material Suture Types Raw material Tensile strength Absorption rate Tissue reaction Contraindication Frequent uses Silk Braided, multifilament Natural protein Loses 20% when wet; 80-100% lost by 6 months absorbed slowly over 1-2 years Moderate to high Not to use with vascular prosthesis For securing drains externally Linen Twisted Long staple flax fibres Stronger when wet Loses 50% at 6 months Non-absorbable Moderate Not advised for use with prosthesis Ligation and suturing in GI surgery Surgical steel Mono or multifilament An alloy of iron, nickel and chromium Infinite Non-absorbable Minimal Should not be used in conjoint with prosthesis if different material Closure of sternotomy wounds Nylon Mono or braided multifilament Polyamide polymer Loses 15-20% per year Degrades at 15-20 % per year Low None Skin closure, abdominal wall mass closure, hernia repair, platic surgery, neurosurgery, micro and ophthalmic surgery

16. Suture Types Raw material Tensile strength Absorption rate Tissue reaction Contraindication Frequent uses Polyester Mono or braided, dyed or undyed Polyester Infinite Non-absorbable Low None Cardiovascular, ophthalmic, plastic and general surgery Polybutester Monofilament, dyed or undyed Polybutylene terephthalate Infinite Non- absorbale Low None Exabits a degree of elasticity, favored use in plastic surgery Polypropylene Monofilament, dyed or undyed Polymer of propylene Infinite Non-absorbable Low None Cardiovascular, plastic, ophthalmic, general surgical subcuticular skin closure

17. Absorbable suture materials Suture Types Raw material Tensile strength Absorption rate Tissue reaction Contraindication Frequent uses Catgut Plain Collagen derived from healthy sheep or cattle Lost within 7-10 days Phagocytosis and enzymatic degradation within 7-10 days High Not for use in tissues that heals slowely Ligate superficial vessels, Other tissue that heal rapidly Catgut Chromic Collagen derived tanned with chromium salts Lost within 21-28 days Phagocytosis and enzymatic degradation within 90 days Moderate As for plain catgut As of plain catgut Polyglactin Braided multifilament Copolymer of lactide and glycolide in ration of 90:10; coated with polyglactin and calcium stearate Approximately 60% remains at 2 weeks Hydrolysis minimal until 5-6 week. Complete absorption 60-90 days Mild Not advised for use in tissue that require prolonged approximation under stress General surgical use eg. Gut anastomosis, vascular ligation

18. Suture Types Raw material Tensile strength Absorption rate Tissue reaction Contraindication Frequent uses Polyglyconate Monofilament, Dyed or undyed Copolymer of glycolic acid and triethylene carbonate Approximately 70% remains at 2 weeks Hydrolysis minimal until 8-9 week. Complete absorption by 180- days Mild Not advised for use in tissues that require prolonged approximation under stress As an alternative to vicryl and PDS Polyglycolic acid Braided multifilament, dyes or undyed, coated or uncoated Polymer of polyglycolic acid Approximately 40% at 1 week Hydrolysis minimal at 2 weeks, significant at 4 weeks, complete absorbtion at 60-90 days Minimal Not advised for use in tissues that require prolonged approximation under stress Particular where slightly longer wound support is required Polydioxanone (PDS) Monofilament, dyed or undyed Polyester polymer Approximately 70% remains at 2 weeks Hydrolysis minimal at 90 days, Complete absorption at 180 days Mild Not for use in association with heart valve or synthetic grafts Particular where slightly longer wound support is required

19. Suture Types Raw material Tensile strength Absorption rate Tissue reaction Contraindication Frequent uses Polyglycaprone Monofilament Copolymer of glycolite and caprolactone 21 days maximum 90-120 days Mild No use for extended support Subcuticular in skin, ligation, gastrointestinal and muscular surgery

20. Suture techniques There are four frequently used suture techniques Interrupted sutures Continuous sutures Mattress sutures Subcuticular sutures

21. Interrupted sutures It requires the needle to be inserted at the right angles on the incision and then pass through both aspects of the suture line and exits again at right angle. Needle should be rotated through the tissue

22. The distance from the entry point of the needle to the edge of the wound should be approximately the same as the depth of the tissue being sutured. Each successive suture should be placed twice the distance apart. In linear wound it is easier to insert the middle suture first and then to complete the closure by successively inserting sutures.

23. Continuous sutures First suture is inserted same as interrupted suture, but the rest of the sutures are inserted in a continuous manner until the end of the wound. Each throw of the continuous suture should be inserted at the right angle to the wound, by doing this externally observed suture material will usually lie diagonal to the axis of the wound. It is important to keeping the suture at the same tension in order to avoid either purse stringing the wound or leaving the suture material too slack. At the far end of the wound suture line should be secured either by Aberdeen knot or trying the free end to the loop of the last suture to be inserted.

24. Mattress sutures This suture may be either vertical or horizontal and tend to be produce either inversion and eversion of the wound edges. The initial suture is inserted same as that of interrupted suture, but then the needle moves either vertically or horizontally and traverses both edges of the wound once again. These sutures are very useful in producing accurate approximation of the wound edges, especially when the edges to be anastomosed are irregular in depth or disposition. Variation of mattress sutures are: Figure of 8 and half buried suture

25. Vertical Mattress Horizontal Mattress

26. Subcuticular sutures This technique is used in skin where a cosmetic appearance is important and where skin edges may be approximated easily. Suture material can be used either absorbable or non-absorbable. For non-absorbable suture, the end may secure by a collar and bead, or tied loosely over the wound For absorbable suture, the end may secure using a buried knot. Small bites of the subcuticular tissue are taken on alternate sites of the wound and then gently pulled together, thus approximating the wound edges without the risk of cross-hatched marking of interrupted sutures.

27. Others sutures techniques are Simple buried suture Simple running locking suture

28. Needles In the past, needles have an eye in them and suture material had to be loaded into them. Currently, needles are eye-less or atraumatic with suture material embedded with in the shank of the needle. Needle has three main parts: Shank Body Point

29. The needle should be grasped by the needle holder approximately one third to one-half of the way back from the rear of the needle, avoiding both shank and the point. The needle should never be grasped nearer than one-third of the way back from the rear of the needle. The body of the needle is either round, triangular or flattened. Round body needle gradually taper to the point while triangular needles have cutting edges along all the sides.

30. Conventional cutting needles has there cutting edge facing inside of the needle’s curvature. Reverse cutting needles has there cutting edge facing outside of the needle’s curvature.

31. Round bodied needle are designed to separate tissue fibres rather than cut through them and commonly used in intestinal and cardiovascular surgeries. Cutting needles are used where tough or dense tissue needs to be sutured, such as skin and fascia. Blunt ended needles are now being advocated in certain situation such as closure of the abdominal wall in order to diminish the risk of needle stick injuries.

32. The choice of the needle shape tends to be directed by the accessibility of the tissue to be sutured. If operative space is more confined, more curved needle should be used. Needle holder should be used in all cases to reduce the risk of needle stick injuries Half circle needles are commonly used in gastrointestinal tract

33. J-shaped, quarter circle and compound curvature needles are used in special situations such as the vagina, eye and oral cavity, respectively.

34. Knotting techniques The general principles behind knot tying includes: The knot must be tied firmly, without strangulating the tissue The knot must be unable to slip or unravel The knot must be as small as possible to minimize the amount of foreign material. The knot must be tightened without exerting any tension or pressure on the tissue being ligated.

35. During tying the suture material must not be ‘sawed’ as this weakens the thread The suture material must be laid square during tying When tying an instrument knot, the thread should only be grasped at the free end. The standard surgical knot is the reef knot with a third throw for security. Monofilament sutures required in vascular surgeries required six to eight throws for security A granny knot involves two throws of the same type of throws and is a slip knot – used to achieve right tension, but must be followed by a standard reef knot to ensure security

36. When added security is required, a surgeon’s knot using a two throws technique is advisable to prevent slippage When using continuous suture technique, an Aberdeen knot may be used for the final knot. When the suture is cut after knotting, the ends should be left about 1-2 mm long to prevent unraveling

37. Types of knots

38. Alternatives to sutures Skin adhesive tapes Tissue glue Laparoscopic wound closure Staples

39. Skin adhesive strips For the skin, self adhesive tapes or stripes may be used where there is no tension and not too much moisture, such as after a wide excision of a breast lump. These may also used to minimize spreading of a scar. Adhesive polyurethane films, such as Opsite , Tegaderm or Bioclusive , may provide a similar benefit, while such transparent dressing also allow wound inspection and may protect against cross-infections.

40. Tissue glue It is based upon a solution of n-butyl-2-cyanoacrylate monomer. When it is applied to a wound, it polymerizes to form a firm adhesive bond, but the wound does need to be clean, dry, with near perfect hemostasis and under no tension. Although it is relative expensive, easy to use, does not delay wound healing and is associated with relative low infection rate. Other tissue glue involves fibrin which works on the principles of converting fibrinogen to fibrin by thrombin with crosslinking by factor XIII, and the addition of aprotinin to slow the breaking up the fibrin network by plasmin

41. This is used in achieving hemostasis in the liver and spleen, for Dural tears, in ear, nose and throat and ophthalmic surgery, to attach skin grafts and also to prevent haemoserous collection under flaps

42. Laparoscopic wound closure Laparoscopic wound are generally 3-12 mm in length. Skin closure can be carried out with sutures, using curved or straight needles, or glue and can be further secured with adhesive stripes.

43. Staples Mechanical stapling devices were first used successfully by Hümér Hültl in Hungary in 1908 to close the stomach after resection. Today it is wide range of mechanical devices with linear, side-to-side and end-to-end stapling devices that can be used both in the open surgery or laparoscopically.

44. Stapling devices In gastrointestinal tract, stapling devices tend to apply two row of staples, offset in relation to each other, to produce sound anastomosis. Many of them simultaneously divide the bowel or tissue that has been stapled while other devices merely insert the staple and the bowel has to be divided separately

45. End-to-end anastomosis Circular stapling devices allow tubes to be joined together, and such instruments are in common use in the esophagus and low rectum. The detached stapling head is introduced into one end of the bowel and secured by purse string suture. The body of the device is then inserted into the other end of the bowel, either via the rectum for low rectal anastomosis or via enterotomy for an esophago-jejunostomy and the shaft is either extended through a small opening in the bowel wall or secured by further purse string suture.

46. Head is reattached to the shaft and the two ends approximated. Once the device is fully close, as indicated by the green indicator in the window, the device is fired and after unwinding, the stapler is gently withdrawn. It is important to assess the integrity of the anastomosis by examining the ‘doughnuts’ of the tissue. It is essential that no extraneous tissue is allowed to become interposed between the two bowel walls on closing the stapler.

47. Transverse anastomosis These instruments, which came in different sizes, simply provide two row of staples for a single transverse anastomosis. Useful in closing bowel ends and the larger sizes has been used to create gastric tubes and gastric partitioning. Bowel should be divided before the instrument is reopened after firing, as the instrument is designed with a ridge along which to pass a scalpel to ensure that the cuff of bowel that remains adjacent to the staple line is of the correct length.

48. Intraluminal anastomosis These instruments have two limbs which can be detached. Each limb is introduced into a loop of bowel, the limb reassembled and the device closed. On firing, two rows of staples are inserted either side of the divided bowel, the division occurring by means of a built-in blade that is activated at the same time as the insertion of the staples. Such an instrument may be used in gastro-jejunostomy or jejuno-jejunostomy and is used in ileal pouch formation.

49. Laparoscopic stapling devices Since the early 1990s, increasingly complex surgical procedures have been performed laparoscopically Many of the intestinal stapling devices are now adapted to be inserted through trocars during laparoscopic surgery, the principles of function are identical to their open surgical equivalent Linear cutting staplers allow bowel and blood vessels to be sealed and divided. Linear and circular staplers also allow intracorporeal anastomosis to be performed.

50. Thank you