Sutures (O.R. Technique)

Definition:

• a suture is a piece of thread-like material used to stitch or approximate tissues, and hold the wound together until healing takes place.
• any strand of material used to ligate bleeders or used to approximate tissue.
• any materials used to sew, sick or hold tissue together until healing process occurs.

Purpose of Suture:

• to hold a wound together in good apposition until such time as the natural healing process is sufficiently well established to make the support from the suture material unnecessary and redundant.

Ligature or Tie – refers to a suture material that is tied around a blood vessel to occlude the lumen.

Two types of ligature or tie:

1. Free tie – is a stand of material that is handed or given the surgeon or assistant to ligate a vessel. This stand is not threaded on a needle.
2. Stick tie or suture ligature – the suture material is threaded either on a needle holder or on a right angle clamp before occluding a deep or large vessel.

Atraumatic Suture – a suture material prepared or manufactured with a needle attached to it. It is referred to as an eyeless needle or atraloc-swage on needle.

Strand – suture material prepared or manufactured without a needle attached to it.

Continuous Suture – a suturing technique wherein a surgeon start suturing at one point and ends at the other point without cutting the suture material. This may be referred to as a running stitch and also used to close the peritoneum and vessels because it provide a leakproof suture line.

Interrupted Suture – the suture is taken, tied and out separately. This technique is time consuming.

Subcuticular Suture – a continuous suture is placed beneath epithelial layer of skin in short lateral stitches. It leaves a minimal scar formation.

Buried Suture – a suture placed under the skin, buried either continuous or interrupted suture.

Burse String or Inverting Stitch – a continuous suture is used as a draw string method to invert the loose ends or edges of tissue and tied the close the lumen. (for example, stamp of the appendix.)

Traction Suture – is used to hold tissue out of the way during the operation.

Classification of Suture Material:

1. Absorbable Suture. An absorbable suture is made from material that can be absorbed (digested) by body cells and fluids. Rate of absorption depends on various factors, including type of body tissue, nutritional status of the patient, and the presence of infection. Absorbable suture is available prepackaged and pre-sterilized in various sizes graded by diameter and length. Sizes range from number 12-0, which is the finest, to number 5, which is the heaviest. The length ranges from 12 to 60 inches.

a. Plain gut. Plain indicates a surgical gut material that has not been treated to lengthen its absorption time in the tissue. This suture is absorbed more rapidly than treated suture.

b. Chromic gut. Chromic surgical gut has been treated with chromic oxide so that it will delay its rate of digestion or absorption.

c. Synthetic Absorbable Sutures

i. Polyglactin 910 (Vicryl).

ii. Polyglycolic Acid (Dexon).

iii. Polydioxanone (PDS).

2. Non-absorbable Suture. This suture material is not absorbed during the healing process. Non-absorbable suture becomes encapsulated (enclosed in a capsule) with tissue and remains in the body until it is removed or cast off. Silk, nylon, cotton, linen, polypropylene, and corrosion-resisting steel wire are examples of non-absorbable sutures. Sutures used for skin closure are usually removed before healing is complete.

Suture Sizes:

• Sutures are sized by the USP (United States Pharmacopoeia) scale
• The available sizes and diameters are:
• 6-0 = 0.07 mm
• 5-0 = 0.10 mm
• 4-0 = 0.15 mm
• 3-0 = 0.20 mm
• 2-0 = 0.30 mm
• 0 = 0.35 mm
• 1 = 0.40 mm
• 2 = 0.5 mm

Suture characteristics:

• Suture materials vary in their physical characteristics
• Monofilament sutures (e.g. polypropylene) are smooth
• The slide well in tissues but if handles inappropriately they can fracture
• Multifilament sutures (e.g. polyglactin) are braided
• They have a greater surface area
• They are easier to handle and knot well
• Some suture materials have a ‘memory’ (e.g. polypropylene)
• Return to former shape when tension is removed

Catgut

• Made from the submucosa of sheep gastrointestinal tract
• Broken down within about a week
• Chromic acid delays hydrolysis
• Even so it is destroyed before many wounds have healed

Silk

• Strong and handles well but induces strong tissue reaction
• Capillarity encourages infection causing suture sinuses and abscesses

Vicryl

• Tensile strength
• 65% @ 14 days
• 40% @ 21 days
• 10% @ 35 days
• Absorption complete by 70 days

Polydioxone

• Tensile strength
• 70% @ 14 days
• 50% @ 28 days
• 14% @ 56 days
• Absorption complete by 180 days

Specifications for Suture Materials:

1. It must be sterile
2. It must be uniform in tensile strength by size and material.
3. It must be hypoallergenic and less tissue reactive.
4. It must be safe on each type of tissue.
5. It must be secure and tight when knotted.
6. It must be appose and maintain the tied tissues together until it fully heal.

Source:
http://www.surgical-tutor.org.uk
http://www.wikipedia.org
Operating Room Technique Instructional Manual - 2nd Ed.