Suturing

Shape:

• 1/4 circle: ophthalmic and microsurgery
• 3/8 circle: general - skin
• 1/2 circle: general - fascia, vessels, GIT
• 5/8 circle ('J'): vascular and 'cavities'
• Straight: wound closure - now discouraged
• J: deep cavities

Size:

• Chord length - the linear distance from the point of the curved needle to the swage
• Needle length - distance measured along the needle from the point to the swage (this is what you normally get on the packaging)

Tip:

• Cutting/reverse cutting: cut through tissue to make an entrance point, so should be used on tougher tissues - periosteum, skin, tendons, sclera
  • Conventional cutting cuts upwards, along the inside of the curve. There is a risk of tear-out, so should be avoided for delicate tissues.
  • Reverse cutting has the cutting edge on the outside. Better for tendon sheath and skin.
• Taperpoint: viscera/most fascia/blood vessels
  • CT1: 36mm
  • CT2: 26mm
• Tapercut - like taperpoint but for denser tissue
• Blunt - for fascia
• Round-bodied - delicate tissue - sharp point with smooth shaft
• Mostly, the needle is joined or 'swaged' to the thread - referred to as 'atraumatic' needle because the hole is as small as possible

Materials

• Monofilament - less tissue reaction, less infection, less scarring
• Braided - can harbour infection, more likely to catch or cut out

• Nylon (Ethilon/polyamide) - usually monofilament. Poor handling/knotting. Ensure knots are tied square to avoid slippage. Remove memory prior to use. Breaks down very slowly. 6 throws. Handles better when wet.
• Silk - easy handling, secure knots, rare slippage. Low tensile strength. Rougher on tissues, so hurts on removal. Nidus for infection. Do produce an inflammatory reaction. 3 throws only required. Loses tensile strength at 1 year and disappears after 2 years.
• Polypropylene - prolene - non-absorbable, non-reactive. 6 throws. Can be used for bowel anastomosis. Biologically inert.  Expensive.
• Polydioxanone - PDS. Synthetic, monofilament, absorbable. Minimal tissue reaction. Hydrolysis starts at 90 days, complete at 6 months. Needs four throws to knot securely. Maintains strength in the presence of infection or exposure to harsh substances such as urine, bile and pancreatic juice.
• Polyglactin 910 (vicryl). Synthetic, multifilament, absorbable. Braided. Absorption commences 20-30 days, complete by 60-90 days, loses 50% of tensile strength within 3 weeks. Minor inflammatory reaction.
  • Standard Vicryl - coated with polyglactin 370 and calcium stearate, to reduce bacterial adherence, improve handling and decrease resistance
  • Vicryl Plus - also coated with the antiseptic triclosan - has been shown to reduce surgical site infections
  • Vicryl rapide - coated polyglactin 910 (lower molecular weight coating than standard Vicryl) - strength retention for 7-10 days, complete absorption 40-60 days, but lower tensile strength than normal Vicryl. Mucosa and skin (falls out on its own after a week or so).
• Poligecaptone 25 (Monocryl, kaprosyn). Synthetic, monofilament, absorbable. Little tissue reaction, great handling. Fully absorbed 90-120 days. All tensile strength lost by 21 days.
  • Monocryl - poligecaptone 25 with a lubricant coating. Comes undyed or purple. Available as a Plus version, coated with triclosan.
• Ethibond (braided polyester coated with polybutylate). Non-absorbable. Expensive. Strong.
• TiCron (braided polyethylene coated with silicone)

Suture sizes

• 1
• 0 (1/0)
• 2/0
• 3/0
• 4/0
• 5/0

Knots:

• Surgeon's knot is useful as a first throw with synthetic monofilaments
• 3-1-2 technique can be helpful in preventing slipping for heavy monofilament sutures such as 0 or 1 prolene
• Two-handed technique is suggested for deep or poorly-accessible locations
  • Advantage is that the two threads are in control the whole time - makes it easier to maintain tension
  • Can do a double-throw to start with
• One-handed technique is the simpler technique I first learnt (called one-handed since the right hand only acts as an anchor)

Simple everting skin suture

• To evert the skin more, make the deeper portion of the bite wider than the superficial portion

Vertical mattress (Stewart) suture

• Guarantees eversion
• Don't need to tie with excessive tension

Connell, Cushing, Lembert, Halsted, seromuscular sutures - see 'anastomosis' topic

Continuous locked stitch

Whip stitch

• Out to in, out to in, out to in, etc
• Quick and easy

Staples

• 5-10mm apart, depending on thickness of skin and underlying structures

Pulley suture (good for tensioning difficult wounds)

1. In 3mm from wound on side A
2. Out 10mm from wound on side B
3. In 10mm from wound on side A
4. Out 3mm from wound on side B
5. Hence tie between the two 3mm points

Cross-stitch (good for closing circular wounds e.g. punch biopsy)

Three-point corner suture (for closing triangles)