ANSWERS

Note: Those questions marked with an asterisk are not essential for NVQ level 3, but may be useful for further study or Diploma candidates.

1. List 5 ways in which suture materials are categorised.
   • Absorbable or non-absorbable.
   • Natural or manmade.
   • Braided or monofilament.
   • Coated or plain.
   • Swaged needle or with no attached needle.
2. List 4 examples of absorbable suture materials.
   • Catgut.
   • Polydioxanone (PDS).
   • Polyglactin 910 (Vicryl).
   • Polyglyconate (Maxon).
   • Polyglycolic acid (Dexon).
3. Of your answers to Q1, which is the odd one out and why?
   Catgut, because it is a natural product; the rest are all manmade. Catgut is also significant since it almost always provokes an allergic response (usually very minor, but can cause irritation, inflammation and seroma formation).
4. Chromic catgut has been treated with chromium salts. Why?
   In order to slow down the rate of breakdown in the body, and therefore improve strength of suture.
5. In addition to catgut, can you name 2 other natural suture materials?
   • Linen.
   • Silk.
6. List 4 examples of non-absorbable suture materials.
   • Polyamide (Ethilon).
   • Polybutylester (Novafil).
   • Polypropylene (Prolene).
   • Silk.
7. List 3 examples of coated suture materials.
   • Chromic catgut.
   • Ethibond.
   • Vicryl.
8. List 3 examples of braided suture materials.
   • Dexon.
   • Stainless steel.
   • Vicryl.
9. List 4 examples of monofilament suture materials.
   • Catgut.
   • Nylomide/Supramid.
   • PDS.
   • Prolene.
10. How are suture materials usually sterilised?
    By gamma irradiation or ethylene oxide.
11. Can you list 4 factors to be taken into account when choosing a suture material?
    • Capillarity.
    • Knot strength/security.
    • Tensile strength.
    • Tissue drag.
    • Cost.
    • Tissue reaction.
12. For what purpose might you use staples, monofilament nylon or polypropylene?
    The closing of the skin (external).
13. For what purpose might you use polydioxanone, polyglactin 910 or polyglycolic acid?
    Suturing of the subcutis.
14. Suggest a material suitable for suturing the bladder.
    Polydioxanone (PDS).
15. Suggest a material suitable for suturing muscle.
    PDS.
16. * Suggest 4 suitable uses for polypropylene (Prolene).
    • Suturing of a hollow viscus.
    • The suturing of tendons.
    • The suturing of blood vessels.
    • The suturing of nerves.
17. How are suture needles classified?
    • By type - eg. round bodied, conventional cutting, reverse cutting.
    • By shape - eg. straight, ¼ circle, 3/8 circle, 5/8 circle, half curved, J needle, compound curve.
18. List 3 factors that determine the strength of a suture needle.
    • Diameter of the wire from which the needle is manufactured.
    • Cross-sectional shape.
    • Type of wire from which the needle is manufactured.
19. Why should bent suture needles be discarded rather than attempts made to straighten them?
    Needles bend when a force is applied which is greater than that for which the needle has been designed. Once this critical point has been reached, the needle is weakened and therefore should not be used.
20. List important factors concerned with the use of needle holders.
    • Carefully select a needle holder to match the size and strength of the needle to be used.
    • Never use a needle holder larger than necessary since this can result in damage to the needle and in particular distortion of the curvature.
    • Never use needle holders with worn jaws since this can result in needle rotation and instability, as well as damage and loss of strength.
    • Never apply excessive force when gripping the needle.
21. * Suggest a suitable type and size of needle for the suturing of an intestinal incision in a rabbit.
    A round bodied needle - size 16.
22. Describe a reverse cutting needle.
    This needle has its cutting edge on the outside of its curvature in order to improve its strength and resistance to bending.
23. What is the most likely cause of the bending of a needle?
    The use of too smaller needle for a given tissue bite.
24. What is the main advantage of a tapercut needle?
    This combines the initial penetration of a cutting needle with the minimised trauma of a round bodied needle.
25. * When might the use of a trocar point needle be indicated?
    When powerful penetration of deep, dense tissue is required.
26. * When might the use of a micropoint needle be indicated?
    Ophthalmic surgery.
27. Why is it that a needle should be as close as possible in diameter to that of the suture?
    Large needle tracts invite bacteria and foreign substances to enter the wound, thus delaying healing.
28. Name the suture pattern most likely to lead to complete wound breakdown.
    Simple continuous.
29. When might the use of simple interrupted sutures be indicated?
    As a buried suture when the suture ends should be cut short.
    For skin closure.
30. When might the use of simple continuous sutures be indicated?
    The closure of subcutaneous tissues.
    For skin closure.
31. What suture patterns are ideal for the closure of skin wounds under moderate tension?
    Horizontal or vertical mattress.
32. What is another name for a swaged needle?
    Atraumatic.
33. After what period are non-absorbable skin sutures usually removed?
    Usually anything from 7-21 days depending upon the type of wound.
34. You are asked to remove the sutures from a bitch 10 days following ovariohysterectomy. The wound appears closed, but is quite red and sore as a result of her licking. What would you recommend?
    • Assess vital signs including hydration status and CRT to rule out internal haemorrhage.
    • Remove alternate sutures in case of wound breakdown and re-examine the bitch in 3-5 days to reassess.
    • Prevent further patient interference by providing an Elizabethan collar.
    • Advise salt-water bathing twice daily to ensure that the wound is kept clean.
35. Give 3 alternatives to sutures.
    • Staples.
    • Tissue glue.
    • Adhesive tapes.