Healing wounds by suturing to accelerate it's healing process.

1. Wound Healing and Suture
Knowledge
ASR Certification Prep
Kim Bayer, SRS, BS, CVT, LATg

2. Tissue Handling / Technique
Goal is to minimize trauma
 Gentle
use minimal tension with tissue
Retractors should be placed to avoid excessive
tension
 Proper use of instruments
DO NOT CRUSH
 Use Proper Technique
 Keep Tissue Moist
Dry tissue is dead tissue
 Minimize Time

3. Incisions
 Heal side-to-side, not end-to-end
– There is little advantage to making an incision too
small to easily view the surgical site

4. Tissue Handling / Technique
Different surgical techniques
induce different levels of
damage
 cutting with sharp instrument
 minimal traumatic
 cuts / divides the cells
 little adjacent cell damage
cutting with scissors
 causes crush and tear trauma
 relatively traumatic
 adjacent cell damage

5. Tissue Handling / Technique
blunt dissection between / along tissue planes
minimal trauma

6. Tissue Handling / Technique
clamping tissue with hemostats / etc.
 causes crushing of the cells
 very traumatic
 causes release of vasoconstrictors, clotting
factors
 proper for clamping vessels for ligation /
hemostasis

7. Tissue Handling / Technique
provide gentle retraction with proper
instruments

8. Tissue Handling / Technique
Keep Tissue Moist
“The solution to pollution is
dilution”
Irrigate, rinse the incision surgery site
Lavage, irrigate body cavities

9. Hemostasis
 Bleeding should be stopped whenever possible
– Excessive bleeding may cause hematomas or increase
dead space
– Hematomas prevent wound apposition and retard healing
– Blood is a natural food for micro-organisms and a large
clot will help protect them from the body’s immune
system
» Bacteria inside the clot will be protected
 Bleeding may be slowed or stopped by applying
pressure, clamping, electro/thermocautery, and with
various chemicals
– Excessive pressure may lead to tissue necrosis

10. Dead Space and a Clean Wound
 Remove all non-essential material
 Wounds with excessive debris should be
thoroughly lavaged with an appropriate sterile fluid
(isotonic saline, LRS, Tis-U-Sol, etc.) to flush them
away
 Dead Space is an open area in closed tissue
– Filled with room air, it prevents tissue apposition,
provides a space for blood and other fluid influx, and
may harbor micro-organisms

11. Dead Space

12. Classification of Wounds
 Clean
– Standard surgical wound
 Clean-contaminated
– Clean wounds that are contaminated by entry into a viscus
resulting in minimal spillage of contents
 Contaminated
– Lacerations, fractures, gross spillage from the GI tract, resulting
from a break in aseptic technique
– Within 6 hours of initial colonization a wound can be infected

13. Classification of Wounds
 Dirty-infected
– Caused by perforated viscera, abscesses, or a prior
clinical infection
– Ongoing infection at time of surgery may lead to a
400% increase in infection rates

14. Problems
 Infection
– The source of infection should always be determined
– Before closure of an infected wound the wound should
be drained, debrided, and a small opening or drain left
in
 Dehiscence
– Wound reopens
– May result from too much tension on tissue, improper
suturing technique, or improper suture materials

15. Wound Healing
 Skin and fascia are
the strongest but
regain tensile strength
quite slowly
 Stomach and small
intestine are weak, but
heal quickly

16. Physiology of Wound Healing
Phases of Wound Healing
Inflammatory Phase
Migration /Proliferation Phase
Maturation Phase
Incision
Inflammatory Migration /Proliferation Maturation
Healed

17. Physiology of
Wound Healing
Inflammatory Phase
0 - 5 Day
 can be prolonged
inflammatory and “clean-up” process
 plasma, cells, fibrin, blood components
 neutrophils, monocytes
• remove debris
• “remove the trash”
epithelialization / migration (as early as 48 hours)
clinically characterized by swelling, redness, warmth
strength due to suture
Incision
Inflammatory

18. Physiology
Inflammatory Response
Clinical Signs
 swelling
 redness
 warmth / heat
Course / Duration
 peak within 24 hours,
 subsiding by day 3
Inflammation results in pain /
discomfort

19. Wound Healing-Phases
 Phase 1
– Inflammatory response
causes an outpouring
of tissue fluids,
accumulation of cells
and fibroblasts, and
increased blood supply
– Leukocytes produce
enzymes to dissolve
and remove damaged
tissue debris

20. Wound Healing-Phases
 Phase 1 (day 1 to 5)
–Inflammatory response phase
–Fluids flow into the wound and a scab forms
–Localized edema, pain, fever, and erythema
present
–Basal cells migrate over the incision from the
skin to cover the wound
–Closure material is the primary source of tensile
strength

21. Wound Healing-Phases
 Phase 2
–Fibroblasts begin
forming collagen
fibers in the wound
»Beginning of the
return of tensile
strength

22. Wound Healing-Phases
 Phase 2 (day 5 to 14)
–Fibroblasts migrate toward the wound site
»Begin forming collagen fibers
–Tensile strength rapidly increases
–Lymphatics recanalize
–Blood vessels bud
–Granulation tissue forms
–Capillaries develop

23. Physiology
Maturation Phase
begins ~ day 14 and continues for months
collagen fibers become oriented along the
“stress” line of the incision and form
crosslinks
• increases tensile strength
contraction
Incision
Maturation
Healed

24. Wound Healing-Phases
 Phase 3
–Sufficient collagen is
now laid down to
withstand normal
stress

25. Wound Healing-Phases
 Phase 3 (day 14 until done)
–Tensile strength continues to improve for as
long as one year
–Skin regains 70 to 90% of its original strength
–Collagen content remains constant but cross-
links with other fibers
–Scar is formed which grows paler as new vessel
construction tapers off
–Wound contraction occurs over a period of
weeks or months

26. Wound Healing Types
 First Intention
– Wound edges brought together during closure at the time of
surgery
 Second Intention
– Wound is left open and heals from the bottom up
– Slower than first intention and creates more granulation and scar
tissue
 Third Intention
– Wound is initially not closed and remains open until a granulation
bed formed, then the granulated tissue is closed using standard
techniques
– Useful in infected wounds
» Infected tissue should not be closed or it will dehiss
» Infection is resolved naturally, or with topical and systemic treatments

27. Closure / Suturing
Proper Apposition
Restore alignment of the
tissues
close / decrease dead
space
balance adequate closure
with too much suture
• suture is a foreign body and too
much can effect healing

28. Closure / Suturing
Proper Suture
use minimal size suture that
has sufficient strength
knot security
absorbable vs. non-absorbable

29. Sutures
 Ideal suture material
 All-purpose, composed of material which could
be used in any surgical procedure (the only
variables being size and tensile strength)
 Sterile
 Nonelectrolytic, noncapillary, nonallergenic, and
noncarcinogenic
 Nonferromagnetic, as is the case with stainless
steel sutures
 Easy to handle

30. Sutures
 Ideal suture material
 Minimally reactive in tissue and not predisposed
to bacterial growth
 Capable of holding securely when knotted
without fraying or cutting
 Resistant to shrinking in tissues
 Absorbed with minimal tissue reaction after
serving its purpose
 Doesn’t exist!

31. Sutures
 Surgeon should select suture materials for
– High uniform tensile strength (quality)
– Permitting use of finer sizes
» Suture should be the smallest diameter that will do the job
– Consistent uniform diameter
– Sterile
– Pliable for ease of handling and knot security
– Freedom from irritating substances or impurities for
optimum tissue acceptance
– Predictable performance

32. Sutures
 Size
–Generally stated in “oughts”; i.e., 3-0, 5-0,
etc.
–2-0 is larger than 4-0, 0 is larger than 2-0, etc.
–Some suture and wire is larger than 0, then
numbered 1 and higher
»2 is larger than 1, 6 is larger than 1, etc.
–From smallest to largest:
»7-0, 3-0, 0, 1, 3, 7, etc.

33. Sutures
Monofilament
Monofilament is a single strand
»Passes through tissue easily, won’t harbor micro-
organisms
»Ties easily
»May be weakened by crushing (clamping in forceps
or needle holders)
»Has more “memory”
 Continues to hold the shape as it lay in the package
»Good for percutaneous sutures
»Knots may slip over time due to the slipperiness of
the suture

34. Sutures
Multifilament
Multifilament is a bundle of strands, like rope
»Affords greater tensile strength, pliability,
flexibility, and knot security
»May harbor micro-organisms and “wick” them
down the suture
 Should not be used for percutaneous sutures

35. Sutures
Absorbable
Absorbable suture holds temporarily but
gradually loses tensile strength and is
eventually mostly or completely absorbed

36. Absorbable Sutures
Surgical Catgut: Plain or Chromic
Absorbed by proleolytic enzymatic digestive process.
Polyglactin 910 : Vicryl®
Polyglycolic acid: Dexon®
Poliglecaprone 25: Monocryl®
Polydixanone: PDSII®
Polyglyconate: Maxon®
Absorbed by Hydrolysis

37. Sutures
Nonabsorbable
Nonabsorbable suture will retain tensile
strength and not be absorbed
»Many nonabsorbable sutures (silk) will lose
some tensile strength over time
»Useful for device fixation, areas of extreme
tension, slow healing areas, or percutaneous
skin sutures
»Selected for procedures where the suture
should be permanent

38. Non-Absorbable Sutures
Monofilament Polypropylene:
Polyester Fiber: Mersilene®,
Dacron®, Ethibond®, Ti.cron®
Monofilament Nylon: Ethilon®,
Dermalon®
Braided Nylon: Nurolon®, Surgilon®
Silk
Surgical Stainless Steel Wire

39. Conventional Cutting Needle
needle body is triangular and has a sharpened
cutting edge on the inside
Primarily used for skin closure.

40. Reverse Cutting Needle
cutting edge on outer curve
For tough, difficult-to-penetrate tissues

41. Taper Point Needle
needle body is round and tapers smoothly to a
point
Used for soft, easily penetrated tissues

42. Blunt Point Needle
Taper body
For blunt dissection and suturing friable tissue

43. Spatula Needle
flat on top and bottom with a cutting edge along the
front to one side
Primarily used for eye surgery

44. Surgeon’s Knot
 Extra throws do not add appreciable strength
to the knot and may, in fact, weaken it while
adding extra bulk
– An initial double throw followed by one or two
single throws is more than sufficient
– The exception is nylon monofilament sutures,
where two successive double throws are useful to
prevent slippage

45. Suture Patterns
 Simple Interrupted
– Maintains strength
and tissue position if
one portion fails
– Requires more time
and suture material
– Has minimal holding
power against stress

46. Suture Patterns
 Horizontal Mattress
– Tension suture
– Useful in skin of dog, cow,
and horse
– Rapid and involves less
suture material
– Difficult to apply without
excessive eversion
– Should pass just below
the dermis

47. Suture Patterns
 Horizontal Mattress
–Tightness should
be such that the
skin edges just
meet

48. Suture Patterns
 Vertical Mattress
–Tension suture
–Stronger than the
horizontal mattress
–Time consuming
and requires more
suture material

49. Suture Patterns
 Cross-mattress
– Tension suture
– Brings tissue into
good apposition
» Useful in suturing
stumps (amputations)
– Also useful for rib
apposition and
abdominal muscle
closure

50. Suture Patterns
 Gambee or Crushing
– Useful in intestinal
anastamoses
» Permits minimal leakage
– May reduce fluid
passage through the
lumen underneath
– Crushing is similar to a
vertical mattress pattern

51. Suture Patterns
 Simple Continuous
– Usually used for lines no
longer than 5”
– Involves one diagonal pass
and one perpendicular
pass
– Provide minimal tension-
holding but hold tissue
together in good apposition
– Creates a good seal
•More prone to failure if
any portion is broken

52. Suture Patterns
 Running
– Both deep and shallow
passes advance
– Regularity more difficult
– Slightly faster than a
simple continuous pattern
– Weaker than a simple
continuous pattern

53. Suture Patterns
 Ford Interlocking
–More stable in the
event of partial failure
or breakage
–Provides greater
tissue stability
–Uses more suture
material

54. Suture Patterns
 Lembert
–Closes hollow
viscera
–Provides inversion
and creates a good
fluid-tight seal

55. Suture Patterns
 Halsted
–Combination mattress
and Lembert pattern

56. Suture Patterns
 Connell
–Begun with a single
inverting vertical
mattress suture
–Continues for the
length of the
incision

57. Suture Patterns
 Cushing
– Modified Connell
where the needle and
suture do not enter the
lumen
– Provides a better fluid-
tight seal than the
Connell pattern

58. Suture Patterns
 Parker-Kerr
– A single layer of
Cushing covered by a
single layer of Lembert
– Used for infected
uterine stumps and
some bowel closures
– Provides complete
clamping to prevent
leakage during suturing

59. Suture Patterns
–Rochester-Carmalt
forceps are used to
clamp the lumen
shut and then
slowly withdrawn
while placed suture
is tightened to
prevent spillage of
contents

60. Suture Patterns
 Guard
– Modified Cushing
– Closes incisions of the
rumen, intestine, and
uterus
– Needle does not enter
the lumen
– Starts slightly higher
than start of incision

61. Suture Patterns
 Continuing
Everting Mattress
–Provides increased
strength
–Rapid placement

62. Suture Patterns
 Subcuticular
– Does not penetrate the
surface of the skin
– Rapid and uses little
suture material
– Used to close the upper-
most layer of the skin
incision
– Requires no suture
removal

63. Suture Patterns
 Subcutaneous
–May use simple
interrupted, simple
continuous, or
horizontal mattress
–Simple continuous is
fast and eliminates
dead space

64. Suture Patterns
 Quilted
–Exteriorized skin
suture through plastic
tubing to resist
excessive tension and
stress
–Useful for high-tension
closures

65. Suture Patterns
 Far-far, Near-near
–Tension pattern
–Overlapping suture
pattern provides
extra strength but
requires extra
suture material

66. Suture Patterns
 Near-far, Far-near
–Tension pattern
–Overlapping suture
pattern provides
extra strength but
requires extra
suture material

67. Suture Patterns
 Mayo Mattress
–Useful for midline
abdominal closures,
abdominal hernia
repair, and
secondary cleft
palate repair

68. Suture Patterns
 Bunnell
–Used for apposing
tendons
»Requires a high degree
of closure strength
–Uses non-absorbable
suture
–Uses a double-armed
suture

69. Suture Patterns
 Modified Bunnell
–Used for apposing
tendons
» Requires a high degree
of closure strength
–Uses non-
absorbable suture
–Uses a single-armed
suture

70. Suture Patterns
 Cerclage Wiring
–Used for fracture repair
–Wire/pin placed in the
bone center to hold it
together
–Wire winds about the
bone under the
periosteum

71. Suture Patterns
 Hemicerclage
–Wire goes through
holes drilled in the
bone

72. Suture Patterns for Specific
Tissues
 Skin- simple interrupted, horizontal mattress,
vertical mattress, continuous apposing or everting
 Subcutaneous tissue- simple continuous
 Fascia- simple continuous (primary), simple
interrupted, vertical mattress, far-near, near-far,
Mayo mattress
 Peritoneum- simple continuous (two-layer), and
simple interrupted
– Very thin and fragile in horse, close muscle instead

73. Suture Patterns
 Vessels- simple interrupted and simple continuous
 Viscera- direct appositional Cushing suture
 Muscle- simple continuous, simple interrupted, and
horizontal mattress
 Tendons- Bunnell
 Bone- hemicerclage and cerclage

74. References
 Clinical Textbook for Veterinary Technicians; McCurnin, D.M.;
W.B. Saunders Co., Philadelphia, 1994
 Ethicon Wound Closure Manual; Available at
http://www.ethiconinc.com/wound_management/procedure/w
ound/
 Fundamental techniques in Veterinary Surgery;
Knecht, C.D.; Allen, A.R.; Williams, D.J.: Johnson, J.H.; W.B.
Saunders Philadelphia, 1981
 Davis + Geck Veterinary Suture Manual, 1991