1. B Y D R C H I N D A J Y
D E P T . O F S U R G E R Y , C H S U N I V E R S I T Y O F
A B U J A
SURGICAL
WOUNDS,CLASSIFICATIONS,
WOUND HEALING AND
COMPLICATIONS
7. Introduction
Wound is the disruption of the normal
architecture/integrity and fxn of a tissue by injury. It
forms the largest surgical burden.
8. Classifications
Based on the degree contamination
(1) Clean wounds-surgical wounds created
under aseptic conditions and there is no breach into hollow
viscus
(!) Clean contaminated-surgical wounds with either minor breach
in the aseptic technique or into hollow viscus with minimal
spillage
-wounds sustained by clean sharp objects and brought in
within the golden hrs.
(3) Contaminated wounds-wounds outside the golden hrs
-surgical wounds with breach into hollow
viscus with major spillage or major breach in the aseptic
technique.
(4) Dirty wounds- surgical wounds with frank pus
Wounds sustained with impregnation of foreign materials in it
9. Classifications
Based on aetiology
-Traumatic
-Infective
-thermal
-chemical
Based on the nature of the wound
Open-laceration,abrasion,avulsion,
penetrating, perforating
Closed-
contusion,concussion,bruise,haematoma,ecchym
10. Wound Healing
This is defined as body’s response to tissue injury.
TYPES:
Although the elements of tissue repair are the same,open and
closed wounds heal differently.
(i) Healing by 1st intension-clean incised wound
apposed by sutures heal ,no
complications.Union by epith.α connective tissue
formation
(ii) Healing by 2nd intension-open healing naturally. Union
is by epith,contraction,α conn. tissue 4mation.
(iii) Healing by 3rd intension- in contaminated wounds,the
wound is dressed until dev. Of granulation tissue b4 is
closed.This is called delayed primary closure,or secondary
closure
11. Elements of wound healing
Three distinct elements contribute to the process of
wound repair:
(i) Epithelization-Process of surface covering
restoration by cell migration(1mm/day) α multiplication.
(ii) Contraction- Edges of an open wound gradually
close together. It is a 4m of tissue migration involving the
skin and the subcut. Its is due to specialized fibroblast in
the wound.
(iii) Conn.tissue 4mation-This is process by which the
main body of the wound is united. The strength of the is
dependent on this and is most the most important of the
three elements.
12. Phases of wound healing
Normal healing occurs by an overlapping sequences of
events involving cellular migration α proliferation,
soluble cytokines and matrix components acting in
concert to repair tissue damage.
The healing response can be described in 4 phases:
(a) Haemostasis. The initial response to tissue damage
is bleeding. Haemostasis is achieved by
–reflex vasoconstriction
-4mation of primary platelet plug
-activation of the clotting cascade leading to fibrin
formation which binds to the plug forming a matrix for
the cellular response.
13. Phases ctd
(b) Inflammation/demolition
Platelet degranulation > release of GFs,chemoattractant
mediators α chemoactivators > chemotaxis of
inflamatory cells to the site of injury α proliferation of
cells locally > vasodilatation α ↑vascular permeability
thro activation of the clotting cascade > influx of cells
and substrates necessary for healing, neutrophil
scavengers,plasma proteins and activated complement
fragments, lately macrophages α monocytes come in to
secrete GFs α cytokines which induce fibroblast
proliferation,angiogenesis α production of extracellular
matrix.
Lag phase,no wound strength
14. Phases ctd
(c) Proliferative
The proliferative phase begins with 4mation of a fibrin,
fibronectin,glycosaminoglycan α hyaluronic acid matrix that is initially
pop. With platelets and macrophages.The macophages secrete GFs which
enhances fibroplasia and migration of fibroblasts into the wound using the
fibrin α fibronectin as scaffold. The fibroblast become the predorminant
cell types by the 3rd-5th day.
The fibroblasts synthesize the extracellular matrix (Ecm).Collagen is the
predorminant Ecm protien,type3 collagen, lately type1 also. Vitc is
necesssary for collagen 4mations.
There is also angiogenesis which allows delivery of nutrients and removal of
byproducts.
The densed population of bld vessels, macrophages,fibroblasts with loose
conn. tissue- granulation tissue
Wound contraction occurs through out this phase.Epith. also occurs within
hrs of injury.
15. Phases ctd
(d) Remodelling/maturation
There is a balance b/w synthesis, deposition α
degradation. The tensile strength of the wound
↑steadily as organized fibrils with more cross-
linkages are laid.
The tensile strength at best reaches 80% of the
preinjury state.
The healing ends up with a scar
