00:01
Now if you...
00:03
if you understood the important
basis of fluid resuscitation,
the depth,
this is what is going to be asked,
there is no absolutely nothing else
they can test you.
00:19
No, I think no,
that's the sort of moral in mainstream.
00:23
That would be under
the wound healing,
wound healing is a
syllabus in your exam,
and that can be around
three to four questions.
00:31
So there may be
questions wound healing,
they'd be one on skin graft,
then one later,
is it plasty or the types of flaps?
I haven't got slides
on that though.
00:42
There are be reason I thought,
I thought you guys will know it.
00:49
It's not a big topic,
but you need to know is,
are you all sure
about those areas?
Not really,
not really, anyone, not really.
01:00
You're okay with the
different things?
I can spend about 10 minutes to go
through the importance through slides.
01:05
Otherwise?
Okay.
01:13
I'll do the local anesthetic
as a presentation,
then we'll go through
the other bit.
01:19
Or maybe to take a break,
we'll do something else.
01:25
Okay, so the questions,
I'll just discuss the questions.
01:33
You know the Oxford University first
used to have a passage syllabus.
01:37
Remember that?
Have anybody use that?
They had to a mass
is part A resource.
01:42
Is called pass it down OUP.
01:44
Nobody's used it.
01:45
No, no, that has been shut down.
01:48
Anyway, I used to moderate
questions for that.
01:50
So I know pretty much
what has been asked.
01:53
So I'll just cover
wound healing,
what comes up?
Types of wound healing
and the phases of wound healing.
02:01
Okay.
02:01
So the four phases
of wound healing.
02:04
So let's say you have a
arm leg trauma laceration.
02:12
What happens immediately?
Hemostasis, what are the
components of hemostasis?
What's the first
thing that happens?
Before that?
What's the first thing?
Endothelial Injury.
02:26
The first thing that happens is
sympathetic response
based on constriction.
02:31
Yeah.
02:31
The first thing is
basic constriction,
followed by platelet
aggregation.
02:36
You have platelet aggregation.
02:38
Then you have the intrinsic and
extrinsic coagulation pathways.
02:42
So, three things happen,
basic constriction, platelet aggregation,
and coagulation
pathways activated.
02:49
So, this is why when the
patient is on aspirin,
platelets are affected.
02:54
Okay, the next thing.
02:56
What's after hemostasis?
Inflammation.
03:01
Okay, questions in your exam.
03:04
What are the cell types
you see in inflammation?
What's the first one?
Neutrophils.
03:10
First is neutrophils.
03:12
In the first 24 hours,
24 to 72 hours,
you get lymphocytes and macrophages.
03:18
Another question.
03:19
Where'd you get
macrophages from?
What are macrophages?
You're right.
03:24
So, they are normally
present in the blood.
03:28
The undergo a
phenotypic transcription
when they come to an
injured site to become...
03:34
to convert, to change from
monocytes to macrophages.
03:38
What's the next stage
in wound healing?
So hemostasis,
inflammation, third one?
What's a space called?
Proliferation.
03:48
Okay, so hemostatic phase
inflammatory phase,
proliferative phase.
03:54
What happens during
proliferative phase?
So during the
proliferative phase were...
04:01
you can even imagine,
you have a wound that
bleeding has stopped
the neutrophils have come in.
04:09
It is cleaning up the wound,
macrophages are coming
to clean up the wound.
04:12
So, they're essentially
laid the groundwork for
new blood vessel formation,
new fibroblasts coming in,
new extracellular
matrix, new collagen.
04:22
So this is all part
of proliferation.
04:24
So the five components
of proliferation are
angiogenesis,
fibroblast proliferation and migration,
extracellular matrix deposition
along with collagen deposition.
04:39
Sorry, okay.
04:41
Proliferation...
04:45
angiogenesis,
fibroblasts proliferation
and migration.
04:51
Before that you get the extra
cellular matrix coming in
which acts as a scaffold,
and the fibroblasts
are lying in that.
05:00
Okay?
This essentially forms
a granulation tissue.
05:05
The last phase of this is
your epithelialization.
05:08
The epithelium from the epidermal
cells coming in, closing the wound.
05:13
So, this is your third
stage of the wound healing.
05:16
And the final stage
is remodeling.
05:19
So, now you have got
a granulation tissue.
05:22
Now, the wound has to shrink,
shrink, shrink, shrink, shrink
and became a scar.
05:27
So, if it all goes smoothly,
you end up with a
nice linear scar.
05:32
But if you have any imbalance
between proliferation,
and degradation of the collagen
you will end up with a
hypertrophic scar or a keloid scar
or a non-healing wound.
05:45
Okay.
05:45
Another question they
will ask you is MMP?
What is MMP stand for?
Matrix metalloproteinases.
05:55
So, the matrix
metalloproteinases,
and the the opposite of this
tissue inhabitants
of metalloproteases,
these two enzymes,
pretty much breaks down all the collagen.
06:10
So, the collagen is forming.
06:12
If the collagen continues to
form without any inhibition,
it will become overgrown scar.
06:19
That's the keloid
or hypertrophic.
06:20
So, these are secreted into
the wound to balance it out.
06:24
And the final phase
is remodeling phase,
where all this
thing is happening.
06:31
So how long does a
remodeling phase last?
It starts from approximately...
06:36
When, when does the
remodeling phase start?
Approximately,
two weeks to around six weeks,
but it can go all
the way up to year.
06:44
So, even after 1 year,
the scar has achieved
only about 80% of its
normal tensile strength.
06:51
A scar will never achieve a
hundred percent of the strength.
06:55
Even after one year,
it's only about 80% strong.
06:59
Okay?
So, that is all part of
the remodeling phase.
07:02
So, the remodeling in the
scar maturation is one phase.
07:06
So, hemostasis, inflammation,
proliferation and remodeling.
07:12
These are four phases
of wound healing,
and they'll ask you what cell
type is involved in each.
07:19
Okay, then the types
of wound healing.
07:21
So if you have a linear scar,
what do you do?
You approximate with the wound,
either with sutures,
staples, glue, etc.
07:31
And that is healing
by primary intention.
07:34
But imagine if that is a
dog bite or a human bite,
you leave it maybe for 24 hours, 48 hours
and close it by delayed primary intention.
07:45
Now, there is a question
or it's been asked before,
in the UK, so many of you will know in
specialized orthopedic or plastics units.
07:53
We are more than happy
to excise it primarily,
and close it even
if it is a dog bite.
08:00
So, it used to be the
norm that a dog bite,
you never close it in
the first 24 hours.
08:05
But imagine a child, two-year-old,
with a bite in the face, small bite.
08:10
You don't want to take the child back
to theater after 48 hours for a GA.
08:15
So, the safest thing to do
is you excise the wound,
clean it up and
close it primarily.
08:22
So, you're converting it that
in do a primary intention wound.
08:29
You do it in adult as well,
you can do it on adult as well,
but the classical example is in a
child, what you do?
Yeah.
08:36
So, traditionally,
you leave to heal,
leave it for 24-48
hours and then close it.
08:43
So, that is healing by
delayed primary intention.
08:46
Okay, the second other type
healing by secondary intention.
08:50
When do we do that?
Infected wounds, okay,
give me some clinical scenarios.
08:57
Abscess.
08:58
Abscess, very good.
09:00
Ulcers also pressure ulcers.
09:03
A laparostomy wounds,
which you really can't close it.
09:07
The only option you have is to
put dressing on, put some back on,
and help it to granulates
and close it from the edges.
09:16
Now, the cell type which is involved in
that type of feeling is myofibroblasts,
not the fibroblasts.
09:22
The myofibroblasts is
a type of fibroblasts
which helps in
wound contracture.
09:27
Those wounds, the scarring is bad
because it heals by contraction
not by the normal
healing process.
09:34
Okay,
what's other type of healing?
So, we discuss true healing
by primary intention,
delayed primary, healing by
secondary and healing by one more.
09:47
Yeah, go on, before that.
09:49
Let's say, if somebody if
you sustain an aberration,
like this just scrape,
how does it heal?
Does it go through all
the wound healing status?
There doesn't scar.
10:01
Okay, another example,
split skin graft,
that heals without a scar.
10:06
How does that happen?
Yes, healing by
re-epithelialization.
10:15
So, that is another phase
of type of wound healing,
where it is not going
through any of these stages
because all the adnexal
structures are still intact.
10:24
All you have done is shaving off
the superficial
breath epidermis,
maybe a little
bit of the dermis,
but all your sweat
glands, hair follicles,
the rest of the dermis is all intact,
so they just re-epithelialized.
10:38
So, that's why they
heal without a scar.
10:42
So, that is the fourth of
the type of wound healing.
10:45
Okay?
Healing by re-epithelialization.
10:47
The classically
seen in operation,
split skin donor graft site.
10:55
Okay.
10:56
So, that's that and what about
the other questions you are asking
is related to do the
reconstructive ladder.
11:03
So, you have...
11:11
let's say somebody
had an abscess,
in the chest and it ends
up with this sort of wound.
11:21
Okay?
You have is just a healthy
normal fit and healthy patient.
11:28
What are your options
to close this?
Primary closure.
11:32
Okay,
so that's your simplest form
of healing by primary
intention or primary closure.
11:41
Okay, I'm still telling you I
can't do it because it's too wide
what's your next option?
Delayed primary closure fine,
but again delayed primary closure has
contracted it, but still not good enough.
11:54
I still can't close
it, it's still big.
11:57
One minute,
just one minute before that.
12:00
Before that, you can try the
secondary intention is the lowest form
because you can put a back on
it and go for this closure,
but that is not ideal.
12:09
This will end up
with a bad scar.
12:11
Okay, so healing by secondary
intention is probably
the lowest form of closure
is more of a primitive,
form if you look at in an
evolutionary perspective.
12:20
If you are got bitten by a
tiger for million years ago,
you didn't have any
of these options.
12:26
You left it to heal by
secondary intention,
so that is a most
primitive form.
12:31
Slightly advanced
is primary closure,
then you said delayed primary.
12:40
Before that, before the
flap, correct, skin graft.
12:43
Okay, now...
12:46
how do you decide, she mentions
local flap, you mentioned skin graft.
12:51
When do you decide skin
graft to local flap or graft?
Well,
it seems on the chest here.
13:07
You can put the split
skin on the dermis.
13:09
What are they contraindications
for a split skin graft?
Bare tendon,
bare tendon, barebone.
13:17
So, if you if you don't
have the periosteum
or if you don't
have the paratenon,
then you can't put a skin graft.
13:23
However, if you have a exposed
tendon or an exposed bone,
but the periosteum is intact.
13:29
You can put a skin graft.
13:31
Okay.
13:31
So, this is your absolute...
13:34
So, for example here,
let's take the same wound on the chest,
is on the pectoralis major muscle, your
first option will be to primary close it,
delayed primary,
then, the next thing you are
considering is split skin graft.
13:49
So, you mentioned skin graft that
is split into full thickness,
and split skin graft.
13:55
Split is the the first
option you consider because
you're not leaving
a donor site wound.
14:03
So because it heals by
re-epithelialization.
14:05
You shave a piece of skin
from here place it on this,
that's a good option.
14:12
Now, if this,
you can't participate skin graft
because let's say this
wound is on the hand,
where the tendon is exposed
there is no paratenon,
the periosteum is stripped off,
then you can't put
a split skin graft.
14:28
Then you have to go
for a full thickness.
14:31
Okay, even then it's risky.
14:35
It might not take,
anything to do with a graft
is dependent on
recipient blood supply.
14:43
Okay?
So, you probably don't want to take
any of this option, if you think,
the recipient blood
supply is compromised.
14:51
What other example I gave you
two, paratenon.
14:54
No periosteum, no paratenon.
14:57
Where else would you not
use a skin graft clinically?
Radiotherapy, treated areas.
15:02
Because if you have an area
treated with radiotherapy,
there is no blood vessel in that area
that is all dead, that's all killed off.
15:09
So, you can't put a skin graft.
15:11
Okay?
What's the difference between a split
and a full thickness skin graft?
Split thickness skin
graft takes only,
will not dermis.
15:20
This epidermis and different
level of the dermis.
15:23
It could have a thick
skin graft or a thin one,
so depends on the level.
15:30
But the most important thing is,
the donor site is left to
heal by re-epithelialization.
15:37
Full thickness skin graft,
you take the whole of the dermis
and the donor site
is closed primarily.
15:44
So, the common sides for full
thickness graft donor sites
are preauricular, post
auricular, supraclavicular,
and the inner aspect of the
arm and as well as the groin.
15:56
These are the common size for
a donor sets of full thickness.
16:00
For a split, it is usually that last
bit of thigh buttock and the back.
16:04
Okay,
So, we come to the situation
where you can't use any of this.
16:09
That's when you go
for a local flap.
16:14
So, you have a whole.
16:17
You can't put a graph
here, you can't close it.
16:19
Then, the only option
is to do a local flap.
16:22
So for example, what you can do is you
can make this into a rhombus shape,
and then you put a local flap.
16:29
This is a rhomboid flap.
16:32
Okay, so this goes into that.
16:35
So here, the blood supply is taken from
there and rotated and pushed in here.
16:41
Okay, so that's your local flap.
16:44
Now, let's say the
wound is very big.
16:47
You can't put a local flap.
16:49
What's next option?
Pedicle flap.
16:51
So that's your classic
example is mastectomy.
16:54
Okay?
So,
a mastectomy say for stage 3,
no, you didn't have to
actually know clearance,
then use latissimus dorsi muscle
as a pedicle flap to cover it.
17:08
So that is a classical
pedicle flap.
17:18
Okay.
17:21
We'll stay on the same example.
17:23
Mastectomy, patient is not suitable
for a particular flap because of
maybe because of radiotherapy,
axillary node clearance,
or the latissimus dorsi
muscle is not big enough,
whatever reason or the
vessel is not big enough.
17:37
Then you go for the free flap.
17:44
So, this is your reconciling
ladder, going from the simplest one
to the most complex.
17:50
So, the free flap for a breast,
you could take from the abdomen
like the in deep inferior
epigastric perforator,
superior gluteal artery perforator
flaps or any of the perforator flaps,
or any of the free flaps,
but the concept is you are
detaching blood vessel.
18:07
And reattaching it.
18:09
In these two,
you're not detaching the blood vessel.
18:13
You are just moving
the blood vessel.
18:16
Okay, and in these two,
you are dependent on the
recipient blood vessel.
18:36
So in the in terms of flaps,
you can be asked two flaps,
you should ask about
rhomboid flaps.
18:41
Rhomboid flap is a
type of local flap.
18:44
It is the rhomboid,
the angle you need to remember is,
this angle is 120 degrees
and this is 60 degrees.
18:53
You know, that's the only number
you need to remember 120 and 60,
and shape of rhomboid and you
make a flap and push it in.
19:01
Okay, so that's a rhomboid flap.
19:04
The other one they ask
is, 'is that plasty?'
Have come across,
'is that plasty?'
When do you do if it's plasty?
And what is it?
It's okay, done it.
19:22
You can do pretty much at anywhere
but usually, you have a long scar.
19:27
Imagine this is a
very, very tight scar,
and say it's on the axilla here.
19:32
The only way to release a scar is to
reorient the direction of the scar.
19:37
Okay, so you turn the direction
of the scar to slightly different.
19:40
So, that you get much more
external rotation or friction.
19:44
So, plasty is a technique
whereby that's exit.
19:49
Okay, this is the exit.
19:53
So, you make a incision here,
you make an incision there,
and then you move
these flaps around,
you move that flap,
one flap to here.
20:02
So are essentially reorienting
the direction of the scar
and you are leasing
the contraction.
20:07
So, that's the principle.
20:11
Now depending on how
you make the angle,
you get more or less release.
20:17
So, you can make a very obtuse
is it or on very acute is it.
20:25
Clearly with this you can
more recruitment of tissue
because you are taking more
tissue and bringing it in.
20:30
So, the answer to
your MCQs will be,
it is to reorient the scar as well
as to release the contraction.
20:38
Okay.
20:38
So, this is not a type of
flap but it is a type of flap,
but it is that plasty
is a technique.
20:49
They may ask you.
20:52
Okay, anything you want to ask?
I think that's all
about wound healing.
20:59
Any question on those
that have you been asked,
have you seen any
other question in this.
21:03
You have?
On what?
On flap,
sorry anything apart from this?
No.
21:11
Okay.
21:11
Two things I need to cover
because it always comes
a bonus biopsy and the
second was local anesthetic.