Chapter 25 - Principles fo Plastic Reconstructive Surgery Flashcards
What is the primary goal of plastic and reconstructive surgery as described in the text?
Achieving wound closure and restoring function.
Why is understanding the general process of wound healing critical in equine surgery?
It forms the basis for developing an effective treatment plan.
What factors must be considered when deciding on wound management?
Type of injury, location, degree of contamination, age of the wound, integrity of blood supply, and skin loss.
What is a significant challenge in managing soft tissue injuries in horses compared to humans?
The physical size of equine patients and their environment.
What are the different methods of wound closure mentioned in the text?
Primary closure,
delayed primary closure,
secondary closure,
healing by second intention.
When should immediate wound closure be considered?
For clean or clean-contaminated wounds with adequate blood supply.
What mistake do equine practitioners often make in early wound management?
Premature closure of heavily traumatized or contaminated wounds.
How long should wounds be managed before considering closure for better outcomes?
1 to 3 days.
What is associated with delayed closure after the appearance of granulation tissue?
Reduced wound sepsis.
What is often the best treatment option for wounds with significant skin deficits?
Secondary closure or open wound management.
What complications may arise from second-intention healing?
Exuberant granulation tissue and delays in contraction and epithelialization.
How can reconstructive and skin-mobilizing techniques help in wound management?
They minimize cosmetic and functional shortcomings.
What are some clinical situations where reconstructive procedures are utilized besides traumatic wounds?
Planned excision of skin lesions.
What are the benefits of using reconstructive procedures in wound management?
Improved cosmetic appearance, function, and reduced healing time.
What types of vessels supply the skin in mammals?
Perforating musculocutaneous vessels
and direct cutaneous vessels.
How is horse skin primarily supplied?
By direct cutaneous arteries.
What is the role of the superficial plexus mentioned in the text?
It is part of the thermoregulatory system and maintains blood supply integrity.
What are skin flaps and what role do they play in equine surgery?
Skin flaps are tissue sections used in reconstructive surgery to cover defects and improve healing.
How do viscoelastic properties of skin influence surgical outcomes?
They affect how skin responds to tension and stress, influencing incision healing.
What are the three structural components of skin that provide its properties?
Collagen, elastic fibers, and ground substance (primarily proteoglycans).
Define static tension in the context of skin properties.
Tension that results from the skin clinging to the underlying body.
How do dynamic tension and static tension differ?
Dynamic tension is caused by underlying muscle pull, resulting in visible skin wrinkles.
What are Langer lines, and why are they significant in surgery?
Lines of maximal tension that guide incision placement to improve healing and minimize scarring.
How does skin anisotropy influence surgical incisions?
It affects how skin tension reacts to movement and surgical cuts.
What effect does incision angle have on wound healing?
Incisions parallel to tension lines gap less, heal better, and result in finer scars than those made at right angles.
What does the text suggest about the relationship between wound edges and tension during débridement?
Avoid smoothing irregular edges to prevent increased tension during closure.
What happens to incisions made at right angles to lines of tension?
They gape widely and require more sutures, resulting in unsightly scars.
What is the benefit of delaying closure of a wound until granulation tissue appears?
It can reduce complications and promote better healing.
How many plexus exist in the dermis?
3 plexus:
deep subcutaneous plexus
the middle cutaneous plexus
superficial subpapillary plexus
What are the skin flaps developed based on the major cutanoeus arteries of the trunk?
Vascularized free flaps
island arterial flaps
Axial pattern flaps
A skin flap based on the cutaneous portion of the caudal branch of the _____ _____ _______ artery has been described in experimental studies of a vascularized free tissue transfer
deep circumflex iliac artery
What are teh 3 structural components that impart tension and viscoelascticity?
groudn substance
collagen
elastic fibers
What are viscoelastic materials?
viscoelastic materials are those for which the relationship between stress and strain depends on time.
If the stress is held constant, the strain increases with time this is _________ (1w)
creep
if strain is held constant, the stress decreases with time this is _______ (1w)
relaxation
Tension is
the magnitude of force skin can exert
There are 2 types of skin tension name them
static tension (skin clinging to the underlying body
dynamic tension which results from the pull of the underlying muscles and is seen as wrinkkles in the skin
What does it mean: skin is anisotropic
lacking similar properties in all directions
skin tension lines are influenced by
muscle contraction, movement of joints, and other external forces
Langer lines are more accurately referred to as
relaxed skin tension lines
When excising an elliptical piece of skin, closure is facilitated by ensuring that the long axis of the ellipse is aligned to________________ (2w)
Langer lines
Mechanical creep is a biomechanical property of skin - give definition
which allows it to stretch beyond its normal limits of extensibility under a constant load.
Biological creep differs from mechanical creep in that the skin does not stretch, but instead increases area of coverage by increasing 3 things name them
epidermal mitotic activity,
upregulation of blood vessels,
and increasing dermal cell numbers, resulting in skin development (pregnancy, body wall hernias)
When cosmetic appearance is important, sutures should be removed by ____ to ___days, regardless of suture type.
When cosmetic appearance is important, sutures should be removed by 10 to 14 days, regardless of suture type.
Apposition is best obtained by maintaining the needle ___________/(1w) to the skin during skin penetration
Apposition is best obtained by maintaining the needle perpendicular to the skin during skin penetration
Tissue strength or suture size or number of suture bites is a more important determinant as to whether or not a wound will dehisce?
Tissue strength and not suture size or number of suture bites is a more important determinant as to whether or not a wound will dehisce
More sutures are required in thinner skin or in thicker skin?
More sutures are required in thinner skin than in thicker skin
define intrinsic tension
define extrinsic tension
Tension on sutures can lead to 3 things (negative) name them
- Necrosis (lack of blood supply
- increasing edema
- Decreasing tissue perfusion
Subcutilar and intradermal suture objective is
minimize dead space
Simple interrupeted sutures have been shown to have 3 good characteristics
Excellent tissue apposition
compromiss less microvasculature
greater tensile strenght
Simple continuous in case of knot failure a breakdown happens but also other disadvantages name them (3)
increment EDEMA + COMPROMISED CIRCULATION + PROLONGING EFFECT OF INFLAMMATORY PHASE OF WOUND HEALING
Corner suture is also called
3 point or half buried mattress suture
In the corner suture it starts as routine horizontal matteress but instead of penetrating the full thickness, only a ________ __________ _____(3w)
only a partial thickness bite
Simple interrupted
interrupted intradermal/subcuticular
Figure 25-2. Corner suture used to minimize vascular compromise to the tip of the flap.
Figure 25-3. A stent bandage consists of rolled up sterile gauze sponges sutured with a large, simple continuous suture pattern over an incision closed with simple interrupted sutures.
A barbed suture equipped with a loop at one end for fixation of the first suture loop and unidirectional barbs throughout the length of the suture strand can be used for tissue apposition. These barbed suture materials allow knotless suturing
cushing
Gambee; this pattern can be used as an appositional suture pattern for skin (a) or
Gambee; this pattern can be used as an appositional suture pattern for intestine
Tension along suture lines can result from attempting to close wounds where there has been loss of
skin
swelling in the area
loss of elasticity
Tension sutures can be used either alone or in combination with appositional patterns such as
simple interrupted sutures
other skin-mobilization techniques such as undermining
release incisions
What are the 2 types of mattress sutures?
Horizontal or vertical depending on their orientation to the skin
Horizontal and vertigal suttress have tendency to invert or evert sking edges?
evert
How far away should be placed the mattress sutures?
2 to 4 cm away from the wound margin
Which pattern is stronger under tension, vertical or horizontal?
vertical as with simple interrupted suture and results in little if any compromise to the microcirculation
Horizontal mattress sutures may result in ischemia within
the suture loop and for this buttons, plastic or rubber tubing or gauze can distribute pressure
Sutures with buttons, plastic or rubber are known as
qulled support
quilled
stented sutures
Allgower corium vertical mattress
Interrupted vertical mattress
far-near-near-far suture pattern combines a tension suture, the far portion, and an
appositional suture, the near portion
Advantage and disadvantage of far-near-near-far
advantage: higher tensile strength than either a simple interrupted or a mattress pattern
disadvantage of requiring that a large amount of suture material be placed in the wound
(E) walking suture - Walking sutures have been described for closing skin defects in small animals, particularly in areas where the skin fits loosely, such as the trunk
Biomechanically, the addition of negative-pressure wound therapy decreases lateral tension forces on sutured incisions by approximately ___%
Biomechanically, the addition of negative-pressure wound therapy decreases lateral tension forces on sutured incisions by approximately 50%
Bandage should be changed every ___ to___ days
3 to 5 days
Despite skin healing, tissue strength is only ___% of normal tissue at 3 weeks,
___% at 3 months, and can remain 20% to 30% weaker than the original tissue at 1 year
Despite skin healing, tissue strength is only 20% of normal tissue at 3 weeks, 50% at 3 months, and can remain 20% to 30% weaker than the original tissue at 1 year
Tension on suture lines can result in several symptoms (name 4)
discomfort for the animal, increased scarring, ischemia of the skin margin, and suture line breakdown with partial or complete wound dehiscence.
consequences of tension across suture lines can be attenuated by 3 tx name them
using tension sutures
undermining the surrounding skin
by using tension-relieving incisions or skin-mobilization techniques
Undermining skin edges around the wound or excision site prior the closure is the simplest tension-relieving procedure You can accomplish with 2 types of dissecation name them
blunt or sharp dissection (careful to the blood and nerve supply
When sharp dissection is used, there is an increase in bleeding, which may lead to hematoma formation. What can you place prior skin closure to avoid issues?
Placement of a drain prior to skin closure or a pressure bandage after clorsure
Skin on the trunk should be elevated below the level of the __________ _________ (2w)
panniculus muscle to preserve the small direct cutaneous vessels
In fresh wound how much should be elevated on each side of the wound?
A distance equal to the width of the defect itself should be elevated on each side of the wound
What consists tissue debulking?
removal of exuberant granulation tissue or fibrous tissue reduces the volume of the tissue in the wound, which allows closure under less tension
Tension-release incisions what are they
longitudinal incisions made adjacent to the wound margin, which aid in advancing skin to cover the wound
can be made on either side of the wound or on both sides.
How far should be the release incision?
When making a single release incision the incision should be placed at a distance of approximately the width of the wound away from the wound’s edge over healthy tissue
Mesh expansion is simple tx that when combined with undermining can
increase the amount of skin available for mobilization and therefore wound coverage
Mesh expansion in fresh wounds, the distance between the individual stab incisions and between the adjacent rows should measure approximately __ cm
the adjacent rows should measure approximately 1 cm
The small incisions are made in staggered rows, parallel to the wound edge
In fresh wounds, more expansion can be obtained with _______(smaller/longer) incisions, whereas for those wounds where the surrounding skin is thickened and fibrotic, ________(smaller/longer) incisions are required to achieve the same result
fresh wounds, more expansion can be obtained with smaller incisions, whereas for those wounds where the surrounding skin is thickened and fibrotic, longer incisions are required to achieve the same result
Figure 25-6. V-to-Y-plasty for tension relief. With this technique, tissue is mobilized in the direction of the arrow.
3 reasons to use Z plasty
To relieve tension along a linear scar
change orientation of an incision line or a scar
to relieve tension when closing a large defect
Z plasty is suitable in distal limb?
No because this procedure depends on the presence of sufficient loose skin int he area to permit mobilization of tissue
Z plasty represents a modification of a
transposition flap
How is performed the Z plasty?
The basic Z-plasty is performed by making a Z-shaped incision with subsequent undermining and transposition of the two triangular portions of skin formed by the dissection
What angle is used in Z plasty?
angle of 60 degrees is most frequently used, which results in a 75% gain in length
The Z in Z plasty is made symmetric with 3 limbs equal?
yes, the Z is symmetric with the 3 limbs of equal length and the same angle between the 2 arms and the central limb
Maintaining a 60-degree angle and lengthening the limbs of the Z can achieve an increased gain in
length - however, the greater the increase in length, the greater will be the resultant tension in the surrounding tissue.
Z plasties are used in horses to close two types of defects name them
have been recommended as a relaxation procedure for:
- closing elliptical defects
- and for revising scars involving the eyelids that have resulted in an acquired entropion
The most common complication encountered with the use of a Z-plasty is
ischemia and necrosis
Figure 57-12. V-to-Y plasty for ectropion. (A) The area of ectropion is identified. (B) The V-incision is made with a scalpel. (C) The skin flap is elevated, and underlying cicatricial tissue is excised using scissors. (D) The skin flap is advanced to relieve skin tension. Closure is performed in a Y pattern
W-plasties are designed to
improve the cosmetic appearance of a scar.
Skin-Stretching and Expansion Techniques
Presuturing is based on what?
is based on the phenomenon that skin held in tension will gradually stretch. It is an ideal method to consider when elective procedures, such as skin biopsy, scar revision, or delayed wound closure
What sutures are used?
Large, nonabsorbable sutures (No. 1 or No. 2, polypropylene or nylon) are placed through the skin perpendicular and 2 to 6 cm to either side of the lesion
Sutures in presuturing should be removed how tme after to avoid edema?
2.5 hours
Intraoperative tissue expansion can be obtained how?
obtained by techniques:
- as simple as the placement of towel clamps and pulling the wound edges together for a short period of time prior to closure
- or the insertion of a Foley catheter in which the balloon is then inflated
For how long the tension in intraoperative tissue expansion should be applied?
tension being applied in three or four cycles of 3 to 5 minutes to a single cycle for 20 minutes
External Skin-Stretching Devices can be used with inexpensive suplies such as skin staples or
spinal needles
In External Skin-Stretching Devices the staples are placed at what distance from the open wound
0.5 cm adjacent and parallel to the open wound.
greatest gains in skin recruitment are seen between ___ and ___ hours
48 and 72 hours
The applied tension between the sides of whatever system is used should range between ___ and ___ kg
The applied tension between the sides of whatever system is used should range between 0.5 and 4 kgs. Tensions greater than this can injure small blood vessels, decreasing perfusion and leading to skin margin necrosis
Tissue expanders are made of
silicone elastomer, are balloons of varying dimensions, which, after being implanted subcutaneously, can be distended percutaneously over time with saline
What size is the elastomer?
An elastomer with a base size 2.5 times that of the defect that is to be reconstructed is selected and implanted below the skin adjacent to the lesion site
After the implant incision has healed the pouch is expanded every____ to ___ days
implant incision has healed, the pouch is expanded every 4 to 7 days through a dedicated self-sealing portal, thereby stretching the overlying skin
Tissue expanders uses two types of creep, name them
mechanical and biological creep
Complications of tissue expanders
Complications include possible
pain during saline distention,
pressure necrosis of overlying skin,
implant failure,
wound dehiscence,
and premature exposure of the expander necessitating its removal before adequate expansion had been achieved
Fusiform excisions can be used for elective scar revision, with the long axis of the defect being oriented ________(1w) to the lines of skin tension
Fusiform excisions can be used for elective scar revision, with the long axis of the defect being oriented parallel to the lines of skin tension
In fusiform excision ___ : 1 or ___ : 1 length-to-width ratio will allow closure of the defect with a fairly even distribution of tension along the length of the suture line
3 : 1 or 4 : 1 length-to-width ratio will allow closure of the defect with a fairly even distribution of tension along the length of the suture line
Figure 25-4. Fusiform excision. After excision, the skin is undermined to facilitate closure of the defect. The optimal length-to-width ratio of the fusiform defect is 4 : 1.
In case of triangular, square and rectangular defects they should be closed from _______________ towards which will result in the formation of Y-shaped suture line
In case of triangular, square and rectangular defects they should be closed from the points of the triangle towards the center which will result in the formation of Y-shaped suture line
Closure of circular defects commonly results in the formation of
dog ears
A circle can be converted into either an ____ or Y shape by tightening sutures placed at three or four points equidistant to each other around the circumference of the defect.
A circle can be converted into either an X or Y shape by tightening sutures placed at three or four points equidistant to each other around the circumference of the defect.
What is the simplest way to close a circular defect?
The simplest method of facilitating closure of a circular defect is to excise two triangles on opposite sides of the circle, thereby creating a fusiform defect
While doing a fusiform defect while closing a circular defect the height of each triangle should be at least (equal/bigger/smaller) to the diameter of the circle
Figure 25-8. Methods for removal of dog-ears. (A) The dog-ear is held securely, elevated and is excised level with the surrounding skin, leaving a small fusiform defect to close. (B) The dog-ear is bisected to form two small triangular flaps, which are resected level with the skin surface.
What is a skin flap?
A skin flap or pedicle graft is a portion (or flap) of skin that, when created, can be moved from its original location to a second location on the body while, by virtue of its attachment (or pedicle), it maintains its vascular supply
Flaps can be classified as (2 w)
LOCAL OR DISTANT BUT DISTANT FLAPS ARE NOT USED IN HORSES
Local flaps include 3 types
rotation
transposition
interpolating
Skin flaps can be classiedied acording to the nature of their vascular supply
Random pattern flaps do not have a defined vascular pattern, depend on the subdermal plexus
Axial pattern flaps contain at leasst one major direct afferent and efferent cutaneous vessel
correlation of flap width to viable length in random pattern pedicle flaps of the trunk has been shown - TRUE or FALSE
TRUE - The narrower the pedicle of the flap, the more maneuverable it will be, but the greater will be the chances of compromising its blood supply. On the other hand, a wide-based flap will have a good vascularity, but mobility, particularly rotational, is limited
Flaps raised on the trunk should be elevated beneath the (2 w)
cutaneous musculature
Flaps raised on the limb, dissection should be performed deep in the (2w)
subcutaneous tissue
Sharp corners in the flap should be avoided, why?
Prone to ischemia
Figure 25-9. Simple bipedicle flap. This can be used with a single incision, as depicted here, or a second incision can be made on the opposite side of the primary defect. By using two relaxing incisions, it may be possible to close the secondary defects.
Figure 25-11. Rotation flap. This pedicle flap is semicircular and can be used to cover small defects.
Advancement flaps are random pattern flaps that have 2 classifications, name them
single
or bipedicle type
Advancement flaps are also named
sliding flaps
A V-Y-plasty is an example of an advancement flap?
Yes
Simple bipedicle advancement flaps are performed with 2 types of incision, name them-
- making a single longitudinal incision on one side of the wound
- or by incising on each side of the defect
The bipedicle nature of this flap (Figure 25-9) provides ____(number) sources of blood supply to ensure survival of the mobilized portion of skin
2 sources of blood supply
An H-plasty is a modification of a _____ flap
An H-plasty is a modification of a single-pedicle flap
An H-plasty is used to closure of a __________ (1w) defect
rectangular defect
Figure 25-10. Sliding H-plasty. Burow triangles are created and excised to prevent dog-ear formation after mobilization of the skin.
How is performed an slidding H plasty?
Two single-pedicle flaps are used on opposite sides of the defect to advance the skin, and Burow triangles are excised at the base of both pedicles to avoid dog-ear formation
How many rotating flaps exist?
3 types:
1) rotation
2) transposition
3) interpolating flap
What consists the rotation flap?
rotation flap requires creation of a semicircular incision and moving the tissue laterally to cover the defect
What consists the transposition flap?
rectangular, single-pedicle flap that is created adjacent to a defect and subsequently rotated on its pedicle is called a transposition flap (
Transposition flap can be rotate how many º?
180º
Figure 25-12. Transposition flap. This rectangular pedicle flap can be rotated up to 180 degrees to cover a defect.
What is a interpolating flap?
Moving a similar rectangular flap onto an immediately adjacent defect (i.e., the pedicle bridges an intact portion of the skin) creates an
The use of a rotating flap has been described in the management of a wound in a horse. Where?
In the craniolateral aspect of the tarsus of a horse
Figure 25-13. Interpolating flap. (A) A pedicle flap is lifted from the skin adjacent to the defect. (B) The flap bridges normal tissue to cover the defect. (C) After the defect has healed, the pedicle is resected and the incised edges are sutured.
Vascularized free tissue transfers have been attempeted as a natural progression to axial pattern flaps with well defined arteriovenous supply. Mention some of the arteries
in the horse include those perfused by the :
1) caudal superficial epigastric artery,
2) the medial saphenous artery,
3) branches of the deep circumflex iliac artery,
4) branches of the superficial temporal artery,
5) dorsal and lateral nasal arteries,
6) thoracodorsal artery,
7) suprascapular artery,
8) linguofacial artery
