Wound Closure and Suture
Technique
Gary
D. Monheit, M.D.
Associate Professor
Department of Dermatology
University of Alabama at Birmingham
Birmingham, Alabama
The
purpose of suturing is wound closure. Ideally, suturing should approximate
the wound edges so that the tissues can reestablish closure with a final
scar that is functional and aesthetic. The method and techniques of
suturing as well as materials used are determinants in the final outcome.
The surgeon must also have a full understanding of wound healing, tensile
strength, and wound closure to perform skin approximation. Ideally,
the wound should be approximated with little tension and the skin edges
handled gently. It is the fine attention the surgeon gives to handling
skin edges and the techniques of approximation that create the optimal
aesthetic scar line. This chapter will review the techniques and materials
available for suturing wound closure.
The history
of dermatologic surgery begins in the ancient world where evidence of
surgical wound closure is found in the Edwin-Smith Papyrus relating
methods of suturing and dressings. The document relates a deep facial
wound which was closed with silk sutures and covered with linen dressings
and ointments.1
Wound
closure was also noted in ancient Indian sanskrit texts describing suture
material made of animal sinews, bark, leather straps and even ant pincers.
The importance
of cosmesis in wound closure was noted by the Greeks and Romans with
the first description of layered closures, local flaps and pedicles.
Galen referred to the usage of catgut and silk suture material for closures
and as vessel ligature. The principles of antiseptics by Lister later
enabled sterile wound closures to progress to the modern era for fine
cosmetic dermatologic surgery.
The Materials
Needle and Suture
All surgical needles have three basic components; the point, the body,
and the swage.2 Most all sutures used in dermatologic surgery are directly
attached to a surgical needle rather than threaded through a hole. The
swage is the tail of the needle connecting the suture. The suture is
inserted into the hollow end of the needle and is mechanically crimped
to hold the suture securely in place. The swage is the broadest point
of the suture. The tip of the needle is the fine delicate point which
pierces the skin. The remaining portion where the needle is grasped
with instruments is the body. The needle body can be round, triangular,
or oval and may have ribs for grasping. Most needle bodies have an arc
of either 135 (3/8 circle), or 180 degrees (1/2 circle).3 Either of
these configurations can be helpful for various suture techniques. For
deep closure in which both fascia and subcutaneous tissue must be grasped
to close dead space, the 180 degree needle is helpful. It is also helpful
when suturing in cavities in which the arc of closure needs to be smaller
to bring deeper tissue together. The 3/8 circle, though, seems easier
to handle for basic skin closure on an open surface.
The needle point is a triangle with three cutting surfaces. A conventional
cutting needle has the third cutting edge of the triangle on the inside
surface of the needle arc. This places the apex of the triangle facing
the wound. The reverse cutting needle has the triangular tip pointing
away from the wound edge or on the outside of the arc. This creates
less cutting with tension on the suture line.4 For fine plastic closures,
reverse cutting is advantageous. Needles also differ as to material
and needle sharpness, and are coated by the major companies as for usage
and durability. F.S. (for-skin) is least expensive and for non-cosmetic
skin closures. The P, PS and PC refer to plastic, plastic skin, and
precision cosmetic needles which are made of higher quality steel and
honed to a sharper point. The dermatologic surgeon can choose which
of these materials best suits his needs in areas of wound closure. For
example, a PS or PC needle should be used for fine facial skin closure
while an FS needle is sufficient for suture closure on a covered area
of the body.5
Suture
Material
Suture material is generally divided into two types, absorbable and
non-absorbable. Each has a distinctive role when used properly for wound
closure techniques. Ideally, wounds are closed under minimal or no tension
so that skin edges can be directly approximated and sutures placed for
five to seven days. Absorbable suture will be digested by enzymes or
hydrolysis and, thus, do not need to be removed from the closed wound.
These are placed normally in fascia, subcutaneous tissue, and deep dermis
to close defects and take skin tension off the skin surface edges. After
skin tension is fully removed, permanent sutures are used to approximate
the skin surface for precise coaptation of the epidermis. Permanent
surface skin sutures should be removed within five days to reduce the
incidence of tunneling or skin tracts which occur as the epidermis grows
around the suture tracts. Prompt removal of these permanent sutures,
though, can only be done if the tension is alleviated by buried absorbable
suture which will maintain the strength of the wound edge until collagen
synthesis has been completed and the scar line is stable.6 It is, thus,
the surgeon's knowledge of suture material and wound healing to give
the best combinations for wound closures in various parts of the body.
A. Absorbable
suture material is used in the deep dermis and subcutaneous tissue to
reduce skin tension. The ideal absorbable suture material will retain
tensile strength until collagen replacement is complete and will remain
non-reactive until fully absorbed. None of the materials used are fully
non-reactive and the tensile strength diminishes with time. Absorption
time also is not consistent with loss of tensile strength and some material
remains reactive for months after tensile strength has disappeared.
Other factors the surgeon must consider are tieing ability, drag in
the tissue, and stability of knots in deeper tissue.
1. Catgut
Plain gut or chromatized catgut is an organic substance derived from
the serosal layer of cattle intestine or submucosal layer of sheep intestine.
The material is treated to become purified collagen which will be totally
digested in sixty to ninety days. Because gut is derived from an organic
material, chemical composition is uneven and, thus, its tensile strength
and ability for breakage varies through the suture. In many instances,
there are weak spots, uneven absorption and suture breakage which must
be taken into account. It induces an intense inflammatory response destroying
most of its tensile strength in seven to ten days and virtually has
no strength within two weeks. It is absorbed by inflammation and phagocytosis
as a foreign body. It should not be placed in contaminated wounds as
it forms a nidus for bacterial infection to spread, creating suture
abscess and tunnels. The advantage, basically, of this suture is that
it is inexpensive, it ties easily and is readily available.7
Chromatized gut has been process with a chromic salt to retard absorption.
This seems to reduce the inflammatory response but does not prolong
the tensile strength of gut suture to any significant degree.
2. Polyglycolic
Acid (Dexon)
This is a synthetic polymerized material of glycolic acid which is braided
into a polyfilamentous suture material. It appears less reactive than
catgut, retaining greater tensile strength during healing. Fifty percent
of its tensile strength is present in two weeks and twenty percent still
remains present in three weeks. It is absorbed by hydrolysis rather
than an inflammatory reaction which occurs in thirty to sixty days.
In this process of hydrolytic degradation, there is less inflammation
but a foreign body reaction and "spitting" through the epidermis
can still occur. The suture material ties easily but the braided suture
can catch tissue as it passes through skin and subcutaneous tissue.
This tissue drag can be cumbersome with buried knots and limit the surgeon's
ability to place the suture accurately in the depth of the skin. Because
of its polyfilamentous character, it also can trap bacterial and be
a nidus for infection.8
3. Polyglycan
- 910 (vicryl)
Polyglycan - 910 (vicryl) is a coated polyfilamentous synthetic polymer
of glycolic and lactic acid. It is similar in basic structure and function
to polyglycolic acid suture but is coated for easier passage in tissue
and more accurate knot tieing. It has a similar tensile strength and
absorption time and is degraded by hydrolysis with less inflammation
than catgut suture. Its tensile strength seems to be reliable maintaining
sixty percent in two weeks and thirty percent in three weeks. It also
is polyfilamentous and has some tissue drag, though its outer coating
makes it easier to use than polyglycolic acid suture. It, though, also
has the risk of spreading infection inherent in braided suture.9
4. Polydioxinone
Polydioxinone and maxene glycolic acid suture is a monofilament absorbable
suture with long retained tensile strength and slow absorption. It appears
to be less reactive than polyglycan suture with a two week tensile strength
of seventy percent. Being a monofilament, it slides more easily through
tissue and it is easier for deep tissue knot tieing.10
The choice of the appropriate absorbable suture depends on location,
skin type, the nature of surgical defect, and stress on the wound edges.
Each of these factors plays an important role in determining the absorbable
suture most useful to reduce skin tension for a particular wound closure.
B. Non-absorbable
Suture
Non-absorbable suture is used to close skin defects through the surface
with little or no skin tension. The puncture of the epidermis and dermis
with the suture material will produce a tunnel or tract that if left
in place for a period of time longer than epidermal regeneration, will
create skin tracking or permanent spots along the scar line. On the
other hand, removal of a permanent suture where tensile strength is
not great enough to preserve the wound closure will create a stretch
scar or even worse, a dehiscence. The appropriate choice of non-absorbable
suture and time for suture removal is important in surgical planning.
1. Silk
Silk suture has been important in skin closures for many years and set
apart as the standard for skin closure. This braided suture is easy
to handle and tie but does have a significant amount of tissue drag.
Though it is classified as a permanent suture, it is eventually degraded
by inflammation if left for long periods of time. It is, though, best
removed within seven days as it produces a significant inflammatory
reaction. Because the suture is braided, it is comfortable to use in
creases of the body, mucosal surfaces, and around cutaneous orifices
in which monofilament suture has an uncomfortable feeling during wound
healing.11 It cannot be used in infected wounds because its polyfilamentous
nature traps bacteria.
2. Nylon
Suture
Nylon suture is a non-absorbable monofilament which has low tissue reactivity
and high tensile strength. It appears as either a single monofilament
or multiple braided filaments,both of which tend to pass through tissue
easily. It, though, has a tendency to return to its original state,
a feature called memory which may cause the suture to coil and the knots
to unwind and come loose during healing. Extra ties must be passed with
this suture for the security of interrupted suture ties.12
3. Polypropylene
Polypropylene (prolene suture) is a synthetic non-absorbable compound
created as a monofilament suture with a tensile strength equivalent
of nylon and less reactivity. It is easier to handle than nylon because
of an intrinsic stretching ability as it passes through tissue easily
and ties well. It, though, also has memory which can create slippage
and knots to untie.12
4. Polyester
Polyester sutures are made from tightly braided multifilamental fibers
which have been shown to last indefinitely in the body surface. They
have come under the brand name of Mercylene, Ethybond, and Novafil,
a polybutester. These sutures are easy to handle with good knot tieing
ability and little problems with recoil or memory. There is some tissue
drag because of its braided nature and this is by far the most expensive
suture on the market.4
5. Surgical
Staples
Staples afford a convenient and easy method for wound closure in covered
areas of skin such as the scalp and selective areas of the trunk. It
can grab a large bite of skin and tissue and evert the skin edges facilitating
wound closure. It, though, produces staple marks as permanent scars
and should not be used in cosmetically important areas of skin such
as facial closures. Staples can be uncomfortable in body areas of pressure
such as buttocks or groin.
Surgical
Instruments for Wound Closure
The standard instruments used for wound closure include a needle holder
or driver, tissue forceps, skin hooks, needle forceps, and suture scissors.
These tools vary in size, material and shape depending on their usage
for wound closure. Matching the appropriate instruments with the needle
size and suture material as well as the defect to be closed is essential
for good surgical work. For example, a 6 mm. eyelid defect should be
closed with 6-0 prolene suture, a delicate Castroviejo needle holder,
and .5 Adson needle holder. The use of these delicate instruments with
larger suture and needles may bend instruments and damage them. Thus,
the surgical instrument must be correlated to needle and suture size.
The standard needle holder has a ratchet locking mechanism that stabilizes
the needle securely in its jaws. The needle holder should be locked
on the first ratchet and not beyond as this indents the needle and damages
the holder. The needle should be grabbed 3/4 distance along its body
for accurate stabilizing. For most facial skin closures the delicate
ratchet locking Webster needle holder made of stainless steel with a
carbon bite aids the surgeon in accurate suture placement. Larger needle
holders conventionally used in general surgery are awkward, cumbersome,
and inhibit good cosmetic work.
Tissue forceps should delicately grasp skin edges with little or no
trauma to the wound surface. Flat forceps compress and squash skin edges
creating ragged scar lines. The Adson tissue forcep creates less trauma
but still pinches the skin edge with pinpoint trauma. The most delicate
of tissue forceps is the Brown-Adson with its fine tooth-like projections
which can delicately move the skin edges with little compression or
tissue necrosis.
The most delicate instrument, though, is the skin hook which can both
pull and push tissue with little or no trauma. One needs dexterity and
experience to use this instrument carefully and the danger of skin puncture
to the surgeon is present if one is not careful. It behooves the good
dermatologic surgeon to learn the techniques to use this instrument
properly for good cosmetic closure.
Suture scissors can either be of the iris type or hooked variety. What
is necessary is that the scissors should be able to cut the suture cleanly
near its tip. This should work as effectively for buried suture in subcutaneous
tissue and skin sutures. Undermining tissue scissors should not be used
to cut suture. Monofilament suture and the synthetic nylons will dull
tissue scissors and make them ineffective instruments for undermining.
thus, the basic instruments on a typical repair tray should include:
1. Webster needle holder
2. Single or double pronged sharp skin hook
3. Brown-Adson tissue forceps
4. Needle forceps
5. Metzenbaum curved undermining scissors
6. Suture scissors
7. Bard-Parker handle with #15 and #11 blades
Suture
Technique
Proper use of sutures to close surgical wounds takes planning prior
to the surgical session to elevate the levels of closure. What will
the depth of the wound and the resultant tension on the skin edge do
to the final scar line? A simple closure is the use of direct interrupted
non-absorbable skin sutures to close the wound with interrupted sutures.
A layered closure entails buried absorbable sutures and interrupted
permanent skin sutures. A complex closure involves the essentials of
layered closures along with methods to reduce skin tension such as undermining
and tissue transfer.13 The surgeon must evaluate his excision and then
his defect as to the anatomic site and the nature of skin tensions for
the appropriate closure. Each of these will be reviewed in the general
concepts of wound closure. Interrupted suture closure is the simplest
and easiest method to close uncomplicated wound defects. To use interrupted
suture as the primary mechanism of closure, the defect must be:
1. A skin defect extending to subcutaneous tissue but without dead space
or a deep tissue defect.
2. Little or no skin tension on the wound edges.
An interrupted
suture is placed through opposite wound edges, full thickness through
the skin, to bring the wound edges together. The technique is accomplished
as follows:
1. The needle is grasped with the needle holder 3/4 length along the
body of the needle and the needle tip is then pointed perpendicular
to the skin surface. It is usually placed 1-2 mm. from the wound edge
and the point pierces through epidermis and dermis. This is accomplished
with a rotational thrust beginning perpendicular and extending in an
arc outward to subcutaneous tissue. At this point, the surgeon feels
a pop of the needle through the dermis as it advances into subcutaneous
tissue.
2. The arc of the half circle is continued through subcutaneous tissue
below the deepest point of the defect and then advances to the dermis
of the opposite side perpendicular to the plane of the skin surface
and emerges the same distance from the skin edge as the entrance point,
1 to 2 mm. As the surgeon sees the needle tip emerging through the skin
surface, it can be grasped with needle forceps by an assistant and pulled
through the surface. It is important that the needle be pulled through
either by an assistant or the surgeon with its opposite hand so that
it will not fall back into subcutaneous tissue when tension is released.
3. The surgeon then pulls the needle through all the way advancing the
suture through the wound so that 1 to 2 cm. of suture remain on the
opposite side. Grasping the end of the suture with a pair of forceps
and the opposite side with a needle holder, the surgeon can test the
closure tension along the skin edge. Ideal closure tension should advance
the skin margins together but not crush tissue within the suture. The
point of pressure is tested prior to tieing the surgeon's knot.
4. The surgeon's knot is accomplished as a double square knot. The square
knot is the fundamental knot used and when placed properly, it will
lie flat on the skin surface and maintain its position without slipping.
To tie the knot, the surgeon pulls the long end across the skin edge
and the needle holder is brought across the wound edge and the long
end is looped twice along the end of the needle holder. The needle holder
grasps the end and the two loops are brought into approximation. A single
loop is then placed over the double loop tie and this is placed securely
over the double loop. An additional single loop in the opposite direction
is placed over the second single loop, making a square knot. As the
last loop is tightened, the knot is then approximated and further pressure
will not put any further tension on the wound edge.14
The advantages of interrupted sutures for simple closures is the ease
and simplicity of the procedure. The risks are small and it provides
stability for the wound edges during healing. Disadvantages include
inversion of the suture line if the suture is placed too superficial.
That is, if the tension pull across the suture line is too superficial,
it will pull the scar line downward creating a trough. The other disadvantage
is the railroad tracking or scar tunnels left by the suture if kept
in for the five to seven days necessary for wound healing.
Vertical
Mattress Sutures
The vertical mattress suture is used to accentuate eversion when there
is significant skin tension and to close dead space in deeper tissue
defects. Vertical mattress sutures can be placed in conjunction with
interrupted sutures to ensure significant wound closure tension and
evert the skin edges. Between these, interrupted sutures are placed.
The vertical mattress suture is begun 0.5 to 1 cm. from the wound edge
with the needle pointed vertically to the depth of the wound, then under
the wound and back out along opposing sides equidistant from the wound
edge. The needle is then reversed, the skin is penetrated again on the
same side but closer to the wound edge and at this point, passes more
superficially through dermis to the opposite side exiting the same distance
from the wound margin, 1 to 3 mm. from the wound edge. The sutures are
then pulled together bringing the wound edges together and at the same
time, obliterating dead space and everting the wound edge. Care must
be taken to place the right amount of tension on the suture edge so
as to close the defect without crushing tissue and skin caught within
the suture. Excessive pressure at the depth of the wound can cause ischemic
necrosis and strangulation so, thus, it is important to minimize wound
tension prior to tieing the knots. This is a strangulating suture with
significant tension on the scar line. Thus, the vertical mattress suture
is rarely used on the face because it does produce scarring. Other methods
of reducing tension such as buried suture with fine approximating sutures
are reserved for facial closures.
Horizontal
Mattress Suture
Horizontal mattress sutures are used for minimizing wound tension, closing
dead space, and further exaggerating wound edge eversion. Areas with
significant wound tension such as the back, the chest, and the scalp
may need a horizontal mattress suture to ensure that tension is reduced
during healing. On wound closure, one or two horizontal mattress sutures
may be used in conjunction with interrupted sutures to approximate a
wound edge properly. With a horizontal mattress suture, the needle penetrates
the skin 1/2 to 1 cm. from the wound edge and passes vertically to the
depth of the defect across the depth of the defect then back out along
the opposing side the same distance from the wound edge. It re-enters
at the same distance from the wound edge and passes vertically to the
depth of the wound and back out along an equidistant space on the opposing
side. The double square knot is then used to tie this off, being careful
that tension will approximate the skin edges and is not too great. This
is a strangulating suture as the vertical mattress suture, and can crush
the tissue with tension. A bolster may be used with the horizontal suture.
Layered
Closure
A layered closure is the use of buried absorbable sutures in fascia,
subcutaneous tissue, deep dermis, combined with the use of buried absorbable
suture in deeper skin and tissue removes the tension from the skin edge
and provides stable reduction of closure tension during healing. To
perform this correctly, the wound must be prepared. This includes undermining
the skin a minimum of 2 mm. and, at times, up to 1 cm. beyond the wound
edge to reduce skin tension and for the accurate placement of the buried
absorbable suture. Meticulous hemostasis has been accomplished prior
to suture placement. The type of buried suture used depends on the thickness
of the defect, the tension on the wound, and the amount of dead space.
The buried subcutaneous suture or the dermal subdermal stitch is begun
first to the deep side of one of the undermined edges of the defect.
This is accomplished by lifting the wound edge with a skin hook and
advancing the needle tip 1 or 2 mm. from the wound edge on the undersurface
of the skin. This allows the suture pathway to proceed upward through
subcutaneous tissue entering into mid dermis. It will then pass through
the wound margin at mid dermis and reenter the opposite wound side through
mid dermis proceeding in an arc downward to the opposing subcutaneous
tissue and exiting 2 or 3 mm. from the wound edge. The suture lines
are then tied with the knot pulled along the long axis of the defect.
This allows the knot to slide to the base of the defect in the subcutaneous
tissue, burying the knot. Pulling the suture line perpendicular to the
scar line will trap the suture upward creating an inadequate closure
and a knot placed too high. Multiple buried subcutaneous sutures are
placed along the defect reducing tension along the skin edge at critical
points. This will then allow the placement of single interrupted sutures
with no tension on the skin edge, minimizing scarring. It also stabilizes
wound closure so that the interrupted suture may be removed in under
seven days, producing a better cosmetic result. It also lessens the
risk of surgical dehiscence when the interrupted sutures are removed.
The buried absorbable suture will maintain closure tension during healing.
Layered closure using buried sutures is a useful technique for skin
closures and this author feels it can be used in most areas of the skin
surface. Dangers with buried sutures include foreign body reaction,
strangulation of deep tissue with necrosis, local infection, and prolonged
inflammation.14
Chromic
suture has the highest potential for inflammation and possibilities
of secondary infection. This becomes increased if the suture is placed
high on the surface or the knot is wide enough to strangulate deep tissue
causing necrosis. If the knot is placed superficial with a significant
amount of inflammation, a persistent nodule can occur which may last
for months. It may cause suppuration with superficial necrosis and the
suture extravasating or spitting through the surface.15 Rarely, it can
induce scar tissue that will make a persistent nodule. Techniques to
prevent these complications include:
1. Choosing the appropriate suture material - both size and type.
2. Avoiding absorbable buried suture in wound closure that has the
potential for infection or already has bacterial contamination.
3. Placing the knot deep enough in the subcutaneous tissue to avoid
persistent nodules.
4. Keeping the tie small and sliding it to the base, avoiding
strangulation or necrosis.
After buried suture has been placed correctly, tension has been eliminated
from the skin margin. At this point, the skin surface can be draped
together and approximated with interrupted sutures. These can be removed
in four to six days because there is no tension on the skin margin.
It will, thus, be possible to avoid stitch marks along the scar line
by removing the sutures early.
Complex
Closures
Complex closures usually involve more extensive undermining and local
skin movement. Both of these preliminary closure techniques involve
a combination of suture techniques in the deeper dermis as well as on
the skin surface. Each of these closure techniques will be reviewed
in context to the clinical situation where it is most likely to be used.
The basis of these techniques depends upon reducing skin tension with
buried suture below the skin surface. This must be performed with fascial
sutures, buried subcutaneous sutures, and interrupted dermal sutures
to take the tension off the skin edge. It is only then that the variety
of running suture, running locking suture, tip stitch, and running subcuticular
sutures can be used for skin margin approximation.
Tip Stitch
The tip stitch is a modification of the horizontal mattress suture in
which half the suture is buried. It is used to secure and close acute
angles of closure with tips of skin that would be damaged by interrupted
suture. In this way, the suture travels through the dermis of the tip
and advances the tip with interrupted sutures on either sides. It, thus,
is used to secure the tip of skin flaps without compressing the epidermal
tissue and avoiding ischemic necrosis. Mechanically, the needle is passed
through the skin on one side of the V, exiting mid dermis and penetrating
the tip mid dermis and back out along the opposite side mid dermis.
It then will go through the opposite side of the V at a mid dermal level
and exit through the skin. As the suture is pulled, the tip will advance
into the V with enough pressure for good closure. It then is tied with
a double square knot. The tip stitch is useful in the closure of M-Plasties,
angles along transposition flaps, geometric broken line closures, and
Z-Plasties.16
Running
Suture
The running suture can be used to close skin edges in wounds in which
tension has been reduced fully. It is an approximating suture which
can simply and easily close a long scar line. Using permanent suture,
it is useful on body surface areas such as the retroauricular sulcus,
upper eyelids, and supraclavicular neck where skin grafts are harvested.
It can also be used for closures of body skin in which tension has been
reduced with interrupted subcutaneous sutures. In facial closures, a
running suture of 6-0 mild chromatized gut is used in conjunction with
buried subcutaneous sutures to reduce tension. The mild chromatized
gut suture, when placed under steristrips, will be absorbed in four
to six days. When the steristrips are removed, the suture is absorbed.
This will prevent suture marks or cross hatch scars and alleviates the
need for suture removal.
The running suture is initiated by placing a simple interrupted suture
at one end of the wound that is tied but not cut. Simple suture passes
are then placed down the length of the wound as a "baseball suture"
until the end of the suture line is reached. At this point, it is simply
tied off with a simple knot created by the last loop of suture. Running
suture shares tension along the closure line creating an even scar line.
It is an easy and rapid method of closing wounds and when used correctly,
it will create a cosmetically superior scar line. Performed incorrectly,
though, it can cause thicker tissue to bunch and pucker and if placed
too deeply, may create uneven edges. It can strangulate the epidermal
edge if pulled too tight and create an uneven, cross-hatched scar.
Running
Locked Suture
Locking the running suture as it is closed is a modification that will
counteract some degree of tension on the skin edge. It can be performed
as a locked suture for each pass or individualizing locked when needed
for areas of tension along the scar line. Additionally, it may help
prevent inversion of the wound edge which can account for an uneven
thickness in skin types. This suture technique is best performed with
an assistant who can grab the needle with each pass and place it back
in the surgeon's needle holder. It, thus, can be used efficiently for
both running and running locked suture lines. The major disadvantage
of this technique is that it may strangulate the skin edges creating
excessive scarring. This is overcome by taking small bites and keeping
tension on the suture line to what is minimally needed.
Running
Subcuticular Suture
The running subcuticular suture uses a permanent monofilament suture
placed as a horizontal running intradermal suture. The successful use
of this suture is dependent upon reduction of tension below the skin
surface with buried subcutaneous sutures. With skin tension removed,
the two skin edges then can be draped together and approximated with
a running subcuticular suture. The running subcuticular suture is begun
by placing the needle through one wound edge and enters into the defect.
The opposite edge is held firmly with a skin hook as the needle is passed
in a horizontal pattern through the mid dermis. It exits with a 1/2
cm. pass and then is brought in approximation to the opposite wound
side and enters the mid dermis. This is repeated on alternate sides
of the wound as the suture is advanced down the wound edge. It is then
terminated at the skin surface and then the surgeon can pull the monofilament
back and forth to adjust the tension correctly. Because the suture is
entirely below the skin surface, permanent monofilament suture may be
left in place for two or even three weeks without risk of skin marks.17
At that time, the suture can be removed promptly by pulling out along
the long axis of the scar line. Braided or silk suture should not be
used as a subcuticular stitch as this cannot be removed after two weeks.
The subcuticular suture is used primarily to enhance the cosmetic results
with defects in which tension has been fully reduced and the skin edges
are of relatively equal thickness.
Combined
Closure Techniques
A preferential approach to facial defects in which maximal cosmetic
results are necessary is to use as a complex closure the use of both
buried absorbable suture and permanent suture. Closure is performed
in a layered fashion with buried dissolvable suture in fascial layers
of subcutaneous tissue and buried dissolvable suture place in the skin.
Chromic suture or vicryl suture of 4-0 or 5-0 can be used depending
on the thickness of the skin and the location of the excision. Tension
should be fully removed from the skin with buried sutures so that the
permanent skin sutures placed for final approximation will not have
any tension or pull. This will reduce the incidence of suture lines
and cross hatches or stretching on the scar line. For further approximation
of an elliptical closure, 5-0 prolene suture may be used where tension
still exists on the skin edge. Dog-ears or skin redundancy at the tips
should be repaired at the time of closure and geometric points closed
with appropriate tip stitches. A final skin layer of 6-0 mild dissolvable
chromic suture is placed in the facial skin to further coapt the skin
edges together and level the sides equally. A running baseball suture
can be placed with no tension and ties at the ends. This mild chromic
suture or fast dissolving suture is occluded with steristrips. Since
this suture dissolves within five days, there will be no epithelial
channels on the skin to create cross hatches or suture marks when the
dressing is removed in seven to ten days. Being able to leave the wound
dressing for this longer period of time will enhance the stability of
the scar and lessen the incidence of dehiscence.
Anti-tension tape stripping is important for both occlusion and to take
tension off skin edges. These strips which are covered with narrow 1/2
inch flesh colored paper tape will create a stable wound bandage that
may be left in place for the entire week. This will also cover the wound
for protection and for cosmetic reasons during healing.
Techniques of suture and wound closure, thus, are essential for good
dermatologic surgery. Though many of the techniques appear basic, a
thorough understanding of these techniques is essential for the dermatologic
surgeon to close wounds correctly.