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Grafting andMicrografting
https://t.me/medicina_free
inWound Care
AlbertoBolletta, DavideDi Seclì, MircoPozzi,
andEmanueleCigna
37
37.1 Introduction
Chronic wounds represent a challenging problem
and wound care is becoming of primary importance for plastic surgeons. Many strategies have
been tested to treat chronic wounds, such as
advanced wound dressings, negative-pressure
wound therapy (NPWT), and surgical procedures, with good results in terms of enhancing
the healing process.
The use of autologous skin grafts, either full
thickness or split thickness, represents a valuable
option in wound healing, even though the extension of donor sites is limited. Allograft and xenograft, but also tissue-engineered articial skin,
provide prompt but temporary coverage. An ideal
graft should be immediately available, nonimmunogenic, permanent, and associated with
low morbidity [1].
As previously stated, autologous skin grafts
represent a good choice in wound care, as they
are immediately available and non-immunogenic,
but donor areas for skin grafts are limited, even
when meshing techniques are used.
The use of micrografts, on the other side,
offers all the aforementioned characteristics as it
is autologous tissue, immediately available for
coverage, which uses a minimal amount of donor
skin [1].
37.2 Skin Grafts
37.2.1 History
Skin grafting is an important technique in reconstructive surgery, being an essential procedure in
patients who have suffered burns, traumas, and
non-healing or large wounds.
It was rst described in India approximately
3000years ago, where full-thickness grafts harvested from the gluteal region were used for nasal
reconstruction after amputation.
The use of this surgical technique was introduced in Europe in the nineteenth century: in
1817, Sir Astley Cooper used a full-thickness
skin graft from an amputated thumb to provide
coverage for the remaining stump. In 1823,
Buenger performed a successful nasal reconstruction using a skin graft. In 1874, a fullthickness skin grafting procedure was published
by Wolfe and made popular by Krause, so the
technique became known as Wolfe-Krause [2].
A. Bolletta (*) · D. Di Seclì · M. Pozzi · E. Cigna
Unit of Plastic Surgery and Microsurgery, University
of Pisa, Pisa, Italy
© The Author(s), under exclusive license to Springer Nature Switzerland AG 2023
M. Maruccia et al. (eds.), Pearls and Pitfalls in Skin Ulcer Management,
https://doi.org/10.1007/978-3-031-45453-0_37
37.2.2 Classication
A skin graft consists of the entire epidermis with
a dermal component of variable thicknesses. If
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Fig. 37.1 Manual dermatome is used to harvest splitthickness skin grafts
the entire thickness of the dermis is included, the
graft is known as full- thickness skin graft (FTSG).
If not, the graft is referred to as a split-thickness
skin graft (STSG).
STSGs are then classied as thin (0.005–0.012
in), intermediate (0.012–0.018 in), or thick
(0.018–0.030 in), based on the thickness of the
graft [3] (Fig.37.1).
The choice between a split- or full-thickness
skin graft for wound coverage depends on many
factors, including contraction, location of the
wound, type of wound, and size of the graft.
Contraction represents an important factor in
the healing process of skin grafts. Primary contraction is caused by elastin bers within the dermis and occurs immediately after harvesting. The
amount of primary contraction that a graft experiences is proportional to the amount of dermis in
the graft; therefore full-thickness skin grafts
exhibit more primary contraction than splitthickness ones.
Secondary contraction is a process that occurs
during graft healing and its rate is higher in grafts
with a thinner dermal component. Secondary
contraction can cause signicant limitations in
the stretch and mobility of the graft; therefore,
full-thickness grafts are the rst choice in specic areas such as joint surfaces. After healing,
grafts with a thicker dermal layer are more resistant to subsequent trauma.
The size of the graft needed is another
important parameter to consider before choos-
A. Bolletta et al.
ing the type of graft. When harvesting a splitthickness skin graft, the donor site heals by
secondary intention, whereas the harvest of a
full-thickness graft requires a primary closure
of the donor site. Therefore, the amount of skin
needed and the healing process of the donor
site should be taken into consideration: if a
larger skin graft is required, a split-thickness
skin graft would probably be the best choice.
Moreover, a split- thickness skin graft can be
expanded via meshing techniques. Another
aspect to consider is the fact that thicker skin
grafts have a greater metabolic demand on the
wound bed during healing. Thus, it is advisable
to choose split-thickness grafts in the management of chronic wounds [4].
37.2.3 Meshing Techniques
Meshing techniques can be used to expand the
surface of the skin graft. Many techniques have
been described: from a manual incision of the
skin graft using a scalpel blade (No. 11) to a
hand-powered meshing device (mesher). The use
of meshers is the most common and preferred
technique. The mesher applies multiple slits at
regular intervals on the skin graft and in preset
ratios. Commonly used ratios include 1:1, 2:1,
3:1, and even 6:1. (Fig.37.2) Once meshed, the
skin grafts can be stretched, increasing the area
of coverage. The higher the meshing ratio, the
Fig. 37.2 A meshed split-thickness skin graft is used to
cover a large skin defect
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Fig. 37.3 Dressing over meshed split-thickness skin
graft with hyaluronic acid gauze
larger the area of the wound that can be covered.
But a higher ratio is also related to a longer healing time, due to the reduced area of the wound
covered by the meshed skin grafts. In meshed
skin grafts, in fact, holes are formed within the
graft between thin skin bridges, from which the
epithelialization process will start. These holes
allow uid drainage, preventing blood or serum
accumulation between the recipient wound bed
and the graft, which could cause graft failure [3,
5] (Fig.37.3).
37.2.4 Preparation oftheWound Bed
The characteristics of the wound bed are of
primary importance in the healing process of
the skin grafts. To avoid failure of the procedure, surgeons must prepare a suitable wound
bed. Debridement of the wound bed can be
performed using different techniques, such as
the scalpel, the dermatome, or the hydrosurgery device until the wound bed shows a
healthy bleeding tissue. Nonviable tissue must
be removed also from the wound edges. If the
wound bed is not clean, the skin graft cannot
undergo the normal healing process [6].
NPWT can be used to prepare the wound bed
before skin graft application, and also on the
skin graft to improve its survival (Fig.37.4).
Fig. 37.4 The possibility of applying negative-pressure
wound therapy over the skin graft in order to improve
graft survival
37.2.5 Indications fortheUse ofSkin
Grafts
Skin grafting is a fundamental element of reconstructive procedures. It is usually performed
when a simpler method of wound closure, such as
secondary wound healing or primary closure, is
not indicated [5–7]. The use of skin grafts is a
safe and simple procedure in patients with large
wounds that would otherwise be difcult to treat.
Reestablishing skin continuity is essential to prevent infections and reduce uid loss, as well as
allowing the patient to return to everyday activities. Split-thickness skin grafting is the current
gold standard for the treatment of traumatic
losses of skin, especially in burn injuries [8, 9]. In
fact, the use of skin grafts is associated with
reduced wound contraction and extracellular
matrix deposition, compared to non-grafted fullthickness wounds [10]. Requirements for skin
grafting include an available donor site and a
recipient site that is well-vascularized and clean.
Typically, skin grafts are used to cover deep
partial- thickness skin defects and full-thickness
skin defects, or can be placed directly over muscles. However, skin grafts can potentially survive
on any wound bed with good vascularization,
including tendon with intact paratenon (forearm,
hand, ngers), cartilage with intact perichon-
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drium (ears), and bone with intact periosteum
(skull). On the other hand, if vascularized tissue
in the wound bed is absent, the grafting procedure will fail [7].
37.2.6 Contraindications
Contraindications to the use of skin grafts are
limited. Active infection, active bleeding, and
persistence of cancer are absolute contraindications to a skin grafting procedure. Also, wounds
with exposed bone, tendons, nerves, or blood
vessels without appropriate coverage by a vascularized tissue represent a contraindication to the
use of skin grafts. The location of wounds over
joints or key anatomical areas, in which contraction could reduce mobility and/or aesthetic
appearance (i.e., wrist, elbow, eyelid), can be
considered as relative contraindications.
Surgeons should consider individual factors
such as tobacco use, chronic steroid use, malnutrition, or previous radiotherapy on a case-bycase basis [10].
37.2.7 Epidermal Grafts
The harvest of a split-thickness skin graft determines a variable donor site morbidity, as the
donor site usually heals by secondary intention,
and the process may take a longer time, with a
risk of infection and hypertrophic scarring.
Epidermal grafting (EG) is an alternative method
of autologous skin grafting which requires the
harvesting of only the epidermal layer of the skin.
Dermatologists rst used epidermal grafting in
1964 and subsequently for the treatment of
hypopigmented lesions.
EG is obtained by applying continuous negative pressure on the normal skin to raise blisters
[11]. The roof of the blister, which is the epidermis, is then excised and transferred onto the
wound. As the dermis in the donor site remains
intact, the skin regenerates without scars. This
procedure is also painless as the pain bers in the
dermis are unstimulated, allowing autologous
skin grafting in the outpatient setting without the
administration of anesthesia and with minimal
donor site morbidity [12]. The epidermal grafts
are commonly used to treat chronic wounds. EG
promotes wound healing by expressing growth
factors that accelerate wound healing and the
migration of cells from the wound edges [11].
37.2.8 Wound Healing andFat Graft
Chronic wounds are one of the most challenging
conditions for plastic surgeons and have been a
topic of great interest in the eld of regenerative
medicine for years. Recently, the focus of regenerative medicine has moved to fat grafting as a
healing procedure, being able to promote faster
wound closure and pain reduction. In reality, free
fat graft autotransplantation is an old topic in
plastic surgery: since the nineteenth century, fat
grafting has been used in the treatment of a variety of soft-tissue defects. An important role in the
healing process was given to a “broblast-like”
cell of mesenchymal origin, called pre-adipocyte,
which was able to differentiate in adult adipocytes when replanted [13]. An important breakthrough in this eld was given by Coleman in the
late 90s, who described the principal technique
to harvest an adequate amount of fat tissue able to
guarantee its survival after grafting [14]
(Fig.37.5).
During the last 15years, scientic investigations on the use of fat tissue as a bioactive material through fat grafting or micro/nano-fat
techniques have signicantly increased, gaining
an important role in wound treatment.
Nowadays it is known that most fat graft
regenerative capacity depends on the autologous
adipose-derived mesenchymal stem cells
(AD-MSCs), typically suspended in the stromal
vascular fraction (SVF) of fat tissue. AD-MSCs
have a multi-potent differentiation potential and
can proliferate and differentiate into skin cells
(endothelial cells, dermal broblasts, and keratinocytes) and mediate tissue regeneration and
wound healing, via paracrine and autocrine pathways [15].
The biological properties and the capability of
AD-MSCs to differentiate and interfere with the
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Fig. 37.5 Decantation after fat graft harvesting. The separation of fat components is noted: blood and uids are
located on the lower part of the syringe, while the upper
part is mainly composed of fat
wound healing process are modulated by the
microenvironment of the tissue, through the
action of different cytokines: AD-MSCs act on
amplifying broblasts, macrophages, and skin
cells via the secretion of growth factors (TGF-β
and GDF11) and on promoting cell proliferation
and angiogenesis via VEGF, PDGF, and
IGF. TGF-β plays the most important role by
activating ADSCs’ differentiation, increasing
their ECM secretion, regulating melanin production, and more importantly, promoting the upregulation of GDF11, involved in accelerating skin
cell production and maturation after injury.
Moreover, in association with MMP-9, TGF-β
plays a key role in remodeling and wound closure
[16].
Multiple studies have veried the role of
autologous fat grafting as a procedure for the
treatment of diabetic foot: inltrations along the
edges and the wound bed have shown an improvement in the depth and size of the ulcers, and also
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an improvementin the surrounding skin conditions [17, 18].
On the same topic, further studies demonstrated how the application of platelet gel combined with centrifuged fat tissue in sequential
treatments can restore the supercial characteristics of the injured tissues [19]. Repeated sessions
of fat grafting may also improve dermal scars and
keloids, resulting from traumatic injuries or
severe burns: collected data suggest that fat grafting promotes epidermal cell proliferation associated with an improvement in the structure of
ECM (new collagen disposition and increased
vascularisation) and trophism of the local tissue,
which results in remodeling of the scar tissue
toward the quality of normal skin [20–22].
Moreover, recent studies have further analysed the role of the ultraltered fat graft injected
in chronic wounds in reducing pain: through the
secretion of growth factors that create a favouable
microenvironment, it seems that nerve regeneration is stimulated, with a resultant reduction of
pain and improvement in the patient’s quality of
life [23] (Fig.37.6).
Data available so far suggest a non-inferior
role of fat grafting compared to the standard
treatment of chronic wound healing. However,
further studies are needed in order to better evaluate the action of fat grafting and to dene standard protocols of treatment.
Fig. 37.6 Fat grafting in small aliquots into perilesional
skin promotes healing of a vascular ulcer of the lower
limb
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37.3 History andDevelopment
ofMicrografting Technique
The rst method of grafting small pieces of skin
was rst described by Jacques-Louis Reverdin in
1869 [1]. His method consisted of grafting small,
full-thickness pieces of skin to promote wound
healing. These little islands of skin would promote healing and epithelization of the wound.
The concept is that, by creating small skin islands
within the wound, a large area of the wound bed
comes in contact with an epithelial surface, promoting epithelial migration between micrograft
islands.
Since then, various techniques have been
developed, with many advantages and disadvantages, but nowadays the Meek technique represents the most popular and used technique of
harvesting micrografts.
37.3.1 The Pinch Graft
The pinch graft by Jacques-Louis Reverdin
(1869) represents the rst attempt at micrografting. It involves harvesting small pieces of skin,
only the epidermis, and applying them on the
wound bed, allowing epithelization from the
edges of the skin grafts and of the wound [1].
Pinch grafts were widely used for treating
chronic leg ulcers, but after the rise of splitthickness skin grafts, this technique was gradually abandoned.
This technique offers a simple and low-cost
strategy in wound healing, resistant to infections
and pressure, especially when the skin grafts are
harvested full-thickness, but it is associated with
a poor cosmetic result, due to the uneven disposition of the skin islands, and to the disadvantage
of a donor site that cannot be used again for
future grafts.
skin graft, from one-sixth to one-ninth the size of
the wound, placing the dermis up on a sheet of
sticky paper and then cutting it into strips. After
that, the skin graft is placed on another sheet of
paper and cut again horizontally into small
squares. This technique introduced the concept of
using a sheet of paper to help placing the skin
graft on the wound bed in a more uniform manner. Eventually, also the use of this technique was
gradually abandoned with the advent of meshed
skin grafts.
37.3.3 The Intermingled Technique
The intermingle technique is a procedure used to
cover extended burn wounds when skin donor
sites are limited. It was introduced in the early
80s. The procedure involves using allografts and
autografts together. The surgical technique consists of wrapping the wound with allografts and
then punching them, creating holes of about
1cm. After that, autografts are harvested and cut
into 0.25 cm2 pieces and placed into the holes
created in the allografts.
The procedure and healing process induced by
the intermingled grafts were later studied by
Yang etal. [24] and a particular phenomenon was
documented: the “sandwich phenomenon.” This
phenomenon is characterized by the migration of
the autograft in between the allograft dermis and
epidermis. After the migration, the allograft
degenerates, thanks to the endogenous process of
rejection, leaving the autograft intact, thus allowing, during the healing process, the protection of
the autograft. This procedure demonstrates less
contractures of the skin graft compared to the
other techniques, but it can be tedious and it can
be associated with the rejection of the skin graft,
due to the use of allografts.
37.3.2 Patch/Postage Stamp Graft
Another attempt at developing a micrograft technique was made by Gabarro in 1943. His technique, known as patch graft, consisted of using a
37.3.4 Microskin Graft
The microskin graft is a micrografting technique
developed by Zhang and co-workers [25–27]. It
involved the use of allograft and autograft, incorporating the theories behind the patch and the
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intermingled grafting. In this technique, after
harvesting the autograft, it is cut with scissors
into small pieces, smaller than 1mm3 and then
immersed in a saline solution, which theoretically allows the grafts to orient themselves with
their epidermal sides facing upwards. After that,
the skin grafts are put on a silk cloth and, lastly,
on a sheet of split-thickness allograft overlayed
on the silk cloth. The combined skin graft
(minced autograft and the sheet of allograft) is
allowed to dry for a certain period of time before
being transferred to the wound bed. The small
pieces of autograft are placed on the wound bed
without any regard for the orientation, because,
in the authors’ opinion, the skin grafts are so
small that they still have their dermal appendages
in contact with the wound bed, even if they are
placed with their dermal side up.
Although the technique is easy to perform,
cost-efcient, and provides resistance to infection and to trauma; it is associated with an
increased rate of contracture [28]; and to an
uneven orientation of the skin graft.
37.3.5 Microscopic Split-Skin “Diced”
Graft
The microscopic split-skin graft, also known as
diced graft, is a peculiar technique of harvesting
skin graft developed by Blair and co-workers
[29] with the particularity of creating an expansion ratio up to 26:1. The technique involves the
use of a histological tissue slicer that creates
diced graft of 200μm2 in surface. Then the diced
grafts are spread into the wound bed with a knife
and covered with a hydrocolloid dressing. A positive aspect of this technique is represented by its
possible and theoretical use in outpatient
settings.
37.3.6 Fine-Particle Graft
(Autologous Skin Suspension)
The autologous skin suspension represents a controversial technique of historical interest, originally described by Najarian and McCorkle [30,
31]. In this technique, a sheet of split-thickness
skin graft was reduced into small pieces with a
blender and then applied onto the wound bed of
an animal model (rabbit). It was applied, without
any difference in outcome, on granulation tissue,
fascia, or denudes skin and it demonstrated a
complete epithelization in 92.5% of the rabbits,
but hyperplastic, hyperkeratotic, and contractions
of the scars were noted, with poor cosmetical
results.
37.3.7 Micrograft Spray
This technique is an innovative method which
involves spraying micrografts onto the wound
bed after cutting the skin graft into pieces of 0.2–
0.5 mm in size, with a nal expansion of
110–150:1.
This technique showed a reduction of wound
healing time compared to conventional microskin
grafting (29.7days vs 37.3days, p<0.05) [32]
showing various advantages such as a welldistributed graft, easy use, less donor site skin
needed, and the short operating time.
37.4 The Meek Technique
The Meek technique is probably the most popular micrografting technique and it was developed
by Cicero Parker Meek in 1958 [1, 33]. His idea
was to cover large wounds using less donor site
skin by cutting the skin grafts into small pieces.
His rst attempts were performed on burns
because of the lack of skin donor sites in these
patients. He invented also the Meek-Wall
Microdermatome to quickly cut into pieces the
skin graft after placing it on a cork carrier. His
technique, as he rst described it, was abandoned
with the advent of the meshed skin graft, published by Tanner etal. in 1964, but readopted and
improved in the 1990s [34].
The micrografting technique is indicated in
major burns (>30% TBSA) and where the donor
site for harvesting skin grafts is not available
[33]. Often, the expansion ratio required is more
than 1:6 and this kind of expansion cannot be
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reached with meshed skin graft. The limitations
of meshed grafts, due to the discrepancy between
the theoretical expansion rate and what is actually obtained after the procedure (probably due to
the shrinking of STSG and its elasticity) [35],
have raised the interest in the Meek Micrografting
technique.
According to a study by Kok etal. comparing
the “mesh” with the “Meek” technique, patients
treated with the latter underwent fewer surgeries
(10 vs 19.75), had a shorter length of hospital
stay (51 vs 120.5days), and less allograft used
for TBSA% burn (115.7cm2 vs 356.5cm2), with
an overall lower cost [36]. Moreover, a faster reepithelialization and a higher viability rate are
seen after the use of the Meek technique, compared to the mesh technique [36, 37].
Micrografting has a higher success on poor
wound beds, with infection or a poor vascular
supply. This is due to poor metabolic demand and
a greater skin coverage expansion ratio (1:12).
The disadvantage of the Meek technique
includes a “polka dot” appearance once healed
which is not seen in the mesh technique.
37.4.1 The Modied Meek Graft
Procedure
square pleats. The cork plate is then gently
removed, leaving the skin graft islands on the
gauze.
After that, the gauze is pulled from the four
angles, until the pleats become completely
unfolded and then the aluminum backing is
removed, leaving the expanded gauze with separated autograft islands ready for grafting. The
gauze is then applied, side down, on the wound
bed and secured with staples. It is removed only
after six days when the grafts have grown sufciently into the wound bed. After removal, the
wound bed with the skin islands is covered with
non-adherent sheeting to prevent any movement
during daily dressing changes, which continue
daily until re-epithelialization is completed.
The healing process in the micrografting procedure is driven by the proliferation and migration of the keratinocytes. Micrografts of a certain
size (0.8×0.8mm) initially survive by the diffusion of uid from the wound bed rather than neovascularization [33].
37.5 Fields ofApplication
ofMicrografts
37.5.1 Burns
The Meek technique, as he published it in the
1950s, was later modied. The modied Meek
technique was rst published in 1993 by Kreis
et al. [33, 38]: it involves the harvesting of a
split- thickness skin graft which is placed, after
being sprayed with a special glue, on a cork
plate of 42×42mm, dermal side down. Then, it
is soaked with 0.9% saline solution and placed
in a cutting machine that contains 13 circular
blades. The cork plate passes through the
machine which cuts the graft but not the cork
plate. After this rst step, the cork plate is
rotated 90° and passes again through the cutting
machine. What is obtained is 196 square pieces
(14×14) of the skin graft. The epidermal surface of the graft is then sprayed with a special
glue and allowed to dry for 5–10min. Then the
cork plate is pressed onto a prefolded polyamide
gauze on an aluminum foil backing into 14×14
Major burns represent dangerous injuries associated with high disability and mortality. Survival
rates in major burns in low- and middle-income
countries are compromised by a decit of autograft donor skin to obtain denitive wound coverage [39].
The principal treatment of burns is the timely
removal of necrotic tissue and effective wound
closure, but usually, when burns are extended,
there is a lack of autologous skin. Burn environment, in fact, is suitable for bacteria growth and
the necrotic tissue in the wound tends to stimulate the production of a variety of inammatory
mediators, which can cause many complications
(internal disorders, wound infection, shock). In
this case, prompt debridement and skin grafting
to achieve wound healing reduce the risk of infection and help maintain the organ function,
improving the outcomes [40].
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Standard meshed grafts require the presence
of approximately an equal surface of the donor
site to cover the burn wound and some sites are
inappropriate as donor sites (face and hands).
In this scenario, the use of the Meek micrografting technique offers an alternative to cover
large areas in the absence of other forms of coverage. It is a reliable method to achieve wound
healing, reaching greater expansion ratio compared to meshed skin grafts.
The technique has been recently readopted
and its use in burn wound healing is of primary
importance especially when TBSA >30% and in
children.
The use of this technique and its elds of
application have been studied by many authors. A
retrospective study by G.Hu etal. evaluated the
efcacy of the two-stage Meek micrografting
technique comparing it with the one-stage procedure in patients with severe burns. In this study,
prompt micrografting after an early debridement
was compared with delayed micrografting after
several days (3–5) of early debridement and the
results showed a signicantly higher survival rate
of the two-stage Meek grafting than that of the
one-stage group. In the authors’ opinion, this is
due to a more adequate resuscitation in the twostage micrografting group, which contributes to
better wound preparation and higher levels of
serum protein and albuminemia.
Many factors can affect the survival of Meek
micrografting in burn wounds. Zhang etal. demonstrated that the burn severity index, Meek skin
graft area, duration of anesthesia, pre-operative
nutrition status, and post-operative infections are
important factors affecting the survival of micrografting. Albumin should be maintained at a high
level, infection should be actively controlled,
especially in the rst 1–3days after surgery and
operation time should be shortened as much as
possible [41].
37.5.2 Chronic Wounds
Chronic wounds can be dened as wounds with
multifactorial pathogenesis that do not follow the
normal healing process, remaining unhealed for
at least 12 weeks [42]. The healing process in
these wounds is completely different from acute
healing, as it underlies cellular dysfunction and
abnormal prolongation of inammatory and proliferative stages of healing [43]. Among chronic
wounds, non-healing ulcers, especially venous
ulcers in the lower extremity, occur very frequently [44].
The role of micrografts in the treatment of
ulcers has been demonstrated in several studies,
in which micrografts promoted the healing of
chronic leg ulcers of different etiologies, including venous, diabetic, and post-traumatic ulcers
[44]. In treating chronic wounds, the micrografting procedure can be used as an option, as it was
effective and less invasive than main grafting procedures [1].
A particular technique of skin micrografting
preparation has the objective of disaggregating,
in a mechanical way, autologous tissue, obtaining
pieces of skin of 80 μm. This approach allows
also the collection of autologous micrografts
enriched in progenitor cells, growth factors, and
particles of extracellular matrix derived from the
patient’s own tissue [44]. In vitro studies have
demonstrated that micrografts obtained mechanically by selecting particles with a cut-off of
80 μm show positive results for MSC markers
such as CD73, CD90, CD115, and CD146 and
negative results for hematopoietic markers such
as CD34 and CD45. These data support the
regenerative potential of micrografts, and several
studies have reported the ability of micrografts to
differentiate into chondrocytes, osteocytes, and
adipocytes [45–48]. In vitro studies have shown
that micrografts exhibit a broblast-like morphology when cultured, and have conrmed the
expression of MSC markers. When combined
with collagen sponges, micrografts can form a
viable and proliferative bio-complex, enhancing
their regenerative potential [49] and this is one
advantage of using a micrograft suspension.
Micrografts obtained by mechanical disaggregation of autologous tissue have also been widely
used in the management of post-surgical dehiscence. Post-surgical wound dehiscence can arise
as a complication in different types of procedures, such as the transplantation of the lung and
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kidney, colon resection, following a laparotomy
procedure with an incidence of about 0.5% and
gynecological procedures, such as Caesarean
section and total abdominal hysterectomy with
an incidence of 15%.
Orthopedic surgical complications can lead to
longer hospitalization, increased patient morbidity, and higher costs. Different studies showed
the effectiveness of treatment with autologous
micro-grafts in ameliorating the healing of postsurgical orthopedic dehiscence in patients who
previously underwent a primary surgical
intervention, such as tibial-tarsal fracture and
forefoot alignment, offering an efcient and
promising alternative to the already existing
approaches, to improve wound healing in patients
who exhibit wounds hard to heal. Another advantage, with respect to NPWT, is the fact that it
does not require dressing changes at 48 or 72h.
In fact, the application of micro-grafts is performed only once without particular precautions
or other dressings for the patient [50].
37.5.3 Treatment ofScars
Hypertrophic scars and keloids are aberrant
expressions of pathological wound healing with
an excess of extracellular matrix (ECM), mainly
driven by broblasts. Keloids and hypertrophic
scars pose a clinical challenge in scar-related cosmetic dysfunctions and are highly prevalent in
trauma and burns.
In the treatment of pathological scars, several
methods have been implemented to improve
hypertrophic scars using both surgical and nonsurgical approaches. The use of corticosteroids,
laser therapy, 5-uoruracil, botulin toxin A, and
Interleukin-10 are some examples. However,
identifying an optimal universal treatment for all
types of scars still remains a challenge.
Moreover, in the treatment of scars, autologous micrografts can be a new approach. A study
by Svolacchia et al. demonstrated the potential
efcacy of dermal autologous micrografts, used
alone, to treat hypertrophic and keloid scarring as
a result of burns or traumatic injuries [51]. The
authors suggest that the effectiveness of dermal
micrografts could be related to the immunomodulatory effect of MSCs, which secrete a combination of growth factors and cytokines to promote
wound repair. In fact, the combination of growth
factors and cytokines successfully induces angiogenesis, reduces inammation, and promotes
broblast migration and collagen production.
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