Section 2 Skin Grafting

## **Chapter 4** Types of Skin Grafts

*Verónica Olvera-Cortés*

### **Abstract**

Skin grafting is a useful technique that has been used for a very long time for achieving closure of wounds when it cannot occure in a natural conventional manner. There are different types of grafts according to their origin, thickness and form. There are 3 main types of graftsthat are used to cover wounds: Split-thickness skin grafts, full-thickness skin grafts and composite grafts. Each of them has specific indication and has a unique technique for harvesting. If the graft is not taken care of properly its survival can be compromised and necrosis of the graft can occur. Even though complications may present, skin grafting is still considered a practical approach to repair many type of wounds.

**Keywords:** Gratf, Skin, Non melanoma skin cancer, surgery, treatment

#### **1. Introduction**

A skin graft is a piece of skin of variable thickness without any vascular connection, separated from the donor site, and afterwards transposed over the recepient site which is to be repaired [1].

This technique was used initially in India about 2.500–3.000 years ago by Tilemaker Caste. It was later rediscovered inthe XIX century and was the most used technique during World War I and II. And in 1823 Buenger was the first to describe a succesful intervention by transfering skin from the buttcheek to the nose [1]. It is a basic technique and an option of reconstruction after a tumor resection, in case of ulcers and burned patients [1].

Skin graft execution is simpler than most skin flaps and can be performed in almost any wound with a vascularized bed. One of the great advantages of skin grafts is that they are very variable in size and shape to allow wound closure of wound defects of different sizes. There are many sites that can be donor sites making it easier for the skin to match.

#### **2. Indications**

Wound closure should always follow the principles of the reconstructive ladder, which directs the surgeon to use the least complex method of closure to achieve an ideal cosmetic result [2].

Often a graft may be used when healingof a full thickness wound by second intention, a primary closure, or utilization of a local flap are not feasible options [3].

In some instances, grafts can be used in combination with linear repairs or flaps for skin reconstruction surgery. In addition, skin grafts can be used for shallow defects, or in a patient with multiple morbidities who cannot tolerate a more complex or multi-stage repair [4].

### **3. Classification**

There are many ways in which skin grafts can be classified, based on their origin, thickness, composition, time in which they are performed, geometry and if it meshed or not (**Table 1**).

According to their origin, skin grafts can be divided in 3: Autografts, allografts and xenografts.

Autografts are taken from the patient's own skin, and they are the most common used skin grafts.

Allografts come from another person's skin. And xenograftsare derived from another species, other than human skin, for example porcine grafts. Both allografts and xenografts are used in chronic wounds or burn wounds. Their utility comes from their ability to stimulate wound healing, provide protection and achieve debridement [3].

In terms of thickness, they are distinguished as: Split-thickness skin grafts and full-thickness skin grafts [1] and composite grafts.

Split-thickness skin grafts are composed by epidermis and a variable thickness of dermis. They can be subdivided in 3 [1]:


Full-thickness skin grafts are composed of epidermis and dermis with skin appendages [1].

The amount of dermis in the skin graft determines many properties of the graft, such as resistance to pressure and shear forces, shrinkage, sensitibity and esthetic results. In other words, the thicker the graft the better mechanical, functional and aesthethic properties, but also this means that the neo and revascularization of the graft will be more difficult.

If the graft includes other tissue besides skin it is a composite graft. Composite grafts are made by two different tisular structures, skin and cartilage most of the cases [1].


According to the moment in time in which the graft is realized [1]:

**Table 1.**

*Classification of skin grafts.*

Immediate: Realized just after the resection of the tumor. To repair the loss of substance.

Differed: The graft is performed in a second intervention, in order to have the confirmation of clean margins. This approach is justified for agressive tumors and tumor relapse, to obtain granulation tissue when the surgery is extense in depth and/or width, and exceptionally when hemostasis of the reciepent site cannot be achieved [1].

Another way to classify skin grafts is based if a technique is used to expand the graft itself. If the skin graft is directly applied onto the defect without further treatment this is called an unmeshed or sheet graft [5].

A mesh graft is when multiple slits are made on the graft. Usually this is made with a mechanical mesher and it is common to apply this on split-thickness skin grafts. Meek graft is a skin graft that is cut in stripes, equal in lenght and width. It used a cork plate and a machine with rotating blades. Punch grafts are obtained using a punch, which allows to obtain multiple full-thinkcness skin grafts, it is a useful technique to cover large wound areas.

#### **4. Physiology**

The survival of skin grafts is a complex process that involves different phases. In order to undestand them it is necessary to remember how the skin is irrigated.

Skin consists of 2 basic layers, the epidermis and dermis. The dermis is divided into a papillary and reticular layer. Within the dermis resides the skin's neurovascular supply. The subcutaneous tissue beneath the skin contains the superficial fascia and subcutaneous fat [6].

The skin vasculature consists of a deep dermal/subcutaneous plexus and a superficial plexus [6]. Both plexi are connected via communicating vessels. The superficial plexus can be found in the reticular dermis, near its junction with the papillary dermis. The deep plexus, located in the subcutaneous tissue, consists of an extensive venous plexus, capable of holding large quantities of blood and an accompanying artery. The deep plexus supplies vessels to the pilosebaceous units and the superficial plexus. Arteriovenous anastomoses also exist in the region [6, 7]. The superficial plexus originates vascular loops within the papillary dermis. Nutrients diffuse into the epidermis because no vessels cross the dermal-epidermal junction. Venous and lymphatic systems exist in a similar arrangement [6].

Unlike flaps, grafts depend on the ingrowth of capillaries from the recipient site for their ultimate survival [8].

For the first 24–48 hours, the graft initially derives oxygen and nutrients from the underlying bed by diffusion (plasmatic diffusion or imbibition). The graft can increase in weight by up to 40%. During imbibition, the graft and the wound bed are held together via a layer of fibrin. The fibrin is eventually replaced by granulation tissue [2, 3, 8].

The second phase, inosculation, is defined by an anastomosis of the preexistent vessels of the graft and the wound base. This phase occurs during the second and third postoperative days [3].

For graft-take tooccur, the recipient site must be capableof producing capillary buds. Since capillaryoutgrowth is needed both to producegranulation tissue and to nourish askin graft, areas that granulate well (muscle and deep fascia), acceptgrafts readily. Other surfaces, such astendon denuded of its fascia covering, exposed bone, or cartilage, are incapableof producing granulation tissue and, therefore, are unable to nourish a skingraft [9].

Also the skingraft must remain in close approximationto the recipient bed during thephase of capillary ingrowth. The presenceof air, serum, or fluid between thegraft and recipient bed creates a barrierthrough which the capillaries cannotgrow fast enough to prevent necrosis ofthe graft [9].

Revascularization involves the growth, proliferation, and connection of vessels from the recipient base and sidewalls. The rate of revascularization is dependent on the thickness of the graft and the vascularity of the recipient bed. As a general rule, the thinner theskin graft, the faster it establishes a blood supply [9].

Within 4 to 7 days, full circulation has been restored to the graft. Restoration of lymphatic circulation also occurs within 7 days. Reinnervation of the graft begins approximately 2 to 4 weeks after grafting; however, full sensation may require several months or even years to return to normal [8].

#### **5. Technique**

#### **5.1 Split-thickness skin grafts (STSG)**

STSG are indicated for large defects (>5 cm), slow- or nonhealing chronic wounds, or as a temporary cover when monitoring a wound bed for potential cancer recurrence [3, 10].

This type of skin graft is useful when the definitive reconstruction of a wound is delayed, either for surveillance of an aggressive cancer or when granulation tissue is needed on the bed of the recepient site.

Donor site selection is based on the size of the graft needed to cover the wound, the patient's ability to care for the donor site and how the donor site wound would affect the patient's daily activities (walk, sit, sleep). Taking all this in consideration the medial and lateral thighs are most used for donor site. Also it is practical to consider donor sites that can be hiddenunder clothing, such as the medial or lateral upper arm, abdomen, back andbuttocks. Donorsites that offer large flat surfaces also facilitate theharvesting of STSGs [11].

Once the donor area has been selected, it should be shaved of all hair to aid in the harvesting and handling of the skin graft [8].

The donor site should be prepared and draped in the normal sterile fashion and local anesthesia may be infiltrated [4]. If the graft requirement is significant, saline may be infiltrated instead of local anesthesia to make the graft harvesting easier.

STSG may be harvested using a dermatome or the freehand technique, depending on the size of graft needed and location of the recipient site [3].

There are many electric dermatomes available (e.g. Davol, Padgett, Zimmer), all of them with adjustable graft width and thickness.

After marking the dimensions of the graft (mark the skin graft 15–20% larger than needed and thus allow for shrinkage), the skin is lubricated with sterile ointment. The assistant surgeon should keep the skin flat and stretched by countertension [12].

The dermatome is held at a 30° to 45° angle, and advanced, from proximal to distal, while traction is maintained on the skin. Toothless forceps are used to prevent the graft from getting snared, and the dermatome is lifted away while still engaged [10–12].

After the STSG is obtained it is transferred to a sterile-saline soaked gauze to keep it moist. Attention must be paid in order not to confuse the dermal and epidermal surface when handling the skin graft. A useful tip is to remember that the dermal surface glistens more than the epidermal side and also the edges of the graft will curve to the dermal surface.

Meshing the STSG allows the graft to cover a wound that is larger in dimensions than the unmeshed STSG. Meshing increases the coverage area by 25–35% and also increases the flexibility of the graft so it can be used over mobile surfaces such as joints [4].

It also provides fenestrations in the skin graft that allow the egress of fluid from the wound bed, which minimizes the chance of seroma or hematoma formation and subsequent graft failure. Mechanical meshing of grafts is recommended when they are being used to cover defects >8 cm in diameter or when extensive serosanguineous drainage is anticipated [4].

Meshing can be accomplished in a variety of ways, but the most common and efficient method is to use a hand-powered mechanical mesher to produce multiple uniform slits in a skin graft, approximately 0.05 inches apart. The skin to be meshed is placed on a carrier with the dermis side up and spread over the carrier. The graft is then passed through the mesher. It is is then covered with moist saline gauze. Split thickness grafts can be meshed to obtain expansion from 1:1 upto 1:4. In case of paucity of donor site and large recipient area the graft can be meshed to achieve expansion of 1:9. The survival of such widely meshed graft can be improved by covering it with 1: 3 meshed allograft. This methodis called sandwich grafting. Xenograft can also be used for this purpose. The disadvantages of meshing include suboptimal cosmesis and delay in ultimate closure of the grafted site [2, 8].

The donor site should be temporarily covered with gauze soaked in 1% lidocaine with epinephrine while attention is quickly turned back to the graft. The epinephrine in the solution promotes hemostasis in this acute, abrasion-like donor site [4].

The recipient site must be prepared before the placement of the STSG. Since there must be close contact between the skin graft and wound bed, a good hemostasis should be done in order to prevent hematoma formation. If the wound bed has granulated tissue all the fibrinous debris have to be removed.

When the STSG is placed over the recipient site sometimes it needs to be cut to fit the size of the wound. After the graft is trimmed it has to be attached to initiate contact between the graft and the wound bed. In order to achieve this a tie-over dressing is used. First apply an antibiotic impregnated gauze on the graft, after a foam dressing or sponge is putover the gauze, put single sutures around the defect and leave long tails of the sutures, this long tails will be tied over the dressing or sponge.

Attention is subsequently turned to the donor site, which is best treated as a superficial abrasion. Further hemostasis is usually not necessary. A moist occlusive dressing is applied, making use of antibiotic ointment or petrolatum and a nonadherent dressing such aspolymer film [4].

The donor site presents important drainage during the first 48 hrs, this is a normal process and it is important to inform the patient. In order to avoid fluid colection the dressing can be punctured at the site to allow drainage or the dressing can be changed more frequently.

In the postoperative period the most important part is to minimize all physical activity. Since any abrupt or strong movement may affect the graft, shearing forces can be created and the graft itself may be damaged or bleeding from the wound bed can occur. Separation of the graft from the recipient site compromises its vascularization and eventually its survival. This is why the patient is adviced to elevate the intervened area and restrict all physical efforts.

The manipulation of the dressings should be kept at minimum in order to avoid contamination or involuntary movement that may disrupt the process of revascularization of the graft, which takes about 3 to 5 days.

After wound healing is achieved it is important to advice the patient to avoid sunshine and to use sun-blocking agents to prevent hyperpigmentation, use a greasy ointment to reduce dryness and itching [12].

The advantages of using this type of skin graft are: Very easy and fast harvesting, provides good color match in most cases, they may be obtained from any area of the body, provides skin for large defects [12].

The disadvantages of this type of grafts are: Graft contraction and hyperpigmentation (Split thickness grafts will contract 10–20% immediately after harvest and up to 20–50% over time), fixation may be inadequate, leading to shearing and wound dehiscence, cannot be used on exposed tendon, nerves, cartilage, or bone, development of hematoma or seroma may lead to poor vascularization of the graft, in case of wound infection, skin graft may turn necrotic within 24 h [2, 12].

#### **5.2 Full-thickness skin grafts (FTSG)**

FTSG are very useful in dermatologic surgery, especially after the removalof a skin cancer, areas that are conducive to FTSG include nasal ala and tip, helix, medial canthus, lower eyelid, digits, and extremities. FTSG should be limited to less than 5 cm [3].

In order to maximize cosmesis, various factors must be taken into account when choosing a site to harvest, including photodamage, color, existing adnexal structures (hair), and the appearance of the donor site scar. Donor skin should be devoid of malignant lesions or any changes that might later be confused for recurrence of malignancy. Commonly used sites for FTSG are: pre- and postauricular regions, creases of the upper eyelids, nasolabial folds, supraclavicular region, lateral neck, antecubital fossa, and groin [3, 8].

Once the appropriate donor site has been chosen, anesthetized, cleansed, and prepared for harvest, a template of the defect is made by using gauze, cardboard labels, or foil from suture packaging. The template is then transposed to the donorsite.

The skin graft will contract at the recepient site, for this reason it is important to make the template 10–20% bigger in order to avoid distortion of the anatomy of the area that was intervened. When eyelids defects are closed using a skin graft the template needs to be oversized more so that ectoprion will not develop.

Full thickness grafts should be harvested at the level just deep to the dermis, not down to fascia, as the graft will need to be thinned [2]. Once the graft is obtained, all the subcutaneous tissue must be removed using curved iris scissors. Remove the adherent fat by putting the graft under tension. Roll the graft overyour forefinger and pull it down with your middle finger and thumb [12]. The goal is to expose the dermis. Since any remaining fat will obstruct the imbibition phase.

Remoistening the graft periodically with sterile saline or local anesthetic during the defatting procedure is recommended to prevent desiccation [11].

Before placing a skin graft, the recipient site must be clean and not actively bleeding [8].

After placing the graft in the recepient site it needs to be fixated with sutures. Optimal suturing technique is with the needle entering the graft first, 2–3 mm from the edge, and then exiting in the adjacent recipient site skin and subsequently tied with 3–4 throws of a square knot. Distance between sutures is usually 3–4 mm [4] (**Figures 1** and **2**).

It is important to place sutures sufficiently deep such that both the papillary and reticular dermis of the graft and recipient site are directly aligned with each other. Suturing that is too superficial apposes only the papillary dermis, leaving a dead space in the deeper reticular dermis which tends to retract more than the superficial papillary dermis. This increases the risk of both hematoma formation and a depressed, more visible scar. Excessively superficial suturing has also been implicated as a potential etiology of graft pin-cushioning [4].

#### *Types of Skin Grafts DOI: http://dx.doi.org/10.5772/intechopen.100857*

Bolsters are used to stabilize and protect the graft and to provide a uniform pressure dressing to the grafted area. Bolster materials include saline-soaked dental rolls, saline-soaked gauze, and mineral oil–soaked cotton balls. The bolsters should have a nonstick surface and should be fitted to the size of the graft. They are secured with simple interrupted sutures using 4–0 silk are placed in pairs directly across from one another 2–3 mm from the graft margins. Bolsters are left in place for 5 to 7 days [3, 10].

The donor site is repaired later after the graft has been placed as it is important to allow nutrient diffusion to the graft to begin [3].

During the postoperative period the use of antibiotic oinment is recommended for the recipient and donor site in order to avoid infection. Also the dressing in the recipient site has to be checked every day for one week and every 2 to 3 days at the donor site. Both areas have to be cleaned with saline solution. The sutures can be removed after 7–8 days.

Development of pink color during 3 to 7 days signals neovascularization and successful graft take. Over the ensuing 1 to 2 months, pink color diminishes, but the graft may remain lighter than surroundingskin (**Figures 3** and **4**) [10].

The advantages of this technique are: easy and rapid harvesting, provides excellent color match and adequate thickness of the skin, a small scar remains after skin harvesting and primary closure of the donor site [12].

The disadvantages of this type of grafts are: limited size of skin for harvesting, donor site will require STSG when primary closure is not possible [12].

**Figure 1.** *Initial attachment of the Full-skin graft.*

**Figure 2.** *Complete placement of sutures attaching the FSG.*

**Figure 3.** *Full-skin graft appearance after removing the bolster (48 hrs),*

**Figure 4.** *Full-skin graft appearance at one month after the surgery.*

#### **5.3 Composite grafts**

This type of graft consists of two different type of tissues. Mostly cartilage with or without subcutaneous tissue and the overlying skin. Because they offer support and structure composite grafts are used to repair full-thickness defects of the nasal ala and helical rim. The size of the defect for this type of graft is 1 cm or less.

They can also beused to fill partial-thickness defects that extend toodeeply for a full-thickness skin graft to heal withoutleaving a concavity or contraction of the free margin [13].

The metabolic needs of composite grafts differ from the needs of skin grafts, the former have greater demands and needs rapid revascularization in order to survive. The blood flow formed by the anastomoses between the wound bed and composite graft can extend only to a small portion beyond the margin of the graft. Portions of the graft that are beyond 1 cm from the vessel anastomoses is at risk of not receiving appropiate blood flow and is at risk of necrosis.

Its survival depends on passivediffusion of oxygen and nutrients through theperichondrium from adjacent vascularized tissue. The vascularity of the recipient bed is also aconsideration. The nasal ala is generally well suppliedwith blood vessels and can usually support composite grafts [13].

Because the cartilage in these grafts carries with itthe skin that will cover the cutaneous portion of thedefect, the donor site should be chosen so that thetexture, color, and nature of appendages match as best aspossible the features of the recipient site [13].

The ear exhibits a wide range of thicknesses, curvatures, and appendage-type structures [13]. Composite auricular graftsharvested from the helical crus are particularlyuseful, because they provide thin skin that istightly adherent to the underlying cartilage. Thegraft affords structural support and resemblesfine nasal skin being reconstructed [10].

First, the recipient site is measured andthe donor site marked such that the composite graftwill be approximately 5–10% larger than thedefect. This oversizing will compensatefor the natural shrinkage of the graft that occurs during healing [13].

Once the donor site has been closed, the graft isprepared. Using a pair of curved iris scissors, the skinis trimmed from the wings to expose the underlyingcartilage. The remaining cartilaginous pegs shouldframe the lateral aspects of the graft [13]. A hemostat or scissors maybe used to undermine pockets on each side of the defect. These pockets should run parallel to the alar or helicalrim and should only be deep enough to accommodatethe cartilaginous pegs of the composite graft. And the cartilaginouspegs are gently inserted into these pocketsso that the graft interlocks with its recipient bed [13].

The graft is securedin place with a single layer of suture throughskin and perichondrium, minimizing sutures passing through cartilage. Limiting sutures andgraft trauma facilitates robust vessel ingrowth [10].

Antibiotic-impregnated gauze should be placed inthe patient's nostril to stabilize the alar rim. Apressure dressing or bolster should be used to stabilize the graft [13].

In the postoperative perdiod, the intranasal gauze needs to stay for 24-48 hrs and then removed so that the wound can be cleaned. Any activity that may elevate the patient's blood pressure has to be avoided. The sutures can be removed after 7 days.

Composite grafts change their color during the following days after the procedure. At first the graft will be pallid because of tha lack of blood flow. After 6 hrs it changes color to lightly pink, representing the begining of the vessel anastomoses. The next 24–48 hrs the graft becomes blue because of venous congestion that follows, and will remain like this for a week, until venous drainage begins. Later it will become pink and this indicates adequate blood flow and graft survival. The pink color will increase in the next days reaching a red color as the healing process continues. After 2 to 6 months later the red color will disappear. The final tone can be achieved after 1 or 2 years.

#### **6. Complications**

All types of grafts can present complications that may compromise it's survival.

Complete or partial graft failure is the primary complicationseen with FTSGs. Causes for failure includehematoma, graft-bed contact disruption, infection, smoking, and excessive electrocoagulation of the wound base [8].

If the skin graft develops necrosis it should not be debrided, the necrotic tissue serves as a natural dressing that allows new skin formation under it. There can be some contour alterations made by the healing process, specially on the nose (elevation), that can improve by themselves in a period of 6 months, if after that period the alterations remain dermabrasion or intralesional steroids can be used.

The acute complications of STSG are the same of those presented by FTSG (hematoma, seroma, graft movement). Long term complications of STSG are related to skin graft contraction that may distort free margins, impair function, develop graft fragility or alter the final aesthethic result.

If infection of the graft is suspected or developed a skin culture needs to be performed and proper antibiotics should be given.

#### *Types of Skin Grafts DOI: http://dx.doi.org/10.5772/intechopen.100857*

In composite grafts short-term potential complications, includebleeding, infection, and necrosis of the graft. This last complication presents initially as a yellowish whiteness that remains and then is followed by the aparition of a black eschar.

Should the graft become necrotic, the escharshould not be debrided. The necrosis may only besuperficial, with the underlying dermis and cartilage still viable [13].

Long term complications of composite grafts are consequence of an inappropiate anchorage of the graft to the recipient site, trauma or extreme contractural forces, all of which can cause displacement or deformation of the graft.

#### **7. Conclusions**

Since their initial use almost 3.000 years ago skin grafts have been a very useful option for wound repair. Whether it is due to an ulcer, burn or surgery, wound closure can be accomplished via skin grafts in any of their modalities. Skin grafts offer a very useful alternative for reconstruction that can be applied to almost any site of the body. It is imperative to select an adequate donor site to offer the best match possible. The process and technique of each type of graft is easy to perfom. And with the correct sterile and surgical technique the possibilty of complications is minimized. This type of wound management should not be considered as a last resort, since their advantages outweigh the disadvantages.

#### **Author details**

Verónica Olvera-Cortés Instituto Mexicano del Seguro Social, Ciudad de México, Mexico

\*Address all correspondence to: dra.veronica.olvera@gmail.com

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Blatière V. Injertos cutáneos: injertos de piel de grosor variable y total. EMC Dermatología. 2021;55(1):1-17.

[2] Jensen AR, Klein MB, Ver Halen JP, Wright AS, Horvath KD. Skin Flaps and Grafts: A Primer for the National Technical Skills Curriculum Advanced Tissue-Handling Module. J Surg Educ. 2008;65(3):191-199.

[3] Leal-Khouri SM and Grummer SE. Skin Grafting. In: Nouri K. Mohs Micrographic Surgery. 1st ed. Springer-Verlag London. 2012. p. 433-442.

[4] Acosta AE, Aasi SZ, MacNeal RJ, Messingham MJ, Arpey CJ. Skin Grafting. In: Robinson JK, Hanke CW, Siegel DM, Fratila A. Surgery of the Skin: Procedural Dermatology. 3rd ed. Saunders Publishing. 2015. p.306-323.

[5] Hierner R, Degreef H, Vranckx JJ, Garmyn M, Massagé P, Van Brussel M. Skin grafting and wound healing—the "dermato-plastic team approach". Clin Dermatol. 2005;23:343-352.

[6] Losquadro WD. Anatomy of the Skin and the Pathogenesis of Nonmelanoma Skin Cancer. Facial Plast Surg Clin N Am. 2017;25:283-289.

[7] Ablove RH, Howell RM. The Physiology And Technique Of Skin Grafting. Hand Clin. 1997;13(2):163-173.

[8] Adams DC, Ramsey ML. Grafts in Dermatologic Surgery: Review and Update on Full- and Split-Thickness Skin Grafts, Free Cartilage Grafts, and Composite Grafts. Dermatol Surg. 2005;31:1055-1067.

[9] Lyons RJ. Promoting healing of skin flaps and grafts. AORN Journal. 1982:35(6):1174-1176.

[10] Brenner MJ, Moyer JS. Skin and Composite Grafting Techniques in

Facial Reconstruction for Skin Cancer. Facial Plast Surg Clin N Am. 2017;25: 347-363.

[11] Zhang AY, Meine JG. Flaps and Grafts Reconstruction. Dermatol Clin. 2011;29:217-230.

[12] Erovic BM, Lercher P. Skin Graft Harvesting. In: Erovic BM, Lercher P. Manual of Head and Neck Reconstruction Using Regional and Free Flaps. 1st ed. Springer-Verlag Wien. 2015. p. 53-60.

[13] Adams C, Ratner D. Composite and free cartilage grafting. Dermatol Clin. 2005;23:129-140.

### **Chapter 5**

## Skin Graft Fixation and Methods

*Sundaram Ravanasamudram Rajaram and Gauthami Sundar*

#### **Abstract**

Skin graft fixation constitutes the most important element for the success of the reconstruction. The stability of the skin graft over the wound is a determinant factor for its survival. Many techniques have been described in the literature for fixing the skin graft. The most frequent of the techniques is the tie over technique. Staples, fibrin glue are other advancements in the arena of skin graft fixation. The skin graft is covered by a dressing material which keeps it undisturbed and protects the graft from infection. The quest for an ideal dressing material has led to many innovative materials and methods to apply them.

**Keywords:** history of graft fixation, skin graft fixation, tie over dressing, staples, fibrin glue

#### **1. Introduction**

Skin grafting is one of the most commonly done surgical procedures as a part of reconstructive process. The skin grafts are routinely being used in a variety of situations including traumatic wound reconstruction, oncologic reconstruction, cosmetic problems like scar contraction. Skin graft fixation forms a crucial step in the success of the skin grafting. Various techniques of skin graft fixation have been practiced and they have their own advantages and disadvantages.

However, the basic principles of the skin graft fixation remains constant and when satisfied leads to the success of the procedure. Varying situations demand varying type of the skin graft fixation techniques.

The conventional skin graft fixation technique involves pressure application over the skin graft using a bolus and tie over sutures. The skin graft edges are fixed to the recipient bed meticulously using sutures that would be removed later. Over the years, further advancements in graft fixation techniques have been witnessed like the use of staples replacing the sutures, glue for skin graft adhesion and Negative wound therapy. This chapter elaborates the various skin graft fixation techniques and the dressing materials which aid in skin graft healing.

#### **2. History of skin graft fixation techniques**

The history of free skin grafting dates back to as early as 600 BC in ancient India where the defects of the ears, nose and lips were treated using free gluteal grafts and skin grafts [1].

Tile maker caste have been known for practicing free skin grafts, harvested from the gluteal region which was prepared by beating with wooden slippers until significant swelling had taken place they also used a secret cement for adhesion of the skin grafts which was called the "ancient Indian method" [2].

The suturing of the skin edges had been carried out by using giant ants, according to Sushrutha Samhitha. The ants were gently allowed to bite across the skin edges to be approximated. As soon as the ant bites well, the body is cut off leaving the head of the ants in place. There are evidences of using thorns to approximate the skin edges too. Similar technique for skin approximation using the ants had been in practice in ancient Egypt also.

It was the 'cisterian monks' in Worcesterschire who made a mark in the history for having used needles and sutures to approximate the wound edges. Evidently after this time scale, the modern day suturing started and securing the skin grafts by sutures come into practice [3].

Bergel in 1909 discussed about the hemostatic nature of fibrin. In 1985, Rose, Dresdale et al. [4] described the combination of fresh frozen plasma and bovine thrombin to form fibrin glue. During the 1990s, the fibrin sealant was widely put into use and became FDA approved. The fibrin also showed adhesive properties that were utilized in cases of fistula closure and seroma prevention. Later it was used as a skin graft fixation agent sometimes replacing sutures and staples [5].

Present day scenario sees the use of sutures, staples and fibrin glues for fixation of the skin grafts.

#### **3. Fixation of skin grafts**

The recipient bed interface has a thin fibrin bed that holds the skin graft on to it. The fibrin acts as a barrier against infections that can cause graft failure [6]. Bleeding, shearing force, wound infection can all lead to graft loss, thus necessitating proper anchoring and protective dressing.

The skin graft goes through 2 distinct phases of adherence.

Phase 1: it lasts till 72 hours. The adherence is maintained by fibrin layer.

Phase 2: it commences after 72 hours because of the fibrous ingrowth and vascular anastomoses [7].

#### **3.1 Securing the skin grafts**

The skin graft edges are trimmed and the recipient wound edges are undermined to accommodate the skin graft (**Figure 1a**–**e**). The edges of the skin graft are approximated and secured to the edges of the recipient wound with sutures or staples (**Figure 2a** and **b**). The staples have the added advantage of consuming less time in securing the skin graft edges. There are several operators who wish to place absorbable sutures thereby negating the burden of suture removal after healing [8].

#### **3.2 Dressing over the skin graft**

Appropriate dressing is placed over the skin graft for better adaptation and graft healing. This also avoids the seroma formation and hematoma formation that can subsequently lead to infection and graft failure.

#### *3.2.1 Tie over dressing/bolster dressing*

The tie over dressing is one of the earliest and effective methods for graft fixation (**Figure 3a** and **b**). Once the graft is transferred to the recipient bed and secured with sutures, a bolster is placed on the skin graft and secured with silk sutures running over the bolster and offering some pressure that prevents dislodgement. The bolster generally would be a piled up gauze pieces.

*Skin Graft Fixation and Methods DOI: http://dx.doi.org/10.5772/intechopen.100377*

$$\mathbf{b}$$

#### **Figure 1.**

*(a) A case of facial scar. (b) Undermining of wound edges. (c) Skin graft edges trimmed. (d) Skin graft adapted. (e) Skin graft secured with sutures.*

Although supported only by some observational studies, the tie over dressing remains simple and effective means for skin graft fixation.

#### **Figure 2.** *(a) A case of burns scar. (b) Skin graft secured with staples.*

#### **Figure 3.**

*(a) A case of melanocytic naevus. (b) Initial healing of Skin graft after bolster removal.*

Tie over dressing involves downward pressure on the skin graft surface thereby adapting the skin graft well onto the recipient area thus eliminating the hematoma and seroma formation leading to good take of the skin graft. The principle of tie over dressing remains as simple as that.

Such a simple technique also is accountable for flipside issues inviting criticism. The downward pressure when it exceeds the capillary pressure, can cause graft damage. Prolonged intraoperative time and graft healing time, technique sensitive procedure, may hinder inspection and wound care in the postoperative period are other disadvantages. Also, no Randomized Control trials exist to prove the superiority of tie over technique over non tie over techniques [9].

#### *3.2.2 Negative wound therapy*

Negative wound therapy consists of application of gauze packs over the skin graft which is sealed by sticking an adhesive dressing. The dressing consists of

#### *Skin Graft Fixation and Methods DOI: http://dx.doi.org/10.5772/intechopen.100377*

a small fenestration that is connected to the vaccum regulator with the pressure maintained at 125 mm Hg.

Mohsin et al. concluded from their study that negative wound therapy has the following advantages.


#### *3.2.3 Non pressure dressings*

Netscher and associates advocate moist non adherent gauze applied over the grafted site and is secured with self-adhering foam. Application and removal of the dressings are technically easy and it offers an even pressure over the grafted area [11].

Saltz and Bowles also advocate using Reston foam applied over Xenoform gauze as graft dressings [12]. Minami and colleagues acknowledge the usefulness of polyurethane dressings over the skin grafts as such dressings avoid the risks of pressure necrosis that is seen in tie over dressings [13].

Balakrishnan advocates the use of Lyofoam, which is applied over the graft directly. It is an inert, bacteriostatic, semipermeable polyurethane foam that enhances reepithelialization. Its inner surface is smooth and hydrophilic and outer surface is hydrophobic. Lyofoam is directly applied over the skin grafts and secured with staples [14].

#### *3.2.4 Fibrin glue/octyl-2-cyanoacrylate ("super glue")*

Fibrin sealant, two component material composed of fibrin and thrombin has been widely used as an adhesive for the skin graft ever since it got FDA approved. When applied at the skin edges it exhibits a remarkable adhesion property [15].

It has been advocated for its property of improving graft survival, reducing blood loss, hastening healing over large surface and thereby produces better results. A thin layer of fibrin glue significantly improves the graft take especially in mobile parts of the body [16].

#### *3.2.5 Quilting*

Quilting involves placing basing sutures on the surface of the graft thereby adapting it well to the recipient bed. Such quilting sutures are generally placed using absorbable ones. They are aimed at reducing the dead space in the graft that can lead to seroma formation.

In a study conducted by Yuhui Wu, the quilting sutures have been documented to reduce grade 2 and 3 seroma thereby improving the healing [17].

Other dressing materials are listed in the **Table 1.**

#### *3.2.6 Tie over dressing vs. non tie over technique*

Akhavani et al. and Dhillon et al. compared both these techniques to find out there is no statistically significant difference in graft take rate and infections. Even a study conducted by Yuki et al. in 266 patients also concluded the same [32–34].


#### **Table 1.**

*Other dressing materials documented.*

In our experience, the application of pressure over the skin graft becomes an optional entity and is sometimes dictated only by the anatomical area to be grafted. Any anatomical area that displays frequent movement that self-endangers the viability of the skin graft needs a Tie over dressing. Also an anatomical area where dead space creates the risk of seroma or hematoma collection compromising the adaptation of skin graft requires a tie over dressing for better adaptation. This again confirms the evidences that draw inconclusive evidences about the best type of skin graft fixation techniques.

In certain cases, absorbable sutures are preferred over the silk sutures as the silk gets buried while the bolster is removed when the healing is complete. Although our experience with cyanoacrylate glue is limited, the idea of applying any material other than autogenous entities had always raised concerns for the fear of it instilling hypersensitivity reactions.

#### **3.3 Challenging anatomical areas for skin graft fixation**

The advances in the ablative surgical techniques have only left with more complexities for the reconstruction procedures. The necessity and the radical nature of oncologic resections carried out in the head and neck areas demand meticulous reconstructive measures that make them challenging [35].

#### *3.3.1 Reconstruction of the sinus cavities*

Post resection, the skin graft is secured with sutures in the sinus lining and available cancellous bone surfaces. The sinus is stuffed with petrolatum gauze that would offer even pressure over the skin graft surface. One of the ends of the gauze is seen jetting out through orifices created intraorally or at the face near the floor of the orbit. After the healing, the gauze is gently removed out through the orifices. The remaining orifice defects are addressed prosthetically.

#### *3.3.2 Reconstruction of alveolus*

The alveolar bone is trimmed to make the cancellous bone exposed. The skin graft margins are adapted perfectly over the cancellous bone surface and adjacent soft tissue. Sutures are placed if possible. Acrylic stent dressing is placed over the gauze dressing.

In mandible, the acrylic is secured in situ by circum mandibular wiring. In maxilla, the acrylic stent is secured by peralveolar wiring or lateral suspension wiring.

#### *3.3.3 Reconstruction of floor of mouth*

The skin graft adaptation and securing is carried out by help of sutures. The gauze foam dressing that is applied over the graft is secured with suture ties that run to the supra hyoid region where it is anchored.

#### *3.3.4 Reconstruction of palate*

Palatal skin graft fixation requires construction of a Hawley's appliance with a palatal extension that would fill in the defect. This acrylic stent is fabricated preoperatively and is applied over the palatal skin graft (**Figure 4a** and **b**).

#### *3.3.5 Reconstruction of tongue*

The tongue is an extremely mobile organ where the skin graft fixation becomes very difficult. The grafted site is covered with foam dressing. The tongue is then compressed into the floor of the mouth by the fixation of a plate lined with foamrubber sponge. The plate in turn is anchored to the teeth using wires or with circummandibular wiring if edentulous.

Tongue physiotherapy is carried out post healing to prevent fibrosis.

#### *3.3.6 Reconstruction of larynx*

After the appropriate portions of the laryngeal structures have been excised, inclusive of the homolateral laryngeal tissues and frequently passes beyond the anterior commissure or posterior commissure to the opposite cord, the graft is fitted

**Figure 4.** *(a) Model with diagrammatic presentation of extent of the defect. (b) Acrylic stent.*

to the outside of a modeled tantalum wire-mesh or plastic framework and carefully sutured into position. The position is maintained by a stent that avoids stenosis due to contraction.

#### **4. Conclusion**

In conclusion, the skin graft techniques and dressings are few in number for consideration and have their own indications, merits and demerits. Functionally all the fixation techniques when done well and proper serve the healing of the graft well. No technique rules over the other with better benefits. Evidence of comparison of the fixation techniques also prove the same till date. Future is foreseen to develop newer techniques for graft fixation and dressings and more evidence based comparison for arriving at better conclusions.

#### **Acknowledgements**

Dr.Manjunath N.M. MDS, M Phil,FAM, FAOCMF Consultant Oral and Maxillofacial Surgeon, Director of Dew Dental and maxillofacial Center, Bangalore, Karnataka. Dr.Venkatasubramanian MCh Plastic Surgery, pudhukottai, Tamil nadu. Dr.Murali Manivannan, MCh.,MRCS (Edin), DNB, Consultant Vascular Surgeon, Thanjavur Medical college and Hospital, Thanjavur, Tamil nadu.

#### **Conflict of interest**

The authors declare no conflict of interest.

#### **Notes/thanks/other declarations**

I extend my sincere thanks and gratitude to Dr. Gauthami Sundar and Dr. Rajaram for the Literature support. My deep sense of gratitude to Dr. Murali Manivannan for the timely contributions for the chapter.

*Skin Graft Fixation and Methods DOI: http://dx.doi.org/10.5772/intechopen.100377*

#### **Author details**

Sundaram Ravanasamudram Rajaram1 \* and Gauthami Sundar2

1 University of Science and Technology, Fujairah, United Arab Emirates

2 Dr.Rajaram's Dental Surgery, Thanjavur, India

\*Address all correspondence to: sundarum88@gmail.com

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

#### **References**

[1] Chick LR. Brief history and biology of skin grafting. Ann Plast Surg 1988;21:358-365.

[2] Davis JS. Address of the President: The Story of Plastic Surgery. Ann Surg 1941;113:641-656.

[3] HaywardL. Surgicalneedles, ancient and modern.Transactions of the Institute of British Surgical Technicians1961;1:18.4 Druitt R. The Surgeon's Vademecum, 8th edition.

[4] Dresdale A, Rose EA, Jeevanandam V, Reemtsma K, Bowman FO, Malm JR. Preparation of fibrin glue from single-donor freshfrozen plasma. Surgery. 1985 Jun; 97 (6):750-755. PMID: 3873716.

[5] Bergel S (1909) Uber wirkungen des fibrins. Dtsch Med Wochenschr 35:633

[6] Burleson R, Eiseman B: Nature of the bond between partial-thickness skin and wound granulations. Am Surg 177:181, 1973. 84.

[7] Tavis MJ, Thornton JW, Harney JH, et al: Graft adherence to de-epithelialized surfaces: a comparative study. Ann Surg 184:594, 1976

[8] Han HH, Jun D, Moon SH, Kang IS, Kim MC. Fixation of split-thickness skin graft using fast-clotting fibrin glue containing undiluted highconcentration thrombin or sutures: a comparison study. Springerplus. 2016;5(1):1902

[9] Kromka W, Cameron M, Fathi R. Tie-over bolster dressings vs basting sutures for the closure of full-thickness skin grafts: A review of the literature. J Cutan Med Surg. 2018;22:602-606.

[10] Mohsin M, Zargar HR, Wani AH, Zaroo MI, Baba PUF, Bashir SA, Rasool A, Bijli AH. Role of customised negative-pressure wound therapy in the integration of split-thickness skin grafts: A randomised control study. Indian J Plast Surg. 2017 Jan-Apr;50(1):43-49.

[11] Netscher DT, Marchi M, Wigoda P: A method for optimizing skin graft healing and outcome of wounds of the penile shaft and scrotum. Ann Plast Surg 31:447, 1993.

[12] Saltz R, Bowles BJ: Reston: an alternate method of skin graft fixation (letter). Plast Reconstr Surg 99:601, 1997

[13] Minami RT,Holderness H, Vistnes LM. A tie over dressing with polyurethane foam. Plast Reconstr Surg 1973;52:672

[14] Balakrishnan C: Dressing for skin grafts of the penis (letter). Plast Reconstr Surg 95:208, 1995

[15] William D. Spotnitz. Fibrin Sealant: Past, Present, and Future: A Brief Review. World J Surg (2010) 34:632-634 DOI 10.1007/s00268-009-0252-7

[16] Currie LJ, Sharpe JR, Martin R: The use of fibrin glue in skin grafts and tissue-engineered skin replacements: a review. Plast Reconstr Surg 108:1713, 2001.

[17] Wu, Y., Wang, S., Hai, J. *et al.* Quilting suture is better than conventional suture with drain in preventing seroma formation at pectoral area after mastectomy. BMC Surg 20, 65 (2020). https://doi.org/10.1186/ s12893-020-00725-8

[18] Johnson PA, Fleming K, Avery CME: Latex foam and staple fixation of skin grafts. Br J Oral Maxillofac Surg 36:141, 1998.

[19] Wolf Y, Kalish E, Badani E, et al: Rubber foam and staples: do they secure

#### *Skin Graft Fixation and Methods DOI: http://dx.doi.org/10.5772/intechopen.100377*

skin grafts? A model analysis and proposal of pressure enhancement techniques. Ann Plast Surg 40:149, 1998.

[20] Smoot EC: A rapid method for splinting skin grafts and securing wound dressings (letter). Plast Reconstr Surg 100:1622, 1997.

[21] Amir A, Sagi A, Fliss DM, Rosenberg L: A simple, rapid, reproducible tie-over dressing. Plast Reconstr Surg 98:1092, 1996.

[22] Cheng LC, Lim TC, Tan WTL: A simple tie-over dressing (letter). Plast Reconstr Surg 101:246, 1998.

[23] Vloemans AFPM, Kreis RW: Fixation of skin grafts with a new silicone rubber dressing (Mepitel). Scand J Plast Reconstr Surg 28:75, 1994.

[24] Sawada Y, Yotsuyanagi T, Ara M, Sone K: Experiences using silicone gel tie-over dressings following skin grafting. Burns 16:353, 1990.

[25] Renz BM, Stout M, Sherman R: Rubberband stents for skin grafts: how I do it. Am Surg 60:707, 1994.

[26] Ren J, Yiang OJ, Deng B, Yiang YN: Transparent gasbag tieover for persistent pressure and inspection in free skin grafting. Plast Reconstr Surg 95:396, 1995.

[27] Ward RS, Reddy R, Brockway C, et al: Uses of Coban selfadherent wrap in management of postburn hand grafts: case reports. J Burn Care Rehabil 15:364, 1994.

[28] Grabski WJ, Giandoni MB, Anderson LL: Surgical pearl: hydrocolloid dressings for full-thickness skin grafts. J Am Acad Dermatol 32:273, 1995.

[29] Watson SB, Miller JG: Optimizing skin graft take in children's hand burns—the use of Silastic foam dressings. Burns 19:519, 1993.

[30] Balakrishnan C: Simple method of applying pressure to skin grafts of neck with foam dressing and staples. J Burn Care Rehabil 15:432, 1994.

[31] Wells MD, Kirn DS: A new method of skin-graft stabilization: the Reston technique. Ann Plast Surg 34:554, 1995.

[32] Akhavani MA, McKinnell T, Kang NV. Quilting of full thickness grafts in the hand. J Plast Reconstr Aesthet Surg. 2010;63(9):1534-1537.

[33] Dhillon M, Carter CP, Morrison J, Hislop WS, Currie WJ. A comparison of skin graft success in the head & neck with and without the use of a pressure dressing. J Maxillofac Oral Surg. 2015;14(2):240-242.

[34] Yuki, A., Takenouchi, T., Takatsuka, S., Fujikawa, H. and Abe, R. (2017), Investigating the use of tie-over dressing after skin grafting. J Dermatol, 44: 1317-1319. https://doi.org/10.1111/ 1346-8138.13916

[35] John J. C. Free skin grafting in the sinus, Oral, and Pharyngeal areas in Radical surgery of the Head and Neck, Head and Neck Department of the Pack Medical Group and the Surgical Service OE St. Vincent's Hospital, New York, New York. Dec 5, 1953.

#### **Chapter 6**

## Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds

*Marcelo Fonseca, Aldo Cañete, Dino Ibaceta, Catalina Buchroithner, Florencia Disi and Juan Olivares*

#### **Abstract**

Cryopreserved total skin allografts are a new therapeutic alternative for the management of complex wounds. Their properties allow them to be classified as a temporary coverage for some patients and as definitive in others. And they can be an alternative option to the use of dermal regeneration templates.

**Keywords:** skin allograft, biological dressings, wound healing, skin substitutes, dermal regenerators

#### **1. Introduction**

Historically, choosing the therapeutic options for the management of complex wounds was based on the concept of the "reconstructive ladder", in which reconstructive methods were ranked by complexity and the simplest options capable of solving the problem had to be chosen. The latter has evolved over time, with the emergence of the "reconstructive elevator concept", where a surgeon can ascend directly to the appropriate level in order to obtain the best qualified reconstruction, and due to the need of incorporating new advances in wound healing management into the "reconstructive ladder" [1, 2].

The use of skin allografts (SA) for wound coverage began during the 19th century. Currently occupy a predominant place within the temporary coverage techniques, especially in burn patients, with little residual skin capital, and with extensive clinical experience in other pathologies [3–7]. SA provide a physiological lining to control the hydro electrolyte losses, reduce the pain and infection risk and improve local bed conditions by promoting angiogenesis and the maturation of the underlying granulation tissue [8, 9]. However, due to immunological processes, they are usually rejected after 10–12 days and may eventually be a vector for infectious diseases [10, 11].

Most of the SA come from cadaveric donor; are harvested as partial skin grafts (**Figure 1A**) with a dermatome and are preserved using glycerol at high concentrations, causing cellular death with the obtention of non-viable tissues [12, 13].

**Figure 1.** *A. Split-thickness skin graft B. Total skin allografts.*

#### **2. Cryopreserved total skin allografts**

#### **2.1 Background**

The low rate of human organ and tissue donation and the cultural and religious restrictions for the use of cadaveric tissues in certain countries, have opened the door to the pursuit of other sources of SA, particularly in patients who underwent body contouring surgeries (abdominoplasty, reductive mammoplasty), either for esthetic or reconstructive reasons. This allows the entire resected flap to be procured, allowing the obtention of total skin allografts (TSA) (**Figure 1B**) [ 14–17].

#### **2.2 Tissue production**

The process of obtaining TSA is initiated with the invitation of patients who are candidates for body contouring surgeries to participate in the donation of the redundant fatty skin flap, which would otherwise be a waste product. This represents the first difference with SA obtained from corpses, the TSA are obtained from living donors. Donors are submitted under a health survey (**Table 1**), the absence of exclusion criteria is verified (**Table 2**) and routine examinations for tissue donation are performed (**Table 3**). All the above is assessed to guarantee the microbiological safety of the tissues, which is mainly based on the selection of the donor, permitting the rejection of infections or any biological agent that could cause diseases in the recipient [18].

#### *Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds DOI: http://dx.doi.org/10.5772/intechopen.99125*



#### **Table 1.**

*Living tissue donor questionnaire.*

It is important to mention that patients submitted to bariatric surgery with a secondary weight loss, have cutaneous structure and histological changes. Including a lower fibroblast and elastin concentration and collagen fiber organization, sites of chronic inflammation, sebaceous glands infections and metalloproteinases levels similar to the skin of patients with cancer and burns. Therefore, it is expected that the quality of TSAs from this group of patients will be lower [19, 20]. After the donor selection, the process is divided into 10 stages: 1) surgical procedure/body contouring surgery, 2) procurement itself, 3) packaging and identification, 4) storage, 5) transport to the processing center, 6) processing, 7) cryopreservation/quarantine, 8) validation, release, records, 9) transfer and 10) clinical use. All of the above must be within the framework of an organ and tissue donation program that permits the generation and guarantee products of high: biological quality, sanitary safety and therapeutic value [21].

#### *2.2.1 Surgical procedure/body contouring surgery*

The skin processing is performed in the operating room, at the same time as the body contouring surgery, with all asepsis and antisepsis measures, under general anesthesia and by the same surgical team. After the redundant skin marking and the adipose skin flap dissection, the resection of the flap is performed. Subsequently, two teams are formed: one finishes the body contouring surgery and the other, on a separate surgical table, performs the skin procurement.

#### *2.2.2 Skin treatment*

The dissected adipose skin flap is placed on a separate operating table. Total skin procurement (including dermis) is performed, removing the fat from the deeper dermis with scissors (**Figure 2**). Tissue samples (3) are also taken for current (aerobic), anaerobic and fungal culture. The procured skin is placed in a sterile container with 500 cc of physiological saline solution with 1 g of Cloxacillin and 80 mg of Gentamicin, hermetically closed, making sure the skin is completely submerged. This process of the allograft obtention gives the second distinctive characteristic to the TSAs: they are total skin allografts.

#### *2.2.3 Packaging and skin identification*

The vials containing the skin are stored in double sterile bags of at least 90 microns. Each vial is hermetically sealed, removing as much air as possible, and labeled with the tissue code and the date and time of processing.

#### *2.2.4 Skin storage*

The skin is transferred from the operating room to a temporary storage place in a refrigeration unit, in order to maintain the temperature between 2 and 8°C.

#### Exclusion criteria:

	- Patients with history or carriers of HIV/AIDS.
	- Patients with a history of Hepatitis B or C.
	- Patients with a history of active Tuberculosis.
	- Patients diagnosed with Syphilis or positive VDRL.
	- Patients diagnosed with HTLV I and II.
	- Patients diagnosed with Chagas disease.
	- Patients with diagnosis of Rabies, Congenital Rubella and Malaria.
	- Degenerative diseases
		- a. Any type or manifestation of Dementia.
		- b. Alzheimer's disease.
		- c. Parkinson's disease.
		- d. Multiple sclerosis.
		- e. Creutzfeldt-Jakob disease.
	- Infectious diseases
		- a. Bacterial encephalitis.
		- b. Viral, fungal or parasitic meningitis.
		- c. Bacterial meningitis.
		- d. Progressive multifocal leukoencephalopathy.
		- e. Subacute sclerosing panencephalitis.
		- f. Active viral encephalitis or encephalitis of unknown cause.
	- g. Fungal or parasitic encephalitis.
	- History of neoplasia except for cervical uterine cancer in situ.
	- Lymphadenopathy for more than one month.
	- Lymphomas, lymphosarcomas
	- Leukemias.
	- Metastasis of primary or secondary malignant tumors (lung, breast, cervical, colon, prostate, squamous cell, melanomas, lymphomas, leukemias, central nervous system, among others).
	- Patients who have been treated with growth hormone.
	- Patients with Hemophilia.
	- Patients carriers of autoimmune diseases or Mesenchymopathies such as Rheumatoid Arthritis, Systemic Lupus Erythematosus.
	- Patients who have been treated with prolonged corticosteroid therapy.
	- Any suspicious skin alteration.
	- Unsafe sexual behavior.
	- Drug abuse (including intravenous, intramuscular and subcutaneous).
	- Commercial sex workers.
	- Inmates.
	- Individuals with tattoos, (or) body piercing performed in the last 6 months.
	- Individuals from whom no history of sexual behavior can be collected.
	- Skin contaminated by toxins.
	- Pyoderma.
	- Any skin lesion: infectious, traumatic or vascular.
	- Psoriasis.
	- Epidermolysis bullosa.
	- Loxocelism.
	- Structurally damaged skin (due to autoimmune or collagen diseases).

*HIV: human immunodeficiency virus; HTLV: human T-lymphotropic virus; AIDS: Acquired immunodeficiency syndrome; VDRL: Venereral Disease Research Laboratory.*

	- Standard culture (aerobic)
	- Anaerobic culture
	- Mycotic culture.

**Table 3.** *Laboratory tests.*

**Figure 2.** *Procurement of total skin with scissors from redundant adipose skin flap.*

#### *2.2.5 Skin transportation*

The skin is sent for processing, in our particular case, to the National Tissue Bank (NTB), always within 36 hours from harvesting, assuring the container maintains a temperature between 2 and 8°C.

#### *2.2.6 Processing*

The TSAs are prepared in the NBT as implants, following two stages: In the first one, the measurement of the flap is conducted, performing cuts in segments of

*HIV: human immunodeficiency virus; HTLV: human T-lymphotropic virus; VDRL: Venereral Disease Research Laboratory.*

#### *Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds DOI: http://dx.doi.org/10.5772/intechopen.99125*

different sizes according to the request; for example, in an average abdominoplasty, approximately 300 cm<sup>2</sup> of useful surface are obtained.

Subsequently, a revision of the shaving, washing cycles (to reduce the microbial load), obtention of sample number 2 for cultures (the first one was intraoperative) and immersion in cryopreservative solution for 1 hour are performed. In the second stage, the preparation, cutting, measurement, packaging and labeling of each obtained flap is conducted. Samples number 3 and 4 are taken for culture, which are performed during the packaging stage. Finally, a 5th sample is taken, also for culture, as a backup.

#### *2.2.7 Cryopreservation and quarantine*

Cryopreservation freezes the TSAs in the presence of a cryoprotectant (10% glycerol), which prevents the crystallization effects while maintaining viability over time after freezing. Viability being understood as the capacity of a biological unit to remain alive. The cryopreserved total skin allograft (CTSA) is kept frozen at 80°C awaiting the results of serial cultures until irradiation. The latter is performed with a dose of 25 to 28 kGy, in dry ice to maintain the cold chain, being a complementary procedure for tissue sterilization. The viability of the tissues obtained gives the third distinctive characteristic to CTSAs, which is fundamental for the clinical results [22, 23].

#### *2.2.8 Validation, release and records*

An adequate quality management system requires having a dossier or record of each tissue processed, which allows the evaluation of each of the steps from the generation to the implantation of the CTSAs in the recipient, permitting the monitorization and traceability. Once the donation, procurement and processing procedures have been reviewed and the microbiological results have been verified, the tissues are released for clinical use.

#### *2.2.9 Transportation*

Following the tissue release, they are transferred for clinical use on dry ice, maintaining the cold chain (80°C).

#### *2.2.10 Clinical use*

In the preoperative period, the size of the defect to be covered should be calculated in order to choose the CTSAs. The CTSAs should be washed 3 times with warm saline (no more than 40°C) to remove cryoprotectants. The wound bed is prepared by resection of necrotic, devitalized tissues and areas with granulation disorder. The CTSAs is fixed with stitches and/or brackets associated with negative pressure therapy [24].

#### **3. Clinic**

The CTSA has an initial attachment similar to an autologous skin graft, to later evolve towards rejection, at 21 days average, which is clinically evidenced by coloration change and the formation of a superficial necrotic eschar. When the latter is removed, it exposes vital tissue adhered to the host (**Figure 3**).

#### **Figure 3.**

*Diabetic patient, 68 years old, with flap necrosis after transmetarsal amputation. a. Coverage deficit with bone exposure associated with disordered granulatory tissue. b. Coverage with CTASs. c. Evolution CTASs after 28 days. d. Receiving bed after escharectomy of superficial part of CTASs. e. Partial skin autograft, result at day 7, which was subsequently lost in its entirety and managed with advanced healing. f. Result: 4 months after initial surgery.*

This is evidenced histologically in the CTSAs by necrosis foci with infiltration mainly of nuclear polymorphs (**Figure 4a**) and in the recipient bed by the presence of an interface rich in fibroblasts and neoformation vessels (**Figure 4b**).

This interface or neo-dermis is also visualized with imaging studies; in magnetic resonance imaging (MRI) CTSAs can be seen with a superficial non-catching component and a deep component that is enhanced by the contrast medium, similar to the vascularized dermis (**Figure 5**) [25]. For SA, it had already been described that some elements of the dermis, mainly fibroblasts, could be permanently integrated into the host, with exceptional situations of complete attachment and absence of rejection of the SA. The most mediatic case involved Sir Winston Churchill, who during the Nile War, donated skin and it was grafted to a wounded comrade and "remains there to this day and has lasted well in many ways. Myself, keep the scar as a souvenir." [26–28].

CTSAs maintain the entire donor dermis, which participates in the proliferation of a neo-dermis rich in fibroblasts and neoforming vessels, also acting as a scaffold and a biological inducer in the wound bed. CTSAs have been shown in xenograft models to promote angiogenesis and type 1 collagen production without eliciting a significant fibrotic response [29]. Rejection of the CTSAs should not be interpreted

#### **Figure 4.**

*a. Histology. Hematoxylin/eosin stain. CTSAs at the time of escharectomy (21 days). Circled are shows infiltration of nuclear polymorphs, necrosis areas. b. Post-CTSAs receptor bed. Black arrow: Fibroblasts, red arrow: Neoformation vessels.*

as a therapeutic failure, but as a stage of what we have called intermediate coverage. Since part of the CTSAs is lost and part adheres to the recipient bed, obtaining an interface of neodermis allows the completion of the definitive coverage with an autograft and a complete healing by second intention. This also produces a secondary contraction of the wound, reducing size of the defect.

The increased survival of seriously burnt patients with severe sequels, mainly due to the limited contribution of the autologous partial skin graft dermis and second intention scarring of the burnt skin, was the main motive for the dermal matrix development. Currently, available dermal substitutes (biologic, synthetic or biosynthetic origin) are fundamentally used as a scaffolding or biocompatible structural support, that is colonized by the patient's cells in order to form a neodermis, which is practically identic in structure as the receipt's dermis [30–34].

#### **Figure 5.**

*Magnetic resonance images of the foot in the sagittal plane enhanced in STIR -short tau inversion recovery- (a), T1 (b) and T1 with fat saturation and contrast medium (c), showing the graft with a superficial noncapturing component (white arrow) and a deep component that enhances with the contrast medium (yellow arrow) similar to the vascularized dermis. Between the latter and the bone tissue, there is low signal material with discrete enhancement (red arrow). (m2: Second metatarsal; m3: Third metatarsal).*

It is important to emphasize that dermal regeneration templates share various advantages with CTSAs, including: a) immediate wound closure, thus avoiding fluid loss and restoring the functional barrier of the skin, b) coverage of structures such as bone, cartilage and tendons and c) better scar quality and elasticity. But they differ mainly in the high cost of dermal regeneration templates, which is the main reason for their limited use in clinical practice, and the fact that they necessarily


*Years (Y), Months (M), Femenine (Fem), Masculine (Masc), CTSA: Cryopreserved total skin allograft. \* Patient undergoing two interventions with cryopreserved total skin allograft.*

#### **Table 4.** *Clinical experience. Summary.*

require a second time for skin autografting. Regarding the latter is that CTSAs can be used as an alternative to dermal regeneration templates [35, 36].

#### **4. Clinical experience**

Our clinical experience was initiated on August 1st, 2020 and persists to the date. Mainly following the pursuit of cutaneous coverages for seriously burnt patients, given the lack of dermal regeneration matrix since their high cost and limited availability. The latter is supported by the disposal of concomitant residual abdominal skin grafts following abdominoplasty surgeries. The donor sample was constituted by fourteen female patients, of 31 to 55 years with an average age of 40 years. The receipt sample was composed by 13 patients (two patients underwent two surgical procedures), ages ranging from 2 months to 83 years. With the following diagnosis: Diabetic foot (5), contained laparostomy (2) complex extremities wounds (3), relapsed scalp sarcoma (1) and melanoma (2) [37]. Clinical evolution is summarized in **Table 4**.

#### **Figure 6.**

*Female patient, 53 years old. With a history of dermatosarcoma of the scalp. With resection and subsequent reconstruction with local flaps and partial skin grafts. Tumour recurrence. a. Dermatosarcoma of the scalp. b. Defect of coverage post resection. c. Fenestration of the skull. d. CTSA 30 days. e. CTSA 60 days f. CTSA 150 days, completely healed wound by second intention.*

*Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds DOI: http://dx.doi.org/10.5772/intechopen.99125*

#### **Figure 7.**

*30-week preterm infant. The patient evolves with necrotizing enterocolitis, requiring intestinal transit defunctionalization and evisceration on two occasions. a. Laparotomy contained. b. Immediate postoperative CTSA on open abdomen. c. Postoperative 21 days. d. Postoperative 35 days. e. Postoperative 60 days, protrusion of paraostomal hernia associated with Valsalva is observed, however the CTSA area shows continent, in addition to smaller size. f. Postoperative 90 days with healing by second intention, without intra-abdominal protrusion. Paraostomal hernias and transit reconstitution, associated with CTSA change performed on day 70.*

#### **5. Specifications**

The therapeutic uses of CTSAs can be numerous. As we previously stated, we emphasize in our experience the diabetic foot, extensive and complex coverage deficits, contained laparotomies and post skin tumor resections, awaiting the biopsy results for an eventual margin enlargement and reconstruction (**Figures 6** and **7**) [38–42]. CTSAs can cover bone, cartilage and tendon exposures, being a simple alternative for the management of complex wounds, becoming an intermediate coverage for some patients and definitive for others.

#### **6. Conclusions**

The distinctive characteristics of CTSAs (from living donor, full-thickness skin, and cryopreserved, therefore viable tissues) permits the obtention of a new type of coverage, which we have called intermediate coverage, easy to use, more economical than current alternatives and with numerous clinical indications.

### **Acknowledgements**

The present study is an initial clinical experience, not a clinical trial, and was conducted under the supervision of the National Coordination of Organ and Tissue Procurement and Transplantation of the Chilean Ministry of Health.

### **Conflict of interest**

The authors declare no conflict of interest.

### **Appendices and nomenclature**


### **Author details**

Marcelo Fonseca<sup>1</sup> \*, Aldo Cañete<sup>2</sup> , Dino Ibaceta<sup>1</sup> , Catalina Buchroithner<sup>3</sup> , Florencia Disi<sup>4</sup> and Juan Olivares<sup>5</sup>

1 Department of Burns and Plastic Surgery, Dr. Ernesto Torres Galdames Hospital, Iquique, Chile

2 Organ and Tissue Procurement and Transplantation Unit, Dr. Ernesto Torres Galdames Hospital, Iquique, Chile

3 Departament of Dermatology, Dr. Ernesto Torres Galdames Hospital, Iquique, Chile

4 Department of Pathology, Dr. Ernesto Torres Galdames Hospital, Iquique, Chile

5 Department of Radiology, Dr. Ernesto Torres Galdames Hospital, Iquique, Chile

\*Address all correspondence to: mfon777@hotmail.com

© 2021 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

*Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds DOI: http://dx.doi.org/10.5772/intechopen.99125*

#### **References**

[1] Janis J, Kwon R, Attinger C. The new reconstructive ladder: modifications to the traditional model. Plast Reconstr Surg. 2011; 127, 205S-212S.

[2] Gottlieb LJ, Krieger LM. From the reconstructive ladder to the reconstructive elevator. Plast Reconstr Surg. 1994;93:1503– 1504.

[3] DiDomenico L, Emch K, Landsman A, Landsman A. A Prospective Comparison of Diabetic Foot Ulcers Treated With Either a Cryopreserved Skin Allograft or a Bioengineered Skin Substitute. Wounds, 2011; 23(7), 184-189.

[4] Leon-Villapalos J, Eldardiri M, Dziewulski P. The use of human deceased donor skin allograft in burn care. Cell and tissue banking, 2010; 11 (1), 99-104.

[5] Labuz D, Asch M, Buchmiller T. Use of Cadaveric Skin Graft for Staged Gastroschisis Repair in a Premature Infant. Neonatology, 2020; 117(5), 628-632.

[6] Gaucher S, Khaznadar Z, Gourevitch JC, Jarraya M. Skin donors and human skin allografts: evaluation of an 11-year practice and discard in a referral tissue bank. Cell and Tissue Banking, 2015; 17(1), 11–19.

[7] Dantzer E. Indicaciones de los sustitutos cutáneos y de los aloinjertos. EMC-Cirugía Plástica Reparadora y Estética, 2015; 23 (1): 1-14.

[8] Gaucher S, Jarraya M. Aloinjertos cutáneos en la cirugía del gran quemado. EMC-Cirugía Plástica Reparadora y Estética, 2009; 17(1): 1-10.pt

[9] Burd A, Chiu T. Allogenic skin in the treatment of burns. Clin Dermatol 2005; 23 (4): 376-387.

[10] Lazzeri D, Pantaloni M, Agostini T. Homografts and the Rejection Phenomenon: from burn care to organ transplantation. Plast Reconstr Surg 2010; 126(5), 1802-1803.

[11] Ben-Bassat H. Performance and safety of skin allografts. Clinics in dermatology, 2005; 23(4), 365-375.

[12] Dantzer E. Indicaciones de los sustitutos cutáneos y de los aloinjertos. EMC-Cirugía Plástica Reparadora y Estética, 2015; 23 (1): 1-14.

[13] Khoo TL, Halim AS, Saad AM, Dorai AA. The application of glycerolpreserved skin allograft in the treatment of burn injuries: an analysis based on indications. Burns 2010 36(6), 897-904.

[14] González F, Vera F, Alcayaga R, González F. Análisis crítico de la baja tasa de donación de órganos en Chile. Rev Med Chile 2020; 148: 242-251.

[15] Zúñiga-Fajuri A, Merino M, Urtubia *M. Una* mirada al origen, funcionamiento y desafíos del nuevo sistema de donación y trasplantes chileno. Rev Med Chile 2018; 146: 780-785.

[16] Zidan S, Eleowa S. Banking and use of glycerol preserved full-thickness skin allograft harvested from body contouring procedures. Burns, 2014 40 (4), 641-647.

[17] Friedland J, Maffi T. MOC-PS (SM) CME Article: Abdominoplasty. Plast Reconstr Surg 2008; 121(4), 1-11.

[18] Ministerio de Salud. Gobierno de Chile. Norma general técnica para el procuramiento, preservación e implante de tejidos. 2018.

[19] Morales-Olivera J, Plasencia J, Vázquez X. Cambios histológicos dérmicos tras pérdida masiva de peso y su repercusión en la herida quirúrgica en abdominoplastia. Cirugía Plástica Ibero-Latinoamericana, 2019; 45(3), 275-283.

[20] Light D, Arvanitis G, Abramson D, Glasberg S. Effect of weight loss after bariatric surgery on skin and the extracellular matrix. Plast Reconstr Surg 2010; 125(1), 343-351.

[21] Martínez-Flores F, Sandoval-Zamora H, Machuca-Rodriguez C, Barrera-López A, García-Cavazos R, Madinaveitia-Villanueva J. Banco de piel y tejidos: un modelo operativo para la recuperación y preservación de aloinjertos de piel y tejidos. Cirugía y Cirujanos 2016; 84(1), 85-92.

[22] Pegg DE. Viability assays for preserved cells, tissues, and organs. Cryobiology 1989;26:212–31.

[23] Castagnoli C, Alotto D, Cambieri I, Casimiri R, Aluffi M, Stella M, et al. Evaluation of donor skin viability: fresh and cryopreserved skin using tetrazolioum salt assay. *Burns* 2003; **29**: 759-67.

[24] Gupta S. Optimal use of negative pressure wound therapy for skin grafts. International wound journal, 2012, vol. 9, p. 40-47.

[25] Stefanowska J, Zakowiecki D, Cal K. Magnetic resonance imaging of the skin. Journal of the European Academy of Dermatology and Venereology, 2010 24 (8), 875-880.

[26] Pomahac B, Garcia J, Lazar A, Tilney N, Orgill D. The skin allograft revisited: A potentially permanent wound coverage option in the critically ill patient. Plast Reconstr Surg 2009; 123 (6), 1755-1758.

[27] Knobloch K, Vogt P. Allograft skin as a permanent tissue repair: to mesh or not?. Plast Reconstr Surg 2010; 125(2), 750-751.

[28] Cuono C, Langdon R, Birchall N, Barttelbort S, McGuire J. Composite autologous-allogeneic skin replacement: development and clinical application. Plast Reconstr Surg 1987; 80(4), 626-637.

[29] Henn D, Chen K, Maan Z, Greco A, Moortgat Illouz S, Bonham C. et al. Cryopreserved human skin allografts promote angiogenesis and dermal regeneration in a murine model. International Wound Journal, 2020. 17 (4), 925-936.

[30] Burke J, Yannas I, Quinby W, Bondoc C, Jung W. Successful use of a physiologically aceptable artificial skin in the treatment of extensive burn injury. Ann Surg. 1981;194:413.

[31] Heimbach D, Luterman A, Burke J, Cram A, Herndon D, Hunt J et al. Artificial dermis for major burns. A multi-center randomized clinical trial. Ann Surg. 1988;208:313.

[32] Climov M, Bayer L, Moscoso A, Matsumine H, Orgill D. The role of dermal matrices in treating inflammatory and diabetic wounds. Plast Reconstr Surg 2016; 138(3S), 148S-157S.

[33] Monclús E, Perales A, Sanz E, Reola E, Agulló A. Utilización de matrices dérmicas en quemaduras. Cirugía Plástica Ibero-Latinoamericana, 2020;46, 39-46.

[34] Lee L, Porch J, Spenler W, Garner W. Integra in lower extremity reconstruction after burn injury. Plast Reconstr Surg. 2008;121:1256–1262.

[35] Schiavon M, Francescon M, Drigo D, Salloum G, Baraziol R, Tesei J. et al. The use of Integra dermal regeneration template versus flaps for reconstruction of full-thickness scalp defects involving the calvaria: A cost– benefit analysis. Aesthetic plastic surgery 2016; 40(6), 901-907.

*Procurement and Use of Cryopreserved Total Skin Allograft in Complex Wounds DOI: http://dx.doi.org/10.5772/intechopen.99125*

[36] Roa R, Taladriz C. Uso actual de sustitutos dérmicos en cirugía reparadora. Revista chilena de cirugía, 2015, vol. 67, no 6, p. 647-652.

[37] Fonseca M, Cañete A, Ibaceta D, Gomez J, Santander M, Acuña P, Mandriaza L et al. Procuramiento y uso de aloinjertos cutáneos de piel total criopreservados obtenidos de pacientes sometidas a abdominoplastía. Rev. Cirugia. 2021;74(1). Disponible en: doi: 10.35687/s2452-4549%Y00%i1227 [Accessed 30 may. 2021].

[38] Bejarano P, Levi D, Nassiri M, Vincek V, Garcia M, Weppler D. et al. The pathology of full-thickness cadaver skin transplant for large abdominal defects: a proposed grading system for skin allograft acute rejection. The American journal of surgical pathology, 2004. 28(5), 670-675.

[39] Michielin O, Van Akkooi A, Ascierto P, Dummer R, Keilholz U. Cutaneous melanoma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology 2019, 30(12), 1884-1901.

[40] Álvaro-Afonso F, García-Álvarez Y, Lázaro-Martínez J, Kakagia D, Papanas N. Advances in dermoepidermal skin substitutes for diabetic foot ulcers. Current vascular pharmacology, 2020 18(2), 182-192.

[41] Gordon A, Alfonso A, Nicholson J, Chiu E. Evidence for healing diabetic foot ulcers with biologic skin substitutes: a systematic review and meta-analysis. Annals of plastic surgery, 2019. 83(4S), S31-S44.

[42] DiDomenico L, Emch K, Landsman A, Landsman A. A Prospective Comparison of Diabetic Foot Ulcers Treated With Either a Cryopreserved Skin Allograft or a Bioengineered Skin Substitute. Wounds, 2011. 23(7), 184-189.

### *Edited by Madhuri Gore*

Wounds with full thickness or deep partial thickness skin loss require skin grafts to achieve closure and minimize functional and aesthetic effects of healing. This book presents a comprehensive overview of skin grafts for wound closure. Section I includes three chapters that discuss established methods of wound bed preparation as well as new agents and methods. Section II includes three chapters that provide basic information about skin grafts and grafting procedure techniques.

Published in London, UK © 2022 IntechOpen © Micke Jonsson / iStock

Skin Grafts for Successful Wound Closure

Skin Grafts for Successful

Wound Closure

*Edited by Madhuri Gore*