Grafts

Grafts

Grafts are tissues that are transferred without their blood supply and therefore need to be revascularised through the recipient wound bed. To maximise the success of this procedure, the wound bed must be healthy with a good blood supply such - that angiogenesis into the graft tissue can occur. Graft failure - occurs most commonly as a result of shear forces disrupting the graft from the wound bed, infection (particularly with group - A β -haemolytic Streptococcus spp.) and haematoma or seroma formation (which can lift the graft away from the underlying wound bed). Skin grafts are used to achieve wound closure in situations where the skin defects are too large for primary closure and healing by secondary intention may be inappropriate or lead to an unreasonable delay in complete healing. Ther e are two types of skin grafts, depending on the depth at which they are taken ( Figure 47.7 ): /uni25CF - Split-thickness skin grafts consist of epidermis and a variable amount of dermis and are sometimes referred to as Thiersch grafts. They are commonly harvested from the thigh using a dermatome or graft knife to achieve a consis - tent depth ( Figure 47.8 ). It is relatively simple to harvest large areas of skin to reconstruct sizeable defects such as those following a significant burn injury (see Chapter 46 ). The grafted skin can then be meshed or fenestrated to expand and cover a wider surface area as well as avoid the accumulation of an underlying haematoma. The graft is typically sutured, glued or stapled to the recipient site. However, grafts are not entirely robust, for example they can shear o ff , and may contract significantly over time. The donor area usually heals by secondary intention within 2 /uni00A0 weeks by means of simple dressings ( Figure 47.9 /uni25CF Full-thickness skin grafts consist of epidermis and dermis. As they include the entire thickness of the dermis, they retain their elasticity and are less prone to secondary scar contracture. However, this also means that the area harvested is limited by the ability to primarily close the do nor site. The common sites for harvest include the supra clavicular skin, groin crease and posterior auricular region (known as a Wolfe graft), where there is adequate skin lax ity . Full-thickness grafts are commonly used for syndactyly release in the hand, reconstruction of facial defects follow ing skin cancer excision or contracture releases following burns ( Figure 47.10 ). /uni25CF Composite skin grafts are a combination of skin and another tissue type, such as fat or cartilage. A commonly used composite skin graft is to harvest a skin/cartilage graft from the helical root of the ear to reconstruct the alar of the nose following skin cancer excision. A hair-bearing composite scalp graft can be used to reconstruct an eye brow . Nerve grafts are used to reconstruct peripheral nerves (including the brachial plexus) and in the surgical manage ment of facial palsy (by utilising a cross-facial nerve graft) and corneal paraesthesia. Common donor nerves include the sural nerve, medial antebrachial cutaneous nerve and the sensory branch of the posterior interosseous nerve (ideal for digital nerve grafts). Whereas vessels are ‘anastomosed’, nerv John Reissberg Wolfe , 1824–1904, Professor of Ophthalmology , University of Glasgow , UK. ‘coapted’ – typically using epineurial sutures with or without fibrin glue in a tension-free manner. Tendon grafts are utilised for the reconstruction of tendons in the upper and lower extremities as a result of trauma, infection (e.g. leprosy) or neurological injury (peripheral nerve or spinal transection). Commonly used donor tendons include ). palmaris longus, extensor digitorum longus and plantaris. Autologous cartilage g rafts can be used for support and augmentation (such as the cartilaginous framework of a staged reconstruction for microtia, a congenital deformity of the outer ear), to correct contour irregularities (such as the - nasal dorsum) or to repair or resurface damaged joints (such - as the temporomandibular joint or small joints of the hand). - - - - es are

(d) Figure 47.8 Power dermatome harvest of a split-thickness skin graft, with the correct method of providing skin tension (a–d) and applying a sterile dressing (e) . (e) Figure 47.9 Typical appearance of a split-thickness skin graft donor site on the left lateral thigh 6 months after harvest. The mild hyper- pigmentation is expected to fade over time.

Common donor sites include the conchal bowl of the ear (elastic cartilage), the nasal septum (which provides rigid hyaline cartilage) and costal cartilage (a plentiful source of hyaline cartilage). Whereas autograft (i.e. graft harvested from the same individual) is considered the ‘gold standard’ for most elective surgical indications, there are certain circumstances when allografting (i.e. from another individual of the same species) or xenografting (i.e. from another species) might be necessary to minimise donor site morbidity or because of a lack of donor tissue. For example, cadaveric allograft or porcine xenograft may be used as a temporising ‘dressing’ following the initial debridement of an extensive burn or necrotising fasciitis. Skin substitutes are engineered dressings that are designed to facilitate wound healing by replicating as many of the key either replace the epidermal or functions as possible. They can dermal components (or both) and can have either a cellular or acellular dermal matrix. Dermal substitutes include Alloderm ® (human dermal matrix) or Integra (bovine collagen with ® chondroitin and a silastic membrane) whereas Epicel example of an epidermal substitute derived from autologous ® keratinocytes. Apligraf is a double-layered bioengineered skin substitute derived from human fibroblasts and keratinocytes and is licensed for the treatment of diabetic and venous ulcers. Their advantage is one of ready availability (in large quantities if required) without the creation of a donor site defect; however, they are expensive and must be employed using a meticulous surgical technique to avoid failure. Tissue expansion is the creation of extra skin and soft tissue by using a subcutaneous silicone balloon in order to reconstruct locoregional defects. The tissue expander is placed within a subcutaneous pocket and then inflated with saline solution at als via a filling port (which can be regular (e.g. weekly) interv buried or externalised). The overlying skin and soft tissue have viscoelastic properties; in response to the underlying mechani - cal force, they permanently elongate through the processes of ‘creep’ and stress relaxation. Angiogenesis leads to increased vascularity within the expanded skin flap and the local response ® ge flaps to a ‘foreign body’ creates a fibrous capsule. Thus lar can be created that have similar physical and mechanical prop - is an erties to the skin that is to be replaced. Common indications include scalp reconstruction following skin cancer excision

(c) Figure 47.10 Full-thickness skin graft reconstruction of a contact burn to the dorsum of the digits. (b) Full-thickness skin grafts from the groin sutured to the wounds. /uni00A0 bed. (d) Postoperative appearance at 1 year. (d) (a) Post excision of burn wounds. (c) Tie-over dressings applied to avoid shearing of the graft off the wound

(ideal for reconstructing hair-bearing skin), breast recon struction following mastectomy and auricular reconstruction. Occasionally , more than one expander is used to reconstruct complex or large defects, such as giant congenital melano cytic naevi ( Figure 47.11 ). Caution must be exercised w considering expansion of irradiated tissue or in patients with comorbidities including diabetes or connective tissue disorders as wound healing is impaired in these scenarios. Prosthetics are widely used in plastic surgery – ranging from ocular, nasal and auricular to hand pr ostheses. Alloplas tic implants are routinely employed in reconstructive plastic surgery , including titanium plates for cranioplasties (re ® ing lost calvarial bone), porous polyethylene (Medpor implants to augment the facial skeleton (e.g. cheek bones or chin tip) and breast implants. Breast implants comprise an Caleb Hillier Parry , 1755–1822, physician, Bath General Hospital, Bath, UK. Moritz Heinrich Romberg , 1795–1873, German neurologist, Director of the University Hospital, Berlin, Germany . - outer shell (typically a silicone elastomer that may be smooth or textured) and a filling material (saline or silicone gel) and come in a variety of shapes (round or anatomical) and a vast - array of volumes. Implants are prone to capsular contracture, hen ma y interfere with mammographic cancer surveillance and are associated with the development of anaplastic large-cell lym - phoma in a small percentage of cases.

(c) Figure 47.11 Tissue expansion provides local autologous tissue for reconstruction of large defects. (a) Extensive congenital melanocytic naevus of the back with tissue expanders in situ (arrows). (b) Explantation /uni00A0 of in /f_l ated tissue expanders. (c) Advance

/uni00A0 ment of expanded skin /f_l aps to determine the extent of naevus excision. (d) Immedi

ate postoperative appearance after partial excision of the naevus and skin /f_l ap closure. The /f_l aps were subsequently re-expanded to facilitate excision of the residual naevus. (d)

Grafts

Grafts are tissues that are transferred without their blood supply and therefore need to be revascularised through the recipient wound bed. To maximise the success of this procedure, the wound bed must be healthy with a good blood supply such - that angiogenesis into the graft tissue can occur. Graft failure - occurs most commonly as a result of shear forces disrupting the graft from the wound bed, infection (particularly with group - A β -haemolytic Streptococcus spp.) and haematoma or seroma formation (which can lift the graft away from the underlying wound bed). Skin grafts are used to achieve wound closure in situations where the skin defects are too large for primary closure and healing by secondary intention may be inappropriate or lead to an unreasonable delay in complete healing. Ther e are two types of skin grafts, depending on the depth at which they are taken ( Figure 47.7 ): /uni25CF - Split-thickness skin grafts consist of epidermis and a variable amount of dermis and are sometimes referred to as Thiersch grafts. They are commonly harvested from the thigh using a dermatome or graft knife to achieve a consis - tent depth ( Figure 47.8 ). It is relatively simple to harvest large areas of skin to reconstruct sizeable defects such as those following a significant burn injury (see Chapter 46 ). The grafted skin can then be meshed or fenestrated to expand and cover a wider surface area as well as avoid the accumulation of an underlying haematoma. The graft is typically sutured, glued or stapled to the recipient site. However, grafts are not entirely robust, for example they can shear o ff , and may contract significantly over time. The donor area usually heals by secondary intention within 2 /uni00A0 weeks by means of simple dressings ( Figure 47.9 /uni25CF Full-thickness skin grafts consist of epidermis and dermis. As they include the entire thickness of the dermis, they retain their elasticity and are less prone to secondary scar contracture. However, this also means that the area harvested is limited by the ability to primarily close the do nor site. The common sites for harvest include the supra clavicular skin, groin crease and posterior auricular region (known as a Wolfe graft), where there is adequate skin lax ity . Full-thickness grafts are commonly used for syndactyly release in the hand, reconstruction of facial defects follow ing skin cancer excision or contracture releases following burns ( Figure 47.10 ). /uni25CF Composite skin grafts are a combination of skin and another tissue type, such as fat or cartilage. A commonly used composite skin graft is to harvest a skin/cartilage graft from the helical root of the ear to reconstruct the alar of the nose following skin cancer excision. A hair-bearing composite scalp graft can be used to reconstruct an eye brow . Nerve grafts are used to reconstruct peripheral nerves (including the brachial plexus) and in the surgical manage ment of facial palsy (by utilising a cross-facial nerve graft) and corneal paraesthesia. Common donor nerves include the sural nerve, medial antebrachial cutaneous nerve and the sensory branch of the posterior interosseous nerve (ideal for digital nerve grafts). Whereas vessels are ‘anastomosed’, nerv John Reissberg Wolfe , 1824–1904, Professor of Ophthalmology , University of Glasgow , UK. ‘coapted’ – typically using epineurial sutures with or without fibrin glue in a tension-free manner. Tendon grafts are utilised for the reconstruction of tendons in the upper and lower extremities as a result of trauma, infection (e.g. leprosy) or neurological injury (peripheral nerve or spinal transection). Commonly used donor tendons include ). palmaris longus, extensor digitorum longus and plantaris. Autologous cartilage g rafts can be used for support and augmentation (such as the cartilaginous framework of a staged reconstruction for microtia, a congenital deformity of the outer ear), to correct contour irregularities (such as the - nasal dorsum) or to repair or resurface damaged joints (such - as the temporomandibular joint or small joints of the hand). - - - - es are

(d) Figure 47.8 Power dermatome harvest of a split-thickness skin graft, with the correct method of providing skin tension (a–d) and applying a sterile dressing (e) . (e) Figure 47.9 Typical appearance of a split-thickness skin graft donor site on the left lateral thigh 6 months after harvest. The mild hyper- pigmentation is expected to fade over time.

Common donor sites include the conchal bowl of the ear (elastic cartilage), the nasal septum (which provides rigid hyaline cartilage) and costal cartilage (a plentiful source of hyaline cartilage). Whereas autograft (i.e. graft harvested from the same individual) is considered the ‘gold standard’ for most elective surgical indications, there are certain circumstances when allografting (i.e. from another individual of the same species) or xenografting (i.e. from another species) might be necessary to minimise donor site morbidity or because of a lack of donor tissue. For example, cadaveric allograft or porcine xenograft may be used as a temporising ‘dressing’ following the initial debridement of an extensive burn or necrotising fasciitis. Skin substitutes are engineered dressings that are designed to facilitate wound healing by replicating as many of the key either replace the epidermal or functions as possible. They can dermal components (or both) and can have either a cellular or acellular dermal matrix. Dermal substitutes include Alloderm ® (human dermal matrix) or Integra (bovine collagen with ® chondroitin and a silastic membrane) whereas Epicel example of an epidermal substitute derived from autologous ® keratinocytes. Apligraf is a double-layered bioengineered skin substitute derived from human fibroblasts and keratinocytes and is licensed for the treatment of diabetic and venous ulcers. Their advantage is one of ready availability (in large quantities if required) without the creation of a donor site defect; however, they are expensive and must be employed using a meticulous surgical technique to avoid failure. Tissue expansion is the creation of extra skin and soft tissue by using a subcutaneous silicone balloon in order to reconstruct locoregional defects. The tissue expander is placed within a subcutaneous pocket and then inflated with saline solution at als via a filling port (which can be regular (e.g. weekly) interv buried or externalised). The overlying skin and soft tissue have viscoelastic properties; in response to the underlying mechani - cal force, they permanently elongate through the processes of ‘creep’ and stress relaxation. Angiogenesis leads to increased vascularity within the expanded skin flap and the local response ® ge flaps to a ‘foreign body’ creates a fibrous capsule. Thus lar can be created that have similar physical and mechanical prop - is an erties to the skin that is to be replaced. Common indications include scalp reconstruction following skin cancer excision

(c) Figure 47.10 Full-thickness skin graft reconstruction of a contact burn to the dorsum of the digits. (b) Full-thickness skin grafts from the groin sutured to the wounds. /uni00A0 bed. (d) Postoperative appearance at 1 year. (d) (a) Post excision of burn wounds. (c) Tie-over dressings applied to avoid shearing of the graft off the wound

(ideal for reconstructing hair-bearing skin), breast recon struction following mastectomy and auricular reconstruction. Occasionally , more than one expander is used to reconstruct complex or large defects, such as giant congenital melano cytic naevi ( Figure 47.11 ). Caution must be exercised w considering expansion of irradiated tissue or in patients with comorbidities including diabetes or connective tissue disorders as wound healing is impaired in these scenarios. Prosthetics are widely used in plastic surgery – ranging from ocular, nasal and auricular to hand pr ostheses. Alloplas tic implants are routinely employed in reconstructive plastic surgery , including titanium plates for cranioplasties (re ® ing lost calvarial bone), porous polyethylene (Medpor implants to augment the facial skeleton (e.g. cheek bones or chin tip) and breast implants. Breast implants comprise an Caleb Hillier Parry , 1755–1822, physician, Bath General Hospital, Bath, UK. Moritz Heinrich Romberg , 1795–1873, German neurologist, Director of the University Hospital, Berlin, Germany . - outer shell (typically a silicone elastomer that may be smooth or textured) and a filling material (saline or silicone gel) and come in a variety of shapes (round or anatomical) and a vast - array of volumes. Implants are prone to capsular contracture, hen ma y interfere with mammographic cancer surveillance and are associated with the development of anaplastic large-cell lym - phoma in a small percentage of cases.

(c) Figure 47.11 Tissue expansion provides local autologous tissue for reconstruction of large defects. (a) Extensive congenital melanocytic naevus of the back with tissue expanders in situ (arrows). (b) Explantation /uni00A0 of in /f_l ated tissue expanders. (c) Advance

/uni00A0 ment of expanded skin /f_l aps to determine the extent of naevus excision. (d) Immedi

ate postoperative appearance after partial excision of the naevus and skin /f_l ap closure. The /f_l aps were subsequently re-expanded to facilitate excision of the residual naevus. (d)

Grafts

Grafts are tissues that are transferred without their blood supply and therefore need to be revascularised through the recipient wound bed. To maximise the success of this procedure, the wound bed must be healthy with a good blood supply such - that angiogenesis into the graft tissue can occur. Graft failure - occurs most commonly as a result of shear forces disrupting the graft from the wound bed, infection (particularly with group - A β -haemolytic Streptococcus spp.) and haematoma or seroma formation (which can lift the graft away from the underlying wound bed). Skin grafts are used to achieve wound closure in situations where the skin defects are too large for primary closure and healing by secondary intention may be inappropriate or lead to an unreasonable delay in complete healing. Ther e are two types of skin grafts, depending on the depth at which they are taken ( Figure 47.7 ): /uni25CF - Split-thickness skin grafts consist of epidermis and a variable amount of dermis and are sometimes referred to as Thiersch grafts. They are commonly harvested from the thigh using a dermatome or graft knife to achieve a consis - tent depth ( Figure 47.8 ). It is relatively simple to harvest large areas of skin to reconstruct sizeable defects such as those following a significant burn injury (see Chapter 46 ). The grafted skin can then be meshed or fenestrated to expand and cover a wider surface area as well as avoid the accumulation of an underlying haematoma. The graft is typically sutured, glued or stapled to the recipient site. However, grafts are not entirely robust, for example they can shear o ff , and may contract significantly over time. The donor area usually heals by secondary intention within 2 /uni00A0 weeks by means of simple dressings ( Figure 47.9 /uni25CF Full-thickness skin grafts consist of epidermis and dermis. As they include the entire thickness of the dermis, they retain their elasticity and are less prone to secondary scar contracture. However, this also means that the area harvested is limited by the ability to primarily close the do nor site. The common sites for harvest include the supra clavicular skin, groin crease and posterior auricular region (known as a Wolfe graft), where there is adequate skin lax ity . Full-thickness grafts are commonly used for syndactyly release in the hand, reconstruction of facial defects follow ing skin cancer excision or contracture releases following burns ( Figure 47.10 ). /uni25CF Composite skin grafts are a combination of skin and another tissue type, such as fat or cartilage. A commonly used composite skin graft is to harvest a skin/cartilage graft from the helical root of the ear to reconstruct the alar of the nose following skin cancer excision. A hair-bearing composite scalp graft can be used to reconstruct an eye brow . Nerve grafts are used to reconstruct peripheral nerves (including the brachial plexus) and in the surgical manage ment of facial palsy (by utilising a cross-facial nerve graft) and corneal paraesthesia. Common donor nerves include the sural nerve, medial antebrachial cutaneous nerve and the sensory branch of the posterior interosseous nerve (ideal for digital nerve grafts). Whereas vessels are ‘anastomosed’, nerv John Reissberg Wolfe , 1824–1904, Professor of Ophthalmology , University of Glasgow , UK. ‘coapted’ – typically using epineurial sutures with or without fibrin glue in a tension-free manner. Tendon grafts are utilised for the reconstruction of tendons in the upper and lower extremities as a result of trauma, infection (e.g. leprosy) or neurological injury (peripheral nerve or spinal transection). Commonly used donor tendons include ). palmaris longus, extensor digitorum longus and plantaris. Autologous cartilage g rafts can be used for support and augmentation (such as the cartilaginous framework of a staged reconstruction for microtia, a congenital deformity of the outer ear), to correct contour irregularities (such as the - nasal dorsum) or to repair or resurface damaged joints (such - as the temporomandibular joint or small joints of the hand). - - - - es are

(d) Figure 47.8 Power dermatome harvest of a split-thickness skin graft, with the correct method of providing skin tension (a–d) and applying a sterile dressing (e) . (e) Figure 47.9 Typical appearance of a split-thickness skin graft donor site on the left lateral thigh 6 months after harvest. The mild hyper- pigmentation is expected to fade over time.

Common donor sites include the conchal bowl of the ear (elastic cartilage), the nasal septum (which provides rigid hyaline cartilage) and costal cartilage (a plentiful source of hyaline cartilage). Whereas autograft (i.e. graft harvested from the same individual) is considered the ‘gold standard’ for most elective surgical indications, there are certain circumstances when allografting (i.e. from another individual of the same species) or xenografting (i.e. from another species) might be necessary to minimise donor site morbidity or because of a lack of donor tissue. For example, cadaveric allograft or porcine xenograft may be used as a temporising ‘dressing’ following the initial debridement of an extensive burn or necrotising fasciitis. Skin substitutes are engineered dressings that are designed to facilitate wound healing by replicating as many of the key either replace the epidermal or functions as possible. They can dermal components (or both) and can have either a cellular or acellular dermal matrix. Dermal substitutes include Alloderm ® (human dermal matrix) or Integra (bovine collagen with ® chondroitin and a silastic membrane) whereas Epicel example of an epidermal substitute derived from autologous ® keratinocytes. Apligraf is a double-layered bioengineered skin substitute derived from human fibroblasts and keratinocytes and is licensed for the treatment of diabetic and venous ulcers. Their advantage is one of ready availability (in large quantities if required) without the creation of a donor site defect; however, they are expensive and must be employed using a meticulous surgical technique to avoid failure. Tissue expansion is the creation of extra skin and soft tissue by using a subcutaneous silicone balloon in order to reconstruct locoregional defects. The tissue expander is placed within a subcutaneous pocket and then inflated with saline solution at als via a filling port (which can be regular (e.g. weekly) interv buried or externalised). The overlying skin and soft tissue have viscoelastic properties; in response to the underlying mechani - cal force, they permanently elongate through the processes of ‘creep’ and stress relaxation. Angiogenesis leads to increased vascularity within the expanded skin flap and the local response ® ge flaps to a ‘foreign body’ creates a fibrous capsule. Thus lar can be created that have similar physical and mechanical prop - is an erties to the skin that is to be replaced. Common indications include scalp reconstruction following skin cancer excision

(c) Figure 47.10 Full-thickness skin graft reconstruction of a contact burn to the dorsum of the digits. (b) Full-thickness skin grafts from the groin sutured to the wounds. /uni00A0 bed. (d) Postoperative appearance at 1 year. (d) (a) Post excision of burn wounds. (c) Tie-over dressings applied to avoid shearing of the graft off the wound

(ideal for reconstructing hair-bearing skin), breast recon struction following mastectomy and auricular reconstruction. Occasionally , more than one expander is used to reconstruct complex or large defects, such as giant congenital melano cytic naevi ( Figure 47.11 ). Caution must be exercised w considering expansion of irradiated tissue or in patients with comorbidities including diabetes or connective tissue disorders as wound healing is impaired in these scenarios. Prosthetics are widely used in plastic surgery – ranging from ocular, nasal and auricular to hand pr ostheses. Alloplas tic implants are routinely employed in reconstructive plastic surgery , including titanium plates for cranioplasties (re ® ing lost calvarial bone), porous polyethylene (Medpor implants to augment the facial skeleton (e.g. cheek bones or chin tip) and breast implants. Breast implants comprise an Caleb Hillier Parry , 1755–1822, physician, Bath General Hospital, Bath, UK. Moritz Heinrich Romberg , 1795–1873, German neurologist, Director of the University Hospital, Berlin, Germany . - outer shell (typically a silicone elastomer that may be smooth or textured) and a filling material (saline or silicone gel) and come in a variety of shapes (round or anatomical) and a vast - array of volumes. Implants are prone to capsular contracture, hen ma y interfere with mammographic cancer surveillance and are associated with the development of anaplastic large-cell lym - phoma in a small percentage of cases.

(c) Figure 47.11 Tissue expansion provides local autologous tissue for reconstruction of large defects. (a) Extensive congenital melanocytic naevus of the back with tissue expanders in situ (arrows). (b) Explantation /uni00A0 of in /f_l ated tissue expanders. (c) Advance

/uni00A0 ment of expanded skin /f_l aps to determine the extent of naevus excision. (d) Immedi

ate postoperative appearance after partial excision of the naevus and skin /f_l ap closure. The /f_l aps were subsequently re-expanded to facilitate excision of the residual naevus. (d)