Plastic surgery and skin

CHAPTER 19 Plastic surgery and skin

Plastic surgery has evolved from the innovation of techniques concerning the movement and reconstruction of soft tissue defects by the movement of autologous, distant and allogeneic tissue. Knowledge of anatomy, vascularity, wound healing and vessel, nerve and tendon reconstructive techniques are applied. Excision of benign and malignant tumours of the skin and soft tissue (sarcoma) with subsequent reconstruction of resulting defects forms a large part of the workload. Breast reconstruction following partial or total mastectomy defects, soft tissue defects due to trauma and burns and congenital hand, urogenital and craniofacial abnormalities such as cleft lip and palate are also addressed using these techniques. Elective and traumatic hand surgery and reconstruction forms a large subspecialty. Plastic surgeons often work with other specialties to reconstruct defects that cannot close directly, e.g. orthopaedics (open lower limb fractures), general surgeons and gynaecologists (perineal defects), cardiothoracic surgeons (sternal dehiscence and chest wall defects), neurosurgeons (craniofacial defects), and head and neck surgeons (facial reconstruction following tumour excision and trauma, facial palsy correction). The importance of aesthetics in these reconstructions has led to the refinement of cosmetic surgery which forms the minority of the workload. However the recent increased numbers of obese patients undergoing bariatric surgery has increased the volume of referrals for body contouring procedures (abdominoplasty, belt lipectomy, thigh lift, breast reduction/mastopexy, brachioplasty).

Providing skin cover

Direct closure

Following excision of simple skin lesions or debridement of necrotic tissue in small wounds, the edges may approximate without tension and without deforming neighbouring structures such as the eyebrow, nose, lip or eyelid. Direct closure with simple interrupted or continuous suturing techniques is usually the best approach in such circumstances. Eversion of skin edges is essential with the choice of suture and timing of removal related to the anatomical site. Planned excisions are best performed along relaxed skin tension lines to orientate scars into natural skin creases.

Healing by secondary intention

Where wounds will not close without tension, small defects with a vascularized bed, rather than exposed bone, tendon or prosthesis can be allowed to heal by secondary intention using appropriate dressings. It is remembered, however, that such wounds will heal slowly with contraction which may distort local structures and limit motion if sited over a joint. Such scars can become hypertrophic and therefore problematic. Good results from secondary intention can be seen after excision of small skin cancers in the inner canthal region and may be the most appropriate choice in lower limb ulcers compromised by venous insufficiency where skin grafts are less likely to survive or a patient is not fit for a surgical procedure.

Skin graft

A graft tissue is removed completely from one part of the body and inset onto another site. It is separated from its blood supply and therefore depends on being placed on a healthy vascular bed for its revascularization.

Split-skin graft

This consists of the epidermis and upper papillary dermis. This may be shaved with either a freehand knife or a power dermatome. A thin split-skin graft is approximately 0.25 mm thick. The usual donor sites include arms and thigh. The donor site heals by re-epithelialization under semi-occlusive dressings over 10 days, which can be delayed by infection.

Split-skin grafts are used in the resurfacing of burns, and to cover defects after removal of larger skin tumours. The skin graft revascularizes or ‘takes’ over 3–14 days. Disadvantages include post-graft contracture, lack of resistance to trauma, and absence of normal skin properties, e.g. suppleness, hair growth. The graft can be passed through a ‘mesher’, which creates multiple holes so that the graft looks like a string vest. Wide meshing allows large areas to be covered, and enables easier contouring and egress of underlying blood. A disadvantage is that the final result also resembles a string vest because the interstices heal by epithelialization alone, as they contain no dermal elements. A ‘tie over’ pressure dressing can be applied to prevent movement and keep all parts of the graft in contact with the bed or ‘quilting’ sutures can stitch the graft to the vascular bed.

Full thickness graft (Wolfe graft)

This consists of the epidermis and dermis and therefore includes all skin elements, e.g. hair follicles, sweat glands. Only areas of thin skin can be used as donor sites. Main uses are for facial areas and hands. Usual donor sites include supraclavicular, postauricular, submammary, antecubital and inguinal areas. The donor area requires closure and if this cannot be closed primarily a split-skin graft may be required.

Advantages include the fact that full thickness grafts include all skin elements, are more supple, withstand trauma and undergo the least contraction. Disadvantages include limited donor site area and increased failure of take (compared with split-skin). Successful ‘take’ depends on the same factors as split-skin grafting. A ‘tie over’ dressing should be used, often with added ‘quilting’ sutures.

Factors affecting skin graft take

Skin grafts take over a period of several days. Vascularization commences over the first 2–3 days and is overlapped by a subsequent phase of remodelling and graft maturation lasting several weeks/months. This process is therefore dependent on patient, wound bed and operative factors. The key is good vascularity. If a patient is poorly perfused, for example if peripherally vasoconstricted by noradrenaline administration, is in shock by whatever cause or is a diabetic or peripheral arteriopath, then the graft is less likely to establish. The wound bed needs to be well-debrided and uncontaminated, well vascularized – fat and fascia are less likely to take grafts than muscle, and free from infective organisms especially as Pseudomonas aeruginosa and Group A Streptococcus species which digest compromised tissue. Operative and dressing technique ensuring meticulous haemostasis prior to insetting the graft prevents a haematoma coming between the graft and the bed, and quilting sutures and/or a firm tie over dressing will help to prevent shear stresses damaging the fragile blood vessels revascularizing the graft. The thicker the graft, the more metabolic demands it has to survive and the longer it takes to revascularize, therefore thin grafts are more likely to take than thick split or full thickness grafts.

Flaps

A flap is a section of tissue transferred, carrying its own blood supply. They can be defined by their composition, e.g. skin (cutaneous), fasciocutaneous, adipofascial, or muscle with or without skin or bone. They can be local (raised from an area sharing a border with the defect) and move by advancement, rotation or transposition. These can be geometrically designed to rely on the unnamed vasculature from the base of the flap (random pattern → Fig. 19.1) or based on a named or identified vessel – the pedicle, e.g. groin flap, deltopectoral flap or on a vessel perforating from the deeper tissues. These pedicled flaps do not necessarily share a border with the defect (regional), and can be moved into the defect around a pivot point, related to the axis around the pedicle. General indications for flap cover include: avascular areas, e.g. exposed bone or joint surfaces, exposed major blood vessels, irradiated areas or areas to undergo radiotherapy. (For a selection of pedicled flaps, see Figure 19.2.)

Figure 19.1 (A) Some random pattern flap designs used for facial defects and (B) their resultant scars. (a) Bilateral V-Y advancement flaps, move together to complete the primary (excised) defect, without raising eyebrow. The secondary (flap) defects can be closed directly. (b) Rhomboid flap recruits adjacent mobile skin as a transposition flap to cover the primary defect, yet allows direct closure of the secondary defect. (c) Bilobed flap utilizes two transposition flaps recruiting mobile tissue from dorsum of bridge of nose to cover the secondary defect of the transposition flap used to cover the primary defect. (d) Cheek rotation flap utilizes skin laterally via a cheek-lid margin incision extending in the pre-auricular line. (e) Glabellar ‘hatchet’ flap rotates and advances mobile skin between the brows to cover the primary defect. The secondary defect is closed in a V-Y fashion.

Figure 19.2 Some of the more commonly used pedicled flaps (a–i):

Free flaps

The blood supply to the flap is completely divided and the flap transferred to another area of the body where revascularization is affected by microvascular anastomosis. Free flaps may be composed of muscle, fasciocutaneous tissue, bone (e.g. fibula, scapula, iliac crest, radius) or a combination of these. Advantages include single-stage reconstruction, a wide choice of donor sites allowing better tailoring and choice of a flap to suit the defect without the constraint of a fixed pedicle and a good success rate (up to 95%). Disadvantages include long operating time and the need for specialized equipment and expertise. (For a selection of free flaps, see Figure 19.3.)

Figure 19.3 Some of the more commonly used free flaps (a–h):

‘Surgical’ skin lesions: principles of management (→ Table 19.1)

• Simple excision for straightforward clinically diagnosed lesions, e.g. skin tags, sebaceous cysts

• Excision biopsy if risk of malignancy, e.g. small pigmented lesions where change may have occurred recently

• Incisional biopsy, e.g. for ulcers which have failed to heal and there is need to exclude malignancy or vasculitis

• Wide excision of adequate margin and depth, e.g. for confirmed malignant lesions

• Radiotherapy for basal cell carcinoma may be an alternative to surgery, especially in sites where skin preservation is important

• Remember that skin lesions may be a manifestation of systemic disease.

TABLE 19.1 ‘Surgical’ skin lesions

Benign
Epidermis	Pedunculated papilloma, wart, seborrhoeic keratosis, keratoacanthoma
Dermis	Pyogenic granuloma, fibrous histiocytoma, keloid
Appendages	Furuncle, carbuncle, hidradenitis suppurativa, sebaceous cyst, dermoid cyst, pilonidal sinus
Subcutaneous	Lipoma, neurofibroma
Melanotic	Intradermal naevus, blue naevus, compound naevus, spitz naevus, congenital naevus
Vascular	Campbell de Morgan spots, haemangiomas, capillary/venous/arteriovenous/lymphatic malformations, spider naevi, glomus tumours
Premalignant
Epidermis	Actinic (solar) keratosis, Bowen’s disease, erythroplasia of Queyrat (penis)
Malignant
Epidermis	Basal cell carcinoma, squamous cell carcinoma
Dermis	Kaposi’s sarcoma, secondary deposits
Appendages	Sebaceous carcinoma (rare), sweat gland carcinoma (rare)
Subcutaneous	Liposarcoma, neurofibrosarcoma
Melanotic	Malignant melanoma
Vascular	Angiosarcoma (rare)

Common benign lesions

Epidermis

Pedunculated papillomas (skin tags)

These small polypoid lesions occur in adults, most frequently on the trunk, neck, axilla and groin. They may catch on clothes and bleed, and are often cosmetically unacceptable. They are removed by excision under local anaesthetic. Small skin tags may be treated by tying a fine ligature around the base, which leads to necrosis.

Warts (verrucae vulgaris)

These are caused by papovavirus, and usually occur in the second decade of life. They are common on fingers, hands and soles of feet (verrucae plantaris). Plantar warts may be very painful. Resolution of warts may occur spontaneously. Treatment may be by curettage, freezing with liquid nitrogen or application of keratolytic agents, e.g. podophyllin.

Seborrhoeic keratoses

These are found in elderly patients, and are often multiple, well-demarcated raised ‘stuck on’ lesions with varying degrees of pigmentation. It may be difficult to differentiate from malignant melanoma if deeply pigmented. Treatment is to leave alone or treat by surgical excision or curettage.

Keratoacanthoma

This is a nodular lesion with a central crater containing a keratin ‘plug’. They progress rapidly in 2 weeks to 2 months. Probably of viral aetiology, they often show spontaneous regression. Occasionally, they are difficult to distinguish from squamous cell carcinomas. Treatment is by excision biopsy or close observation, if the lesion is obviously regressing.

Dermis

Pyogenic granuloma

This is a dark red nodule of exuberant granulation tissue and polymorphs. There is rapid initial growth, often at the site of trauma. Occasionally, the surface may ulcerate and then must be distinguished from amelanotic melanoma. Treatment is by excision.

Fibrous histiocytoma

This is a well-circumscribed deep reddish-brown tumour. On inspection, it may be mistaken for a malignant melanoma. However, palpation reveals a hard consistency due to the dense fibrous stroma. Treatment is by excision.

Keloid

This involves excessive deposition of collagen beyond and above the wound itself and is covered by normal epithelium. It must be distinguished from a hypertrophic scar in which the wound becomes broad and raised – the latter usually settles within 6 months. Keloid may increase after 6 months. Black Africans and the young are particularly affected. It may follow burns. Treatment is by intralesional injection of steroid, pressure garment therapy, applying silicon-impregnated dressings; or for refractive, problematic lesions, radiotherapy after excision is an option.

Skin appendages

Boil (furuncle)

This is an infection in a hair follicle usually caused by Staphylococcus aureus. It can occur in any part of the body but is more common in the head, neck, axilla and groins. Diabetes, immunosuppression and general debility are predisposing conditions. Multiple boils (furunculosis) are common in diabetics. Any patient presenting with boils should have the urine tested for sugar.

Usually, they are self-limiting and heal when pus has discharged. Antibiotics should be avoided except in the following situations:

• ‘Dangerous’ areas of the face, i.e. between the orbit and angle of the mouth where venous drainage is into the cavernous sinus – cavernous sinus thrombosis may occur

• Multiple boils with surrounding cellulitis in diabetics and immunosuppressed patients where septicaemia is a risk.

Carbuncle

An infection which dissects through the dermis and subcutaneous tissues to form connecting channels, some of which open to the surface. There is considerable induration and pus discharges through the sinuses. The back of the neck is a common site. Treatment is with antistaphylococcal antibiotics, e.g. flucloxacillin, with desloughing and adequate drainage of the abscesses if necessary.

Hidradenitis suppurativa

A chronic disease of skin and subcutaneous tissue in apocrine gland-bearing areas, e.g. axilla, groin, perineum and perianal areas. The involved area is indurated, fibrotic and inflamed with sinuses draining pus. Staph. aureus is the usual organism grown but occasionally coliforms may be cultured. Treatment is initially by antibiotics. Abscesses are incised and drained. Advanced cases may need wide excision with or without skin grafting. Severe perianal disease may require a diverting colostomy prior to skin grafting.

Sebaceous cysts

These are common on the scalp, face, neck, and back and are soft or firm and spherical. They contain cheesy sebaceous material, which may become infected and discharge. They are attached to the skin and a punctum is usually seen at the point of attachment. Treatment is by excision under local anaesthetic.

Pilonidal sinus

This chronic infection in the sinus is caused by penetration of hairs into skin and subcutaneous tissues. Infection leads to pilonidal abscesses. The sinus leads to a cavity filled with hair and granulation tissue. Common sites include posteriorly in the midline over the sacrococcygeal area and natal cleft (usually hirsute males with sedentary occupations); between the fingers in hairdressers; occasionally umbilicus, axilla and nipple. Differential diagnosis includes perianal fistulae, hidradenitis suppurativa, simple boils. Treatment includes:

• Deroofing the track, removing the hairs and packing; the surrounding skin should be shaved until the sinuses have healed

• Injection of the sinuses with methylene blue, followed by wide excision of all tracts until no dye is seen and either packing, primary suture or reconstruction of large defects using local flaps can be carried out under GA

• For pilonidal abscesses, incising, curetting and packing.

Disorders of the nails

Ingrowing toenail (IGTN)

A common condition, it usually appears on the great toe, particularly the lateral side. Caused by a combination of tight shoes and paring the nail downwards into the nail fold rather than cutting it transversely. The sharp edge of nail then grows into the nail fold producing ulceration, infection, and granulation tissue.

Treatment

Non-infected

Give advice on correct cutting of nails, i.e. transversely. Avoid tight, pointed shoes. Tuck a pledget of cotton wool soaked in mild antiseptic under the corner of the nail to lift it out of the soft tissue. Soak feet in warm water regularly.

Infected

With mild infection, it may be possible to adopt the above regimen in addition to the administration of antistaphylococcal antibiotics. If this fails carry out the following:

• Simple nail avulsion with curettage of infected granulation tissue under local anaesthetic. Antistaphylococcal antibiotics should be administered.

• Wedge excision. Lateral or medial nail and nail bed are removed together with granulation tissue and germinal matrix. Liquefied phenol may be applied to the germinal matrix to ensure complete removal.

• Zadik’s procedure. This is reserved for recurrent IGTN. The nail is avulsed and the germinal matrix completely excised after raising a skin flap to expose it. To ensure complete removal of the germinal matrix liquefied phenol is applied after protecting the skin. The nails should not re-grow after this procedure.

Complications

Recurrence may occur. This is common after simple avulsion. Spikes of nail may occasionally re-grow after a Zadik’s procedure. Infection may occur and it is appropriate to give a course of antistaphylococcal antibiotics prophylactically. Osteomyelitis and septic arthritis may occur after Zadik’s procedure.

Onychogryphosis

This is a ‘ram’s horn’ deformity of the toenail. The nail thickens and curls over the end of the toe as it grows. Common in the elderly, it may follow trauma to the nail in the younger patient. It can be treated by either cutting the nail with bone forceps or grinding the nail down. Avulsion is always followed by recurrence. Zadik’s operation is curative.

Nail bed lesions

Haematoma

There is a history of trauma, e.g. trapping, or dropping a heavy object on the nail. Very painful. A haematoma is evacuated by piercing the nail with a red-hot paper clip. Small haematomas following trivial injury may closely simulate subungual melanoma. Haematomas grow out with growth of the nail. If there is any doubt, biopsy should be carried out.

Melanoma

Subungual malignant melanoma is not uncommon. The lesion does not grow out with the nail. Biopsy is necessary. If the diagnosis is confirmed, amputation of the digit is required.

Subungual exostosis

This nearly always affects the great toe. It occurs in adolescents and young adults. It lifts the overlying nail and causes deformity. Diagnosis is confirmed by radiograph. Treatment is to remove the nail and excise the underlying bony nodule.

Glomus tumour

See Lesions of vascular origin, below.

Subcutaneous tissues

Lipoma

This is a common, benign tumour of fatty tissue. It is soft, lobulated and pseudofluctuant and the overlying skin appears normal. It is slow growing. Treatment is by excision. Multiple lipomas may occur. These need to be distinguished from neurofibromata by biopsy of at least one lesion. Occasionally, there may be multiple tender lipomas on the trunk (Dercum’s disease). Treatment of lipoma is by excision, which is curative. Liposarcomatous change may rarely occur in a benign lipoma.

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Jun 14, 2017 | Posted by admin in GENERAL SURGERY | Comments Off

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