Burns Flashcards

Question

Classifications of skin flaps

Answer 1

Classification Flaps can be classified via their tissue type, blood supply, or location. Tissue Type For tissue types, this is based on the compositions that are utilised in the flap, including cutaneous flap, fasciocutaneous flap, musculocutaneous flap, or muscle flaps Blood Supply Based on blood supply, three definitive types of flap are possible: Axial flap – a designated subcutaneous artery that runs beneath the flaps longitudinal axis (the artery can be a direct, facsiocutaneous, or musculocutaneous artery) Random flap – no designated named artery that provides blood supply to the flap; blood supply via the subdermal plexus Pedicled (or perforator) flap – the tissue is completely raised on a named vessel from the donor site and then transferred to the recipient site; this can be as a pedicled flap or free flap Location Subtypes When defined by location, flaps can be classified as either local, regional, or free flaps Local flaps are harvested from a contiguous site and are commonly used for facial defects (Fig. 6), fingertip injuries, or defects on the limb. These can be further classified into: Advancement flap – The skin is moved directly forward Rotation flap – The skin is rotated around a pivot point to cover an adjacent defect Transposition flap – Moves laterally in relation to the pedicle to cover an adjacent defect Regional (or pedicled) flaps are harvested from the same anatomical region but not directly adjacent. The attached skin (or pedicle) will be tunnelled under the intact tissue, or laid over intact skin forming what is known as a skin bridge, which can then detached from the donor site in a second procedure. Free (or distant) flaps are harvested from a different anatomical region entirely. The tissue and named fasciocutaneous artery are separated from the donor site before being reattached at the recipient site using microsurgical techniques. Examples of free flaps are seen in Table 2.

Answer 2

Pluripotent cells of the stratum basale layer of the epidermis

Answer 3

Long term UV exposure Psoriasis Fitzpatrick type 1 skin Immunosuppression Genetic sydrome- xeroderma pigmetosa, gorlinsyndrome

Answer 4

Nodular – most common (50-60%), commonly a pink pearly nodule with telangiectasia, and can become ulcerated or encrusted; subtypes include cystic, pigmented, or keratotic Superficial – (10-15%) erythematous scaly plaques with a thread-like border, and may bleed or ulcerate Morphoeic – more uncommon, presenting as thickened and sclerosing plaques with poorly defined borders; highest risk of incomplete excision and often prone to recurrence after treatment Basosquamous – a mixed basal cell and squamous cell malignancy, with an infiltrative growth pattern and often are more aggressive

Answer 5

Trichoepithelioma (a rare benign tumour of the hair follicle), Keratoacanthoma (rapidly-growing tumour of the skin derived from the glands surrounding a hair follicle), or a cutaneous Squamous Cell Carcinoma

Answer 6

Factors such as tumour subtype, size, anatomical location, and histological diagnosis will impact how a BCC is managed: Low-risk BCCs are small, well-circumscribed lesions superficial type lesions that do not meet any of the high-risk criteria High-risk BCCs include those occurring in the young (<25yrs) or immunocompromised patients, recurrent lesions, lesions on the nose, lips, ears, or around the eyes, lesions with poorly defined margins, and all non-nodular subtypes of BCC Multiple management options are available BCCs. Superficial disease can often be treated with non-surgical options alone, which include: Cryotherapy (or CO2 ablation) Curettage and electrodissection – 75% cure rate (95% for smaller lesions <2cm) Immune response modulator – Topical imiquimod 5% cream (for superficial BCCs) Topical chemotherapy – 5-fluorouracil 5% cream (for superficial BCCs) Photodynamic therapy – Uses light therapy together with a topical photosensitising agent (for superficial BCCs) Radiotherapy – usually reserved for the older age group, achieves ~90% cure rates Surgical Management The mainstay of surgical management is with excision biopsy. The margins required are between 3-5mm, depending on how demarcated the border is and the location of the lesion. Higher excision margins are required for recurrent BCCs (5mm) or high-risk histological subtypes. If there is sufficient skin laxity in the region, the defect can be closed directly. However, some may require local, regional or free flap or skin grafts. Lesions which are close to vital anatomical structures, have indistinct margins, or are recurrent should be considered for Mohs’ micrographic surgery.

Answer 7

malignant tumour of keratinocytes, arising from the epidermal layer of the skin

Answer 8

Cumulative prolonged exposure to UV light, such as excessive sunbed use Chronic wounds and inflammation A SCC arising in chronic ulcers and scars (particularly burns scars) is known as a Marjolin’s ulcer Immunosupression Pre-malignancy conditions, such as Bowen’s disease or actinic keratoses Smoking (particularly in lip SCC)

Answer 9

other forms of skin cancer, such as BCC or melanoma. Other differentials to consider include pre-malignant conditions (e.g. Bowen’s disease or Actinic Keratosis, Fig. 3), Keratoacanthoma (rapidly growing keratinising nodules, well-demarcated), verrucous carcinoma, or cutaneous horns.

Answer 10

The first line management for resectable SCC is surgical; non-surgical options are only used as adjuncts or where surgery is not feasible. Surgical Treatment The standard surgical treatment is with an excision biopsy, with the peripheral margins taken dependent on the risk status of the patient: low risk ≥ 4mm high risk ≥ 6mm very high risk ≥ 10mm The deep margins taken should be the next clear surgical plane (or in scalp lesions, down to the galea) Further wide local excision (with likely delayed reconstruction), Mohs micrographic surgery, or adjuvant radiotherapy may be offered to patients with one or more involved or close margins if there are any high risk factors. Dermatologists may perform curettage and cautery for immunocompetent patients who have small (<1cm), clinically low risk SCC Non-Surgical treatment Multiple non-surgical options are also available to patients with SCC in certain cases. Primary radiotherapy may be a treatment option if surgery is not feasible or would result in an unacceptable functional or aesthetic outcome. Adjuvant radiotherapy is used for patients with close or involved margins if further surgery is not possible, or for patients with clear margins but multiple high risk factors where the chance of local recurrence is high. Immune Checkpoint Inhibitors can be used in locally advanced SCC where curative surgery or radiotherapy is not no reasonable, or in cases of metastatic SCC. Chemotherapy is often used as a third line, in people who are not suitable for immune checkpoint inhibitors, however is often poorly tolerated in frailer or co-morbid patients, and usually has a short lived response.

Answer 11

https://teachmesurgery.com/plastic-surgery/skin-cancer/melanoma/

Answer 12

UV exposure – both recreational (e.g. sunbed use) and occupational Age – the majority of melanomas occur in patients aged >50yrs Previous melanoma – represents an 8-10x increased risk Skin tone – incidence is highest in Caucasian groups (although prognosis in darker skin is worse due to delayed diagnosis) Most commonly affects Fitzpatrick Type 1 and 2 skin, the two palest skin types Family history – approximately 10% of patients will have a positive family history for melanoma Predisposing conditions – albinism, xeroderma pigmentosum, atypical mole syndrome, >50 typical naevi, immunosuppression (i.e. organ transplant recipient)

Answer 13

Patients with a tissue diagnosis of melanoma should be referred to the specialist skin MDT (ssMDT), where definitive excision margins, further investigations, and treatment are determined. In all cases of melanoma, ongoing sun protection advice should be given, with concurrent Vitamin D supplementation and advice on prevention (see Prognosis). Wide Local Excision A wide local excision refers to excision of a larger area of tissue from the original site of the melanoma. Its aim is to improve local control of melanoma by removing micrometastases. It is indicated is nearly all cases of melanoma, including those with clear histological margins on the excision biopsy. The exact peripheral margin used in the wide local excision is guided by the Breslow thickness (Table 2). The deep margin should always be down to the deep fascia Breslow Thickness Sentinel Lymph Node Biopsy Sentinel lymph node biopsy (SLNB) aims to identify whether or not there is any melanoma in the primary draining lymph node(s) within a regional lymph node basin. Current NICE guidelines recommend offering SLNB to patients with melanoma with a Breslow thickness >1 mm, without clinically apparent nodal or metastatic disease. If the lymph nodes are clinically suspicious (i.e. palpable) or radiologically suspicious (i.e. enlarged on imaging) then fine needle aspiration cytology (FNAC) should be performed. When obtaining patient content for SLNB, it is important to emphasis that it is a staging and prognostic procedure only. It is usually performed at the same time as the wide local excision. Staging Imaging should be performed in patients with stage IIc melanoma who have not had SLNB, or stage III and IV melanoma. Typically, this involves a CT chest-abdomen-pelvis and MRI brain (or whole body PET-CT with additional imaging of the brain). Melanoma is staged using the TNM classification; the clinical TNM (cTNM) stage is then updated with information after surgery to give the pathological stage (pTNM). The AJCC staging (Table 3) groups the TNM stages to guide treatment and prognosis Metastatic Disease Unfortunately, metastatic disease is relatively common in melanoma. Both regional and distant metastases can be managed using various immunotherapy and chemotherapy agents. The immunotherapy agents most commonly used are: Ipilimumab – a monoclonal antibody that inhibits cytotoxic T lymphocyte antigen 4 (CTLA 4), which would normally down regulate T cell activation Pembrolizumab and Nivolumab – monoclonal antibodies that attach to the PD1 receptor on T cells so that the T cells cannot be switched off and remain active Vemurafenib and Dabrafenib – both are BRAF kinase inhibitors that block the activity of the BRAF V600E mutation which otherwise causes persistent MAPK pathway activation leading to uncontrolled cell proliferation Talimogenelaherparepvec (TVEC) – an oncolytic immunotherapy derived from herpes simplex virus type-1 which causes tumour lysis and the release of tumour-derived antigens; it is injected directly into the metastasis

Burns Flashcards

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