Minor Surgery in Primary Care
Minor surgery in primary care encompasses a range of procedures including excision of skin lesions, incision and drainage of abscesses, and joint injections, performed under local anaesthesia with appropriate training and governance frameworks.
Key Facts
Common GP minor surgery procedures: excision of skin lesions, incision and drainage of abscesses, cryotherapy, cautery, joint/soft tissue injections, removal of ingrown toenails All excised lesions must be sent for histological examination to exclude malignancy Lidocaine 1% (max dose 3mg/kg or 200mg in adults) or lidocaine 1% with adrenaline (max 7mg/kg) for local anaesthesia 2-week-wait referral for suspicious skin lesions: asymmetry, irregular border, colour variation, diameter >6mm, evolving (ABCDE criteria for melanoma) Cryotherapy (liquid nitrogen): for viral warts, seborrhoeic keratoses, actinic keratoses (pre-malignant) Joint injection (corticosteroid + local anaesthetic): for OA flares, tendinopathy, bursitis; max 3-4 injections per year per joint Infection rate for minor surgery in primary care: approximately 1-3% (similar to hospital settings) Clinical governance: appropriate training, consent, resuscitation equipment, infection control, audit
Overview
Key Facts
Minor surgery is a core GP skill that provides convenient, cost-effective access to procedures in the community. Appropriate patient selection, consent, and clinical governance are essential.
Common Procedures
- Excision/shave biopsy of skin lesions (sebaceous cysts, lipomas, moles, skin tags)
- Incision and drainage of abscesses
- Cryotherapy (viral warts, seborrhoeic keratoses, actinic keratoses)
- Cautery/curettage
- Joint and soft tissue injections
- Ingrown toenail surgery (partial nail avulsion + phenolisation)
- Wound closure (suturing, skin adhesive)
- Ear syringing/microsuction
Training and Governance
- RCGP minor surgery certificate or equivalent training
- Regular CPD and audit
- Appropriate premises, equipment, and resuscitation facilities
- Written consent for all procedures
- Chaperone policy
- Histology pathway for all excised specimens
Clinical Presentation
Pre-Procedure Assessment
- Clinical assessment of lesion/condition
- Determine whether lesion is suitable for GP excision or requires specialist referral
- Assess suitability for local anaesthesia
- Anticoagulation status (warfarin, DOACs — generally safe for minor procedures; do not stop)
- Allergy history (lidocaine allergy very rare)
Indications for GP Excision
- Clinically benign skin lesions: sebaceous cysts, lipomas (<5cm), benign moles, skin tags, dermatofibromas
- Diagnostic excision of atypical lesions (if not suspicious enough for 2-week-wait)
Lesions Requiring 2-Week-Wait Referral (NOT GP Excision)
- Suspected melanoma (ABCDE criteria, dermoscopic concern)
- Suspected SCC (non-healing ulcerated/keratotic nodule)
- Suspected BCC in difficult anatomical site (nose, around eyes, ears)
- Rapidly growing lesions
Red Flags
- ABCDE criteria for melanoma: Asymmetry, Border irregularity, Colour variation, Diameter >6mm, Evolving
- Non-healing skin ulcer >8 weeks — consider SCC
- Pearly papule with telangiectasia — consider BCC
- Hard, fixed subcutaneous lump — consider malignancy
- Lesion growing rapidly — urgent referral
Differential Diagnosis
| Lesion | Features | Management |
|---|---|---|
| Sebaceous cyst (epidermoid) | Punctum, soft, mobile, may become infected | Excision |
| Lipoma | Soft, mobile, subcutaneous, lobulated | Excision if symptomatic |
| Skin tag | Pedunculated, skin-coloured, friction areas | Snip excision, cryotherapy |
| Seborrhoeic keratosis | 'Stuck on' appearance, waxy, well-demarcated | Cryotherapy or curettage |
| Actinic keratosis | Rough, scaly, sun-exposed skin, pre-malignant | Cryotherapy, topical 5-FU, diclofenac gel |
| Melanoma | ABCDE criteria, changing lesion | 2-week-wait referral |
| BCC | Pearly papule, rolled edges, telangiectasia | 2-week-wait referral |
| SCC | Keratotic nodule, ulcerated, sun-exposed area | 2-week-wait referral |
Diagnosis / Investigation
Pre-Procedure
- Clinical examination and documentation (description, measurements, photograph)
- Dermoscopy if trained (for pigmented lesions)
- INR check if on warfarin (safe to proceed if INR <3.5 for minor procedures)
Post-Procedure
- All excised tissue must be sent for histology — this is a critical safety requirement
- Histology result review and patient follow-up
- Further management based on histology (re-excision if incomplete, referral if malignant)
Documentation
- Consent form
- Description of procedure, anaesthesia used, complications
- Specimen sent for histology (labelled and orientated if appropriate)
- Follow-up plan communicated to patient
Management
Local Anaesthesia
- Lidocaine 1% (10mg/mL): max dose 3mg/kg (200mg in 70kg adult = 20mL)
- Lidocaine 1% with adrenaline 1:200,000: max dose 7mg/kg; longer duration; reduces bleeding
- Adrenaline: safe for digits (evidence supports use; traditional teaching of avoiding is outdated)
- Infiltrate slowly with fine needle (25G or 27G); wait 3-5 minutes for effect
Excision Technique
- Mark lesion with skin marker
- Elliptical excision: 3:1 length-to-width ratio; fusiform shape; long axis along Langer lines
- Excision margin: 2mm for benign lesions
- Achieve haemostasis (cautery, pressure)
- Closure: subcuticular or interrupted sutures; Steri-Strips for superficial wounds
- Dressing and wound care instructions
Joint Injection
- Aseptic technique essential (infection risk approximately 1 in 10,000-77,000)
- Triamcinolone acetonide 40mg (large joints) or 10mg (small joints) + lidocaine 1%
- Post-injection flare: occurs in 2-10%; self-limiting
- Advise relative rest for 24-48 hours
- Maximum 3-4 injections per joint per year
Incision and Drainage of Abscess
- Local anaesthetic (field block around abscess; infiltrating into abscess is painful and less effective)
- Cruciate incision over point of maximal fluctuance
- Express pus, break down loculations
- Pack cavity lightly with ribbon gauze
- Send pus for MC&S
- Antibiotics only if cellulitis, systemic infection, or immunocompromised
Referral Criteria
- Any lesion suspicious for malignancy: 2-week-wait dermatology/plastics
- Incomplete excision of BCC/SCC/melanoma on histology: urgent re-referral
- Lesions in cosmetically sensitive areas: consider specialist referral
- Large or deep lipomas (>5cm or subfascial): surgical referral
- Recurrent or complex abscesses: consider underlying cause
Prognosis
- Minor surgery complications: infection 1-3%, haematoma 1-2%, wound dehiscence 1-2%
- Incomplete excision of BCC: recurrence rate 17-38% (vs 1-2% with complete excision)
- Histological surprise (unexpected malignancy on histology): approximately 1-2% of excised lesions
- Joint injection: symptom relief in 60-80% lasting 4-12 weeks; repeated injections may accelerate cartilage loss
- Abscess drainage: cure rate >90% with adequate drainage; recurrence 10-15% (higher with MRSA)
Other Relevant Information
Local Anaesthetic Maximum Doses
| Agent | Max Dose | Volume (1% Solution) |
|---|---|---|
| Lidocaine 1% | 3mg/kg (max 200mg) | 20mL |
| Lidocaine 1% + adrenaline | 7mg/kg (max 500mg) | 50mL |
| Bupivacaine 0.25% | 2mg/kg (max 150mg) | 60mL |
ABCDE Criteria for Melanoma
| Feature | Description |
|---|---|
| A — Asymmetry | Lesion not symmetrical |
| B — Border | Irregular, ragged edges |
| C — Colour | Multiple colours (brown, black, red, white, blue) |
| D — Diameter | >6mm (or any size if changing) |
| E — Evolving | Changing size, shape, or colour |