What is the best flap for reconstructing a forehead basal cell carcinoma (BCC) defect?

Forehead BCC Reconstruction: Flap Selection

For forehead basal cell carcinoma defects, the paramedian forehead flap is the gold standard reconstruction method, offering superior functional and cosmetic outcomes with excellent tissue match for color, texture, and thickness. 1, 2

Primary Treatment Considerations Before Reconstruction

Before selecting any flap, ensure complete tumor extirpation is the primary event, as the best reconstructive effort fails in the face of tumor recurrence 1:

• Mohs micrographic surgery is mandatory for forehead BCC given the H-zone location, which constitutes high-risk independent of size 3
• MMS achieves 99% 5-year cure rates for primary BCC versus 88-90% with standard excision 3
• If MMS is unavailable, standard excision requires minimum 5-10mm margins with frozen section control 3
• Never proceed with flap reconstruction until negative margins are confirmed intraoperatively, as tissue rearrangement requires complete margin assessment before closure 3

Forehead Flap: The Preferred Option

The paramedian forehead flap represents the best method for repair of extensive facial defects in this location 1:

• Provides optimal color, texture, and thickness match for forehead reconstruction 1, 2
• Successfully used for defects ranging 2-6cm with no recurrence at 1-4 year follow-up 1
• Can be designed as complete vascular island flaps for defects up to 8cm diameter 4
• Achieves satisfactory functional and cosmetic outcomes in 72.7% of patients 5

Technical Considerations for Forehead Flaps

• In Asian patients, thicker skin and pigmentation require careful flap design and thinning to optimize outcomes 2
• Secondary defects can be closed with advancement flaps of the scalp, with donor sites covered using split-thickness skin grafts from the upper limb 6
• Expect temporary complications including median area suffering and possible cerebrospinal fluid leak in bone-invasive cases, but excellent 5-year results 4
• Keloid formation occurs in approximately 4% of patients 1

Alternative Reconstruction Options

Local flaps are reserved for small to medium defects (<2cm) where forehead flap would be excessive 2, 5:

• Local flaps were used in 77.3% of head/neck BCC defects overall, but forehead location specifically benefits from forehead flap 5
• Split-thickness skin grafts are acceptable only for low-risk scenarios with linear closure not feasible, but provide inferior cosmetic results 3, 5

Critical Pitfalls to Avoid

• Never use flap reconstruction if margins are positive or uncertain - this is an absolute contraindication requiring re-excision first 3, 7
• Do not underestimate defect size - forehead BCCs with 7-year history of incomplete excisions can reach 5.2cm with bone invasion 6
• Avoid split-thickness grafts as primary reconstruction for visible forehead defects, as they provide poor color match and contour 2, 5
• Do not delay reconstruction in multiple stages unless bone reconstruction is required - single-stage excision with immediate forehead flap reconstruction is preferred 1

Reconstruction Algorithm

Step 1: Confirm complete excision with Mohs surgery or frozen section control 3

Step 2: Assess defect size:

• Defects >2cm or full-thickness: Paramedian forehead flap 1, 2
• Defects <2cm, superficial: Consider local advancement/rotation flaps 2, 5
• Bone involvement: Forehead flap with calvarial bone grafting if needed 4

Step 3: Execute reconstruction with attention to:

• Flap thinning in patients with thick skin 2
• Vascular island design for larger defects 4
• Secondary defect management with scalp advancement 6