Trapdoor effect in nasolabial flaps. Causes and corrections.

Area of Science:

• Plastic Surgery
• Wound Healing

Background:

• The trapdoor effect is a scar deformity characterized by elevated, bulging tissue within a U-, C-, or V-shaped scar.
• Several theories exist, including lymphatic/venous obstruction, scar hypertrophy, excess tissue, beveled edges, and scar contracture.

Purpose of the Study:

• To investigate the predominant cause of the trapdoor effect in nasolabial flaps.
• To evaluate treatment modalities for trapdoor deformities.

Main Methods:

• Analysis of data to identify the primary cause of trapdoor deformities in nasolabial flaps.
• Review of surgical techniques for correcting mild, moderate, and severe trapdoor deformities.

Main Results:

• Scar contracture was identified as the predominant cause of the trapdoor effect in nasolabial flaps.
• Multiple small Z-plasties are indicated for mild to moderate deformities.
• Intralesional triamcinolone acetonide injections may offer a "pharmacologic Z-plasty" effect.
• Marked deformities require a combination of Z-plasties and peripheral undermining.
• Prevention or reduction is achievable with adequate peripheral undermining of the flap recipient site.

Conclusions:

• Scar contracture is the primary driver of the trapdoor effect in nasolabial flaps.
• Surgical interventions like Z-plasties and undermining are effective corrective measures.
• Prophylactic undermining of flap recipient sites can mitigate or prevent trapdoor deformities.