Case Report: A modified Karapandzic flap with bilateral V–Y advancement for reconstruction of a large full-thickness lower lip defect after squamous cell carcinoma excision

Purpose Reconstruction of full-thickness lower lip defects involving more than two-thirds of the vermilion remains surgically challenging. The conventional Karapandzic flap is a labial artery–based musculomucocutaneous flap requiring continuous incisions extending from the labiolabial crease through the labiomandibular fold to the mental crease, often resulting in extensive scarring. Moreover, this technique requires meticulous identification and preservation of the labial artery and perioral nerves, leading to greater technical demands and prolonged operative time, particularly for less experienced surgeons. Herein, we introduce a modified Karapandzic flap technique using bilateral V–Y advancement flaps for lower lip reconstruction following squamous cell carcinoma (SCC) excision. Methods A 74-year-old man presented with SCC of the lower lip. The lesion measured 4.3 × 1.8 cm, and a wedge-shaped wide excision with a 5-mm surgical margin was performed. The resulting full-thickness defect measured 5.3 × 2.3 cm, involving more than two-thirds of the lower lip. Instead of extending incisions across the entire lower lip, bilateral V–Y advancement flaps were designed on both lateral aspects and elevated with partial release of the depressor anguli oris muscle to allow medial mobilization. Results Complete flap survival and satisfactory wound healing were observed without major complications. At approximately four months, oral competence was maintained according to the patient, without liquid leakage, drooling, or food spillage, and without restrictions on food types. During maximal voluntary mouth opening, the intercommissural distance was 2.5 cm, the vertical oral aperture was 4 cm, and the distance between externally marked reference points corresponding to the palpated upper and lower incisal positions was 6 cm. Two-point discrimination was 5 mm at the central and bilateral lower lip sites. Postoperative microstomia resulted in reduced oral aperture, for which secondary commissuroplasty had been anticipated as part of a staged reconstructive plan. Conclusion Bilateral V–Y advancement based on the modified Karapandzic concept may provide a reconstructive option for selected extensive full-thickness lower lip defects without formal neurovascular dissection. Although flap survival and oral competence were maintained in this case, postoperative microstomia and the anticipated need for secondary commissuroplasty should be considered during surgical planning.