Versatility of the Yu flap in lip reconstruction

Dear Editor,

Reconstruction of defects involving up to approximately two-thirds of the lip length is challenging due to the functional and esthetic complexity of this region, as well as the limited number of described surgical options.¹ In this context, the Yu flap represents a valuable alternative.^1,2

First described in 1989,¹ the Yu flap combines three local flaps,³ and can be performed in its classic, inverted, or modified form.^1,3,4

Surgically, the first component is a rhomboid advancement flap that moves into the lip defect from the buccinator área, the second is a rotation-advancement flap that covers the donor site of the first flap, and the third is a buccal mucosal flap that reconstructs the vermilion.¹

The objective of this study is to evaluate the final functional and cosmetic outcomes, as well as patient satisfaction, using a structured questionnaire.

This is a retrospective, observational study of clinical cases involving lip defect reconstruction using the Yu flap technique, performed at our hospital between 2021 and 2025. The study also aimed to assess patients’ perception of the functional and esthetic outcomes of the surgery through a structured questionnaire, administered by telephone to all patients.

The questionnaire included five questions addressing the following post-operative aspects: Ability to drink liquids, ability to eat solid foods, speech function, use of dental prosthesis, and satisfaction with esthetic appearance. Responses were scored on a scale from 1 to 5, according to the patients’ increasing degree of satisfaction.

A total of 7 cases were included: 4 males (57.1%) and 3 females (42.9%), with a mean age at the time of surgery of 75.0 years [Table 1].

Histopathological diagnoses included 6 squamous cell carcinomas and 1 basal cell carcinoma. Complete excision was achieved in all cases except for one squamous cell carcinoma.

Four classic Yu flaps were performed [Cases 1–4 in Table 1], all for tumors located on the lower lip. Representative clinical and surgical images are presented for one of these cases only [Figure 1]. One modified Yu flap was performed [Figure 2], in which the superior releasing incision was not required. One inverted Yu flap was performed [Figure 3], and one inverted bilateral Yu flap was also carried out [Figure 4].

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Figure 1:

Corresponds to Case 1 from Table 1. Male patient, 71 years old. Reconstruction with a classic Yu flap for a lower lip defect. A favorable functional and esthetic outcome was achieved (1-year post-operative).

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Figure 2:

Corresponds to Case 5 from Table 1. Male patient, 86 years old. Reconstruction with a modified Yu flap, without the need for a superior releasing incision. A favorable functional and cosmetic outcome was achieved (2 months post-operative).

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Figure 3:

Corresponds to Case 6 from Table 1. Male patient, 84 years old, with a basal cell carcinoma of the upper lip. An inverted Yu flap was designed to reconstruct the defect after tumor excision. The sequence illustrates the pre-operative tumor, flap design and incision, flap elevation and rotation on the upper lip with advancement of the oral mucosa to reconstruct the vermilion, final in setting and closure, and the post-operative outcomes, demonstrating good oral competence and an excellent esthetic result at 3 months.

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Figure 4:

Corresponds to Case 7 from Table 1. Female patient, 72 years old. A bilateral inverted Yu flap was performed to reconstruct a large central defect of the upper lip. The procedure resulted in a favorable functional and esthetic outcome (3 months post-operative).

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Regarding the patient-reported outcomes from the questionnaires, all parameters showed generally very positive results, especially in post-operative speech ability [Table 1]. No cases of microstomia were observed.

All procedures were performed under local anesthesia with lidocaine and adrenaline, without sedation or general anesthesia. All surgeries were carried out as outpatient procedures, with no need for elective hospitalization or admission due to complications. Post-operative wound care was performed at our department under medical supervision. When applicable, the reintroduction of dental prostheses was carried out on the day of suture removal. Sutures were removed on the 10^th post-operative day in all patients.

There were no cases of infection, dehiscence, or total flap necrosis. The most frequently observed complication was edema and the trapdoor effect which was successfully managed with intralesional corticosteroid injections.

The Yu flap is an excellent option for the reconstruction of significant defects of both the upper and lower lips, demonstrating versatility and favorable cosmetic and functional outcomes. Compared to other described flaps, it is technically more straightforward, faster to perform, and associated with lower morbidity.

The classic Yu flap is most appropriate for reconstruction of lower lip defects, providing a reliable closure while preserving oral competence and minimizing donor site morbidity. The modified Yu flap omits the lateral releasing incision, thereby reducing scar burden and preserving the rotational mobility of the superior flap. In our series, this variant proved effective for the reconstruction of a lateral lower lip defect, achieving both functional and esthetic restoration. The inverted Yu flap is particularly indicated for upper lip reconstruction, in which the flap is rotated in the opposite direction to conform to the natural curvature of the lip and philtrum. Finally, the bilateral inverted Yu flap may be employed for midline or extensive upper lip defects, providing optimal tension distribution and excellent preservation of oral sphincter function.

All procedures in our series were performed under local anesthesia, without sedation or general anesthesia, and, to the best of our knowledge, this is the first published case series to adopt this approach for Yu flap reconstructions.

Moreover, it allows for reconstruction of the vermilion, which is often a challenging aspect of lip repair. In comparison to the Karapandzic flap, the Yu flap offers the additional advantage of reducing microstomia,¹ as evidenced by the preserved oral aperture and satisfactory post-operative oral function observed in our series. Nevertheless, despite these benefits, a certain degree of risk for microstomia remains, particularly in reconstructions involving extensive defects.⁵

With this study, we aim to demonstrate that the Yu flap is a valuable reconstructive option and should always be considered, when appropriate, for large labial defects.