Introduction
Surgeons performing facial reconstruction often face complex decisions when choosing the most appropriate method to reconstruct skin and soft tissue defects resulting from lesion excision, trauma, infection, or chronic wounds. These decisions have become even more critical in light of the rising incidence of skin cancer, driven by increased outdoor activity and greater exposure to ultraviolet radiation [1]. Additionally, even older patients are showing growing interest in not only functional but also cosmetic outcomes after reconstructive surgery in the facial region due to the visibility of scars. Local tissue available for reconstruction may be limited compared to other body areas, and the choice of surgical method can be constrained by the risk of disrupting cosmetic landmarks. Primary closure, while favored for its simplicity, shorter time required for execution, and quicker recovery, often results in longer scars relative to the size of the lesion. This is even more so in cases of skin cancer requiring radical resection, often accompanied by the formation of a “dog-ear” deformity and distortion of surrounding structures.
Skin grafting, although effective in reducing scar size in proportion to the lesion, carries inherent risks of donor site scarring and graft necrosis. It also generally requires a longer treatment period and leaves significant differences in graft texture and color compared to the surrounding normal skin, as well as the potential for marginal scarring [1,2]. Local flaps, including rotation, bilobed, Limberg, and V-Y advancement flaps, are commonly used in facial reconstruction because they offer several advantages, including flexibility, better match in texture and color with surrounding tissue, less conspicuous scarring, faster healing, and shorter hospital stays [1-4]. The Limberg flap, also known as the rhomboid flap, was introduced by Alexander Alexandrovich Limberg in 1946. The flap’s straightforward design, technique, and wide applicability across various body regions have led many surgeons to utilize it for pilonidal sinus disease, as well as in head and neck, hand, and breast reconstruction [3,5-7]. However, most studies on the traditional Limberg flap focus on pilonidal sinus reconstruction, and the few studies addressing the facial region are limited mainly to the midface [5,6,8]. Consequently, there is a lack of research specifically exploring the application of Limberg flaps in facial reconstruction. In this study, we introduce a novel modified Limberg flap that reduces flap size compared to the traditional Limberg flap and aim to evaluate its feasibility as a viable option for small to medium-sized facial defect reconstruction.
Methods
We conducted a retrospective chart review study on 26 patients treated at Daejeon Eulji Medical Center between October 2020 and December 2022 who underwent wide excision of suspected malignant tumors followed by modified Limberg flap reconstruction. The data collected included patient demographics such as sex, age, and medical history, as well as lesion characteristics such as location, size, and type. Outcome measures included complications and scar satisfaction. Patients who visited the outpatient clinic for their final follow-up at 6 months postoperatively were asked to rate their surgical outcomes on a 10-point visual analog scale (VAS) ranging from 0 to 10, where 0 indicates normal skin and 10 represents the poorest scar. This assessment covered scar satisfaction and other relevant factors. This study was approved by the Institutional Review Board (IRB No. EMC 2021-09-007) of Daejeon Eulji Medical Center, which waived the requirement for patient informed consent due to the retrospective nature of the study, and also study was conducted according to the Declaration of Helsinki (June 1964) and its subsequent amendments. Patients in the photographs provided written consent for their photographs to be published and used.
Surgical technique
Punch biopsies were initially done for histological diagnosis of lesions. With confirmed basal cell carcinomas (BCC), a safety margin of 2–3 mm was implemented, while for squamous cell carcinomas (SCC) and squamous cell carcinoma in situ (Bowen’s disease; BD), a 4 mm safety margin was used [9]. Lesions such as melanocytic nevus and actinic keratosis, which could potentially lead to skin cancers such as melanoma or SCC, were also excised with a 2–4 mm margin.
Our modified Limberg flap was utilized in cases where creating a flap equal in size to the defect was difficult—either due to limited amounts of surrounding skin, the need to avoid distortion of adjacent structures, or concerns about poor scar outcomes. The flap design essentially follows the same method as the traditional rhombic-shaped Limberg flap, with alternating angles of 120° and 60° at each corner (Fig. 1A). However, these angles can be modified to within 90°. In a standard Limberg flap application, the line interconnecting points D and F runs parallel to the relaxed skin tension line and perpendicular to the line of maximum extensibility (LME), thereby minimizing tension during donor site closure and reducing scar formation (Fig. 1B). However, in areas including the nasal alar, philtrum, and suprabrow region, we recommend designing the D-F line to run parallel to the LME in order to avoid complications such as eyebrow elevation or philtrum shortening.
As shown in Fig. 1B, the Limberg flap allows for four potential flap sites. Flap design begins at one end of the shorter diagonal axis of the rhombus (e.g., point B or D). From that point, a line of equal length is drawn parallel to the BD line, ending at point E. Then, from point E, a second line is drawn parallel to the corresponding side of the defect, determining point F. Among these potential flap sites, preference was given to areas with higher skin laxity, designating them as donor sites for incisions and subsequent flap elevation. However, if a preferred site involved vital structures such as facial nerves or posed a risk of skin color mismatch or disruption of anatomical landmarks—particularly in areas like the lips, scalp, or eyebrows—an alternative site was selected based on a balance of sufficient skin laxity and minimal risk of structural distortion. When no significant difference exists among the four potential flap sites, we recommend designing the flap laterally to minimize scar visibility.
Modified Limberg flap technique
A flap was designed with side lengths approximately 20% to 50% shorter than those of the original defect, prior to incision. Subsequently, one or more of the defect’s corners excluding the D corner were sutured at the subdermal layer using absorbable sutures (Vicryl 5-0) to reduce the defect size (Fig. 1C). Any the other three corners (A, B, and C) can be sutured individually or together, considering skin tension and potential deformation.
Flap incisions were made using a No. 15 blade, followed by dissection along the subdermal plane to elevate the flap. The elevated flap was then transposed to the defect site. During this process, the flap corner points labeled D’, E, and F are Atransferred to the defect corner points labeled B, C, and D, respectively.
When dog-ear correction was necessary, a superficial excision of approximately 1–2 mm was performed at the redundant point. After subcutaneous suturing of each corner and midpoint of each side of the flap with Vicryl 5-0 absorbable sutures, the skin layer was sutured using either nylon 6-0 or Black Silk 6-0 non-absorbable sutures, followed by the application of a mild compressive foam dressing. Sutures were removed 7 to 10 days after surgery. For post-operational scar management, silicone gel and sheets were used for 2 to 3 months. Laser scar treatment was not performed.
Results
In total, 28 Limberg flap procedures were performed in 26 patients, with a total of 18 patients being followed up for 6 months postoperatively. Postoperative pathological examinations revealed 22 cases of malignancy. These included four cases of BD, five cases of SCC, six cases of BCC, and one case of basosquamous cell carcinoma, with BCC being the most frequent. Additionally, there were two cases of other benign tumors (actinic keratosis and seborrheic keratosis). Of these 18 patients, 11 were women and seven were men. The mean patient age was 78.95 years (range, 59–94 years) (Table 1). The distribution of lesion location was as follows: six cases on the cheek, four in the periauricular area, three on the nose, and one each on the forehead, scalp, philtrum, eyebrow and submandibular area. After wide excision, the length of the major axis of the defects were as follows: 1.0–1.9 cm in 11 cases, 2.0–2.9 cm in six cases, and 3.0–3.9 cm in one case (Table 2). Some complications were observed, including one case of partial flap margin necrosis and two cases of small hematoma. One patient required reoperation for further excision due to margin involvement confirmed by final pathology results following malignant tumor resection. Excluding the eight patients who were lost to follow-up or passed away during the 6-month follow-up period, the mean VAS score of the remaining 18 patients was 3.6 (range, 1–7).
Case 1
A 74-year-old woman presented to our institution with an ulcerative lesion on her philtral area. A punch biopsy performed by the dermatology department revealed characteristics suggestive of BCC. Wide excision and a modified Limberg flap procedure were carried out subsequently under local anesthesia. The flap was elevated from the outer margin of the excision defect, and the size of the defect was reduced before flap transposition to minimize nasal distortion. At the 6-week postoperative check, the outcome was deemed acceptable (Fig. 2).
Case 2
A 78-year-old woman came to our institution with a blackish patch on the border area between her forehead and left frontal scalp. A punch biopsy revealed characteristics suggestive of BCC. Following this, a wide excision and modified Limberg flap procedure was carried out under local anesthesia. To minimize hairline disruption, the defect was first partially closed by suturing approximately 5 mm of its edge near the scalp, thereby reducing its size. A correspondingly smaller flap was then designed and elevated to match the adjusted defect. Photographs taken at postoperative 2 weeks display a generally favorable cosmetic outcome (Fig. 3).
Case 3
A 76-year-old male patient presented to our institution with a blackish plaque-like lesion in his left preauricular area. Punch biopsy results pointed toward a BCC, for which a wide excision and modified Limberg flap procedure were carried out with the additional aim of minimizing damage to the temporal branch of the facial nerve located near the lesion. To accomplish this, the flap was elevated from the upper aspect of the defect. Furthermore, approximately 5–6 mm of the upper and lower edges near the defect were sutured, leading to a 30% to 40% reduction of the defect size prior to executing the Limberg flap procedure. Photographs taken at the 8-week postoperative point showed a relatively fine scar (Fig. 4).
Discussion
Facial reconstruction for patients with tumors, trauma, or other acquired wounds frequently presents significant challenges for reconstructive surgeons. This is especially true in cases of malignant skin tumors, where wide excision is necessary for obtaining adequate safety margins. Both aesthetic and functional aspects should be considered in such cases. Primary closure is the simplest surgical method and also has the advantage of allowing preservation of skin color, texture, and harmony with surrounding structures. However, this approach may be challenging for defects with a diameter of 2 cm or larger, as it can result in a noticeable linear scar of 5–6 cm or more, and may not suitable in areas where disruption of anatomical landmarks is a concern. As a result, when primary closure is not suitable, full-thickness skin grafts or local flaps are often considered as secondary options. In addition to the challenges associated with wound management, such as longer hospitalization and the need to care for both the graft and donor site, skin grafts may also result in lower patient satisfaction compared to local flaps due to mismatches in skin color, texture, and the presence of marginal scarring. Previous research has shown that local flaps tend to yield superior results over skin grafts in various aspects [1]. Given the significant drawbacks of primary closure and the concern about scarring with skin grafts, many patients may benefit from the Limberg flap. Therefore, we have defined the indications for the modified Limberg flap as follows: (1) circular or quadrangle lesion; (2) medium size defect (2–4 cm diameter); (3) anatomical landmark or vital structure near lesion; (4) limited amount of skin surrounding lesion; and (5) patient sensitive to scarring or does not want a separate donor site.
Among the various types of local flaps, the Limberg flap is notable for its ability to be designed in the direction which distributes tension most ideally across the wound for tissue realignment, minimizing scar formation. This makes it an optimal choice for surgeons seeking versatility in flap selection [10].
Moreover, the Limberg flap offers a range of adaptable modifications. We utilized our modified Limberg flap to address defects of various sizes and locations on the face. In facial reconstruction, especially near the eyelids, nasal alar, and mouth where minimizing landmark disruption is crucial, the classic Limberg flap, designed with dimensions equal to those of the defect (1:1 ratio), can result in distortion.
In these circumstances, our modified version of the Limberg flap provides a means to reduce anatomical landmark disruption while serving as an effective reconstructive option. By suturing one edge of the defect to reduce its size prior to flap transposition, the required flap length could be reduced to approximately half of the original defect dimension, resulting in a total flap area reduction of 30% to 70% compared to the initial defect area. We discovered that using a rhomboid shape without strict adherence to specific 60° and 120° angles, and reducing flap size by 30% to 70% when necessary to prevent landmark distortion, had minimal impact on tension or flap survival. This method facilitated the coverage of variously shaped defects, including circular defects, square defects with angles close to 90°, and asymmetric-shaped defects resulting from additional excisions, through straightforward transposition and edge suturing. As discussed in the introduction and surgical technique, factors such as flap redundancy, skin elasticity, and adjacent anatomical landmarks can influence the choice of flap elevation site, which can also be based on the surgeon’s preference.
This technique can be particularly useful in cases like case 1 and 2, where surgery is performed near nasal ala and hairline landmarks, or in cases like case 3, where critical structures such as arteries and nerves are located nearby. To minimize dog-ear deformities, we recommend trimming approximately 5mm around the defect. When dog-ear deformities do occur, limiting their excisions to under 2 mm can help to reduce scar length.
In some cases, such as after Mohs surgery, currently the preferred approach for skin cancer excision, the final permanent biopsy may reveal positive margins despite a negative frozen section. In such instances, reoperation involves excising only the involved portion of the original surgical site or a section of the flap. Even in these situations (Fig. 5), our modified Limberg flap allows for straightforward revision with minimal impact on flap survival or scar formation. An additional excision of approximately 2–3 mm is typically sufficient and does not compromise the outcome.
Among the various different facial regions, the nose presents specific challenges for reconstruction due to its high sebum secretion, limited skin laxity, complex three-dimensional anatomical structure, and presence of cartilage. When reconstructing the nasal tip and ala, commonly used techniques include the bilobed flap, V-Y advancement flap, and nasolabial turnover flap [1,4,10]. The Limberg flap is also preferred for its ability to minimize postoperative deformities, as is the bilobed flap; however, the bilobed flap may appear more conspicuous in Asian patients compared to Caucasians [2]. Despite the fact that it may not consistently produce significantly superior results compared to other local flaps [4], the Limberg flap remains a viable option for nasal reconstruction for defects with a diameter less than 2.0 cm (Fig. 5). However, for the lower eyelid, it is advisable to avoid using the Limberg flap for lesions in the middle and medial portions, as these areas are likely to experience post-surgical tension on the eyelid, which can lead to secondary deformities due to scarring.
Complications observed included one case of partial flap margin necrosis and two cases of hematoma. The patient with partial necrosis underwent a corrective procedure involving a 2 mm excision around the necrotic area 3 weeks post-surgery, a process akin to scar revision. The necrosis occurred at the most tension-prone point B of the defect. The other two complication patients were successfully treated using conservative methods. However, the relatively short follow-up period and relatively high number of patients lost to follow-up may limit the significance of this observation.
The relatively high level of patient satisfaction concerning scarring and other post-surgical outcomes suggests the superiority of our modified Limberg flap in these contexts. This could be partly due to the somewhat reduced patient expectation related to skin cancer diagnosis. However, from the surgeon’s perspective, our modified Limberg flap is a technique that can produce favorable results compared to other reconstruction methods, offering a viable option for covering small to medium size facial skin defects. This approach minimizes deformities of surrounding structures and is considered a relatively satisfactory aesthetic choice.