Expanded Forehead Stepped Flaps for Delayed Three-Stage Repair of Midface Skin Lesions

Shengwu ZHENG,Xiongmei HUANG,Jing ZHUANG,Ling ZHANG,Genhui LIN,Yu YANG

ABSTRACT Background The forehead flap is the best flap for nasal defect repair and nasal reconstruction.It is also an ideal option for repairing skin lesions in the midface (including the nasal area,inner area of the cheek,and upper lip of the perioral area).However,the traditional frontal myocutaneous flap is relatively bulky for repairing pure skin lesions.In addition,the original forehead flap is generally not sufficient to cover a large wound area.If a large forehead flap is removed,the donor site cannot be sutured in one stage.In this study,an expanded forehead stepped flap was used to overcome the shortcomings of the traditional frontal myocutaneous flap.Methods In stage one surgery,a rectangular expander (80-100 mL) was implanted on the side of the forehead.The expansion pot was built-in,and the excess expansion amount was 160-200 mL.After 4 weeks of rest,stage two operation was performed to remove the skin lesions in the midface.The pulsation point of the supratrochlear artery on one side was used as the pedicle,and the flap was designed diagonally to the upper region of the opposite side.The flap was designed according to the size and shape of the wound.The distal portion of the flap was separated in the superficial layer of the frontalis muscle,approximately 1.7 cm above the superior orbital edge,and cut into the submuscle.The flap pedicle was cut from the superficial layer of the periosteum to form a stepped flap.Then,the flap was rotated downward to repair the wound in the midface.Five weeks later,stage three of the operation which involved flap pedicle division,was performed.Results Expanded forehead stepped flaps were used in 12 cases with 6-36 months of follow-up.In all cases,the blood supply to the flaps was good,and their color,texture,and thickness matched well with those of the surrounding skin.All patients were satisfied with the outcome of the repair.Conclusion Expanded forehead stepped flaps present an ideal option for repairing wounds after large skin lesion resections in the midface since they have multiple edges from a reliable blood supply,easiness to transfer,and well-matched color,texture,and thickness to those of the surrounding skin of the face to no need for many auxiliary incisions.

KEY WORDS Soft tissue expansion;Forehead flap;Supratrochlear artery;Facial reconstruction

INTRODUCTION

The midface is located in the center of the face,which has a significant influence on the person’s appearance and functions.Therefore,midface reconstructions demand excellent esthetics and functionality.Since there are obvious differences in appearance and texture after skin grafting,as well as changes related to the functional limitations from skin contractures,skin grafting is often the reason for a secondary repair.The best cosmetic and functional results can be achieved by using adjacent skin flaps of similar color and texture to repair the midface[1].As an axial skin flap,the forehead flap is adjacent to the midface.Therefore,it is ideal for repairing wounds after large resections of midface skin lesions[2].The anatomical study by Li Qingfeng’s team showed that the supratrochlear artery has relatively constant cutaneous branches in the supraorbital frontal region[3-4].Based on this anatomical study,we designed the expanded forehead flap as follows:the distal portion of the flap was separated in the superficial layer of the frontalis muscle,and the flap pedicle was cut from the superficial layer of the periosteum to form a stepped flap.The skin thickness of the flap was similar to that of the midface skin.Postrepair surgery was not required.Since 2008,a total of 12 patients with midface skin lesions have been treated using this method with pleasing outcomes,esthetically and functionally.

PATIENTS AND METHODS

Patients

There were 12 patients,including 5 males and 7 females.The mean age of the patients was 13 (range:4-23) years.The most common causes for surgery were congenital melanocytic nevus (7 cases),followed by scarring (4 cases:scars due to isotope treatment of hemangioma,2 cases;scars from trauma,1 case;unacceptable appearance as a result of skin grafting,1 case) and 1 case of capillary malformation.The defects ranged from 3 cm × 4 cm to 5 cm × 7 cm.The lesions were located in the midface,including the nasal area,inner area of the cheek,and upper lip of the perioral area.After the lesions were resected,the wounds were repaired with an expanded forehead stepped flap.

Surgical Techniques

Stage one surgery:expander implantation

An 80-100 mL rectangular expander was chosen.The implanted location was placed on the side of the forehead that was biased toward the lesion in the midface,and the range of forehead dissection was set with methylene blue.The incision was approximately 3 cm long,perpendicular to the frontal stria,and behind the hairline.Blunt dissection was performed under the galea aponeurotica and frontal muscles,and the area was compressed to stop the bleeding.The expander capsule was crimped and placed into the forehead cavity,and saline was injected to fully stretch the expander capsule.Then,the saline was withdrawn until 12-15 mL of saline was left in the expander capsule.The injection pot was placed under the scalp on the incision side.A negative pressure drainage tube was placed in the cavity and removed 2 days after the operation.Five to seven days after expander implantation,a saline injection was performed to expand the soft tissue at a regular rate of 8-12 mL every 3-4 days.The excess expansion amount was 160-200 mL.The second-stage operation was performed 4 weeks after the expansion was completed.

Stage two operation:midface wound repair with expanded forehead stepped flaps

The midface skin lesion was completely resected,bleeding was properly stopped,and a sample of the wound was biopsied.The pulsation point of the supratrochlear artery at the opposing brow of the main area of the expanded flap was used as the pedicle.The flap was designed diagonally to the upper region of the opposite side with a 1.5-2.0 cm width of the pedicle.The flap was designed according to the size and shape of the wound based on the sample.Taking into account the retraction of the flap after removing the expander,the size of the designed flap was 10% greater than the original defect.We separated the flap between the subcutaneous fat and the frontalis muscle,cut into the submuscle at approximately 1.7 cm above the superior orbital rim,and cut the flap pedicle from the superficial layer of the periosteum to form a stepped flap.The flap was then rotated downward to repair the midface wound.If necessary,the subcutaneous fat at the distal end of the flap was further trimmed to form an ultra-thin flap to match the skin thickness of the repair area.Owing to the excessive expansion of the forehead flap in advance,the donor site was able to be sutured directly.A negative pressure drainage tube was placed under the flap and removed after 2 days.The pedicle wound of the rotating flap was covered with a skin graft obtained from the midface skin lesion.

Stage three operation:flap pedicle division

Five weeks after the second-stage operation,the flap pedicle division was performed,and the skin covering the wound of the pedicle was removed.After trimming,the pedicle flap was returned to the area between the eyebrows to restore the eyebrow spacing to normal.The patients were advised to strictly minimize sun exposure for 6 months after surgery to prevent localized pigmentation.

RESULTS

The blood supply to the flaps was good in all 12 patients.All patients were followed up for 6-36 months.The color,texture,and thickness of the flaps matched the surrounding facial skin well,and the outcomes were pleasing.The patients and their dependents were satisfied with the results of the operations.Typical cases are shown in Fig.1 and Fig.2.

DISCUSSION

According to previous literature[2,5-6],the face is divided into five esthetic regions:frontal,orbital,nasal,cheek,and perioral regions.The orbital region can be divided into the upper eyelid area,lower eyelid area,medial canthal area,and lateral canthal area.The cheek region can be divided into the zygomatic area,lateral area,medial area,and cheek area.The perioral region can be divided into the upper lip area,lower lip area,and chin area.The skin lesions in our group of patients mainly involved the nasal area,medial area of the cheek region,and upper lip area of the perioral region,which are located in the center of the face and have a great impact on esthetics.Each patient had a strong desire for repair and had high expectations.Skin grafting is not an ideal repair plan due to the large differences in appearance and texture after the operation.For example,one patient in this group who accepted skin grafting due to congenital melanocytic nevus for 2 years required a second repair of the grafted skin.The adjacent flap is the best choice for facial repair because of its similar color and texture,and the normal area around the defect should be regarded as the primary donor site[7-8].When the facial skin defect is relatively large and the local flap is not sufficient to repair the wound,the best repair plan is to use facial soft tissue expansion technology to assist with the repair[9-10].The midface skin lesions are close to the eyes,nose,and upper lip.If the cheek skin is used as the donor site of the expanded flap,it is used as a random pattern flap.A long auxiliary incision is needed,which may cause displacements of the eye,nose,and lip.The appearance and texture of the forehead skin are similar to those of other facial areas.As an axial flap with sufficient blood supply,the forehead flap is easy to design and transfer,and hence it is the primary choice for nose reconstruction[3,11-13].The forehead flap is also the best choice for wound repair after the removal of midface skin lesions because only a minimal auxiliary incision in the midface is required[14-16].

Fig.2 A 18-year-old girl with scars due to isotope treatment of hemangioma

An original frontal flap is generally not sufficient to cover a large wound area.If a large forehead flap is cut,the donor site cannot be sutured in one stage.The skin soft tissue expansion technology can solve this problem well.However,with respect to wounds after the removal of midface skin lesions,only pure skin defects need to be repaired.The traditional paramedian frontal flap contains frontal muscle components and is too thick to repair pure skin defects,resulting in an unideal cosmetic effect after the repair.As such,the unideal method needs to be improved based on recent anatomical research[3,13,17].

In 1992,Shumrick conducted research on the vascular anatomy of the forehead flap[18]and suggested that the supratrochlear artery exited the orbit and traveled through the orbital septum in a position 1.7-2.2 cm lateral to the midline.The artery then traveled superomedially under the orbicularis oculi muscle and over the corrugator muscle at the medial portion of the eyebrow.The course continued vertically in the forehead 1.5-2.0 cm lateral to the midline.In the proximal two-thirds of the forehead,the supratrochlear vessel traveled in the muscle.In the distal third of the forehead,the supratrochlear vessel runs close to the dermis in the superficial layer.This provides an anatomical basis for the surgical method of removing the muscle from the distal third of the flap.Li Qingfeng’s team conducted further anatomical studies[3-4]and confirmed that a consistent cutaneous branch arose from a position 1.18 ± 0.36 cm distal to the supraorbital rim and 1.35 ± 0.34 cm lateral to the midline.The mean diameter of the branch was 0.81 ± 0.04 mm,and it was located at the medial portion of the eyebrow.The cutaneous branch moved superomedially and traveled subcutaneously throughout the course.The inferior two-thirds traveled under the fat tissue and over the frontalis muscle;the superior one-third traveled under the dermis and over the fat tissue.There were abundant traffic branches between the bilateral supratrochlear arteries and the cutaneous branch.The terminal branch of the supratrochlear artery was a muscular branch that traveled under the frontalis muscle.According to this anatomic study,the forehead flap can be cut in the subcutaneous plane at 1.7 cm above the supraorbital rim and nourished by the cutaneous branches of the supratrochlear artery,then cut into the submuscle approximately 1.7 cm above the supraorbital rim,and finally,cut the flap pedicle from the superficial layer of the periosteum.Thus,the main trunk of the supratrochlear artery can be preserved to ensure blood supply to the flap.In addition,abundant anastomoses between the two sides of the cutaneous branches of the supratrochlear region can ensure blood supply to the flap.Therefore,the donor position on the forehead flap can be designed according to the recipient area,without being confined to the range of the unilateral supratrochlear artery.This technique has been successfully applied to nasal reconstructions[3,4,13,17].

All the patients in our group only needed repair of the pure skin defect in the midface.For each patient,the flap was dissected from the distal part between the subcutaneous tissue and muscle from the distal point toward the pedicle side.When the point reached approximately 1.7 cm above the orbital rim,we went deeply and dissected between the muscles and periosteum.Thus,the flap was elevated with muscle in just the pedicle part,without including muscle in the middle and distal parts.We named this a stepped flap.As a superthin flap,its thickness was similar to that of normal skin in the midface.Therefore,no secondary flap-thinning surgery was required.Due to the excessive expansion of the forehead flap in one stage,the donor site was able to be sutured directly without tension,which reduced the scarring of the forehead.

In order to prevent the adverse contraction of the expanded flap on the surgical defect,it has been reported that the area of the expanded flap should be 20%-30% larger than that of the skin defect[2,11].In this study,we only increased the area by 10% when designing the flap,and based on follow-up results,there were no adverse effects.The difference was that we performed the secondstage operation more than 4 weeks after the completion of the expansion process,while the traditional method performed the second-stage operation 2 weeks after the completion of the expansion process.We believe that the extra 2 weeks of waiting is worthwhile.The expanded flap is more stable;moreover,the expanded flap does not require too much magnification and can be designed more accurately[14].This is particularly critical when the expanded flap is used for nasal reconstructions.

In our patients,the third-stage operation of flap pedicle division was performed 5 weeks after the second-stage operation.This is different from the conventional flap pedicle division time,which is 3 weeks.We observed an earlier nose reconstruction using a forehead flap,in which survival of the flap was not a problem when the flap division was performed 3 weeks after the flap transfer,but the color of the flap became slightly darker.The possible reason for this may be that the blood supply between the skin flap and the recipient area was not adequate 3 weeks after the flap transfer.Although the flap did not necrose after the pedicle division,the mild ischemia led to mild pigmentation in the later stage.In contrast,five weeks after the operation,sufficient blood supply was established between the expanded skin flap and the recipient area,and there was no ischemia after the pedicle was cut off in our group of patients.In combination with strict sun protection during the 6 months after surgery,no pigmentation of the flap was observed.

In this study,the wound of the flap pedicle was temporarily sealed using a skin graft of the midface skin lesion.We waited 5 weeks for the pedicle division,which was relatively long.If the pedicle is partially exposed by wrapping it with vaseline gauze,frequent dressing changes would be required,which is inconvenient in terms of wound management.The traditional method involves cutting the skin between the eyebrows to seal the wound of the expanded skin flap pedicle[3,4,13,17],but additional scars will be produced between the eyebrows.Wrapping the flap pedicle into a tube is another option,but this would increase the risk of venous reflux disturbance.From our cases,we believe that it is convenient to use the excised skin lesion to seal the wound of the flap pedicle,which will benefit wound management after the surgery.The skin lesion can be removed during the threestage operation,and the pedicle flap can be returned to the forehead between the eyebrows so that the eyebrow spacing returns to normal and the eyebrows on both sides are symmetrical.

CONCLUSION

Expanded forehead stepped flaps present an ideal option for repairing the wound after resection of a large skin lesion in the midface,as they boast multiple edges from a reliable blood supply,easiness to transfer,and wellmatched color,texture,and thickness to those of the surrounding skin of the face to no need for many auxiliary incisions.Hence,this technique merits consideration and promotion.

ETHICS DECLARATIONS

Ethics Approval and Consent to Participate

This study was approved by the Ethics Committee of Fujian Provincial Hospital.Written informed consent was obtained from all participants or parents/legal guardians of the children before study enrollment.

Consent for Publication

All the authors have consented to the publication of this article.

Competing Interests

The authors declare that they have no competing interests.The authors state that the views expressed in the article are their own and not the official position of the institution or funder.