Correction of orbital implant exposure using a supra-brow island flap pedicled with orbicularis oculi muscle

Purpose To describe our experience of the supra-brow island flap pedicled with orbicularis oculi muscle technique for correcting orbit implant exposure. Materials and methods This retrospective study reviewed 32 patients that underwent orbit implant exposure surgery using a supra-brow island flap pedicled with orbicularis oculi muscle. All data were reviewed from patients in Eye & ENT Hospital of Fudan University, Shanghai during January 2018 to July 2020. The patient demographics, the original etiology, surgical procedures, implant types, and follow-up interval were recorded. The primary outcome was the long-term coverage of the supra-brow island flap pedicled with orbicularis oculi muscle, and the post-surgical complications and management were secondary outcomes. Results 28 eyes of 28 patients had functional results and satisfactory cosmetic outcomes at final follow up(range, 9–29 months). Among the other 4 patients, the recurrence of exposure was recorded during the follow-up, two of these patients successfully underwent dermis fat grafts(DFGs), one recovered after conservative treatment, and one refused treatment. Conclusions The supra-brow island flap pedicled with orbicularis oculi muscle is a technique available to manage orbital implant exposure when other simpler and more direct techniques have been tried and failed. Precis A new flap for orbital implant exposure


Introduction
The orbital implantation and artificial eye are clinically used to restore the orbital volume after enucleation or evisceration surgery, and promote the socket appearance. Implant exposure is a common complication after orbital implant implantation surgery. [1][2][3][4][5][6] Risks factors leading to implant exposure include inadequate suture or poor wound closure technology, inflammatory or mechanical stimulation from rough spicules of implants, pressure by prosthesis on conjunctiva, insufficient implant vascularization and subsequent tissue breakdown. 3 It has been reported that the wrapping of implants is associated with low exposure rate. 4 If left untreated, it may lead to more serious complications, such as implant infection, which is reported to be the most serious complication after orbital implantation surgery. However, there is also studies show that unwrapped implants may be associated with low exposure rate, 5 and different research properties and follow-up time may lead to different results.
Management of orbital implant exposure includes conservative treatment and surgical intervention. Conservative management includes local administration of steroids-containing or free antibiotics, with self-healing for small exposure. If the implant exposure does not resolve within 2 months, it is recommended to use the graft for surgical intervention, act as a scaffold to allow the conjunctival epithelium ingrowth from the edge. Various grafts and flaps, include scleral grafts, dermal fat grafts (DFGs), conjunctival grafts and amniotic membrane have been proposed for implant exposure coverage. [6][7][8][9][10] Studies have reported the use of orbicularis oculi muscle flap for eyelid reconstruction. 11,12 This article reports the technique of the supra-brow island flap pedicled with the orbicularis oculi muscle for management of orbital implant exposure with a variety of implant types.

Patients and methods
This is a single-center, retrospective observational case series study to evaluate the implant exposure repair with supra-brow island flap pedicled with the orbicularis oculi muscle. We collected the medical records of 32 patients(32 eyes) with orbital implant exposure who were admitted to the Eye＆ENT Hospital of Fudan University, Shanghai, China, from January 2018 to July 2020. This study was approved by the Human Ethics Review Committee of Eye＆ENT Hospital of Fudan University and in accordance with the tenets of the Declaration of Helsinki. The parents or guardians of study participants (who were minors at the time of the study) gave written consent to participate in the study, the publication of this article, and accompanying images. Written informed consent was also obtained from the patient to publish the figures of face photographs. Our patients underwent surgery with the same oculoplastic surgeon (Dr. Ye), and follow-up examinations were arranged after operation.

Surgical techniques
Under general anesthesia, the conjunctiva around the exposed area and the edge of the Tenon's capsule were released and lifted to prepare the implant bed, as shown in Figure 1A. The implant was then smoothed with a drill to make it less convex in the exposed area and a continuous infusion of antibiotic solution was used to exclude infection. The exposed area of the implant and the area required for the supra-brow island flap to fill the defect were measured and marked. The supra-brow flap was usually no more than 20mm*10mm in size, as shown in Figure 1B, F. The incision near the eyebrow should be parallel to the edge of the eyebrow. To avoid damaging the hair follicles of the eyebrow, the medial side of the flap should not exceed the medial side of the eyebrow. The skin was cut along the marker line and deep into the fat tissue.
As shown in Figure 1C, G, an flap pedicled with orbicularis oculi muscle was dissected from nasal to temporal side，the orbicularis oculi muscle extended to the tip of the flap. The island flap was composed of skin, subcutaneous tissue and superficial orbicularis oculi muscle. Figure 1. (a) Careful separation was performed along the orbital implant and the conjunctival fascia, examination of the exposed area, assessment of the exposed area and the size of the flap required for transfer. (b, f) Island flap design. The incision was close to the eyebrow and parallel to the hair follicle. To avoid damaging the eyebrow hair follicle, the medial extent of the flap should not extend the inner side of eyebrow. (c, g) Anatomical view of the flap above the muscular layer from nasal to lateral end. (d, h, i) A tunnel was made between the orbicularis muscle and the orbital periosteum, and the flap was transferred into the exposed area of the implant through the tunnel in the lateral-superior fornix of the socket, with the flap skin surface facing outside. (e, j) The surrounding conjunctiva was loaded onto the flap and sutured with flap edge and incision suture on the supra-brow skin.
By tunneling the space between the orbicularis muscle and the orbital periosteum, and through the lateral-superior fornix of conjunctival sac, the flap was applied to the exposed implantation area with no tension, with the skin surface facing outward. Placing the surrounding conjunctiva over the flap, and the flap was sutured with conjunctiva edge using 5-0 absorbable suture (VICRYL, Ethicon) as shown in Figure 1D, H, I.
The eyebrows were fixed to the periosteum with 5-0 absorbable sutures. Fix the desired eyebrow position and close the incision. As shown in Figure 1E, J, the subcutaneous tissue was closed with 5-0 absorbable sutures and the skin was closed with 6-0 nylon (PROLENE, Ethicon). At the end of the surgery, a conformer was placed in the conjunctival sac and suture of the palpebral fissure was performed. Antibiotic eye ointment was applied to the conjunctival sac, and gauze was used for pressure dressing for three days.

Data analysis
All statistical analyses were performed using the statistical software package (SPSS, version13.0; SPSS Inc. Chicago, IL).

Results
Demographic and clinical data are presented in Table 1. The repair of the supra-brow island flap was successfully performed in 28 eyes (87.5%), and no re-exposure and other serious complications were detected during the follow-up. Each patient was successfully fitted with a prosthesis.
However, during follow-up, implant re-exposure occurred in 4 eyes (12.5%) and DFGs repair was performed in 2 patients. Table 2 shows the management of re-exposure cases: Case 1 had a porous polyethylene implant, and we used supra-brow island flap pedicled orbicularis oculi muscle to manage implant exposure; however, re-exposure resulted in medial and inferior flap defects that did not heal after 2 months of treatment with topical lubricants and antibiotics. The flap in case 2 also had a medial and inferior defect that failed to heal spontaneously after several weeks. In both cases, DFGs were successfully applied for repair.
Case 3 had a small defect in the medial and underside of the flap that spontaneously healed after conservative treatment with local lubricants and antibiotics.
In case 4, the HA implant was re-exposed with a central flap defect, however, the patient refused to repair.

Patient 1
A 5-year-old female received a porous polyethylene implant after evisceration. A small exposed area of the implant was observed 4 months after surgery. We covered the exposed area with a scleral patch and placed the conjunctiva on scleral patch, which melted 1 month later. Then, the exposed area was covered with a supra-brow island flap pedicled with the orbicularis oculi muscle. The treatment was successful, as shown in Figure 2.

Patient 2
An 8-year-old female presented with enucleation of a retinoblastoma in her left eye. She was referred for exposure found during follow-up. As shown in Figure 3, we successfully managed the exposure with a supra-brow island flap pedicled with the orbicularis oculi muscle, the patient was able to wear the prothesis and cosmetic satisfaction was improved.

Discussion
Here, we examined 32 cases of orbital implant exposure treated with a supra-brow island flap pedicled with the orbicularis oculi muscle. Exposure was successfully repaired without serious complications in 28 cases, while a second management was required in 4 orbital implant re-exposure patients. To our knowledge, this is the first report of this flap to manage exposed orbital implant, an interesting alternative technique for the transplantation of an autogenous vascularized flap from the ipsilateral supra-brow area. Autogenous orbicularis oculi muscle flap grafts have been described as important role in eyelid repair and reconstruction, like the management of eyelid diseases: ectropion, lagophthalmos, full-thickness eyelid defects. [11][12][13] The orbicularis oculi muscle is distributed around the palpebral fissure, which makes it easy to transfer the flap pedicled with it to the adjacent area of defect, in addition, its rich blood supply ensures the survival of flap and motility.
Factors such as infection, wound healing problems, previous history of radiation, or inappropriate surgery procedures may increase the incidence of orbital implant exposure. 14 Clinically, in order to reduce this complication, the size of the implant should be properly evaluated prior to implantation, and the implant should be placed in an appropriate position, the tenon sac and conjunctiva on the surface of implant should be adequately sutured without tension. [1][2][3] Repair of an exposed implant is needed, especially when defect is large, to prevent persist infection and implant extrusion.
The management of implant exposure depends on a variety of factors, including the size of the defect, the presence of infection, and vascularization of the implant. For small exposure less than 4mm 2 , spontaneously healing of exposure is sometimes observed. 15,16 However, for larger exposure, observation is ineffective in most cases, so surgical treatment is recommended if not resolve in 8 weeks under conservative treatment. 3,17 Besides, infected orbital implants with well-vascularization can be rescued by antibiotics, while implants with poor vascularization should be replaced by surgery. 14 Clinically, tissue grafts are often used to repair exposed implants. Previous studies have reported to repair orbital implant exposure by using banked sclera, frontal periosteum, amniotic membrane, müller muscle flap, or biosynthetic materials. 17,18 A good blood supply is essential for the survival of the graft, and for the supra-brow island flap pedicled with the orbicularis muscle, this was achieved with a good blood supply by the pedicled orbicularis muscle.
It is well known that autologous tissue is generally readily obtained, causes less inflammation, and has no risk of disease transmission. 19 This island flap is an autograft of the ipsilateral supra-brow flap, and the donor site is easy to access and transfer. Most ophthalmologists have a good understanding of the anatomy of this area, making this surgical technique safe and feasible.
Final coverage failure or persistent infection is the main risk factor for treatment of orbital implants exposure, 19,20 with removal of the implant and autologous DFGs seemingly favored. 21 As in our study, none of our implants were infected，the original implant does not need to be removed and the surgical time was significantly shortened.   The main disadvantage of the supra-brow flap technique is the upper eyebrow scar. There are also risks associated with odor, excessive secretion, possible hair growth, ptosis, shortening of the conjunctival fornix, eyelid retraction and bleeding. In this study, sebaceous gland secretion gradually decreased after 3 months. In subjects with longstanding secretions and odors, symptoms were alleviated by administration of antibiotic eye drops and irrigation of fornix with normal saline (2-4 times daily). Fortunately, our subjects did not experience serious complications. Further studies are needed to compare with other surgical techniques to evaluate the application of the flap for treatment of orbital implant exposure.
Previous studies have reported higher exposure rate of pediatric implants than adults. 22 Retinoblastoma is the main cause of orbital surgery in pediatric patients. 23 This study included 18 patients with retinoblastoma, has previously explored the use of DFGs, re-suture, and donor sclera to repair the exposed implants. [22][23][24] Based on the results of our present study, this flap is also an appropriate choice for the repair of pediatric orbital implant exposure.
The sample size of this study was relatively small, the retrospective nature and follow-up time was limited. The risk of re-exposure is lifetime, with the possibility of late re-exposure and the possibility of subsequent additional surgery, such as socket surgery, so larger case series and longer follow-up would help to assess the long-term efficacy of this procedure.
In summary, we reported a surgical technique for repairing orbital implant exposure with a supra-brow island flap pedicled with orbicularis muscle. When other attempts at simpler, more direct techniques failed, we recommended the use of this flap for orbital implants with exposures greater than 4mm 2 . It is a reliable surgical technique to establish a good-vascularized environment and provide a high success rate for wrapping materials, which may work as a good strategy to manage orbital implant exposure.

Author contributions
All authors contributed to the study's conception and design. Conceive and design experiment: Ye Xinhai. Experiment performed: Zhang Zhenzhen. Data analysis: Zhang Zhenzhen. Contributing reagents/materials/analytical tools: Ye Xinhai. Author: Zhang Zhenzhen.

Availability of data and materials
All data generated or analyzed during this study are included in this article.

Consent to participate and publication
All subjects provided informed consent to participate in the study. Written informed consent was obtained from all participants prior to examinations and procedures. All patients or their guardians specifically agreed to publish their data and images.

Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the Science and Technology Development Fund project of Shanghai Science and Technology Commission(Grant No. 18411969300; Xinhai Ye).

Ethics committee statements
This study was approved by the Ethics Committee of Eye＆ENT Hospital, Fudan`University, Shanghai, China. This study was performed in accordance with the Declaration of Helsinki Declaration of 1964, and its later amendments.