nsconjunctiva it Haitham Hadeed, DMD,a Vincent B. Ziccardi, Gary T. Patterson, DLMD,~ Pittsburgh, Pa. DEPARTMENT UNIVERSITY

OF SURGERY, HOSPITAL,

DIVISION

UNIVERSITY

OF ORAL

DDS,b George C. Sotereanos,

AND

MAXILLOFACIAL

SURGERY,

DMD,c

and

TRESBYTERIAN

OF PITTSBURGH

Multiple surgical approaches to the orbits with the use of the eyelids have been used. The orbital rim incision fell into disfavor because of esthetic considerations. A subciliary approach supplemented by the lateral brow incision is currently the most popular method of approach to the orbital rim. It provides adequate access to the orbit, but it is not without inherent complications, such as unfavorable scarring, ectropion, and entropion. This article describes an alternate approach to the orbit by means of a transconjunctival incision with lateral canthotomy. (OR~LSURGORALMEDOORALPATHOL 1992;73:526-30)

T he transconjunctival

approach was first used by Bourget” in 1928 for the removal of herniated orbital fat. Tenzel and Miller,2 in 1971, used this approach for repair of small blowout fractures, but it was Tessier,3 in 1973, who popularized the technique for orbital floor exploration and maxillary surgery in cases of congenital deformities and trauma. Numerous other authors4*6 have described isolated uses for this approach. Wray et a1.7 reported a comparison between the subciliary and transconjunctival approaches. In 1979 McCord* described a variant of the lateral canthotomy incision that enabled more exposure to the lateral orbital rim and zygoma. A lateral superior cantholysis was reported in 1985 by Nunery9 for the repair of trimalar fractures. SURGICAL ANATOMY OF THE EYELID

The eyelid can be conveniently divided into five separate planes: skin and subcutaneous tissues, orbicularis oculi muscle, orbital septum, lid retractors, conjunctiva and tarsi. The skin of the lids is the thinnest of the human body (Fig. 1). The tarsi form the skeletal structure of the lids. They are composed of fibrous tissue, sebaceous glands, and the meibomian aFormer chief resident. bResident and third year medical CAssociate Professor of Surgery. dAssistant Professor of Surgery.

7112134036

526

student.

Fig. 1. Sagittal view of orbital anatomy.

glands.;O There are approximately 25 meibomian glands in the upper lid and 20 in the lower. In addition, the fornix of the upper lid contains more than 40 accessory lacrimal glands, whereas the lower fornix has approximately 10. The tarsus itself is 5 mm wide

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Fig. 3. A, Upper lid traction suture, B, Desmore lower lid retractor, C, Protective eye lens in place, D, Incision outlined on patient. Fig. 2. Outline of proposed transconjunctival with lateral canthotomy incision.

vertically in the lower lid and 10 mm in the upper lid. However, the upper tarsus curves somewhat medially and laterally to a smaller vertical dimension.” The orbicularis oculi muscle is attached to the overlying skin. Tlhe eyelid itself is defined by three regions of the muscle: tarsal, septal, and orbital. The tarsal area is that portion over the tarsus plate, the septal area is over the orbital septum, and orbital region covers the circumference of the orbital bony rim.” Of anatomic importance to the transconjunctival incision is the lower lid furrow that demarcates the inferior extent of the tarsus. Medially, the tarsal components of the orbicularis muscle unite from the upper and lower lids to form the medial canthal tendon. Laterally, a tendlon is also formed in a similar fashion.” The conjunctiva is the nonkeratinized squamous epithelium that covers the internal lid and contains goblet cells and accessory lacrimal glands. The bulbar conjunctiva is that portion along the globe itself, whereas the palpebral portion lines the inner lid.‘O The lateral nasal and lacrimal arteries form a dense superficial network to supply most of the palpebral and bulbar conjunctiva. In addition, the anterior ciliary arteries supply some conjunctival branches. The two systems anastomose freely to provide for a profuse blood supply. l2 The orbital septum is a thin sheet of periosteum that arises from tlhe inferior and superior orbital rims. It lies below the orbicularis oris muscle and becomes confluent with the lid retractors. The lower lid retractor originates from the inferior rectus muscle, whereas the upper retractor originates from the levator muscle. The septum acts as a barrier between the

Fig. 4. Stevens scissors transecting lateral canthal attachment.

orbit and the lid and keeps the periorbital

fat within

the orbit. 11 This will become an important

landmark

for the dissection that is carried out in the bloodless zone between the septum and orbicularis muscle.13

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Hadeed et al.

ORAL

SCRG ORAL

MED ORAL

PATHOL

May 1992

Fig. 5. Sagittal view of incision placement and dissection plane.

SURGICAL

TECHNIQUE

Access for the transconjunctival incision is obtained with the use of a 5-O black silk traction suture. It is placed through the lid skin, tarsus, and palpebral conjunctiva. Once everted, the outline of the incision can be demarcated 1 mm from the junction between the palpebral and bulbar conjunctivae to the level of the plica semilunaris medially. The external skin of the lateral canthal tendon is demarcated in a natural skin crease approximately 5 mm in length (Fig. 2). Protective contact lenses should be placed with an ophthalmic lubricant for the duration of the procedure. With the use of a curved hemostat, the upper lid can be fixed to an open position. The assistant can manipulate the lower traction suture as the surgery dictates (Fig. 3). Hemostasis is achieved by injection of 1% lidocaine with 1:200,000 epinephrine with Wydase into the lateral canthal skin and preseptally in the subconjunctival plane of the lower lid. This will not only provide hemostasis but will also open the surgical plane for the dissection. The lateral canthotomy is made with a No. 15 scalpel or with tissue scissors down to the orbital rim in a medial-to-lateral direction (Fig. 4). The incision should be carried laterally at least 5 mm with the goal of transecting the upper and lower limbs of the lateral canthal tendon. Mobilization of the tendon is completed with a periosteal elevator. The lid retractor is used for gentle retraction of the lower lid and exposure of the fornix. With a No. 15 scalpel or scissors, the palpebral conjunctiva is incised approximately 1 to 1.5 mm above the fornix while the lower lid is everted. The conjunctiva is undermined above the lower lid retractors to approximately 0.5 mm below the inferior margin of the tarsal plate. Ophthalmic

tissue scissors are useful in the preseptal dissection just below the orbicularis muscle to the inferior orbital rim. This may be facilitated by placement of a small malleable retractor in the fornix and retraction of the orbital contents into the orbit itself. The periorbita is incised with a No. 15 scalpel, and subperiosteal dissection is carried out with a periosteal elevator (Fig. 5). At this juncture, the malleable could be used to retract the dissected periosteum and orbital contents to enable better visualization and protection of the globe. The lower two thirds of the medial orbit floor and lateral wall should now be exposed. The upper limb of the lateral canthal tendon may be dissected from the lateral orbital rim to gain access to the frontozygomatic suture region if indicated. If the exploration includes only the orbital floor, it is prudent to leave the upper canthal limb attached. A small relaxing incision could be made in the superior fornix laterally if additional exposure is needed. After completion of the bony work, the lateral canthal tendon should first be reapproximated. If only the lower limb was detached, it could be repositioned with either a 4-O polyglactin 9 10 (Vicryl) resorbable suture or a 5-O permanent polypropylene suture. Separation of the upper limb of the tendon will necessitate the placement of a small hole in the lateral bony rim, and reattachment of the complete tendon with a figureof-eight suture configuration. The orbital rim periosteum could be closed precisely to avoid a change in the position of the lower lid through its confluence with the orbital septum. However, we prefer to allow it to drape itself and reattach. A continuous running subconjunctival suture technique with 6-O fast-resorbing plain gut is used to close the palpebral conjunctiva.

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Fig. 6. Miniplate fixation of frontozyomatic suture obtained through the lateral canthotomy incision.

Fig. 7. Microplate fixation of comminutedinfraorbital and maxillary fractures.

The lateral canthal skin is closed with either 6-O nylon or gut sutures. DISCUSSION Based on a thorough understanding of the eyelid and orbital anatomy along with a precise surgical technique, the transconjunctival approach with lateral canthotomy offers a simple alternative to the subciliary technique. It provides the surgeonwith superb exposure to the orbital floor, infraorbital rim, lower two thirds of th,e medial wall, lateral wall, and lateral rim. This gives accessfor repair of zygomatic orbital complex fractures (Figs. 6 and 7), orbital floor exploration, and elevation of simple depressedzygomatic arch fractures. We have used this technique also for orbital reconstruction and repair of enophthalmos with autogenous bone grafts and cartilage or alloplastic materials such as orbital mesh (Fig. 8). Eyelid repositioning and horizontal shortening of a lagophthalmic eyelid by a lateral tarsal strip procedure with canthoplasty could be done concurrently. It is imperative to avoid inadvertent injury to the orbital septum during this procedure. That would allow herniation of the periorbital fat, which might interfere with vision or create an enophthalmos.6Some surgeonsdo not recommend suturing the orbital septum and periosteum t’o avoid the creation of an ectropion due to a sh’ortenedvertical lid height, or entropion due to lid inversion. 6, l3 Closure of the conjunctiva is useful to ,avoid both of these problems, and is the method we -prefer. With orbital grafting procedures, it may be advisable to use a few septal tacking sutures.13Overzealous retraction or careless dissection may lead to tears in the skin of the lower lid. This is avoided by closeattention to the operative field and surgical technique.6 Exposure with this incision is

Fig. 8. Orbital floor reconstructionwith Vitallium meshwork. somewhat more technique-sensitive and requires strong traction that may result in more postoperative swelling. This has produced no long-term sequelae.14 SUMMARY The lateral canthotomy transconjunctival approach to the zygomatic orbital complex provides the surgeon with an excellent exposure to the bony orbit without some of the complications associatedwith the transcutaneous approach. Surgeons who infrequently perform orbital surgery may elect not to use this technique becauseof the added complexity of the surgical dissection and the meticulous closure necessary to avoid complications. Avoidance of scarring is the goal of every facial surgeon. With this approach, the cutaneous brow and subciliary incisions are totally avoided. The lateral canthal incision healswell in a few weekswithout any objectionable scarring.

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ORALSURG

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ORALPATHOL

May 1992 REFERENCES Bourget J. Notre traitment chirforgicai de “poches” sons less san cicatrice. Arch Graefes Belg chir 1928;3 1:133. Tenzel RR, Miller GR. Orbital blowout fracture repair, conjunctival approach. Am J Ophthalmol 1971;71:1141-2. Tessier P. The conjunctival approach to the orbital floor and maxilla in congenital malformation and trauma. J Maxillofac Surg 1973;1:3. 4. Converse JM: Firman F, Wood-Smith DA, Friedland JA, The conjunctival approach in orbital fractures. Plast Reconstr Surg 1973;52:656. 5. Lynch D, Lamp JC, Royester HP. The conjunctival approach for exploration of the orbital floor. Plast Reconstr Surg 1974;54:153. 6. Habal MB, Chaset RB. Infraciliary transconjunctival approach to the orbital floor for correction of traumatic lesions. Surg Gynecol Obstet 1974;139:420-2. Wray RC, Holtman B, Ribaudo JM, Keiter J, Weeks PM. A comparison of conjunctival and subciliary incisions for orbital fractures. Br J Plast Surg 1977;30:142. McCord CD, Moses JL. Exposure of the inferior orbit with fornix incision and lateral canthotomy. Ophthalmic Surg 1979;10:53-63. Nunery WR. Lateral canthal approach to repair of trimalar fractures of the zygoma. Ophthal Plast Reconstr Surg 1985;1:75-83.

10. Waltman SR, Keates RH, Hoyt CS, Freuh BR, Herschler J, Carrol DM. Surgery of the eye, New York: Churchill Livingston, 1988:417-9. 11. Spaeth GL. Ophthalmic surgery: principles and practice, Philadelphia: WB Saunders, 1990:53 t-4. 12. Peyman GA, Saunders DR, Goldberg MF. Principles and practice of ophthalmology, Philadelphia: WB Saunders, 1980:955-6. 13. Habel MB. Experience in the application of the transconjunctival route for surgical exposure in the orbital region. Surg Gynecol Obstet 1976;143:437-9. 14. Manson PN. Single eyelid incision for exposure of the zygomatic bone and orbital reconstruction. Plast Reconstr Surg 1987;79:120-6. Reprint

requests:

Vincent B. Ziccardi, DDS Department of Surgery Division of Oral and Maxillofaciai Presbyterian University Hospital 686 Scaife Hall 3550 Terrace St. Pittsburgh, PA 15261

Surgery

Lateral canthotomy transconjunctival approach to the orbit.

Multiple surgical approaches to the orbits with the use of the eyelids have been used. The orbital rim incision fell into disfavor because of esthetic...
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