Periorbital Incisons

PERIORBITAL INCISIONS

  

                Types

•     Supraorbital eyebrow

•     Lower eyelid incision

•     Transconjunctival

•     Upper eyelid incision

Principle of incision placement

•     Avoid important neurovascular structures

•     Use as long an incision as necessary

•     Place incision perpendicular to surface of non-hair bearing skin

•     Place incision in line of minimal tension

•     Seek for other favorable sites for incision placement if minimal tension not available

Concern

•     Primary factor in incision placement is not surgical convenience but facial esthetics.

•     A second factor that differentiates incision placement on the face from that anywhere else on the body is the presence of the muscles and nerve (cranial nerve VII) of facial expression

•     A third factor in facial incision placement is the presence of many important sensory nerves exiting the skull at multiple locations.

•     Other important factors are the age of the patient, existing unique anatomy, and patient expectations.

Various periorbital incisions/approaches

•    Supraorbital eyebrow incision

•    Lower eyelid incision

•    Transconjunctival incision

•    Upper eyelid incision

•    Infraorbital incision

•    Zygomatic arch incision

•    Transverse nasal incision

•    Vertical incision

•    Medial orbital incision

Supraorbital eyebrow incision

Supraorbital eyebrow incision is used to gain access to the superolateral orbital rim. No important neurovascular structures are involved in this approach, and it gives simple and rapid access to the frontozygomatic area. If the incision is made almost entirely within the confines of the eyebrow, the scar is usually imperceptible.

Unfortunately, in individual who has no eyebrows extending
laterally and inferiorly along the orbital margin, this approach is undesirable. The main disadvantage of the approach is extremely limited access.

Technique

•    Protection: Protection of the cornea during operative procedures around the orbit is an excellent precautionary measure. If one is operating on the skin side of the eyelids to approach the orbital rim and/or orbital floor, a temporary tarsorrhaphy or scleral shell may be used after application of a bland eye ointment. These are simply removed at the completion of the operation.
Identification of and marking incision line is done so as to guide the surgeon in pre-determined course of incision. Incision line is marked before vasoconstriction as tissues may distort after infiltration and therefore a perceptible crease may disappear after injection.

•    Vasoconstriction: LA with vasoconstrictor

•    Skin Incision: Eyebrow is not shaved, skin straddled using 2 fingers and 2 cm incision is made. Incision should be parallel to hair of eyebrow and to the depth of periosteum in one stroke. Incision should not be extended inferiorly along orbital rim as incision crosses the line of resting skin tension, making it more conspicuous. If more inferior exposure is required, the incision should extend laterally into a crow's foot wrinkle at least 6 mm above the level of the lateral canthus.

•    Periosteal incision: After undermining in the supraperiosteal plane, the skin is retracted until it is over the area of interest. Another incision through the periosteum completes the sharp dissection.

•    Subperiosteal Dissection of Lateral Orbital Rim and Lateral Orbit: Two sharp periosteal elevators are used to expose the lateral orbital rim on the lateral, medial (intraorbital), and, if necessary, posterior (temporal) surfaces. Wide undermining of the skin and periosteum allows the tissues to be retracted inferiorly, providing better access to the lower portions of the lateral orbital rim. If one stays in the subperiosteal space, there is virtually no chance of damaging structures.

•    Closure: The incision is closed in two layers, the periosteum and the skin.

Lower eyelid approach

In Lower eyelid approach, it is approached through the external side of the lower eyelid as it offers superb exposure to the inferior orbital rim, the floor of the orbit, the lateral orbit, and the inferior portion of the medial orbital rim and wall.

These approaches are given many names based primarily on the position of the skin incision in the lower eyelid (e.g., blepharoplasty, Subciliary, lower lid, subtarsal, infraorbital).

Here, the detailed description is given for subciliary incision.

The skin incision is made just below the eyelashes. Subsequent to the skin incision there are three optional pathways for the dissection down to the orbital rim:
        Subcutaneous
        Deep to the orbicularis oculi muscle
        Step dissection or layered Converse technique

Subcutaneous: Dissection is between the skin and the muscle until the orbital rim is reached, at which point another incision through muscle and periosteum is made to the bone.
Disadvantage:  It leaves an extremely thin skin flap.
                        Buttonhole dehiscence
                        Darkening of skin after healing

Deep to the orbicularis oculi muscle: Incision is through muscle at the same level as the skin incision and dissecting down just anterior to the orbital septum to the orbital rim.
Disadvantage: thin orbital septum can be easily violated, causing periorbital fat to herniate into the wound

Step dissection or layered Converse technique: Combination of above two in which subcutaneous dissection toward the rim proceeds for a few millimeters followed by incision through the muscle at a lower level, producing a step-incision, then following the orbital septum to the rim. It avoids the disadvantages of the other mentioned technique.

Technique

Protection of cornea as like in previous method.

Incision marking is done and vasoconstrictor is applied.

One should carefully evaluate the skin creases & direction of skin crease. Commonly, the crease tails off inferiorly as it extends laterally. This incision, however, should not change direction from the original skin crease or a noticeable scar will result.

The incision is approximately 2 mm below the eyelashes
and can be extended laterally as necessary & is made through skin only.

The incision for a subciliary approach is made approximately 2 mm inferior to the lashes, along the entire length of the lid.

The incision may be extended laterally approximately 1 to 1.5 cm in a natural crease if more exposure is necessary.

The depth of the initial incision is through the skin only. One should see the underlying muscle when the skin in incised completely.

Subcutaneous dissection toward the inferior orbital rim proceeds for a few millimeters using sharp dissection with a scalpel or scissors. Approx., 4-6mm subcutaneous dissection is enough.

For Sub-Orbicularis Dissection Scissors with slightly blunted tips are used to dissect through the orbicularis oculi muscle (by spreading in the direction of the muscle) to the periosteum overlying the lateral orbital rim. The muscle is dissected initially over the bony rim because the depth is much easier to determine here than over the orbital septum.

Supraperiosteal dissection continues in this submuscular plane inferiorly along the lateral rim, over the anterior edge of the infraorbital rim, and finally, the scissors are used to spread upward in this pocket into the lower eyelid. The convexity of curved scissor is outward.

Incision between Pretarsal and Preseptal Portions of Orbicularis Oculi Muscle: An attachment of orbicularis oculi muscle will remain, extending from the tarsal plane to the skin muscle flap, which was just elevated from the orbital septum. This muscle is now incised with scissors inferior to the level of the initial skin incision.

Periosteal Incision: Once the skin/muscle flap of tissue is elevated from the lower eyelid, it can be retracted inferiorly, extending below the inferior orbital rim. One should see the tarsal plate above with the pretarsal portion of orbicularis oculi still attached, and the orbital septum below extending to the infraorbital rim.

An incision through the periosteum on the anterior surface of the maxilla and zygoma, 2 to 3 mm below or lateral the orbital rim, can be made with a scalpel.

The incision through the periosteum at this level avoids the insertion of the orbital septum along the orbital margin. The infraorbital nerve is approximately 5 to 7 mm inferior to the orbital rim and should be avoided when the periosteal incision is made.

Subperiosteal Dissection of Anterior Maxilla and/or Orbit: The sharp end of a periosteal elevator is pulled across the full length of the periosteal incision to separate the incised edges. Periosteal elevators are then used to strip the periosteum from the underlying osseous skeleton, both along the anterior surface of the maxilla and zygoma and inside the orbit.

The inferior orbital rim is superior to the orbital floor just behind it.

After the periosteum of the infraorbital rim is elevated, the elevator is positioned vertically, stripping inferiorly as it proceeds posteriorly for the first centimeter or so.

Closure: Closure is usually performed in two layers - the periosteum and skin. Suturing of the orbicularis oculi muscle is difficult and of little value. Interrupted or running ressorbable periosteal sutures, such as 5-0 catgut, ensure that the soft tissue stripped from the anterior surface of the maxilla and zygoma are repositioned. A 6-0 nonresorbable or fast-resorbing suture is then run along the skin margin.

Transconjunctival Approach

Transconjunctival approach is a popular approach for exposure of the orbital floor and infraorbital rim. There are two techniques, preseptal and retroseptal techniques

The retroseptal approach is more direct than the preseptal approach and easier to perform. The periorbital fat may be encountered during the retroseptal approach, but this is of little concern and causes no ill effects. A lateral canthotomy is frequently used with transconjunctival incisions for improved lateral exposure.

The main advantage of transconjunctival approaches is that they produce excellent cosmetic results because the scar is hidden in the conjunctiva. If a canthotomy is performed in conjunction with the approach, the only visible scar is the lateral extension, which heals with an inconspicuous scar. Another advantage is that these techniques are rapid, and no skin or muscle dissection is necessary.

One disadvantage of the transconjunctival approach is that the medial extent of the incision is limited by the lacrimal drainage system.

Technique

Protection of globe: Protection of the cornea during operative procedures around the orbit is beneficial. Because tarsorrhaphy is precluded with this approach, a corneal shield may be placed to protect the globe.

Vasoconstriction: A vasoconstrictor can be injected under the conjunctiva to aid in hemostasis. A minimal amount is necessary. Additional solution is infiltrated in the area of the lateral canthotomy.

Traction Sutures in Lower Eyelid: The lower eyelid is everted with fine forceps and two or three traction sutures are placed through the eyelid. These should be placed straight through the eyelid, from palpebral conjunctiva to skin, approximately 4 to 5 mm below the lid margin to ensure that the tarsal plate is included in the suture.

Lateral Canthotomy and Inferior Cantholysis: If a lateral canthotomy is used, the approach begins with it. One tip of pointed scissors is placed inside the palpebral fissure, extending laterally to the depth of the underlying lateral orbital rim (approximately 7 to 10 mm). The scissors are used to cut horizontally through the lateral palpebral fissure. The structure cut in the horizontal plane are skin, orbicularis muscle, orbital septum, lateral canthal tendon, and conjunctiva. The traction sutures are used to evert the lower lid.
The lower lid is still tethered to the lateral orbital rim by the inferior limb of the lateral canthal tendon and is isolated by retraction and incised by scissor.

To perform the cantholysis, the scissors will need to be positioned with a vertical orientation. Once the cantholysis is complete, an immediate release of the lower lid from the lateral orbital rim is noted.

Transconjunctival Incision: Once the lower lid is everted, the position of the lower tarsal plate through the conjunctiva is noted. Blunt-tipped pointed scissors are used to dissect through the small incision through the conjunctiva made during the lateral canthotomy, inferiorly toward the infraorbital rim. The traction sutures are used to evert the lower eyelid during the dissection. Spread the scissors to clear a pocket just posterior to the orbital septum, ending just posterior to the orbital rim

Scissors are used to incise the conjunctiva and lower lid retractors midway between the inferior margin of the tarsal plate and the inferior conjunctival fornix. The incision should not extend farther medially than the lacrimal punctum.

Periosteal Incision: With retraction of the orbital contents and the lower lid, using suitable retractors, a scalpel is used to incise the periorbita, taking care to stay lateral to the lacrimal sac. The incision through the periorbita is just posterior to the orbital rim when the retroseptal approach is used.

Subperiosteal Orbital Dissection: Periosteal elevators are used to strip the periosteum over the orbital rim and anterior surface of the maxilla and zygoma, and orbital floor. A broad malleable retractor should be placed as soon as feasible to protect the orbit and to confine any herniating periorbital fat.

Closure: Periosteal sutures are not absolutely necessary, but if exposure permits, the can be placed. The conjunctiva is closed with a running 6-0 chromic gut suture. The ends of the suture may be buried. No attempt is made to reapproximate the lower lid retractors because they are intimately in contact with the conjunctiva and will be adequately repositioned with closure of that layer. Once the conjunctiva is closed, an inferior canthopexy is performed. A 4-0 polyglactin or other long lasting suture is used to reattach the lateral portion of the inferior tarsal plate to the superior portion of the canthal tendon and surrounding tissues.

The bulk of the lateral canthal tendon attaches to the orbital tubercle, 3 to 4 mm posterior to the orbital margin. Following canthotomy, the superior limb of the canthal tendon is still attached to the orbital tubercle. It is important to place the suture as deep behind the orbital rim as possible to adapt the lower eyelid to the globe. If the suture is not properly placed, the eyelid will not contact the globe laterally, giving an unnatural appearance.

Finally, subcutaneous sutures and 6-0 skin suture are placed along the horizontal lateral canthotomy.

Upper eyelid incision

The upper eyelid approach to the superolateral orbital rim

•     Upper blepharoplasty

•     Upper eyelid crease

•     Supratarsal fold approach.

The advantage of this approach is the inconspicuous scar it
creates.

Technique

Protection of globe: a temporary tarsorrhaphy or scleral shell may be used after application of a bland eye ointment. These are simply removed at the completion of the operation.

Identification of and marking Incision Line: Careful evaluation of tissues and if tissues are edematous, the skin surrounding the opposite orbit can be used to obtain an appreciation for the direction of creases. The incision should begin at least 10 mm superior
to the upper lid margin and be 6 mm above the lateral canthus as it extends laterally. The incision line is marked before infiltration of a vasoconstrictor.

Vasoconstriction
Local anesthesia with a vasoconstrictor is injected under the eyelid skin and orbicularis oculi muscle along the incision line. Additional vasoconstrictor solution is injected supraperiosteally in the area to be surgically exposed.

Skin Incision
The incision is through both skin and orbicularis oculi muscle. The vasculature of the muscle maintains the viability of the skin when they are elevated together, and this leads to excellent healing.

Undermining of Skin-Muscle Flap
A skin-muscle flap is developed superiorly, laterally, and if necessary, medially, using scissor dissection in a plane deep to the orbicularis oculi muscle. The dissection is carried over the orbital rim, exposing the periosteum.

Periosteal Incision
The skin-muscle flap is retracted until the area of interest is exposed. The periosteum is divided 2 to 3 mm posterior to the orbital rim with a scalpel.

Subperiosteal Dissection of Lateral Orbital Rim and Lateral Orbit
Periosteal elevators are used to perform subperiosteal dissection of the orbit and orbital rims. One must be aware of the lacrimal fossa, a deep concavity in the superolateral orbit. When reflecting periosteum from the lateral orbital rim into the orbit, one must turn the periosteal elevator so that it extends almost directly laterally inside the orbital rim. If the periosteum is violated, the lacrimal gland will herniate through the periosteum into the surgical field.

Closure
The wound is closed in two layers, periosteum and skin/muscle.

References

Surgical approaches to facial skeleton: Edward Ellis II, Michale F Zide

AO Foundation (www2.aofoundation.com)

Textbook of oral and maxillofacial surgery: Neelima Anil Malik