60. Elastic canthopexy with three threads
KEYWORDS:elastic canthoplasty, canthoplasty, canthopexy, fox eyes, elastic thread, Elasticum suture, Jano needle
This young patient has round eyes and evident scleral exposure of familial origin. As often happens, the eyes are also asymmetrical, the right eye being slightly rounder than the left.
In elastic canthopexy, the preoperative drawing is important. A crow's foot is normally taken as a reference mark on both sides. If there are no crow's feet, the patient is asked to screw up her eyes and two symmetrical folds are chosen, one on either side. A line drawn along an expression wrinkle serves as a reference for the symmetry of traction.
The chosen line is first drawn up to the hairline then in the direction of the eye. The line extends to below the level of the lower eyelashes, approximately 8mm/10mm from the apex of the outer canthus. Once the two symmetrical vectors have been drawn, the bases of the isosceles traction triangles are drawn. The base is not less than 2.5 cm long in women and about 3 cm in men. If the patient wants the eyes to be raised, the base is moved upwards. The same is done if one eye is more horizontal than the other; on the side that needs to be lifted more, the base of the isosceles triangle is drawn 5 mm/10 mm higher. The aim is to make the patient's look as symmetrical as possible.
A dotted line is drawn with a dermographic pen, to indicate the pathway of the frontal branch of the facial nerve. The nerve runs from the lowest point of the earlobe to 1 cm from the tail of the eyebrow.
Local anesthesia is now carried out along the pathway of the threads. To a 10 ml vial of 2% Mepivacaine or 2% Lidocaine, we add ½ mg of Adrenaline. Once local anesthesia has been performed, we wait until hemostasis has time to occur.
A skin access is created with a slightly inclined 16G needle at the lower end of the base of the isosceles triangle. A Klemmer with a fine tip is used to enlarge the hole and to create a convenient site in depth, in which to house the knot or knots. As this hole will not be sutured, no scar will remain.
The Elasticum EP3.5 thread (Korpo SRL), mounted on a two-tipped Jano needle, is used. The needle is inserted deep into the dilated hole and then passes horizontally through the galea capitis, a fibrous tissue above the periosteum. It does not touch the periosteum. The Jano needle is partially extracted at the other end of the base of the isosceles triangle. The two-tipped needle is withdrawn until approximately 5mm of the posterior tip remains in the tissue. It is then rotated and travels in the direction of the canthus. In the first centimeter of this pathway, the needle again anchors the thread to the galea capitis. It then travels more superficially, immediately above the superficial fascia, below which the frontal branch of the facial nerve runs. It then follows a deeper pathway and partially emerges immediately below the level of the eyelashes, about 1 cm from the apex of the canthus. The two-tipped needle is withdrawn up to the 5th depth-mark, and the tip is angled in order to pass through the retinaculum, a fibrous structure that surrounds the eyelids. When the Jano needle makes contact with the retinaculum, this fibrous tissue resists penetration, and the eye visibly lengthens. If it does not lengthen, the tip of the Jano needle will need to be repositioned correctly. If the eye lengthens, the needle is passed through the retinaculum and continues in the direction of the access hole, where it is extracted. The two ends of the elastic thread are placed under tension and knotted. With a fine Klemmer, the operator presses the knot to the bottom of the hole.
The thread that forms the isosceles triangle is now implanted; traction will be exerted on the left eye and on the lateral tissues inside this triangle. After disinfecting the skin again, the operator creates an access hole at the lower end of the base of the triangle and then uses the tip of a fine Klemmer to enlarge and deepen the hole. The Jano needle penetrates at an angle and anchors the thread by passing through the galea capitis, the dense fibrous layer above the periosteum. Having created the base of the isosceles triangle, the operator partially withdraws the two-tipped needle with the aid of a hook. The elastic thread is pulled through and the needle is withdrawn until 5mm of the posterior tip remains in the tissues. The needle is then inclined and follows the preoperatively drawn line until it reaches the exit point below the level of the lower eyelashes, about 1 cm from the canthus. The Jano needle is partially withdrawn and the elastic thread is pulled through until the portion of the thread at the access point is seen to move. As always, a Klemmer is fixed to the end of the elastic thread.
The two-tipped needle is extracted up to the 5th depth-mark; it is then inclined in order to anchor the elastic thread to the retinaculum. This is the trickiest phase of implantation of the thread. The operator must find this fibrous tissue, which resists penetration by the needle. The operator should clearly see that the eye lengthens. Now that the eye is seen to lengthen, the Jano needle can continue along its pathway and exit through the entry hole. The two ends of the elastic thread are placed under tension and knotted. Using a fine Klemmer, the operator sinks the knot into the access hole.
The traction placed on the two eyes is evaluated. The right eye appears less elongated. Before surgery, the right eye exhibited greater scleral exposure and was shorter, rounder and larger than the left. We therefore decide to implant a third thread, in order to traction the right eye further and improve the symmetry of the eyes. Once the right side has been disinfected again, the operator deepens the hole with the Klemmer and administers a little more anesthetic along the pathway of the threads. The two-tipped needle is inserted into the dilated skin hole, slightly to one side of the previous implant. The needle penetrates the galea capitis, anchoring the elastic thread. The Jano needle continues along its pathway and partially emerges below the outer canthus. The needle then penetrates the retinaculum and continues along its pathway until it emerges completely from the access hole. The two ends of the elastic thread are placed under tension and knotted. The procedure is over. The access holes are not sutured; they are medicated with an antibiotic ointment twice a day. The eyes are now symmetrically elongated and equally narrow.
Capurro S. (2023). Elastic canthopexy with three threads. CRPUB Medical Video Journal. Elastic Plastic Surgery section. www.crpub.org.
Is it also possible to implant four elastic threads?
Yes, this can be done if the maximum traction effect is desired. Since no scars remain, it is also possible to intervene later, in order to improve traction or further change the inclination of the eyes.
Are preoperative photographs important?
Yes, we need to note the existing differences before the procedure, because they condition the result. If the eyes have a different inclination, for example, the isosceles triangle can be raised, so as to correct this asymmetry. If one eye is shorter and rounder, as in this patient, this is corrected by implanting a third elastic thread during the same procedure.
Does the two-tipped needle always travel at the same depth?
No. The thread is anchored to the galea capitis immediately above the periosteum, which it is preferable not to touch. When the two-tipped needle passes through the galea capitis and changes direction, it may anchor the thread for another 1 cm; its pathway then runs immediately above the superficial fascia. Once beyond the frontal branch of the facial nerve, the Jano needle travels at a greater depth and partially emerges below the eyelashes of the lower eyelid. Subsequently, its pathway continues to be subcutaneous. Only as it approaches the access hole can it penetrate more deeply, before emerging from the hole. Passage of the Jano needle from the extremity of the base of the triangle to the lower eyelid can be performed in two stages, especially in men.
How do you evaluate elongation?
By means of photographic documentation; if this has been done properly, it is not difficult to assess elongation. For example, the distance between the outer canthus and the lateral contour of the face can be assessed.
After canthopexy are the eyes longer and narrower?
Yes. In this way, they look younger and more attractive. With aging, eyes that were formerly almond-shaped become rounded because the ligaments slacken. Elastic canthopexy is therefore a rejuvenating procedure. It can also be performed in patients whose eyes are too close together. With elastic canthopexy this defect disappears. After canthopexy, there may be an excess of upper eyelid skin; this is easily corrected by means of excision. Canthopexy can also enlarge the eyes, though patients rarely request this.
How can the eyes be enlarged?
During upper blepharoplasty, the eyelid fat that prevents complete opening of the eyelid pulley can be removed; alternatively, a small medial flap can be excised from the inside of the eyelids, about 10 mm/11 mm from the edge of the eyelashes.
Is the result of elastic canthopexy permanent?
Yes, to date, elastic canthopexy has proved perfectly stable over time.
Can the elastic threads be removed?
Yes, but you need to make a small incision at the hairline where the knot is located
What advice can you give to anyone starting to perform this surgery?
Elastic canthopexy is easier than it looks. The elastic thread is first anchored to the galea capitis. The passage of the needle from the base of the triangle to below the outer canthus of the lower eyelid can then be performed in two stages, if we prefer. A little caution is required only when passing through the retinaculum.
The effectiveness of this step determines the lengthening of the eye // The effectiveness of this step is assessed by observing the lengthening of the eye. If there are other defects, such as evident eyelid pouches for example, but the patient only asks you to lengthen the eyes, do not operate. Indeed, this shows that the patient knows nothing about facial esthetics. Consequently, she will blame her imperfect appearance on the millimeter which, according to her, gives her an asymmetrical and less pleasant look. If, on the contrary, there are few pouches, lengthening the eyes can be ameliorative. Sometimes we perform lower transconjunctival blepharoplasty and elastic canthopexy during the same session, thereby solving two esthetic problems at the same time.
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