A Standardized Surgical Technique for Tessier Medial Transnasal Canthopexy

Summary

Medial canthopexy allows correction of the position and fixation of the medial canthal tendon. Due to the technical difficulties of this procedure, there is a need for a detailed protocol for educational purposes. Here, we describe a standardized reproducible technique for bilateral medial transnasal canthopexy by an orbitonasal approach.

Abstract

Medial canthopexy is a surgical technique that allows correction of the position of the medial canthus, corresponding to the medial angle of the palpebral fissure. Abnormal position of the medial canthus is observed in the case of telecanthus (excessive intercanthal distance) or medial canthal dystopia (displaced medial canthus), encountered in congenital craniofacial malformations or after craniofacial trauma or tumoral resection that affects the orbits.

Correcting the position of the medial canthus is a challenge for the training surgeon, due to the difficulty of the techniques. Medial transnasal canthopexy aims to reposition and fix the medial canthal tendon contralaterally with wires. This technique is difficult to realize, due to the need for successive transnasal passages of several wires with limited surgical access, and the small size and fragility of the medial canthal tendon. A learning curve is thus required.

To date, literature is scarce concerning the description of the technique for medial transnasal canthopexy, and several variations of the technique are described. We aimed to describe a standardized, reproducible technique for bilateral medial transnasal canthopexy by an orbitonasal approach, based on Paul Tessier's technique, which our team has been experienced with for several years.

Introduction

An abnormal position of the medial canthus is observed in the case of telecanthus, which is defined by an excessive intercanthal distance or medial canthal dystopia, corresponding to a displaced medial canthus. Telecanthus can be uni- or bilateral, resulting in rounding of the palpebral fissure as well as flattening of the caruncle. This may lead to functional consequences such as epiphora or pseudoptosis (false sensation of eyelid drooping), as well as aesthetic consequences. Telecanthus and/or canthal medial dystopia are encountered in various congenital craniofacial malformations (such as craniosynostosis syndromes, orodigitofacial dysostosis, Waardenburg syndrome, etc) or after craniofacial trauma or tumoral resection that affects the orbits. In these cases, medial canthal tendon repositioning is required to correct morphological and functional consequences. Medial canthopexy is a surgical technique that allows correction of the position of the medial canthal tendon, corresponding to the medial angle of the palpebral fissure, in a stable and permanent manner.

Anatomically, the medial canthal ligament contains two bundles: an anterior bundle, which is stronger and thicker, inserting anterior to the anterior lacrimal crest, and a posterior bundle, which is thinner and more fragile, inserting on the posterior lacrimal crest. The lacrimal sac is located in the lacrimal groove, posterior to the medial canthal tendon¹.

Transnasal canthopexy was first described by Francoise Firmin in 1972 and then codified by Paul Tessier². To date, literature is scarce concerning the description of the technique for medial transnasal canthopexy, and several variations of the technique are described^3,4.

We aimed to describe a standardized, reproducible technique for bilateral medial transnasal canthopexy by an orbitonasal approach, based on Paul Tessier's technique, which our team has been experienced with for several years.⁵

Indeed, the execution of this technique is not always straightforward, especially in the case of bilateral medial canthopexy. This difficulty is explained by the need for successive transnasal passages of several wires with limited surgical access, as well as the small size and fragility of the medial canthal tendon. These factors make the execution of this technique challenging; it is thus important to carefully follow each step to achieve a good result.

Due to the difficulty of the technique, there is a need for a detailed protocol that will illustrate step by step the different stages of the procedure to facilitate learning and execution.

Protocol

The protocol follows the guidelines of the Hôpitaux Clocheville et Trousseau human research ethics committee. Informed consent was obtained from all participants for this study.

1. Pre-operative evaluation

1. Perform pre-operative evaluation of intercanthal distance with measurements of intercanthal distance with a caliper.
2. Perform a CT scan pre-operatively to evaluate orbital bone structures and ensure sufficient stability for the passage of the steel wires and fixation of the medial canthal tendon.

2. Installation

1. Under general anesthesia, position the patient supine, with centered oro-tracheal intubation.
2. Disinfect the patient according to the local protocol, and drape the patient using a sterile technique.
3. Disinfect the nasal fossa and endonasal wicking with naphazoline (storage and use at ambient temperature).
4. In addition to the standard precautions followed classically (hand disinfection, adapted sterile gloves), ensure eyewear protection, and follow particular precautions when using the steel wires to avoid cutaneous injury. Wearing two pairs of gloves is recommended.

3. Drawing of the incision lines

1. Draw the incision line on each side according to Tessier orbitonasal incision, following a bayonet-shaped line at the medial canthus, which continues with a sub-tarsal approach (Figure 1). Create a succession of broken lines to facilitate dissection and limit the risk of residual visible retractile scars.
2. In case of unilateral medial transnasal canthopexy, draw the incision line according to the Tessier orbitonasal approach at the affected side, and at the contralateral side, draw an arcuate incision line measuring approximately 1.5 cm, anterior to the medial canthal tendon (MCT) (Supplementary Figure 1).

4. Realization of the orbitonasal approach

1. Infiltrate the incision sites and the medial canthus region with subperiosteal infiltration with 1% adrenaline-lidocaine (storage at 2 °C and 8 °C, use at ambient temperature) in the absence of contraindication.
2. Perform a skin incision with an 11-scalpel blade until reaching the plane of the orbicularis muscle, extending laterally to the lateral canthus, according to the defined incision lines
3. Continue dissection with Ragnell scissors in the preseptal plane down to the periosteum, at the site of the infraorbital margin.
4. Perform incision of the periosteum with a 15-scalpel blade along the infraorbital margin.
5. Dissect the infraorbital margin in a subperiosteal plane with an elevator and roughen the orbital floor and medial wall for approximately 2 cm to obtain good exposure.
6. After exposure, probe the lower lacrimal passage with a lacrimal probe to facilitate dissection.
7. Gradually dissect medially the orbicularis muscle with Ragnell scissors until the MCT is exposed.
8. Isolate the MCT along its entire length and detach it from the periosteal plane with Ragnell scissors and an elevator.
9. Dissect the medial wall in a subperiosteal plane with an elevator, pushing the lacrimal sac downward, as well as the superior orbital rim and the inner part of the orbital roof. Take care not to fracture the very thin lamina papyracea during dissection.
10. Release the lacrimal passages and lacrimal sac up to the lacrimonasal canal with the use of an elevator.
11. Expose the ascending process of the maxilla with an elevator.

5. Performing the contralateral orbitonasal approach

1. Perform the contralateral orbitonasal approach according to the same procedure described previously (section 4).
2. In case of unilateral medial canthopexy, perform an orbitonasal approach at the affected side, the side where the medial canthus needs to be reinserted, and perform contralaterally, an arcuate incision line measuring approximately 1.5 cm with the use of a 15-scalpel blade, anterior to the MCT, measuring approximately 10 mm (Supplementary Figure 1).

6. Creating the transosseous wire

1. Perform the bony path: perforate the maxillary frontal process with the largest square pin (3 mm diameter) behind the anterior lacrimal crest or at the level of the posterior lacrimal crest, in a slightly backward direction in order to apply traction of the medial canthus in the direction of the orbital apex. Protect the eye and lacrimal sac with a malleable retractor during this step.
2. Then, use the fine square pin (1 mm diameter) to perforate the nasal septum with a posterior and deeper trajectory than the first perforation (step 6.1).
3. On the contralateral side, make the perforation at the level of the lacrimal crest, just above the superior border of the medial canthal tendon. Be sure to protect the eyeball and lacrimal sac during this step.

7. Creating a transnasal wire "shuttle" using non-locking 1 # steel wire for passing the metal threads through the bony defects

1. First, form a loop by folding the wire in half, ensuring it passes through the bone starting from one side towards the contralateral side.
2. Insert two additional loops head-to-head (Figure 2) using the first loop inserted at step 6.1; these loops will allow the passage of steel wires that will be inserted on the MCT (section 8), on each side.
   NOTE: Care must be taken to avoid tangling the wires when passing them through the nasal pyramid.
3. For unilateral medial canthopexy, perform step 7.1, insert the loop from the affected side to the contralateral side, and then only insert one additional loop, using the first loop inserted in step 7.1, as a guide.

8. Insertion of staged wires on the medial canthal tendon, and contralateral transnasal passage with the wire "shuttle"

1. Pass three different 3/0 locking steel wires through the medial canthal tendon carefully, ensuring a secure grip.
2. Cut each of the three wires with different lengths to avoid confusion and secure them with 'mosquito' clamps.
3. Pass the wires through the metal loop on the affected side in pairs and fold them onto themselves (Figure 3).
4. Gradually pull the loop, allowing the transnasal passage of the wires.
5. Once the loop is passed, remove it and place the different steel wires in pairs.
   NOTE: Care must be taken to avoid the patient's eye injury when passing the steel wires.

9. Contralateral fixation of the medial canthus tendon by blocking the steel wires on a metallic cleat

1. Create a metallic cleat by twisting and tightening three or four number 1 steel wires, each about 1 cm long, together.
2. Anchor the steel wires on the cleat, placed against the maxillary process. It is important to achieve an overcorrection.
3. Perform insertion of staged wires on the contralateral medial canthal tendon, contralateral transnasal passage with the wire "shuttle", and fixation of the medial canthus tendon by blocking the steel wires on a metallic cleat, as described previously (sections 8 and 9).

10. Skin closure

1. For orbitonasal approach closure, close in two layers: reapproximate the maxillary periosteum to the periorbital tissue using Polyglactin 4/0 sutures, and perform skin closure with Polypropylene 6/0 sutures.
2. For the contralateral side in case of unilateral canthopexy, close in one layer the skin with interrupted Polypropylene 6/0 sutures.
   NOTE: The procedure is now complete. Refer to standard institutional procedures to manage surgical and chemical waste (used steel wires, used sutures, etc).

11. Post-operative care

1. Administer artificial tears, application of ophthalmic ointment such as Sterdex (Oxytetracycline, Dexamethasone) twice daily, and use cold eye compresses (compresses soaked in cold physiological serum) for 48 h to reduce edema.
2. Monitor vision, including light perception, multiple times daily.
   NOTE: Frequency of ophthalmological check should be decided by the surgeon, in accordance with clinical aspects, post-operative evolution, and institutional practices.

Results

This technique is reliable and long-lasting. It is a technique that can be difficult to master, with a steep learning curve, and requires a methodical approach and careful adherence to the successive surgical steps to achieve satisfactory results. Concerning bilateral canthopexy, it is important to be particularly cautious, especially with the different steel sutures passed transnasally, to avoid mixing them up. It is crucial to perform the canthopexy using three different steel sutures to fix the lateral canthal ligamen...

Discussion

This technique does have certain limitations. In particular, it can be challenging to precisely determine the degree of overcorrection required to achieve an optimal outcome. The amount of tension applied to the steel sutures is not always easy to control, and tension-related asymmetry or relapse may occur. Using this technique, we experienced no minor or major complications. However, undercorrection of the medial canthal tendon, or relapse, may occur. Noticeably, transnasal canthopexy seems to achieve more stable result...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Adson Dissection Forceps without Hook L 120 mm	BBRAUN AESCULAP	BD220R
Beyer Double Articulating Gouge Curved L 160 mm D 2 mm	MICROFRANCE INTEGRA	CP380-2
Bipolar Cable Dual Input Ref 40493IP or HF0100034 or HF0100033	INTEGRAL PROCESS	4043IP
Bipolar Forceps L 160 mm	INTEGRAL PROCESS	080416A
Bistoury Handle No. 3 L 130 mm	BBRAUN AESCULAP	BB073R
Debakey Dissection Forceps L 150 mm Jaws 2 mm	BBRAUN AESCULAP	FB400R
Desmarres Retraction Forceps L 140 mm L 14 mm - 18 mm	BBRAUN AESCULAP	OA312R
Eyelid Retractor (One Pair)	BBRAUN AESCULAP	BT177R
Farabeuf Retractor (One Pair) L 110–150 mm	LANDANGER	B80130
Farabeuf Retractor (One Pair) L 120 mm H 20–25 mm L 7–9 mm	LANDANGER	B80120
Frazier Suction Cannula D 3 mm	LANDANGER	196010203
Gillies Dissection Forceps with Hook L 155 mm	BBRAUN AESCULAP	BD660R
Gillies Hook (One Pair)	LANDANGER	B80350
Halstead Hemostatic Forceps L 120–140 mm with Curved Hook	LANDANGER	B50420
Halstead Hemostatic Forceps without Curved Hook L 120–125 mm	LANDANGER	BH111R
Hasley Needle Holder L 130 mm with Tungsten BM012R	BBRAUN AESCULAP	BM012R
Iridectomy Scissors Curved L 105–120 mm	LANDANGER	B89005
Iridectomy Scissors Straight L 105 mm	MEDLANE	3403
Kerrison Bone Punch L 180 mm Jaws 90° 2 mm	BBRAUN AESCULAP	FK949R
Kocher Hemostatic Forceps with Hooks Straight L 160 mm	LANDANGER	B50210
Malleable Blade L 210 mm L 10 mm - 12 mm - 15 mm - 17 mm - 20 mm	MICROFRANCE INTEGRA	CP818-10
Mayo Curved Scissors L 150 mm without Tungsten	LANDANGER	B25485
Micro Adson Dissection Forceps with Hook L 120 mm	BBRAUN AESCULAP	BD510R
Obwegeser Osteotome L 230 mm Curved Width 11 mm	BBRAUN AESCULAP	DO720R
Obwegeser Osteotome L 230 mm Curved Width 8 mm	STYKER	01-17852
Obwegeser Rasp A B C D L 180 mm	MICROFRANCE INTEGRA	CP344A B C D
Obwegeser Rasp Sharp AT BT L 180 mm	MICROFRANCE INTEGRA	CP344AT CP344BT
Ragnell Curved Scissors L 150 mm	MICROFRANCE INTEGRA	CP616-15
Ruler L 200 mm	KLS MARTIN	17-412-20-07
Ryder Needle Holder L 135 mm Jaws 2 mm with Tungsten	BBRAUN AESCULAP	BM054R
Square Pin	KLS MARTIN	48.316.21.07
Tessier Scissors L 140 mm Straight Sharp without Tungsten	LANDANGER	B89030