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A Technique for Medial Canthal Fixation Using Resorbable Poly-L-lactic Acid–Polyglycolic Acid Fixation Kit
Vidushi Sharma, MD, FRCS;
Arik Nemet, MD;
Raf Ghabrial, FRANZCO;
Peter A. Martin, FRANZCO;
Gina Kourt, FRANZCO;
Jenny J. Danks, FRANZCO;
George Marcells, FRANZCS
Arch Ophthalmol. 2006;124:1171-1174.
ABSTRACT
Achieving secure bony fixation of medial canthus is a challenge. We used a resorbable poly-L-lactic acid–polyglycolic acid screw (LactoSorb office fixation kit) in 5 cases: 2 with traumatic medial canthal dystopia, 1 with scleroderma and orbital fat atrophy causing malapposition of the medial canthus to globe, and 2 with invasive medial canthal tumors necessitating subtotal medial orbital exenteration. The resorbable screw with preplaced suture was drilled into the medial orbital wall, using a handheld self-drilling tap. The preplaced suture was used to anchor the medial canthus. We achieved satisfactory canthal position in all 5 cases. There were no complications in 4 cases during a mean ± SD follow-up of 11.3 ± 6 months; however, the scleroderma case developed wound dehiscence 6 weeks after surgery. The LactoSorb kit is a safe and effective technique to achieve bony medial canthal fixation in carefully selected cases.
INTRODUCTION
Medial canthal reattachment may be required in a variety of cases such as medial canthal malposition and lower lid ectropion due to trauma, scarring, and laxity or in cases that involve iatrogenic disinsertion of the medial canthal tendon (MCT) during craniofacial procedures or excision of tumors invading the medial orbit. Secure bony fixation of the medial canthal structures remains a difficult surgical challenge.1-2 The adequate positioning and fixation of the MCT for proper intercanthal distance, canthal depth, and apposition of the eyelid to the globe constitute the cornerstone of a successful reconstruction.2 Various techniques have been used in the past for this purpose, such as transnasal wiring, titanium screws,3 titanium miniplates cantilevered from the nose,4 commercially available anchoring systems (such as those from Mitek Inc, Westwood, Mass),5-6 periosteal flaps,7 and medial tarsal strips.8 Some of these are difficult to perform or lead to complications owing to the presence of metallic foreign bodies,1 especially if they lie in a potentially infected space like the nasal cavity.5 Although periosteal flaps and tarsal strips avoid the complications associated with foreign bodies, these are not as successful in the medial orbit as they are in the lateral orbit because of the difficulty of getting strong periosteal flaps and the risk of causing canalicular injury in cases where the lacrimal system is still functioning.8 The use of resorbable poly-L-lactic acid–polyglycolic acid fixation devices to achieve secure bony fixation of soft tissue structures has been reported in many large series of craniomaxillofacial surgeries.9 The LactoSorb office fixation kit (Walter Lorenz Surgical, Jacksonville, Fla) has been designed for endobrow fixation to perform brow-lifts. We used this kit to achieve medial canthal fixation in 5 difficult reconstructive procedures and found it to be a suitable device to achieve firm bony fixation of the medial canthus in carefully selected cases.
METHODS
We used the LactoSorb office fixation kit in 5 cases requiring medial canthal reconstruction and reattachment of the medial canthus. The surgical procedures were performed in all cases after obtaining written informed consent.
REPORT OF CASES
Case 1
A 69-year-old man sustained trauma to the left side of his face during a road traffic accident 2 years earlier. The trauma caused multiple orbital and nasoethmoidal fractures, as well as injury to the eyelids, medial canthus, and canalicular system. He underwent 3 reparative and reconstructive surgical procedures in the periocular and nasal areas, resulting in a downward shift of the medial canthus associated with extensive scarring (Figure 1A). Computed tomographic findings showed a surgical metallic clip in the inferior orbit used for repair of the inferior orbital margin, which was irregular, and another clip used for repairing the medial orbit.
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Figure 1. Case 1. A, Preoperative view showing severe downward displacement of the medial canthus associated with extensive posttraumatic scarring. B, Postoperative view, taken 2 months after the repair, showing significant improvement of the medial canthal position.
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Case 2
A 57-year-old woman had progressive fat atrophy of the facial region for the past 30 years. Scleroderma resulting in lipoatrophy was diagnosed on the basis of skin biopsy findings. The extensive loss of orbital fat resulted in epiphora due to the separation of the lower eyelid away from the globe.
Cases 3 and 4
Two cases had recurrent medial canthal basal cell carcinoma with medial orbital invasion. A subtotal medial orbital exenteration was performed with excision of the carcinoma. The MCT was found to be disorganized and ill-defined, and the medial canthus had to be reattached at the end of surgery.
Case 5
A 35-year-old man sustained severe facial trauma due to an assault 6 years earlier that resulted in injury to the medial canthus and nasal bones. He underwent 2 surgical repairs and a rhinoplasty before being referred for unilateral telecanthus and mild downward shift of the right medial canthus.
The clinical features of these cases are summarized in the Table. All cases involved complex reconstruction of the medial canthus, which is difficult to perform with the traditionally used methods for medial canthal reattachment.
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Table. Clinical Features of the Cases Undergoing Medial Canthal Repair Using a Resorbable Fixation System*
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SURGICAL TECHNIQUE
The surgical technique used was slightly different for the separate cases. Essentially, the objective was to anchor the medial canthal tissues to the medial orbital wall, near the posterior lacrimal crest and superior to it, so as to give it an appropriate depth. It is advisable to overcorrect for the medial canthal dystopia because it tends to move back in the preoperative direction after healing. An extensive dissection was performed to release all of the scar tissue or to remove the entire tumor. The LactoSorb handheld self-drilling tap was then used to drill a hole in the medial orbital wall at the desired site for medial canthal reattachment (Figure 2A). Care was taken in all cases not to cause any injury to the lacrimal system. The 2 x 5-mm LactoSorb screw with a preplaced suture and a twistable head (Figure 2B) is loaded into the driver and snugly placed in this hole (Figure 2C). The head is then twisted off. Alternatively, the screw can be placed first and the suture passed through it later. The hole in the screw head is designed to accept a 2-0 or 3-0 suture and comes with a suture passer. We used a 2-0 polydioxanone (PDSII) suture (Ethicon Inc, Somerville, NJ). The whole procedure of drilling the hole and positioning the screw with the preplaced suture was fairly simple and took less than 5 minutes. The polydioxanone suture was then used to secure the medial canthal tissues to the screw, so as to achieve a firm bony fixation. The MCT was secured at a site before its division into the different limbs.1 If the MCT was damaged as a result of trauma, a firm bite was taken through the medial canthal tissues with the suture. The skin incision was sutured with 6-0 polyglactin 910 (Vicryl; Ethicon Inc). A skin graft was also performed in case 2 to compensate for the tight and stretched skin in the medial canthal area. A flap of nasal skin was rotated and sutured into the defect in case 1, after freeing all the scar tissue. A Y-V–plasty, which is typically performed for telecanthus or epicanthal folds, was done in case 5.
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Figure 2. Intraoperative photographs demonstrating insertion of a resorbable fixation system (LactoSorb office fixation kit; Walter Lorenz Surgical, Jacksonville, Fla). A, A hole is drilled in the medial orbital wall using a self-drilling tap. B, Close-up photograph of the actual screw used in the technique. The arrow shows the site of the hole in the screw head for placing the suture. C, The screw with its detachable head is loaded into the driver and placed into the bony hole. The white arrow shows the site of placement of the screw; the black arrow, the preplaced 2-0 polydioxanone suture. The head is then twisted off and removed from the driver.
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The postoperative medial canthal position was considered satisfactory in all 5 patients (Figure 1B), showing a considerable improvement compared with the preoperative position. Four cases experienced no complications related to the surgery or the devices used during a mean ± SD follow-up of 11.3 ± 6 months. These 4 cases maintained their canthal position during the follow-up period. However, case 5 had a wound dehiscence 6 weeks after surgery, resulting in medial canthal detachment.
COMMENT
The medial canthus is an important structure for aesthetic and functional reasons. It helps maintain the normal angular contour of the eye, helps prevent epiphora by assisting the lacrimal pump mechanism, and helps prevent ectropion.1 Medial canthal deformities can result from nasoethmoidal trauma, cancer resection, craniofacial exposure, congenital malposition, or age-related change.1, 5 Various techniques have been used for medial canthal reconstruction, specifically to achieve bony fixation of the MCT. Most of these are generally difficult to perform and may cause complications related to the metallic fixation devices used. Therefore, we used a resorbable screw fixed into the bone, which provides a secure bony anchoring of the medial canthus and avoids many of the complications associated with the use of metallic fixation devices.
Transnasal wiring has been one of the most commonly used methods to perform medial canthopexy.4-5 However, it is technically difficult and may cause damage to the contralateral orbital structures.5 Complications related to the use of metallic devices may occur in the form of device loosening, skin irritation, and device exposure or extrusion.9 The LactoSorb system avoids most of these complications because it is fully absorbed in less than 1 year. Also, the use of polydioxanone, an absorbable suture, avoids the possibility of suture exposure or extrusion and yet provides good support for up to 6 weeks.
The use of metallic titanium devices requires an adequately strong bone as a prerequisite.5 Although the LactoSorb system also requires stability of bone to achieve a secure medial canthal fixation, the flexibility of the material and the self-drilling taps allow for a less traumatic placement in the bone. This is the reason behind our good results, even in case 1, which had previous bony repairs for multiple fractures. The disadvantage of this procedure is that it cannot be used in cases with deficient bone, where transnasal wiring may be the only alternative.5
The resorbable plate-and-screw devices were introduced in 1996 and have since been used without significant complications in thousands of patients undergoing craniofacial procedures, including children younger than 2 years, demonstrating the safety of the material.9 The LactoSorb system is made from a combination of the copolymers poly-L-lactic acid and polyglycolic acid (82% and 18%, respectively). This polyester derivative of L-lactic and glycolic acids has retained fixation strength that persists up to 6 weeks following implantation, with complete resorption of the devices 9 to 15 months after surgery.9 The LactoSorb material is safe, and in 1 large series9 of craniofacial procedures, reoperation resulting from device-related problems (eliminating infection, which could not be confirmed as being directly related to the device rather than the operation) was required in 0.23% of 1883 patients. Although it is theorized that polymer devices have a higher affinity for bacterial adhesion, the infection rate was as low as 0.4% in that large series.9 Foreign-body reactions to the degrading polymer have been seen in 0.7% of cases from 3 to 9 months postoperatively, at the time of the most active degradation.9 However, these reactions were minor, transient, and self-limiting and would be a much lesser concern in medial canthal fixation cases, where only a screw with less volume of the polymer is used compared with the large plates used in craniofacial procedures. The cost of the screws at $95 per pair is a relative disadvantage, but they are still less expensive than the other available titanium fixation devices.10 Also, the ease of use and minimal hand-operated equipment make it a practical choice for ophthalmic practices.
The MCT is considered to be a tripartite structure with anterior, posterior, and superior limbs. It has been demonstrated that the vector of the 3 limbs of the MCT points just superior and posterior to the attachment of the anterior limb.11 The correct site of placement of the LactoSorb screw is crucial to the results.5 However, various authors have attached the MCT at different sites on the medial orbital wall, including the anterior lacrimal crest, superior to the anterior lacrimal crest,5 and the posterior lacrimal crest.12 We used the posterior lacrimal crest, behind the lacrimal sac, and we think that this provides a normal depth to the medial canthus.
Despite many techniques, medial canthopexy remains a difficult procedure, and many surgeries fail as a result of postoperative scar contraction, exaggerated pull on the wires, and infection.5 Case 2 was an exceptionally difficult one, and we believe that too much stress on the tendon-bone attachment site and the skin resulted in a total wound dehiscence, opening the medial canthus.
We believe that the LactoSorb office fixation kit is a suitable device for cases requiring reattachment of the MCT. It is a safe material and avoids many of the complications related to metallic fixation devices. It can also be used in cases where the MCT has been partly damaged. It is easy to use and gives good results in carefully selected cases. However, experience with more cases will be helpful to confirm the initial observations from this preliminary study.
AUTHOR INFORMATION
Correspondence: Vidushi Sharma, MD, FRCS, SuVi Eye Institute, A-475, Indra Vihar, Kota, Rajasthan, India (svidushi{at}hotmail.com).
Submitted for Publication: September 3, 2005; final revision received January 23, 2006; accepted February 3, 2006.
Financial Disclosure: None reported.
Previous Presentations: This study was presented in part as a poster at the Annual Meeting of Royal Australian and New Zealand College of Ophthalmologists; November 14-18, 2004; Melbourne, Australia; and at the Annual Meeting of the Association for Research in Vision and Ophthalmology; May 1-5, 2005; Fort Lauderdale, Fla.
Author Affiliations: Oculoplastic Units, Sydney Eye Hospital (Drs Sharma, Nemet, Ghabrial, Martin, Kourt, and Danks), Concord Repatriation Hospital (Dr Ghabrial), and St Vincent's Hospital (Dr Danks), and Otorhinolaryngology Unit, Sydney Hospital (Dr Marcells), Sydney, Australia. Dr Sharma is now with the SuVi Eye Institute, Kota, Rajasthan, India.
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