Transnasal Endoscopic Repair of Orbital Floor Fracture with Alloplastic Implant

Objective: This study aims to report on the feasibility of transnasal endoscopic repair of isolated orbital floor fractures.

Introduction: Numerous methods exist for repair of the isolated orbital floor fracture. Traditionally, periorbital approaches (subciliary, subtarsal, and transconjunctival) provide direct visualization of the defect and orbital contents while providing excellent access for repair. These approaches do carry a real risk of lower eyelid malposition. The transantral approach to the orbital floor has become popular among many surgeons for the avoidance of the complications associated with periorbital incisions. Several studies have shown the feasibility of the Caldwell-Luc approach with implant placement for rigid reconstruction of the orbital floor defect. The transnasal endoscopic approach, through maxillary antrostomy and reduction of the orbital fat with balloons and/or packing, has also been described, but this has failed to incorporate a rigid reconstruction. We have proposed a technique, which utilizes rigid reconstruction of the orbital floor via a solely trans-nasal endoscopic approach.

Study Design: This is a cadaveric anatomical study and case series.

Methods: Anatomical dissections were performed on methanol-embalmed cadaveric specimens using standard transnasal endoscopic techniques and instrumentation. An isolated orbital floor fracture was created in each specimen via directed trauma through the orbit. The orbital floor was accessed via an extended maxillary antrostomy using a 30-degree Hopkins rod telescope. Herniated orbital contents were manipulated and reduced using endoscopic probes. Nonreducible bone fragments were removed. The defect was then repaired by inlay of titanium reinforced porous polyethylene plate (MEDPOR TITAN, Stryker Corporation, Kalamazoo, Michigan, United States), supported by stable portions of the native orbital floor.

Two illustrative cases of successful transnasal endoscopic repair of isolated orbital floor fracture are presented. High-definition intraoperative and postoperative images are provided alongside idealized anatomic representations from the cadaveric dissections to identify appropriate anatomical landmarks and the limitations of this approach in regard to fracture size and location.

Results: In both representative cases, a posteriorly located, isolated floor fracture was successfully exposed and repaired solely via transnasal endoscopic techniques. There were no postoperative complications. On the basis of cadaveric dissections and the patient cases, this technique is best suited for posterior and medial fractures. The placement of the plate is most easily achieved if the fracture happens to be medial to the infraorbital nerve canal. If the fracture involves the infraorbital nerve canal, dissection around the nerve is imperative. The plate should be positioned between the nerve and the herniated fat to prevent impingement of the nerve close to the infraorbital foramen.

Conclusion: Successful repair of favorable isolated orbital floor fractures can be achieved through entirely transnasal endoscopic techniques, even when placement of an alloplastic implant is required for repair. No complications are identified in the immediate postoperative period or short-term follow-up. Absorbable plates are also an option to be considered. Further investigation is warranted in regards to long-term outcomes, as well as complication rates in comparison to both open periorbital and endoscopic transantral approaches.