Combination of Navigation and Endoscope Assisted Orbital Reconstruction

Combination of Navigation and Endoscope assisted orbital reconstruction

Chien-Tzung Chen, M.D. Professor

Email: ctchenap@cgmh.org.tw

Department of Plastic and Reconstructive Surgery, Chang Gung Memorial Hospital, at Keelung, Taiwan

Disclosure of financial interest: the author had no any financial support for this project

Abstract

Background: Orbital fractures were among one of the most common facial fracture. Usually, the assessment of adequate orbital reconstruction was achieved by subjective visual inspection and palpation and objective anatomic reference and also much dependent on surgeon experience. The sequel of inadequate orbital reconstruction may result in enophthalmos, hypoglobus and diplopia. There was high incidence (8.5%) of increased orbital volume after orbital repair. In order to increase the accuracy of surgical procedure, navigation assisted tool has been applied to variable surgical field including neurosurgery, orthopedic surgery, ENT and facial plastic surgery.  Here, we reported our experience in combing navigation and endoscopic tool to assist surgery for primary and secondary orbital reconstruction.

Materials and Method: Between March of 2012 and March of 2014, 24 patients with a mean age of 39.3 year underwent unilateral primary and secondary orbital reconstruction. There were 14 male and 10 female. The average operation time lag was 529 days with 16 patients greater than one month after injury. 14 of them also had previous orbital reconstruction. 7 patient had single orbital wall fractures, the rest had 2 wall and greater than 2 wall reconstruction. 50% of patients had enophthalmos ≥ 2mm with an average of 2 mm. 13 patients had symptoms of diplopia.

Preoperative the spiral computed tomographic was performed with at least 1 mm slice. The BrainLAB CMF simulation software was used for Dicom data processing including object creation, mirroring of normal side to the lesion side, objective data measurement and data export. Intra-operatively, navigation assisted tool in combination of endoscope were applied for primary and secondary orbital reconstruction through transconjunctival or transnasal approach. The medpor alloplastic implant was used for most patients except one patient used iliac bone graft. The postoperative CT scan was obtained at least 3 months after surgery to confirm the surgical results.

Results:

All of the patients did not have any complications related to navigation tool. The mean follow up time was 9 months. One patient had residual enophthalmos more than 2 mm and received 2^nd orbital reconstruction. Only two patients had 1 mm enophthalmos and the rest had symmetric eyeball projection.  The postoperative diplopia still presented in 11 patients although the symptom improved than preoperative status.

Conclusion: the navigation assisted tool provided the convenience of pre-surgical plan for adequate analysis of pathology. It increased intraoperative accuracy, avoided injury to vital structure, reduced procedure invasiveness, facilitated minimal incision and endoscope use, and improved patient outcome under safe procedure.  The main disadvantage was extra cost of machine, and additional time for pre-surgical planning and registration. However, it could be compensated by quick confirmation of surgical result via navigation tool without hesitation intra-operatively.