title: Interactive navigation-guided ophthalmic plastic surgery: the utility of 3D CT-DCG-guided dacryolocalization in secondary acquired lacrimal duct obstructions.
abstract: OBJECTIVE
  The aim of this study was to report the preliminary experience with the techniques and utility of navigation-guided, 3D, computed tomography-dacryocystography (CT-DCG) in the management of secondary acquired lacrimal drainage obstructions.
  
  
  METHODS
  Stereotactic surgeries using CT-DCG as the intraoperative image-guiding tool were performed in 3 patients. One patient had nasolacrimal duct obstruction (NLDO) following a complete maxillectomy for a sinus malignancy, and the other 2 had NLDO following extensive maxillofacial trauma. All patients underwent a 3D CT-DCG. Image-guided dacryolocalization (IGDL) was performed using the intraoperative image-guided StealthStation™ system in the electromagnetic mode. All patients underwent navigation-guided powered endoscopic dacryocystorhinostomy (DCR). The utility of intraoperative dacryocystographic guidance and the ability to localize the lacrimal drainage system in the altered endoscopic anatomical milieu were noted.
  
  
  RESULTS
  Intraoperative geometric localization of the lacrimal sac and the nasolacrimal duct could be easily achieved. Constant orientation of the lacrimal drainage system was possible while navigating in the vicinity of altered endoscopic perilacrimal anatomy. Useful clues with regard to modifications while performing a powered endoscopic DCR could be obtained. Surgeries could be performed with utmost safety and precision, thereby avoiding complications. Detailed preoperative 3D CT-DCG reconstructions with constant intraoperative dacryolocalization were found to be essential for successful outcomes.
  
  
  CONCLUSIONS
  The 3D CT-DCG-guided navigation procedure is very useful while performing endoscopic DCRs in cases of secondary acquired and complex NLDOs.
authors.affiliation: Govindram Seksaria Institute of Dacryology.
authors.forename: Mohammad Javed
authors.initials: MJ
authors.lastname: Ali
authors.affiliation: Govindram Seksaria Institute of Dacryology.
authors.forename: Swati
authors.initials: S
authors.lastname: Singh
authors.affiliation: Govindram Seksaria Institute of Dacryology.
authors.forename: Milind N
authors.initials: MN
authors.lastname: Naik
authors.affiliation: The Operation Eyesight Universal Institute for Eye Cancer, L V Prasad Eye Institute, Hyderabad, Telangana, India.
authors.forename: Swathi
authors.initials: S
authors.lastname: Kaliki
authors.affiliation: Govindram Seksaria Institute of Dacryology.
authors.forename: Tarjani Vivek
authors.initials: TV
authors.lastname: Dave
keywords: CT-dacryocystography; image guidance; lacrimal drainage; nasolacrimal duct obstruction; navigation; powered endoscopic DCR