Expanding the limits of endoscopic intraorbital tumor resection using 3-dimensional reconstruction

Braz J Otorhinolaryngol. Mar-Apr 2019;85(2):157-161. doi: 10.1016/j.bjorl.2017.11.010. Epub 2017 Dec 26.

Abstract

Introduction: Endoscopic orbital surgery is a nascent field and new tools are required to assist with surgical planning and to ascertain the limits of the tumor resectability.

Objective: We purpose to utilize three-dimensional radiographic reconstruction to define the theoretical lateral limit of endoscopic resectability of primary orbital tumors and to apply these boundary conditions to surgical cases.

Methods: A three-dimensional orbital model was rendered in 4 representative patients presenting with primary orbital tumors using OsiriX open source imaging software. A 2-Dimensional plane was propagated between the contralateral nare and a line tangential to the long axis of the optic nerve reflecting the trajectory of a trans-septal approach. Any tumor volume falling medial to the optic nerve and/or within the space inferior to this plane of resectability was considered theoretically resectable regardless of how far it extended lateral to the optic nerve as nerve retraction would be unnecessary. Actual tumor volumes were then superimposed over this plan and correlated with surgical outcomes.

Results: Among the 4 lesions analyzed, two were fully medial to the optic nerve, one extended lateral to the optic nerve but remained inferior to the plane of resectability, and one extended both lateral to the optic nerve and superior to the plane of resectability. As predicted by the three-dimensional modeling, a complete resection was achieved in all lesions except one that transgressed the plane of resectability. No new diplopia or vision loss was observed in any patient.

Conclusion: Three-dimensional reconstruction enhances preoperative planning for endoscopic orbital surgery. Tumors that extend lateral to the optic nerve may still be candidates for a purely endoscopic resection as long as they do not extend above the plane of resectability described herein.

Keywords: Abordagem endonasal endoscópica; Endoscopic endonasal approach; Nasal surgical procedures; Orbit; Orbital tumors; Otorhinolaryngologic surgical procedures; Procedimentos cirúrgicos nasais; Procedimentos cirúrgicos otorrinolaringológicos; Tumores orbitais; Órbita.

MeSH terms

  • Humans
  • Imaging, Three-Dimensional / methods*
  • Magnetic Resonance Imaging
  • Optic Nerve / diagnostic imaging
  • Optic Nerve / surgery
  • Orbital Neoplasms / diagnostic imaging*
  • Orbital Neoplasms / pathology
  • Orbital Neoplasms / surgery*
  • Preoperative Period
  • Reconstructive Surgical Procedures / methods*
  • Software
  • Tomography, X-Ray Computed
  • Transanal Endoscopic Surgery / methods*
  • Treatment Outcome
  • Tumor Burden