Endoscopic sublabial transmaxillary approach to the inferior orbit: pearls and pitfalls-A comparative anatomical study.

Affiliation

Donofrio CA(1)(2), Riccio L(3), Pathmanaban ON(4), Fioravanti A(5), Caputy AJ(6), Mortini P(3).
Author information:
(1)Department of Neurosurgery and Gamma Knife Radiosurgery, IRCCS San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy. [Email]
(2)Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Stott Lane, Manchester, M6 8HD, UK. [Email]
(3)Department of Neurosurgery and Gamma Knife Radiosurgery, IRCCS San Raffaele Scientific Institute, Vita-Salute San Raffaele University, Milan, Italy.
(4)Department of Neurosurgery, Manchester Centre for Clinical Neurosciences, Salford Royal NHS Foundation Trust, Manchester Academic Health Sciences Centre, University of Manchester, Stott Lane, Manchester, M6 8HD, UK.
(5)Department of Neurosurgery, Azienda Socio Sanitaria Territoriale Cremona, Ospedale di Cremona, Cremona, Italy.
(6)Department of Neurosurgery, George Washington Hospital, George Washington University School of Medicine and Health Sciences, Washington, D.C., USA.

Abstract

OBJECTIVE: Although orbital surgery has always represented a challenge for neurosurgeons, keyhole and endoscopic techniques are gradually surging in popularity maximizing functional and esthetic outcomes. This quantitative anatomical study first compared the surgical operability achieved through three endoscopic approaches within the inferior orbit: the endoscopic sublabial transmaxillary (ESTMax), the endoscopic endonasal transethmoidal (EETEth), and the endoscope-assisted lateral orbitotomy (ELO). METHODS: Each of these approaches was performed bilaterally on five specimens. We described the ESTMax step-by-step, underlining its advantages and pitfalls in comparison with EETEth and ELO. Then, we assessed surgical measurements and operability in ESTMax, EETEth, and ELO. RESULTS: The ESTMax provided the most favorable operative window (278.9 ± 43.8 mm2; EETEth: 240.8 ± 21.5 mm2, p < 0.001; ELO: 263.1 ± 19.8 mm2, p = 0.006), the broadest surgical field area (415.9 ± 26.4 mm2; EETEth: 386.7 ± 30.1 mm2, p = 0.041; ELO: 305.2 ± 26.3 mm2, p < 0.001), surgical field depths significantly shorter than EETEth (p < 0.001) but similar to ELO, the widest surgical angles of attack (45°-65°; EETEth: 20°-30°, p < 0.001; ELO: 25°-50°, p < 0.001), and the greatest surgical mobility areas (EETEth: p < 0.001; ELO: p < 0.001). Furthermore, the ESTMax allowed multi-angled exposure and handy maneuverability around all the inferior intraorbital targets. Small anterior antrostomy, blunt intraorbital dissections, direct targets' approach, orbital floor reconstruction, and maxillary bone flap replacement may limit the ESTMax morbidity rates. CONCLUSIONS: The ESTMax is a minimally invasive "head-on" orbital approach that exploits endoscopic surgery advantages avoiding the cranio-orbital and trans-nasal approach limitations and possible complications. It represents a promising alternative to EETEth and ELO because of its optimal operability for resecting lesions extending into the entire inferior orbit.