Quantification of clival and paraclival exposure in the Le Fort I transmaxillary transpterygoid approach: a microanatomical study

Abstract

The authors describe a modified Le Fort I maxillotomy with medial and posterior antrectomy and removal of the pterygoid plates, aimed at improving the lateral surgical exposure during open transmaxillary surgery for pathological conditions involving the clivus. A cadaveric microanatomical study was conducted to compare the planimetric exposures allowed by the transmaxillary transpterygoid (TMTP) approach and the standard Le Fort I maxillotomy (STM). Six cadaveric specimens that had been fixed with glutaraldehyde and injected with latex were dissected to obtain morphometric measurements after both TMTP and STM approaches. The anatomical areas exposed by the surgical approaches were calculated using ImageJ 1.37a software. As expected, the TMTP approach allowed for a greater surgical exposure, with an incremental area exposed ranging from 4.9 to 7.6 cm(2) (mean ± standard deviation 6.4 ± 1.2 cm(2), 95% CI 5.4-7.4 cm(2)). The amount of additional anatomical area visualized, as recorded as a percentage increase after the TMTP approach when compared with the STM approach, ranged from 83 to 109% (mean 99%). The lateral surgical exposure allowed by the STM approach is limited by the pterygoid plates. The TMTP approach significantly improves the exposure of the anatomical regions lateral to the clivus, allowing access to the pterygopalatine and medial infratemporal fossae. In comparison with the STM, the TMTP approach allows for a surgical exposure that is nearly double. The authors conclude that the TMTP approach provides a significant improvement in the surgical exposure of the lateral paraclival areas, when compared with the STM approach.