The 1-piece transbasal approach: operative technique and anatomical study

Abstract

Object The transbasal approach (TBA) is an anterior skull base approach, which provides access to the anterior skull base, sellar-suprasellar region, and clivus. The TBA typically involves a bifrontal craniotomy with orbital bar and/or nasal bone osteotomies performed in 2 separate steps. The authors explored the feasibility of routinely performing this approach in 1 piece with a quantitative cadaveric anatomical study, and present an operative case example of their approach. Methods Seven latex-injected cadaveric heads underwent a 1-piece TBA, followed by additional bone removal typical for a traditional 2-piece approach. Six surgical angles relative to the pituitary stalk, as well as the surface area of the orbital roof osteotomy, were measured before and after additional bone removal. The vertical angle from the frontonasal suture to the foramen cecum was measured in all specimens. In addition to an anatomical study, the authors have used this technique in the operating room, and present an illustrative case of resection of an anterior skull base meningioma. Results Morphometric results were as follows: the vertical angle from the frontonasal suture to the foramen cecum ranged from 17.4° to 29.7° (mean 23.8° ± 4.8°) superiorly. Of the 6 surgical angle measures, only the middle horizontal angle was increased in the 2-piece versus the 1-piece approach (mean 43.4° ± 4.6° vs 43.0° ± 4.3°, respectively; p = 0.049), with a mean increase of 0.4°. The surface area of the orbital osteotomy was increased in the 2-piece versus the 1-piece approach (mean 2467 mm2 ± 360 mm2 vs 2045 mm2 ± 352 mm2, respectively; p < 0.001). The patient in the illustrative clinical case had a good outcome, both clinically and cosmetically. Conclusions The 1-piece TBA provides an alternative to the traditional 2-piece approach. It allows easier reconstruction, potentially decreased operative time, and improved cosmesis. While more of the orbital roof can be removed with the 2-piece approach, this additional bone removal offers only a small increase in 1 of 6 surgical angles that were measured.

Midline Meningiomas of the Anterior Skull Base: Surgical Outcomes and a Decision-Making Algorithm for Classic Skull Base Approaches

“…Interestingly, clinical outcomes did not substantially differ when comparing the "classic" approaches in this cohort to more complex skull-base approaches. These differences bring into question their routine use and use for selected cases [9,21,[40][41][42]. In the present cohort, interhemispheric and subfrontal approaches are associated with higher rates of relevant cognitive disorders after surgery, as controversially discussed in earlier publications [4,[43][44][45].…”

The evolving role of the oculoplastic surgeon in skull base surgery

“…This approach is differentiated from the transfrontal approach in which no osteotomies are made at the nasofrontoorbital bone segment. Orbital bar and/or nasal bone osteotomies can be performed in one piece [18]. The addition of the osteotomies allows broad exposure from below, lessening brain retraction compared to the transfrontal approach [19].…”