Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model

Abstract

OBJECTIVE The subtemporal approach is one of the surgical routes used to reach the interpeduncular fossa. Keyhole subtemporal approaches and zygomatic arch osteotomy have been proposed in an effort to decrease the amount of temporal lobe retraction. However, the effects of these modified subtemporal approaches on temporal lobe retraction have never been objectively validated. METHODS A keyhole and a classic subtemporal craniotomy were executed in 4 fresh-frozen silicone-injected cadaver heads. The target was defined as the area bordered by the superior cerebellar artery, the anterior clinoid process, supraclinoid internal carotid artery, and the posterior cerebral artery. Once the target was fully visualized, the authors evaluated the amount of temporal lobe retraction by measuring the distance between the base of the middle fossa and the temporal lobe. In addition, the volume of the surgical and anatomical corridors was assessed as well as the surgical maneuverability using navigation and 3D moldings. The same evaluation was conducted after a zygomatic osteotomy was added to the two approaches. RESULTS Temporal lobe retraction was the same in the two approaches evaluated while the surgical corridor and the maneuverability were all greater in the classic subtemporal approach. CONCLUSIONS The zygomatic arch osteotomy facilitates the maneuverability and the surgical volume in both approaches, but the temporal lobe retraction benefit is confined to the lateral part of the middle fossa skull base and does not result in the retraction necessary to expose the selected target.

The Subtemporal Approach to the Lateral Midbrain with and without Zygomatic Osteotomy: An Anatomical Study

“…The transzygomatic subtemporal approach seeks to widen the surgical corridor underneath the temporal lobe and reducing the need for temporal lobe retraction. It has been shown in a previous anatomic study, that in fact the surgical field is increased through a zygomatic osteotomy (Ercan et al, 2017). In agreement with others, here we show that a zygomatic osteotomy significantly increases the working angle of the subtemporal approach, facilitating surgery in this area and reducing the risk of temporal contusion through retraction.…”

Indications and Safety of the Zygomatic Osteotomy in Middle Cranial Fossa Surgery: A Retrospective Cohort Review

“…The results are divided; some studies posit that with the additional maneuverability conferred by the zygomatic osteotomy more lesions can be reached safely, whereas others suggest that the operative window is relatively unimproved except for extensive lesions or those reaching into the infratemporal fossa. [11][12][13][14][15] The majority of these studies focused on lesion location. However, in our study the lesion location was largely the same, the medial part of the MCF.…”

Letter to the Editor. Blunt cerebrovascular injuries in severe TBI

“…As has been stated before, there are tools to evaluate and prove/disprove new surgical techniques. 1,2 The phrase "in our experience" is somehow of a circular self-referential nature that, unless pointing to quantum leap improvement in measurable outcome, has very little substance.…”

“…TO THE EDITOR: Recently, Ercan and colleagues 1 published their cadaveric laboratory investigation of keyhole versus a traditionally sized craniotomy with and without zygomatic osteotomy to assess temporal lobe retraction and surgical exposure via a subtemporal corridor (Ercan S, Scerrati A, Wu P, et al: Is less always better? Keyhole and standard subtemporal approaches: evaluation of temporal lobe retraction and surgical volume with and without zygomatic osteotomy in a cadaveric model.…”