The minipterional craniotomy: technical description and anatomic assessment.

Objective: To describe a modification of the pterional approach (PT), the minipterional craniotomy (MPT), and compare the anatomic exposure provided by these two approaches.

Methods: The anatomic exposure offered by the MPT and PT were compared in eight sides of cadaver heads using a computerized tracking system, a robotic microscope, and an image-guidance system. The area of surgical exposure, angular exposure, and anatomic limits of each craniotomy were evaluated. Three recently operated clinical cases (EGF) are also reported.

Results: There were no statistical differences in the total area of surgical exposure between the two craniotomies (PT, 1524.7 +/- 305 mm; MPT, 1469.7 +/- 380.3 mm; P > 0.05) or among the ipsilateral, middle, and contralateral components of the area (P > 0.05). There were no differences in angular exposure along the longitudinal and transverse axis angles for the three selected targets, the bifurcations of internal carotid and middle cerebral arteries, and the anterior communicating artery (P > 0.05). Except for the distal portion of the operculoinsular compartment of the sylvian fissure, no significant differences in the limits of the surgical exposure through the PT and MPT were apparent on the image-guidance system.

Conclusion: The MPT craniotomy provides comparable surgical exposure to that offered by the PT. The advantages of the MPT include reduction of tissue trauma and bony removal, a decrease in surgical time, and improved cosmetic outcomes.