En-bloc craniotomy for the pre-sigmoid infra- and supratentorial approach: technical note

Introduction The combined supra-infratentorial approach as described some 30 years ago is to date considered a standard procedure for skull base procedures. Several variants have been devised, including preservation of the mastoid process. We herein present the cosmetically most sophisticated and fastest solution. Objectives The authors describe an en bloc supra- and infratentorial pre-sigmoid combined approach. This variant of surgical technique involves a one-piece bone flap (temporal-suboccipital-mastoideal flap). We present another variant of craniotomy for the combined supra- and infratentorial pre-sigmoid approach that preserves the mastoid process and thus appears to be cosmetically much more acceptable. Materials and methods Eight dry cadaveric skulls were used to develop an ideal one-piece excision of the cranial vault across the transverse sinus, including portions of the mastoid. Our aim was that no further drilling of the basal skull was needed. The procedure thereafter was practiced on a fresh prepared cadaveric specimen where its feasibility was again confirmed and was then applied to a patient suffering from a huge petroclival meningioma. It was very well tolerated and produced an excellent long-term cosmetic result. Discussion The combined supra- and infratentorial pre-sigmoid approach offers the possibility of resecting complex petroclival lesions. The variant presented herein is less time consuming than previously described methods and probably offers the best possible cosmetic result. Conclusion The en-bloc cranioplastic approach with preservation of the mastoid process is a new, interesting variant of a classical technique that is easy to perform and has the intention of achieving the best possible cosmetic result.