Skull Base Invasion Patterns of Malignant Head and Neck Tumors: A Neurosurgical Perspective

Combined Exoscopic and Endoscopic Technique for Craniofacial Resection

We determined the feasibility of the combined exoscopic-endoscopic technique (CEE) as an alternative to the microscope in craniofacial resection (CFR). This retrospective study was conducted at a single institution and included eight consecutive patients with head and neck tumors who underwent CFR between September 2019 and July 2021. During the transcranial approach, microsurgery was performed using an exoscope in the same manner as in traditional microscopic surgery, and an endoscope was used at the blind spot of the exoscope. The exoscope provided images of sufficient quality to perform microsurgery, while the sphenoid sinus lumen was the blind spot of the exoscope during anterior (n = 3) and anterolateral CFR (n = 2), and the medial aspect of the temporal bone was the blind spot of the exoscope during temporal bone resection (n = 2). These blind spots were visualized by the endoscope to facilitate accurate transection of the skull base. The advantages of the exoscope and endoscope include compact size, ergonomics, surgical field accessibility, and equal visual experience for neurosurgeons and head and neck surgeons, which enabled simultaneous transcranial and transfacial surgical procedures. All the surgeries were successful without any relevant complications. CEE is effective in transcranial skull base surgery, especially CFR involving simultaneous surgical procedures.

Surgical Classification of Radical Temporal Bone Resection and Transcranial Tympanotomy: A Retrospective Study from the Neurosurgical Perspective

OBJECTIVE

To review the authors' surgical experience with radical temporal bone resection (TBR) with an emphasis on the classification of skull base osteotomy and transcranial tympanotomy (TCT) that is required for middle ear transection.

METHODS

We reviewed the records of 25 patients who underwent radical TBR at our facilities between 2011 and 2020.

RESULTS

The osteotomy line of radical TBR was divided into 3 segments: anterior (A), medial (M), and posterior (P). Each segment was further classified as follows: A1, through the glenoid fossa (1 patient); A2, in front of the glenoid fossa (23 patients); A3, through the greater wing of the sphenoid bone (1 patient); M1, through the middle ear (16 patients); M2, through the inner ear (9 patients); P1, through the mastoid (9 patients); and P2, through the posterior cranial fossa (16 patients). The M segment was significantly associated with operation time and intraoperative blood loss. In all patients with M1 osteotomy, TCT was performed; TCT was classified into superior and far posterior approaches. A superior approach was performed in all 16 patients, whereas the far posterior approach was performed in only 7 patients with both M1 and P2 osteotomy.

CONCLUSIONS

Our newly proposed osteotomy classification of radical TBR is suitable for minute but clinically important adjustment of the osteotomy line. TCT is an indispensable technique for M1 osteotomy; our newly proposed classification expands our understanding of TCT and how to incorporate this technique into radical TBR.