Prevalence and Clinical Significance of Radiographic Sinus Disease on Preoperative Computed Tomography Imaging in the Endoscopic Skull Base Surgery Population

Introduction Endoscopic skull base surgery (ESBS) provides a safe, minimally invasive approach to treat benign and malignant skull base lesions. The significance of concomitant sinonasal pathology on imaging in patients undergoing ESBS and its effect on perioperative management is not well described. We sought to identify the prevalence and clinical significance of incidentally found radiographic sinus disease on preoperative imaging in patients undergoing ESBS and provide a protocol for management of these patients. Design A retrospective chart review was performed of consecutive patients who underwent ESBS from January 1, 2016 to June 30, 2018. Preoperative computed tomography (CT) scans were reviewed and scored using the Lund-Mackay (LM) staging system. Preoperative nasal endoscopy findings were analyzed. Any preoperative treatment based on these findings and changes in intraoperative management were examined. Results A total of 156 patients (81 women, 74 men) who underwent ESBS were reviewed. The average LM score was 2 ± 2.7 (range: 0–12). A total of 94 patients (60.3%) had evidence of radiographic sinus disease (LM score > 0) and 23 patients (14.7%) had presence of sphenoid sinus disease. Seven patients (4.5%) were treated preoperatively based on CT and/or nasal endoscopy findings. All patients who received preoperative treatment had evidence of sinus disease on imaging with an average score of 4.7 and were evaluated and treated within 1-2 weeks prior to ESBS. One patient had ESBS postponed until endoscopic sinus surgery was performed for extensive chronic rhinosinusitis (CRS) findings on imaging. Conclusion A review of preoperative imaging in patients undergoing ESBS can help identify concurrent sinonasal disease, which has the potential to alter preoperative as well as intraoperative management in these patients. We report a diligent but conservative approach for the treatment of concomitant CRS in the ESBS population with decision for preoperative treatment guided by various factors.

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Transcanal Computed Tomography Views for Transcanal Endoscopic Lateral Skull Base Surgery: Pilot Cadaveric Study

Journal of Neurological Surgery Part B Skull Base ◽

10.1055/s-0039-3400219 ◽

2019 ◽

Author(s):

Rory J. Lubner ◽

Samuel R. Barber ◽

Renata M. Knoll ◽

Judith Kempfle ◽

Daniel J. Lee ◽

...

Keyword(s):

Computed Tomography ◽

Skull Base ◽

Skull Base Surgery ◽

Imaging Study ◽

Preoperative Imaging ◽

Slice Thickness ◽

Imaging Evaluation ◽

Mean Values ◽

Lateral Skull Base ◽

Temporal Bones

Abstract Objectives Transcanal endoscopic operative approaches provide for a minimally invasive surgical portal to the lateral skull base. Traditional preoperative imaging evaluation involves computed tomography (CT) acquisition in the axial and coronal planes that are not optimized for the transcanal surgical corridor. Herein, we describe a novel CT-based “transcanal view” for preoperative surgical planning and intraoperative navigation. Study Design Present study is a cadaveric imaging study. Methods Cadaveric temporal bones (n = 6) from three specimens underwent high-resolution CT (0.625 mm slice thickness). Using three-dimensional (3D) Slicer 4.8, reformatted “transcanal” views in the plane of the external auditory canal (EAC) were created. Axial and coronal reformats were used to compare and measure distances between anatomic structures in the plane of the EAC. Results The degree of oblique tilt for transcanal CT reformats was 6.67 ± 1.78 degrees to align the EAC in axial and coronal planes. Anticipated critical landmarks were identified easily using the transcanal view. Mean values were 8.68 ± 0.38 mm for annulus diameter, 9.5 ± 0.93 mm for isthmus diameter, 10.27 ± 0.73 mm for distance between annulus and isthmus, 2.95 ± 0.13 mm for distance between annulus and stapes capitulum, 5.12 ± 0.35 mm for distance between annulus and mastoid facial nerve, and 19.54 ± 1.22 mm for EAC length. Conclusions This study is the first to illustrate a novel “transcanal” CT sequence intended for endoscopic lateral skull base surgery. Future studies may address how incorporation of a transcanal CT reformat may influence surgical decision making.

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