Application of ultrasonic bone curette in endoscopic endonasal skull base surgery: technical note

Abstract

Background Endoscopic endonasal surgery (EES) of the skull base often requires extensive bone work in proximity to critical neurovascular structures. Objective To demonstrate the application of an ultrasonic bone curette during EES. Methods Ten patients with skull base lesions underwent EES from September 2011 to April 2012 at the University of Pittsburgh Medical Center. Most of the bone work was done with high-speed drill and rongeurs. The ultrasonic curette was used to remove specific structures. Results All the patients were submitted to fully endoscopic endonasal procedures and had critical bony structures removed with the ultrasonic bone curette. Two patients with degenerative spine diseases underwent odontoid process removal. Five patients with clival and petroclival tumors underwent posterior clinoid removal. Two patients with anterior fossa tumors underwent crista galli removal. One patient underwent unilateral optic nerve decompression. No mechanical or heat injury resulted from the ultrasonic curette. The surrounding neurovascular structures and soft tissue were preserved in all cases. Conclusion In selected EES, the ultrasonic bone curette was successfully used to remove loose pieces of bone in narrow corridors, adjacent to neurovascular structures, and it has advantages to high-speed drills in these specific situations.

Keywords: bone removal; endoscopic endonasal; skull base; ultrasonic bone curette.

Fig. 1

(A) The extra-long handpiece of Sonopet for endoscopic endonasal surgery. (B) The three different tips used for bone removal (left to right): the Open Angle Claw, the Micro Claw, and the Payner 360°. (C) A lateral view to demonstrate the difference between the Micro (left) and the Open Angle (right), both with a one-side cutting surface.

Fig. 2

(A) Preoperative sagittal computed tomography scan demonstrating the separation of the odontoid process from the body of the axis. (B) Extended endoscopic endonasal approach to resection of the odontoid process. The Payner 360° is used after removing the anterior arch of C1. (C) Postoperative image demonstrating removal of the odontoid process.

Fig. 3

(A) Preoperative axial magnetic resonance imaging scan demonstrating a right-sided petroclival meningioma compressing the brainstem. (B) Endoscopic endonasal transclival approach. The Micro Claw is used to remove the right posterior clinoid. (C) Postoperative image demonstrating partial resection of the lesion and recovery from brainstem compression. ICA, internal carotid artery; Pit. Gland, pituitary gland; Post. Clin., posterior clinoid).

Fig. 4

(A) Preoperative coronal magnetic resonance imaging scan demonstrating a right-sided olfactory groove meningioma. (B) Endoscopic endonasal uninarial approach. The Micro Claw is used to remove the crista galli. (C) Postoperative image demonstrating gross total resection of the lesion. Cr, crista; Olf. Sulc., olfactory sulcus; Periorb., periorbita.

Fig. 5

(A) Preoperative axial computed tomography scan demonstrating a fibrous dysplasia of the left orbit including the optic canal. (B) Endoscopic endonasal uninarial approach. The Micro Claw is used to remove the optic canal roof. (C) Postoperative image demonstrating decompression of the optic canal. CN, cranial nerve; Op. Can., optic canal.