The Current State of Visualization Techniques in Endoscopic Skull Base Surgery

Abstract

Skull base surgery has undergone significant progress following key technological developments. From early candle-lit devices to the modern endoscope, refinements in visualization techniques have made endoscopic skull base surgery (ESBS) a standard practice for treating a variety of conditions. The endoscope has also been integrated with other technologies to enhance visualization, including fluorescence agents, intraoperative neuronavigation with augmented reality, and the exoscope. Endoscopic approaches have allowed neurosurgeons to reevaluate skull base neuroanatomy from new perspectives. These advances now serve as the foundation for future developments in ESBS. In this narrative review, we discuss the history and development of ESBS, current visualization techniques, and future innovations.

Keywords: neuro-oncology; neuroendoscopy; neuronavigation; skull base surgery; ultrasonography.

Figure 1

(a) Examples of instruments used for excerebration in Ancient Egypt. Reprinted/adapted with permission from Ref. [12]. 2022, Wellcome Collection. (b) Lamp-lit endoscope designed by Desormeaux. Reprinted/adapted with permission from Ref. [12]. 1891, Lea Brothers & Company. (c) Current endoscopic endonasal operating room suite at the Cleveland Clinic. The high-definition surgical endoscope setup improves visualization and ergonomics for two simultaneous surgeons. Reprinted/adapted with permission from Ref. [12]. 2022, Pablo F. Recinos, M.D.

Figure 2

Light sources from high to low heat production. Incandescent lightbulbs produce more heat (red) than LED light sources (blue). LED: light emitting diode. Reprinted/adapted with permission from Ref. [18]. 2022, Erion Junior de Andrade, M.D., M.Sc.

Figure 3

Graph of the ability of the human eye to perceived screen resolution based on screen size (x-axis) and distance from monitor (y-axis). Reprinted/adapted with permission from Ref. [21]. 2022, Carlton Bale, M.S., M.B.A.

Figure 4

Preoperative planning with the Stryker Scopis neuronavigation system (Stryker Corporation, Kalamazoo, MI, USA). This system utilizes “building blocks” technology to highlight designated anatomical landmark. Reprinted/adapted with permission from Ref. [25]. 2022, Stryker Corporation.

Figure 5

Augmented reality superimposed onto live endoscopic video with the Stryker Scopis navigation system (Stryker Corporation, Kalamazoo, MI, USA). Reprinted/adapted with permission from Ref. [25]. 2022, Stryker Corporation.

Figure 6

Augmented reality with live endoscopic video during ESBS to highlight the location of the basilar and internal carotid arteries. Augmented reality with the Stryker Scopis navigation system (Stryker Corporation, Kalamazoo, MI, USA). Reprinted/adapted with permission from Ref. [25]. 2022, Stryker Corporation.

Figure 7

(a) Fujifilm pituitary guidance transducer (Fujifilm Healthcare Americas Corporation, Twinsburg, OH, USA). (b) Intraoperative Doppler ultrasonography showing a pituitary tumor and the cavernous segment of the internal carotid artery (ICA) before tumor debulking. (c) Intraoperative Doppler ultrasonography showing a pituitary tumor and the cavernous segment of the ICA after tumor resection. Reprinted/adapted with permission from Ref. [57]. 2022, Fujifilm Corporation.

Figure 8

The cavernous sinus spaces and the cavernous segment of the internal carotid artery (ICA) from imaging, microsurgical transcranial and endoscopic endonasal perspectives. (a) Angiogram, lateral view of the ICA. (b) CT angiogram, lateral view of the ICA. The relationship of the ICA with the sphenoid bone is observed. (c) Cadaveric dissection demonstrating a superolateral view of the middle fossa and ICA via a transcranial approach. (d) Cadaveric dissection demonstrating an endoscopic endonasal view of the relationship of the cavernous ICA with the nerves on the lateral wall of the cavernous sinus. Reprinted/adapted with permission from Ref. [18]. 2022, Erion Junior de Andrade, M.D., M.Sc.

Figure 9

The surgical exoscope in use during a neuro-surgical procedure. Reprinted/adapted with permission from Ref. [12]. 2022, Pablo F. Recinos, M.D.