Preliminary experience with 4K ultra-high definition endoscope: analysis of pros and cons in skull base surgery

Abstract

During the last two decades endoscopic skull base surgery observed a continuous technical and technological development 3D endoscopy and ultra High Definition (HD) endoscopy have provided great advances in terms of visualisation and spatial resolution. Ultra-high definition (UHD) 4K systems, recently introduced in the clinical practice, will shape next steps forward especially in skull base surgery field. Patients were operated on through transnasal transsphenoidal endoscopic approaches performed using Olympus NBI 4K UHD endoscope with a 4 mm 0° Ultra Telescope, 300 W xenon lamp (CLV-S400) predisposed for narrow band imaging (NBI) technology connected through a camera head to a high-quality control unit (OTV-S400 - VISERA 4K UHD) (Olympus Corporation, Tokyo, Japan). Two screens are used, one 31" Monitor - (LMD-X310S) and one main ultra-HD 55" screen optimised for UHD image reproduction (LMD-X550S). In selected cases, we used a navigation system (Stealthstation S7, Medtronic, Minneapolis, MN, US). We evaluated 22 pituitary adenomas (86.3% macroadenomas; 13.7% microadenomas). 50% were not functional (NF), 22.8% GH, 18.2% ACTH, 9% PRL-secreting. Three of 22 were recurrences. In 91% of cases we achieved total removal, while in 9% near total resection. A mean follow-up of 187 days and average length of hospitalisation was 3.09 ± 0.61 days. Surgical duration was 128.18± 30.74 minutes. We experienced only 1 case of intraoperative low flow fistula with no further complications. None of the cases required any post- or intraoperative blood transfusion. The visualisation and high resolution of the operative field provided a very detailed view of all anatomical structures and pathologies allowing an improvement in safety and efficacy of the surgical procedure. The operative time was similar to the standard 2D HD and 3D procedures and the physical strain was also comparable to others in terms of ergonomics and weight.

Keywords: 4K; Endoscopic sinus surgery; Endoscopy; Skull base; Ultra-high definition.

Fig. 1.

Endoscopic view (A) of the sellar phase using the 4K Olympus endoscope in a case of not secreting macroadenoma as observed in MRI (C). The magnified view (B) allowed a correct discrimination of the details and chromatic differences between normal pituitary (p) tissue versus adenoma (a) the different layers of dura (d) and the texture of the pathologic tissue.

Fig. 2.

Endoscopic view (A) of the sellar phase using the 4K Olympus endoscope in a case of GH secreting macroadenoma as showed in the MRI (D). The magnified view allowed a correct discrimination of the details and chromatic differences between normal pituitary tissue versus adenoma, starting from the initial phases before opening the dura (B-C). After tumour removal the great detailed resolution allowed the correct evaluation of the normal pituitary gland (p), the meningohypophiseal arteries and the pituitary stalk (ps) leading to a complete removal of the pathologic tissues and exposure of the dura of the dorsum sellae (ds).

Fig. 3.

Endoscopic view of the field after complete removal of the macroadenoma (A) showing the suspect quite small residual disease (arrows and circles) that clearly appears with magnification at high resolution (B) but seems to be confirmed using NBI filter (C,D), even if further experience and studies are necessary.