The natural evolution of endoscopic approaches in skull base surgery: robotic-assisted surgery?

The current surgical trend is to expand the variety of minimally invasive approaches and, in particular, the possible applications of robotic systems in head and neck surgery. This is particularly intriguing in skull base regions. In this paper, we review the current literature and propose personal considerations on the role of robotic techniques in this field. A brief description of our personal preclinical experience on skull base robotic dissection represents the basis for further considerations. We are convinced that the advantages of robotic surgery applied to the posterior cranial fossa are similar to those already clinically experienced in other areas (oropharynx, tongue base), in terms of tremor-free, bimanual, precise dissection: the implementation of instruments for bony work and resolving current drawbacks will definitely increase the applicability of such a system in forthcoming years

Extended endoscopic endonasal transsphenoidal approach to the suprasellar area: Anatomic considerations - Part I

INTRODUCTION: Interest in using the extended endonasal transsphenoidal approach for management of suprasellar lesions, with either a microscopic or endoscopic technique, has increased in recent years. The most relevant benefit is that this median approach permits the exposure and removal of suprasellar lesions without the need for brain retraction. MATERIALS AND METHODS: Fifteen human cadaver heads were dissected to evaluate the surgical key steps and the advantages and limitations of the extended endoscopic endonasal transplanum sphenoidale approach. We compared this with the transcranial microsurgical view of the suprasellar area as explored using the bilateral subfrontal microsurgical approach, and with the anatomy of the same region as obtained through the endoscopic endonasal route. RESULTS: Some anatomic conditions can prevent or hinder use of the extended endonasal approach. These include a low level of sphenoid sinus pneumatization, a small sella size with small distance between the internal carotid arteries, a wide intercavernous sinus, and a thick tuberculum sellae. Compared with the subfrontal transcranial approach, the endoscopic endonasal approach offers advantages to visualizing the subchiasmatic, retrosellar, and third ventricle areas. CONCLUSION: The endoscopic endonasal transplanum sphenoidale technique is a straight, median approach to the midline areas around the sella that provides a multiangled, close-up view of all relevant neurovascular structures. Although a lack of adequate instrumentation makes it impossible to manage all structures that are visible with the endoscope, in selected cases, the extended endoscopic endonasal approach can be considered part of the armamentarium for surgical treatment of the suprasellar area

Symmetrical anatomical variant of the anterior belly of the digastric muscle: clinical implicat

The digastric muscle is an important surgical landmark. Several anatomical variants of the digastric muscle are reported in literature and, in particular, the presence of accessory anterior bellies of the muscle is not uncommon. Here, an unreported symmetrical variant of the digastric muscle was found during a dissection of the suprahyoid region. The dissection showed digastric muscles with an accessory anterior belly, which originated from the anterior belly of muscles in proximity and anteriorly to the intermediate tendon. The accessory bellies were fused together on the midline and were attached with a unique tendon to the inner surface of the mental symphysis. These muscles completely filled the submental triangle. This unreported anatomical variant could be considered an additional contribution to description of the anatomical variants of the digastric muscle, with several implications in head and neck pathology, diagnosis and surgery.

A 3-dimensional transnasal endoscopic journey through the paranasal sinuses and adjacent skull base: a practical and surgery-oriented perspective

An endoscopic approach through the transnasal corridor is currently the treatment of choice in the management of benign sinonasal tumors, cerebrospinal fluid leaks, and pituitary lesions. Moreover, this approach can be considered a valid option in the management of selected sinonasal malignancies extending to the skull base, midline meningiomas, parasellar lesions such as craniopharyngioma and Rathke cleft cyst, and clival lesions such as chordoma and ecchordosis. Over the past decade, strict cooperation between otorhinolaryngologists and neurosurgeons and acquired surgical skills, together with high-definition cameras, dedicated instrumentation, and navigation systems, have made it possible to broaden the indications of endoscopic surgery. Despite these improvements, depth perception, as provided by the use of a microscope, was still lacking with this technology. The aim of the present project is to reveal new perspectives in the endoscopic perception of the sinonasal complex and skull base thanks to 3-dimensional endoscopes, which are well suited to access and explore the endonasal corridor. In the anatomic dissection herein, this innovative device came across with sophisticated and long-established fresh cadaver preparation provided by one of the most prestigious universities of Europe. The final product is a 3-dimensional journey starting from the nasal cavity, reaching the anterior, middle, and posterior cranial fossae, passing through the ethmoidal complex, paranasal sinuses, and skull base. Anatomic landmarks, critical areas, and tips and tricks to safely dissect delicate anatomic structures are addressed through audio comments, figures, and their captions

The myloglossus in a human cadaver study: common or uncommon anatomical structure?

Background: Additional extrinsic muscles of the tongue are reported in literature and one of them is the myloglossus muscle (MGM). Since MGM is nowadays considered as anatomical variant, the aim of this study is to clarify some open questions by evaluating and describing the myloglossal anatomy (including both MGM and its ligamentous counterpart) during human cadaver dissections. Materials and methods: Twenty-one regions (including masticator space, sublingual space and adjacent areas) were dissected and the presence and appearance of myloglossus were considered, together with its proximal and distal insertions, vascularisation and innervation. Results: The myloglossus was present in 61.9% of cases with muscular, ligamentous or mixed appearance and either bony or muscular insertion. Facial artery provided myloglossal vascularisation in the 84.62% and lingual artery in the 15.38%; innervation was granted by the trigeminal system (buccal nerve and mylohyoid nerve), sometimes (46.15%) with hypoglossal component. Conclusions: These data suggest us to not consider myloglossus as a rare anatomical variant.

Combined presence of ophthalmic artery origin from anterior cerebral artery and meningolacrimal artery

In this study we describe a case of an ophthalmic artery (OphA) originating from the pre-communicating segment of the anterior cerebral artery (A1), associated with the presence of a meningolacrimal artery (MLA). The OphA has an anomalous origin in 1-3% of cases and rarely arises from A1, however, the combination of these anatomical variations is unique. Anomalous origins of the OphA are also correlated with a higher incidence of ICA aneurysm (1). Macroscopic and endonasal endoscopic dissections of a cadaver head, which formerly underwent a cone-beam CT scan, were performed. Bilateral samples of the ICA walls were collected and processed for standard hematoxylin-eosin staining and immunofluorescence analysis. The MLA was found on the right side by CT scan and its entrance in the superior orbital fissure was confirmed during head dissection. Hence, performing the endoscopic approach on the same side, the anomalous OphA, originating from the inferior surface of A1 segment and entering the optic canal above the optic nerve, was discovered. This arterial pattern could be explained by the embryological development of the orbital vascular system and it is referred to persistent ventral OphA (2). The histomorphological examination of ICA walls showed a significantly decreased thickness of the tunica media and adventitia on the right side compared to the left one. In addition, fluores- cence microscopy showed that type I and type III collagen were significantly lower in the tunicae media and adventitia of the right side. Since aneurysms of the ICA are related with a low content of collagen in the arterial wall, our results are consistent with current literature