Davide Lancini

Modular Endoscopic Medial Maxillectomies: Quantitative Analysis of Surgical Exposure in a Preclinical Setting.

BACKGROUND The nomenclature adopted for endoscopic medial maxillectomies (EMMs) is exceedingly heterogeneous. The aim of this study was to objectively measure surgical exposure in a preclinical anatomic setting to validate a classification for modular EMMs. MATERIALS AND METHODS Computed tomography was used to scan 6 cadaver heads, and images were uploaded on dedicated software. A neuronavigation system was used to measure areas and volumes of surgical corridors during dissection. Differences of >10% of area exposed and >3 cm3 of volume were considered to define incremental types of EMM. Specific anatomic targets were assessed on the axial and sagittal planes. Influence of anatomic variants on surgical exposure was evaluated. RESULTS There were 4 types of EMMs (A-D), with a transseptal variant for each, identified. In the axial plane, type A exposed the vidian canal and foramen rotundum, type B exposed the foramen ovale and foramen spinosum, and transseptal type C or type D exposed the coronoid process. In the sagittal plane, type A exposed the vidian canal, and type B exposed the foramen ovale and styloid process. Transseptal type C exposed the pterygomaxillary fissure, and type D exposed the inferior border of the lateral pterygoid plate. The nasal floor limits the downward angle in transseptal approaches. The width of the piriform aperture independently influenced surgical volume of types B and C. CONCLUSIONS This modular classification of EMMs, based on quantitative analysis in a preclinical setting, should allow for better personalized preoperative surgical planning and provides standardization of nomenclature.

Agger-bullar classification (ABC) of the frontal sinus drainage pathway: validation in a preclinical setting.

The anatomy of structures surrounding the frontal sinus drainage pathway (FSDP) is extremely complex and challenging for endoscopic sinus surgeons. The anatomical nomenclature of this area reflects this complexity and lack of agreement regarding anatomical variants of this region is present in the literature. This work presents a new classification system of the air spaces surrounding the FSDP, called the agger‐bullar classification (ABC), and compares it with the most widely used anatomical classification of the frontoethmoidal region, the modified Bent and Kuhn classification (MBKC).

Anterior superior alveolar nerve injury after extended endoscopic medial maxillectomy: a preclinical study to predict neurological morbidity

Endoscopic medial maxillectomies (EMMs) are used to optimize exposure of the maxillary sinus and retromaxillary areas. Although in type D EMM (Sturmann‐Canfield procedure) the anterior superior alveolar nerve (ASAN) is always at risk of injury, only 29% of patients complained of alveolar process and dental anesthesia. The purpose of this anatomical study is to assess the neural anastomotic network of the ASAN (ASAN‐NAN) and describe different extensions of type D EMMs in a preclinical setting.

The turbinal flap: an additional option for anterior skull base reconstruction. Cadaveric feasibility study and case report

Over the past decade, the treatment of complex intradural and extradural pathologies via expanded endonasal approaches has been made possible by progresses and refinements in skull base reconstruction techniques. The aim of this anatomic study is to describe a novel endonasal flap, the turbinal flap (TF), based on the middle and superior turbinate mucosa and pedicled on the ethmoidal arteries system.

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.

Symmetrical anatomical variant of the anterior belly of the digastric muscle: clinical implications.

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.

Transnasal Endoscopic and Lateral Approaches to the Clivus: A Quantitative Anatomic Study.

BACKGROUND Transnasal endoscopic approaches to the clivus have been established recently. Comparative analyses with classic lateral approaches are limited. In this study, we compared transnasal endoscopic and lateral approaches to the clivus, quantifying the exposure and working volume of each approach in the anatomy laboratory. METHODS High-resolution computed tomography scans were performed on 5 injected specimens (10 sides). In each specimen, transnasal endoscopic approaches (i.e., paraseptal, transrostral, extended transrostral, transethmoidal, and extended transclival without and with intradural hypophysiopexy) and lateral approaches (i.e., retrosigmoid, far-lateral, presigmoid retrolabyrinthine and translabyrinthine) to the clivus were performed. An optic neuronavigation system and dedicated software (ApproachViewer; Guided Therapeutics Program, University Health Network, Toronto, Ontario, Canada) were used to quantify the working volume and exposed clival area of each approach. Statistical evaluation was performed with the Kruskal-Wallis test and Steel-Dwass-Critchlow-Fligner post hoc test. RESULTS Endoscopic transnasal transclival approaches showed higher working volume and larger clival exposure compared with lateral approaches. Incremental volumetric values were evident for transnasal approaches; presigmoid approaches provided less working volume than retrosigmoid approaches. A transnasal transclival approach with hypophysiopexy provided significant exposure of the upper clivus (84.4%). The transrostral approach was the first transnasal approach providing satisfactory access to the midclivus (66%); retrosigmoid and far-lateral approaches provided exposure of approximately one half of the midclivus. The lower clivus was optimally exposed with endoscopic transclival approaches (83%), whereas access to this region was limited with lateral approaches. CONCLUSIONS This quantitative anatomic study shows that endoscopic transnasal approaches to the clivus provide a larger working volume and wider exposure of the clivus compared with lateral approaches.

Long-term outcomes and prognosis in submandibular gland malignant tumors: A multicenter study: Outcomes and Prognosis in SMGTs

Submandibular gland tumors (SMGTs) are rare and characterized by heterogeneity in histologic profiles. The aim of the present study was to retrieve data on submandibular gland (SMG) malignancies and identify factors influencing survival.

Anatomical Cadaver Study of Endolaryngeal Vascularization: Focus on the Glottis, Supraglottis, and Subglottis From the Transoral Microsurgical Point of View

Introduction Carbon dioxide laser coagulation during transoral laser microsurgery (TLM) for laryngeal cancer allows control of bleeding from vessels smaller than 0.5 mm. Therefore, larger arteries and veins must be carefully managed by clipping and/or monopolar cautery. The aim of this paper is to detail endolaryngeal vascular anatomy and identify areas of possible bleeding during TLM. Methods We performed an anatomical study on a series of 11 fresh-frozen human cadavers. After injection of a bicomponent red silicone into the innominate, left common carotid, and left subclavian arteries, 22 hemilarynges were dissected, the course of the supraglottic, glottic, and subglottic vessels were traced after microdissection of the intervening structures, and their size measured at specific landmark points where such vessels are more frequently encountered during TLM. Results Three vessels arising from the superior laryngeal artery were identified after its entry point at the level of the thyro-hyoid membrane: (1) the epiglottic artery (EA), documented in 100% of cases, a common trunk dividing into two main vessels (2) the postero-inferior artery (PIA), present in 100% of the specimens, running downward and dividing in a posterior (pPIA), and anterior (aPIA) branches (3) the antero-inferior artery (AIA), present in 95% of our specimens, running downward to the anterior commissure (AC). Two transverse anastomotic networks (TANs) connected the AIA and PIA, both parallel to the vocal muscle, one lateral (present in 100% of cases), and another medial (91% of specimens). Finally, a fourth vessel supplying the glottic plane was found to be the endolaryngeal paracommissural branch of the crico–thyroid artery (PCA), arising from the inferior laryngeal artery and emerging just below the AC, through the crico–thyroid membrane (reported in 100% of the specimens). This vessel anastomosed in 91% of cases with the AIA, through one or both of the TANs. Conclusion The course of the endolaryngeal arteries, their relationships with adjacent structures, and size at specific landmark points have been herein described in order to provide surgeons with a map to guide them during the steep learning curve of transoral surgery of the larynx, with special emphasis given to TLM.

The frontoethmoidal architecture: a developmental point of view

The anatomy of frontal sinus drainage pathway (FSDP) and surrounding spaces is extremely complex and variable. Its anatomical variability can be simplified based on the knowledge of the developmental mechanism of the frontal recess. The frontal sinus develops from the 13th week of intrauterine life to the age of twenty through a number of well-known steps of progressive extension within the frontal bone. Its development results from an upward epithelial migration of the anterior ethmoidal cells that penetrate the inferior aspect of the frontal bone between its two diploic plates. Even though this developmental theory is almost universally accepted, only few Authors focused on the formation of FSDP prior to the extramural pneumatization (1-2). The results of the present study conducted on 14 human heads match with the developmental model proposed by Terracol and Ardouin (2), in fact a number of significant associations are conform to the process of growing of the frontal sinus from one out of the three primordial cells (i.e. orbital, nasal, or bullar cell). In this model, renewed in view of the observation of the present study, the hierarchical order of growing among primordial cells determines the final frontoethmoidal architecture.