Patologie della base-cranica anteriore con Piezosurgery

.PIEZOSURGERY\uae Stato dell\u2019arte e prospettive Chirurgia Cranio Facciale Neurochirurgi

Basic and advanced endoscopic sinus surgery course: open and endoscopic cadaver dissection techniques and live surgery.

This course originates from the close collaboration experienced and established over many years between the three professionals most involved in the surgical treatment of lesions of the anterior skull base. We believe, and the results have proved us right, that the achievement of the best treatment in such complex anatomical regions can be born only from an accurate preoperative study, the realization of several surgical procedures and the care of every detail during the post-operative period carried out in a close collaboration among Otolaryngologists, Maxilo-Facial surgeons and Neurosurgeons. The relatively recent introduction of endoscopic surgery and the huge expansion of the latter has further expanded the possibilities of collaboration. On the other hand those who want to approach to this type of pathologies necessarily have to know not only the techniques and possibilities of endoscopy but also the open techniques which are essential to face certain situations or clinical manifestations. The experience of many years of shared work between two surgical university schools with great traditions such as Modena and Verona besides a personal friendship established over time has enabled us both to joint the three specialties and to create a group that is inspired by the same principles

A comparative in vivo evaluation of bioactive glasses and bioactive glass-based composites for bone tissue repair

In this work a set of novel materials for bone tissue regeneration have been tested in vivo in an animal model. In fact, despite many studies have been devoted to amorphous 45S5 Bioglass®, there is lack in the literature of works aimed to study the in vivo performance of heat-treated – and thus partially crystallized – 45S5. As widely reported, crystallization limits the bioactivity of 45S5 and is the main reason that prevents a broader use of this material. Thus, in the present work, a recently developed bioactive glass (BG_Ca/Mix) is tested, since previous investigations demonstrated that BG_Ca/Mix is particularly promising by virtue of both its high bioactivity and lower tendency to crystallize with respect to 45S5. BG_Ca/Mix sintered powders and two composites, which contain BG_Ca/Mix and an increasing percentage (20 wt% or 70 wt%) of hydroxyapatite (HA), were considered. As a term of comparison, 45S5 sintered powders were also studied. The samples were implanted in rabbits' femurs and harvested after 8 weeks. The histological analysis demonstrated that BG_Ca/Mix has an osteoconductive ability slightly higher than that of 45S5 glass-ceramics, followed by that of the composites, which may represent the starting point for obtaining systems with degradation rate tailored for a given clinical application. Moreover, the 45S5 samples were locally cracked, probably because of a non-uniform dissolution in the physiological environment. On the contrary such cracks, which could lead to implant instability and unsuitable mechanical performance, were not observed in BG_Ca/Mix

From Osteoclast Differentiation to Osteonecrosis of the Jaw: Molecular and Clinical Insights

Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte colony-stimulating factor (M-CSF) and receptor activator of NFκB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect space–time coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Paget’s disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures.Bone physiology relies on the delicate balance between resorption and formation of its tissue. Bone resorption depends on a process called osteoclastogenesis in which bone-resorbing cells, i.e., osteoclasts, are produced by the differentiation of more undifferentiated progenitors and precursors. This process is governed by two main factors, monocyte colony-stimulating factor (M-CSF) and receptor activator of NFκB ligand (RANKL). While the former exerts a proliferating effect on progenitors/precursors, the latter triggers a differentiation effect on more mature cells of the same lineage. Bone homeostasis requires a perfect space–time coordination of the involved signals. When osteoclastogenesis is poorly balanced with the differentiation of the bone forming counterparts, i.e., osteoblasts, physiological bone remodelling can turn into a pathological state, causing the systematic disruption of bone tissue which results in osteopenia or osteolysis. Examples of these conditions are represented by osteoporosis, Paget’s disease, bone metastasis, and multiple myeloma. Therefore, drugs targeting osteoclastogenesis, such as bisphosphonates and an anti-RANKL monoclonal antibody, have been developed and are currently used in the treatment of such diseases. Despite their demonstrated therapeutic efficacy, these agents are unfortunately not devoid of side effects. In this regard, a condition called osteonecrosis of the jaw (ONJ) has been recently correlated with anti-resorptive therapy. In this review we will address the involvement of osteoclasts and osteoclast-related factors in the pathogenesis of ONJ. It is to be hoped that a better understanding of the biological mechanisms underlying bone remodelling will help in the design a medical therapeutic approach for ONJ as an alternative to surgical procedures

Cell Proliferation to Evaluate Preliminarily the Presence of Enduring Self-Regenerative Antioxidant Activity in Cerium Doped Bioactive Glasses

(1) Background: a cell evaluation focused to verify the self-regenerative antioxidant activity is performed on cerium doped bioactive glasses. (2) Methods: the glasses based on 45S5 Bioglass®, are doped with 1.2 mol%, 3.6 mol% and 5.3 mol% of CeO2 and possess a polyhedral shape (~500 µm2). Glasses with this composition inhibit oxidative stress by mimicking catalase enzyme (CAT) and superoxide dismutase (SOD) activities; moreover, our previous cytocompatibility tests (neutral red (NR), 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Bromo-2-deoxyUridine (BrdU)) reveal that the presence of cerium promotes the absorption and vitality of the cells. The same cytocompatibility tests were performed and repeated, in two different periods (named first and second use), separated from each other by four months. (3) Results: in the first and second use, NR tests indicate that the presence of cerium promotes once again cell uptake and viability, especially after 72 h. A decrease in cell proliferation it is observed after MTT and BrdU tests only in the second use. These findings are supported by statistically significant results (4) Conclusions: these glasses show enhanced proliferation, both in the short and in the long term, and for the first time such large dimensions are studied for this kind of study. A future prospective is the implantation of these bioactive glasses as bone substitute in animal models

Linfadenectomia sovraomoioidea.

Lo svuotamento linfonodale sovra-omoioideo è la dissezione laterocervicale selettiva più frequentemente eseguita in caso di carcinoma del cavo orale. Con il termine “svuotamento linfonodale selettivo” si intende l’asportazione dei pacchetti linfonodali a maggior rischio di metastasi, con la preservazione di uno o più livelli linfonodali di solito rimossi durante uno svuotamento radicale. In particolar modo lo svuotamento sovraomoioideo prevede la dissezione del I-II-III livello linfonodale (ovvero al di sopra, cranialmente, rispetto al muscolo omoioideo). La possibilità di eseguire dissezioni selettive del collo si basa sul fatto che il drenaggio linfatico delle mucose del cavo orale, in pazienti con carcinoma a cellule squamose precedentemente non trattati, segue percorsi relativamente costanti e di conseguenza le metastasi linfonodali presentano un pattern di diffusione relativamente prevedibile in base alla localizzazione del tumore primitivo. Gli studi anatomici di Rouvière, Fish e Sigel (e successivamente Shah) hanno concluso che i tumori della cavità orale metastatizzano più frequentemente ai linfonodi del collo del I, II, e III livello, mentre i tumori dell’orofaringe, ipofaringe, laringe metastatizzano più frequentemente al II, III, e IV livello. Il trattamento chirurgico delle metastasi linfonodali è stato proposto ed eseguito in origine da Von Albrecht nel 1875, ai primordi della chirurgia laringea, con la sola asportazione dei linfonodi metastatici; Gluck e Sorensen asportavano anche il muscolo sternocleidomastoideo, la giugulare interna e, talvolta, la carotide. Crile nel 1898 introdusse lo svuotamento linfonodale sistematico in monoblocco con la laringectomia, dimostrando che nella sua casistica i malati così trattati sopravvivevano mediamente quattro volte di più di quelli trattati con semplice laringectomia. In seguito, circa 70 anni dopo, Suarez e Bocca iniziarono a conservare il nervo spinale accessorio, la vena giugulare interna e il muscolo sternocleidomastoideo in caso di tumori della laringe e ipofaringee con collo clinicamente negativo per localizzazioni metastatiche linfonodali. L’origine dello svuotamento selettivo, invece, non è del tutto chiara. Molti chirurghi hanno usato questo tipo di procedura per decadi senza descriverla formalmente. Per esempio, Kocher eseguiva un’asportazione parziale dei linfonodi nei pazienti con carcinoma del cavo orale e collo N0 già alla fine del diciannovesimo secolo. Con il tempo si diffuse una procedura detta “svuotamento sovraioideo” (cioè del I livello) nei casi di linfoadenopatie occulte associate ai carcinomi soprattutto del labbro. In seguito, nel 1972, Lindberg ha dimostrato che i livelli più frequentemente coinvolti in pazienti con carcinoma del cavo orale sono in genere il II e il III; nei carcinomi del pavimento della bocca e della lingua mobile il livello più frequentemente coinvolto è, invece, il I. Più tardi Byers propose i termini “anteriore” e “sovraomoioideo” per indicare le dissezioni parziali, ma solo nel 1991 si iniziò ad usare il termine selettivo per descrivere le resezioni linfonodali limitate (Academy’s Committee for Head and Neck Surgery and Oncology). In generale lo svuotamento linfonodale laterocervicale del collo può essere eseguito secondo due diversi tempi rispetto al momento dell’asportazione del tumore primario: 1) in contemporanea all’asportazione del tumore primario ed in assenza di evidenza clinica e radiologica di metastasi linfonodali laterocervicali, ovvero in stadio cN0, al fine di eradicare eventuali metastasi occulte: viene definito svuotamento elettivo o elective neck dissection. 2) successivamente all‘intervento sul tumore primario, al manifestarsi clinico o radiologico delle metastasi linfonodali laterocervicali: viene definito svuotamento terapeutico o therapeutic neck dissection. Lo svuotamento linfonodale elettivo (cN0) è abitualmente di tipo selettivo. Lo svuotamento selettivo del collo per il carcinoma del cavo orale comprende i livelli I-III ed è altrimenti denominato svuotamento linfonodale laterocervicale sovra-omoioideo. La “depth of invasion” (DOI) è ad oggi il miglior fattore per ipotizzare la presenza di metastasi linfonodali occulte laterocervicali e quindi decidere se attuare uno svuotamento linfonodale laterocervicale elettivo (cN0) o terapeutico (al manifestarsi delle metastasi linfonodali cN+). Per carcinomi con una DOI maggiore ai 4mm, si deve programmare uno svuotamento linfonodale elettivo (NCCN Guidelines, 2018). Studi randomizzati hanno dimostrato la superiore efficacia in termini di sopravvivenza dello svuotamento linfonodale elettivo in pazienti affetti da carcinomi del cavo orale cN0, quando la profondità d’infiltrazione (DOI) è superiore ai 3 mm. Quando la DOI è compresa tra 2 e 4mm si deve valutare e soppesare quando sia attuabile l’alternativa di un follow-up stringente ed accurato, secondo le specifiche condizioni socio-sanitarie del paziente in esame. In caso di dubbia aderenza al follow-up clinico-strumentale, consigliamo di effettuare uno svuotamento elettivo sovraomoioideo. In conclusione, lo svuotamento selettivo sovra-omoioideo del collo è attualmente indicato nei pazienti con carcinoma squamoso del cavo orale senza evidenza clinica o radiologica di coinvolgimento linfonodale(cN0), da attuarsi in unico tempo con l’asportazione radicale del tumore primario

Microsurgical reconstruction of the mandible in a patient with evans syndrome: a case report and review of the literature

In this report, we describe the first successful case of microvascular free tissue transfer in a patient with Evans Syndrome (ES), a rare form of idiopathic thrombocytopenic purpura (ITP) and associated autoimmune hemolytic anemia (AIHA). Microvascular surgery in the setting of ES is likely to have higher complication rates because of the increased risk of postoperative bleeding and free flap thrombosis. The case presented here opens up to the feasibility of microvascular reconstruction of patients with coagulation disorders like ES. Every effort should be made to control for hemolytic, thrombocytopenic, and thrombophilic states associated with ES. In the absence of evidence-based treatment guidelines for ES, personalized treatment protocols with high-dose corticosteroids, immunoglobulin, and postoperative anticoagulation regimen are highly recommended

PRELIMINARY FINDINGS OF A POTENZIATED PIEZOSURGERGICAL DEVICE AT THE RABBIT SKULL

The number of available ultrasonic osteotomes has remarkably increased. In vitro and in vivo studies have revealed differences between conventional osteotomes, such as rotating or sawing devices, and ultrasound-supported osteotomes (Piezosurgery®) regarding the micromorphology and roughness values of osteotomized bone surfaces. Objective: the present study compares the micro-morphologies and roughness values of osteotomized bone surfaces after the application of rotating and sawing devices, Piezosurgery Medical® and Piezosurgery Medical New Generation Powerful Handpiece. Methods: Fresh, standard-sized bony samples were taken from a rabbit skull using the following osteotomes: rotating and sawing devices, Piezosurgery Medical® and a Piezosurgery Medical New Generation Powerful Handpiece. The required duration of time for each osteotomy was recorded. Micromorphologies and roughness values to characterize the bone surfaces following the different osteotomy methods were described. The prepared surfaces were examined via light microscopy, environmental surface electron microscopy (ESEM), transmission electron microscopy (TEM), confocal laser scanning microscopy (CLSM) and atomic force microscopy. The selective cutting of mineralized tissues while preserving adjacent soft tissue (dura mater and nervous tissue) was studied. Bone necrosis of the osteotomy sites and the vitality of the osteocytes near the sectional plane were investigated, as well as the proportion of apoptosis or cell degeneration. Results and Conclusions: The potential positive effects on bone healing and reossification associated with different devices were evaluated and the comparative analysis among the different devices used was performed, in order to determine the best osteotomes to be employed during cranio-facial surgery

Sol-gel derived bioactive glasses with low tendency to crystallize: synthesis, post-sintering bioactivity and possible application for the production of porous scaffolds.

A new sol-gel (SG) method is proposed to produce special bioactive glasses (BG_Ca family) characterized by a low tendency to devitrify. These formulations, derived from 45S5 Bioglass®, are characterized by a high content of CaO (45.6 mol%) and by a partial or complete substitution of sodium oxide with potassium oxide (total amount of alkaline oxides: 4.6 mol%), which increases the crystallization temperature up to 900°C. In this way, it is possible to produce them by SG preserving their amorphous nature, in spite of the calcination at 850°C. The sintering behavior of the obtained SG powders is thoroughly investigated and the properties of the sintered bodies are compared to those of the melt-derived (M) counterparts. Furthermore, the SG glass powders are successfully used to produce scaffolds by means of a modified replication technique based on the combined use of polyurethane sponges and polyethylene particles. Finally, in the view of a potential application for bone tissue engineering, the cytotoxicity of the produced materials is evaluated in vitro