NIVALDO ALONSO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Cirurgia, Faculdade de Medicina - Docente
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/04 - Laboratório de Microcirurgia, Hospital das Clínicas, Faculdade de Medicina - Líder
7 resultados
Resultados de Busca
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- Cranial Fossa Development in Differing Subtypes of Crouzon Syndrome(2020) LU, Xiaona; FORTE, Antonio Jorge; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Background: Based on an established classification system of Crouzon syndrome subtypes, detailed regional morphology and volume analysis may be useful, to clarify Crouzon cranial structure characteristics, and the interaction between suture fusion and gene regulated overall growth of the calvarium and basicranium. Methods: CT scans of 36 unoperated Crouzon syndrome patients and 56 controls were included and subgrouped as: type I. Bilateral coronal synostosis; type II. Sagittal synostosis; type III. Pansynostosis; type IV. Perpendicular combination synostosis. Results: Type I of Crouzon syndrome patients developed a slightly smaller posterior fossa (22%), and increased superior cranial volume (13%), which is the only subtype that develops a greater superior cranial volume. The effect of competing increased and decreased segmental volume is associated with a 24% enlargement of overall cranial volume (P = 0.321). In class III, the anterior fossa volume was increased by 31% (P = 0.007), while the volume of posterior fossa was decreased by 19% (P < 0.001). These resulted in a 7% (P = 0.046) reduction in the overall intracranial volume. Type II and type IV patients developed a trend toward anterior, middle, and posterior fossae, and entire cranial volume reduction. Conclusions: Pansynostosis is the most often form of associated craniosynostoses of Crouzon syndrome, however bilateral coronal synostosis may not dominate this form of Crouzon syndrome. The anterior, middle and posterior cranial fossae may have simultaneously reduced volume if the midline suture synostosis is involved. Individualized treatment planning for Crouzon syndrome patient, theoretically should include the patient's age and temporal associated maldevelopment suture sequence.
- Classification of Subtypes of Crouzon Syndrome Based on the Type of Vault Suture Synostosis(2020) LU, Xiaona; SAWH-MARTINEZ, Rajendra; FORTE, Antonio Jorge; WU, Robin; CABREJO, Raysa; WILSON, Alexander; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Background: Patients with Crouzon syndrome develop various types of anatomic deformities due to different forms of craniosynostosis, yet they have similar craniofacial characteristics. However, exact homology is not evident. Different pathology then may be best treated by different forms of surgical technique. Therefore, precise classification of Crouzon syndrome, based on individual patterns of cranial suture involvement is needed. Methods: Ninety-five computed tomography (CT) scans (Crouzon, n = 33; control, n = 62) were included in this study. All the CT scans are divided into 4 types based on premature closure of sutures: class I = coronal and lambdoidal synostosis; class II = sagittal synostosis; class III = pansynostosis; and class IV = ""Others."" The CT scan anatomy was measured by Materialise software. Results: The class III, pansynostosis, is the most prevalent (63.6%). The classes I, III, and IV of Crouzon have significantly shortened entire anteroposterior cranial base length, with the shortest base length in class III. The external cranial measurements in class I show primarily a decreased posterior facial skeleton, while the class III presented with holistic facial skeleton reduction. Class II has the least severe craniofacial malformations, while class III had the most severe. Conclusion: The morphology of patients with Crouzon syndrome is not identical in both cranial base and facial characteristics, especially when they associated with different subtypes of cranial suture synostosis. The classification of Crouzon syndrome proposed in this study, summarizes the differences among each subgroup of craniosynostosis suture involvement, which, theoretically, may ultimately influence both the timing and type of surgical intervention.
- Normal angulation of skull base in Apert syndrome(2018) LU, Xiaona; FORTE, Antonio Jorge; SAWH-MARTINEZ, Rajendra; WU, Robin; CABREJO, Raysa; STEINBACHER, Derek M.; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.Apert syndrome is characterized by the severe craniofacial deformities. The subsequent process of skeletal maldevelopment is likely to be influenced by multiple interactions at several levels, at a given time. In this study, we aimed to explore the evolution of cranial basal dysmorphology and the chronology of these deformities in Apert syndrome, by objectively analyzing three-dimensional measurements. Fifty-four CT scans from unoperated patients (Apert, n = 18; control, n = 36) were included in this study, with age range from 3 days to 24 years. Before 6 months of age, Apert's anterior cranial base was widened 60%. Between 6 months and 2 years of age, the whole cranial base length, anterior cranial base length and posterior cranial base length decreased 8%, 8% and 14%, respectively. The greater sphenoid wing angle was wider by 26.0 degrees, and continued into adulthood. The cranial base angles did not produce significant changes throughout life. The extra cranial distances synchronously and almost proportionally shortened after later infancy. The anterior and posterior cranial base length shortened at an almost proportional rate. The malformations of the skull vault are additive effects with cranial base fusion on skull length restriction, but the angulation of the skull base is virtually normal.
- Morphological Basis for Airway Surgical Intervention in Apert Syndrome(2021) LU, Xiaona; FORTE, Antonio Jorge; PARK, Kitae Eric; ALLAM, Omar; ALPEROVICH, Michael; STEINBACHER, Derek M.; TONELLO, Cristiano; ALONSO, Nivaldo; PERSING, John A.Objective Previous studies have explored the restricted nasopharyngeal airway in Apert syndrome patients. This study aims to investigate the segmented airway volume changes with age and directly analyze their correlations with subcranial dimensions and angulations. Methods Ninety-seven preoperative computed tomography scans (Apert, n = 44; control, n = 53) were included in this study, and divided into 5 age-related subgroups. Computed tomography scans were measured using Mimics and 3-matics software. Results Before 6 months of age, the nasal cavity in Apert syndrome is reduced by 47% (P = 0.002), which gradually approximates normal thereafter; however, there remained a 30% reduction, compared with controls. It is highly correlated with the anteroposterior length of subcranial space, and the position of maxilla and palate. The pharyngeal airway volume in Apert syndrome patients, younger than 6 months, was larger than normal by 129% (P = 0.013). However, between 2 and 6 years of age, the pharyngeal airway becomes smaller than normal, with a 57% (P = 0.010) reduction in childhood and 52% (P = 0.005) in adolescence. It is closely correlated with the intercondylar and intergonial widths. Conclusions Airway compromise in Apert syndrome patients is attributable more to the nasal cavity in infants, but in the older child, it is the pharyngeal region. The restricted nasal airway in Apert syndrome is correlated with the subcranial space length and width, but independent of cranial base flexion. The pharyngeal airway volume in Apert syndrome is not as highly correlated with craniofacial morphology. Rather, it is impacted by the growth of mandible, which often requires surgical intervention later in childhood.
- Orbitofacial morphology changes with different suture synostoses in Crouzon syndrome(2022) LU, Xiaona; FORTE, Antonio Jorge; JUNN, Alexandra; DINIS, Jacob; ALPEROVICH, Michael; ALONSO, Nivaldo; PERSING, John A.This study aims to investigate the influence of different cranial vault suture synostoses on orbital and periorbital morphological development in Crouzon syndrome. Computed tomography (CT) scans of Crouzon syndrome patients who had not undergone operation were subgrouped as follows: type I: bicoronal synostosis; type II: sagittal synostosis; type III: pansynostosis; type IV: perpendicular combinations of suture synostoses; and type V: bilateral squamosal synostosis. CT scans were measured using Materialise software. CT scans of 80 Crouzon syndrome patients and 72 normal controls were included. Orbital bony cavity volume was reduced in all subgroups (16-24%), including type V bilateral squamosal synostosis (16%, p = 0.003), although the reduction in type II sagittal synostosis Crouzon patients failed to reach statistical significance (p = 0.071). Globe volume was reduced only in type I bicoronal synostosis (9%, p = 0.018), while the retrobulbar soft tissue volume decreased in type III pansynostosis group by 11% (p = 0.005). Globe volume projection beyond the orbital rim was increased in all groups (p < 0.001), with the greatest increase in type IV perpendicular combination of sutures synostoses, by 100% (p < 0.001). The anteroposterior length of maxilla was significantly shortened in type I (10%, p = 0.028) and type III (9%, p = 0.022) but developed normally in other groups, although the maxilla was posteriorly displaced in all groups (all p <= 0.026). The influence of squamosal synostosis on craniofacial malformation is not equivalent to that of a major vault suture. Therefore, subtype suture fusion individualized surgical interventions, after initial occipital expansion, likely provide additional benefits in mitigating oculo-orbital disproportion.
- Cephalocranial Disproportionate Fossa Volume and Normal Skull Base Angle in Pfeiffer Syndrome(2021) LU, Xiaona; FORTE, Antonio Jorge; ALLAM, Omar; PARK, Kitae Eric; ALPEROVICH, Michael; STEINBACHER, Derek M.; TONELLO, Cristiano; ALONSO, Nivaldo; PERSING, John A.Background: Pfeiffer syndrome is a rare syndromic craniosynostosis disorder, with a wide range of clinical manifestations. This study aims to investigate the structural abnormalities of cranial fossa and skull base development in Pfeiffer patients, to provide an anatomic basis for surgical interventions. Method: Thirty preoperative CT scans of Pfeiffer syndrome patients were compared to 35 normal controls. Subgroup comparisons, related to differing suture synostosis, were performed. Results: Overall, the volume of anterior and middle cranial fossae in Pfeiffer patients were increased by 31% (P < 0.001) and 19% (P = 0.004), versus controls. Volume of the posterior fossa in Pfeiffer patients was reduced by 14% (P = 0.026). When only associated with bicoronal synostosis, Pfeiffer syndrome patients developed enlarged anterior (68%, P = 0.001) and middle (40%, P = 0.031) fossae. However, sagittal synostosis cases only developed an enlarged anterior fossa (47%, P < 0.001). The patients with solely bilateral squamosal synostosis, developed simultaneous reduced anterior, middle and posterior cranial fossae volume (all P <= 0.002). The overall skull base angulation, measured on both intracranial and subcranial surfaces, grew normally. Conclusion: Enlarged anterior cranial fossae in Pfeiffer syndrome children is evident, except for the squamosal synostosis cases which developed reduced volume in all fossae. Volume of the middle cranial fossa is influenced by associated cranial vault suture synostosis, specifically, sagittal synostosis cases develop normal middle fossa volume, while the bicoronal cases develop increased middle fossa volume. Posterior cranial fossa development is restricted by shortened posterior cranial base length. Surgical intervention in Pfeiffer syndrome patients optimally should be indexed to different suture synostosis.
- Analysis of Airway and Midface in Crouzon Syndromes(2019) FORTE, Antonio J.; LU, Xiaona; HASHIM, Peter W.; STEINBACHER, Derek M.; ALPEROVICH, Michael; PERSING, John A.; ALONSO, NivaldoBackground: Crouzon syndrome is associated with severe respiratory impairment of the upper airway due in part to midfacial dysmorphology. We calculated the distinctive nasal diameter and pharyngeal airway volume in patients with Crouzon syndrome and compared them with age-matched control subjects. Methods: Children with computed tomography scans in the absence of surgical intervention were included. Computed tomography scans were digitized and manipulated using Surgicase CMF (Materialise). Craniometric data relating to the midface and airway were collected. For all linear measurements, mean percent increases or decreases were calculated relative to the size of control subjects, and volumetric assessment of the airway was tabulated. Statistical analysis was performed using t test. Results: Twenty-six computed tomography scans were included (control n = 17, Crouzon n = 9). All children were in early mixed dentition. Pharyngeal airway volume was decreased in patients with Crouzon syndrome relative to control subjects by 46% (P = 0.003). The distance from the posterior tongue to the posterior pharyngeal wall decreased 31% when comparing the Crouzon group versus the control (P = 0.04). Conclusions: Three-dimensional analysis revealed notably decreased pharyngeal and nasal airway volumes in patients with Crouzon syndrome, but nasal bone tissue and soft tissue measurements showed very little change between patients and control subjects.