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
6 resultados
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- Anterior convex lateral orbital wall: distinctive morphology in Apert syndrome(2018) LU, X.; FORTE, A. J.; SAWH-MARTINEZ, R.; WU, R.; CABREJO, R.; STEINBACHER, M.; ALPEROVICH, M.; ALONSO, N.; PERSING, J. A.Bony malformations of the orbit and alterations to the soft tissue in Apert syndrome contribute to ophthalmic dysfunction. Recognised structural malformation of the sphenoid and ethmoid sinuses, together with corresponding deformities in the anterior and middle cranial base, are characteristic. Our aim was to explore the underlying structural components of disfigurement and the consequent development of the orbit in patients with Apert syndrome over time by studying 18 preoperative computed tomographic (CT) scans of affected patients and 36 scans from controls. Cephalometric measurements related to the orbit were collected, and analysed with Materialise software. The patients with Apert syndrome had larger than normal external orbital horizontal angles between the ages of 6 months and 2 years. The inside horizontal angle was narrower at 16.36 degrees before 6 months, and continued to decrease into adulthood. The ethmoid and sphenoid side angles in affected patients consistently increased, starting at 7.93% and 14.68% of the external horizontal angle, respectively, during the first 6 months of age, and becoming 20.55% and 11.69%, respectively, in adulthood. In unaffected patients, both angles were less than 3% of the external horizontal angle overall. The orbital vertical angle also changed synchronously, with increasingly wide lateral orbits and shortened anteroposterior orbits. The anterior protrusion of the lateral orbital wall resulted from superior and posterior rotation of a curved, greater wing of the sphenoid, while the widened median orbital wall was caused by the widened ethmoid sinus. These resulted in bony deformities of the orbit, which predisposed to the visual impairments of Apert syndrome.
- Does different cranial suture synostosis influence orbit volume and morphology in Apert syndrome?(2022) LU, X.; FORTE, A. J.; ALPEROVICH, M.; ALONSO, N.; PERSING, J. A.This study was performed to compare the orbital and peri-orbital morphological variations in Apert syndrome patients with different cranial vault suture synostosis, so as to provide an anatomic basis for individualized surgical planning. Computed tomography scans of 57 unoperated Apert syndrome patients and 59 controls were subgrouped as follows: type I, bilateral coronal synostosis; type II, pansynostosis; type III, perpendicular combinations of cranial vault suture synostoses. Orbit bony cavity volume was significantly reduced in type I and type II, by 19% (P < 0.001) and 24% (P < 0.001), respectively. However, the reduction of orbital cavity volume in type III did not reach statistical significance. Globe volume projection beyond the orbital rim, however, increased by 76% (P < 0.001) in type III, versus an increase of 54% (P < 0.001) in type I and 53% (P < 0.001) in type II, due to different ethmoid and sphenoid bone malformations. Maxillary bone volume was only significantly reduced in type I bicoronal synostosis (by 24%, P = 0.048). Both type I and type II developed relatively less zygoma and sphenoid bone volume. Different cranial vault suture synostoses have varied influence on peri-orbital development in Apert syndrome. Instead of mitigating the abnormalities resulting from bicoronal synostosis in type I, additional midline suture synostosis worsens the exorbitism due to a more misshaped ethmoid.
- 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.
- Growth patterns of the airway in Crouzon syndrome patients with different types of cranial vault suture synostosis(2021) LU, X.; FORTE, A. J.; WILSON, A.; PARK, K. E.; ALLAM, O.; ALPEROVICH, M.; STEINBACHER, D. M.; TONELLO, C.; ALONSO, N.; PERSING, J. A.The severity of obstructive respiratory difficulty varies among affected Crouzon syndrome patients. The aim of this study was to investigate the correlation between the restricted airway volume in Crouzon syndrome and the associated type of cranial vault suture synostosis. Computed tomography scans of 68 unoperated Crouzon syndrome patients and 89 control subjects were subgrouped into four types: type I, bilateral coronal synostosis; type II, sagittal synostosis; type III, pansynostosis; type IV, perpendicular combinations of synostoses. Measurements were made using Mimics software. Of type I Crouzon patients, 42% had a restricted nasal airway (P = 0.002), while the pharyngeal airway volume was not significantly reduced. Type II Crouzon patients grew normal segmental airway volumes. Crouzon patients of type III developed simultaneously reduced nasal and pharyngeal airway volumes in infancy, by 38% (P = 0.034) and 51% (P = 0.014), respectively. However, the nasal airway achieved a normal volume by 2 years of age without any intervention, while the pharyngeal airway remained significantly reduced up to 6 years of age, by 42% (P = 0.013), compared to controls. Type IV Crouzon patients developed a reduced nasal airway volume (32%, P = 0.048) and a non-significant restricted pharyngeal airway (18%, P = 0.325). Airway compromise in Crouzon syndrome is variable when associated with different craniosynostosis fusion patterns. Type II (sagittal synostosis) Crouzon patients grew a normal nasopharyngeal airway volume. Those with types I (bicoronal synostosis) and IV (perpendicular synostoses) had significantly restricted nasal airways and a tendency towards a reduced pharyngeal volume. Type III (pansynostosis) Crouzon infants had the worst restriction of both airways, although there was some improvement with age.
- 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.
- 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.