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
2 resultados
Resultados de Busca
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- Skull Base Cephalometric Changes in Cranial Expansion by Springs(2011) DORNELLES, Rodrigo de Faria Valle; CARDIM, Vera Lucia Nocchi; PINTO, Ana Carolina Brandao de Campos Fonseca; ALONSO, NivaldoBackground: The use of springs in cranial expansion has demonstrated to be effective for craniosynostosis treatment. The spring-exerted expansile action has been observed when springs are placed both in the sagittal and parasagittal regions, mainly in scaphocephaly. In this study, a variation in cephalometric measurements under expansible spring action on the skull base was analyzed. Methods: Thirteen 4-week-old New Zealand white rabbits were divided into 4 groups: group 1, in which only amalgam markers were used (control); group 2, in which amalgam markers were used, and a sagittal suturectomy was performed; group 3, in which amalgam markers were used, and a sagittal suturectomy was performed with placement of expansible springs in the interparietal region; and group 4, in which markers were used, and a linear parasagittal craniectomy was performed with spring placement. All animals were killed at weeks 2, 4, 8, and 12. Radiologic control with cephalometric study was performed. Results: Distraction of amalgam markers in the groups with springs was greater than in those without springs. A proportional change in the angles measured through craniometry was observed in these groups. Conclusions: The experimental rabbit model was shown to be adequate to the analysis proposed by the study. Under the action of springs, the groups with sagittal and parasagittal osteotomy were found to present a similar distraction of amalgam markers. A concomitant change in cephalometric measurements occurred, suggesting a change in the skull base mediated by expansible springs placed both in the sutural and nonsutural sites.
- 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.