Coronal Suturectomy Does Not Cause Acute Postoperative Displacement in the Cranial Bases of Craniosynostotic Rabbits

Abstract

Approximately 300 to 500 infants per 1,000,000 have prematurely fused cranial sutures (craniosynostosis). Craniosynostosis can result in increased intracranial pressure and craniofacial deformities, which often require extensive and costly craniofacial surgery. Because the neurocranium and basicranium are developmentally interrelated, understanding their influence on one another is important for surgical planning. Although surgery has been found to have long-term effects on the cranial bases of craniosynostotic human beings and rabbits, the biological mechanisms behind these effects remain uncertain. Some researchers have suggested that the surgical release of synostosed sutures alters long-term growth patterns, resulting in cranial base differences between craniosynostotic individuals who undergo surgery and those who do not. Additionally, some investigators have proposed that an acute and surgically related displacement of basicranial elements may contribute to the observed differences. The current study examines acute postoperative changes in four lengths, three angles, and three triangles between cranial base landmarks in a sample of seven New Zealand white rabbits with familial nonsyndromic craniosynostosis. Results indicate that suturectomy caused no statistically significant (P < 0.05) acute length, angular, or shape differences in the cranial base. Thus, previous long-term cranial base differences found between rabbits that were operated on and those that were not were probably not caused by an acute displacement of skeletal elements as a result of surgery. These findings suggest that postoperative cranial base changes may be related more to chronically altered growth patterns than to acutely altered changes in intracranial pressure or dural tension.

Intrauterine Fetal Constraint Induces Chondrocyte Apoptosis and Premature Ossification of the Cranial Base

“…These studies use a system of standardized measurements, such as angles and distances created by basicranial landmarks, or computer software capable of comparing three-dimensional coordinates mapped in space. 8,10,11,14,32,37,38 While the findings of such investigations are useful in elucidating the temporal sequence and magnitude of macroscopic changes in the cranial base and vault that accompany sutural synostosis, they tell us little about the actual mechanisms through which malformations in one portion of the craniofacial skeleton result in deformations in distant sites.…”

Techniques of Experimentation

“…25.21) (Chaplin et al, 1999). Rabbits have been used to investigate craniosynostosis which can be associated with calvarial and midfacial abnormalities and leads to optic nerve compression, blindness, and mental retardation (Putz et al, 2002;Fellows-Mayle et al, 2006). Images courtesy of Dr. Michael Talcott, 2011;www.jedpwebermd.com. LABORATORY ANIMAL MEDICINE Renella and Hussein (1986) have described a microsurgical approach to the cerebellomedullary region of the rat, which provides access to the medulla and basal cerebellum.…”

Molecular Analysis of Gli3, Ihh, Rab23, and Jag1 in a Rabbit Model of Craniosynostosis

“…Pedigree analysis suggests that this condition is inherited in an autosomal dominant fashion with variable expression (Mooney et al, 1996). We have utilized the rabbit colony to model therapies for both postoperative reossification (Putz et al, 2002a, 2002b; Cooper et al, 2007; Mooney et al, 2007a, 2007b; Frazier et al, 2008; Gilbert et al, 2016) and the prevention of initial suture fusion (Losken et al, 1998, 1999; Chong et al, 2003; Cray et al, 2010, 2012). Results from these studies demonstrate that this colony is producing craniosynostotic, but otherwise normal, healthy rabbits and show that the pathological findings from this rabbit model are strikingly similar to clinical findings noted in human infants with primary, familial craniosynostosis (Cohen, 1993; Mooney et al, 1994a, 1996; Wilkie and Wall, 1996; Cohen and MacLean, 2000).…”