Anterior synostotic plagiocephaly: a quantitative analysis of craniofacial features using computed tomography.

Masters Degree. University of KwaZulu-Natal, Durban.Anterior synostotic plagiocephaly (ASP) is caused by the premature fusion of one coronal suture, which results in severe craniofacial asymmetry that can be challenging to correct. The various methods of the surgical procedures, as well as the distinctive facial characteristics of ASP, have been well documented. However, there is a paucity of literature pertaining to the quantitative analysis of the craniofacial features that are affected in ASP. This study used preoperative computed tomography (CT) scans to document and compare the morphometry of the anterior cranial fossa (ACF), orbit, and ear on the ipsilateral (synostotic) and contralateral (non-synostotic) sides in a select South African population of patients diagnosed with ASP. The dimensions of the ACF, orbit and the position of the ear on the ipsilateral and contralateral sides were measured using a set of anatomical landmarks on two-dimensional (2D) CT scans of 18 consecutive patients diagnosed with non-syndromic ASP. The differences between the ipsilateral and contralateral sides were computed and expressed as a percentage of the contralateral side. The findings of this study revealed that there was side-to-side asymmetry in the ACF, orbit, and ear. All ACF parameters decreased significantly (t-test; p<0.001) on the ipsilateral side when compared to the contralateral side, resulting in the volume of the ACF being the most affected (-27.7%). In terms of the orbit, on the ipsilateral side, the length-infraorbital rim (IOR), height, and surface area parameters increased significantly (t-test; p<0.001), with the height being the most affected (24.6%). The remaining orbital parameters (length-supraorbital rim (SOR), breadth and volume) decreased significantly (t-test; p<0.001), with the length-SOR parameter being the most affected (-10.8%). Furthermore, the ipsilateral SOR was noted to be displaced more cranially by an average of 3.89mm from the contralateral SOR. With regards to the position of the ipsilateral ear, it was found to be displaced anteriorly (9.33mm) and caudally (5.87mm) from the contralateral ear. This study augments the existing literature by providing actual values to corroborate the hallmark characteristics of ASP. These measures may help surgeons plan the technique and extent of surgical correction of the affected craniofacial structures during corrective surgery as it will provide them with an indication of the extent of the deformity on the ipsilateral side as compared to the contralateral side. The results of this study have the potential to propose a grading system in ASP patients according to severity of the condition if the sample size is increased

What volume increase is needed for the management of raised intracranial pressure in children with craniosynostosis?

Craniosynostosis describes a fusion of one or more sutures in the skull. It can occur in isolation or as part of a syndrome. In either setting, it is a condition which may lead to raised intracranial pressure. The exact cause of raised intracranial pressure in craniosynostosis is unknown. It may be due to; a volume mismatch between the intracranial contents and their containing cavity, venous hypertension, hydrocephalus or airway obstruction, which is often a sequela of an associated syndrome. At Great Ormond Street Hospital, after hydrocephalus and airway obstruction have been treated, the next surgical treatment of choice is cranial vault expansion. This expansion has been shown to reduce intracranial pressure, interestingly despite its success, the reasons behind its benefits are not fully understood. Using reconstructed 3-dimensional imaging, accurate measurement of cranial volumes can now be achieved. The aim of this project is to use the advances in 3-dimensional imaging and image processing to provide novel information on the volume changes that occur following cranial vault expansion. This information will be combined with clinical metrics to create a greater understanding of the causes of raised intracranial pressure in craniosynostosis, why cranial vault expansion treats them and whether there is an optimal volume expansion

Optimization of craniosynostosis surgery: virtual planning, intraoperative 3D photography and surgical navigation

Mención Internacional en el título de doctorCraniosynostosis is a congenital defect defined as the premature fusion of one or more cranial sutures. This fusion leads to growth restriction and deformation of the cranium, caused by compensatory expansion parallel to the fused sutures. Surgical correction is the preferred treatment in most cases to excise the fused sutures and to normalize cranial shape. Although multiple technological advancements have arisen in the surgical management of craniosynostosis, interventional planning and surgical correction are still highly dependent on the subjective assessment and artistic judgment of craniofacial surgeons. Therefore, there is a high variability in individual surgeon performance and, thus, in the surgical outcomes. The main objective of this thesis was to explore different approaches to improve the surgical management of craniosynostosis by reducing subjectivity in all stages of the process, from the preoperative virtual planning phase to the intraoperative performance. First, we developed a novel framework for automatic planning of craniosynostosis surgery that enables: calculating a patient-specific normative reference shape to target, estimating optimal bone fragments for remodeling, and computing the most appropriate configuration of fragments in order to achieve the desired target cranial shape. Our results showed that automatic plans were accurate and achieved adequate overcorrection with respect to normative morphology. Surgeons’ feedback indicated that the integration of this technology could increase the accuracy and reduce the duration of the preoperative planning phase. Second, we validated the use of hand-held 3D photography for intraoperative evaluation of the surgical outcome. The accuracy of this technology for 3D modeling and morphology quantification was evaluated using computed tomography imaging as gold-standard. Our results demonstrated that 3D photography could be used to perform accurate 3D reconstructions of the anatomy during surgical interventions and to measure morphological metrics to provide feedback to the surgical team. This technology presents a valuable alternative to computed tomography imaging and can be easily integrated into the current surgical workflow to assist during the intervention. Also, we developed an intraoperative navigation system to provide real-time guidance during craniosynostosis surgeries. This system, based on optical tracking, enables to record the positions of remodeled bone fragments and compare them with the target virtual surgical plan. Our navigation system is based on patient-specific surgical guides, which fit into the patient’s anatomy, to perform patient-to-image registration. In addition, our workflow does not rely on patient’s head immobilization or invasive attachment of dynamic reference frames. After testing our system in five craniosynostosis surgeries, our results demonstrated a high navigation accuracy and optimal surgical outcomes in all cases. Furthermore, the use of navigation did not substantially increase the operative time. Finally, we investigated the use of augmented reality technology as an alternative to navigation for surgical guidance in craniosynostosis surgery. We developed an augmented reality application to visualize the virtual surgical plan overlaid on the surgical field, indicating the predefined osteotomy locations and target bone fragment positions. Our results demonstrated that augmented reality provides sub-millimetric accuracy when guiding both osteotomy and remodeling phases during open cranial vault remodeling. Surgeons’ feedback indicated that this technology could be integrated into the current surgical workflow for the treatment of craniosynostosis. To conclude, in this thesis we evaluated multiple technological advancements to improve the surgical management of craniosynostosis. The integration of these developments into the surgical workflow of craniosynostosis will positively impact the surgical outcomes, increase the efficiency of surgical interventions, and reduce the variability between surgeons and institutions.Programa de Doctorado en Ciencia y Tecnología Biomédica por la Universidad Carlos III de MadridPresidente: Norberto Antonio Malpica González.- Secretario: María Arrate Muñoz Barrutia.- Vocal: Tamas Ung

New Technologies to Improve Surgical Outcome during Open-Cranial Vault Remodeling

Current approaches for the surgical correction of craniosynostosis are highly dependent on surgeon experience. Therefore, outcomes are often inadequate, causing suboptimal esthetic results. Novel methods for cranial shape analysis based on statistical shape models enable accurate and objective diagnosis from preoperative 3D photographs or computed tomography scans. Moreover, advanced algorithms are now available to calculate a reference cranial shape for each patient from a multi-atlas of healthy cases, and to determine the most optimal approach to restore normal calvarial shape. During surgery, multiple technologies are available to ensure accurate translation of the preoperative virtual plan into the operating room. Patient-specific cutting guides and templates can be designed and manufactured to assist during osteotomy and remodeling. Then, intraoperative navigation and augmented reality visualization can provide real-time guidance during the placement and fixation of the remodeled bone. Finally, 3D photography enables intraoperative surgical outcome evaluation and postoperative patient follow-up. This chapter summarizes recent literature on all these technologies, showing how their integration into the surgical workflow could increase reproducibility and reduce inter-surgeon variability in open cranial vault remodeling procedures

Guideline for Care of Patients with the Diagnoses of Craniosynostosis: Working Group on Craniosynostosis

This guideline for care of children with craniosynostosis was developed by a national working group with representatives of 11 matrix societies of specialties and the national patients' society. All medical aspects of care for nonsyndromic and syndromic craniosynostosis are included, as well as the social and psychologic impact for the patient and their parents. Managerial aspects are incorporated as well, such as organizing a timely referral to the craniofacial center, requirements for a dedicated craniofacial center, and centralization of this specialized care. The conclusions and recommendations within this document are founded on the available literature, with a grading of the level of evidence, thereby highlighting the areas of care that are in need of high-quality research. The development of this guideline was made possible by an educational grant of the Dutch Order of Medical Specialists. The development of this guideline was supported by an educational grant of the Dutch Order of Medical Specialists