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Ruth E. Bristol, MD
Craniosynostosis is a congenital defect of skull bone development that results in abnormal head shapes and potential brain growth constriction. The visible physical abnormalities can also lead to psychological and social challenges for affected individuals. It affects 1 out of every 2,000 to 2,500 live births worldwide and is clinically and genetically heterogeneous. Most cases are non-syndromic. Craniosynostosis may, however, be associated with genetic mutations or syndromes, such as Apert syndrome, Crouzon syndrome or Pfeiffer syndrome. Identifying these genetic factors can have implications for management, prognosis, family planning and counseling. Surgical repair is generally recommended, and often carried out in infancy. Early diagnosis is important and allows for timely intervention and optimal outcomes.
Innovations in craniosynostosis management and cranial vault remodeling have improved diagnosis, preoperative planning and treatment in recent years. This, in turn, has improved patient outcomes, reduced the invasiveness of surgical procedures and provided more personalized and comprehensive care for affected children. Some of these innovations have included minimally invasive surgery, cranial distraction, bone thickness analysis and 3D printing.
Springs for Multi-Suture
All specialties in medicine are attempting to introduce “minimally invasive” techniques with the goal of providing safer and faster treatments with quicker recovery and less pain. Craniosynostosis has been an ideal diagnosis for application of this concept. Smaller incisions, with less bone removal, facilitate lower blood loss and faster recovery times. One of the developments in this field has been the use of spring-mediated cranioplasty. The application of metal springs to gently push skull bones in the desired direction has reduced the need for large bone cuts. Surgery is of shorter duration than the traditional open approaches, patients go home sooner, and there is no need for bulky helmets used with other minimally invasive approaches. The springs remain in place for 2–3 months and are then removed in a minor outpatient procedure. The skull also achieves a smoother contour than when multiple bone grafts are reconstructed. While these springs were initially used only for single-suture synostosis, at Phoenix Children's we have begun offering this approach to our multi-suture patients, as well (Figure 1). Since the work of the springs is slower, the tissues stretch farther over time, allowing for greater correction than with open reconstruction. There is hope that this will also reduce the need for secondary surgeries in the future.
Figure 1: Two lateral views of the skull showing the action of the springs over time, to widen the gap between the bones and improve skull shape.
Bone Thickness Analysis
All surgery carries the risk of blood loss. In young infants, this can reach a level requiring transfusion, even when the surgery goes as planned. Our team has previously investigated the impact of a medication to improve clotting (Tranexamic acid) and reported reduced blood loss and transfusion rate with a standard protocol.1 One of the contributors to blood loss in craniosynostosis surgery is the thickness of the patient’s bone. In a recent study, our craniofacial team identified preoperative findings on CT scans that will allow us to predict, more accurately, which patients are at risk for higher blood loss.2 Greater bone thickness in certain areas has also been found to correlate with higher blood loss. This knowledge allows the surgical team to plan bone cuts so as to minimize this impact and be able to counsel families ahead of time about the likelihood of a blood transfusion. Although our patients already enjoy a low rate of blood transfusion, we are hopeful to reduce this further with this new application (Figure2).
3D Printing for Posterior Vault Distraction Osteogenesis (PVDO) Placement
3D printing technology has been a valuable tool in the management of craniosynostosis. It allows patient-specific models of the skull to be created, aiding surgeons in planning procedures, reducing planning time and improving precision during surgery. One of the craniofacial procedures offered at Phoenix Children's requires the placement of distraction devices on skull bones to expand the skull vault to allow more room for brain growth. These devices are small metal plates with an arm in between that can be pushed apart to widen the gap between bones (Figure 3). The decision regarding placement of these devices requires the calculation of force vectors, bone thickness analysis and skin incision alignment. The 3D models allow for much of this planning to be completed ahead of time rather than while the patient is under anesthesia. The 3D model can be manipulated on a computer screen to select the best distractor placement ahead of time. The model can then be sterilized and placed directly on the patient’s skull as a template in real time in the operating room (Figure 4).
Figure 3: Two lateral views of the skull showing before and after distraction. This enlarges patient’s skull volume so they do not develop brain constriction.
Figure 4: A custom, 3D printed guide is generated based on the pre-operative CT scan to provide exact location of the footplates and screw holes for the distractors. This 3D guide is sterilized and opened directly onto the surgical field.
Coordinated, multidisciplinary care is essential to addressing all aspects of craniosynostosis care and providing quality outcomes. The craniofacial team at Phoenix Children’s brings together a group of experienced healthcare professionals from different specialties to collaborate on the diagnosis, personalized treatment plans and ongoing care of our craniosynostosis patients. This approach, coupled with a spirit of innovation, has led to more effective and efficient treatment, which improves patient care and outcomes.
- Kurnik NM, Pflibsen LR, Do A, Bristol R, Singh DJ. Craniosynostosis Surgery and the Impact of Tranexamic Acid Dosing. J Craniofac Surg. 2018 Jan;29(1):96-98.
- Grove AM, Kirsch HM, Kurnik NM, Bristol RE, Sitzman TJ, Pfeifer C, Singh DJ. Preoperative Frontal and Parietal Bone Thickness Assessment to Predict Blood Loss and Transfusion During Extended Suturectomy for Isolated Sagittal Craniosynostosis. Cleft Palate Craniofac J. 2023 Sept; Epub ahead of print. PMID: 37710993.