Abstract

At birth, a baby’s skull is formed by hard bone parts that are joined by soft tissue called sutures. These sutures play a fundamental role in allowing the baby natural birth and head growth in the first few years. By the time the baby is two, the head has quadrupled in size. Sutures become bone when the child grows older. In babies affected by craniosynostosis (one in 2000 births), one or more of the skull sutures harden prematurely. If this happens, the head develops abnormally and brain growth is restricted, leading to eyesight, hearing and breathing problems and developmental delays.   

Scaphocephaly (“boat-shaped head”) is a type of craniosynostosis that results in babies having long and narrow heads. This is corrected with surgery, where the cranial bones are cut and repositioned into a normal head shape. The operation is extensive and requires a long hospital recovery. Surgeons at Great Ormond Street Hospital (GOSH) have pioneered a new technique, in which just two small cuts are performed on the skull and spring-like-devices are temporarily inserted to widen the skull and normalise the shape. This new operation has proved effective in shortening operative time and ensuring a speedy recovery. The current modelling efforts of the GOSH craniofacial unit research group have produced a numerical model able to predict the skull reshaping up to 4 weeks post-surgery. I will expand this model using known methods of cranial growth to take into account late skull development and predict long term outcomes of the procedure. This will help surgeons plan the surgery and will be used in the future to inform patients and parents about the procedure.   

Research question

Is it possible to predict the long-term outcome of spring cranioplasty using published methods for modelling head growth in paediatric patients?

The GOSH group has created a numerical model able to predict the early surgical outcome of spring cranioplasty by means of medical image processing and numerical modelling. The results have been presented at international conferences and disseminated in peer reviewed international journals. The model is currently validated using data on early reshaping of cranial skulls (0-4 weeks), but it is known that further remodelling of shape (due to the baby’s head growing) occurs after this period, which affects the final outcome of the treatment. The extended model will be used, and then validated on medical imagery from 4 weeks to 3 months after the surgery.  

Objectives

I will first collect data from the clinical database of GOSH of patients who underwent spring cranioplasty and whose parents consented to research. I will then create patient specific models from medical imaging, simulating the surgical procedures using the parameters of surgery (position and model of the spring used). After that, I will simulate early cranial reshaping (0-4 weeks) using the published method. I will test several methods for modelling cranial growth, which have been recently published, in this model to simulate the long-term growth (4 weeks to 3 months) of the paediatric skull following spring insertion. 

Finally, I will validate my model using non-ionising preoperative imaging performed at GOSH and discuss my results with the rest of the clinical team. To make this project feasible in six weeks, I will aim to complete this process for only 2-3 patients.