2015 HSC Section 1 Book of Articles

Management of nonsyndromic craniosynostosis Okada and Gosain

FIGURE 5. Computed tomography scan of a 6-month-old male with right lambdoid synostosis.

predictable desired head shape not possible with simple suturectomy. Cranial vault remodeling and frontoorbital advancement remains the standard operative treat- ment for craniosynostosis, today. The benefit of cranial vault remodeling is that the desired contour is achieved without relying on expansion from the growing brain. Thus, it can be employed successfully on older children who have matured past the age of rapid brain expansion. The pi procedure, one method for treating sagittal craniosynostosis, is named after the shape of the bone removed. Sagittal, coronal and lambdoid sutures are removed and parietal bones are outfractured. The frontal bone is then secured more posteriorly, thus restoring a shorter anterior–posterior cranial dimension [21]. There are many described variations of cranial vault remodeling for each fused suture, but the mainstays of treatment are frontoorbital advance- ment for metopic and coronal synostosis and the judicious use of osteotomies such as barrel-stave techniques to normalize the cranial index and vault height. Surgeons perform remodeling procedures between 4 and 13 months of age and stable results have been demonstrated at 1 year postoperatively [16]. Cranial vault remodeling, while efficacious, is limited by its significant morbidity, including blood loss and prolonged time under anesthesia. In the 1990s Jimenez and Barone [22,23] introduced endo- scopic suturectomy for the treatment of sagittal synostosis, an alternative with minimal blood loss and shorter hospital stay. Their approach was early intervention to capitalize on brain growth and expansion of the skull. They combined suturectomy with orthotic helmet therapy, a passive splinting of the growing calvarium introduced by Persing et al. in

the 1980s [24]. Properly designed helmets limit growth in one dimension while allowing room for compensatory expansion in another. In a study comparing extended strip craniecto- mies without orthotic helmets versus traditional cranial vault remodeling for sagittal craniosynosto- sis, Panchal et al. [25] showed no improvement in cranial index for the strip craniectomy group, whether or not they were operated on before 4 months of age. The cranial vault remodeling group demonstrated age-appropriate cranial index values at 1 year postoperatively. These results imply that simple suture release procedures alone are ineffec- tive and must be coupled with helmet therapy [22,25]. Spring-assisted distraction is a more recent development introduced by Lauritzen et al. [26]. In his follow-up study of 100 consecutive cases, omega-shaped springs designed to either expand or compress were applied across suture osteotomies for sagittal, metopic, bicoronal, and multiple suture synostoses [27]. Average time until spring removal was 7 months for the sagittal synostosis group. Complications included spring dislodgement (5%) in his earlier cases and one case of overcorrection for metopic synostosis. Cranial index in the first 20 patients with sagittal synostosis was normalized from a mean of 67 preoperatively to 74 at 6 months postoperatively, with stable results 3 years later. Hypotelorism was also corrected during the spring-mediated expansion for metopic synostosis. The authors felt that this method had comparable results to other methods of correction, justifying the inherent need for repeat surgery to remove the springs. Distraction osteogenesis has an established role in treating secondary midface hypoplasia in patients

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