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  • Exuberant Growth at the Anterior Fontanel Following Sagittal Synostosis Surgery

    Final Number:

    Ruth E. Bristol MD; Davinder Singh MD; Kelly B. Mahaney MD, MS; Stephen Beals MD

    Study Design:

    Subject Category:

    Meeting: Congress of Neurological Surgeons 2015 Annual Meeting

    Introduction: Craniosynostosis of the sagittal suture can be treated with either open calvarial vault procedures, or with an endoscopic/minimally invasive procedure. When the less invasive procedure is performed, there are two methods for accessing the epidural space: dissection of the anterior fontanel, or burr hole craniostomy.

    Methods: An IRB-approved retrospective review of patients who underwent minimally invasive sagittal synostosis surgery between 2009 and 2012 revealed 179 patients. The surgical team had employed the anterior fontanel approach from April 2009 to May 2011. The same surgeons switched to a burr hole approach in May 2011. Clinic notes and photographs were reviewed to assess for the development of the “volcano sign” in which boney overgrowth is noted at the site of the anterior fontanel.

    Results: In 6 patients, the fontanel was dissected (AF group);, 11 underwent burr holes (BH group) to access the epidural space. Mean follow up was 27 months for the AF group and 19 months for BH group. Four of the 6 AF patients (67%) developed the 747 hump in comparison to 2 of the BH group (18%) (p=0.109) this was significant to p=0.017 with a z-score of 2.213. Cephalic index at last follow up was not significantly different (77.8% vs. 75.3%, p=0.360). There was no significant difference in occipital-frontal circumference percentile (72% vs. 83%, p=0.947). Although no invasive pressure monitoring was carried out, there were no other signs of increased intracranial pressure.

    Conclusions: It appears that the method used initially by this team to dissect the anterior fontanel trended towardresulted in a higher incidence of excessive boney growth at the site of the anterior fontanel. This result trended toward but did not reach statistical significance in our small sample. As a result of this observation, theour team now routinely uses the burr hole approach to access the epidural space. Although this finding has been correlated with increased intracranial pressure in other reports, we do not see signs of that in this cohort. This finding implies a role for dural signaling in the development of bone at suture sites.

    Patient Care: Results of this study may influence technical decision making for people performing this surgery.

    Learning Objectives: Understand options for treatment of sagittal synotosis. Discuss potential implications of dural manipulation.


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