Location and Rate of Maximal Head Shape Change in Infants with Sagittal Craniosynostosis Treated with Limited Incision Strip Craniectomy, Barrel Staving and Helmet Therapy: A 2D and 3D Quantitative Analysis

Objective

Sagittal strip craniectomy,is widely used for the treatment of sagittal craniosynostosis to normalize head shape, yet few 3D studies have investigated the rate and location of shape change following surgery. The aim of this study was to determine the velocity and location of the major shape changes after limited incision sagittal strip craniectomy with barrel staving and postop helmet therapy.  

Methods

After IRB approval, a retrospective chart review of all patients treated with strip craniectomy and barrel stave’s at our institution was undertaken. Selection criteria included: 1) diagnosis of sagittal craniosynostosis; 2) treatment age less than 200 days; 3) compliance with and completion of helmet therapy through 1 year of age.  Results of cranial index (CI), maximal anterior-posterior length and maximal width were obtained from preoperative 3D surface scans to the end of helmet therapy. To determine the stabilization of CI, longitudinal CI measurements were obtained during helmet therapy.  Then the measurements were fitted using an exponential equation and the end point of CI was estimated when the curve stabilizes at a change less than 0.01 CI/day. Postoperative results were classified as excellent (CI > 80), good (CI 70-80) and poor (CI < 70)¹. In addition,  the change in head shape from preoperative to postoperative was evaluated using 3D analysis.

Results

20 patients met selection criteria (6 Female, 14 male).   The average age of surgery was 109.2±19.7 days (range 83-146). There was a significant increase in the CI from 71.7±3.8 (range 63-77.9.) preoperative to 81.1±4.2 (range 73-89.8) postoperative. 60% of patients had an excellent result and 40% had a good result. The average duration of postoperative helmet therapy was 334±97.8 days (range 132-514.). The average postoperative time until stabilization of cranial index was 52.4± 24.7 days. 3D analysis demonstrated the posterior third to have the most change in shape, and this was both in skull height and anterior-posterior dimension. No postoperative complications occurred. 

Conclusions

Limited incision sagittal strip craniectomy with barrel staving and postop helmet therapy produces a rapid change in CI and head shape. This suggests that the duration of helmet therapy may be shortened which could impact cost and burden of care.  Further studies are needed to determine the effects of varied duration of postoperative helmet orthotic therapy and head shape.