Are endoscopic and open treatments of metopic synostosis equivalent in treating trigonocephaly and hypotelorism?

Background: Patients with metopic craniosynostosis are traditionally treated with fronto-orbital advancement to correct hypotelorism and trigonocephaly. Alternatively, endoscopic-assisted treatment comprises narrow ostectomy of the fused suture followed by postoperative helmet therapy. Here we compare the preoperative and 1-year postoperative results in open versus endoscopic repairs.
Methods: We reviewed preoperative and 1-year postoperative three-dimensional reconstructed computed tomography scans of patients treated for nonsyndromic metopic craniosynostosis by either open (n = 15) or endoscopic (n = 13) technique. Hypotelorism was assessed by interzygomaticofrontal distance and intercanthal distance. Trigonocephaly was assessed by 2 independent angles: first, an axial-plane two-dimensional angle between zygomaticofrontal suture bilaterally and the glabella (ZF(R)-G-ZF(L)); second, an interfrontal angle (IFA) between the most anterior point from a reconstructed midsagittal plane and supraorbital notch bilaterally. Age-matched scans of unaffected patients (n = 28) served as controls for each postoperative scan.
Results: Patients with open repair (9.5 ± 1.8 months) were older at time of surgery than patients with endoscopic repairs (3.3 ± 0.4 months) (P = 0.004). Male-to-female ratios were equivalent at roughly 7:3 in both groups. Preoperatively, the endoscopic group had worse hypotelorism and ZF(R)-G-ZF(L) than the open group (P ≤ 0.04). After accounting for preoperative differences, all of the postoperative measurements (ie, interzygomaticofrontal distance, intercanthal distance, ZF(R)-G-ZF(L) angle, IFA) of the 2 groups were statistically equivalent (P ≥ 0.135). Trigonocephaly was significantly improved after repair in both the open (8 degrees [ZF(R)-G-ZF(L)] and 18 degrees [IFA]) and endoscopic (13 degrees [ZF(R)-G-ZF(L)] and 16 degrees [IFA]) groups (P < 0.001). Postoperative measures in both groups were equivalent to controls (0.12 < P < 0.89). Intrarater reliability ranged from 0.93 to 0.99 for all measurements.
Conclusion: Our retrospective series shows that endoscopic and open repairs of metopic craniosynostosis are equivalent in improving hypotelorism and trigonocephaly at 1-year follow-up. Additional studies are necessary to better define minor differences in morphology, which may result from the different techniques.