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.