Morphology and outcomes in combined sagittal and unilateral coronal synostosis.

Objective: Combined sagittal and unilateral coronal synostosis is an uncommon multisuture synostosis. The objective of this study was to describe patient demographics, characterize craniofacial morphology, and report surgical outcomes for patients with combined sagittal and unilateral coronal synostosis undergoing surgical repair.

Methods: This was a retrospective cohort study performed as a joint effort between two US pediatric tertiary care institutions. Between 2003 and 2021, 10 patients with combined sagittal and unilateral coronal synostosis who underwent surgical repair were identified. Open repair involved fronto-orbital advancement and calvarial remodeling. Endoscopic repair involved endoscopy-assisted strip craniectomy of fused sutures with subsequent helmet therapy until 12 months of age. Craniofacial morphology was characterized from CT scans with parameters including the cephalic index (CI), orbital index (OI) asymmetry, nasal tip deviation, chin deviation, and anterior cranial fossa area ratio (ACFR). All patients had preoperative CT scans, and postoperative CT scans were analyzed when performed. Demographics, operative details, and complications were obtained via chart review.

Results: Patients were predominantly male (70%) with fusion of left coronal suture (80%). Four patients (40%) underwent open repair, and 6 patients (60%) underwent endoscopic repair. The median operation length was 87 minutes for endoscopic repair and 226 minutes for open repair. Two endoscopic patients (33%) and 2 open patients (50%) required blood transfusion. Four patients (3 endoscopic, 1 open) underwent secondary operations. Preoperatively (n = 10), patients had a median CI of 0.75, with OI asymmetry (median -35%), nasal tip (median 6.9°) and chin deviation (median 9.5°) contralateral to the involved coronal suture, and cranial base asymmetry (median ACFR 0.63). Postoperatively (n = 6), patients had improved CI (median CI 0.81), OI asymmetry (median -22%), chin deviation (median 5.1°), and cranial base asymmetry (median ACFR 0.75) but slightly worse nasal tip deviation (median 8.5°).

Conclusions: Combined sagittal and unilateral coronal synostosis resembles its isolated component phenotypes. Open and endoscopic repairs are safe. Morphological parameters trended toward improvement postoperatively.