Partial Suture Fusion in Nonsyndromic Single-Suture Craniosynostosis

Degree of Sagittal Suture Fusion, Cephalic Index, and Head Shape in Nonsyndromic Sagittal Craniosynostosis

BACKGROUND

Sagittal craniosynostosis may present with complete or partial fusion of the sagittal suture, but relationships between degree of sagittal suture fusion and head shape are currently poorly described. The aim of this study was to characterize sagittal suture fusion patterns and determine associations with head shape in a cohort of patients with nonsyndromic sagittal craniosynostosis.

METHODS

Patients with nonsyndromic sagittal craniosynostosis at a tertiary care center with available computed tomography imaging were included in this study. The anterior and posterior distances of sagittal suture patency were measured along 3-dimensional parietal bones. Degree of sagittal suture fusion was compared to head shape characteristics, including cephalic index (CI), frontal bossing, and occipital bulleting.

RESULTS

Ninety patients (69 male) were included in this retrospective study. The sagittal suture was on average 85.6±20.1% fused, and 45 (50.0%) patients demonstrated complete fusion of the sagittal suture. CI was associated with increased degree of fusion for the anterior one-half (ρ=0.26, P=0.033) and anterior one-third (ρ=0.30, P=0.012) of the sagittal suture. Complete fusion of the anterior one-third of the sagittal suture predicted higher CI (β=13.86, SE=6.99, z=-0.25, P=0.047). Total degree of sagittal suture fusion was not predictive of CI or head shape in any analysis.

CONCLUSIONS

Decreased fusion of the anterior one-third of the sagittal suture, but not total suture, may paradoxically predict increased severity of scaphocephaly as quantified by CI in nonsyndromic sagittal craniosynostosis.

Partial suturectomy for phenotypical craniosynostosis caused by incomplete fusion of cranial sutures: a novel surgical solution

OBJECTIVE

Patients presenting with head shape changes phenotypical for craniosynostosis may have incomplete fusion of the involved sutures. The surgical literature is lacking in appropriate management strategies for these patients. In this paper, the authors evaluate their experience with a novel treatment strategy: suturectomy of only the fused portion followed by helmeting therapy in patients with skull deformity secondary to incomplete suture synostosis.

METHODS

Patients with craniosynostosis with incomplete suture fusion requiring operative intervention between 2018 and 2020 were included for evaluation. Patients were selected for partial suturectomy if the patent portion of the suture had a normal appearance. All patients underwent craniectomy of the involved portion of the synostosed suture. Intraoperative ultrasound was used to reassess the degree of fusion at the time of surgery and incision planning. A 2- to 3-cm strip craniectomy was performed under direct visualization through a single minimal access incision. Postoperative helmeting was utilized for all patients. Demographic and perioperative data were collected, including laser scan data in the form of cranial index (CI) and cranial vault asymmetry (CVA), defined as the difference between two diagonal measurements, from the frontozygomaticus to the opposite eurion.

RESULTS

Four males and 1 female with a mean age of 2.8 months (range 1.1-3.9 months) at presentation were included. All patients had incomplete sagittal synostosis (one patient also had an incomplete left lambdoid synostosis and another had an incomplete left coronal synostosis). The mean age at surgery was 3.5 months (range 2.0-4.7 months) without any major complications. All patients were compliant with postoperative helmeting. The average age at the last follow-up was 12.8 months (range 5.3-23.7 months) with a mean follow-up duration of 9.3 months (range 0.5-19.6 months). Final laser scan evaluations were available for 3 patients and showed an improvement of the CI from an average of 71.3 (range 70-73) to 84.3 (range 82-86). The CVA improved from an average of 9.67 mm (range 2-22 mm) to 1.67 mm (range 1-2 mm).

CONCLUSIONS

Minimally invasive direct excision of the involved portion of fused cranial sutures followed by helmet therapy for phenotypical craniosynostosis is a safe and effective treatment strategy. This technique is suitable for very young patients and appears to offer similar outcomes to complete suturectomy. Further studies are required to see if this approach reduces the deformity severity for patients requiring vault remodeling later in life.