Delayed synostoses of uninvolved sutures after surgical treatment of nonsyndromic craniosynostosis

Background: Craniosynostosis causes significant cranial deformity in the pediatric population. Open and endoscopic-assisted surgeries have led to increasingly successful management of this condition. Following surgical reconstruction, subsequent development of postnatal synostosis of previously patent sutures have been described and noted to be most frequently associated with multisuture synostosis patients with syndromic diagnoses. Very rarely, postsurgical new sutural fusion has been identified in nonsyndromic patients who initially present with isolated single-suture synostosis. The purpose of this study was to evaluate the incidence of new synostosis among patients who had undergone craniosynostosis reconstruction with either the open or endoscopic technique. Methods: Patients undergoing open and endoscopic surgery for nonsyndromic craniosynostosis were reviewed. Preoperative and postoperative imaging and clinical information were reviewed, and cases showing progressive cranial deformity were identified. Results: Three (2.1%) of 145 patients undergoing open craniosynostosis surgery and 2 (1.7%) of 121 patients undergoing endoscopic surgery developed delayed fusion of an additional suture during follow-up. This was identified at a median of 16.4 months after initial surgery in the open group and 15.25 months after surgery in the endoscopic group. In patients undergoing open surgery, each patient developed new sagittal synostosis after initial presentation of coronal synostosis in 1 patient and metopic synostosis in 2 patients. In patients undergoing endoscopic surgery, each patient developed new coronal synostosis after sagittal repair. Conclusions: Management of craniosynostosis has evolved over time with increasing availability of effective and safe treatments. During long-term follow-up, a small number of patients may develop premature closure of a different suture that did not undergo surgical manipulation. In our case, series, we identified 3 patients undergoing open surgery and 2 patients undergoing endoscopic surgery for nonsyndromic, single-suture craniosynostosis. This finding supports the necessity of long-term clinical follow-up and the utility of delayed imaging when clinical suspicion indicates.