Parasagittal suture after strip craniectomy

Coronal and lambdoid suture evolution following total vault remodeling for scaphocephaly

OBJECTIVE

Different types of surgical procedures are utilized to treat craniosynostosis. In most procedures, the fused suture is removed. There are only a few reports on the evolution of sutures after surgical correction of craniosynostosis. To date, no published study describes neosuture formation after total cranial vault remodeling. The objective of this study was to understand the evolution of the cranial bones in the area of coronal and lambdoid sutures that were removed for complete vault remodeling in patients with sagittal craniosynostosis. In particular, the investigation aimed to confirm the possibility of neosuture formation.

METHODS

CT images of the skulls of children who underwent operations for scaphocephaly at the Hôpital Femme Mère Enfant, Lyon University Hospital, Lyon, France, from 2004 to 2014 were retrospectively reviewed. Inclusion criteria were diagnosis of isolated sagittal synostosis, age between 4 and 18 months at surgery, and availability of reliable postoperative CT images obtained at a minimum of 1 year after surgical correction. Twenty-six boys and 11 girls were included, with a mean age at surgery of 231.6 days (range 126-449 days). The mean interval between total vault reconstruction and CT scanning was 5.3 years (range 1.1-12.2 years).

RESULTS

Despite the removal of both the coronal and lambdoid sutures, neosutures were detected on the 3D reconstructions. All combinations of neosuture formation were seen: visible lambdoid and coronal neosutures (n = 20); visible lambdoid neosutures with frontoparietal bony fusion (n = 12); frontoparietal and parietooccipital bony fusion (n = 3); and visible coronal neosutures with parietooccipital bony fusion (n = 2).

CONCLUSIONS

This is the first study to report the postoperative skull response after the removal of normal patent sutures following total vault remodeling in patients with isolated sagittal synostosis. The reappearance of a neosuture is rather common, but its incidence depends on the type of suture. The outcome of the suture differs with the incidence of neosuture formation between these transverse sutures. This might imply genetic and functional differences among cranial sutures, which still have to be elucidated.

Neosagittal Suture Formation after Endoscopic Sagittal Strip Craniectomy: A Case Report and Literature Review

The fate of the excised synostotic suture in craniosynostosis remains relatively understudied. The purpose of this report is to describe a case of neosagittal suture formation following endoscopic excision of a pathology-proven synostotic suture, with CT demonstration of complete reossification in the areas adjacent to the neosagittal suture. We additionally review the existing literature on neosuture formation that has been published over the past 50 years. We conclude that continued investigation is warranted, both through histological comparison of normal and neosutures and through studies to determine clinical risk factors, as this may improve our understanding of the underlying mechanism of pathologic premature suture fusion in craniosynostosis.

Neo-Sagittal Suture Formation After Cranial Vault Remodeling in Sagittal Craniosynostosis

ABSTRACT

Craniosynostosis is a condition where the cranial sutures are early fused. Sagittal suture synostosis is found to be the most prevalent. Many techniques ranging from simple suture excision to wide suturectomy have been developed for treating this condition. While repeated fusion of previously excised involved sutures is common, neosuture formation has been identified in many recent reports after craniosynostosis surgery. In this case report, the authors present a finding of the neosuture formation in a patient presented with sagittal craniosynostosis after wide suturectomy with total cranial vault remodeling so that the pathologically fused suture can be reversed.

Craniosynostosis: A Reversible Pathology?

The formation of the cranial sutures, in utero, occurs when the ossification of the skull bones reaches predestined positions around gestational week 15 to 20. Craniosynostosis, and the consequent skull shape deformities, is treated with surgery including osteotomies of the fused sutures. The occasional appearance of a new suture in the osteotomy lines has previously been described as sporadic events. In this retrospective study, a 4-year consecutive series of osteotomies combined with springs for craniosynostosis were systematically analysed regarding the appearance of neosutures. In total, 84 patients were included and in 16 patients (19%) a new radiologically normal suture appeared in a part of the suture that was completely closed preoperatively. Additionally, in 7 patients (8%) a new suture appeared in a part of the suture that had a discernible suture prior to surgery.In conclusion, in this consecutive and well-defined patient cohort operated for craniosynostosis, the formation of a neosuture is not a rare, and speculatively not a random, event. The appearance of a new suture long after the normal time period for suture formation in utero indicates that the craniosynostosis may just as well be caused by disturbed formation of the suture as actual premature closure.

Neosuture formation after endoscope-assisted craniosynostosis repair

OBJECTIVE The goal of this study was to identify the rate of neosuture formation in patients with craniosynostosis treated with endoscope-assisted strip craniectomy and investigate whether neosuture formation in sagittal craniosynostosis has an effect on postoperative calvarial shape. METHODS The authors retrospectively reviewed 166 cases of nonsyndromic craniosynostosis that underwent endoscope-assisted repair between 2006 and 2014. Preoperative and 1-year postoperative head CT scans were evaluated, and the rate of neosuture formation was calculated. Three-dimensional reconstructions of the CT data were used to measure cephalic index (CI) (ratio of head width and length) of patients with sagittal synostosis. Regression analysis was used to calculate significant differences between patients with and without neosuture accounting for age at surgery and preoperative CI. RESULTS Review of 96 patients revealed that some degree of neosuture development occurred in 23 patients (23.9%): 16 sagittal, 2 bilateral coronal, 4 unilateral coronal, and 1 lambdoid synostosis. Complete neosuture formation was seen in 14 of those 23 patients (9 of 16 sagittal, 1 of 2 bilateral coronal, 3 of 4 unilateral coronal, and 1 of 1 lambdoid). Mean pre- and postoperative CI in the complete sagittal neosuture group was 67.4% and 75.5%, respectively, and in the non-neosuture group was 69.8% and 74.4%, respectively. There was no statistically significant difference in the CI between the neosuture and fused suture groups preoperatively or 17 months postoperatively in patients with sagittal synostosis. CONCLUSIONS Neosuture development can occur after endoscope-assisted strip craniectomy and molding helmet therapy for patients with craniosynostosis. Although the authors did not detect a significant difference in calvarial shape postoperatively in the group with sagittal synostosis, the relevance of neosuture formation remains to be determined. Further studies are required to discover long-term outcomes comparing patients with and without neosuture formation.

Operative Management of Nonsyndromic Sagittal Synostosis: A Head-to-Head Meta-analysis of Outcomes Comparing 3 Techniques

BACKGROUND

The timing and surgical technique for the treatment of sagittal synostosis remain controversial. Calvarial vault remodeling (CVR), strip craniectomy (SC), and spring-mediated cranioplasty (SMC) are currently in use. We perform a meta-analysis of the literature to compare these 3 techniques.

METHODS

A literature search identified articles involving operative management of nonsyndromic sagittal synostosis. Comparison of 2 operative techniques was required, and methodology was assessed via the American Society of Plastic Surgeons' Levels of Evidence. Three techniques were considered: CVR, SC, and SMC. Meta-analysis was conducted for change in cephalic index (CI), reported as weighted mean difference (WMD). Pooled subgroup comparisons were performed for operative time, length of stay, blood loss, and cost.

RESULTS

Twelve studies providing level 2 or 3 evidence were included. All studies involved CVR (n = 187), 8 involved SC (n = 299), and 7 involved SMC (n = 158). Head-to-head comparison of change in CI demonstrated a greater, yet statistically insignificant change for CVR versus SMC, WMD = 0.94 (-0.23 to 2.11) (P = 0.12, I(2) = 55%). Calvarial vault remodeling showed a statistically greater change in CI versus SC, WMD = 1.47 (0.47-2.48) (P = 0.004, I(2) = 66%). Compared with SMC/SC, CVR had longer operative length (170 vs 97 minutes), higher blood loss (238 vs 47 mL), longer length of stay (5.1 vs 2.9 days), and higher costs ($35,280 vs $13,147), all with P < 0.0001.

CONCLUSIONS

This study, the first meta-analysis comparing 3 primary operations for correcting nonsyndromic sagittal synostosis, demonstrates no difference in CI for CVR versus SMC and a small but statistically greater improvement in CI favoring CVR over SC. Secondary outcomes favored SC/SMC procedures over CVR. However, long-term studies are still needed to adequately assess the risk-benefit ratios.