Neurocranial suture autotransplantation and periosteal dura stripping to provide a passive growth site in craniosynostosis--a case report

Application of Laser Capture Microdissection to Craniofacial Biology: Characterization of Anatomically Relevant Gene Expression in Normal and Craniosynostotic Rabbit Sutures

OBJECTIVE

Fusion of the cranial sutures is thought to depend on signaling among perisutural tissues. Mapping regional variations in gene expression would improve current models of craniosynostosis. Laser capture microdissection (LCM) isolates discrete cell populations for gene expression analysis. LCM has rarely been used in the study of mineralized tissue. This study sought to evaluate the potential use of LCM for mapping of regional gene expression within the cranial suture.

DESIGN

Coronal sutures were isolated from 10-day-old wild-type and craniosynostotic (CS) New Zealand White rabbits, and LCM was used to isolate RNA from the sutural ligament (SL), osteogenic fronts (OF), dura mater, and periosteum. Relative expression levels for Fibroblast Growth Factor 2 (FGF2), Fibroblast Growth Factor Receptor 2 (FGFR2), Transforming Growth Factor Beta 2 (TGFβ-2), Transforming Growth Factor Beta 3 (TGFβ-3), Bone Morphogenetic Protein 2 (BMP-2), Bone Morphogenetic Protein 4 (BMP-4), and Noggin were determined using quantitative real-time PCR.

RESULTS

A fivefold increase in TGFβ2 expression was detected in the CS SL relative to wild type, whereas 152-fold less TGFβ-3 was detected within the OF of CS animals. Noggin expression was increased by 10-fold within the CS SL, but reduced by 13-fold within the CS dura. Reduced expression of FGF2 was observed within the CS SL and dura, whereas increased expression of FGFR2 was observed within the CS SL. Reduced expression of BMP-2 was observed in the CS periosteum, and elevated expression of BMP-4 was observed in the CS SL and dura.

CONCLUSIONS

LCM provides an effective tool for measuring regional variations in cranial suture gene expression. More precise measurements of regional gene expression with LCM may facilitate efforts to correlate gene expression with suture morphogenesis and pathophysiology.

Suture Autotransplantation and Dural Stripping for Craniosynostosis: A Long-Term Growth Study in Humans

OBJECTIVE

Craniosynostosis treatment by suture autotransplantation and dura stripping has proven to be successful in animals. When applied clinically, it may reduce operative morbidity and postoperative growth disturbances known to occur after radical remodeling. It may prevent resynostosis, which is known to occur after simple synostostectomy. It may prevent subcutaneous fluid collections known to occur after synostectomy and dura stripping.

STUDY DESIGN

Four synostostic infants have been treated using this concept and followed up by computerized scans. The distance between markers on each side of the transplanted sutures (6 in total) has been monitored from 1.5 to 7 years.

RESULTS

The transplanted suture areas remained intact, and the sutures remained patent and experienced growth. A fifth patient with similar results was published earlier as a case report.

CONCLUSIONS

Suture transplantation and dural stripping should be further studied in future multicenter studies with larger series, comprising syndromic and nonsyndromic synostosis patients.

3D visualization and simulation of frontoorbital advancement in metopic synostosis

OBJECTIVES

Current multislice computed tomography (CT) technology can be used for diagnosis and surgical planning applying computer-assisted three-dimensional (3D) visualization and surgical simulation. The usefulness of a technique for surgical simulation of frontoorbital advancement is demonstrated here in a child with metopic synostosis.

MATERIALS AND METHODS

Postprocessing of multi-slice CT data was performed using the software 3D slicer. 3D models were created for the purpose of surgical simulation. These allow planning the course of the osteotomies and individually placing the different bony fragments by an assigned matrix to simulate the surgical result. Photo documentation was obtained before and after surgery. Surgical simulation of the procedure allowed determination of the osteotomy course and assessment of the positioning of the individual bony fragments.

CONCLUSIONS

Computer-assisted postprocessing and simulation is a useful tool for surgical planning in craniosynostosis surgery. The time-effort for segmentation currently limits the routine clinical use of this technique.