THE IN-UTERO CORRECTION OF UNILATERAL CORONAL CRANIOSYNOSTOSIS

We performed the first in utero correction of a unilateral right coron al craniosynostosis using 70-day gestation fetal lambs. The craniosyno stosis was created in eight fetuses by excising their right coronal su tures, and then placing demineralized bone powder, transforming growth factor-beta, and bone morphogenetic protein-2 into the defect. Twenty -one days later, after suture fusion had occurred, four of the eight s heep were treated with a 4 mm X 12 mm strip craniectomy to open the en tire synostosed right coronal suture. The edges of the excision were w rapped with 100-mu m-thick Gore-Tex (W. L. Gore & Associates, Flagstaf f, Ariz.) sheets to prevent bony refusion. All eight lambs then progre ssed to term (140 days). The skulls of four normal, unoperated, term l ambs were used as controls. At 140 days, all four treated lambs had a widely patent strip craniectomy site without any evidence of bone rege neration. This in utero correction led to a marked improvement in cran iofacial morphology of three of four animals when compared with the un corrected controls with significant (p < 0.01) correction in orbital p osition, skull length, and shape of the frontal bone. This was in shar p contrast to the uncorrected animals, which had marked orbital elevat ion, compression of the anteroposterior length of the cranial vault, f rontal bone flattening, and shortening of the cranial base. The fourth corrected animal also showed evidence of improvement but had some abn ormal calvarial changes secondary to the development of horns, which d isplaced the calvaria in a downward vector. We conclude that the in ut ero correction of craniosynostosis is feasible and provides a signific ant benefit by decreasing the severity of many of the associated defor mities seen with this disorder.