| Presenter: Ema Zubovic, BA, Washington University in St. Louis School of Medicine
Authors: Ema Zubovic (1), Albert Woo (2), Gary Skolnick (2), Sybill Naidoo (2), Matthew Smyth (3), Kamlesh Patel (4)
(1) Washington University in St. Louis School of Medicine, Saint Louis, MO, (2) Washington University School of Medicine, St. Louis, MO, (3) Washington University School of Medicine, St. Louis Children's Hospital, St. Louis, MO, (4) Washington University in St. Louis, St. Louis, MO
Ema Zubovic, BA
Washington University in St. Louis School of Medicine
Premature fusion of the lambdoid suture results in deformity of the cranial base characterized by deviation of foramen magnum to synostotic side, asymmetry of the petrous ridges and the external acoustic meatus, and a mastoid bulge ipsilateral to the synostosis with contralateral occipital bossing. Previous studies have shown that traditional open cranial vault remodeling does not fully address the endocranial deformity in patients with lambdoid synostosis. This study aims to compare endoscopic-assisted suturectomy with postoperative molding helmet therapy to traditional open reconstruction by quantifying changes in cranial base morphology.
Anthropometric measurements were made on pre- and 1-year postoperative three-dimensionally reconstructed computed tomography scans of 12 patients with unilateral lambdoid synostosis: 8 patients underwent open posterior cranial vault reconstruction and 4 received endoscopic-assisted suturectomy with molding helmet therapy. Cranial base asymmetry was analyzed using previously defined measures: posterior fossa deflection angle (PFA), petrous ridge angle (PRA), mastoid cant angle (MCA), and vertical and anterior-posterior (A-P) displacement of external acoustic meatus (EAM). Postoperative comparisons were made between the open and endoscopic groups.
Preoperatively, patients in the open and endoscopic groups were statistically equivalent in PFA (p=0.720), PRA (p=0.958), MCA (p=0.085), and A-P EAM displacement (p=0.591). Postoperatively, open and endoscopic patients were statistically equivalent in all measures. Mean postoperative PFA for the open and endoscopic groups was 6.61 and 6.43 degrees (p=0.939), PRA asymmetry was 6.37 and 7.56 percent (p=0.641), MCA was 4.01 and 3.18 degrees (p=0.387), vertical EAM displacement was -2.28 and -2.25 millimeters (p=0.974), and A-P EAM displacement was 6.84 and 7.75 millimeters (p=0.429).
Patients treated with both open and endoscopic repair of isolated lambdoid synostosis show persistent postoperative cranial base asymmetry. Results of endoscopic-assisted suturectomy with postoperative molding helmet therapy are similar to those of open reconstruction.