Monday, November 3, 2008 - 7:22 AM

Outcome Analysis of Our First 75 Spring Assisted Surgeries for Scaphocephaly

Christina Plikaitis, MD, Claire Sanger, DO, Steven Glazier, MD, Louis C. Argenta, MD, and Lisa R. David, MD.

Background: Since the beginning of the modern craniofacial era, the treatment of craniofacial deformities has come full circle. Initial minimally invasive surgeries such as the strip craniectomy had poor long-term results, and more aggressive operations with higher morbidity were developed that achieved superior durability. Recent trends in craniofacial surgery focus on developing less invasive techniques that achieve lasting results. Spring assisted surgery, first introduced by Claes Lauritzen in 1998, has demonstrated promising outcomes for the treatment of craniosynostosis. The purpose of this study was to assess the clinical outcome of this treatment modality in our first 75 cases, in comparison to both historical controls and patients treated during the same time interval, with standard cranial expansion techniques. Additionally, cost analysis of the two treatment protocols was performed. Materials and Methods: Children, between the age of three and six months, diagnosed and undergoing treatment for scaphocephaly were considered for this IRB approved study requiring parental consent for enrollment. Seventy-five children, 20 females and 55 males, have completed this study protocol to date. All study patients underwent cranial surgery with removal of a 1.5 cm strip of midline calvarium including the sagittal suture followed by the insertion of two 1.2 mm thick stainless steel omega shaped expanders (springs). Each spring exerted a mean force of 8 Newtons at initial placement. All patients had preoperative and postoperative skull films to measure cranial expansion and cephalic index. Spring removal was performed once complete reossification of the calvarial defect had occurred based upon clinical exam. Clinical outcome assessment included analysis of changes in cephalometric measurements and 3 dimensional laser shape and were compared to control patients treated for scaphocephaly using cranial expansion techniques during the same time interval as well as historic controls. Additionally, perioperative variables including OR time, OR blood loss, transfusion requirements, ICU stay, hospital stay, and hospital costs were compared between the two groups. Results: All of the study patients successfully underwent spring assisted surgery without significant complications. All children are reassessed on an annual basis with a mean follow up time of 46 months.  Four children underwent a secondary surgery for skin infection (1), spring malposition (1), and scars (2). No secondary surgeries for relapse were required. The mean age at the initial operation for the spring cranioplasty group was 5.7 months and 9.8 months for the cranial expansion group. Perioperative variables were significantly different between treatment groups. No transfusions were required for any spring cases.  The mean operative time was 30 minutes for spring placement. The mean hospital stay for the initial procedure was 22 hours. The second outpatient operative procedure to remove the springs was done at a mean age of 8.5 months, without any perioperative sequela. The mean operative time for the second procedure was 19 minutes with a mean hospital stay of 13 hours. Comparison of the cranial expansion technique with the two spring procedures combined still demonstrated a significant difference in blood loss, transfusion requirements and OR time.

Serial follow-up skull films showed a mean maximal spring expansion of 7.1 cm. The mean cephalic index preoperatively was 64.3 and postoperatively was 75.1, which compares favorably to published normal age matched historical controls treated with cranial expansion techniques. Additionally there was no significant difference between the postoperative cephalic index in patients treated with cranial expansion versus spring assisted surgery. Conclusion: This data supports that spring assisted surgery is a safe and effective, minimally invasive treatment for scaphocephaly.  It combines the low morbidity and operative time of a strip craniectomy with cranial expansion techniques  using an implanted spring to gradually distract the skull, acheiving an improved head shape. Our results indicate the potential for significant reduction in blood loss, operative time, ICU admission, hospital stay, and treatment costs compared to traditional cranial expansion. Our 7 years of experience with more than 75 children has shown spring assisted surgery is able to effectively correct cranial shape abnormalities including frontal bossing, and maintain cephalic index.   Long term 3D scanning analysis demonstrates these outcomes are maintained over time.