Sunday, October 10, 2004

Endoscopic Monobloc with Piezoelectric Osteotomy

Christopher B. Gordon, MD, Enrique Ochoa Lopez Diaz, MD, X Pilar Reyna Rodriguez, DDS, Angel Puente Sanchez, MD, RA Maercks, MD, and Leopoldo Landa, MD, DMD.

PURPOSE: To develop a minimally invasive method for correcting syndromic craniosynostosis using a combined regimen of piezoelectric osteotomies and external distractors, to minimize morbidity associated with conventional approaches.

MATERIALS AND METHODS: Based upon previous anatomic studies in cadavers, (Tutino, et al) six patients with syndromic craniosynostosis from the Craniofacial Surgery Service of the Hospital Infantil de Mexico were treated with novel monobloc osteotomy. This was performed with a combination of intracranial endoscopy and an ultrasonic osteotome (Biomet, Warsaw, IN; or Synergetics, St. Charles, MO), combined with conventional transconjunctival orbital osteotomy and pterygomaxillary dysjunction. Some limited barrel-stave osteotomies and bony contouring were performed to enhance aesthetic correction. After completion of osteotomies, the midface was disimpacted with modified lamina spreaders and Gillies forceps. External midface distractors (KLS RED II, Jacksonville, FL) were applied with percutaneous screw fixation. A transfacial Steinman pin was passed percutaneously through the zygomatic bodies bilaterally to prevent facial bipartition. Distraction was carried out at 1mm/day until previously calculated limits were reached. Distractors were left to consolidate for approximately 6 weeks.

RESULTS: Mean patient age was 4 years. Four patients had Crouzon syndrome, one had Apert syndrome, and one had Pfeiffer syndrome. All osteotomies were able to be completed through limited incisions and trephines. Mean operative time was 6.25 hours. Mean midface distraction at infraorbitale was 27 mm. There was no incidence of dural laceration, visual impairment, significant hemorrhage which required open craniotomy, meningitis, infection, or intracranial hypertension. EBL averaged 630 ml. Hospital stay averaged 6 days, with 3 day ICU stay.

CONCLUSION: This demonstrates the technical feasibility of a minimally invasive approach to monobloc osteotomy. Although current generation ultrasonic osteotomes arenít purpose-built for this application, they have adequate power to cut cranial bone in young patients, minimizing the risk of dural injury. By limiting dissection, the entire bony fragment remains vascularized, providing a theoretical improvement in callus formation and stability. With this hybrid approach, many of the limitations of the original design can be avoided.