The NYU Experience with Free Fibula Reconstruction of the Mandible Utilizing Virtual Surgical Planning
Franco, Peter B. DMD; Avraham, Tomer MD; Levine, Jamie P. MD FACS; Hirsch, David L. MD DDS FACS
Statement of the Problem: The use of free osseous flaps has become the gold standard for reconstruction of complex mandibular defects. Popularized by Hidalgo1 in 1989 the free fibula transfer has become the operation of choice for these indications. While this operation has become routine; contouring of the flap using wedge osteotomies, as well as its inset remain operator dependent and imprecise. At our institution we have attempted to make this process more uniform and reproducible through the use of virtual planning and pre-fabricated cutting jigs. We have previously reported our experience on computer aided design and manufacturing;2 however the purpose of this study was to review our series of free fibula mandibular reconstructions using these adjunctive technologies.
Methods: Prior to surgery all patients underwent CT scanning of the face and bilateral lower extremities. These images were then transmitted to an outside vendor. In consultation with both the ablative and reconstructive teams, a surgical plan was devised and performed virtually, cutting jigs for both creation of the mandibular defect and for fibular osteotomies were fabricated, and a stereolithic model that allows for precise pre-surgical bending of a reconstruction plate was created. The rest of the surgical procedure was performed in standard fashion. Following IRB approval, all cases between 2009 and 2012 were identified and retrospectively reviewed. In addition to patient demographics, the charts were reviewed for surgical indications, microvascular anastomoses, use of a skin paddle, use of a “double barrel”, timing of dental implant placement (immediate versus delayed), and timing of dental prosthetic rehabilitation (immediate versus delayed).
Methods of Data Analysis: This was a retrospective chart review from 2009 to the present. Fifty four reconstructions were identified as having undergone presurgical virtual planning and subsequent surgery for mandibular reconstruction with microvascular free fibula transfer. Patient demographics and case variables were analyzed.
Results: Fifty four reconstructions were performed in 52 patients. Patients were evenly divided between a private, university affiliated medical center and a large county hospital. The most common indications were malignancy (45%), ameloblastoma (24%), osteonecrosis/osteomyelitis (20%), and congenital defects (8%). Sixty-six percent of patients were male with an average age of 44 (range 10-77). Thirty percent of patients had irradiation of the recipient site and 38% had previous surgery in said site. A skin paddle was utilized in 85% of cases, and additional osteotomies to create a “double barrel segment” were performed 25% of the time. Fifty-two percent of patients received dental implants into the fibula flap, with 43% achieving dentition with dentures. Postoperative imaging demonstrated excellent precision and accuracy of flap positioning. Three of fifty four (5.6 %) presurgical plans required a traditional approach to reconstruction. Using these presurgical virtual planning techniques we have had a 93% success rate of our free fibular flap reconstructions.
Conclusions: Pre-operative virtual planning along with use of prefabricated cutting jigs allows for precise contouring and positioning of microvascular fibular free flaps in in mandibular reconstruction. Employing this technique in over fifty patients we have been able to achieve excellent outcomes with many patients achieving dentition. While we feel that this technology facilitates reconstruction, prospective trials are necessary to establish superiority to previously employed techniques.
References:
- Hidalgo, DA Fibula free flap: A new method of mandible reconstruction Plast Reconstr Surg, 1989 Jul: 84(1) 71-9
- Levine, JP; Patel, A; Saadeh, PB; Hirsch, DL; Computer-Aided Design and Manufacturing in Craniomaxillofacial Surgery: The New State of the Art; J Craniofac Surg. 2012 Jan; 23(1): 288-93