Functional Outcomes of Complex Mandibular Reconstruction with Osteocutaneous Fibula Free Flap with or without CAD/CAM-assisted, Virtual Surgical Simulation and Planning: A Retrospective Analysis of 246 Cases

Presentation: AHNS-020
Topic: Reconstructive
Type: Oral
Date: Wednesday, May 1, 2019
Session: 3:15 PM - 4:00 PM Scientific Session 3 - Reconstructive Advances I
Authors: Jamie A Ku, MD1, Alexander Mericli, MD2, Jun Liu, PhD2, Patrick Garvey, MD, FACS2
Institution(s): 1Cleveland Clinic, 2MD Anderson Cancer Center

AIMS/OBJECTIVES:  Osteocutaneous free fibula flap has become the mainstay for the reconstruction of complex oncologic mandibulectomy defects, although the surgery remains to be challenging, with many surgical fields often compromised by prior surgery and/or radiation therapy. Computer-aided design and manufacturing (CAD/CAM)-assisted virtual surgical planning (VSP) have allowed surgeons to attempt more accurate mandibular resections and reconstruction. We hypothesized that CAD/CAM-assisted VSP technique has resulted in improved long-term functional outcomes with reduced long-term complications compared to conventional free fibula flap mandible reconstruction.

MATERIALS/METHODS:  A retrospective review was performed, to identify all patients undergoing free fibula flap mandibulectomy reconstruction from 2005 to 2016.  Functional outcomes, including speech intelligibility, diet, gastrostomy-tube dependence, radiologic-evidence of bony union, and dental implantation were assessed at 6 months or beyond after surgery, as were the long-term plate-related complications and radiologic bony union outcomes.

RESULTS:  We identified 246 consecutive mandibulectomy patients; 59 were reconstructed with the VSP technique whereas 187 were reconstructed with a free fibula flap designed in the conventional, intraoperative fashion. The mean follow-up time was 24 months. There was no significant difference in the patient characteristics, including demographics, comorbidities, prior treatment, and intraoperative characteristics, with one exception that VSP group had less active smokers (11.3% vs 23%; p=0.03). The majority of patients had excellent long-term speech intelligibility on a scale of 1-3 (1 is <50%, 2 is 50-80%, 3 is >80%), with 85% of patients scoring 3. The VSP group had better speech intelligibility (3.0±0.2 vs 2.8±0.5 where; p=0.005) compared to the conventional group. Majority of patients achieved normal or near-normal diet (35% with soft diet, 40% with regular/solid diet), with a gastrostomy-tube dependence rate of 17.6%. There were no difference in the type of diet (VSP vs conventional: 3.9% vs 8.4% NPO, 9.6% vs 15.7% liquid/puree, 30.8% vs 36.7% soft, 50.0% vs 37.3% regular/solid; p=0.148)  or gastrostomy-tube dependence (11.9% vs 20.3%; p=0.148) between the two groups. VSP was associated with significantly fewer plate removals (3.4% vs 12.8%; p=0.048); plate fractures and exposures were similar between the two groups. There were no differences in the radiologic rate of nonunion/malunion (VSP 31.4% vs conventional 31.7%; p=0.916) or the rate of dental implantation (VSP 17.1% vs conventional 19.3%; p=0.692).

CONCLUSION:  Compared to the conventional surgical technique, CAD/CAM-assisted mandibular reconstruction with the free fibula flap is associated with superior speech intelligibility and fewer complications resulting in plate removal.