Reconstructive Options and Outcomes in Primary vs. Secondary Mandibular Reconstruction

The challenge of mandibular reconstruction is potentially increased in secondary reconstructive procedures as a result of scarring, wound bed contamination, and the greater likelihood of prior radiotherapy. Recipient vessels for microanastomosis may be more likely to be obliterated or encased in scar tissue. However, few reports have attempted to compare reconstructive options and their outcomes with respect to primary vs. secondary mandibular reconstruction. The authors' hypothesis was that factors specific to secondary mandibular reconstruction may increase the risk of flap failure and other postoperative complications, compared with primary reconstruction.

A retrospective chart review was performed on 110 patients who underwent primary mandibular reconstruction and 39 patients who received secondary reconstruction. The demographic and past medical history of the patients was well-matched; there was no statistically significant difference in patient age, therapy, or chemotherapy. However the mandibular defects of the secondary reconstruction group were larger in size and more challenging in location, with a significantly higher (p =ߙ0.018) proportion of secondary defects involving the condyle (12.8% vs. 6.4%) or the central portion of the mandible (15.4% vs. 2.6%). The greater diversity of defects was reflected by a significantly higher (p =ߙ0.03) use of non-fibula osseous free flaps to reconstruct secondary defects, although the vascularized fibular flap was the most common flap used in both primary (80%) and secondary (69%) reconstructions. Despite the additional complexity of secondary reconstruction, the complication rates were surprisingly similar. There was no significant difference in the number of patients who experienced one or more complications. The primary reconstruction group had a higher proportion of early complications such as partial or total flap loss that required additional surgery than those who underwent secondary reconstruction (28.2% vs. 20.5%). Late complications such as plate fracture or osteoradionecrosis were more common in the secondary group (28.2% vs. 17.3%).

Despite more challenging defects and scarred operative fields in secondary mandibular reconstruction, compared to primary reconstruction, success can be achieved utilizing a broader repertoire of osseous free flaps. Preoperative radiation therapy does not appear to have an effect on outcome. Early complications, including flap loss, actually occur less frequently in the secondary reconstruction, but success in long-term survivors is compromised by later complications.