Virtual Surgical Planning in Subscapular System Free Flap Reconstruction of Midface Defects

Abstract

Objectives: Reconstruction of the midface has many inherent challenges, including orbital support, skull base reconstruction, optimizing midface projection, separation of the nasal cavity and dental rehabilitation. Subscapular system free flaps (SF) have sufficient bone stock to support complex reconstruction and the option of separate soft tissue components. This study analyzes the effect of virtual surgical planning (VSP) in SF for midface on subsite reconstruction, bone segment contact and anatomic position.

Materials and methods: Retrospective cohort of patients with midface defects that underwent SF reconstruction at a single tertiary care institution.

Results: Nine cases with VSP were compared to fourteen cases without VSP. VSP was associated with a higher number of successfully reconstructed subunits (5.9 vs 4.2, 95% CI of mean difference 0.31-3.04, p = 0.018), a higher number of successful bony contact between segments (2.2 vs 1.4, 95% CI of mean difference 0.0-1.6, p = 0.050), and a higher percent of segments in anatomic position (100% vs 71%, 95% CI of mean difference 2-55%, p = 0.035). When postoperative bone position after VSP reconstruction was compared to preoperative scans, the difference in anteroposterior, vertical and lateral projection compared to the preoperative 'ideal' bone position was <1 cm in 82% of measurements. There were no flap losses.

Conclusion: VSP may augment SF reconstruction of the midface by allowing for improved subunit reconstruction, bony segment contact and anatomically correct bone segment positioning. VSP can be a useful adjunct for complex midface reconstruction and the benefits should be weighed against cost.

Keywords: Cutting guides; Dental implants; Free tissue flaps; Head and neck neoplasms; Maxillectomy; Midface reconstruction; Orbital surgery; Scapula free flap; Subscapular system; Virtual surgical planning.