Comparison of CAD/CAM and conventional microvascular free bone flaps in reconstructive head and neck surgery: a retrospective analysis of over 110 cases

OBJECTIVES: Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) - techniques are increasingly considered the gold standard for orofacial osseous reconstruction. By facilitating the harvesting and transfer of microvascular bone flaps, CAD/CAM offers potential advantages over conventional methods. Therefore, this study aimed to compare both methods in a large cohort. MATERIALS AND METHODS: Patients who underwent conventional or CAD/CAM-planned osseous reconstruction with microvascular free flaps between 2000 and 2019 were included. Primary outcomes included osseous union, plate fracture, duration of intensive care (ICU) treatment, ischemic time, surgical time, oncological clearance and red blood cell transfusion requirements (RBT). Confounding factors influencing primary results were also analyzed. Statistical analyses were performed with a multivariate regression model; the level of significance was set to p = 0.050. RESULTS: A total of 112 patients were included, with 56 cases undergoing conventional reconstruction and 56 receiving CAD/CAM-assisted surgery. Patients in the CAD/CAM-group had significantly shorter ischemic times (p = 0.007), with no disadvantages regarding resection margins (p = 0.509). Nevertheless, reconstruction with scapula osteocutaneous free flaps (SOFF) and reconstruction with deep circumflex iliac artery grafts (DCIA) flaps showed a significant association (p = 0.015 and p = 0.036 respectively) for red blood cell transfusion requirements when performed with CAD/CAM. CONCLUSIONS: CAD/CAM-techniques reduce ischemic time in osseous reconstruction and show no disadvantages regarding clear margin resection. When performing complex reconstructions with chimeric SOFF using CAD/CAM-technique, longer ICU stay and prolonged surgical time was noticed. Furthermore, CAD/CAM-technique is associated with higher requirements for RBT when performing reconstructions with SOFF and DCIA flaps. Nevertheless, these results must be interpreted with caution, as the conventional group included younger patients (mean: 58.66 ± 9.15 years) than the CAD/CAM group (mean: 64.98 ± 10.41 years). CLINICAL RELEVANCE: CAD/CAM-techniques reveal advantages, such as reduced ischemic time when compared to the conventional technique and enables extensive reconstructive surgery even for older patients. Nevertheless, due to the retrospective character with heterogeneous study groups, further research is highly recommended to evaluate long-term outcomes and further define the role of CAD/CAM in oncologic head and neck reconstruction.