Digital procedure preparation, 3D printing boost the maxillectomy

In a retrospective study, researchers led by Dr. Eric Moore notes that a group of patients who received virtual surgery planning with 3D printed models for maxillectomies that required microvascular reconstruction had a much lower rate of lateral rhinotomy than a cohort of similar treated patients prior to adopting these methods.

“Preoperative [virtual surgical planning]The use of 3D printed models and cutting guides as well as the intraoperative fixation of the reconstruction on the model can eliminate the use of [lateral rhinotomy] for even extensive reconstruction of the maxillectomy, “they wrote.” [lateral rhinotomy] may decrease the rate of maxillectomy-related complications. “

Although a transoral approach to performing a maxillectomy can be used, the researchers believe this technique can be challenging. As a result, they wanted to evaluate the usefulness of virtual surgical planning and 3D models in patients undergoing full and partial maxillectomy reconstruction.

They retrospectively examined 38 patients who underwent a maxillectomy with free flap reconstruction between January 1, 2008 and October 3, 2019 at their tertiary academic medical center. Of the 38 patients, 15 received a maxillectomy without virtual surgical planning while 23 underwent procedures but after the facility took over virtual surgical planning and the use of 3D printed models.

In this procedure, surgical planning meetings are held with the radiologist to review high-resolution CT images of the maxilla and the donor site on the free flap. After the surgeon and radiologist discuss the reconstruction goals, the radiologist transmits the images to the on-site anatomical modeling laboratory. Next, the images are imported into the Mimics software (Materialize) and segmented to separate the various anatomical structures.

Created from these segmentations, a virtual 3D anatomical model with several parts is exported to a stereolithographic file. Finally, Materalise’s 3-Matic software is used for any post-processing required before the 3D model is printed using various liquid polymers on a PolyJet Connex 350 3D printer (Stratasys).

According to the researchers, cutting guides are produced in a process similar to the 3D model in order to enable precise placement and alignment of the osteotomies on the upper jaw and on the bone of the reconstruction flap.

“These cutting guides are an essential part of the planning and execution to enable the avoidance of a lateral rhinotomy,” the authors wrote.

The sterilized model and cutting guides are brought to the operating room.

Advantages of virtual operation planning and 3D models for maxillectomies
Before accepting the virtual operation planning After accepting the virtual operation planning
Patients who needed a lateral rhinotomy 12 (80%) 1 (4%)
Patients with lateral rhinotomy complications 6 (50%) 0

In other results, the researchers found that there was no flap failure in the group of patients who received a lateral rhinotomy, only flap failure in patients who had not undergone the procedure.

“This study suggests that [virtual surgical planning] can aid in the planning, execution, placement and fixation of a complex free flap reconstruction of a maxillectomy defect through a transoral minimally invasive approach, “the authors wrote.

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