PMC8685218_01
Midface defect, immediate temporary reconstruction, and two-step patient specific planning. (A) Intraoperative aspect of exposed ameloblastic carcinoma of the left hemimaxilla prior to resection. (B) Left hemimaxillectomy specimen with preservation of midface soft tissue and missing inner nasal lining (mucosa). (C) Intraoperative situation after PEEK implantation with obturator prosthesis. (D) Ectopic prevascularization by surgical insertion of an arteriovenous (AV) bundle (serratus branch of the thoracodorsal vessel) and wrapping of the construct into a split latissimus muscle. (E) CAD-CAM reconstruction on the patients CT scan showing the customized Tutoplast  scaffold with the tunnel planned for the serratus AV bundle and its branching after implantation.
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The defect was replaced with a palatal obturator prosthesis ( Figures 1A-C ), which gave an unsatisfactory functional result. The orbital floor has been reconstructed with a titanium mesh (Synthes) during primary ameloblastoma resection. The patient suffered from recurrent infections and had problems drinking water due to insufficient separation of the oral and nasal cavity. The patient's treatment consisted of a two-step reconstructive plan, namely, an ectopic implant prefabrication ( Figure 1D ), followed by its orthotopic transfer ( Figure 1E ). Tutogen Medical, Neunkirchen, Germany) with a porosity of approximately 60% was used. The scaffold, with a total volume of 27.6 cm3, was designed as a set of four pieces, which could be intraoperatively assembled and fixed with preheated absorbable pins, leaving space for a central tunnel to allow for the intraoperative insertion of an AV bundle ( Figure 1E ,  Figure 2B ).
Graft prefabrication and histological analysis (bone biopsy at moment of transfer at week 32) and volume assessment over time. (A) 3D scaffold of devitalized bone manufactured to match the patient's defect size and shape and seeded with SVF cells and BMP-2. (B) Ectopic implantation with serratus AV bundle. (C, D) Construct with vascular pedicle before and after being wrapped in split latissimus muscle. (E, F) High magnification of representative figures of bone biopsy after staining with Masson Trichrome. The Tutoplast  scaffold is characterized by purple staining, representing mature bone and cellular lacunae (white arrowheads), showing devitalized bone tissue. Newly formed bone tissue, represented by light green color, is deposited on the Tutoplast  scaffold and contains nuclei (pink arrowheads). The yellow dashed line delineates the original scaffold material and apposition of newly formed bone. A vessel (red circle) demonstrates that the scaffold is vascularized. (G) Overview figure shows appositional bone growth on the Tutoplast  scaffold (asterisk). Osteocytes (arrows) are visible in the newly formed bone. The proportion of scaffold vs. new bone formation is close to 50:50. A blood vessel is present within the newly formed bone (yellow circle). Osteoclasts (full arrowheads) fringe the Tutoplast  scaffold (asterisks), which shows clear signs of degradation at site of interaction. There is no major osteoclast infiltration at the level of the newly formed apposed bone and no sign of degradation visible. (H) CT-reconstruction and volume calculation show volume decrease over time.
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Tutogen Medical, Neunkirchen, Germany) with a porosity of approximately 60% was used. The scaffold, with a total volume of 27.6 cm3, was designed as a set of four pieces, which could be intraoperatively assembled and fixed with preheated absorbable pins, leaving space for a central tunnel to allow for the intraoperative insertion of an AV bundle ( Figure 1E ,  Figure 2B ). Figure 2A ). Following SVF cell seeding, a distally ligated arteriovenous (AV) bundle (serratus branch of the thoracodorsal vessels) was surgically inserted in the central scaffold tunnel for axial prevascularization ( Figure 2B ). The whole construct was wrapped in a split latissimus dorsi muscle flap and placed under the patient's left breast ( Figures 2C, D ).