Scapular Flap for Maxillectomy Defect Reconstruction and Preliminary Results Using Three-Dimensional Modeling

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1 The Laryngoscope VC 2016 The American Laryngological, Rhinological and Otological Society, Inc. Scapular Flap for Maxillectomy Defect Reconstruction and Preliminary Results Using Three-Dimensional Modeling Mara C. Modest, MD; Eric J. Moore, MD; Kathryn M. Van Abel, MD; Jeffrey R. Janus, MD; John R. Sims, MD; Daniel L. Price, MD; Kerry D. Olsen, MD Objectives/Hypothesis: Discuss current techniques utilizing the scapular tip and subscapular system for free tissue reconstruction of maxillary defects and highlight the impact of medical modeling on these techniques with a case series. Study Design: Case review series at an academic hospital of patients undergoing maxillectomy 1 thoracodorsal scapula composite free flap (TSCF) reconstruction. Three-dimensional (3D) models were used in the last five cases. Methods: 3D modeling, surgical, functional, and aesthetic outcomes were reviewed. Results: Nine patients underwent TSCF reconstruction for maxillectomy defects (median age 5 43 years; range, years). Five patients (55%) had a total maxillectomy (TM) 6 orbital exenteration, whereas four patients (44%) underwent subtotal palatal maxillectomy. For TM, the contralateral scapula tip was positioned with its natural concavity recreating facial contour. The laterally based vascular pedicle was ideally positioned for facial vessel anastomosis. For subtotal-palatal defect, an ipsilateral flap was harvested, but inset with the convex surface facing superiorly. Once 3D models were available from our anatomic modeling lab, they were used for intraoperative planning of the last five patients. Use of the model intraoperatively improved efficiency and allowed for better contouring/plating of the TSCF. At last follow-up, all patients had good functional outcomes. Aesthetic outcomes were more successful in patients where 3D-modeling was used (100% vs. 50%). There were no flap failures. Median follow-up >1 month was 5.2 months (range, months). Conclusions: Reconstruction of maxillectomy defects is complex. Successful aesthetic and functional outcomes are critical to patient satisfaction. The TSCF is a versatile flap. Based on defect type, choosing laterality is crucial for proper vessel orientation and outcomes. The use of internally produced 3D models has helped refine intraoperative contouring and flap inset, leading to more successful outcomes. Key Words: Scapula composite flap, maxillectomy defect, reconstruction, free-flap, microvascular free-flap, scapula flap, three-dimensional modeling. Level of Evidence: 4. Laryngoscope, 127:E8 E14, 2017 INTRODUCTION Maxillectomy defects create unique challenges for the reconstructive surgeon, often involving bony and soft tissue components of the midface. Aesthetically, the bony midface helps support the orbital contents and facial contour, isolates the nose from the oral cavity, and serves as the foundation for upper dentition. Functionally, it is required for mastication, speech, and a patent airway. Reconstruction must take these multiple factors into account, with success dependent on accurate three-dimensional (3D) conceptualization of both extirpation and reconstruction. Options include prosthetic obturators, locoregional flaps, and microvascular free-flaps. 1 The thoracodorsal scapula composite free-flap (TSCF) has been described in the literature for radical maxillectomy Additional Supporting Information may be found in the online version of this article. From the Department of Otorhinolaryngology Head and Neck Surgery, Mayo Clinic, Rochester, Minnesota, U.S.A. Editor s Note: This Manuscript was accepted for publication September 12, The authors have no funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Eric J. Moore, MD, 200 1st SW, Rochester MN moore.eric@mayo.edu DOI: /lary E8 defects. It provides bone, skin, and muscle to aid in the reconstruction and can be used for a wide variety of maxillectomy defects, including those with retained orbital contents. 2,3 During planning, it is important to consider TSCF laterality to optimize vessel placement and reach. More recently, 3D models have become available to help surgeons plan reconstruction for complex cases such as those involving maxillectomy defects. The use of 3D models has been shown to decrease operative time and improve efficiency in mandibular defects. 4 The same benefits can be applied to its use for complex maxillectomy defects, aiding in designing, contouring, and plating when insetting the TSCF. Although the use of the TSCF has been well described in the literature, little has been published regarding the importance of flap laterality and the use of 3D modeling for planning and surgical execution. Herein, we present our experience at a tertiary care center using the TSCF for reconstructing maxillectomy defects in nine cases, and describe how 3D modeling has impacted outcomes. MATERIALS AND METHODS Institutional review board approval was obtained for this study (IRB: ). We performed a retrospective chart review examining all patients with reconstruction of subtotal or

2 total maxillectomy defect 6 orbital exenteration using the TSCF at the Mayo Clinic in Rochester, Minnesota (January 1, 2013 March 1, 2016). Internally produced 3D-printed models were used in five of the cases. Surgical techniques, clinical outcomes, and complications were reviewed. For patients where a 3D model was created, highresolution computed tomography (CT) scans were performed of the head and neck as well as the scapula. For reconstruction of maxillectomy defects, there are three main stages: planning, modeling, and surgical. At the start of the planning stage, the radiologist is informed prior to any imaging studies allowing them to tailor the study to produce the most accurate model. Decisions are made such as CT technology, dual-energy CT/ computed tomography angiography or multienergy scanning, unique metal reduction artifact algorithms, the possible need for magnetic resonance imaging/magnetic resonance angiography, and patient positioning mimicking that in the operating suite. The surgeon and radiologist meet and review the specific case along with reconstruction goals. At this time, the surgeon confirms which laterality of the TSCF would be best suited for optimal vessel placement and reach. During the modeling stage, the radiologist transfers the images to the anatomic modeling lab on site, and imports them into Mimics software (Materialise, Leuven, Belgium). The imaging data are segmented allowing different anatomic structures such as bone, vessels, tumor, brain, and soft tissues of the neck to be separated. A virtual 3D anatomic model is created containing several parts. This is exported into a stereolithography (STL) file that then undergoes any needed postprocessing in 3-Matic software (Materilise). The models are then exported as new STL files into Objet Studio (Stratasys, Eden Prairie, MN) to be placed on a build tray. Lifesize models are printed using varied liquid photopolymers that allow multicolor, multiple flexibility, and clear versions using a PolyJet Connex 350 3D-printer (Stratasys). Lastly, during the surgical stage, the sterilized model is brought into the operating room to help with reconstruction (Fig. 1) (see Supporting Information, Video 1, in the online version of this article for an example of the intraoperative use of a 3D model). RESULTS Patient Demographics Nine patients underwent subtotal or total maxillectomy with reconstruction using the TSCF between 2013 and The median age was 43 years (range, years), and 67% were male (n 5 6). Indication for maxillectomy included squamous cell carcinoma (33.3%, n 5 3), sarcomatoid carcinoma (22.2%, n 5 2), adenoid cystic carcinoma (11.1%, n 5 1), giant cell granuloma (11.1%, n 5 1), invasive fungal sinusitis in the setting of neutropenia during treatment for lymphoma (11.1%, n 5 1), and gunshot trauma (11.1%, n 5 1). Three patients (33.3%) presented to our clinic with a defect already present, having undergone resection elsewhere, who were seeking further reconstructive options. Details for each patient can be found in Table I. Intraoperative Details Each patient is positioned and draped for easy transition from tumor extirpation to reconstruction. The patient s back is prepped from shoulder to buttocks with the patient seated awake on the operating room table. The patient is then laid supine on a sterile drape and Fig. 1. (A) Three-dimensional printed model for a patient with subtotal maxillectomy defect prior to replications of maxillectomy defect. (B) Replication of defect onto model with harvested TSCF. (C) Plating of TCSF to model with defect to allow for prebending of plates prior to flap inset. TSCF 5 thoracodorsal scapula composite free flap. intubated. The remainder of the surgical site, including the chest, arm, and axilla are prepped and draped. This allows for transition from extirpation to flap harvest without redraping. The patient is positioned in a halflateral decubitus position, which allows for a two-team approach. In eight patients, a tracheostomy was performed, and a nasogastric feeding tube was placed in all patients and secured to the nasal septum. A standard TSCF harvest technique is used following tumor extirpation, which has been well described in E9

3 TABLE I. Summary of Patients in the Current Series. Patient No. Date of Surgery Age/Sex Indication Extent of Maxillectomy Orbital floor Reconstruction Orbital Exenteration Side of TSCF 3D Model Used Time to Decannulation (d) Time to Oral Diet (d) Flap Failure Endosseous Implantation Radiation Chemo Required Additional Procedure Procedure Performed Follow-up (d) 1 3/13 48/M SCC* Total Y N IPSI N 5 22 N N N N Y (1) Facial suspension, canthoplasty, endonasal orbital plate recontouring 2/2 plate exposure; (2) Lower lid recontouring, facial suspension 2 9/13 59/M SCC* Total Y N CONTRA N N N N N N NA /13 32/F Invasive fungal sinusitis 4 6/15 43/M Sarcomatoid carcinoma 5 6/15 28/F Giant cell tumor 6 10/15 19/M Gunshot wound 7 1/16 33/F Adenoid cystic carcinoma Subtotal N N IPSI N 5 28 N Y N N N Plan for rhinoplasty in the near future Total Y N CONTRA N 5 12 N N Y Y N NA 188 Subtotal N N IPSI Y 0 54 N Y N N N NA 155 Subtotal N N IPSI Y 5 15 N Y N N N NA 84 Subtotal N N IPSI Y 4 15 N N Y N N NA /16 54/M SCC* Total Y N CONTRA Y 4 19 N N Y N N NA /16 66/F Sarcomatoid carcinoma Total N Y CONTRA Y 6 NA N N Y Y N NA D 5 three-dimensional; CONTRA 5 contralateral; F 5 female; IPSI 5 ipsilateral; M 5 male; N 5 no; NA 5 not applicable; SCC 5 squamous cell carcinoma; TSCF 5 thoracodorsal scapula composite free flap; Y 5 yes. E10

4 Fig. 2. Scapula in its native anatomical orientation prior to harvest in relationship to both defect types (total and subtotal). Note the location of the angular artery off the thoracodorsal artery as well as the muscular attachments of the serratus and latissimus dorsi muscles. Insets: flap for total maxillectomy defect. Harvested flap with serratus and latissimus dorsi muscles used for patients who required reconstruction of all six walls of the maxilla as well as insertion of an orbital plate. Flap for subtotal defect. Harvested flap with serratus and latissimus dorsi muscles used for patient who required reconstruction of the hard palate. the literature and thus will not be reexamined here. Laterality of the flap is an important concept based on the specific defect, ensuring the donor and recipient vessels are ideally positioned for anastomosis. Once harvested and before flap inset, the flap is rotated 1808, allowingthe vessels to exit the flap laterally into the neck (Fig. 2). When a 3D model is available, following tumor extirpation and completion of the maxillectomy, the defect is replicated in the model on a back table. The intact scapula model is used in conjunction with the maxillectomy model to plan the extent of scapular tip harvest required for reconstruction (Fig. 1A). The model scapula is cut and used to mark the in situ scapula (Fig. 1B). Once the TCSF has been harvested, it is brought to the back table and contoured. The harvested flap is inset into the model to confirm adequate contouring. Plating is also first performed using the model (Fig. 1C), and once the surgeon is satisfied, the TSCF is transferred to the patient and inset into the defect. In patients with total maxillectomy defects, regardless of 3D model use, when all six walls are resected, the contralateral scapula is harvested. This requires a titanium orbital plate for orbital floor and medial wall reconstruction. We recommend doing this before flap inset, as positioning the orbital plate after scapula inset is challenging. The muscular components are positioned to reconstruct the nasal cavity and palatal defects. The superior cut surface of the scapula is inset under, and secured to, the orbital plate. The medial surface of the tip is plated to the remaining alveolus. The thicker lateral surface of the scapula tip is used to recreate the resected alveolus. The superolateral bone is plated to the zygoma and frontal process of the maxilla (Fig. 3A). In this position, the natural convexity of the scapula tip helps recreate facial contour, allowing for anastomosis with the laterally based vascular pedicle. In patients with a subtotal maxillectomy defect involving the palate, the ipsilateral scapula is harvested. A limited horizontal cervical incision is made two finger E11

5 Fig. 3. (A) Inset of contralateral flap into the total maxillectomy defect seen in a total maxillectomy defect. Note the use of the orbital plate, which is secured both to the native bony facial contour and the scapula. (B) Inset of the ipsilateral flap into a palatal defect with plates not shown. Note in both (A) and (B), donor vessels are ideally positioned for anastomosis with the laterally based facial vessels. breadths below the mandible ipsilateral to the maxillectomy defect. The facial vessels are secured for anastomosis. The TSCF is positioned either within the model defect when available or in the actual defect, ensuring adequate fit and facial projection. The scapula is plated to the zygoma bilaterally using miniplate fixation. The cut edge is positioned posteriorly and the bone convexity superiorly. The serratus muscle is used to obturate the oral cavity defect. This way the pedicle is positioned above the serratus but below the scapula tip, providing protection while also allowing the vessels to exit the flap laterally. The pedicle can then be tunneled subcutaneously through the cheek for anastomosis with the laterally positioned facial vessels (Fig. 3B). Functional Outcomes Each patient underwent a video swallow study and speech language pathology evaluation. All were advanced to a soft diet between 2 and 6 weeks postoperatively (range, days). The patient who did not start an oral diet until 54 days postoperatively required percutaneous endoscopic gastric tube placement while undergoing postoperative chemoradiation for his maxillary sinus sarcomatoid carcinoma (patient 5). Functionally, 12.5% (n 5 1/8) were tolerating a thick nectar diet at last follow-up, 37.5% (n 5 3/8) were tolerating a soft diet, and 50% (n 5 4/8) had advanced to a general diet. The median time to oral diet in the 3D model group was 17 days versus 20.5 days in the group where modeling was not used. Twenty-two percent (n 5 2) had maxillary endosseous implants placed a E12 median of 3.5 months (range 3 4 months) following the initial surgery, with additional implants placed at a median of 7 months following the initial surgery. A patient is able to wear dentures if the ipsilateral canine is preserved, but implants are preferred as they provide improved functionality. Comprehensible speech was obtained by all patients by 3 weeks following surgery (range, days). All patients were decannulated by 2 weeks following surgery(median, 5 days; range, 5 16 days). None of the patients complained of any long-term shoulder weakness or other donor-site morbidity. Aesthetic Outcomes In the group of patients (n 5 4) where 3D modeling was not used, one patient (patient 1) required two additional surgeries to address several aesthetic concerns as well as exposed hardware. He underwent an ophthalmologic procedure to correct mild enophthalmos and a facial reanimation procedure including facial suspension and canthoplasty to address facial ptosis and lower lid ectropion. This patient continues to have some mild facial ptosis even after an additional procedure including lower-lid contouring and revision facial suspension. One other patient in the group where 3D modeling was not used is unhappy with her aesthetic outcome, with plans for a rhinoplasty in the near future (patient P3). Of the five patients where 3D modeling was used, none required additional surgery for aesthetic concerns (Fig. 4). When our head and neck surgeons (n 5 3) were blinded to whether or not a patient was constructed

6 Fig. 4. Patient with excellent aesthetic and functional results 6 months after initial surgery (patient 4). using 3D modeling, the median aesthetic outcome score was better in the 3D modeling group (median score, 1 vs. 1.7). A score of 1 represented an excellent aesthetic result, whereas 3 meant the surgeon recommended additional surgical intervention to improve aesthetic outcome. Complications and Clinical Outcomes There were no microvascular flap failures, deaths, or other major complications. One patient from the group without intraoperative use of 3D modeling required immediate reexploration with reanastomosis of the thoracodorsal artery to the lingual artery in the postoperative setting (patient 2). A thrombus was discovered in the facial artery after a change in the signal output from the implantable Doppler system (Cook-Swartz Doppler probe; Cook Medical, Bloomington, IN). This patient also suffered from aspiration pneumonia requiring hospital readmission and a short stay in the intensive care unit. Three patients (33.3%) underwent postoperative radiation, whereas two patients (22.2%) underwent postoperative chemoradiation. All patients were alive at last followup, and in patients with greater than 1 month follow-up, median follow-up was 5.2 months (range, months). One patient returned to his home country and was therefore unavailable for long-term follow-up. DISCUSSION Reconstructing maxillary defects, continue to be a challenge in head and neck surgery. The method of reconstruction becomes crucial in the oncologic setting, where patients often undergo adjuvant radiation therapy. Radiation can compromise healing and lead to osteoradionecrosis or exposure of hardware. The goal is to minimize these complications by using vascularized composite osteomusculocutaneous flaps such as the TSCF, which has several advantages over other flaps for maxillectomy reconstruction. 5 The advent of 3D modeling in head and neck reconstruction has allowed surgeons to improve upon functional and aesthetic outcomes, which are crucial to patient satisfaction and can be difficult to achieve in maxillectomy defects. When planning the reconstruction of a maxillectomy defect, several components must be considered. Before addressing the functional and aesthetic aspects, the vessel position and reach of a specific flap needs to be taken into consideration, as the donor vessels are almost always found in the neck. For the TSCF, the arterial supply to the tip is consistently provided by the angular artery, a branch of the thoracodorsal artery (Fig. 2). 6 Ensuring the angular artery is included with the thoracodorsal artery during harvest of the scapular tip has specific advantages. 5,6 The angular artery can support up to 20 cm of bone from either the medial or lateral scapula, whereas the traditional circumflex artery can only support 12 cm. 5,7 Laterality of the scapula in relationship to the maxillectomy defect also needs to be taken into consideration. 8 Survival of the flap relies on successful vessel anastomoses, making it paramount to optimize anatomic orientation and minimize any torsion or kinking. When considering a left-sided total maxillectomy defect 6 orbital exenteration, the contralateral right scapula is situated such that donor vessels exit laterally, where they can be easily anastomosed to the harvested cervical vessels. This provides the least amount of torsion on the microvascular anastomosis, decreasing the risk of compression, thrombosis, and flap failure (Fig. 3A). In patients with a subtotal maxillectomy defect of the palate on the right with midline extension, the ipsilateral right scapula flap is chosen for reconstruction. This allows the donor vessels to exit the flap laterally between bone and muscular components, providing the most protection and least amount of torsion as donor vessels are tunneled through subcutaneous buccal tissue to reach the cervical vessels (Fig. 3B). Once the TSCF has been chosen as the most appropriate flap for reconstruction, and the proper laterality has been determined, the next step is reconstruction. Correctly rebuilding the orbit, nasal, and oral cavity is crucial to a patient maintaining their vision, airway, oral competence, and speech. At its most basic level, this requires successful separation of the orbital, oral, and nasal cavities. The serratus and the latissimus dorsi E13

7 muscular components can be contoured to rebuild the soft palate and fill any dead space created by resection of the lateral nasal wall or infratemporal or pterygoid fossa. By using the scapula tip to replace bony defects, one can successfully rebuild the anterior maxillary wall, orbital floor, and palate, effectively separating the orbit, nasal cavity, and oral cavity. The scapular tip as the neoalveolus also allows for future dental implantation (patients 3, 5, and 6). All nine of our patients returned to an oral diet and were tracheostomy free by 6 weeks following surgery. By recreating anatomic spaces, patients can successfully resume oral intake and achieve decannulation. The next goal is achieving acceptable aesthetic outcome. The surgeon must consider malar projection, facial width, facial expression, and eye and lid position. To address malar projection, the zygomatic process must be reconstructed as a mirror image to the contralateral side. 9 With the TSCF this is possible by taking advantage of the bony scapula s width. In more extensive maxillectomy defects, the orbital floor must also be reconstructed. Unlike the osteocutaneous radial forearm free-flap, the TSCF can provide cheek contour, support the orbital contents, and improve eye positioning when combined with an orbital plate, which should be placed prior to the scapula s inset. 10 It is during the intraoperative reconstructive planning stage that 3D modeling has become so crucial to successful outcomes, as was apparent in our series where the only two patients unhappy with their aesthetic outcome were in the group where a 3D model was not used, and the only patient who required multiple procedures to improve his aesthetic outcome occurred prior to 3D models being used at our institution (patient 1). The use of computer-aided design for creating complex 3D models has been in use for several decades, and first used in head and neck for complex oromaxillary and craniofacial reconstructive surgery. 11 Initially 3D modeling in collaboration with an outside company was used at our institution for planning mandibular defect reconstruction using the fibula free flap. 12 More recently 3D modeling moved from the engineering to radiology department, allowing for the internal production of 3D models. This has led to closer communication between surgeon and radiologist during the planning stage, faster turnaround time for model production, and lower production costs. 13 The use of a 3D model allows the surgeon to better plan the extent of resection, visualize the anticipated defect, plan the contouring of soft tissue and bony components of the flap, and confirm accurate plating of the flap to the defect in the model prior to actual flap inset. Hanasono et al. demonstrated that the use of 3D modeling for fibular reconstruction of mandibular defects results in decreased operative time (by 1.7 hours), and significant improvement in the precision of reconstruction. 4 In a survey of 10 of our surgeons involved in head and neck reconstruction, all 10 surgeons felt that 3D models improved intraoperative efficiency and precision. Total operative time was not directly compared between our 2 groups as the extent of maxillectomy with or without orbital exenteration was E14 heterogeneous and would affect operative time independent of 3D modeling use. When comparing the four patients who had maxillectomy reconstruction prior to our institution s use of 3D modeling to those where 3D modeling was employed, the time to decannulation was lower in the 3D modeling group (mean, 3.8 vs. 7.5 days), and more patients were satisfied with their functional and aesthetic outcomes (100% vs. 50%). No patients with 3D model intraoperative planning required a subsequent procedure to improve facial cosmesis. This study was limited by our small sample size, retrospective data collection, subjective outcome measures, and limited follow-up. Although we only present a small case series, given the improvement in operative efficiency as well as functional and aesthetic results, we believe our preliminary findings are a useful addition to the literature. CONCLUSION Reconstruction of maxillectomy defects can be complex. Successful aesthetic and functional outcomes are critical to patient satisfaction. The TSCF is a versatile flap that, based on defect type (total 6 orbital exenteration vs. subtotal palatal defect), should be harvested contralateral or ipsilateral, respectively, to optimize vessel orientation and outcomes. The use of internally produced 3D models has been extremely helpful in refining intraoperative contouring and flap inset for reconstructing maxillectomy defects. This in turn translates into more successful aesthetic and functional outcomes, and a more satisfied patient. BIBLIOGRAPHY 1. Andrades P, Militsakh O, Hanasono M, Rieger J, Rosenthal E. Current strategies in reconstruction of maxillectomy defects. Arch Otolaryngol Head Neck Surg 2011;137: Brown J, Bekiroglu F, Shaw R. Indications for the scapular flap in reconstructions of the head and neck. Br J Oral Maxillofac Surg 2010;48: Cordeiro P, Santamaria E. A classification system and algorithm for reconstruction of maxillectomy and midfacial defects. Plast Reconstr Surg 1999;105: Hanasono M, Skoracki R. Computer-assisted design and rapid prototype modeling in microvascular mandible reconstruction. Laryngoscope 2013; 123: Mitsimponas K, Iliopoulos C, Stockmann P, et al. The free scapular/parascapular flap as a reliable method of reconstruction in the head and neck region: a retrospective analysis of 130 reconstructions performed over a period of 5 years in a single department. 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