Characterization of the MSAP Flap in Head and Neck Surgical Oncology: A 3D Cadaveric Study.

OBJECTIVES: The medial sural artery (MSA) perforator flap is a versatile free flap. However, the cutaneous perforators are not well characterized. The objectives of this pilot anatomical study were to: (1) visualize in three-dimensions, as in-situ, the origin, course, and distribution of the cutaneous perforators, (2) characterize the number and frequency of the perforators, and (3) quantify mean pedicle length. METHODS: Thirteen cadaveric specimens were dissected, digitized, and modeled in 3D. Three-dimensional models and dissection photographs were used to determine the origin, course, number, distribution, and pedicle length of MSA perforators. RESULTS: The most common pattern consisted of three perforators (39% of specimens). The maximum number of perforators identified was four (23%). The majority of specimens (92%) had a cutaneous perforator originating from the lateral branch of the MSA and coursed most frequently in the second (43%) and third (37%) quartiles of the length of the tibia. Mean pedicle length was 19.1 ± 6.9 cm. Perforators originating from the medial branch of the MSA were significantly (p < 0.05) shorter than those from the lateral branch and were found to course only in the first quartile. CONCLUSION: The 3D models constructed in this study provide a comprehensive overview of the location and course of the perforators, enabling measurement of parameters in 3D-space. Anatomical characterization of the MSA perforator flap using 3D analysis can assist reconstructive surgeons in understanding the relevant anatomy and optimizing the surgical technique for flap harvest. LEVEL OF EVIDENCE: N/A Laryngoscope, 2024.

A 3D Analysis of Plating Strategies in Mandibular Reconstruction: A Randomized Control Pilot Study.

OBJECTIVE(S): The purpose of this study was to compare computer-assisted mandibular plating to conventional plating using quantitative metrics. METHODS: Patients scheduled to undergo mandibular reconstruction were randomized to three-dimensional modelling for preoperative plate bending or intraoperative freehand bending. Preoperative and postoperative head and neck computed tomography scans were obtained to generate computer models of the reconstruction. The overall plate surface contact area, mean plate-to-bone distance, degree of conformance, and position of the condylar head within the glenoid fossa between pre- and post-operative scans were calculated. RESULTS: Twenty patients were included with a mean age of 57.8 years (standard deviation [SD] = 13.6). The mean follow-up time was 9.8 months (range = 1.6-22.3). Reconstruction was performed with fibular (25%) or scapular free flaps (75%). The percentage of surface contact between the reconstructive plate and mandible was improved with three-dimensional models compared to freehand bending (93.9 ± 7.7% vs. 78.0 ± 19.9%, p = 0.04). There was improved overall plate-to-bone distance (3D model: 0.7 ± 0.31 mm vs. conventional: 1.3 ± 0.8 mm, p = 0.06). Total intraoperative time was non-significantly decreased with the use of a model (3D model: 726.5 ± 89.1 min vs. conventional: 757.3 ± 84.1 min, p = 0.44). There were no differences in condylar head position or postoperative complications. CONCLUSION: Computer-assisted mandibular plating can be used to improve the accuracy of plate contouring. LEVEL OF EVIDENCE: 2 Laryngoscope, 134:2182-2186, 2024.

Development and validation of a novel TNM staging N-classification of oral cavity squamous cell carcinoma.

BACKGROUND: For oral cavity squamous cell carcinoma (OSCC), extent of extranodal extension (ENE) (minor, ≤2 mm; major, >2 mm) is differentially prognostic, whereas limitations exist with the 8th edition of American Joint Committee on Cancer/International Union Against Cancer TNM N-classification (TNM-8-N). METHODS: Resected OSCC patients at four centers were included and extent of ENE was recorded. Thresholds for optimal overall survival (OS) discrimination of lymph node (LN) features were established. After dividing into training and validation sets, two new N-classifications were created using 1) recursive partitioning analysis (RPA), and 2) adjusted hazard ratios (aHRs) and were ranked against TNM-8-N and two published proposals. RESULTS: A total of 1460 patients were included (pN0: 696; pN+: 764). Of the pN+ cases, 135 (18%) had bilateral/contralateral LNs; 126 (17%) and 244 (32%) had minor and major ENE, and two (0.3%) had LN(s) >6 cm without ENE (N3a). LN number (1 and >1 vs. 0: aHRs, 1.92 [95% confidence interval (CI), 1.44-2.55] and 3.21 [95% CI, 2.44-4.22]), size (>3 vs. ≤3 cm: aHR, 1.88 [95% CI, 1.44-2.45]), and ENE extent (major vs. minor: aHR, 1.40 [95% CI, 1.05-1.87]) were associated with OS, whereas presence of contralateral LNs was not (aHR, 1.05 [95% CI, 0.81-1.36]). The aHR proposal provided optimal performance with these changes to TNM-8-N: 1) stratification of ENE extent, 2) elimination of N2c and 6-cm threshold, and 3) stratification of N2b by 3 cm threshold. CONCLUSION: A new N-classification improved staging performance compared to TNM-8-N, by stratifying by ENE extent, eliminating the old N2c category and the 6 cm threshold, and by stratifying multiple nodes by size.

An interactive augmented reality software for facial reconstructive surgeries.

BACKGROUND AND OBJECTIVE: Surgical trainees need a lot of training and practice before being able to operate independently. The current approach of surgical education mainly involves didactic teaching and psychomotor training through physical models or real tissue. Due to the unavailability of physical resources and lack of objective ways of evaluation, there is a demand for developing alternative training methods for surgeons. In this paper, we present an application that provides additional training opportunities to surgical trainees in the field of facial reconstructive surgeries. METHODS: We built a mobile augmented reality application that helps the user to visualize important concepts and experiment with different surgical plans for facial reconstructive surgeries. The application can overlay relaxed skin tension lines on a live video input or a patient's photo, which serve as bases for aligning a skin flap. A surgical trainee can interactively compare different skin flap design choices with estimated final scars on a photo of a patient. Data collection capability is also added to the application, and we performed a Monte Carlo experiment with simulated users (five classes of 100 users each) as an example of objectively measuring user performance. RESULTS: The application can overlay relaxed skin tension lines on a patient's face in real time on a modern mobile device. Accurate overlays were achieved in over 91% as well as 84% and 88% out of 263 generated face images, depending on the method. Visual comparisons of the three overlay methods are presented on sample faces from different population groups. From the Monte Carlo experiment, we see that user actions in each class follow a normal distribution with a distinct set of parameters. CONCLUSIONS: This application can serve as a basis for teaching surgical trainees the fundamentals of different facial reconstructive procedures, especially concepts related to relaxed skin tension lines and skin flaps. It can objectively evaluate the performance of surgical trainees in a course. This setup focuses on illustrating the relationship between the orientation of skin flaps and relaxed skin tension lines, which is a prerequisite of minimizing scarring in patients in addition to good surgical techniques.

The impact of surgical resection margins on outcomes for adults with head and neck osteosarcomas: A Canadian sarcoma research and Clinical Collaboration (CanSaRCC) study.

OBJECTIVE: The aim of the study is to describe the factors that influence outcome in adults with head and neck osteosarcoma (HNO) with a specific focus on the margin status. METHODS: Patients with a diagnosis of HNO between the years 1996-2021 were reviewed from the Canadian Sarcoma Research and Clinical Collaboration (CanSaRCC) Database. Baseline characteristics, pathology, treatment, and outcomes were analyzed. Univariable (UVA) and multivariable (MVA) Cox regression models were performed. 5-year locoregional control rate and overall survival (OS) were estimated using Kaplan-Meier method and Log-Rank test. RESULTS: Of 50 patients with a median age of 40 years (range 16-80), 27 (54%) were male. HNO commonly involved the mandible (n = 21, 42%) followed by maxilla (n = 15, 30%). Thirteen (33.3%) had low-intermediate grade and 26 (66.6%) had high grade tumors. Three patients (6%) had negative resection margins (>5 mm), 24 (48%) had close margins (1-5 mm), 15 (30%) had positive margins (<1mm) and 7 (16%) had unknown margin status. In total, 39 (78%) received chemotherapy - 22 (44%) received neoadjuvant chemotherapy while 17 (34%) received adjuvant chemotherapy. A total of 12 (24%) patients received radiotherapy, of whom 8 (16%) had adjuvant and 3 (6%) had neo-adjuvant. Median follow-up time was 6.3 years (range 0.26-24.9). Disease recurred in 21 patients (42%), of whom 15 (30%) had local recurrence only, 4 (8%) had distant metastasis, and 2 (4%) had both local and distant recurrence. 5-year locoregional control rate and OS was 62% and 79.2% respectively. Resection margins <3 mm was associated with lower 5 years OS and locoregional control rate (Log-Rank p = 0.02, p = 0.01 respectively). CONCLUSION: Osteosarcomas of the head and neck are rare and local recurrence remains a concern. Surgical resection with negative resection margins may improve survival, and a 3 mm resection margin threshold may optimize survival. Radiotherapy and/or chemotherapy should be considered in a multidisciplinary setting based on risk-features.

The protective role of postoperative radiation therapy in low and intermediate grade major salivary gland malignancies: A study of the Canadian Head and Neck Collaborative Research Initiative.

BACKGROUND: The objective of this study was to examine the utility of postoperative radiation for low and intermediate grade cancers of the parotid and submandibular glands. METHODS: The authors conducted a retrospective, Canadian-led, international, multi-institutional analysis of a patient cohort with low or intermediate grade salivary gland cancer of the parotid or submandibular gland who were treated from 2010 until 2020 with or without postoperative radiation therapy. A multivariable, marginal Cox proportional hazards regression analysis was performed to quantify the association between locoregional recurrence (LRR) and receipt of postoperative radiation therapy while accounting for patient-level factors and the clustering of patients by institution. RESULTS: In total, 621 patients across 14 tertiary care centers were included in the study; of these, 309 patients (49.8%) received postoperative radiation therapy. Tumor histologies included 182 (29.3%) acinic cell carcinomas, 312 (50.2%) mucoepidermoid carcinomas, and 137 (20.5%) other low or intermediate grade primary salivary gland carcinomas. Kaplan-Meier LRR-free survival at 10 years was 89.0% (95% confidence interval [CI], 84.9%-93.3%). In multivariable Cox regression analysis, postoperative radiation therapy was independently associated with a lower hazard of LRR (adjusted hazard ratio, 0.53; 95% CI, 0.29-0.97). The multivariable model estimated that the marginal probability of LRR within 10 years was 15.4% without radiation and 8.8% with radiation. The number needed to treat was 16 patients (95% CI, 14-18 patients). Radiation therapy had no benefit in patients who had early stage, low-grade salivary gland cancer without evidence of nodal disease and negative margins. CONCLUSIONS: Postoperative radiation therapy may reduce LLR in some low and intermediate grade salivary gland cancers with adverse features, but it had no benefit in patients who had early stage, low-grade salivary gland cancer with negative margins.

Cribriform adenocarcinoma of the minor salivary glands: a case report.

BACKGROUND: Polymorphous adenocarcinoma is the third most common malignant salivary gland tumor. Within polymorphous adenocarcinoma, cribriform adenocarcinoma of salivary glands is a rare subtype and resembles papillary thyroid carcinoma histopathologically. Diagnostically, cribriform adenocarcinoma of salivary glands is challenging for pathologists and surgeons alike as initial presentation and cytologic nuclear features can be easily confused with papillary thyroid carcinoma arising from a thyroglossal duct remnant or lingual thyroid. CASE PRESENTATION: A healthy 64-year-old Caucasian woman presented to a community otolaryngologist with a 4-year history of progressive postnasal drip, globus sensation, and eventual dysphonia. Flexible fiberoptic laryngoscopy showed a large, smooth, vallecular lesion filling the oropharynx. Computed tomography imaging of the neck showed a rounded heterogeneous mass centered within the right aspect of the oropharynx measuring 4.2 × 4.4 × 4.5 cm. Fine needle aspiration biopsy was suspicious for papillary carcinoma due to microscopic findings of malignant cells, nuclear grooves, and a powdery chromatin pattern. In the operating room, the tumor was resected en bloc using a lateral pharyngotomy approach with partial resection of the right lateral hyoid. A limited cervical lymphadenectomy was performed to facilitate the lateral pharyngotomy approach and two out of three lymph nodes demonstrated regional metastatic disease. Nuclear grooves, nuclear membrane notching, and occasional intranuclear pseudoinclusions were identified, which are overlapping histopathological characteristics of papillary thyroid carcinoma and cribriform adenocarcinoma of salivary glands. It was negative for thyroglobulin and thyroid transcription factor-1, which was in keeping with cribriform adenocarcinoma of salivary glands rather than papillary thyroid carcinoma. CONCLUSION: It is difficult to distinguish cribriform adenocarcinoma of salivary glands from papillary thyroid carcinoma solely by cytology, and the distinct characteristics of regional lymph node metastasis coupled with nuanced histologic differences should be emphasized in the evaluation of patients presenting with neck lymphadenopathy and an unknown primary or tongue mass. If sufficient fine needle aspiration biopsy material is available, thyroid transcription factor-1, thyroglobulin, or molecular testing may prove useful in differentiating cribriform adenocarcinoma of salivary glands from papillary thyroid carcinoma. A misdiagnosis of papillary thyroid carcinoma may lead to inappropriate treatment including unnecessary thyroidectomy. Therefore, it is critical for both pathologists and surgeons to be aware of this uncommon entity to avoid misdiagnosis and subsequent mismanagement.

Cigarette smoking cessation, duration of smoking abstinence, and head and neck squamous cell carcinoma prognosis.

BACKGROUND: Tobacco use is a major risk factor for developing head and neck squamous cell carcinoma (HNSCC). However, the prognostic associations with smoking cessation are limited. The authors assessed whether smoking cessation and increased duration of abstinence were associated with improved overall (OS) and HNSCC-specific survival. METHODS: Clinicodemographic and smoking data from patients with HNSCC at Princess Margaret Cancer Center (2006-2019) were prospectively collected. Multivariable Cox and Fine and Gray competing-risk models were used to assess the impact of smoking cessation and duration of abstinence on overall mortality and HNSCC-specific/noncancer mortality, respectively. RESULTS: Among 2482 patients who had HNSCC, former smokers (adjusted hazard ratio [aHR], 0.71; 95% CI, 0.58-0.87; p = .001; N = 841) had a reduced risk of overall mortality compared with current smokers (N = 931). Compared with current smokers, former smokers who quit >10 years before diagnosis (long-term abstinence; n = 615) had the most improved OS (aHR, 0.72; 95% CI, 0.56-0.93; p = .001). The 5-year actuarial rates of HNSCC-specific and noncancer deaths were 16.8% and 9.4%, respectively. Former smokers (aHR, 0.71; 95% CI, 0.54-0.95; p = .019) had reduced HNSCC-specific mortality compared with current smokers, but there was no difference in noncancer mortality. Abstinence for >10 years was associated with decreased HNSCC-specific death compared with current smoking (aHR, 0.64; 95% CI, 0.46-0.91; p = .012). Smoking cessation with a longer duration of quitting was significantly associated with reduced overall and HNSCC-specific mortality in patients who received primary radiation. CONCLUSIONS: Smoking cessation before the time of diagnosis reduced overall mortality and cancer-specific mortality among patients with HNSCC, but no difference was observed in noncancer mortality. Long-term abstinence (>10 pack-years) had a significant OS and HNSCC-specific survival benefit.

Cross-legged modification for medial sural artery perforator flap harvest.

When thin and pliable free tissue is needed, the medial sural artery perforator (MSAP) flap provides an excellent option with minimal donor site morbidity. However, among its pitfalls include difficult patient positioning and surgeon ergonomics throughout the harvest. We describe a novel positioning technique that may significantly improve surgeon ergonomics and ease of MSAP flap harvest. A cross-legged modification may eliminate many of the issues associated with the classic frog-leg position. While the patient is cross-legged, the surgeon is afforded a normal field of view that is closer to their body, while simultaneously providing support to the lateral side of the gastrocnemius muscle. This pictorial essay describes this positioning technique and subsequent harvest. By incorporating a more ergonomic cross-legged position during flap elevation, many of thedrawbacks of the MSAP flap could be eliminated.

Factors predicting pharyngocutaneous fistula in patients after salvage laryngectomy for laryngeal malignancy - A multicenter collaborative cohort study.

OBJECTIVES: Pharyngocutaneous fistula (PCF) is a major morbidity of salvage total laryngectomy (TL). Understanding the factors predicting PCF is fundamental to managing laryngeal cancer. We aim to assess factors associated with PCF following salvage TL in a multicenter, international retrospective cohort study of academic centers in the US and Canada. RESULTS: In total, 550 patients post-salvage TL were identified (mean [SD; range] age, 64 [10.4; 32-90] years; 465 [85 %] male and 84 [15 %] female) between 2000 and 2014. Rate of PCF was 23 % (n = 127) with median time to PCF of 2.9 weeks. Surgical management of PCF was required in 43 % (n = 54) while 57 % (n = 73) required wound care alone. Rates of PCF differed by primary treatment modality [radiation, 20 % (n = 76); chemoradiation, 27 % (n = 40); not available (n = 6)] and use of vascularized tissue in pharyngeal closure [free/regional flap, 18 % (n = 25); no vascularized tissue/primary closure, 24 % (n = 98); not available (n = 4)]. There was no statistically significant association between PCF and treatment with chemoradiation (HR, 1.32; 95 % CI, 0.91-1.93, p = 0.14) or lack of vascularized tissue reconstruction (HR, 1.41, 95 % CI 0.91-2.18, p = 0.12). Significant association between PCF and advanced stage (T3 or T4), positive margin, close margin (<5mm), lymphovascular invasion and pre-operative tracheostomy were identified on univariable analysis. Positive surgical margin (HR, 1.91; 95 % CI, 1.11 to 3.29) was the only significant association on multivariable analysis. CONCLUSION: We highlight positive surgical margin as the only variable significantly associated with increased risk of PCF following salvage TL on multivariable analysis in a large cohort across several major head and neck oncology centers.

Parametric Multi-Scale Modeling of the Zygomaticus Major and Minor: Implications for Facial Reanimation.

ABSTRACT: Facial paralysis can severely impact functionality and mental health. Facial reanimation surgery can improve facial symmetry and movement. Zygomaticus minor (Zmin) and zygomaticus major (Zmaj) are 2 important perioral muscles, that function to elevate the upper lip, contributing to the formation of a smile. The objective of this study was to analyze the morphology in three-dimensional (3D) and quantify architectural parameters of Zmin and Zmaj. In ten formalin-embalmed specimens, Zmin and Zmaj were serially dissected and digitized at the fiber bundle level. The 2 muscles were modeled in 3D to construct high fidelity models. The 3D models were used to assess muscle morphology and quantify architectural parameters including mean fiber bundle length, physiological cross-sectional area, and line of action. Zygomaticus minor fiber bundles were oriented horizontally or slightly obliquely and had a muscular attachment to the medial modiolus. Zygomaticus minor was found to either have no partitions or medial and lateral partitions. Specimens with partitions were divided into type 1 and type 2. Type 1 consisted of a medial partition with fiber bundles attaching to the zygomatic bone at the inferior margin of the orbit. The type 2 medial partition attached to the lateral margin of the orbit to attach to the zygomatic bone. Zygomaticus major had obliquely oriented fiber bundles with most specimens having inferior and superior partitions attaching to the inferior aspect of the zygomatic bone. Zygomaticus major was found to have a greater mean fiber bundle length and physiological cross-sectional area than Zmin. The direction of the line of action of Zmin and Zmaj was closely related to fiber bundle arrangement. Detailed 3D anatomical understanding of Zmin and Zmaj, at the fiber bundle level, is critical for reconstructive surgeons performing dynamic facial reanimation. This data can be used to assist with selecting the ideal donor site for reconstruction.

Association of Plate Contouring With Hardware Complications Following Mandibular Reconstruction.

OBJECTIVES/HYPOTHESIS: Despite considerable effort being dedicated to contouring reconstruction plates, there remains limited evidence demonstrating an association between contour and reconstructive outcomes. We sought to evaluate whether optimizing mandibular reconstruction plate contouring is associated with reduced postoperative hardware complications. STUDY DESIGN: Retrospective cohort study. METHODS: A cohort study was performed with adult patients (age ≥18 years) who underwent mandibulectomy and osseous free flap reconstruction following oncologic ablation at the University Health Network in Toronto, Canada, between January 1, 2003 and December 31, 2014. Patients with computed tomography scans performed within 1 year of reconstruction were included. Computer-based three-dimensional models were generated and used to calculate the mean plate-to-bone gap (mm). The primary outcome was plate exposure. Secondary outcome included a composite of plate exposure or intraoral dehiscence. Logistic regression models were fitted for each outcome accounting for other patient and surgical characteristics associated with the primary outcome. RESULTS: Ninety-four patients met inclusion criteria, with a mean age of 60.4 (standard deviation [SD] 14.9). The mean follow-up time was 31.4 months (range 3-94). Reconstruction was performed with fibular (57%) and scapular free flaps (43%). In the multivariable model, small mean plate-to-bone gap (<1 mm) was independently associated with 86% reduced odds of plate exposure (odds ratio [OR] 0.12; 95% confidence interval [CI] 0.02-0.55). Mean plate-to-bone gap less than 1 mm was also independently associated with reduced odds of developing a composite of plate exposure or intraoral dehiscence (OR, 0.29; 95%CI, 0.11-0.75). CONCLUSION: Optimizing plate contouring during mandibular reconstruction may decrease the development of postoperative hardware complications. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:61-66, 2022.

Applications of intraoperative angiography in head and neck reconstruction.

OBJECTIVE: Laser-assisted angiography with indocyanine green (LAIG) allows objective intraoperative evaluation of tissue vascularity. We endeavored to describe our experience with this technique in the head and neck region. METHODS: A retrospective review from February 2016 till October 2018 was conducted. We included patients who underwent head and neck procedures in which LAIG was employed. The main outcome was postoperative wound complications. We analysed the influence of LAIG results in intraoperative decision-making process. RESULTS: Nineteen patients were included, and follow-up was for at least 6 months. LAIG was employed in 11 local flaps, 9 free flaps and 6 cases of pharyngeal closure during total laryngectomies. Wound complications occurred in two cases with distal tip flap necrosis. LAIG findings resulted in changes in decision making intraoperatively in 84% of procedures, which consisted in trimming poorly perfused tissues. There were no pharyngocutaneous fistulas. CONCLUSIONS: This represents a descriptive report on the use of LAIG on diverse head and neck reconstruction cases, with important impact on the decision-making process. A low number of postoperative wound complications were observed.

Association of Pharyngocutaneous Fistula With Cancer Outcomes in Patients After Laryngectomy: A Multicenter Collaborative Cohort Study.

Importance: Pharyngocutaneous fistula (PCF) results in an inflammatory reaction, but its association with the rate of locoregional and distant control, disease-free survival, and overall survival in laryngeal cancer remains uncertain. Objective: To determine if pharyngocutaneous fistula after salvage laryngectomy is associated with locoregional and distant control, disease-free survival, and/or overall survival. Design, Setting, and Participants: A multicenter collaborative retrospective cohort study conducted at 5 centers in Canada and the US of 550 patients who underwent salvage laryngectomy for recurrent laryngeal cancer from January 1, 2000, to December 31, 2014. The median follow-up time was 5.7 years (range, 0-18 years). Main Outcomes and Measures: Outcomes examined included locoregional and distant control, disease-free survival, and overall survival. Fine and Gray competing risk regression and Cox-proportional hazard regression models were used for outcomes. Competing risks and the Kaplan-Meier methods were used to estimate outcomes at 3 years and 5 years. Results: In all, 550 patients (mean [SD] age, 64 [10.4] years; men, 465 [85%]) met inclusion criteria. Pharyngocutaneous fistula occurred in 127 patients (23%). The difference in locoregional control between the group of patients with PCF (75%) and the non-PCF (72%) group was 3% (95% CI, -6% to 12%). The difference in overall survival between the group with PCF (44%) and the non-PCF group (52%) was 8% (95% CI, -2% to 20%). The difference in disease-free survival between PCF and non-PCF groups was 6% (95% CI, -4% to 16%). In the multivariable model, patients with PCF were at a 2-fold higher rate of distant metastases (hazard ratio, 2.00; 95% CI, 1.22 to 3.27). Distant control was reduced in those with PCF, a 13% (95% CI, 3% to 21%) difference in 5-year distant control. Conclusions and Relevance: This multicenter retrospective cohort study found that development of PCF after salvage laryngectomy is associated with an increased risk for the development of distant metastases.

Perioperative Mortality Risk in Patients Undergoing Transoral Robotic Surgery for T1-T2 Oropharyngeal Squamous Cell Carcinoma: A National Cancer Database Study.

The National Cancer Database is a joint project of the Commission on Cancer of the American College of Surgeons and the American Cancer Society. The American College of Surgeons and the Commission on Cancer have not verified and are not responsible for the analytic or statistical methods used or for the conclusions drawn from these data by the investigators. INTRODUCTION: Transoral robotic surgery (TORS) is well established as initial definitive treatment for early-stage oropharyngeal squamous cell carcinoma (OPSCC) as an alternative to radiation therapy with similar survival rates. While proponents of TORS focus on the reduced morbidity of treatment compared to open procedures, shortened hospital admissions and equivalent survival outcomes to non-surgical treatment, there remain concerns over the risk of mortality within the acute perioperative period. Therefore, we sought to determine the 30-day and 90-day perioperative mortality risk using the National Cancer Database. METHODS: A retrospective cohort analysis was performed for patients diagnosed with pathologic T1/2 OPSCC between January 1, 2010, and December 31, 2016 that underwent primary surgical treatment with TORS and was not restricted by HPV status. The primary outcome was 30-day perioperative mortality. The secondary outcome was 90-day perioperative mortality. Univariable analysis was used to identify variables associated with 30-day perioperative mortality. RESULTS: In total, 4,127 patients (mean [SD; range] age, 59 [9.5; 22-90] years; 3,476 [84%] men and 651 [16%] women) met inclusion criteria. The number of patients with pT1-2 OPSCC undergoing TORS increased three-fold between 2010 (279/4,127; 7%) to 2016 (852/4,127; 21%). The overall 30-day and 90-day perioperative mortality rate for TORS during the study period was 0.6% (23/4,127) and 0.9% (38/4,127), respectively. On univariable analysis (UVA), age≥65 was the only predictor of 30-day perioperative mortality (OR 3.41; 95% CI 1.49-7.81). CONCLUSION: The overall risk of all cause mortality following TORS for early-stage OPSCC remains low. The risk of mortality is higher in elderly patients and should be considered, in addition to previously established risk factors, during patient selection and counselling.

Establishing Orbital Floor Symmetry to Support Mirror Imaging in Computer-Aided Reconstruction of the Orbital Floor.

BACKGROUND: Surgical precision in the reconstruction of the orbital floor is crucial to functional visual and aesthetic outcomes. Increasingly, computer-aided design is being utilized to aid in precise preoperative planning by using the mirror images of the unaffected side. The authors aim to use 3-dimensional (3D) quantitative analysis to establish whether the native orbital floor topography is sufficiently symmetric to support this practice. METHODS: Ten high resolution head and neck computed tomography scans of patients without periorbital pathology were obtained. These were imported into a 3D medical image processing software and segmented to isolate bilateral orbital floors. Each native orbital floor was compared to the mirror image of the contralateral side by conformance map computation. Data collection included measures of 25% and 75% quartile, median, mean, standard deviation, and root-mean-square (RMS). RESULTS: The topographic analysis demonstrated a high degree of topographic conformance with a mean RMS of 0.58 ±â€Š0.37 mm. Further volumetric analysis comparing the total orbital volume between each side also demonstrates a high degree of volumetric symmetry with a mean difference of 0.55 mL (P = 0.30). CONCLUSION: Comparison of the native orbital floor and the mirror image of the contralateral side by conformance map computation and volumetric analysis demonstrated a high degree of morphologic similarity. The native orbital floor topography provides optimal symmetry to support mirror imaging techniques used in orbital floor reconstruction.