A deployable curriculum with 3D printed skills trainers for altered airway management.

BACKGROUND: Altered Airway Anatomy (AAA), including tracheostomies and laryngectomies, may represent an area of unease for non-Otolaryngology trainees, due to a lack of exposure, structured education, or dedicated training in altered airway management. Inability to effectively stabilize an altered airway is associated with significant risk of patient morbidity and mortality. This study aims to assess the efficacy of a concise curriculum using three-dimensional (3D) printed airway models for skill training in improving Anesthesiology trainees' competency in AAA management. METHODS: A prospective cohort of 42 anesthesiology residents at a tertiary care institution were guided through a 75-min curriculum on AAA, including case discussion, surgical video, and hands-on practice with tracheostomy and laryngectomy skills trainers. Pre- and post- course surveys assessing provider confidence (Likert scale) and knowledge (multiple choice questions) were administered. Additionally, an observed skills competency assessment was performed. RESULTS: Self-perceived confidence improved from a summative score across all domains of 23.65/40 pre-course to 36.39/40 post-course (n = 31, p < 0.001). Technical knowledge on multiple choice questions improved from 71 to 95% (n = 29, p < 0.001). In the completed skills competency assessment, 42/42 residents completed 5/5 assessed tasks successfully, demonstrating objective skills-based competency. CONCLUSIONS: This study demonstrates an improvement in anesthesiology resident self-assessed confidence, objective knowledge, and skills based competency surrounding management of patients with AAA following a 75-min simulation-based curriculum.

Higher Computed Tomography (CT) Scan Resolution Improves Accuracy of Patient-specific Mandibular Models When Compared to Cadaveric Gold Standard.

BACKGROUND: 3D-printed patient-specific anatomical models are becoming an increasingly popular tool for planning reconstructive surgeries to treat oral cancer. Currently there is a lack of information regarding model accuracy, and how the resolution of the computed tomography (CT) scan affects the accuracy of the final model. PURPOSE: The primary objective of this study was to determine the CT z-axis resolution necessary in creating a patient specific mandibular model with clinically acceptable accuracy for global bony reconstruction. This study also sought to evaluate the effect of the digital sculpting and 3D printing process on model accuracy. STUDY DESIGN: This was a cross-sectional study using cadaveric heads obtained from the Ohio State University Body Donation Program. INDEPENDENT VARIABLES: The first independent variable is CT scan slice thickness of either 0.675 , 1.25, 3.00, or 5.00 mm. The second independent variable is the three produced models for analysis (unsculpted, digitally sculpted, 3D printed). MAIN OUTCOME VARIABLE: The degree of accuracy of a model as defined by the root mean square (RMS) value, a measure of a model's discrepancy from its respective cadaveric anatomy. ANALYSES: All models were digitally compared to their cadaveric bony anatomy using a metrology surface scan of the dissected mandible. The RMS value of each comparison evaluates the level of discrepancy. One-way ANOVA tests (P < .05) were used to determine statistically significant differences between CT scan resolutions. Two-way ANOVA tests (P < .05) were used to determine statistically significant differences between groups. RESULTS: CT scans acquired for 8 formalin-fixed cadaver heads were processed and analyzed. The RMS for digitally sculpted models decreased as slice thickness decreased, confirming that higher resolution CT scans resulted in statistically more accurate model production when compared to the cadaveric gold standard. Furthermore, digitally sculpted models were significantly more accurate than unsculpted models (P < .05) at each slice thickness. CONCLUSIONS: Our study demonstrated that CT scans with slice thicknesses of 3.00 mm or smaller created statistically significantly more accurate models than models created from slice thicknesses of 5.00 mm. The digital sculpting process statistically significantly increased the accuracy of models and no loss of accuracy through the 3D printing process was observed.

Tissue Engineering: Current Technology for Facial Reconstruction.

Facial reconstruction is a complex surgical process that requires intricate three-dimensional (3D) concepts for optimal functional and aesthetic outcomes. Conventional reconstruction of structural facial anomalies, such as those including cartilage or bony defects, typically rely on hand-carving autologous constructs harvested from a separate donor site, and shaping that cartilage or bone into a new structural framework. Tissue engineering has emerged in recent decades as a potential approach to mitigate the need for donor site morbidity while improving precision in the design of reconstructive construct. Computer-aided design and computer-aided manufacturing have allowed for a digital 3D workflow to digitally execute the planned reconstruction in virtual space. 3D printing and other manufacturing techniques can then be utilized to create custom-fabricated scaffolds and guides to improve the reconstructive efficiency. Tissue engineering can be paired with custom 3D-manufactured scaffolds to theoretically create an ideal framework for structural reconstruction. In the past decade, there have been several compelling preclinical studies demonstrating the capacity to induce chondrogenesis or osteogenesis in a custom scaffold. However, to date, these preclinical data have not yet translated into significant clinical experience. This translation has been hindered by a lack of consensus on the ideal materials and cellular progenitors to be utilized in these constructs and a lack of regulatory guidance and control to enable clinical application. In this review, we highlight the current state of tissue engineering in facial reconstruction and exciting potential for future applications as the field continues to advance.

Stage Migration and Survival Trends in Laryngeal Cancer.

BACKGROUND: During the last two decades, significant advancements in the treatment of laryngeal cancer have occurred. Although survival of head and neck cancer patients has improved over time, the temporal trend of laryngeal cancer survival is an area of controversy. METHODS: From 2004 to 2016, 77,527 patients who had laryngeal cancer treated with curative intent in the United States were identified in the National Cancer Database. Relative and observed survival rates were assessed for temporal trends. Multinomial logistic regression investigated the relationship between American Joint Committee on Cancer (AJCC) stage and increasing calendar year. RESULTS: No significant improvement in 2- or 5-year observed survival (OS) or relative survival (RS) was observed. The 5-year RS ranged from 61.72 to 63.97%, and the 5-year OS ranged from 54.26 to 56.52%. With each increasing year, the proportion of stage 4 disease increased, with risk for stage 4 disease at the time of diagnosis increasing 2.2% annually (adjusted odds ratio [aOR], 1.022; 95% confidence interval [CI], 1.017-1.028; p < 0.001). This increase was driven by a 4.7% yearly increase in N2 disease (aOR, 1.047; 95% CI, 1.041-1.053; p < 0.001), with an annual 1.2% increase in T3 disease (aOR, 1.012; 95% CI, 1.007-1.018; p < 0.001) and a 1.2% increase in T4 disease (aOR, 1.012; 95% CI, 1.005-1.018; p < 0.001). CONCLUSION: Despite advances in the field, laryngeal cancer survival in the United States is not improving over time. This may be due to an increase in the proportion of stage 4 disease, driven primarily by increasing nodal disease. To achieve survival improvement commensurate with scientific and technologic advances, efforts should be made to diagnose and treat laryngeal cancer at earlier stages to prevent further stage migration.

Establishing a point-of-care additive manufacturing workflow for clinical use.

Additive manufacturing, or 3-Dimensional (3-D) Printing, is built with technology that utilizes layering techniques to build 3-D structures. Today, its use in medicine includes tissue and organ engineering, creation of prosthetics, the manufacturing of anatomical models for preoperative planning, education with high-fidelity simulations, and the production of surgical guides. Traditionally, these 3-D prints have been manufactured by commercial vendors. However, there are various limitations in the adaptability of these vendors to program-specific needs. Therefore, the implementation of a point-of-care in-house 3-D modeling and printing workflow that allows for customization of 3-D model production is desired. In this manuscript, we detail the process of additive manufacturing within the scope of medicine, focusing on the individual components to create a centralized in-house point-of-care manufacturing workflow. Finally, we highlight a myriad of clinical examples to demonstrate the impact that additive manufacturing brings to the field of medicine.

An In-House Computer-Aided Design and Computer-Aided Manufacturing Workflow for Maxillofacial Free Flap Reconstruction is Associated With a Low Cost and High Accuracy.

PURPOSE: In-house computer-aided surgical design and computer-aided manufacturing (CAD/CAM) can be used in oral and maxillofacial surgery for virtual surgical planning and 3-dimensional printing of patient-specific models. The purpose of this study was to measure the cost and accuracy of an in-house CAD/CAM workflow for maxillofacial free flap reconstruction. MATERIALS AND METHODS: A retrospective cohort study of patients undergoing mandibular resection and free flap reconstruction was performed between July 2017 and March 2018 in which in-house CAD/CAM was used. The predictor variable was the in-house CAD/CAM workflow. The outcome variables were in-house workflow cost, as measured by the material expenses, and accuracy, as measured by comparative distance, osteotomy angle, and surfaced overlay measurements and the root mean square (RMS) between the preoperative virtual reconstructive plan and the postoperative computed tomography scan. Additional variables evaluated were time required for in-house CAD/CAM workflow, and clinical and radiographic outcomes. RESULTS: In-house CAD/CAM was used for 26 patients undergoing mandibular resection for benign or malignant disease and free flap reconstruction with fibula (n = 24) or scapula free flap (n = 2). Overall flap success rate was 95%. The mean in-house workflow cost per case was $3.87 USD. There were no significant differences between the mean comparative distance and osteotomy angle measurements between the planned and actual mandibular reconstructions with an RMS ranging from 5.11 to 9.00 mm for distance measurements and 17.41° for the osteotomy angle measurements. The mean surface overlay difference was 1.90 mm with an RMS of 3.72 mm. CONCLUSIONS: The in-house CAD/CAM workflow is a low cost and accurate option for maxillofacial free flap reconstruction. The in-house workflow should be considered as an alternative to current practices using proprietary systems in select cases.

Management of the positive sentinel lymph node in the post-MSLT-II era.

BACKGROUND AND OBJECTIVES: The publication of MSLT-II shifted recommendations for management of sentinel lymph node biopsy positive (SLNB+) melanoma to favor active surveillance. We examined trends in immediate completion lymph node dissection (CLND) following publication of MSLT-II. METHODS: Using a prospective melanoma database at a high-volume center, we identified a cohort of consecutive SLNB+ patients from July 2016 to April 2019. Patient and disease characteristics were analyzed with multivariate logistic regression to examine factors associated with CLND. RESULTS: Two hundred and thirty-five patients were included for analysis. CLND rates were 67%, 33%, and 26% for the year before, year after, and second-year following MSLT-II. Factors associated with undergoing CLND included primary located in the head and neck (59% vs 33%, P = .003 and odds ratio [OR], 5.22, P = .002) and higher sentinel node tumor burden (43% vs 10% for tumor burden ≥0.1 mm, P < .001 and OR, 8.64, P = .002). CONCLUSIONS: Rates of CLND in SLNB+ melanoma decreased dramatically, albeit not uniformly, following MSLT-II. Factors that increased the likelihood of immediate CLND were primary tumor located in the head and neck and high sentinel node tumor burden. These groups were underrepresented in MSLT-II, suggesting that clinicians are wary of implementing active surveillance recommendations for patients perceived as higher risk.

Elective Paratracheal Lymph Node Dissection in Salvage Laryngectomy.

BACKGROUND: Indications for and efficacy of paratracheal nodal dissection (PTND) in patients undergoing laryngectomy (salvage) for persistent or recurrent laryngeal squamous cell carcinoma are not well-defined. METHODS: A retrospective cohort study was performed for patients undergoing salvage laryngectomy with clinically and radiographically negative neck disease between 1998 and 2015 (n = 210). Univariate and multivariate Cox regression analyses were performed. RESULTS: PTND was performed on 77/210 patients (36%). The PTND cohort had a greater proportion of advanced T classification (rT3/rT4) tumors (78%) than subjects without PTND (55%; p = 0.001). There was a 14% rate of occult nodal metastases in the paratracheal basin; of these, 55% did not have pathologic lateral neck disease. Multivariate analysis controlling for tumor site, tumor stage, and pathologic lateral neck disease demonstrated that PTND was associated with improved overall survival [OS] (p = 0.03; hazard ratio [HR] 0.60, 95% confidence interval [CI] 0.38-0.96), disease-free survival [DFS] (p = 0.03; HR 0.55, 95% CI 0.31-0.96), and distant DFS survival (p = 0.01; HR 0.29, 95% CI 0.11-0.77). The rate of hypocalcemia did not differ between subjects who underwent bilateral PTND, unilateral PTND, or no PTND (p = 0.19 at discharge, p = 0.17 at last follow-up). CONCLUSIONS: PTND at the time of salvage laryngectomy was more common in patients with rT3/rT4 tumors and was associated with improved OS and DFS, with no effect on hypocalcemia. In patients undergoing PTND, the finding of occult paratracheal metastases was often independent of lateral neck metastases.

Management of frontoethmoidal osteoma causing pneumocephalus and cerebrospinal fluid leakage with minimally invasive techniques: illustrative cases.

BACKGROUND: Osteoid osteoma is a common benign bone tumor frequently seen in the frontoethmoid region. However, involvement of the skull base is rare, with few cases previously reported. OBSERVATIONS: The authors report two cases of spontaneous, symptomatic frontoethmoidal osteoma: one presented with neurological deficit secondary to tension pneumocephalus and the other with cerebrospinal fluid leakage. The first case was managed with a transfrontal sinus craniotomy and pneumocephalus decompression with osteoma resection and skull base reconstruction. The second case was managed with a uninaral endoscopic endonasal approach to the anterior skull base with osteoma resection and reconstruction. LESSONS: Given the paucity of cases with associated tension pneumocephalus described in the literature, it was relevant to describe the authors' experience with surgical decision-making and the expected outcomes among patients with this pathology when using minimally invasive techniques.

SMARCB1-Deficient Skull Base Chondrosarcoma with 12p Duplication Presenting as Somatic-Type Malignancy Arising from Metastatic Seminoma.

Somatic-type malignancy (STM) can occur infrequently within a primary or metastatic testicular germ cell tumor (TGCT) and is associated with dismal prognosis and survival. STM with chondrosarcomatous features is exceedingly rare and head and neck involvement has not been previously documented. A 39-year-old white man presented with nasal obstruction and epistaxis. Imaging disclosed a 6.9-cm expansile tumor involving the nasal cavity and skull base with intraorbital and intracranial extension. The histopathologic properties of the tumor were compatible with chondrosarcoma, grade II-III. Immunohistochemically, malignant cells were strongly and diffusely positive for S100 and epithelial markers, and showed loss of SMARCB1 expression. IDH1/2 mutations were not detected. Following whole-body PET scan, a 7.0-cm left testicular mass was discovered and diagnosed as seminoma with syncytiotrophoblastic cells, stage pT3NXM1b. Extensive retroperitoneal, mediastinal, and supraclavicular lymphadenopathy was also noticed. Histopathologic examination of the left supraclavicular lymph node revealed metastatic seminoma. By FISH, most metastatic nodal seminoma cells harbored 1 to 4 copies of isochromosome 12p, while the chondrosarcoma featured duplication of 12p. Presence of a malignant TGCT with disseminated supradiaphragmatic lymphadenopathy, the unique immunophenotypic properties of the skull-based chondrosarcoma and lack of IDH1/2 aberrations with gain of 12p strongly support the diagnosis of STM chondrosarcoma arising from metastatic TGCT. The patient did not respond to chemotherapy and succumbed three months after diagnosis. Although exceedingly uncommon, metastasis to the head and neck may occur in patients with TGCT. This case of STM chondrosarcoma demonstrated divergent immunophenotypic and molecular characteristics compared to "typical" examples of head and neck chondrosarcoma. High index of suspicion is advised regarding the diagnosis of lesions that present with otherwise typical histomorphology but unexpected immunohistochemical or molecular features.

Ablation of Focal Atrial Tachycardia from a Large Left Atrial Diverticulum Using 3D Printing.

We present a case of a 45-year-old male with symptomatic supraventricular tachycardia. Electrophysiology study and 3-dimensional (3D) electroanatomic mapping showed a focal atrial tachycardia originating from a large left atrial diverticulum. Due to the unusual anatomy, 3D printing models were used to aid successful catheter ablation of the atrial tachycardia.

A Pilot Study: Free Flap Atrophy in Tongue Reconstruction Using 3D Volumetric Analysis.

OBJECTIVE: To identify factors influencing volume change in non-osseous oral free flap reconstruction using postoperative cross-sectional imaging and 3-dimensional segmentation of the free flap's muscular and adipose tissue content. METHODS: Oral tongue free flap reconstruction cases (2014-2019) were reviewed with inclusion of patients with 3 postoperative, cross-sectional imaging studies with 1 within 6 months, 1 within 1 year, and 1 that spanned 2 years post-reconstruction. Exclusion criteria included recurrence, significant dental artifact, bony reconstruction, and flap failure. Demographics, risk factors, and surgical/clinical treatments were identified. Flap volumes were measured using Materialise MIMICS. RESULTS: Twenty-two patients met strict inclusion criteria. Four flaps were anterolateral thighs and 18 radial forearms. Median percent volume loss greater than 2 years post-reconstruction was 53.2% overall, 58.1% for radial forearms, and 45.4% for ALTs (21.4% for adipose tissue and 57.4% for muscular tissue). Univariate analysis revealed glossectomy amount was associated with percent volume loss (P = .0417). Each successive postoperative month, the flap decreased by 1.54% (P < .0001). Checking for the interaction effect, the percent of flap loss across time was different for glossectomy amount (P = .0093), obesity status (P = .0431), and base of tongue involvement (P = .0472). CONCLUSION: Glossectomy type, and thus flap size, is a positive predictor for flap atrophy. Obesity and base of tongue involvement are negative predictors for flap atrophy. The amount of tissue loss may differ from classical teachings with median atrophy 53.2% greater than 2 years post-reconstruction.

Exploring CT pixel and voxel size effect on anatomic modeling in mandibular reconstruction.

BACKGROUND: Computer-aided modeling and design (CAM/CAD) of patient anatomy from computed tomography (CT) imaging and 3D printing technology enable the creation of tangible, patient-specific anatomic models that can be used for surgical guidance. These models have been associated with better patient outcomes; however, a lack of CT imaging guidelines risks the capture of unsuitable imaging for patient-specific modeling. This study aims to investigate how CT image pixel size (X-Y) and slice thickness (Z) impact the accuracy of mandibular models. METHODS: Six cadaver heads were CT scanned at varying slice thicknesses and pixel sizes and turned into CAD models of the mandible for each scan. The cadaveric mandibles were then dissected and surface scanned, producing a CAD model of the true anatomy to be used as the gold standard for digital comparison. The root mean square (RMS) value of these comparisons, and the percentage of points that deviated from the true cadaveric anatomy by over 2.00 mm were used to evaluate accuracy. Two-way ANOVA and Tukey-Kramer post-hoc tests were used to determine significant differences in accuracy. RESULTS: Two-way ANOVA demonstrated significant difference in RMS for slice thickness but not pixel size while post-hoc testing showed a significant difference in pixel size only between pixels of 0.32 mm and 1.32 mm. For slice thickness, post-hoc testing revealed significantly smaller RMS values for scans with slice thicknesses of 0.67 mm, 1.25 mm, and 3.00 mm compared to those with a slice thickness of 5.00 mm. No significant differences were found between 0.67 mm, 1.25 mm, and 3.00 mm slice thicknesses. Results for the percentage of points deviating from cadaveric anatomy greater than 2.00 mm agreed with those for RMS except when comparing pixel sizes of 0.75 mm and 0.818 mm against 1.32 mm in post-hoc testing, which showed a significant difference as well. CONCLUSION: This study suggests that slice thickness has a more significant impact on 3D model accuracy than pixel size, providing objective validation for guidelines favoring rigorous standards for slice thickness while recommending isotropic voxels. Additionally, our results indicate that CT scans up to 3.00 mm in slice thickness may provide an adequate 3D model for facial bony anatomy, such as the mandible, depending on the clinical indication.

Endoscopic endonasal approach for resection of sellar leiomyosarcoma metastasis: illustrative case.

BACKGROUND: Leiomyosarcoma (LMS) is a rare neoplasm that arises from tissues of embryonic mesodermal origin. Primary tissues of origin can include smooth muscle cells of the abdominopelvic viscera, blood vessels, or arrector pili muscles. LMS is known to metastasize to the lungs, with few reported cases of spread to the central nervous system. OBSERVATIONS: A 66-year-old male with cutaneous LMS of the left forearm with metastases to the lungs and kidney that had been treated with chemoradiation presented with worsening headaches. Magnetic resonance imaging revealed a sellar lesion. An endocrine workup was unremarkable. Imaging over 6 months revealed rapid interval growth. Positron emission tomography demonstrated moderate uptake. Given the rapid growth, the patient was offered an endoscopic endonasal approach for resection. Pathology confirmed LMS. LESSONS: To the authors' knowledge, this is the first documented case of LMS metastasis to the sella. Pituitary carcinoma or metastases to the sellar region should be in the differential among patients with sellar region tumors with a rapid growth rate, bony erosion, or findings of lesions in the upper cervical lymph nodes or soft tissue. Tumors that show significant interval growth should raise suspicion for nonadenomatous lesions, and surgical intervention should be considered even in the absence of endocrinological dysfunction or cranial neuropathies. https://thejns.org/doi/10.3171/CASE2435.

Advantages and caveats of endoscopic to the infratemporal fossa as isolated and combined techniques.

Objective: Identify the benefits and caveats of combining minimal access approaches to the infratemporal fossa (ITF), such as the endoscopic transnasal, endoscopic transorbital, endoscopic transoral, and endoscopic sublabial transmaxillary approaches to address extensive lesions not amenable to a single approach. The study provides anatomical metrics including area of exposure and degree of surgical freedom. Methods: Five human cadaveric specimens (10 sides) were dissected to expose and methodically analyze the anatomical intricacies of the ITF using the following minimal access approaches: endoscopic transnasal transpterygoid (EETA), endoscopic sublabial transmaxillary, endoscopic transorbital via infraorbital foramen, and endoscopic transoral techniques. Area of exposure at the pterygopalatine fossa and surgical freedom at the ITF were obtained for each approach. Results: The endoscopic sublabial transmaxillary sinus and the combined approach afford a significantly greater exposure than an isolated EETA. The difference in exposure (mean) between the endoscopic sublabial transmaxillary and EETA was 1.62 ± 0.85 cm2 (p < 0.001), and the difference between the combined approach and EETA was 4.25 ± 0.85 cm2 (p < 0.001). Conclusions: Combining minimal access endoscopic approaches to the ITF can provide significantly greater exposure than an isolated EETA; thus, providing enhanced access to address lesions with extensive involvement of the ITF, especially those with superolateral and inferolateral extensions. In addition, some approaches may have an adjunctive role to the resection, such as the endoscopic transoral approach offering the potential for early control of the internal maxillary artery and its branches, some of which may be supplying the tumor in the ITF; or the endoscopic transorbital approach yielding a direct line of sight to the superior ITF and middle cranial fossa. Level of Evidence: NA.

Dynamic flow for efficient partial decellularization of tracheal grafts: A preliminary rabbit study.

Objective: Bioengineered tracheal grafts are a potential solution for the repair of long-segment tracheal defects. A recent advancement is partially decellularized tracheal grafts (PDTGs) which enable regeneration of host epithelium and retain viable donor chondrocytes for hypothesized benefits to mechanical properties. We propose a novel and tunable 3D-printed bioreactor for creating large animal PDTG that brings this technology closer to the bedside. Methods: Conventional agitated immersion with surfactant and enzymatic activity was used to partially decellularize New Zealand white rabbit (Oryctolagus cuniculus) tracheal segments (n = 3). In parallel, tracheal segments (n = 3) were decellularized in the bioreactor with continuous extraluminal flow of medium and alternating intraluminal flow of surfactant and medium. Unprocessed tracheal segments (n = 3) were also collected as a control. The grafts were assessed using the H&E stain, tissue DNA content, live/dead assay, Masson's trichrome stain, and mechanical testing. Results: Conventional processing required 10 h to achieve decellularization of the epithelium and submucosa with poor chondrocyte viability and mechanical strength. Using the bioreactor reduced processing time by 6 h and resulted in chondrocyte viability and mechanical strength similar to that of native trachea. Conclusion: Large animal PDTG created using our novel 3D printed bioreactor is a promising approach to efficiently produce tracheal grafts. The bioreactor offers flexibility and adjustability favorable to creating PDTG for clinical research and use. Future research includes optimizing flow conditions and transplantation to assess post-implant regeneration and mechanical properties. Level of Evidence: NA.

Contralateral Nasofrontal Trephination: A Novel Corridor for a "Dual Port" Approach to the Petrous Apex.

BACKGROUND AND OBJECTIVES: Expanded endonasal approaches (EEAs) have proven safe and effective in treating select petrous apex (PA) pathologies. Angled endoscopes and instruments have expanded indications for such approaches; however, the complex neurovascular anatomy surrounding the petrous region remains a significant challenge. This study evaluates the feasibility, anatomic aspects, and limitations of a contralateral nasofrontal trephination (CNT) route as a complementary corridor improving access to the PA. METHODS: Expanded endonasal and CNT approaches to the PA were carried out bilaterally in 15 cadaveric heads with endovascular latex injections. The distance to the PA, angle between instruments through the 2 approach portals, and surgical freedom were measured and compared. RESULTS: Three-dimensional DICOM-based modeling and visualization indicate that the CNT route reduces the distance to the target located within the contralateral PA by an average of 3.33 cm (19%) and affords a significant increase in the angle between instruments (15.60°; 54%). Furthermore, the vertical vector of approach is improved by 28.97° yielding a caudal reach advantage of 2 cm. The area of surgical freedom afforded by 3 different approaches (endonasal, endonasal with an endoscope in CNT portal, and endonasal with an instrument in CNT portal) was compared at 4 points: the dural exit point of the 6th cranial nerve, jugular foramen, foramen lacerum, and petroclival fissure. The mean area of surgical freedom provided by both approaches incorporating the CNT corridor was superior to EEA alone at each of the surgical targets ( P = <.001). CONCLUSION: The addition of a CNT portal provides an additional avenue to expand on the classical EEA to the PA. This study provides insight into the anatomic nuances and potential clinical benefits of a dual-port approach to the PA.

Effectiveness of Nasolacrimal SCC Treatments and Promising Role of Chemo-Induction: A Case Report and Systematic Review.

OBJECTIVE: To comprehensively analyze reported cases of nasolacrimal squamous cell carcinoma (NLSCC), focusing on risk factors, treatment modalities, and outcomes. Additionally, investigate the impact of human Papillomavirus (HPV) status and histopathological subtypes' impact on prognosis. DATA SOURCES: Pubmed, Embase. REVIEW METHODS: We conducted a systematic literature review to identify relevant studies reporting cases of NLSCC. The review methods adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The final update was performed on May 31, 2023. RESULTS: The 72 studies included a total of 313 participants (mean age: 55; 60% male). Longer symptom duration (44.1 ± 59.2 months) correlated with recurrence (p = 0.004), and males exhibited higher mortality rates (19.6% vs. 2.4% in females, p = 0.01). The overall survival (OS) rate among all patients was 87.1%. Basaloid NLSCC had a worse death outcome (p ≤ 0.001). HPV-positive cases showed comparable OS, recurrence, and metastasis rates to the general population (p = 0.917, 0.851, 0.07, respectively). Comparing treatment approaches (surgery, surgery with adjuvant radiation, chemoradiotherapy [CRT] followed by surgery), no significant differences in 5 and 10-year OS rates or recurrence were observed (p = 0.4, 0.24, respectively), but 5-year metastasis events were significant (p = 0.024). Eye exenteration rates were 31.1%, 20%, and 0% for the respective treatments (p = 0.089). Induction chemotherapy saved four cases from potential exenteration with favorable prognosis. CONCLUSION: Early detection and diagnosis are of utmost importance in the management of NLSCC. Regardless of the treatment approach, HPV-related NLSCC demonstrated similar outcomes to the general population. Basaloid histology represents the worst subtype in terms of prognosis. Limited adjuvant CRT cases showed improved outcomes and induction chemotherapy's importance was emphasized in recent literature and our shared experience. Laryngoscope, 134:3892-3902, 2024.

3D modeling of anterior 2/3rds glossectomy reconstruction: A volume based donor site evaluation.

OBJECTIVE: Anterior 2/3rds glossectomy results in significant patient morbidity due to speech and swallowing impairment. Microvascular free flap reconstruction compensates for large volume defects. Flap volume is based on the adipose content of the donor site and varies by patient body mass index (BMI) and donor site location. We sought to correlate flap thickness at different donor sites with patient BMI to determine optimal donor site selection. METHODS: Patients with CT scans of the oral cavity, thorax and lower extremity were identified and included. The volumes of the anterior 2/3rds of the tongue were measured and recorded using computed tomography-generated modeling. Pre-muscular tissue thicknesses at anterolateral thigh (ALT), deep inferior epigastric artery (DIEP), latissimus dorsi, and parascapular donor sites were measured. The donor site adequency was defined as reconstructing the tongue volume within 10% of the ideal volume required and stratified based on patient BMI. RESULTS: In 144 patients, the average anterior 2/3rds glossectomy defect was 100.3 cm3. Glossectomy defect size was highly correlated with BMI (p < 0.001). The DIEP flap had the largest volume (155.4 cm3), followed by latissimus (105.6 cm3), parascapula (97.8 cm3), and ALT (60.5 cm3). For patients with BMI ≤ 30, the DIEP flap best reconstructed native tongue volume (up to 113 % of native tongue volume). In patients with BMI > 30.1, native tongue volumes were approximated by the latissimus flap (89-92 % of native tongue) and parascapular flap (85-95 % of native tongue volume). In BMI > 30.1 the DIEP flap provided excess tissue bulk (129-135 % of native tongue volume). CONCLUSION: The DIEP flap more closely approximates the volume needed to reconstruct anterior two-thirds tongue defects for BMIs ≤ 30. The subscapular system flaps provided the best volume match for BMIs > 30 and the DIEP flap provided excess tissue bulk which could be adjusted in the reconstruction process.