Upper airway reconstruction using long-range optical coherence tomography: Effects of airway curvature on airflow resistance.

OBJECTIVES: Adenotonsillectomy (AT) is commonly used to treat upper airway obstruction in children, but selection of patients who will benefit most from AT is challenging. The need for diagnostic evaluation tools without sedation, radiation, or high costs has motivated the development of long-range optical coherence tomography (LR-OCT), providing real-time cross-sectional airway imaging during endoscopy. Since the endoscope channel location is not tracked in conventional LR-OCT, airway curvature must be estimated and may affect predicted airway resistance. The study objective was to assess effects of three realistic airway curvatures on predicted airway resistance using computational fluid dynamics (CFD) in LR-OCT reconstructions of the upper airways of pediatric patients, before and after AT. METHODS: Eight subjects (five males, three females, aged 4-9 years) were imaged using LR-OCT before and after AT during sedated endoscopy. Three-dimensional (3D) airway reconstructions included three airway curvatures. Steady-state, inspiratory airflow simulations were conducted under laminar conditions, along with turbulent simulations for one subject using the k-ω turbulence model. Airway resistance (pressure drop/flow) was compared using two-tailed Wilcoxon signed rank tests. RESULTS: Regardless of the airway curvatures, CFD findings corroborate a surgical end-goal with computed post-operative airway resistance significantly less than pre-operative (P < 0.01). The individual resistances did not vary significantly for different airway curvatures (P > 0.25). Resistances computed using turbulent simulations differed from laminar results by less than ∼5%. CONCLUSIONS: The results suggest that reconstruction of the upper airways from LR-OCT imaging data may not need to account for airway curvature to be predictive of surgical effects on airway resistance. Lasers Surg. Med. 51:150-160, 2019. © 2018 Wiley Periodicals, Inc.

Effects of Mucosal Decongestion on Nasal Aerodynamics: A Pilot Study.

OBJECTIVE: Mucosal decongestion with nasal sprays is a common treatment for nasal airway obstruction. However, the impact of mucosal decongestion on nasal aerodynamics and the physiological mechanism of nasal airflow sensation are incompletely understood. The objective of this study is to compare nasal airflow patterns in nasal airway obstruction (NAO) patients with and without mucosal decongestion and nondecongested healthy subjects. STUDY DESIGN: Cross-sectional study of a convenience sample. SETTING: Academic tertiary medical center. METHODS: Forty-five subjects were studied (15 nondecongested healthy subjects, 15 nondecongested NAO patients, and 15 decongested NAO patients). Three-dimensional models of the nasal anatomy were created from computed tomography scans. Steady-state simulations of airflow and heat transfer were conducted at 15 L/min inhalation rate using computational fluid dynamics. RESULTS: In the narrow side of the nose, unilateral nasal resistance was similar in decongested NAO patients and nondecongested healthy subjects, but substantially higher in nondecongested NAO patients. The vertical airflow distribution within the nasal cavity (inferior vs middle vs superior) was also similar in decongested NAO patients and nondecongested healthy subjects, but nondecongested NAO patients had substantially less middle airflow. Mucosal cooling, quantified by the surface area where heat flux exceeds 50 W/m2, was significantly higher in decongested NAO patients than in nondecongested NAO patients. CONCLUSION: This pilot study suggests that mucosal decongestion improves objective measures of nasal airflow, which is consistent with improved subjective sensation of nasal patency after decongestion.

Estimation of Nasal Airway Cross-sectional Area From Endoscopy Using Depth Maps: A Proof-of-Concept Study.

OBJECTIVE: Endoscopy is routinely used to diagnose obstructive airway diseases. Currently, endoscopy is only a visualization technique and does not allow quantification of airspace cross-sectional areas (CSAs). This pilot study tested the hypothesis that CSAs can be accurately estimated from depth maps created from virtual endoscopy videos. STUDY DESIGN: Cross-sectional. SETTING: Academic tertiary medical center. METHODS: Virtual endoscopy and depth map videos of the nasal cavity were digitally created based on anatomically accurate three-dimensional (3D) models built from computed tomography scans of 30 subjects. A software tool was developed to outline the airway perimeter and estimate the airspace CSA from the depth maps. Two otolaryngologists used the software tool to estimate the nasopharynx CSA and the nasal valve minimal CSA (mCSA) in the left and right nasal cavities. Model validation statistics were performed. RESULTS: Nasopharynx CSA had a median percent error of 3.7% to 4.6% when compared to the true values measured in the 3D models. Nasal valve mCSA had a median percent error of 22.7% to 33.6% relative to the true values. Raters successfully used the software tool to identify subjects with nasal valve stenosis (ie, mCSA < 0.20 cm2) with a sensitivity of 83.3%, specificity ≥ 90.7%, and classification accuracy ≥ 90.0%. Interrater and intrarater agreements were high. CONCLUSION: This study demonstrates that airway CSAs in 3D models can be accurately estimated from depth maps. The development of artificial intelligence algorithms to compute depth maps may soon allow the quantification of airspace CSAs from clinical endoscopies.

Wound Healing Complications Associated with Staged Reconstruction after Facial Lentigo Maligna Resection.

Background: The rates and risk factors for wound complications following staged reconstruction after facial lentigo maligna (LM) resection have not been well described. Objectives: (1) To identify the rate and types of wound complications, including infection, graft necrosis, distal flap necrosis, hematoma, superficial epidermolysis, and seroma among patients undergoing staged reconstruction after resection of LM as documented in the surgeon's clinical notes within 30 days of the procedure. (2) To determine a threshold defect size that may predict the development of wound complications. Design and Outcomes: Retrospective review at an academic medical center of patients who underwent staged reconstruction after facial LM resection over a 5-year period. Results: Ninety-eight patients were identified with a mean age of 69.2 ± 13.6 years; 37% of patients were female. The most common defect sites were the cheek (n = 41; 42%) and nose (n = 22; 22%). Twenty-five of 98 patients (26%) demonstrated complications, with the most common being wound infection (36%) and graft necrosis (24%). Those receiving perioperative antibiotics had lower rates of complication (odds ratio [OR]: 0.36; 95% confidence interval [CI]: 0.13,0.96; p = 0.041). Defects greater than 2.7 cm in maximal diameter had the highest sensitivity for predicting complications. Conclusions: Patients undergoing staged reconstruction after facial LM resection have a high rate of wound complication (26%) and defect size > 2.7 cm may be an important risk factor.

Anatomical determinants of upper airway collapsibility in obstructive sleep apnea: A systematic review and meta-analysis.

Upper airway (UA) collapsibility is one of the key factors that determine the severity of obstructive sleep apnea (OSA). Interventions for OSA are aimed at reducing UA collapsibility, but selecting the optimal alternative intervention for patients who fail CPAP is challenging because currently no validated method predicts how anatomical changes affect UA collapsibility. The gold standard objective measure of UA collapsibility is the pharyngeal critical pressure (Pcrit). A systematic literature review and meta-analysis were performed to identify the anatomical factors with the strongest correlation with Pcrit. A search using the PRISMA methodology was performed on PubMed for English language scientific papers that correlated Pcrit to anatomic variables and OSA severity as measured by the apnea-hypopnea index (AHI). A total of 29 papers that matched eligibility criteria were included in the quantitative synthesis. The meta-analysis suggested that AHI has only a moderate correlation with Pcrit (estimated Pearson correlation coefficient r = 0.46). The meta-analysis identified four key anatomical variables associated with UA collapsibility, namely hyoid position (r = 0.53), tongue volume (r = 0.51), pharyngeal length (r = 0.50), and waist circumference (r = 0.49). In the future, biomechanical models that quantify the relative importance of these anatomical factors in determining UA collapsibility may help identify the optimal intervention for each patient. Many anatomical and structural factors such as airspace cross-sectional areas, epiglottic collapse, and palatal prolapse have inadequate data and require further research.

Toward automatic atlas-based surgical planning for septoplasty.

PURPOSE: Surgery for nasal airway obstruction (NAO) has a high failure rate, with up to 50% of patients reporting persistent symptoms postoperatively. Virtual surgery planning has the potential to improve surgical outcomes, but current manual methods are too labor-intensive to be adopted on a large scale. This manuscript introduces an automatic atlas-based approach for performing virtual septoplasties. METHODS: A cohort of 47 healthy subjects and 26 NAO patients was investigated. An atlas of healthy nasal geometry was constructed. The automatic virtual septoplasty method consists of a multi-stage registration approach to fit the atlas to a target NAO patient, automatically segment the patient's septum and airway, and deform the patient image to have a non-deviated septum. RESULTS: Our automatic virtual septoplasty method straightened the septum successfully in 18 out of 26 NAO patients (69% of cases). In these cases, the ratio of the higher to the lower airspace cross-sectional areas in the left and right nasal cavities improved from 1.47 ± 0.45 to 1.16 ± 0.33 in the region surrounding the septal deviation, showing that the nasal airway became more symmetric after virtual septoplasty. CONCLUSION: This automated virtual septoplasty technique has the potential to greatly reduce the effort required to perform computational fluid dynamics (CFD) analysis of nasal airflow for NAO surgical planning. Future studies are needed to investigate if virtual surgery planning using this method is predictive of subjective symptoms in NAO patients after septoplasty.

Narrowed Posterior Nasal Airway Limits Efficacy of Anterior Septoplasty.

Background: Predicting symptomatic relief after septoplasty has been difficult. Minimal cross-sectional area (mCSA) measured by acoustic rhinometry and airflow resistance (R) measured by rhinomanometry have been used to select surgical candidates with mixed success. An important assumption is that mCSA and resistance are tightly coupled, but studies have reported weak or no correlation. Recently, we proposed the Bernoulli Obstruction Theory as an explanation, where tight coupling between mCSA and R is only predicted below a critical mCSA (Acrit). Methods: The nasal airway and septum of 10 healthy subjects were reconstructed from computed tomography scans. Simulated anterior septal deviations of increasing severity were created. Computational fluid dynamics simulations were performed to quantify mCSA, resistance, and flow in the healthy septum model and four simulated septal deviation models for each subject (total of 50 models). Results: A tighter coupling between mCSA and resistance was found below Acrit, estimated to be 0.20 cm2 (a very severe deviation). Above Acrit, enlarging the mCSA had a smaller effect in patients with narrower cross-sectional area in the postvalve region (CSAPV). Conclusions: Two patterns of flow increase are expected with septoplasty. Below Acrit, enlarging mCSA predictably increases flow. Above Acrit, the effect size of increasing mCSA depends on CSAPV. Unrecognized small CSAPV may explain persistent sensation of nasal obstruction after septoplasty. Our data suggest that inferior turbinate reduction ipsilateral to a septal deviation may amplify airflow benefits after septoplasty in patients with a narrow CSAPV.

Effect of tube length on the buckling pressure of collapsible tubes.

BACKGROUND: The higher incidence of obstructive sleep apnea (OSA) in men than in women has been attributed to the upper airway being longer in men. The Starling resistor is the paradigm biomechanical model of upper airway collapse in OSA where a collapsible tube (representing the pharynx) is located between two rigid tubes (representing the nasal cavity and trachea). While the Starling resistor has been extensively studied due to its relevance to many physiological phenomena, the effect of tube length on tube collapsibility has not been quantified yet. METHODS: Finite element analysis of a 3-dimensional collapsible tube subjected to a transmural pressure was performed in ANSYS Workbench. The numerical methods were validated with in vitro experiments in a silicone tube whose modulus of elasticity (361 ± 28 kPa) and dimensions (length = 100 mm, diameter = 22.2 mm, and wall thickness = 1.59 mm) were selected so that tube compliance was similar to pharyngeal compliance in humans during sleep. The buckling pressure (transmural pressure at which the tube collapses) was quantified in tubes of three different diameters (10 mm, 16 mm, and 22.2 mm) and ten length-to-diameter ratios (L/D = 4 to 13), while keeping the wall-thickness-to-radius ratio constant at 0.143. RESULTS: The absolute value of the buckling pressure decreased from 4.7 to 3.3 cmH2O (461-324 Pa) when L/D increased from 4 to 13. The buckling pressure was nearly independent from tube length for L/D >10. CONCLUSIONS: Our finding that longer tubes are more collapsible than shorter tubes is consistent with the higher incidence of obstructive sleep apnea in males than females.

Objective measures in aesthetic and functional nasal surgery: perspectives on nasal form and function.

The outcomes of aesthetic and functional nasal surgery are difficult to assess objectively because of the intricate balance between nasal form and function. Despite historical emphasis on patient-reported subjective measures, objective measures are gaining importance in both research and the current outcomes-driven health care environment. Objective measures currently available have several shortcomings that limit their routine clinical use. In particular, the low correlation between objective and subjective measures poses a major challenge. However, advances in computer, imaging, and bioengineering technology are now setting the stage for the development of innovative objective assessment tools for nasal surgery that can potentially address some of the current limitations. Assessment of nasal form after aesthetic surgery is evolving from two-dimensional analysis to more sophisticated three-dimensional analysis. Similarly, assessment of nasal function is evolving with the introduction of computational fluid dynamics techniques, which allow for a detailed description of the biophysics of nasal airflow. In this article, we present an overview of objective measures in both aesthetic and functional nasal surgery and discuss future trends and applications that have the potential to change the way we assess nasal form and function.

Virtual septoplasty: a method to predict surgical outcomes for patients with nasal airway obstruction.

PURPOSE: A deviated nasal septum is the most common etiology for nasal airway obstruction (NAO), and septoplasty is the most common surgical procedure performed by ear-nose-throat surgeons in adults. However, quantitative criteria are rarely adopted to select patients for surgery, which may explain why up to 50% of patients report persistent or recurrent symptoms of nasal obstruction postoperatively. This study reports a systematic virtual surgery method to identify patients who may benefit from septoplasty. METHODS: One patient with symptoms of NAO due to a septal deviation was selected to illustrate the virtual surgery concept. Virtual septoplasty was implemented in three steps: (1) determining if septal geometry is abnormal preoperatively, (2) virtually correcting the deviation while preserving the anatomical shape of the septum, and (3) estimating the post-surgical improvement in airflow using computational fluid dynamics. Anatomical and functional changes predicted by the virtual surgery method were compared to a standard septoplasty performed independently from the computational analysis. RESULTS: A benchmark healthy nasal septum geometry was obtained by averaging the septum dimensions of 47 healthy individuals. A comparison of the nasal septum geometry in the NAO patient with the benchmark geometry identified the precise locations where septal deviation and thickness exceeded the healthy range. Good agreement was found between the virtual surgery predictions and the actual surgical outcomes for both airspace minimal cross-sectional area (0.05 cm2 pre-surgery, 0.54 cm2 virtual surgery, 0.50 cm2 actual surgery) and nasal resistance (0.91 Pa.s/ml pre-surgery, 0.08 Pa.s/ml virtual surgery, 0.08 Pa.s/ml actual surgery). CONCLUSIONS: Previous virtual surgery methods for NAO were based on manual edits and subjective criteria. The virtual septoplasty method proposed in this study is objective and has the potential to be fully automated. Future implementation of this method in virtual surgery planning software has the potential to improve septoplasty outcomes.

Normative ranges of nasal airflow variables in healthy adults.

PURPOSE: Virtual surgery planning based on computational fluid dynamics (CFD) simulations of nasal airflow has the potential to improve surgical outcomes for patients with nasal airway obstruction (NAO). Virtual surgery planning requires normative ranges of airflow variables, but few studies to date have quantified inter-individual variability of nasal airflow among healthy subjects. This study reports CFD simulations of nasal airflow in 47 healthy adults. METHODS: Anatomically accurate three-dimensional nasal models were reconstructed from cone beam computed tomography scans and used for steady-state inspiratory airflow simulations with a bilateral flowrate of 250 ml/s. Normal subjective sensation of nasal patency was confirmed using the nasal obstruction symptom evaluation and visual analog scale. Healthy ranges for several CFD variables known to correlate with subjective nasal patency were computed, including unilateral airflow, nasal resistance, airspace minimal cross-sectional area (mCSA), heat flux (HF), and surface area stimulated by mucosal cooling (defined as the area where HF > 50 W/m2). The normative ranges were targeted to contain 95% of the healthy population and computed using a nonparametric method based on order statistics. RESULTS: A wide range of inter-individual variability in nasal airflow was observed among healthy subjects. Unilateral airflow varied from 60 to 191 ml/s, airflow partitioning ranged from 23.8 to 76.2%, and unilateral mCSA varied from 0.24 to 1.21 cm2. These ranges are in good agreement with rhinomanometry and acoustic rhinometry data from the literature. A key innovation of this study are the normative ranges of flow variables associated with mucosal cooling, which recent research suggests is the primary physiological mechanism of nasal airflow sensation. Unilateral HF ranged from 94 to 281 W/m2, while the surface area stimulated by cooling ranged from 27.4 to 64.3 cm2. CONCLUSIONS: These normative ranges may serve as targets in future virtual surgery planning for patients with NAO.

A hierarchical stepwise approach to evaluate nasal patency after virtual surgery for nasal airway obstruction.

BACKGROUND: Despite advances in medicine and expenditures associated in treatment of nasal airway obstruction, 25-50% of patients undergoing nasal surgeries complain of persistent obstructive symptoms. Our objective is to develop a "stepwise virtual surgery" method that optimizes surgical outcomes for treatment of nasal airway obstruction. METHODS: Pre-surgery radiographic images of two subjects with nasal airway obstruction were imported into Mimics imaging software package for three-dimension reconstruction of the airway. A hierarchical stepwise approach was used to create seven virtual surgery nasal models comprising individual (inferior turbinectomy or septoplasty) procedures and combined inferior turbinectomy and septoplasty procedures via digital modifications of each subject's pre-surgery nasal model. To evaluate the effects of these procedures on nasal patency, computational fluid dynamics modeling was used to perform steady-state laminar inspiratory airflow and heat transfer simulations in every model, at resting breathing. Airflow-related variables were calculated for virtual surgery models and compared with dataset containing results of healthy subjects with no symptoms of nasal obstruction. FINDINGS: For Subject 1, nasal models with virtual septoplasty only and virtual septoplasty plus inferior turbinectomy on less obstructed side were within the healthy reference thresholds on both sides of the nasal cavity and across all three computed variables. For Subject 2, virtual septoplasty plus inferior turbinectomy on less obstructed side model produced the best result. INTERPRETATION: The hierarchical stepwise approach implemented in this preliminary report demonstrates computational fluid dynamics modeling ability to evaluate the efficiency of different surgical procedures for nasal obstruction in restoring nasal patency to normative level.

Options for upper lip reconstruction: a survey-based analysis.

BACKGROUND: Clinical factors such as size and location, but also surgeon experience and comfort level, may influence decisions in reconstructive methods. OBJECTIVE: To survey a select group of surgeons for their reconstructive choices for a moderate-sized upper lip defect. METHODS: Surveys were mailed to 313 facial plastic surgeons. Survey recipients were asked to rank reconstructive preferences for a specific upper lip defect. Response choices were correlated to predictor variables such as surgeon experience and comfort level. RESULTS: Survey response was 45.6%. Cheek advancement flap was the first choice in 34.4%, followed by Abbé flap (31.2%), myocutaneous rotation flap (20.5%), and nasolabial flap (13.9%), with the nasolabial flap being statistically the least popular (p<.01). For surgeons with more than 20 years' experience and those with less than 10 years' experience, the Abbé flap was the most common first choice (38.9% and 32.4%, respectively). For surgeons with 11 to 20 years experience, the cheek advancement flap was the most common first choice (46.2%). CONCLUSIONS: A poll of a select group of surgeons demonstrated variability in their choice of upper lip reconstruction options, although the nasolabial flap was found to be the least-chosen option. Trends in choices based upon experience and comfort level were demonstrated.

Evidence supporting functional rhinoplasty or nasal valve repair: A 25-year systematic review.

OBJECTIVE: To systematically review the existing literature supporting the efficacy of modern-day rhinoplasty techniques for treatment of nasal obstruction due to nasal valve compromise. DATA SOURCES: PubMed search of the English-language literature from January 1982 to August 2007 combined with manual review of citations within article bibliographies. REVIEW METHODS: A systematic review of the literature for the targeted objective was conducted. Citations acquired from the targeted search were filtered and primary articles were reviewed to abstract information including interventions and outcome measures. Articles were then assigned level-of-evidence grades as defined by the Oxford Centre for Evidence-Based Medicine. RESULTS: A total of 861 citations were generated and 291 abstracts were identified as potentially relevant articles. Of these abstracts, 82 articles merited full-text review. A total of 44 articles met inclusion criteria. The majority of the studies were classified as level 4 evidence, and only two studies met level 2b criteria. There was considerable variation in the quality of the studies within the level 4 category. All articles generally supported the effectiveness of functional rhinoplasty techniques for treatment of nasal obstruction. CONCLUSIONS: There is substantial level 4 evidence to support the efficacy of modern-day rhinoplasty techniques for treatment of nasal obstruction due to nasal valve collapse. More recent studies have incorporated validated patient-reported outcome measures, with more rigorous statistical analysis. Future study design improvements include the use of comparison cohorts and incorporating standardized objective outcome measures.

Outcome measures in facial plastic surgery: patient-reported and clinical efficacy measures.

OBJECTIVE: To survey the existing literature to identify, summarize, and evaluate procedure- and condition-specific outcome measures for use in facial plastic and reconstructive surgery. METHODS: A review of the English-language literature was performed to identify outcomes instruments specific for targeted facial plastic surgery interventions and conditions. A search was performed using MEDLINE (1950 to September 2007), CINAHL (Cumulative Index to Nursing & Allied Health) (1982 to September 2007), and PsychINFO (1806 to September 2007). Outcomes instruments were categorized as patient-reported or clinical efficacy measures (observer-reported or objective measures). Instruments were then categorized to include relevant details on the intervention, degree of validation, and subsequent use. RESULTS: Sixty-eight distinct instruments were identified (23 patient-reported, 35 observer-reported, and 10 objective measures), with some overlap among categories. Most patient-reported measures (76%) and half observer-reported instruments (51%) were developed in the past 10 years. The rigor of validation varied widely among measures, with formal validation being most common among the patient-reported outcome measures. CONCLUSIONS: Validated outcomes measures are present for many common facial plastic surgery conditions and have become more prevalent during the past decade, especially for patient-reported outcomes. Challenges remain in harmonizing patient-reported, observer-based, and other objective measures to produce standardized clinically meaningful outcome measures.

Behavior modification and risk perception in patients with nonmelanoma skin cancer.

CONTEXT: Nonmelanoma skin cancer (NMSC) is the most common cancer among humans, yet risk perceptions and preventive health behaviors in those who survive this cancer are relatively unknown. OBJECTIVES: To assess the impact of the disease and its treatment on sun-protective behaviors, general preventive health behaviors, and risk perception in NMSC patients, and to determine factors associated with behavioral change. DESIGN AND SETTING: A prospective study was conducted of 211 consecutive NMSC patients presenting to a dermatologic surgery clinic at a tertiary care university medical center from February 2005 to March 2006. These patients were all adults, were fluent in English, and had NMSC of the head and neck. Of the 211 eligible patients, complete data was obtained for 183 (87%). The most common reasons for dropout were voluntary withdrawal and incompletely answered surveys. INTERVENTION AND OUTCOME MEASURES: Surveys that assessed disease-specific quality of life (QoL), preventive health behaviors, sun-protective behaviors, and risk perception were administered before and after surgical treatment of NMSC. RESULTS: Sun-protective behaviors improved postsurgery even after controlling for seasons (P<0.001). Predictor factors associated with increased sun-protective behavior included poor skin tanning ability, summer season, no employment, less comorbid conditions, and previous NMSC treatment. Baseline QoL was not predictive of behavioral change. As for risk perception, respondents thought they were more likely than someone similar to themselves to develop future NMSCs but thought they had similar risks of developing melanoma or other non-skin cancers (P<0.001). NMSC patients demonstrated disease-specific behavior modifications by selectively improving their sun habits but showed no significant improvement in other preventive health behaviors. This finding is consistent with patients' specific perception of increased risk for future NMSCs, but surprisingly, not for melanoma. Increased patient education of associated cancer risks with NMSC is warranted. CONCLUSIONS: NMSC patients demonstrated disease-specific behavior modifications by selectively improving their sun habits but showed no significant improvement in other preventive health behaviors. This finding is consistent with patients' specific perception of increased risk for future NMSCs, but surprisingly, not for melanoma. Increased patient education of associated cancer risks with NMSC is warranted.

An Interactive, Patient-Specific Virtual Surgical Planning System for Upper Airway Obstruction Treatments.

Upper airway obstructions leading todifficulty breathing are significant problems that often require surgery to improve patient quality of life. However, these surgeries often have poor outcomes with little symptom improvement. This paper outlines the design of an interactive, patient-specific virtual surgical planning system that uses patient CT scans to generate three-dimensional representations of the airways and incorporates computational fluid dynamics (CFD) as a part of the surgical planning process. Individualized virtual surgeries can be performed by editing these models, which are then analyzed using CFD to compare pre- and post- surgery flow characteristics to assess patient symptom improvement. The prototype system shows significant promise by being intuitive, interactive, with a potential fast flow solver that provides near real-time feedback to the clinician.

Virtual Surgery for the Nasal Airway: A Preliminary Report on Decision Support and Technology Acceptance.

IMPORTANCE: Nasal airway obstruction (NAO) is a common problem that affects patient quality of life. Surgical success for NAO correction is variable. Virtual surgery planning via computational fluid dynamics (CFD) has the potential to improve the success rates of NAO surgery. OBJECTIVE: To elicit surgeon feedback of a virtual surgery planning tool for NAO and to determine if this tool affects surgeon decision making. DESIGN, SETTING, AND PARTICIPANTS: For this cross-sectional study, 60-minute face-to-face interviews with board-certified otolaryngologists were conducted at a single academic otolaryngology department from September 16, 2016, through October 7, 2016. Virtual surgery methods were introduced, and surgeons were able to interact with the virtual surgery planning tool interface. Surgeons were provided with a patient case of NAO, and open feedback of the platform was obtained, with emphasis on surgical decision making. MAIN OUTCOMES AND MEASURES: Likert scale responses and qualitative feedback were collected for the virtual surgery planning tool and its influence on surgeon decision making. RESULTS: Our 9 study participants were all male, board-certified otolaryngologists with a mean (range) 15 (4-28) number of years in practice and a mean (range) number of nasal surgeries per month at 2.2 (0.0-6.0). When examined on a scale of 1 (not at all) to 5 (completely), surgeon mean (SD) score was 3.4 (0.5) for how realistic the virtual models were compared with actual surgery. On the same scale, when asked how much the virtual surgery planning tool changed surgeon decision making, mean (SD) score was 2.6 (1.6). On a scale of 1 (strongly disagree) to 7 (strongly agree), surgeon scores for perceived usefulness of the technology and attitude toward using it were 5.1 (1.1) and 5.7 (0.9), respectively. CONCLUSIONS AND RELEVANCE: Our study shows positive surgeon experience with a virtual surgery planning tool for NAO based on CFD simulations. Surgeons felt that future applications and areas of study of the virtual surgery planning tool include its potential role for patient counseling, selecting appropriate surgical candidates, and identifying which anatomical structures should be targeted for surgical correction. LEVEL OF EVIDENCE: NA.

The skin cancer index: clinical responsiveness and predictors of quality of life.

OBJECTIVE: To establish the clinical responsiveness of the Skin Cancer Index (SCI), a new disease-specific quality of life (QOL) instrument, and to assess demographic and clinical factors which impact QOL in patients with nonmelanoma skin cancer (NMSC). STUDY DESIGN: Prospective study of 183 patients with NMSC of the face and neck referred to a tertiary care Mohs surgery clinic. METHODS: The SCI is a 15 item, validated, disease-specific QOL instrument with 3 distinct subscales, Emotion, Social, and Appearance. Higher scores reflect better QOL. The SCI and the Dermatology Life Quality Index (DLQI), a general dermatology instrument, was administered at initial consultation and 4 months after surgical treatment. Multivariate analysis was conducted to assess demographic and clinical factors predictive of QOL for both instruments. RESULTS: The SCI total score and all three subscale scores increased with treatment, demonstrating strong evidence of responsiveness over time (P < .001) in contrast with the DLQI (P = .46). Predictors of poorer QOL for the SCI included female sex and cancers located on the lip. Patients who demonstrated greatest improvement in QOL with treatment included those who were younger (<50 yr) and had lower reported household income. Also, first time NMSC patients and those patients who underwent less extensive reconstructions demonstrated greater improvements in QOL. CONCLUSION: The SCI is a sensitive and responsive QOL instrument for patients with NMSC. Distinct demographic and clinical variables that impact QOL have been demonstrated using this multidimensional, disease-specific instrument.