Cost-Effectiveness of Diffusion Weighted MRI Versus Planned Second-Look Surgery for Cholesteatoma.

OBJECTIVE: To compare the cost-effectiveness of serial non-echo planar diffusion weighted MRI (non-EP DW MRI) versus planned second look surgery following initial canal wall up tympanomastoidectomy for the treatment of cholesteatoma. METHODS: A decision-analytic model was developed. Model inputs including residual cholesteatoma rates, rates of non-EP DW MRI positivity after surgery, and health utility scores were abstracted from published literature. Cost data were derived from the 2022 Centers for Medicare and Medicaid Services fee rates. Efficacy was defined as increase in quality-adjusted life year (QALY). One- and 2-way sensitivity analyses were performed on variables of interest to probe the model. Total time horizon was 50 years with a willingness to pay (WTP) threshold set at $50 000/QALY. RESULTS: Base case analysis revealed that planned second-look surgery ($11 537, 17.30 QALY) and imaging surveillance with non-EP DWMRI ($10 439, 17.26 QALY) were both cost effective options. Incremental cost effectiveness ratio was $27 298/QALY, which is below the WTP threhshold. One-way sensitivity analyses showed that non-EP DW MRI was more cost effective than planned second-look surgery if the rate of residual disease after surgery increased to 48.3% or if the rate of positive MRI was below 45.9%. A probabilistic sensitivity analysis at WTP of $50 000/QALY found that second-look surgery was more cost-effective in 56.7% of iterations. CONCLUSION: Non-EP DW MRI surveillance is a cost-effect alternative to planned second-look surgery following primary canal wall up tympanomastoidectomy for cholesteatoma. Cholesteatoma surveillance decisions after initial canal wall up tympanomastoidectomy should be individualized. LEVEL OF EVIDENCE: V.

Convolutional Neural Network-Based Deep Learning Engine for Mastoidectomy Instrument Recognition and Movement Tracking.

OBJECTIVE: To develop a convolutional neural network-based computer vision model to recognize and track 2 mastoidectomy surgical instruments-the drill and the suction-irrigator-from intraoperative video recordings of mastoidectomies. STUDY DESIGN: Technological development and model validation. SETTING: Academic center. METHODS: Ten 1-minute videos of mastoidectomies done for cochlear implantation by varying levels of resident surgeons were collected. For each video, containing 900 frames, an open-access computer vision annotation tool was used to annotate the drill and suction-irrigator class images with bounding boxes. A mastoidectomy instrument tracking module, which extracts the center coordinates of bounding boxes, was developed using a feature pyramid network and layered with DETECTRON, an open-access faster-region-based convolutional neural network. Eight videos were used to train the model, and 2 videos were used for testing. Outcome measures included Intersection over Union (IoU) ratio, accuracy, and average precision. RESULTS: For an IoU of 0.5, the mean average precision for the drill was 99% and 86% for the suction-irrigator. The model proved capable of generating maps of drill and suction-irrigator stroke direction and distance for the entirety of each video. CONCLUSIONS: This computer vision model can identify and track the drill and suction-irrigator from videos of intraoperative mastoidectomies performed by residents with excellent precision. It can now be employed to retrospectively study objective mastoidectomy measures of expert and resident surgeons, such as drill and suction-irrigator stroke concentration, economy of motion, speed, and coordination, setting the stage for characterization of objective expectations for safe and efficient mastoidectomies.

Cost-effectiveness of Canal Wall-Up vs Canal Wall-Down Mastoidectomy: A Modeling Study.

OBJECTIVE: To assess the relative lifetime costs, benefits, and cost-effectiveness between the 2 approaches, canal wall-up (CWU) and canal wall-down (CWD) tympanomastoidectomy, used in the treatment of cholesteatomas. STUDY DESIGN: Markov state transition model. SETTING: Tertiary academic health system. METHODS: A Markov state transition model was used to simulate outcomes across the patient lifetime. Outcome and complication probabilities were obtained from the existing literature. Costs were calculated from the payer perspective, with procedure, hospital, clinic, and physician cost derived from Medicare reimbursement. Quality-adjusted life years (QALYs) were used to represent effectiveness and utility. One-way and probability sensitivity analyses (PSAs) were conducted. RESULTS: The base case analysis, assuming a 40-year-old patient, yielded a lifetime cost of $14,214 for a patient treated with the CWU approach assuming second-look surgery and $22,290 with a CWD approach. CWU and CWD generated a benefit of 17.11 and 17.30 QALYs, respectively. The incremental cost-effectiveness ratio for CWU was $43,237 per QALY. The Monte Carlo PSA validated the base case scenario. Using a standard $50,000 willingness-to-pay threshold, CWD was the more cost-effective approach and was selected 54.8% of the time by the simulation. CONCLUSION: Both CWU and CWD were found to be cost-effective, with CWD being cost-effective 54.8% of the time at a WTP threshold of $50,000. The assumptions used in the analysis were validated by the results of 1-way and PSA.

Droplet and Aerosol Generation With Mastoidectomy During the COVID-19 Pandemic: Assessment of Baseline Risk and Mitigation Measures With a High-performance Cascade Impactor.

HYPOTHESIS: Aerosols are generated during mastoidectomy and mitigation strategies may effectively reduce aerosol spread. BACKGROUND: An objective understanding of aerosol generation and the effectiveness of mitigation strategies can inform interventions to reduce aerosol risk from mastoidectomy and other open surgeries involving drilling. METHODS: Cadaveric and fluorescent three-dimensional printed temporal bone models were drilled under variable conditions and mitigation methods. Aerosol production was measured with a cascade impactor set to detect particle sizes under 14.1 µm. Field contamination was determined with examination under UV light. RESULTS: Drilling of cadaveric bones and three-dimensional models resulted in strongly positive aerosol production, measuring positive in all eight impactor stages for the cadaver trials. This occurred regardless of using coarse or cutting burs, irrigation, a handheld suction, or an additional parked suction. The only mitigation factor that led to a completely negative aerosol result in all eight stages was placing an additional microscope drape to surround the field. Bone dust was scattered in all directions from the drill, including on the microscope, the surgeon, and visually suspended in the air for all but the drape trial. CONCLUSIONS: Aerosols are generated with drilling the mastoid. Using an additional microscope drape to cover the surgical field was an effective mitigation strategy to prevent fine aerosol dispersion while drilling.

Perioperative cost evaluation of canal wall down mastoidectomy.

INTRODUCTION: To evaluate perioperative costs of canal wall-down (CWD) mastoidectomy as an initial surgery compared to revision surgery following initial canal wall-up (CWU) mastoidectomy. METHODS: This study is a retrospective chart review of adult patients who underwent CWD mastoidectomy for chronic otitis media with or without cholesteatoma at a tertiary referral center. Patients were divided into groups that had previous CWU surgery and were undergoing revision CWD and those that were having an initial CWD mastoidectomy. Cost variables including previous surgeries, imaging costs, audiometric testing, and post-operative visits were compared between the two groups using t-test analysis. RESULTS: There was no significant difference with regards to the cost of post-operative visits, peri-operative imaging, or revision surgeries between the two groups. Hearing outcomes based on mean speech reception threshold (SRT) were not statistically different between the two groups (p = 0.087). There was a significant difference in total cost with the revision group having a higher mean cost by $6967.84, most of which was accounted for by the difference in the cost of the previous surgeries of $6488.53. CONCLUSIONS: The revision CWD surgery group had increased total cost that could be attributed to the cost of previous surgery. Increased peri-operative cost was not noted with the initial CWD surgery group for any individual variables examined. Initial CWD mastoidectomy should be considered in the proper patient population to help decrease healthcare costs.

Standard Setting of Competency in Mastoidectomy for the Cross-Institutional Mastoidectomy Assessment Tool.

OBJECTIVE: Competency-based surgical training involves progressive autonomy given to the trainee. This requires systematic and evidence-based assessment with well-defined standards of proficiency. The objective of this study is to develop standards for the cross-institutional mastoidectomy assessment tool to inform decisions regarding whether a resident demonstrates sufficient skill to perform a mastoidectomy with or without supervision. METHODS: A panel of fellowship-trained content experts in mastoidectomy was surveyed in relation to the 16 items of the assessment tool to determine the skills needed for supervised and unsupervised surgery. We examined the consensus score to investigate the degree of agreement among respondents for each survey item as well as additional analyses to determine whether the reported skill level required for each survey item was significantly different for the supervised versus unsupervised level. RESULTS: Ten panelists representing different US training programs responded. There was considerable consensus on cut-off scores for each item and trainee level between panelists, with moderate (0.62) to very high (0.95) consensus scores depending on assessment item. Further analyses demonstrated that the difference between supervised and unsupervised skill levels was significantly meaningful for all items. Finally, minimum-passing scores for each item was established. CONCLUSION: We defined performance standards for the cross-institutional mastoidectomy assessment tool using the Angoff method. These cut-off scores that can be used to determine when trainees can progress from performance under supervision to performance without supervision. This can be used to guide training in a competency-based training curriculum.

The effect of structured self-assessment in virtual reality simulation training of mastoidectomy.

PURPOSE: Virtual reality (VR) simulation surgical skills training is well established, but self-directed practice is often associated with a learning curve plateau. In this study, we investigate the effects of structured self-assessment as a means to improve performance in mastoidectomy training. METHODS: The study was a prospective, educational study. Two cohorts of novices (medical students) were recruited for practice of anatomical mastoidectomy in a training program with five distributed training blocks. Fifteen participants performed structured self-assessment after each procedure (intervention cohort). A reference cohort of another 14 participants served as controls. Performances were assessed by two blinded raters using a modified Welling Scale and simulator-recorded metrics. RESULTS: The self-assessment cohort performed superiorly to the reference cohort (mean difference of final product score 0.87 points, p = 0.001) and substantially reduced the number of repetitions needed. The self-assessment cohort also had more passing performances for the combined metrics-based score reflecting increased efficiency. Finally, the self-assessment cohort made fewer collisions compared with the reference cohort especially with the chorda tympani, the facial nerve, the incus, and the malleus. CONCLUSIONS: VR simulation training of surgical skills benefits from having learners perform structured self-assessment following each procedure as this increases performance, accelerates the learning curve thereby reducing time needed for training, and induces a safer performance with fewer collisions with critical structures. Structured self-assessment was in itself not sufficient to counter the learning curve plateau and for continued skills development additional supports for deliberate practice are needed.

Clinical Utility of Intraoperative Tympanomastoidectomy Assessment Using a Surgical Microscope Integrated with an Optical Coherence Tomography.

Significant technical and optical advances are required for intraoperative optical coherence tomography (OCT) to be utilized during otological surgeries. Integrating OCT with surgical microscopy makes it possible to evaluate soft tissue in real-time and at a high resolution. Herein, we describe an augmented-reality, intraoperative OCT/microscope system with an extended working distance of 280 mm, providing more space for surgical manipulation than conventional techniques. We initially performed ex vivo experiments to evaluate system performance. In addition, we validated the system by performing preliminary clinical assessments of tympanomastoidectomy outcomes in six patients with chronic otitis media. The system evaluated residual inflammation in the region-of-interest of the mastoid bone. Most importantly, the system intraoperatively revealed the connection between the graft and the remnant tympanic membrane. The extended working distance allows otological surgeons to evaluate the status of both the mastoid bone and tympanic membrane during manipulation, affording full intraoperative imaging.

Cross-Institutional Evaluation of a Mastoidectomy Assessment Instrument.

OBJECTIVE: The objective of this work is to obtain validity evidence for an evaluation instrument used to assess the performance level of a mastoidectomy. The instrument has been previously described and had been formulated by a multi-institutional consortium. DESIGN: Mastoidectomies were performed on a virtual temporal bone system and then rated by experts using a previously described 15 element task-based checklist. Based on the results, a second, similar checklist was created and a second round of rating was performed. SETTING: Twelve otolaryngological surgical training programs in the United States. PARTICIPANTS: In all, 65 mastoidectomy performances were evaluated coming from 37 individuals with a variety of temporal bone dissection experience, from medical students to attending physicians. Raters were attending surgeons from 12 different institutions. RESULTS: Intraclass correlation scores varied greatly between items in the checklist with some being low and some being high. Percentage agreement scores were similar to previous rating instruments. There is strong evidence that a high score on the task-based checklist is necessary for a rater to consider a mastoidectomy to be performed at the level of an expert but a high score is not a sufficient condition. CONCLUSIONS: Rewording of the instrument items to focus on safety does not result in increased reliability of the instrument. The strong result of the Necessary Condition Analysis suggests that going beyond simple correlation measures can give extra insight into grading results. Additionally, we suggest using a multiple point scale instead of a binary pass/fail question combined with descriptive mastery levels.