Intellectual Property in Facial Plastic and Reconstructive Surgery: The Importance and Process of Obtaining Intellectual Property Rights

Understanding the purpose and process of obtaining intellectual property rights (IPR) is fundamental to health care innovation. Facial plastic and reconstructive surgeons are natural innovators; however, knowledge deficit in this space may hinder the ability to move ideas from the "bench to bedside." Here we provide an overview of IPR, outlining the steps necessary to obtain intellectual property protection in an academic setting while highlighting recent U.S. Food and Drug Administration (FDA) approvals pertaining to facial plastic and reconstructive surgery.

Functional nasal surgery in the office-based setting

Objective

Nasal obstruction is a very common problem often addressed by functional nasal surgery. Increasingly, these procedures are being performed in the office setting secondary to decreased down time, cost, and obviation of general anesthesia. Our goal with this review is to discuss how to appropriately select patients for office-based procedures, what procedures may be considered, and current outcomes with in-office functional nasal surgery.

Data Sources

PubMed, Scopus, Google Scholar.

Methods

Research databases were searched for articles discussing techniques for performing functional nasal surgery in an office setting, and outcomes of various in-office functional nasal procedures.

Results

Studies found and included in this review discuss many aspects of office-based functional nasal surgery, including practical points on patient selection and office set-up, what procedures can safely be performed, and outcomes of different techniques to address specific problems. Broadly, procedures amenable to performance in the office address the internal and external nasal valves, the nasal septum, and the inferior turbinates.

Conclusion

A wide range of techniques to aaddress the nasal valves, septum, and inferior turbinates can be performed in a safe and effective manner without the need for an operative suite.

Volumetric Accuracy Analysis of Virtual Safety Barriers for Cooperative-Control Robotic Mastoidectomy

HYPOTHESIS

Virtual fixtures can be enforced in cooperative-control robotic mastoidectomies with submillimeter accuracy.

BACKGROUND

Otologic procedures are well-suited for robotic assistance due to consistent osseous landmarks. We have previously demonstrated the feasibility of cooperative-control robots (CCRs) for mastoidectomy. CCRs manipulate instruments simultaneously with the surgeon, allowing the surgeon to control instruments with robotic augmentation of motion. CCRs can also enforce virtual fixtures, which are safety barriers that prevent motion into undesired locations. Previous studies have validated the ability of CCRs to allow a novice surgeon to safely complete a cortical mastoidectomy. This study provides objective accuracy data for CCR-imposed safety barriers in cortical mastoidectomies.

METHODS

Temporal bone phantoms were registered to a CCR using preoperative computed tomography (CT) imaging. Virtual fixtures were created using 3D Slicer, with 2D planes placed along the external auditory canal, tegmen, and sigmoid, converging on the antrum. Five mastoidectomies were performed by a novice surgeon, moving the drill to the limit of the barriers. Postoperative CT scans were obtained, and Dice coefficients and Hausdorff distances were calculated.

RESULTS

The average modified Hausdorff distance between drilled bone and the preplanned volume was 0.351 ± 0.093 mm. Compared with the preplanned volume of 0.947 cm3, the mean volume of bone removed was 1.045 cm3 (difference of 0.0982 cm3 or 10.36%), with an average Dice coefficient of 0.741 (range, 0.665-0.802).

CONCLUSIONS

CCR virtual fixtures can be enforced with a high degree of accuracy. Future studies will focus on improving accuracy and developing 3D fixtures around relevant surgical anatomy.

One hundred and one consecutive transoral endoscopic parathyroidectomies via the vestibular approach for PHPTH: a worldwide multi-institutional experience

IMPORTANCE

The transoral vestibular approach for thyroid and parathyroid surgery is being adopted rapidly world-wide. Currently there is a paucity of information on this approach for primary hyperparathyroidism (PHPTH). If this approach is safe and efficacious it would provide patients a completely scarless option for parathyroidectomy.

OBJECTIVE

To determine whether parathyroidectomy via the transoral vestibular approach can be successfully done in a safe and efficient manner.

DESIGN

Consecutive case series of 101 transoral parathyroidectomies performed over a two-year period.

SETTING

Multi-institutional, academic, high-volume transoral thyroidectomy centers from the USA, Israel, and Thailand.

PARTICIPANTS

A consecutive series of adult patients with a biochemical diagnosis of classic PHPTH and who met criteria for parathyroidectomy based on established international consensus for surgery for PHPTH. All patients also had well-localized single adenomas on at least two preoperative imaging studies.

INTERVENTION

Transoral endoscopic parathyroidectomy vestibular approach.

MAIN OUTCOMES AND MEASURES

Surgical success rate defined by immediate intra or post-operative return to normal PTH values. Surgical complications including recurrent laryngeal nerve injury, permanent hypoparathyroidism, and infection.

RESULTS

Of the 101 consecutive transoral parathyroidectomy patients 84% were female with an average age of 54.23 ± 11.0 years and an average BMI of 27.35 ± 6.19. Ninety-nine out of the 101 patients had immediate return to normal PTH after resection for a surgical success rate of 98%. There were no permanent recurrent laryngeal nerve injuries, one temporary nerve palsy, and no permanent hypoparathyroidism. The median operative time dropped from 130.5 min (IQR 86) to 66.5 min (IQR 56) between the first- and second-half of cases.

CONCLUSION AND RELEVANCE

Transoral endoscopic parathyroidectomy via the vestibular approach is a scarless method of removing parathyroids that is clinically feasible, safe, and efficacious and is a reasonable option for focused minimally invasive parathyroidectomy that can be offered to select patients with PHPTH.

Preferences for thyroidectomy technique: Comparing traditional and transoral approaches

BACKGROUND

We investigated preferences between the transcervical and transoral thyroidectomy approach in the United States and Israel.

METHODS

An online survey assessing scar attitudes and surgical preferences, in English and Hebrew, was distributed on ThyCa.com and other platforms.

RESULTS

928 and 339 responses from the United States and Israel cohorts, respectively, were analyzed. In both countries, individuals without prior thyroidectomy preferred a scarless approach when hypothetical risks equaled those of traditional thyroidectomy (77% United States, 76% Israel, p = 0.61). U.S. respondents without thyroidectomy had greater preference to avoid a scar and would pay more to do so than those with thyroidectomy (both p < 0.001). Many respondents with prior thyroidectomy still expressed interest in scarless alternatives (57% United States).

CONCLUSIONS

Populations in Israel and the United States prefer scarless thyroidectomy when risks equal the traditional approach. While individuals without prior thyroidectomy are more likely to favor a scarless option, former thyroidectomy patients may have preferred avoiding a scar.

The variable direct cost and cost drivers of transoral endoscopic thyroidectomy vestibular approach

Background

As transoral endoscopic thyroidectomy vestibular approach grows in popularity, there is a need for data on cost in order to better characterize its value to patients. To this end, we compared the variable direct cost of transoral endoscopic thyroidectomy vestibular approach and transcervical approach thyroidectomy and determined which factors drive the increased cost for the transoral approach.

Methods

Patients undergoing thyroid lobectomy and total thyroidectomy that met inclusion criteria for transoral endoscopic thyroidectomy vestibular approach, including those patients that opted for management via the transcervical approach, between 8/2016 and 4/2019 were reviewed. The variable direct cost for the surgical encounter was collected and means were compared between the transoral and transcervical cohorts for lobectomy and total thyroidectomy respectively. The operative time independent variable direct cost was similarly compared between cohorts.

Results

Out of 238 patients, 118 (50%) were managed via transoral endoscopic thyroidectomy vestibular approach and 120 (50%) were managed via transcervical approach thyroidectomy. Mean variable direct cost, our primary outcome, was $4,455 (SD 1,129, 95% CI: 4,204-4,706) for transoral lobectomy and $3,179 (SD 687, 95% CI: 2,990-3,369) for transcervical lobectomy [t(132.05)=8.09, P<0.001] representing a difference in cost of $1,276 (SD 158, 95% CI: 964-1,587). Mean variable direct cost was $4,681 (SD 829, 95% CI: 4,405-4,957) for transoral total thyroidectomy and $3,645 (SD 876, 95% CI: 3,431-3,858) for transcervical total thyroidectomy [t(79.92)=5.98, P<0.001], representing a difference in cost of $1,036 (SD 173, 95% CI: 691-1,381). Differences in energy devices alone account for $487.53 and $447.96 of the cost differences, respectively.

Conclusions

The differences in mean variable direct cost between transoral endoscopic vestibular approach and transcervical approach for lobectomy and total thyroidectomy were $1276 and $1036 respectively, amounts far less than some believe them to be. This data will be invaluable as we ultimately aim to define the value of transoral endoscopic thyroidectomy vestibular approach.

Association of Hypocalcemia and Magnesium Disorders With Thyroidectomy in Commercially Insured Patients

Importance

Hypocalcemia is a common complication of total thyroidectomy.

Objectives

To identify factors associated with hypocalcemia after total thyroidectomy and to explore the association between hypocalcemia, magnesium disorders, and costs of care.

Design, Setting, and Participants

A retrospective cross-sectional analysis was performed using data from the MarketScan Commercial Claim and Encounters database on 126 766 commercially insured patients younger than 65 years undergoing total thyroidectomy between January 1, 2010, and December 31, 2012. Statistical analysis was performed from January 1, 2016, to May 30, 2019.

Main Outcomes and Measures

Short- and long-term hypocalcemia and the costs of care were examined using multivariable regression modeling.

Results

Among the 126 766 patients in the study (81.6% women; mean age, 46.5 years [range, 18-64 years]), postoperative hypocalcemia was present in 19.1% of patients in the initial 30-day postoperative period and in 4.4% of patients at 1 year. Magnesium disorders were present in 2.1% of patients at the time of surgery. Short- and long-term hypocalcemia were significantly more likely in women (short-term: odds ratio [OR], 1.39 [95% CI, 1.29-1.50]; long-term: OR, 1.69 [95% CI, 1.52-1.89]), those younger than 40 years (short-term: OR for ages 40-64 years, 0.83 [95% CI, 0.78-0.87]; long-term: OR for ages 40-64 years, 0.73 [95% CI, 0.67-0.79]), those with a diagnosis of thyroiditis (short-term: OR, 1.48 [95% CI, 1.16-1.89]; long-term: OR, 1.60 [95% CI, 1.13-2.26]) or cancer (short-term: OR, 1.32 [95% CI, 1.05-1.67]; long-term: OR, 1.17 [95% CI, 0.83-1.63]), vitamin D deficiency (short-term: OR, 1.96 [95% CI, 1.74-2.21]; long-term: OR, 3.72 [95% CI, 3.30-4.18]), concurrent lateral neck dissection (short-term: OR, 1.51 [95% CI, 1.37-1.66]; long-term: OR, 1.95 [95% CI, 1.69-2.26]), concurrent central neck dissection (short-term: OR, 1.15 [95% CI, 1.07-1.24]; long-term: OR, 1.25 [95% CI, 1.12-1.40]), intraoperative parathyroid (short-term: OR, 1.58 [95% CI, 1.46-1.71]; and long-term: OR, 2.05 [95% CI, 1.82-2.31]) or recurrent laryngeal nerve injury (short-term: OR, 1.49 [95% CI, 1.27-1.74]; long-term: OR, 2.04 [95% CI, 1.64-2.54]), and magnesium disorders (short-term: OR, 8.40 [95% CI, 7.21-9.79]; long-term: OR, 25.23 [95% CI, 19.80-32.17]). Compared with the initial postoperative period, the odds of hypocalcemia decreased by 90.0% (OR, 0.10 [95% CI, 0.09-0.11]) at 6 months and 93.0% (OR, 0.07 [95% CI, 0.06-0.08]) at 1 year. After controlling for all other variables, magnesium disorders were associated with the highest odds of short- and long-term postoperative hypocalcemia. Hypocalcemia ($3392) and magnesium disorders ($14 314) were associated with increased mean incremental 1-year costs of care.

Conclusions and Relevance

Hypocalcemia is common after total thyroidectomy but resolves in most patients by 1 year. Magnesium disorders are significantly independently associated with short- and long-term hypocalcemia and are associated with greater costs of care. These data suggest a potentially modifiable target to reduce the incidence and cost of long-term hypocalcemia at patient and systemic levels.

Predictive model of operative time in transoral endoscopic thyroidectomy vestibular approach

BACKGROUND

Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA) has demonstrated excellent safety and is receiving wider use in North America. Understanding which factors lead to operative difficulty, as evaluated by operative time (OT), may help to improve safety and refine indications for this procedure.

METHODS

Cases of TOETVA performed at our institution were reviewed. Multivariate linear regression was performed using patient demographics, thyroid characteristics, and operative variables to predict OT.

RESULTS

A total of 207 cases were included for analysis. A multivariate linear regression model, controlling for age, sex, and BMI, was developed from 104 cases with an R² of 0.47 (p < 0.001). Cross-validation on 103 remaining cases showed root-mean-square error of 46.37. Total thyroidectomy and lobe size were the only significant predictors (p < 0.001).

CONCLUSIONS

We successfully developed a model to predict OT for TOETVA based on preoperative and operative variables. Lobe size, but not BMI, is a significant predictor of OT.

Transoral Thyroidectomy: Safety and Outcomes of 200 Consecutive North American Cases

BACKGROUND

North American adoption of the transoral endoscopic thyroidectomy vestibular approach (TOETVA) has been limited due to concerns regarding the generalizability of published outcomes, as data are predominantly from Asian cohorts with a different body habitus. We describe our experience with TOETVA in a North American population in the context of the conventional transcervical approach thyroidectomy (TCA).

STUDY DESIGN

Cases of TOETVA and TCA were reviewed from August 2017 to March 2020 at a tertiary care center. Outcomes included operative time, major (permanent recurrent laryngeal nerve (RLN) injury, permanent hypoparathyroidism, hematoma, conversion to open surgery), and minor complications. The TOETVA cohort was stratified into body mass index (BMI) classes of underweight/normal < 25 kg/m², overweight 25-29.9 kg/m², and obese ≥ 30 kg/m² for comparative analysis. Multivariable logistic regression analyses were performed for odds of cumulative complication.

RESULTS

Two hundred TOETVA and 333 TCA cases were included. There was no difference in incidence of major complications between the TOETVA and TCA cohorts (1.5% vs. 2.1%, p = 0.75). No difference was found in the rate of temporary RLN injury (4.5% vs. 2.1%, p = 0.124) or temporary hypoparathyroidism (18.2% vs. 12.5%, p = 0.163) for TOETVA and TCA, respectively. Surgical technique (TOETVA vs TCA) did not alter the odds of cumulative complication (OR 0.69 95% CI [0.26-1.85]) on logistic regression analysis. In the TOETVA cohort, higher BMI did not lead to a significantly greater odds of cumulative complication, 0.52 (95% CI [0.17-1.58]) and 1.69 (95% CI [0.74-3.88]) for the overweight and obese groups, respectively.

CONCLUSION

TOETVA can be performed in a North American patient population without a difference in odds of complication compared to TCA. Higher BMI is not associated with greater likelihood of complication with TOETVA.

Predictors of Free Flap Volume Loss in Nonosseous Reconstruction of Head and Neck Oncologic Defects

OBJECTIVES

Free tissue reconstruction of the head and neck must be initially overcorrected due to expected postoperative free flap volume loss, which can be accelerated by adjuvant radiation therapy. In this study, we aim to identify patient and treatment-specific factors that may significantly contribute to this phenomenon and translate these characteristics into a predictive model for expected percent free flap volume loss in a given patient.

METHODS

Patients with a history of oral cavity and/or oropharyngeal cancer who underwent nonosseous free flap reconstruction were reviewed between January 2009 and November 2018 at a tertiary care center. Demographics/characteristics, total radiation dose, radiation fractionation (RF), and pre/postradiation free flap volume as evaluated by computed tomography imaging were collected. Free flap volume was measured by a fellowship-trained neuroradiologist in all cases. Only patients receiving adjuvant radiotherapy with available pre/postradiation imaging were included. Multivariable linear regression modeling for prediction of free flap volume loss was performed with optimization via stepwise elimination.

RESULTS

Thirty patients were included for analysis. Mean flap volume loss was 42.7% ± 17.4%. The model predicted flap volume loss in a significant fashion (P = .004, R² = 0.49) with a mean magnitude of error of 9.8% ± 7.5%. Age (β = 0.01, P = .003) and RF (β = -0.01, P = .009) were individual predictors of flap volume loss.

CONCLUSIONS

Our model predicts percent free flap volume loss in a significant fashion. Age and RF are individual predictors of free flap volume loss, the latter being a novel finding that is also modifiable through hyperfractionation radiotherapy schedules.

Imaging and choosing the right patients for transoral endoscopic parathyroidectomy vestibular approach

Advances in imaging for preoperative localization have propelled the widespread adoption of minimally invasive/focused parathyroidectomy in primary hyperparathyroidism. Though it is performed through a relatively small incision, studies have shown that the presence of a neck scar increases attentional bias towards the neck resulting in compromised quality of life. Transoral endoscopic parathyroidectomy vestibular approach (TOEPVA) eliminates a neck scar. While indications for TOEPVA are the same as that of minimally invasive open parathyroidectomy, confident preoperative localization of the parathyroid with a surgeon performed ultrasound along with concordant localization with SPECT CT is an essential prerequisite before offering patients this approach for parathyroidectomy. Early data has demonstrated the feasibility and safety of this approach.

The role of surgeon-performed ultrasound in transoral endoscopic thyroidectomy vestibular approach (TOETVA)

Transoral Endoscopic Thyroidectomy Vestibular Approach (TOETVA) is a recently described surgical technique where the thyroid and central neck can be accessed without a cutaneous incision. To date nearly 700 cases have been described within the English literature demonstrating the feasibility, safety, and efficacy of the technique. As more institutions begin to adopt the surgical approach, it is important that surgeons pay close attention to appropriate patient selection and surgical optimization to prevent experience-related complications. A valuable tool to facilitate these considerations is the utilization of surgeon-performed ultrasonography (US). While the merits of surgeon-performed US are well-documented within head & neck endocrine surgery as a whole, its value may be of even greater importance when implementing a novel surgical technique such as TOETVA. Here we highlight and summarize the role of surgeon-performed US within head & neck endocrine surgery, focusing on how it may influence patient selection and surgical planning with TOETVA.

Simulations and simulators in head and neck endocrine surgery

Simulations and simulators have become an increasingly important tool in trainee education across many surgical disciplines, particularly for robotic and minimally invasive procedures. Thyroidectomy and parathyroidectomy are common procedures performed across multiple surgical disciplines, however, there is limited literature regarding training models/simulators for these operations. This is despite the advent and growing popularity of remote-access thyroidectomy techniques, where simulators may provide significant value in trainee education and safe implementation. Here we review the literature regarding available simulations/simulators in head and neck endocrine surgery for both conventional transcervical approaches and newer remote-access thyroidectomy techniques.

Image-Guided Mastoidectomy with a Cooperatively Controlled ENT Microsurgery Robot

Mastoidectomy is a common surgical procedure within otology. Despite being inherently well suited for implementation of robotic assistance, there are no commercially available robotic systems that have demonstrated utility in aiding with this procedure. This article describes a robotic technique for image-guided mastoidectomy with an experimental cooperatively controlled robotic system developed for use within otolaryngology-head and neck surgery. It has the ability to facilitate enhanced operative precision with dampening of tremor in simulated surgical tasks. Its kinematic design is such that the location of the attached surgical instrument is known with a high degree of fidelity at all times. This facilitates image registration and subsequent definition of virtual fixtures, which demarcate surgical workspace boundaries and prevent motion into undesired areas. In this preliminary feasibility study, we demonstrate the clinical utility of this system to facilitate performance of a cortical mastoidectomy by a novice surgeon in 5 identical temporal bone models with a mean time of 221 ± 35 seconds.

Starting a Transoral Thyroid and Parathyroid Surgery Program

Purpose of Review

To describe the necessary steps to facilitate safe implementation of a transoral thyroid and parathyroid surgery program.

Recent Findings

Transoral vestibular approaches to the central neck have been demonstrated to be safe and feasible, while avoiding the morbidity of a cutaneous scar. As operative volume expands from a select few high-volume centers, a framework for implementation has been recommended to allow the evidence-based outcomes to translate into clinical practice for new adopters of these techniques. These include securing institutional support, choosing the appropriate candidate (both patient and surgeon), appropriate case observation and instruction (live and cadaver), and adequate first-case preparation and knowledge of the learning curve(s) for the techniques.

Summary

The recommendations in this article provide a foundation from which a transoral thyroid and parathyroid program may be successfully built. An intricate understanding of conventional transcervical central neck surgery and institutional support are absolute prerequisites to safe and successful implementation of these transoral vestibular techniques.

Patient Eligibility for Transoral Endocrine Surgery Procedures in the United States

IMPORTANCE

Transoral endocrine surgery (TES) allows thyroid and parathyroid operations to be performed without leaving any visible scar on the body. Controversy regarding the value of TES remains, in part owing to the common belief that TES is only applicable to a small, select group of patients. Knowledge of the overall applicability of these procedures is essential to understand the operation, as well as to decide the amount of effort and resources that should be allocated to further study the safety, efficacy, and value of these operations.

OBJECTIVE

To determine what percentage of US patients undergoing thyroid and parathyroid surgery are eligible for TES using currently accepted exclusion criteria.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of 1000 consecutive thyroid and parathyroid operations (with or without neck dissection) performed between July 1, 2015, and July 1, 2018, at 3 high-volume academic US thyroid- and parathyroid-focused surgical practices (2 general surgery, 1 otolaryngology-head and neck endocrine surgery). Eligibility for TES was determined by retrospectively applying previously published exclusion criteria to the cases.

MAIN OUTCOMES AND MEASURES

The primary outcome was the percentage of thyroid and parathyroid cases eligible for TES. Secondary outcomes were a subgroup analysis of the percentage of specific types of cases eligible and the reasons for ineligibility.

RESULTS

The mean (SD) age of the 1000 surgical patients was 53 (15) years, mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 29 (7), and 747 (75.0%) of the patients were women. Five hundred fifty-eight (55.8%) of the patients were eligible for TES. Most patients with thyroid nodules with cytologically indeterminate behavior (165 of 217 [76.0%]), benign thyroid conditions (166 of 240 [69.2%]), and primary hyperparathyroidism (158 of 273 [57.9%]) were eligible for TES, but only 67 of 231 (29.0%) of patients with thyroid cancer were eligible. Among all 1000 cases reviewed, previous neck operation (97 of 441 [22.0%]), nonlocalized primary hyperparathyroidism (78 of 441 [17.7%]), and need for neck dissection (66 of 441 [15.0%]) were the most common reasons for ineligibility.

CONCLUSIONS AND RELEVANCE

More than half of all patients undergoing thyroid and parathyroid surgery in this study were eligible for TES. This broad applicability suggests that a prospective multicenter trial is reasonable to definitively study the safety, outcomes, and cost of TES.

Transoral Vestibular Thyroidectomy: Current State of Affairs and Considerations for the Future

CONTEXT

The transoral endoscopic thyroidectomy vestibular approach (TOETVA) is a recently described procedure for surgical management of select thyroid pathology without the need for a cutaneous scar. TOETVA is far from the first described remote-access approach to the thyroid. In fact, numerous such techniques have been described over the past 20 years, although none have gained wide-spread implementation in North America or Europe. TOETVA, with its rapid growth worldwide and excellent outcomes to date, however, may succeed where these prior described techniques have failed.

EVIDENCE ACQUISITION

The English literature was reviewed using the following keywords: transoral thyroidectomy, remote-access thyroidectomy, minimally-invasive thyroidectomy, and TOETVA. As three recent systematic reviews have been performed in regards to the technique, this manuscript does not seek to provide a fourth such text. Rather, here we summarize salient findings from these reviews and focus on candidates for the procedure, technique-specific characteristics which have led to TOETVA's early success, and prospects for the future.

EVIDENCE SYNTHESIS

TOETVA is the only thyroidectomy approach obviating the need for a cutaneous incision, and offers several advantages over prior described remote-access thyroidectomy techniques. These include a favorable anatomic surgical perspective, a comparatively short learning curve, no requirement for expensive instrumentation, and a broad inclusion criterion. These characteristics have facilitated the excellent surgical outcomes to date.

CONCLUSIONS

TOETVA is a suitable surgical option for a carefully selected patient population with proven safety and feasibility. The potential value of the procedure outside enhanced cosmesis continues to be defined.

Remote-Access Thyroidectomy: A Multi-Institutional North American Experience with Transaxillary, Robotic Facelift, and Transoral Endoscopic Vestibular Approaches

BACKGROUND

Many remote-access approaches (RAAs) to the thyroid have been described to circumvent anterior neck scarring, including the transaxillary, robotic facelift, and transoral endoscopic vestibular approaches. These techniques have been popularized in Asia, but adoption has been slow in North America. We aimed to examine multi-institutional North American outcomes with RAA thyroidectomy in the context of these institutions' transcervical approach (TCA) outcomes.

STUDY DESIGN

Cases of lobectomy and total thyroidectomy via transaxillary, robotic facelift, and transoral endoscopic vestibular approaches were reviewed. Demographic characteristics, outcomes, and complications were compared with the same measures in patients undergoing lobectomy and total thyroidectomy via TCA by the primary RAA surgeons at each institution. Patients who underwent parathyroidectomy or other concomitant neck dissection procedures were excluded.

RESULTS

Two hundred and sixteen RAA thyroidectomies were attempted (92 transoral endoscopic vestibular approaches, 70 transaxillary, and 54 robotic facelift) and 410 TCA thyroidectomies were performed. There was no difference in mean index nodule sizes between RAA (2.8 ± 1.6 cm) and TCA (2.9 ± 1.9 cm) cohorts (p = 0.72). Median operative times for lobectomy were 146 minutes (range 60 to 343 minutes) and 90 minutes (range 25 to 247 minutes) for the RAA and TCA cohorts, respectively (p < 0.0001). Median operative time for total thyroidectomy was 170 minutes (range 100 to 398 minutes) vs 126.5 minutes (range 51 to 260 minutes) for the RAA and TCA cohorts, respectively (p < 0.0001). There was no difference in the rates of permanent recurrent laryngeal nerve injury between the RAA (0 of 216 [0%]) and TCA (0 of 410 [0%]) cohorts (p = 0.99).

CONCLUSIONS

Remote-access approach thyroidectomy can be performed in a select North American patient population with outcomes comparable with TCA.

Applied Force during Piston Prosthesis Placement in a 3D-Printed Model: Freehand vs Robot-Assisted Techniques

OBJECTIVES

To describe a 3D-printed middle ear model that quantifies the force applied to the modeled incus. To compare the forces applied during placement and crimping of a stapes prosthesis between the Robotic ENT Microsurgery System ( REMS) and the freehand technique in this model.

STUDY DESIGN

Prospective feasibility study.

SETTING

Robotics laboratory.

SUBJECTS AND METHODS

A middle ear model was designed and 3D printed to facilitate placement and crimping of a piston prosthesis. The modeled incus was mounted to a 6-degree of freedom force sensor to measure forces/torques applied on the incus. Six participants-1 fellowship-trained neurotologist, 2 neurotology fellows, and 3 otolaryngology-head and neck surgery residents-placed and crimped a piston prosthesis in this model, 3 times freehand and 3 times REMS assisted. Maximum force applied to the incus was then calculated for prosthesis placement and crimping from force/torque sensor readings for each trial. Robotic and freehand outcomes were compared with a linear regression model.

RESULTS

Mean maximum magnitude of force during prosthesis placement was 126.4 ± 73.6 mN and 105.0 ± 69.4 mN for the freehand and robotic techniques, respectively ( P = .404). For prosthesis crimping, the mean maximum magnitude of force was 469.3 ± 225.2 mN for the freehand technique and 272.7 ± 97.4 mN for the robotic technique ( P = .049).

CONCLUSIONS

Preliminary data demonstrate that REMS-assisted stapes prosthesis placement and crimping are feasible with a significant reduction in maximum force applied to the incus during crimping with the REMS in comparison with freehand.

Real-time robotic airway measurement: An additional benefit of a novel steady-hand robotic platform

OBJECTIVE

Describe the secondary capability of a robotic system to provide real-time measurements of airway dimensions with high fidelity.

METHODS

Seven unique phantoms of laryngotracheal stenosis (LTS) were modeled using a computer-aided design tool and were three dimensionally printed. These stenoses were of different dimensions and orientations, and some were purposefully oblique. The dimensions of the stenoses were then measured with the novel Robotic ENT (Ear, Nose, and Throat) Microsurgery System (REMS; Galen Robotics, Inc., Sunnyvale, CA) because it is capable of tool position memory in three dimensional (3D) space. Five participants (two laryngologists, two otolaryngology-head and neck surgery residents, one neurotology fellow) measured each axis of stenosis (anteroposterior, lateral, and craniocaudal) three times for each of the seven stenosis phantoms. These measurements were then compared to the known design dimensions. Mean magnitude of error (MOE) and interrater reliability (IRR) using an intraclass correlation coefficient (ICC) were then calculated.

RESULTS

Mean MOE and standard deviation for all measurements was 0.306 ± 0.247 mm. Mean MOE was 0.374 ± 0.292 mm, 0.300 ± 0.237 mm, and 0.244 ± 0.185 mm for the anteroposterior, lateral, and craniocaudal dimensions of stenosis, respectively. Eighty-two percent of all measurements had MOE < 0.5 mm. ICC was 0.945 (95% confidence interval [CI]: 0.847-0.989), 0.995 (95% CI: 0.984-0.999), and 0.993 (95% CI: 0.987-0.999) for anteroposterior, lateral, and craniocaudal dimensions, respectively, indicating excellent agreement among participants.

CONCLUSION

The REMS can be used to reliably and accurately measure airway dimensions in 3D regardless of the orientation of stenosis. This ability may be easily extrapolated to the measurement of any airway lesion during laryngotracheal surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 129:324-329, 2019.

Anterior cervical incision-sparing thyroidectomy: Comparing retroauricular and transoral approaches

Objectives

The robotic retroauricular approach and transoral endoscopic thyroidectomy vestibular approach (TOETVA) have been employed to avoid anterior neck scarring in thyroidectomy with good success. However, outcomes have yet to be compared between techniques. We compare our initial clinical experience with these approaches for thyroid lobectomy at our institution.

Methods

A review of initial consecutive patients who underwent robotic facelift thyroidectomy (RFT) (August 2011–August 2016) at our institution was conducted. This was compared with the same number of initial consecutive patients who underwent TOETVA (September 2016–September 2017) at our institution. Demographics, operative time, pathology, complications, and learning curve were compared between cohorts. Learning curve was defined based on the slope of linear regression models of operative time versus case number.

Results

There were 20 patients in each cohort. There was no statistically significant difference in demographic data between cohorts. One hundred percent of RFT cases versus 95% TOETVA cases (P = .999) were completed without conversion to standard open technique with median operative times of 201 (124–293) minutes versus 188 (89–343) minutes with RFT and TOETVA, respectively (P = .36). There was no incidence of permanent recurrent laryngeal nerve injury in either cohort. The slopes of the regression models were 0.29 versus −8.32 (P = .005) for RFT and TOETVA, respectively.

Conclusion

RFT and TOETVA are safe and feasible options for patients motivated to avoid an anterior neck scar. However, the quicker learning curve without the need for a costly robotic system may make TOETVA the preferred technique for institutions wishing to perform anterior cervical incision‐sparing thyroidectomy.

Level of Evidence

4

Learning Curve for Transoral Endoscopic Thyroid Lobectomy

Objective To define the learning curve for transoral endoscopic thyroidectomy via the vestibular approach (TOETVA). Study Design Case series with planned data collection. Setting Tertiary care academic hospital. Subjects and Methods Included patients were those who met the 2015 American Thyroid Association guidelines for lobectomy and our group's previously documented indications for TOETVA. Operative time (incision to closure) was used as a surrogate for procedural proficiency and plotted as a function of case number to determine a learning curve. A simple moving average of operative time was then calculated, with the proficiency case defined as the case number where the slope of this curve changed. Demographic/characteristic data, outcomes, and complications were compared between the skill acquisition period (case 1 to proficiency case) and the proficiency period (remaining cases). A linear regression model was then used to calculate and compare the slopes of the skill acquisition and proficiency periods in the "operative time versus case number" plot. Results Thirty cases were attempted, with a procedural success rate of 29 of 30 (94%) and no incidence of permanent mental nerve or recurrent laryngeal nerve injury. The proficiency case was case 11. There was a statistically significant difference between the skill acquisition and proficiency periods in slopes of the linear regressions (-16.7 vs -0.3, respectively; P < .001) and median operative times (191 vs 119 minutes, P < .001). There was no difference in demographics, procedural success rate, or complication rate between the periods. Conclusions The learning curve for TOETVA was 11 cases for the surgeon evaluated in this series.

Completion thyroidectomy via the transoral endoscopic vestibular approach

The safety and efficacy of the transoral endoscopic thyroidectomy vestibular approach (TOETVA) continues to be verified with the growing literature in regards to the procedure. While early cases were thyroid lobectomies performed for benign disease, the indications for TOETVA have now expanded to include total thyroidectomy for select small well-differentiated thyroid cancers (DTCs). Oncologic efficacy of this procedure remains unproven at this time, as the procedure was described only recently. Furthermore, as many of the cases completed via TOETVA are often diagnostic lobectomies, the appropriate management for patients requiring or opting for further surgical intervention per American Thyroid Association (ATA) guidelines has not been established. Here we present a case of a diagnostic lobectomy via TOETVA followed by interval completion thyroidectomy via the same approach for minimally invasive Hurthle cell carcinoma. Postoperative ultrasound demonstrated no evidence of thyroid remnant and serum thyroglobulin without circulating anti-thyroid antibodies was 0.3 ng/mL (reference range, 1.5-38.5 ng/mL) following the patient's completion thyroidectomy.

Early outcomes in transoral vestibular thyroidectomy: Robotic versus endoscopic techniques

BACKGROUND

The transoral thyroidectomy vestibular approach has been utilized via both robotic (TORTVA) and endoscopic (TOETVA) techniques to perform thyroidectomy. However, there have been no studies evaluating outcomes between these approaches. Here we describe our outcomes for thyroid lobectomy with TORTVA and TOETVA.

METHODS

All cases of transoral vestibular approach thyroid lobectomy at Johns Hopkins Hospital were reviewed. Primary outcomes and demographic data were then compared between TORTVA and TOETVA.

RESULTS

Twenty-seven cases were identified, 7 using the robotic approach and 20 using the endoscopic approach. The procedural success rate for the robotic and endoscopic cohorts was 5 of 7 (71%) and 19 of 20 (95%), respectively (P = .15). There were no persistent nerve injuries, mental, or recurrent in either cohort. Median operative time for TOETVA was 188 minutes versus 322 minutes for TORTVA (P = .001).

CONCLUSION

Thyroid lobectomy can be safely performed via both techniques, although performed more quickly endoscopically, which is likely due in part to differences in the learning curves.

Central neck dissection via the transoral approach

There has been a strong impetus for the development of remote access approaches to the central neck. The primary motivation for this has been to alleviate the negative impact that some patients may perceive from a central neck scar. Numerous approaches have been described; however the only approach that provides midline access and equivalent visualization of the bilateral thyroid lobes and paratracheal basins is transoral neck surgery (TONS). TONS has been shown to be safe and effective in performing thyroidectomy, parathyroidectomy, and central neck dissection (CND) via both the endoscopic and robotic techniques. In contrast with other remote access techniques, it provides the surgeon with familiar views of the bilateral recurrent laryngeal nerves (RLN) at their insertion site in concert with equivalent access to both paratracheal basins, thus uniquely facilitating safe and comprehensive CND. Though feasible and safe, CND via TONS is not appropriate in all cases. CND via TONS should only be performed with concomitant transoral total thyroidectomy, either prophylactically if the surgeon routinely performs prophylactic CND, or therapeutically if there is newly found evidence of nodal metastasis in the central compartment at the time of surgery. We base these recommendations on both the recent American Head and Neck Society (AHNS) consensus statement for indications for transcervical CND and the baseline indications for TONS.

Indications and contraindications to transoral thyroidectomy

Patient motivation to avoid neck scarring has been a strong impetus in the development of remote access approaches to the thyroid, including transoral robotic or endoscopic thyroidectomy vestibular approach (TOR/ETVA). TOR/ETVA continues to become more prevalent given its early success in North America and the demonstration of its safety and efficacy in Asia. As more surgeons perform this procedure, it is important that specific and uniform indications and contraindications exist to prevent surgical complications due to poor patient selection. In this article, we review the existing English literature regarding TOR/ETVA and compile the inclusion and exclusion criteria of individual authors for both robotic and endoscopic techniques to date. We then resolve differences in the existing literature to provide recommended indications and contraindications to TOR/ETVA based on both our review and our own experience with TOR/ETVA to date. The following are our resultant recommended indications for TOR/ETVA: patient history of hypertrophic scarring or motivation to avoid a cervical neck incision with a maximal thyroid diameter ≤ 10 cm and dominant nodule ≤6 cm, with one of the following pathologic criteria; benign lesion, multinodular goiter, indeterminate nodule, or suspicious lesions/well-differentiated thyroid carcinomas ≤ 2 cm. Recommended contraindications to TOR/ETVA are as follows: history of head & neck surgery, history of head, neck, or upper mediastinal irradiation, inability to tolerate general anesthesia, evidence of clinical hyperthyroidism, preoperative recurrent laryngeal nerve palsy, lymph node metastasis, extrathyroidal extension including tracheal or esophageal invasion, oral abscesses, substernal thyroidal extension, or failure to meet inclusion criteria as above. Relative contraindications include smoking and other oral pathology, and surgeons should be aware that morbid obesity may make it difficult to raise skin flaps.

The robotic ENT microsurgery system: A novel robotic platform for microvascular surgery

OBJECTIVE

Assess the feasibility of a novel robotic platform for use in microvascular surgery.

STUDY DESIGN

Prospective feasibility study.

SETTING

Robotics laboratory.

METHODS

The Robotic ENT (Ear, Nose, and Throat) Microsurgery System (REMS) (Galen Robotics, Inc., Sunnyvale, CA) is a robotic arm that stabilizes a surgeon's instrument, allowing precise, tremor-free movement. Six microvascular naïve medical students and one microvascular expert performed microvascular anastomosis of a chicken ischiatic artery, with and without the REMS. Trials were blindly graded by seven microvascular surgeons using a microvascular tremor scale (MTS) based on instrument tip movement as a function of vessel width. Time to completion (TTC) was measured, and an exit survey assessed participants' experience. The interrater reliability of the MTS was calculated.

RESULTS

For microvascular-naïve participants, the mean MTS score for REMS-assisted trials was 0.72 (95% confidence interval [CI] 0.64-1.07) and 2.40 (95% CI 2.12-2.69) for freehand (P < 0.001). The mean TTC was 1,265 seconds for REMS-assisted trials and 1,320 seconds for freehand (P > 0.05). For the microvascular expert, the mean REMS-assisted MTS score was 0.71 (95% CI 0.15-1.27) and 0.86 (95% CI 0.35-1.37) for freehand (P > 0.05). TTC was 353 seconds for the REMS-assisted trial and 299 seconds for freehand. All participants thought the REMS was more accurate and improved instrument handling and stability. The intraclass correlation coefficient for MTS ratings was 0.914 (95% CI 0.823-0.968) for consistency and 0.901 (95% CI 0.795-0.963) for absolute value.

CONCLUSION

The REMS is a feasible adjunct for microvascular surgery and a potential teaching tool capable of reducing tremor in novice users. Furthermore, the MTS is a feasible grading system for assessing microvascular tremor.

LEVEL OF EVIDENCE

NA. Laryngoscope, 127:2495-2500, 2017.

DNA methylation detection using MS-qFRET, a quantum dot-based nanoassay

Detection of aberrant promoter hypermethylation of tumor suppressor genes can be used as a prognostic or predictive marker for carcinogenesis. Since epigenetic modifying agents are FDA approved for treatment of patients with myelodysplastic syndrome, laboratory correlative tools to monitor response to this targeted therapy are important. Methylation specific quantum dot fluorescence resonance energy transfer (MS-qFRET) is a nanotechnology assay that enables the detection of methylation and its changes in a sensitive, quantifiable manner. It utilizes quantum dot-mediated fluorescence resonance energy transfer to achieve highly sensitive detection of DNA methylation. Template DNA is first treated with sodium bisulfite such that unmethylated cytosines are converted to uracil while methylated cytosines remain unconverted. Thereafter, the converted template is amplified using biotinylated methylation-specific primers. Quantum dots, functionalized with streptavidin, serve both as a scaffold to capture amplicons and as a donor for transferring energy to the Cy5 acceptor that is incorporated into the amplicons during PCR. Thus, the status of DNA methylation can be determined according to the level of FRET. In this report, MS-qFRET is validated in cell lines and then used to detect the status of p15(INK4B) methylation in clinical samples from eight patients with acute myeloid leukemia.