Learning curve of transoral robotic thyroidectomy.

BACKGROUND: Transoral thyroidectomy has superior cosmesis and better postoperative voice outcomes than conventional thyroidectomy. However, it usually requires a steep learning curve and longer operative time. The transoral robotic thyroidectomy (TORT) learning curve has not been well investigated. This study aimed to evaluate the TORT learning curve and factors affecting operative time. METHODS: We retrospectively studied 173 consecutive patients who underwent TORT with or without central neck dissection from July 2017 to August 2021. We assessed the TORT learning curve using operative time, complication rate, and surgical success (procedure conversion) rate. The operative time and surgical success rate learning curves were calculated using the cumulative summation (CUSUM) method. Additionally, we analyzed factors affecting operative time in TORT. RESULTS: Total thyroidectomy operative time was significantly longer than those of lobectomy and isthmusectomy (p < 0.001). In correlation analysis, a significantly positive correlation was observed between body mass index (BMI) and operative time (R2 = 0.04, p = 0.025). The TORT learning curve was 52 cases in the CUSUM operative time analysis. In the CUSUM surgical success rate chart, the turning point was the 55th case. Complication and procedure conversion rates were significantly decreased after the learning curve. CONCLUSIONS: The CUSUM learning curve of TORT was about 52-55 cases, and the operative time, total complication rate, and procedure conversion decreased significantly after the learning curve. The operative time was associated with the extent of thyroidectomy and BMI.

Evaluation of Voice and Vocal Fold Vibration after Thyroidectomy Using Two-Dimensional Scanning Digital Kymography and High-Speed Videolaryngoscopy.

OBJECTIVE: Vocal dysfunction is one of the major factors that affect the health-related quality of life of patients after thyroidectomy. Conventionally, voice changes after thyroidectomy have been evaluated by videostroboscopy and acoustic analysis. Recently, two-dimensional scanning digital kymography (2D DKG) and high-speed videolaryngoscopy (HSV) have been developed and have shown usefulness in accurately evaluating vocal fold vibration. This study aimed to evaluate changes of vocal fold vibration and voice after thyroidectomy using 2D DKG and HSV. MATERIALS AND METHODS: We evaluated the voice and vocal fold movement of 24 female patients who underwent thyroidectomy in a single tertiary hospital from December 2018 to October 2019. We obtained serial 2D DKG and HSV data one day before thyroidectomy, and 1 week and 1 month after surgery. We analyzed the peak glottal area of HSV, amplitude symmetry index, phase symmetry index, and open quotient using the 2D DKG data. The parameters were calculated at three levels of the vocal fold (line 1=anterior, line 2=middle, line 3=posterior). In the same period, we performed a voice analysis evaluating voice frequency, jitter, shimmer, and noise to harmonic ratio. We also assessed maximum phonation time and subjective voice changes with voice handicap index-10 questionnaires. RESULTS: Highest frequency (F-high), frequency range (F-range), and fundamental frequency (F0) decreased at 1 week and 1 month after thyroidectomy compared with preoperative values (P = 0.003, 0.004, <0.001 and P = 0.002, 0.015, 0.001 at 1 week and 1 month, respectively). The open quotient of 2D DKG in lines 1 and 2 increased at 1 week after thyroidectomy (P = 0.011, 0.006) and recovered to preoperative levels at 1 month postoperatively (P = 0.189, 0.153). Other quantitative measures by 2D DKG and HSV did not show significant changes between the preoperative and postoperative periods. In a correlation analysis between vocal parameters from the acoustic analysis and the values obtained from 2D DKG and HSV, significant negative correlations were observed between peak glottal area and three factors (F-high, F-range, and F0) at 1 month after surgery (r = -0.589, -0.529, -0.708; P = 0.002, 0.008, <0.001, respectively). There were positive correlations between phase symmetry indexes in lines 1 and 2 and shimmer at 1 week after thyroidectomy (r = 0.489, 0.425; P = 0.015, 0.038, respectively). Phase symmetry index in line 3 showed a significant negative correlation with maximum phonation time at both 1 week and 1 month after surgery (r = -0.497, -0.439; P = 0.013, 0.032, respectively). However, there was no correlation between total score on the voice handicap index-10 questionnaires and quantitative measurements of vocal fold vibration. CONCLUSION: 2D DKG and HSV may provide important information on vocal fold vibratory patterns after thyroidectomy, and measurements made with them were correlated with maximal phonation time and acoustic parameters such as F-high, F-range, F0, shimmer.

Transoral robotic selective neck dissection for papillary thyroid carcinoma: Dissection of Levels III and IV.

We present the operative procedure of transoral robotic selective neck dissection for papillary thyroid carcinoma. A 28-year-old woman, diagnosed with papillary thyroid carcinoma and lymph node metastasis at right level IV, underwent total thyroidectomy, central neck dissection, and selective neck dissection involving levels III and IV via the transoral robotic approach. A 1.5-2-cm central incision was made near the base of the lower lip frenulum, and two lateral incisions were made close to the oral commissure. An additional right axillary port was made to place a third robotic instrument for counter-traction. The operation was completed successfully without conversion to the conventional transcervical approach. The working space and surgical view were enough to perform selective neck dissection of levels III and IV. There were no major postoperative complications. Transoral robotic selective neck dissection of levels III and IV is feasible and safe in selected patients.

Clinical Characteristics of External Auditory Canal Foreign Bodies in Children and Adolescents.

OBJECTIVES: Foreign bodies (FBs) in external auditory canal (EAC) can occur at any age but are especially common in children and adolescents. The aims of the study were to evaluate the clinical characteristics of EAC FBs in children and adolescents and to discuss their proper management. METHODS: A retrospective medical chart review was performed on patients who were treated for EAC FBs in a tertiary referral center from January 2007 to December 2017. We investigated the parameters of age, sex, type of FB, sedation method, complications, and removal strategy. RESULTS: Of 284 patients, 176 (62.0%) were male. Peak incidences were noted at the ages of 3 to 6 years and 17 to 18 years. The frequently observed FBs were insects, followed by air-gun pellets, cotton balls, marbles, and earrings. Forty-one (14.4%) EAC FBs were removed with the naked eye, while 243 (85.6%) were removed under microscope in the otolaryngology department. Of these patients, 23 (9.5%) were administered sedatives and 1 (4.1%) needed general anesthesia. During or after the removal procedure, 4 (15.5%) patients had complications of EAC abrasion or laceration (42, 14.8%), and tympanic membrane perforation (2, 0.7%). CONCLUSIONS: External auditory canal FB showed a distinct characteristic of incidence regarding age, related to removal strategies. Characteristics of FB must be considered for safe removal.

Time-course changes of hormones and cytokines by lipopolysaccharide and its relation with anorexia.

We assessed the time course effects of lipopolysaccaride (LPS) on food intake, cytokines, and hormones in rats and evaluated the relation between LPS-induced anorexia and its possible causative factors. Food intake was reduced 2 h after LPS injection (500 microg/kg, intraperitoneally) and remained decreased for 24 h. Plasma TNF-alpha and IL-6 levels increased by LPS administration at 0.5 and 2 h, and at 2 and 4 h, respectively. Plasma leptin and glucose levels were elevated at 8 and 16 h, and insulin levels were elevated at 2, 4, 8, and 16 h in the LPS-injected group, as compared to the counterpart controls. IL-6 levels in the CSF were elevated at 2 and 4 h. Hypothalamic cytokines tended to increase as early as 0.5 h after LPS injection and remained increased until 16 h. LPS-induced anorexia was attenuated in insulin-deficient STZ rats and was abolished by insulin treatment. The hypothalamic expression of NPY, a target of insulin's anorexic effect, was decreased 2 h after LPS administration, and central NPY injection (3 nM) prevented LPS-induced anorexia. In conclusion, cytokines, insulin, and leptin levels evidence different time courses by LPS administration. In LPS-induced anorexia, insulin may constitute a newly found causative factor, whereas leptin appears to be uninvolved in an early period in rats.