Oncologic outcomes and surgical completeness of remote-access thyroidectomy: a systematic review and network meta-analysis.

BACKGROUND: The oncologic safety and surgical completeness of remote-access thyroidectomies are not yet clearly established. This study evaluates the oncologic outcomes and surgical completeness of three prevalent remote-access thyroidectomies: the gasless transaxillary approach (GTAA), bilateral axillo-breast approach (BABA), and transoral approach (TOA), in comparison with conventional transcervical thyroidectomy (CTT). METHODS: Literature searches were conducted in PubMed, EMBASE, and the Cochrane Library databases, covering the period from 2000 to 2023. Network meta-analyses were performed on selected studies, focusing on recurrence and surgical completeness. Surgical completeness was assessed using stimulated serum thyroglobulin levels and the count of retrieved lymph nodes. RESULTS: The review included 48 studies, encompassing a total of 16,356 patients. The number of retrieved lymph nodes was comparable among BABA, TOA, and CTT, while GTAA might be less effective. Stimulated serum thyroglobulin levels showed no significant differences across the four groups. However, the proportion of patients with stimulated thyroglobulin levels below 1.0 ng/mL was significantly lower in GTAA compared to the other groups. The overall recurrence rates were 1.31% for CTT, 0.89% for GTAA, 0.62% for BABA, and 0% for TOA, with no significant differences in recurrence rates when adjusted for follow-up duration. CONCLUSIONS: This study demonstrated that the oncologic outcomes of GTAA, BABA, and TOA are comparable to those of CTT, based on recurrence rates. In terms of surgical completeness, BABA and TOA showed equivalence to CTT, whereas GTAA might be inferior to the other techniques.

Feasibility of active surveillance in patients with clinically T1b papillary thyroid carcinoma ≤1.5 cm in preoperative ultrasonography: MASTER study.

Objective: Active surveillance (AS) is generally accepted as an alternative to immediate surgery for papillary thyroid carcinoma (PTC) measuring ≤1.0 cm (cT1a) without risk factors. This study investigated the clinicopathologic characteristics of PTCs measuring ≤2.0 cm without cervical lymph node metastasis (cT1N0) by tumor size group to assess the feasibility of AS for PTCs between 1.0 cm and 1.5 cm (cT1b≤1.5). Design: This study enrolled clinically T1N0 patients with preoperative ultrasonography information (n= 935) from a cohort of 1259 patients who underwent lobectomy and were finally diagnosed with PTC from June 2020 to March 2022. Results: The cT1b≤1.5 group (n = 171; 18.3 %) exhibited more lymphatic invasion and occult central lymph node (LN) metastasis with a higher metastatic LN ratio than the cT1a group (n = 719; 76.9 %). However, among patients aged 55 years or older, there were no significant differences in occult central LN metastasis and metastatic LN ratio between the cT1a, cT1b≤1.5, and cT1b>1.5 groups. Multivariate regression analyses revealed that occult central LN metastasis was associated with age, sex, tumor size, extrathyroidal extension, and lymphatic invasion in patients under 55, while in those aged 55 or older, it was associated only with age and lymphatic invasion. Conclusion: For PTC patients aged 55 years or older with cT1b≤1.5, AS could be a viable option due to the absence of a significant relationship between tumor size and occult central LN.

Long-term functional swallowing and speech outcomes after transoral robotic surgery for oropharyngeal cancer.

Objectives: Transoral robotic surgery (TORS) has emerged as a minimally invasive approach for oropharyngeal cancer, aiming to improve functional preservation and reduce morbidity. However, the long-term effects on speech and swallowing, crucial aspects of quality of life, remain unclear. This study investigates the long-term functional swallowing and speech outcomes of TORS for oropharyngeal cancer. Methods: We retrospectively reviewed 41 patients diagnosed with oropharyngeal squamous cell carcinoma who underwent TORS from 2010 to 2018. Tongue mobility, articulation, verbal diadochokinesis, reading speed, and modified barium swallowing tests were performed 2-3 years post-operatively to assess long-term speech and swallowing function. Results: The mean age was 57.7 ± 9.9 years, and the male to female ratio was 34:7. The palatine tonsil was the most common tumor site (73.2%), followed by the base of tongue (22.0%). Concurrent neck dissection was performed in 97.6% of patients, and adjuvant radiation or chemoradiation was administered to 36 patients (87.8%). Tongue mobility, articulation, verbal diadochokinesis, and reading speed were comparable to normal population. Modified barium swallowing tests revealed acceptable outcomes in most patients; only one patient (2.4%) required a percutaneous endoscopic gastrostomy tube. Notably, no permanent tracheostomies were necessary. Conclusions: Long-term speech and swallowing functions were preserved in most patients treated with TORS for oropharyngeal cancer. TORS is an excellent treatment modality for oropharyngeal cancer in terms of functional outcomes.

Surgical Training Using Augmented Reality-Based Optical Head-Mounted Displays: A Pilot Study.

While the educational benefits of the modern techniques such as virtual reality (VR) or augmented reality (AR) have been suggested, there is still a lack of reports on actual surgeons' experiences. In this study, we evaluated the effectiveness of a holographic AR-based surgical training in tonsillectomy. Two otolaryngologists, 1 trainee and 1 instructor, performed 5 tonsillectomies using an AR headset (HoloLens 2, Microsoft, USA). The trainee wore the AR headset to share the surgical view through front camera while the instructor remotely accessed the device using the Microsoft Teams program and provided real-time guidance. The AR-based surgical training offered several advantages, including direct real-time guidance for the trainee and clear instructions without disturbing the surgical process. However, there were also drawbacks, such as the front camera not always matching the trainee's view and some difficulty with focusing, depending on the depth of the oral cavity. Our study suggests that AR devices are a feasible and alternative method for surgical training. With the ability to provide clear guidance, even from a distance, this technology has the potential to revolutionize surgical training in the future.

Clinical impact of coexistent chronic lymphocytic thyroiditis on central lymph node metastasis in low- to intermediate-risk papillary thyroid carcinoma: The MASTER study.

BACKGROUND: The clinicopathological impact of chronic lymphocytic thyroiditis on patients with papillary thyroid carcinoma patients is still controversial. This study aimed to evaluate the clinicopathologic differences and risk factors for central lymph node metastasis based on the presence of coexistent chronic lymphocytic thyroiditis in patients with low- to intermediate-risk papillary thyroid carcinoma. METHODS: The medical records of 1,022 patients with low- to intermediate-risk papillary thyroid carcinoma who underwent lobectomy and central neck dissection between June 2020 and March 2022 were reviewed. Differences in clinicopathological factors were analyzed in patients with papillary thyroid carcinoma with or without chronic lymphocytic thyroiditis. Furthermore, risk factors for central lymph node metastasis in patients with low- to intermediate-risk papillary thyroid carcinoma with or without chronic lymphocytic thyroiditis were evaluated. RESULTS: Among the 1,022 patients with low to intermediate-risk papillary thyroid carcinoma, 102 (10.0%) had coexisting chronic lymphocytic thyroiditis. Female sex (odds ratio = 3.536, P = .001, 95% confidence interval 1.781-8.069), a multifocal tumor (odds ratio = 2.162, P = .001, 95% confidence interval 1.358-3.395), and angiolymphatic invasion (odds ratio = 0.365, P < .001, 95% confidence interval 0.203-0.625) were independent factors associated with patients who had coexisting chronic lymphocytic thyroiditis compared to those without chronic lymphocytic thyroiditis. There were 358 (35%) patients who had central lymph node metastasis. Multivariate analysis showed that younger age (odds ratio = 0.667, P = .013, 95% confidence interval 0.482-0.555), male sex (odds ratio = 0.549, P < .001, 95% confidence interval 0.402-0.751), tumor size >1 cm (odds ratio = 1.454, P = .022, 95% confidence interval 1.053-2.003), extrathyroidal extension (odds ratio = 1.874, P < .001, 95% confidence interval 1.414-2.486), and angiolymphatic invasion (odds ratio = 3.094, P < .001, 95% confidence interval 2.339-4.101) were risk factors for central lymph node metastasis. Angiolymphatic invasion (odds ratio = 11.184, P < .001, 95% confidence interval 3.277-46.199) was identified as the sole independent risk factor for central lymph node metastasis in patients with papillary thyroid carcinoma with coexisting chronic lymphocytic thyroiditis. CONCLUSION: Our data suggest that patients with low to intermediate-risk papillary thyroid carcinoma with coexistent chronic lymphocytic thyroiditis exhibit different clinical features than patients with papillary thyroid carcinoma without chronic lymphocytic thyroiditis. Additionally, the presence of chronic lymphocytic thyroiditis may be considered a potential factor against central lymph node metastasis.

Comparison of postoperative pain between transoral and conventional thyroidectomy: a propensity score-matched analysis.

BACKGROUND: The extent of postoperative pain following transoral thyroidectomy is not well-understood and remains a subject of debate. This study aims to analyze and compare postoperative pain levels between patients undergoing transoral and conventional transcervical thyroidectomy. METHODS: A prospective evaluation on postoperative pain was conducted in 310 patients undergoing conventional thyroidectomy and 194 undergoing transoral thyroidectomy. Pain levels were evaluated using the numerical rating scale (NRS, ranging from 0 to 10) through preoperative and postoperative questionnaires at specified time points: 1, 3, and 6 days, and 1 and 3 months following surgery. Propensity score-matched analysis was carried out based on six covariates: sex, age, body mass index, extent of thyroidectomy, tumor size, and central neck dissection. RESULTS: After propensity score matching based on the six covariates, 121 patient pairs were identified from each group. Within this matched cohort, postoperative pain scores significantly worsened 1 day after surgery but showed progressive recovery up to 3 months post-surgery in both groups. The transoral group exhibited higher postoperative pain scores than the conventional group from day 1 (4.43 ± 2.6 vs. 3.11 ± 2.5, p < 0.001) to day 6 (1.76 ± 1.9 vs. 1.13 ± 1.6, p = 0.016) post-surgery, with no significant difference noted at 1 month. Among transoral procedures, pain scores were significantly higher for the endoscopic approach compared to the robotic approach on days 1 (5.52 ± 2.3 vs. 4.29 ± 2.3, p = 0.028) and 3 (3.52 ± 2.5 vs. 2.64 ± 2.0, p = 0.047) post-surgery. CONCLUSIONS: Postoperative pain was significantly higher in transoral thyroidectomy compared to conventional thyroidectomy up to 6 days post-surgery. Within the transoral group, the robotic procedure resulted in lower pain levels than the endoscopic approach during the early postoperative period.

Comparison of surgical outcomes of transoral robotic and endoscopic thyroidectomy: A systematic review and network meta-analysis.

This study aimed to compare surgical outcomes of transoral robotic thyroidectomy (TORT) and transoral endoscopic thyroidectomy vestibular approach (TOETVA), concurrently compared with conventional transcervical thyroidectomy (CTT). A network meta-analysis, comprising 23 studies, was performed in this study. The operative time of the CTT group was significantly shorter than that of the TOETVA and TORT groups. The hospital stay of the TOETVA group was significantly longer than that of the CTT group. Rates of transient recurrent laryngeal nerve palsy and total complications were higher in association with TOETVA than with TORT. No significant differences were found between the three groups in intraoperative blood loss, retrieved lymph nodes, postoperative pain, and other complications. Cosmetic satisfaction was significantly superior with TORT and TOETVA than with CTT. Compared with CTT, TOETVA and TORT showed superior cosmesis but no significant difference in surgical outcomes except for operative time and hospital stay.

Longitudinal Changes in Quality of Life Before and After Thyroidectomy in Patients With Differentiated Thyroid Cancer.

OBJECTIVE: The objective of this prospective study was to assess longitudinal variations in health-related quality of life (HR-QOL) in patients diagnosed with differentiated thyroid cancer (DTC) before and after thyroidectomy. METHODS: A cohort of 185 DTC patients who underwent thyroidectomy between January 2013 and December 2017 and who completed all necessary questionnaires was evaluated. Their HR-QOL was gauged using the University of Washington Quality of Life questionnaire (UW-QOL) and the City of Hope Quality of Life-Thyroid Version questionnaire (QOL-TV) both prior to surgery and at 3 months, 6 months, 1 year, 2 years, 3 years, and 5 years postoperatively. RESULTS: Out of 185 patients, 150 (81.1%) were female, with an average age of 48.7 ± 12.9 years. For both UW-QOL and QOL-TV, the total composite QOL scores notably declined from preoperative levels to 3 months postoperatively, then gradually improved over 5 years, ultimately exceeding preoperative scores. Factors such as total thyroidectomy, radioactive iodine (RAI) ablation, and postoperative hypoparathyroidism were associated with lower physical composite QOL scores. Patients who underwent remote-access thyroidectomy expressed significantly higher satisfaction with appearance compared with those who had conventional thyroidectomy. Mood and anxiety were major clinical concerns both before and after surgery, showing considerable improvement postoperatively. CONCLUSION: For DTC patients, HR-QOL experienced a significant drop 3 months postsurgery, subsequently showing gradual improvement, surpassing preoperative QOL by 5 years. Factors contributing to improved physical QOL included the utilization of remote-access thyroidectomy, less extensive thyroidectomy, and the absence of RAI ablation and hypoparathyroidism.

Evaluation of the validity and reliability of a self-assessment questionnaire for cosmetic outcomes after thyroidectomy: a cross-sectional validation study.

PURPOSE: The Self-Assessment Questionnaire for Cosmetic Outcomes (SAQCO) was developed by us to evaluate the cosmetic outcome of patients after thyroidectomy. This study aimed to examine the reliability and validity of SAQCO. METHODS: We analyzed the cosmetic outcomes of 368 patients who underwent thyroidectomy and completed the SAQCO 1 year after surgery. The one-dimensionality, reliability, and validity of SAQCO were assessed using factor analysis models, Cronbach's alpha, and test-retest statistics. The differences in cosmesis indices between patient characteristics and surgical parameters were analyzed through comparative and regression analyses. RESULTS: The unidimensional convergence of SAQCO was examined. A Cronbach's alpha of 0.91, strong item-total correlation values (from 0.77 to 0.89), and a test-retest correlation value of 0.86 indicated the internal consistency and reliability of the SAQCO. The cosmesis index was significantly highest in the transoral (92.3 points) and transaxillary groups (90.9 points), followed by the postauricular (84.8 points) and transcervical groups (76.4 points). CONCLUSION: This study examined the reliability and validity of the SAQCO and showed that it is a suitable questionnaire for assessing cosmetic satisfaction of patients after thyroidectomy. The transoral and transaxillary approaches yield significantly superior cosmetic results compared to the conventional transcervical and postauricular approaches.

Patient-reported swallowing outcomes after transoral robotic thyroidectomy: Comparison with conventional transcervical thyroidectomy.

BACKGROUND: This study aimed to evaluate the swallowing outcomes after transoral robotic thyroidectomy (TORT) and compare them with those of conventional transcervical thyroidectomy. METHOD: We enrolled 146 patients who underwent thyroidectomy (73 TORT; 73 conventional approach). We prospectively analyzed swallowing outcomes using the Swallowing Impairment Index-6 (SIS-6) questionnaire, a patient-reported measure, before and 1, 3, and 6 days; 1, 3, and 6 months; and 1 year after surgery. Propensity score-matched analysis was performed using three covariates: age, sex, and extent of thyroidectomy. RESULTS: SIS-6 scores worsened significantly immediately after surgery and progressively recovered 1 year postoperatively in both groups. Propensity score matching generated two matched groups of 22 patients each. In the propensity score-matched samples, the SIS-6 scores did not differ between the TORT and conventional groups, except at 1 day postoperatively. CONCLUSION: Patient-reported swallowing outcomes of TORT were comparable to those of the conventional transcervical procedure.

Incidence and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy.

PURPOSE: The incidence and risk factors for hypoparathyroidism after total thyroidectomy is well-known. However, the characteristics of hypoparathyroidism and hypocalcemia after hemithyroidectomy have not been investigated well. In this study, we aimed to evaluate the incidence, characteristics, and risk factors of hypoparathyroidism and hypocalcemia after hemithyroidectomy. METHOD: We retrospectively analyzed the medical data of 321 patients who underwent hemithyroidectomy, with or without central neck dissection, from January 2012 to April 2019. We analyzed the serum intact parathyroid hormone (iPTH), calcium, and ionized calcium (iCa) levels serially (preoperatively and postoperatively on the operation day; days 1 and 3; and months 1, 3, 6, and 12) and evaluated risk factors for postoperative hypoparathyroidism and hypocalcemia. RESULTS: The mean iPTH and calcium levels decreased significantly after hemithyroidectomy on the operation day and postoperative days 1 and 3, and returned to the preoperative level at the postoperative 1-month follow-up. The mean iCa level decreased significantly on the operation day and postoperative day 1. Transient hypoparathyroidism and transient hypocalcemia occurred in 16 (5%) and 250 (78%) participants, and they recovered to normal levels postoperatively by 1 month. Eight (2.5%) patients had mild symptoms of hypocalcemia necessitating oral calcium supplementation. No permanent hypoparathyroidism or hypocalcemia was observed. Preoperatively low serum iPTH and calcium levels were associated with transient hypoparathyroidism and hypocalcemia after hemithyroidectomy. CONCLUSION: Approximately 5% and 2.5% of participants showed transient hypoparathyroidism and mild symptomatic hypocalcemia after hemithyroidectomy. The risk factors for transient hypoparathyroidism and hypocalcemia include preoperative low serum iPTH and calcium levels.

Impact of Alcohol Dehydrogenase 7 Polymorphism and Alcohol Consumption on Risk of Head and Neck Squamous Cell Carcinoma: A Korean Case-Control Study.

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is closely associated with alcohol consumption and individual genetic susceptibility, such as single nucleotide polymorphism (SNP) of alcohol dehydrogenase (ADH). This study aimed to investigate the association of ADH7 SNPs with the risk of HNSCC. METHODS: We analyzed ADH7 rs1573496C>G, rs3737482T>C, rs1154460G>A, and rs284787T>C SNPs in 250 patients with HNSCC and 322 controls in the Korean populations. Genotyping was conducted using the TaqMan assay. Linkage disequilibrium and haplotypes were analyzed. RESULTS: The odds ratios (OR) and 95% confidence intervals (CI) of the CT and CC genotypes of ADH7 rs3737482T>C were 0.48 (0.29-0.78) and 0.69 (0.49-0.96), indicating a significantly decreased risk. In SNP of rs1154460G>A, the OR and 95% CI of the AA genotype was 1.63 (1.11-2.40), showing a significant increase in the risk. Furthermore, SNPs of ADH7 rs3737482T>C and ADH7 rs1154460G>A exhibit synergistic interactions with alcohol composition on the risk of HNSCC. None of the haplotypes were associated with the risk of HNSCC. CONCLUSIONS: ADH7 rs3737482T>C and rs1154460G>A SNPs are associated with the risk of development of HNSCC in Koreans. They could serve as molecular biological markers to screen high-risk groups for HNSCC.

Serial Changes in Parotid Gland Volume and Symptoms After Radiation Therapy in Oropharyngeal Cancer.

Objective: To evaluate the serial changes in the volume of the parotid gland and clinical symptoms after a course of radiation therapy (RT) in patients with oropharyngeal cancer. Methods: A total of 33 patients who were diagnosed with oropharyngeal cancer and had been treated with RT or concurrent chemoradiation therapy were evaluated. Parotid gland volumes were measured serially by head and neck computed tomography with contrast-enhanced images before RT, and 6 months, 1 year, and 2 years after RT. Patients also filled out EORTC (European Organization for the Research and Treatment of Cancer) QLQ-C30 questionnaires on the quality of life (QOL) at the same time. This questionnaire included questions about salivary gland function: dry mouth, sticky saliva, and taste disorder. Higher scores on EORTC questionnaire translates to worse QOL. Results: All patients received more than 60 Gy irradiation in total. The mean volume of parotid gland decreased from 23.30 mL before RT to 15.80 mL, 15.93 mL, and 16.67 mL after 6 months, 1 year, and 2 years, respectively (P < 0.001 between pre-RT and all other 3 periods). The scores on the QOL questionnaire were higher (worsened QOL) at all 3 times after radiation than in the pre-RT period. The mean score of QOL increased from pre-RT to 2 years post-RT: "dry mouth" from 1.65 to 2.70, "sticky saliva" from 1.19 to 2.00, and "taste disorder" from 1.12 to 1.94. All 3 of these parameters were correlated with the volume of the parotid gland (P < 0.005 each). Conclusions: The volume of the parotid gland decreases significantly after RT for oropharyngeal cancer and does not recover significantly for at least 2 years. There was a significant correlation between decreased parotid volume and a lower QOL involving salivation.

Guideline for the Surgical Management of Locally Invasive Differentiated Thyroid Cancer From the Korean Society of Head and Neck Surgery.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Five-Year Oncologic Outcome and Surgical Completeness of Transoral Robotic Thyroidectomy for Papillary Thyroid Carcinoma: Comparison with Conventional Transcervical Thyroidectomy Using Propensity Score Matching.

OBJECTIVE: This study aimed to evaluate the oncological outcomes and surgical completeness of transoral robotic thyroidectomy (TORT) for papillary thyroid carcinoma (PTC) compared with conventional transcervical thyroidectomy. METHODS: We analyzed 489 patients with PTC who underwent thyroidectomy with or without central neck dissection (CND; 311 conventional thyroidectomy and 178 TORT) between January 2017 and December 2021. Patients with gross invasion of the surrounding structures, revision or completion thyroidectomy, and lateral neck dissection were excluded. Propensity score-matched analysis was performed using eight covariates, including age, sex, extent of thyroidectomy, tumor size, extrathyroidal extension (ETE), radioactive iodine (RAI) ablation, lymphovascular invasion (LVI), and CND. RESULTS: Before propensity score matching (PSM), age, male-to-female ratio, and body mass index were lower in the TORT group. The ratio of total thyroidectomy and CND, tumor size and bilaterality, LVI, and RAI ablation were higher in the conventional group. PSM generated two matched groups of 100 patients each. After PSM, significant differences between the two groups in the baseline analysis disappeared. In the matched samples, the recurrence rate (2% and 0% in the conventional and TORT groups, respectively) and recurrence-free survival curves did not differ between the two groups. The mean thyroid-stimulating hormone (TSH)-stimulated thyroglobulin level in the RAI group and TSH-suppressed thyroglobulin level in the non-RAI group were not different between the two groups. CONCLUSIONS: The 5-year oncologic outcomes and surgical completeness of TORT were comparable with those of conventional thyroidectomy in patients with small, localized, low-risk PTC when performed by experienced surgeons.

Age-Dependent Clinicopathological Characteristics of Patients with T1b Papillary Thyroid Carcinoma: Implications for the Possibility of Active Surveillance.

BACKGROUND: Active surveillance (AS) of low-risk T1a papillary thyroid carcinoma (PTC) is generally accepted as an alternative to immediate surgery. The cut-off in the size criterion for AS has recently been extended in select individuals, especially older patients. We evaluated the clinicopathological differences of T1b PTC according to age to investigate the possibility of AS in older patients. PATIENTS AND METHODS: From a cohort study of 1269 patients undergoing lobectomy for PTC, 1223 PTC patients with T1 stage disease (tumor ≤ 2 cm) were enrolled. The clinicopathological characteristics between T1a and T1b patients according to age were analyzed. RESULTS: Among the 1223 T1 cases, 918 (75.1%) were T1a (≤ 1 cm) and 305 (34.9%) T1b (> 1 and ≤ 2 cm). T1b PTC was associated with male sex, minimal extrathyroidal extension, lymphovascular invasion, occult central lymph node (LN) metastasis, and a higher number of metastatic LNs than T1a. However, in patients over 55 years of age, the clinicopathological features of the patients with T1a and T1b PTC were not significantly different except for minimal extrathyroidal extension, although many clinicopathological differences were observed in patients under 55 years of age. CONCLUSION: The clinicopathological features of patients with T1b PTC over 55 years of age are similar to those with T1a PTC and less aggressive than those with T1b PTC under 55 years of age. These findings suggest that AS may be possible in patients with T1b PTC over 55 years of age without high-risk features on preoperative examinations.

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.

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.