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.

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.

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.

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.

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.

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.

Risk factors for hypothyroidism and thyroid hormone replacement after hemithyroidectomy in papillary thyroid carcinoma.

PURPOSE: Thyroid lobectomy is now preferred over total thyroidectomy to preserve thyroid function and reduce complications in patients with low-risk papillary thyroid carcinoma (PTC). One inevitable consequence of thyroidectomy includes hypothyroidism. This study aimed to evaluate the risk factors for hypothyroidism and thyroid hormone replacement after hemithyroidectomy in patients with PTC. METHODS: We retrospectively studied 353 patients with PTC who underwent hemithyroidectomy with or without central neck dissection from January 2012 to January 2019. We excluded patients who had hypo- or hyperthyroidism preoperatively and those who underwent total or subtotal thyroidectomy. We analyzed various risk factors related to postoperative hypothyroidism and thyroid hormone supplementation. RESULTS: Of the patients, 54.7% showed hypothyroidism after hemithyroidectomy (n=193 with n=157, subclinical hypothyroidism; n=36, overt hypothyroidism). Ninety-one percent of postoperative hypothyroidism cases developed within 7 months postoperatively. Eventually, 43.1% (n=152) of patients received levothyroxine after hemithyroidectomy. Preoperative high thyroid-stimulating hormone (TSH) level and low free thyroxine (fT4) level were significantly associated with postoperative hypothyroidism and the need for thyroid hormone supplementation postoperatively. CONCLUSION: Preoperative TSH and fT4 levels are predictive risk factors of hypothyroidism and need for supplementation of levothyroxine after hemithyroidectomy in patients with PTC. Finally, approximately 43% of patients need levothyroxine supplementation after hemithyroidectomy, and individual preoperative counseling is necessary for these patients.

Comparison of core-needle biopsy and repeat fine-needle aspiration for thyroid nodules with inconclusive initial cytology.

PURPOSE: We aimed to compare the efficacy of ultrasound-guided core-needle biopsy (CNB) with repeat fine-needle aspiration (rFNA) cytology in thyroid nodules with inconclusive results in initial fine-needle aspiration cytology. METHODS: We studied 402 patients who required a repeat biopsy of thyroid nodules using ultrasound-guided CNB (n = 192) or rFNA (n = 210) because of inconclusive results in initial FNA, corresponding to categories I, III, and IV of the Bethesda System for Reporting Thyroid Cytopathology. If repeat biopsy results were benign (category II), suspicious malignancy (category V), or malignancy (category VI), they were defined as "diagnostic results". The diagnostic yield and performances of repeat biopsy were analyzed and compared between the rFNA and CNB groups. RESULTS: The diagnostic results were obtained significantly higher in the CNB group than in the rFNA group (72.4% vs. 52.4%; P < 0.001). In the subgroup analysis, the diagnostic results were significantly higher in the CNB group than in the rFNA group for patients of categories I and III (P < 0.001 in both) in initial FNA. However, in patients with category IV nodules, there were no significant differences in diagnostic results between the two groups (P = 0.46). CONCLUSION: Compared to rFNA, ultrasound-guided CNB is useful and effective as a repeat biopsy option for thyroid nodules with non-diagnostic results (category I) and atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS) (category III) in initial FNA.

Comparison of postoperative cosmesis in transaxillary, postauricular facelift, and conventional transcervical thyroidectomy.

BACKGROUND: The most important advantage of remote-access robotic and endoscopic thyroidectomies is believed to be the excellent postoperative cosmesis. The purpose of this study was to compare directly the postoperative cosmetic outcomes of robotic/endoscopic thyroidectomy via gasless transaxillary and postauricular facelift approaches with those of conventional thyroidectomy. METHODS: We prospectively studied 100 patients who underwent robotic/endoscopic thyroidectomy using a gasless unilateral axillary (GUA) approach (50 patients) or a postauricular facelift approach (50 patients), and 50 who underwent conventional transcervical thyroidectomy. Postoperative cosmetic satisfaction scores and scar consciousness scores were evaluated at 3 months and 1 year after surgery using questionnaires developed by us. Vancouver scar scales were evaluated at the same time. The cosmetic satisfaction score was defined as the sum of the two cosmetic satisfaction questions with a rating scale of 1-5 each. The scar consciousness score was defined as the sum of the four scar consciousness questions with a rating scale of 0-3 each. RESULTS: The cosmetic satisfaction and scar consciousness scores were significantly lower (corresponding to greater satisfaction) in the transaxillary and postauricular facelift groups than the conventional group at 3 months and 1 year postoperatively. They did not differ between the transaxillary and postauricular facelift groups. However, the Vancouver scar scale score of the conventional group was significantly lower than those of the transaxillary and postauricular facelift groups (P < 0.001 in both). CONCLUSION: Robotic/endoscopic thyroidectomy via transaxillary or postauricular facelift approaches results in better cosmesis than the conventional approach. However, scar healing itself is worse in the transaxillary and facelift approaches than the conventional approach.

Efficacy of prophylactic central neck dissection in hemithyroidectomy for papillary thyroid carcinoma.

PURPOSE: To evaluate the efficacy of prophylactic central neck dissection (pCND) in hemithyroidectomy for clinically node-negative papillary thyroid carcinoma (PTC). METHODS: We retrospectively analyzed 299 patients who underwent thyroid lobectomy with or without pCND for unilateral PTC. Of the 299 patients, 245 (81.9%) underwent unilateral pCND along with lobectomy, and 54 (18.1%) patients underwent lobectomy without pCND. Propensity score matching was performed for five covariates to reduce selection bias. RESULTS: In the baseline cohort of 299 patients, mean age, extrathyroidal extension, T classification and stage were higher in the cases undergoing pCND than in those not undergoing pCND. After propensity score matching, the significant differences between the two groups seen in the baseline cohort disappeared. Recurrence rates and recurrence-free survival curves did not differ between the 2 matched groups each of 54 patients. CONCLUSION: The value of pCND in hemithyroidectomy for PTC is limited.

Nephrolithiasis predicts ischemic stroke: A longitudinal follow-up study using a national sample cohort.

This study sought to evaluate associations between nephrolithiasis and hemorrhagic and ischemic stroke using a national sample cohort from Korea. Data from 2002 to 2013 were collected for individuals ≥ 20 years of age in the Korean National Health Insurance Service (NHIS)-National Sample Cohort. We extracted nephrolithiasis patients (n = 22,636) and 1:4 matched controls (n = 90,544) and analyzed the occurrence of stroke. Matching was performed based on age, sex, income, region of residence, hypertension, diabetes mellitus, and dyslipidemia history. Crude and adjusted hazard ratios (HRs) were calculated using Cox proportional hazard models, and 95% confidence intervals (CIs) were determined. We performed subgroup analyses according to age, sex, and follow-up period. The adjusted HR of ischemic stroke was 1.13 (95% CI = 1.06-1.21) in the nephrolithiasis group (P < 0.001). The relationship between nephrolithiasis and ischemic stroke remained present for the young women and middle-aged men as well as during a follow-up period of ≤ 1 year. The HR for hemorrhagic stroke did not reach statistical significance. The risk of ischemic stroke was higher in the nephrolithiasis patients.

Efficacy of hemithyroidectomy in papillary thyroid carcinoma with minimal extrathyroidal extension.

PURPOSE: This study aimed to compare the oncologic outcomes of hemithyroidectomy with total thyroidectomy in clinically node-negative (cN0) papillary thyroid carcinoma (PTC) with minimal extrathyroidal extension (ETE). METHODS: Among 1826 PTC patients who underwent thyroidectomy from Jan 2001 to Dec 2014, there were 255 with unilateral cN0 PTC with minimal ETE and of equal to or less than 2 cm in size; these 255 patients were included in this study. We excluded patients who had tumor size > 2 cm, bilateral tumors, clinically positive nodes, maximal or no ETE, gross invasion of sternothyroid muscle, recurrent cancers or distant metastases. Total thyroidectomy was performed in 173 of the 255 patients, and hemithyroidectomy in 82 of them. A propensity score-matched analysis was carried out to reduce selection bias, with the following covariates: sex, age, tumor size, multiplicity and central neck dissection. RESULTS: In the baseline data of the 255 patients, female, age and tumor size were significantly higher in the total thyroidectomy group as was Stage III, whereas T and N classification did not differ in the two groups. Propensity score matching generated two matched groups of 66 patients each, in which the significant differences between the two groups seen in the baseline analysis disappeared. In the matched samples, recurrence rate (3.0% vs. 1.5%, p = 1.0) and recurrence-free survival curves did not differ between total thyroidectomy and hemithyroidectomy. CONCLUSIONS: Hemithyroidectomy can be recommended for cN0 PTC 1 cm or less with minimal ETE. Also it can be considered for cN0 PTC 11-20 mm with minimal ETE.

Long-term functional voice outcomes after thyroidectomy, and effect of endotracheal intubation on voice.

PURPOSE: The aim of this study was to evaluate long-term functional voice outcomes after thyroidectomy, and the effect of endotracheal intubation on post-operative voice impairment. METHODS: We prospectively analyzed the voice outcomes of 155 serial thyroidectomy patients for up to 2 years. The control group consisted of 69 patients who underwent parotidectomy. Patients with post-operative recurrent laryngeal nerve palsy or palsy of the external branch of the superior laryngeal nerve were excluded. Self-assessment voice symptom scores (VSS) by questionnaire, and objective acoustic parameters and maximum phonation times, were evaluated pre-operatively and 1 day, 3 days, 1 week, 1 month, 3, 6, 12, 18, and 24 months after surgery. RESULTS: VSS increased from day 1 after surgery in both groups, and returned to pre-operative levels by 24 months in the thyroidectomy group and after 1 week post-operatively in the parotidectomy (control) group. The post-operative VSS of the thyroidectomy group was significantly higher than that of the control group up to 12 months post-operatively. Highest frequency decreased immediately after surgery in the thyroidectomy group, and recovered to pre-operative levels by 12 and 18 months in females and males, respectively, whereas it recovered to pre-operative levels after the first week in the control group. CONCLUSION: Impairment of voice function may persist for more than 18 months after thyroidectomy even in patients without RLN palsy. Endotracheal intubation can affect voice outcomes adversely for 1 week post-operatively.

Low transverse incision for lateral neck dissection in patients with papillary thyroid cancer: improved cosmesis.

BACKGROUND: Various incisions and approaches have been developed for lateral neck dissection. The purpose of this study was to compare the surgical and cosmetic outcomes of a single low transverse incision with the hockey stick incision for lateral neck dissection (LND) in patients with papillary thyroid carcinoma (PTC). METHODS: We retrospectively analyzed 97 patients with PTC who underwent therapeutic LND and total thyroidectomy by low transverse incision (62 patients) or hockey stick incision (35 patients). We compared the operative results, cosmetic outcomes, objective scar measurement, and sensory disturbance between the two groups. RESULTS: The number of harvested and metastatic lymph nodes, Vancouver Scar Scale scores, and sensory change were not significantly different between the two groups. The mean number of harvested lymph nodes in level II was 9.82 vs. 9.63 (P = 0.885) (transverse incision vs. hockey stick incision, respectively) and in level V was 6.36 vs. 5.63 (P = 0.597). However, subjective satisfaction with the scar and neck contour was higher in the low transverse incision group compared with the hockey stick incision group. Scores for scar consciousness and sensory change were not significantly different between the two groups. CONCLUSIONS: A single low transverse incision may provide equivalent surgical outcomes and superior cosmetic outcomes compared with the hockey stick incision for LND in PTC.

Long-term functional outcomes after resection of tongue cancer: determining the optimal reconstruction method.

The appropriate tongue reconstruction method is critical for better functional outcomes. The aim of this study was to determine the optimal reconstructive method for restoring postoperative function based on the extent of resection. We retrospectively reviewed 43 patients with lateral oral tongue cancer who underwent glossectomy between January 2010 and October 2014. Tongue mobility, articulation, verbal diadochokinesis, speech intelligibility and swallowing outcomes were assessed 2-3 years postoperative and were analyzed according to resected tongue volume and the method of reconstruction. In partial glossectomy cases, the secondary intention group had better function in tongue mobility, articulation, and speech intelligibility (p < 0.001 for all) than the free flap reconstruction group. In contrast, in hemi-glossectomy cases, the free flap reconstruction group had better tongue mobility, articulation, verbal diadochokinesis and speech intelligibility (p < 0.05 for all) than the secondary intention group. There was no significant difference in swallowing outcome between the secondary intention and flap reconstruction groups in both partial glossectomy and hemi-glossectomy cases. In conclusion, secondary intention appears to be the most appropriate option after partial glossectomy. However, flap reconstruction is necessary to restore tongue volume and function in patients who undergo a resection of more than half of the tongue volume.

Oncologic outcomes of robotic thyroidectomy: 5-year experience with propensity score matching.

BACKGROUND: The oncologic outcome of robotic thyroidectomy is not yet well established. The aim of this study was to evaluate the recurrence rate after robotic thyroidectomy in comparison with conventional thyroidectomy for papillary thyroid carcinoma (PTC). METHODS: We analyzed 896 patients with PTC who either underwent robotic (212 patients using a gasless unilateral axillary or an axillo-breast approach) or conventional cervical thyroidectomy (684 patients) with/without central neck dissection between October 2008 and February 2014. We excluded patients who underwent concomitant lateral neck dissection or completion thyroidectomy, and cases with T4 tumor, tumor lager than 4 cm, other types of thyroid cancer, recurrent cancer, and distant metastasis. A propensity score matching analysis was done with ten covariates including age, gender, body mass index, tumor size, multifocality, bilaterality, extrathyroidal extension, type of thyroidectomy, extent of central neck dissection, and RAI ablation to reduce selection bias. RESULTS: In baseline data, the male ratio and the mean age were lower in the robotic group. Stage, multifocality, and bilaterality were higher in the conventional group. The rate of total thyroidectomy was higher in the conventional group. The two matched groups of each 185 patients were produced and well balanced by propensity score matching. In the comparison of propensity score matched groups, operative time was longer in the robotic group (P < 0.001), and postoperative complications did not differ between the two groups, except for transient hypoparathyroidism and formation of seroma. The recurrence rate did not differ between the two groups after a mean follow-up of 43.6 months (0.5 and 1.1 % in the robotic and conventional groups, respectively, P = 0.375). CONCLUSION: The oncologic outcome of robotic thyroidectomy in 5-year experience is comparable to that of conventional thyroidectomy in selected patients with PTC.

Long-Term Voice Outcomes After Robotic Thyroidectomy.

BACKGROUND: The purpose of this study was to evaluate the long-term voice function after robotic thyroidectomy in comparison with conventional transcervical thyroidectomy. METHODS: We prospectively evaluated the voice functions of 54 patients with thyroid nodules who underwent robotic thyroidectomy by a gasless unilateral axillary or axillo-breast approach and of 70 patients who underwent conventional thyroidectomy. Subjective voice symptom score (VSS) was evaluated in questionnaires before thyroidectomy and then at 3, 6, 12, and 24 months after surgery. Objective acoustic parameters analyzed during the same period included fundamental frequency, jitter, shimmer, noise-to-harmonic ratio, highest frequency, frequency and intensity range, and maximal phonation time. RESULTS: At 3 months after surgery, VSS was better in the robotic group than in the conventional group. At 2 years after surgery, VSS had recovered to the pre-operative level in the robotic group, whereas it remained significantly worse at 2 years in the conventional group. The phonatory frequency range and highest frequency were significantly wider and higher, respectively, in the robotic group than the conventional group at 6, 12, and 24 months postoperatively.Within the robotic group, the frequency range and highest frequency recovered to pre-operative levels by 6 months, whereas in the conventional group they remained below the pre-operative levels at 2 years post-operatively. There were no differences in other acoustic parameters between the two groups of patients at any period. CONCLUSION: Up to 2 years post-operatively, robotic thyroidectomy has advantages in terms of recovery of voice symptoms and acoustic parameters over conventional thyroidectomy.

Feasibility of Charcoal Tattooing for Localization of Metastatic Lymph Nodes in Robotic Selective Neck Dissection for Papillary Thyroid Carcinoma.

BACKGROUND: This study aimed to evaluate the feasibility and effectiveness of ultrasound-guided charcoal tattooing in locating metastatic lymph nodes in robotic selective neck dissection (SND) for papillary thyroid carcinoma (PTC). METHODS: The overall study group comprised 21 patients with PTC who underwent robotic SND via a unilateral transaxillary approach for treatment of suspicious lymph node metastasis in the lateral compartment. Charcoal suspension was injected into 10 of the patients (total of 23 lesions) 1 day before robotic SND. The authors evaluated the location of the tattoos, the success rate of localization, the intraoperative detection rate, and the complications associated with the procedure. The perioperative results were compared with those in the control group of 11 patients who did not receive charcoal tattooing. RESULTS: Charcoal suspension was successfully injected into 22 of the 23 suspicious lymph nodes (95.7 %). The remaining lesion was located posterior to the internal jugular vein. Therefore, the charcoal was injected into the soft tissue around the lymph node. Ultrasound-guided injections were well tolerated in all the patients, and no major complications occurred. All the charcoal-tattooed lesions were identified intraoperatively by the surgeon. The number of harvested and metastatic lymph nodes in the lateral compartment was greater in the patients with charcoal tattoo localization than in the control group. The two groups did not differ in terms of perioperative complications, operation time, or volume of drainage. CONCLUSION: Ultrasound-guided charcoal tattooing for localization of metastatic lymph nodes is feasible and effective in robotic SND for the treatment of PTC with lateral compartment lymph node metastasis.

Association between ADH1B and ADH1C polymorphisms and the risk of head and neck squamous cell carcinoma.

Alcohol consumption is one of the major risk factors for head and neck squamous cell carcinoma (HNSCC), and the alcohol dehydrogenase (ADH) family proteins are key enzymes in ethanol metabolism. We examined the associations between single nucleotide polymorphisms (SNPs) of ADH1B and ADH1C and the risk of HNSCC. We analyzed six SNPS of ADH1B, namely -992C > G, -957C > A, +3170A>G, +3377G>T, +3491G>A, and +13543A>G, and five SNPs of ADH1C, namely -1064C>T, -325G>C, +5702A>G, +7462T>C, and +13044A>G, in 260 Korean HNSCC patients and 330 controls, using single base extension and the TaqMan assay. The odds ratios (ORs) and 95 % confidence intervals (95 % CIs) of the CG and GG genotypes of ADH1B -992C>G, the AA genotype of -957C>A, the GG genotype of +3170A>G, the GA genotype of +3491G>A, and +13543A>G were 0.51 (0.32-0.82), 0.63 (0.42-0.94), 1.84 (1.13-2.99), 1.77 (1.15-2.73), 2.34 (1.44-3.79), and 2.21 (1.23-3.95), respectively. The ORs of ADH1C +13044A>G were 1.94 (1.01-3.71) and 1.97 (1.05-3.71) in the dominant and co-dominant models, respectively. The ORs of the GC genotype of ADH1C -325G>C and the AG genotype of +5702A>G were 2.52 (1.51-4.21) and 2.43 (1.36-4.32), respectively. ADH1B +3170A>G and ADH1C +13044A>G were in strong linkage disequilibrium with the other SNPs of ADH1B and ADH1C, respectively. There were gene-environment interactions between ADH1B +3170A>G and ADH1C +13044A>G and alcohol consumption and smoking. ADH1B +3170A>G and ADH1C +13044A>G SNPs are associated with an increased risk of HNSCC, and they could be used as biomarkers for the high-risk group of HNSCC in Koreans.