Unilateral Central Neck Dissection Research Articles

Hypoparathyroidism after Thyroidectomy and the Effect of Parathyroid Autotransplantation

Background and ObjectivesZZTo preserve the parathyroid gland during thyroidectomy, understanding of its anatomy and physiology is essential. Parathyroid autotransplantation can be performed to restore the function of parathyroid gland. However, the efficacy of parathyroid au totransplantation is still debatable. The aim of this study was to analyze the frequency of hypoparathyroidism following thyroidectomy and evaluate the efficacy of parathyroid autotransplan tation. Subjects and MethodZZWe analyzed 449 patients who underwent thyroidectomy from January 2006 to June 2010. A total of 419 patients underwent total thyroidectomy, while 30 patients underwent unilateral lobectomy. Among the total thyroidectomy group, 96 patients underwent unilateral central neck dissection and 186 patients underwent bilateral central neck dissection. We analyzed the frequency of hypoparathyroidism according to the extent of thyroidectomy and central neck dissection, and parathyroid gland autotransplantation. ResultsZZTransient hypoparathyroidism occurred in 20% of lobectomy patients and 54.6% of the entire thyroidectomy group. Permanent hypoparathyroidism occurred only in 7.2% of the entire thyroidectomy group. Transient and permanent hypoparathyroidism occurred in 47.4% and 6.5%, respectively, of the patients without central neck dissection, in 54.0% and 7.3%, respectively, of the patients with unilateral central neck dissection, and 60.2% and 7.5%, respectively, of the patients with bilateral central neck dissection. Parathyroid autotransplantation was performed in 29 patients of 105 patients whose one or more parathyroid glands were removed inadvertently, and permanent hypoparathyroidism did not occur among those patients. ConclusionZZThe frequency of transient hypoparathyroidism was increased according to the extent of thyroidectomy and central neck dissection. Parathyroid autotransplantation might be effective in minimizing permanent hypoparathyroidism. � Korean J Otorhinolaryngol-Head Neck Surg 2013;56:28-33 Key WordsZZCentral neck dissection ㆍHypoparathyroidism ㆍParathyroid Key WordsZZautotransplantation ㆍThyroidectomy.

Factors affecting the adequacy of lymph node yield in prophylactic unilateral central neck dissection for papillary thyroid carcinoma

Determinants for adequate lymph node yield (LNY) in prophylactic central neck dissection (pCND) for papillary thyroid carcinoma (PTC) remain unclear. We aimed to determine factors affecting LNY in pCND. Of 230 patients, 109 (47.4%) had total thyroidectomy and unilateral pCND. A specimen of ≥ 6 central lymph nodes (CLNs) was considered adequate. Factors such as patient clinicopathologic features, specimen dimensions, and pathologists' experience were compared between those with LNY < 6 (n = 52) and LNY ≥ 6 (n = 57). A multivariate analysis was conducted to identify independent factors for LNY ≥ 6. Age, sex, presentation, body mass index, tumor characteristics, TNM stages, MACIS score, and pathologist's experience were not significant determinants for LNY ≥ 6. In the univariate analysis, the length (P = 0.021), width (P = 0.047), thickness (P = 0.024), and pN1a (P = 0.042) were significant determinants but in the multivariate analysis, the length (OR = 1.486 (95% CI: 1.053-2.097), P = 0.024) was the only independent factor for LNY ≥ 6. Postoperative vocal cord palsy, hypoparathyroidism, stimulated thyroglobulin and recurrences were similar between LNY <6 and ≥ 6. Length (or the longest measured dimension) of the fresh CLN specimen was the only factor assuring LNY ≥ 6. Surgical complications and short-term outcomes appeared similar between LNY <6 or ≥ 6.

Significance of Metastatic Lymph Node Ratio on Stimulated Thyroglobulin Levels in Papillary Thyroid Carcinoma after Prophylactic Unilateral Central Neck Dissection

Background Prognostic significance of metastatic central lymph node ratio (CLNR) in papillary thyroid carcinoma (PTC) remains unknown. Because postsurgical detectable stimulated thyroglobulin (DsTg) after radioiodine ablation may imply persistent or recurrent disease, we evaluated the association between CLNR and rate of DsTg in patients with PTC who underwent unilateral prophylactic central neck dissection.

Impact of Routine Unilateral Central Neck Dissection on Preablative and Postablative Stimulated Thyroglobulin Levels after Total Thyroidectomy in Papillary Thyroid Carcinoma

Background. Prophylactic central neck dissection (CND) remains controversial in papillary thyroid carcinoma (PTC). Because postsurgical stimulated thyroglobulin (sTg) level is a good surrogate for recurrence, the study aimed to evaluate the impact of prophylactic CND on preablative and postablative sTg levels after total thyroidectomy. Methods. Of the 185 patients retrospectively analyzed, 82 (44.3%) underwent a total thyroidectomy and prophylactic CND (CND-positive group) while 103 (55.7%) underwent total thyroidectomy only (CND-negative group). All patients had no preoperative or intraoperative evidence of lymph node metastases. Clinicopathological characteristics, postoperative outcomes, and preablative and postablative sTg levels were compared between the two groups. Preablative sTg level was taken at the time of radioiodine ablation, while postablative sTg level was taken 6 months after ablation. A multivariable analysis was conducted to identify factors for preablative athyroglobulinemia (sTg 0.5 lg/L). Results. Relative to the CND-negative group, the CNDpositive group had larger tumors (15 mm vs. 10 mm, P 0.005), more extrathyroidal extension (26.8% vs. 14.6%, P 0.003), more tumor, node, metastasis system stage III disease (32.9% vs. 9.7%, P 0.001), and more temporary hypoparathyroidism (18.3% vs. 8.7%, P = 0.017). Fourteen patients (17.1%) in the CND-positive group were upstaged from stages I/II to III as a result of prophylactic CND. The CND-positive group experienced lower median preablative sTg (\0.5 lg/L vs. 6.7 lg/L, P 0.001) and a higher rate of preablative athyroglobulinemia (51.2% vs. 22.3%, P = 0.024), but these differences were not observed 6 months after ablation. Prophylactic CND was the only independent factor for preablative athyroglobulinemia. Conclusions. Although performing prophylactic CND in total thyroidectomy may offer a more complete initial tumor resection than total thyroidectomy alone by minimizing any residual microscopic disease, such a difference becomes less noticeable 6 months after ablation.

Significance of Size of Lymph Node Metastasis on Postsurgical Stimulated Thyroglobulin Levels After Prophylactic Unilateral Central Neck Dissection in Papillary Thyroid Carcinoma

BackgroundThe prognostic significance of size of central lymph node metastasis (CLNM) in papillary thyroid carcinoma (PTC) remains unknown. Because postsurgical detectable stimulated thyroglobulin (DsTg) after radioiodine ablation may imply persistent or recurrent disease, we evaluated the association between size of CLNM and rate of DsTg in patients with PTC who underwent unilateral prophylactic central neck dissection.MethodsTo be eligible for analysis, the prophylactic central neck dissection specimen with <3 central lymph nodes (CLNs) or size of CLNM ≥1 cm as measured under the microscope was excluded. Of 132 specimens, 89 (67.4 %) were eligible. Forty patients (44.9 %) had no metastasis or pN0, 20 (22.5 %) had micrometastasis (<2 mm) or pN1mic and 29 (32.6 %) had macrometastasis (≥2 mm) or pN1mac. Postablation sTg level was measured 9 months after surgery. A multivariable analysis was conducted to identify independent factors for postablation DsTg.ResultsLarger-sized CLNM correlated significantly with younger age (p = 0.028), greater number of CLN retrieved (p = 0.016), greater number of metastatic CLN excised (p < 0.001), higher metastatic CLN ratio (p = 0.006) and postablation sTg level (p = 0.012). In the multivariable analysis, after adjusting for tumor size and metastatic CLN ratio, size of CLNM was an independent predictor of postablation DsTg (odds ratio 1.56, 95 % confidence interval 1.09–2.24, p = 0.015). Relative to pN0, the odds ratios for postablation DsTg in pN1mic and pN1mac were 2.53 (95 % confidence interval 0.35–19.00, p = 0.351) and 5.81 (95 % confidence interval 1.22–27.70, p = 0.027), respectively.ConclusionsSize of CLNM was an independent factor for DsTg 9 months after surgery. Patients with pN1mac were almost 6 times more likely to have postablation DsTg than those with pN0 or pN1mic.

Significance of Metastatic Lymph Node Ratio on Stimulated Thyroglobulin Levels in Papillary Thyroid Carcinoma after Prophylactic Unilateral Central Neck Dissection

BackgroundPrognostic significance of metastatic central lymph node ratio (CLNR) in papillary thyroid carcinoma (PTC) remains unknown. Because postsurgical detectable stimulated thyroglobulin (DsTg) after radioiodine ablation may imply persistent or recurrent disease, we evaluated the association between CLNR and rate of DsTg in patients with PTC who underwent unilateral prophylactic central neck dissection.MethodsTo be eligible for analysis, the prophylactic central neck dissection specimen had to contain ≥3 central lymph nodes (CLNs) with ≥1 harboring metastasis. Of 129 specimens, 51 (39.5%) were eligible. CLNR was calculated as follows: (number of metastatic CLNs/number of CLNs retrieved) × 100. They were categorized into group 1 (CLNR <33.34%) (n = 14), group 2 (CLNR 33.34–66.67%) (n = 15), and group 3 (CLNR >66.67%) (n = 22). Postablation sTg level was measured 6 months after radioiodine ablation. A multivariate analysis was conducted to identify factors for postablation DsTg.ResultsYoung age, palpable neck swelling, large tumor size, advanced tumor, node, metastasis system (TNM) stage, and large number of metastatic CLNs were significantly associated with high CLNR (P < 0.05). Compared to groups 1 and 2, group 3 had significantly higher DsTg rate (P = 0.018). Those who developed subsequent recurrence had significantly higher DsTg rate than those who did not (100% vs. 39.1%, P = 0.013). In the multivariate analysis for postablative DsTg, after adjusting for age, palpable neck swelling, tumor size, TNM stage, and number of metastatic CLNs, CLNR was the only independent factor (odds ratio 1.15, 95% confidence interval 1.01–1.31, P = 0.036).ConclusionsA higher CLNR was associated with a higher rate of postablative DsTg; this may imply higher future recurrence rate.

Impact of Combined Prophylactic Unilateral Central Neck Dissection and Hemithyroidectomy in Patients with Papillary Thyroid Microcarcinoma

Lymph node metastases occur frequently in patients with papillary thyroid carcinoma (PTC), and the central compartment of the neck is the most frequently involved site. Some authors advocate prophylactic central neck dissection (CND) during total thyroidectomy. However, little is known about the effects of prophylactic unilateral CND in papillary thyroid microcarcinoma (PTMC) patients who undergo hemithyroidectomy. This study was designed to investigate the impact of prophylactic unilateral CND in this population. The clinical records of 152 patients with a PTMC ≤1 cm according to preoperative ultrasonography who underwent hemithyroidectomy between 2002 and 2009 were assessed retrospectively. Outcomes were compared between the 65 (43%) patients who underwent hemithyroidectomy with elective unilateral CND (CND+ group) and the 87 (57%) patients who underwent hemithyroidectomy only (CND- group). In the CND- group, 37 patients (43%) had microscopic extrathyroidal extension (ETE). In the CND+ group, 33 patients (50.7%) had ETEs or nodal metastases. During follow-up, recurrence was observed in 14 patients (n = 1, CND+ group; n = 13, CND- group). Prophylactic unilateral CND was associated with a significantly lower rate of locoregional recurrence (P = 0.017). Compared with hemithyroidectomy alone, prophylactic unilateral CND may decrease the rate of locoregional recurrence in patients with PTMC.

Impact of Routine Unilateral Central Neck Dissection on Preablative and Postablative Stimulated Thyroglobulin Levels after Total Thyroidectomy in Papillary Thyroid Carcinoma

BackgroundProphylactic central neck dissection (CND) remains controversial in papillary thyroid carcinoma (PTC). Because postsurgical stimulated thyroglobulin (sTg) level is a good surrogate for recurrence, the study aimed to evaluate the impact of prophylactic CND on preablative and postablative sTg levels after total thyroidectomy.MethodsOf the 185 patients retrospectively analyzed, 82 (44.3%) underwent a total thyroidectomy and prophylactic CND (CND-positive group) while 103 (55.7%) underwent total thyroidectomy only (CND-negative group). All patients had no preoperative or intraoperative evidence of lymph node metastases. Clinicopathological characteristics, postoperative outcomes, and preablative and postablative sTg levels were compared between the two groups. Preablative sTg level was taken at the time of radioiodine ablation, while postablative sTg level was taken 6 months after ablation. A multivariable analysis was conducted to identify factors for preablative athyroglobulinemia (sTg < 0.5 μg/L).ResultsRelative to the CND-negative group, the CND-positive group had larger tumors (15 mm vs. 10 mm, P < 0.005), more extrathyroidal extension (26.8% vs. 14.6%, P < 0.003), more tumor, node, metastasis system stage III disease (32.9% vs. 9.7%, P < 0.001), and more temporary hypoparathyroidism (18.3% vs. 8.7%, P = 0.017). Fourteen patients (17.1%) in the CND-positive group were upstaged from stages I/II to III as a result of prophylactic CND. The CND-positive group experienced lower median preablative sTg (<0.5 μg/L vs. 6.7 μg/L, P < 0.001) and a higher rate of preablative athyroglobulinemia (51.2% vs. 22.3%, P = 0.024), but these differences were not observed 6 months after ablation. Prophylactic CND was the only independent factor for preablative athyroglobulinemia.ConclusionsAlthough performing prophylactic CND in total thyroidectomy may offer a more complete initial tumor resection than total thyroidectomy alone by minimizing any residual microscopic disease, such a difference becomes less noticeable 6 months after ablation.

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To retrospectively analyze the outcomes of patients treated with isthmusectomy for a solitary papillary thyroid carcinoma (PTC) confined to the isthmus, and re-assess the role of isthmusectomy in these patients.The medical records of 65 patients who underwent isthmusectomy for a solitary PTC confined to the isthmus at the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences, Peking Union Medical College between 1985 and 2015 were retrospectively reviewed. Demographic data, surgical procedures, pathological characteristics, stages, and outcomes were analyzed.Patients’ median age was 39 years (range, 19–63), and the majority were female (86.2% female, 13.8% male). All patients had a solitary PTC confined to the isthmus and were treated with isthmusectomy. Pretracheal lymph node dissection was performed in 34 patients, in which unilateral central neck dissection was performed in 4 patients and bilateral central neck dissection in 2 patients. Microscopic extrathyroidal extension (ETE) was observed in 23 (35.4%) patients, and macroscopic ETE was observed in 3 (4.6%) patients. Thirty-eight (58.5%) patients were stage pT1a, 19 (29.2%) patients were stage pT1b, 5 (7.7%) patients were stage pT2, and 3 (4.6%) patients were stage p3b. Fifteen (23.1%) patients were stage pN1a. Median follow-up time was 78 months (range, 12–274). Two patients experienced a recurrence and both achieved remission after re-operation. The 10-year recurrence-free survival was 92.1%. The 10-year overall survival and disease specific survival were 98.3% and 100%, respectively.Isthmusectomy is effective and sufficient for select patients with a solitary PTC confined to the isthmus.