The effect of lateral neck dissection on complication rate for total thyroidectomy

Intraoperative neuromonitoring during thyroidectomy does not decrease vocal cord palsy risk, but the cumulative experience of the surgeon may

PURPOSE

To evaluate the influence of intraoperative neuromonitoring (IONM) on vocal cord palsy (VCP) rates and assess the temporal trends in VCP rates.

METHODS

The subjects of this retrospective study were patients who underwent thyroidectomy for thyroid cancer between March, 2014 and June, 2022, at a university hospital in Korea. We compared VCP rates between the non-IONM and IONM groups and analyzed the risk factors for VCP and VCP rates over time.

RESULTS

A total of 712 patients were included in the analysis. The rates of transient and permanent VCP did not differ significantly between the non-IONM and IONM groups. Transient VCP occurred in 4.6% and 4.3% patients (p = 0.878) and VCP was permanent in 0.7% and 0.4% patients (p = 0.607) in the non-IONM and IONM groups, respectively. Among the nerves at risk, transient damage occurred in 2.8% and 3.0% patients (p = 0.901), and permanent damage occurred in 0.4% and 0.3% (p = 0.688), respectively. Multivariate analysis revealed no significant risk factors for VCP. There was a significant decreasing trend in VCP rates over time as the cumulative number of cases increased (p = 0.017).

CONCLUSIONS

IONM did not reduce the risk of VCP significantly. However, the declining trend of VCP rates suggests that the surgeon's experience may mitigate VCP risk.

Safety and surgical outcomes of single-port trans-axillary robot-assisted thyroidectomy: Experience from a consecutive series of 300 patients

Since the introduction of the single-port (SP) robotic system, SP trans-axillary robot-assisted thyroidectomy (SP-TART) has been performed. We aimed to evaluate the safety and surgical outcomes of SP-TART in a consecutive series of 300 cases. We analyzed 300 patients with thyroid disease who underwent SP-TART from October 2021 to May 2023 in St. Mary's Hospital in Seoul, Korea. We analyzed the patients' clinicopathological characteristics and perioperative outcomes according to surgical extent. Of the 300 cases analyzed, 250 patients underwent less than total thyroidectomy (LTT), 31 patients underwent total thyroidectomy (TT), and 19 patients underwent TT with modified radical neck dissection (TT c mRND). The mean operative times for LTT, TT, and for TT c mRND were 69.8 ± 23.6, 104.2 ± 30.7, and 223.7 ± 72.4 min, respectively. Complications, including postoperative bleeding, transient hypoparathyroidism, and vocal cord palsy, were observed in nine, six, and six LTT, TT, and TT c mRND cases. The SP-TART method is a safe and feasible surgical option with a short operative time, good surgical outcome, and excellent cosmetic results.

Factors Associated With Injury to Recurrent Laryngeal Nerve in Patients Undergoing Surgery for Thyroid Cancer: A Single-centre Study Using Translaryngeal Ultrasound

AIMS

Intraoperative injury to the recurrent laryngeal nerve (RLN) is a serious complication occurring more frequently in patients with thyroid cancer than in those with benign thyroid diseases. However, data on the risk factors for RLN injury among patients with thyroid cancer are scarce. Currently, RLN injury is diagnosed by laryngoscopy, but translaryngealultrasonography (TLUS), which is less invasive, appears to have a similar accuracy. Herein, we analysed risk factors ofintraoperative RLN injury in patients with thyroid cancer and assessed the diagnostic performance of TLUS.

PATIENTS AND METHODS

In this prospective study, we enrolled patients undergoing surgery for thyroid cancer from October 2020 to October 2021. Medical and surgical variables were analysed as risk factors of RLN injury. TLUS was compared with laryngoscopy in diagnosing RLN injury.

RESULTS

There were 185 patients who underwent 196 surgeries. Of all surgeries, 23 (11.7%) caused RLN injury ascertained on laryngoscopy. Compared with laryngoscopy, TLUS displayed high sensitivity (97.7%; 95%CI: 94.3%-99.4%) and specificity (100%; 95% CI: 82.4%-100%). Before surgery, medical and surgical characteristics did not differ significantly between patients with or without RLN injury, but RLN entrapment by tumour was more frequent in those with the injury (P < 0.001). The risk of RLN injury was increased in patients undergoing thyroidectomy with lateral neck dissection (OR = 4.53; 95% CI: 1.29-14.32) and in those with lymph node metastases (OR = 2.76; 95% CI: 1.03-7.01).

CONCLUSION

Intraoperative RLN injury in patients with thyroid cancer is more common after operations requiringgreater resections and with lymph node involvement. TLUS could be used to diagnose RLN injury.

An effective method to reduce lymphatic drainage post-lateral cervical lymph node dissection of differentiated thyroid cancer: a retrospective analysis

Background

Lymph or chyle leak (LL/CL) is severe complications after lateral cervical lymph node dissection (LLND), mainly due to iatrogenic injury of the lymphatic duct. Efficient and well-operated methods to reduce postoperative drainage are still lacking. This was a feasibility study to evaluate a new method of preventing LL/CL compared to conventional treatment.

Method

We retrospectively analyzed 20 consecutive patients who used the “pedicled omohyoid flap covering (POFC)” method during LLND from January 2019 to December 2021 in our center as an observation group. Another 20 consecutive patients used the conventional method during LLND in this period as a control group. The clinical and pathological features of the two groups were compared, and the related factors that affected postoperative lymphatic drainage were analyzed with Cox proportional hazards models.

Results

The drainage volume per 24 h and the incidence of LL/CL in the control group were both higher than that in the observation group (all P < 0.05), and the number of lymph nodes dissected in the IV region > 10 and the use of the POFC method were the independent risk factors that significantly affected the incidence of LL/CL post LLND (all P < 0.05).

Conclusions

POFC is a safe and useful method for reducing drainage and preventing LL/CL post-LLND, especially for patients with heavy metastasis of the lymph nodes in the IV region.

Ultrasonography-Guided Thermal Ablation for Cervical Lymph Node Metastasis of Recurrent Papillary Thyroid Carcinoma: Is it Superior to Surgical Resection?

AIM

The study aimed to systematically evaluate the safety and efficacy of ultrasonography-guided percutaneous thermal ablation in the treatment of cervical lymph node metastasis (LNM) of recurrent papillary thyroid carcinoma (PTC).

METHODS

PubMed, PubMed Central (PMC), Embase, and Cochrane were examined. The inclusion and exclusion criteria were determined and the relevant data were extracted from the library and other databases for LNM thermal ablation of recurrent PTC. The data were analyzed using Stata15.1, Revman5.3 software, and the standard errors of 95% confidence intervals were estimated using fixed or random effects models. Volume reduction rate (VRR), Serum thyroglobulin (Tg) level before and after thermal ablation, the total complications and major complications incidence were analyzed.

RESULTS

A total of 18 literature articles were included, namely, 10 radiofrequency ablation (RFA), 4 laser ablation (LA), and 4 microwave ablation (MWA). A total of 321 patients had 498 LNM. LNM volume changes before and at the last follow-up of thermal ablation (SMD = 1.04, I² = 8%, 95% CI 0.86-1.21, P <0.0001). The postoperative lymph node VRR was 88.4% (95% CI 77.8-97.3%, I² = 34%, P = 0.14). Tg measurements before and after thermal ablation (SMD = 1.15, 95% CI 0.69-1.60, I² = 84%, P <0.0001). The incidence of total complications was 5.0% (95% CI 3.0-7.0%, I² = 0.0%, P = 0.915), and the incidence of major complications was 4.0% (95% CI 2.0-6.0%, I² = 0.0%, P = 0.888). A total of 131 LNM were located in the central region, and the major complication rate was 12.0% (95% CI 6.0-18.0%, I² = 0.0%, P = 0.653).

CONCLUSION

Ultrasonography-guided thermal ablation is safe and effective in the treatment of LNM of recurrent PTC. The ablation strategy of central LNM needs to be further explored and improved. It can be used as an alternative to surgery for patients with high surgical risk or who refuse resurgery.

SYSTEMATIC REVIEW REGISTRATION

10.37766/inplasy2022.6.0004, identifier INPLASY202260004.

Ultrasound-guided thermal ablation for cervical lymph node metastasis from thyroid carcinoma: a meta-analysis of clinical efficacy and safety

To evaluate the efficacy and safety of thermal ablation (radiofrequency, microwave, and laser) for treating lymph node metastasis from papillary thyroid carcinoma. A literature search was performed in the Medline, Embase, and Cochrane Library databases. Thirteen studies focusing on the efficacy and safety of thermal ablation for treating lymph node metastasis were eligible. The assessed outcomes were primarily pooled using a random- or fixed-effects model based on the results of the heterogeneity test. A total of 235 patients with 445 metastatic lymph nodes were included. Laser, microwave, and radiofrequency ablation all showed a significant reduction in maximum diameter and volume of metastatic lymph nodes (P < 0.0001). Microwave ablation had a higher volume reduction rate (99%; 95% CI, 98-100%) comparing to the other two techniques (P = 0.0057). For all ablations, the pooled completely disappear rate was 70% (95% CI, 45-87%) and the recurrent rate was 3% (95% CI, 2-5%). Thyroglobulin levels significantly decreased (P < 0.0001). No major complications were encountered; the pooled proportion of voice change was low to 4% (95% CI, 2-7%). Thermal ablation is acceptable treatments to manage lymph nodes metastasis from papillary thyroid carcinoma in terms of efficacy and safety for non-surgical candidates.

Optimal surgeon-volume threshold for neck dissections in the setting of primary thyroid malignancies

BACKGROUND

Although the surgeon-volume relationship is well documented for thyroidectomy, less is known about central neck and lateral neck dissections. The aim of this study was to evaluate and determine the surgeon-volume threshold for central neck and lateral neck dissections for thyroid cancer.

METHODS

A retrospective analysis of patients with thyroid malignancies who received a central or lateral neck dissection in the New York Statewide Planning and Research Cooperative System was performed (2007-2017). Demographic variables included age, sex, race, and a Charlson Comorbidity Score. Thirty-day complications were identified using International Classification of Diseases (ICD) codes for central neck, lateral neck, and other surgical complications. Optimal surgeon-volume threshold was estimated using a change-point logistic regression. Using the identified threshold, surgeons were then classified to low versus high volume surgeons. Logistic regression analysis was conducted to examine the effect of high-volume status on outcomes.

RESULTS

In total, 3,808 patients who underwent neck dissections (3,485 central neck dissections and 977 lateral neck dissections) were analyzed. Surgeon-volume threshold to distinguish high volume surgeons for central neck dissections and lateral neck dissections was 7.0 (95% bootstrap confidence interval 1.3-7.5) and 3.3 (1.2-4.8) neck dissections/year, respectively. For central neck dissection, high volume surgeons were associated with a lower rate of vocal cord paralysis (odds ratio 0.45 [0.24-0.82]), hypocalcemia (0.31 [0.14-0.65]), and all-cause complications (0.42 [0.29-0.59]). For lateral neck dissection, high volume surgeons were associated with a lower odds all-cause complications (0.42 [0.23-0.74]) but not lateral neck specific complications (0.18 [0.01-1.07]).

CONCLUSION

A threshold of 7.0 central neck dissections and 3.3 lateral neck dissections for thyroid cancer per year improves outcomes. Guidelines for training and centralization of care can be guided by these results to reduce complications.

Surgical Skills and Technological Advancements to Avoid Complications in Lateral Neck Dissection for Differentiated Thyroid Cancer

Neck dissection is a surgical procedure reserved for thyroid cancer cases with clinically evident lymphatic invasion. Although neck dissection is a reliable and safe procedure, it can determine a significant morbidity involving a variety of structures of nervous, vascular and endocrine typology. A careful pre-operative study is therefore essential to better plan surgery. Surgical experience, combined with accurate surgical preparation and merged with adequate and specific techniques, can certainly help reduce the percentage of complications. In recent years, however, technology has also proved to be useful. Its crucial role was already recognized in the safeguard of the integrity of the laryngeal nerve through neuro-monitoring, but new technologies are emerging to help the preservation also of the parathyroid glands and other structures, such as the thoracic duct. These surgical skills combined with the latest technological advancements, that allow us to reduce the incidence of complications after neck dissection for thyroid cancer, will be reported in the present article. This topic is of significant interest for the endocrine and metabolic surgeons' community.

Efficacy and Safety of Thermal Ablation for Treatment of Solitary T1N0M0 Papillary Thyroid Carcinoma: A Multicenter Retrospective Study

Background Microwave ablation (MWA) and radiofrequency ablation (RFA) have recently attracted interest as minimally invasive treatment modalities for papillary thyroid carcinoma (PTC). However, the ablation outcomes of T1N0M0 PTC are not well characterized. Purpose To evaluate the efficacy and safety of thermal ablation (MWA or RFA) of solitary T1N0M0 PTC in patients who were ineligible for (due to presence of comorbid cardiovascular disease, renal failure, other malignancy, etc) or who refused surgery. Materials and Methods This was a retrospective multicenter study of 847 patients (660 women) who underwent thermal ablation for PTC (673 T1a, 174 T1b) between March 2015 and March 2020; of these patients, 645 underwent MWA and 202 underwent RFA. The mean age of patients was 46 years ± 11 (standard deviation) (age range, 18-81 years); the mean follow-up time was 22 months ± 13 (range, 6-60 months). Changes in tumor size and volume and the rates of technical success, tumor disappearance, disease progression, and complications were assessed. Results The technical success rate was 100%. Relative to preablation measurements, the maximum diameter and volume of the ablation zone increased during the 1st month after ablation (P < .001), whereas there was no difference by the 3rd month; subsequently, the tumors showed reduction in size at 6, 9, and 12 months (all P < .001). Complete disappearance of tumors occurred in 68% of patients (577 of 847; 69% [466 of 673] in the T1a group vs 64% [111 of 174] in the T1b group; P < .001). The postablation disease progression rate was 1.1% (nine of 847 patients; 0.9% [six of 673 patients] in the T1a group vs 1.7% [three of 174 patients] in the T1b group; P = .54). The overall complication rate was 3.4% (29 of 847 patients; 2.7% [18 of 673 patients] in the T1a group vs 6.3% [11 of 174 patients] in the T1b group; P = .02). Conclusion This multicenter study provided evidence that thermal ablation is an effective and safe treatment option in selected -patients with solitary T1N0M0 papillary thyroid carcinoma. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Baek and Cho in this issue.

Microwave ablation for papillary thyroid cancer located in the thyroid isthmus: a preliminary study

PURPOSE

To assess the feasibility, efficacy, and safety of ultrasound (US)-guided microwave ablation (MWA) for the treatment of papillary thyroid cancer (PTC) located in the thyroid isthmus.

MATERIALS AND METHODS

Thirty-four patients (mean age, 43 ± 11 years; 26 women) with isthmic PTC treated with MWA between June 2014 and September 2020 were included in this retrospective study. The follow-up time after MWA was 17 ± 9 months (range, 8-50 months). Changes in thyroid function, parathyroid function, and tumor size were evaluated, along with the rates of tumor disappearance and complications.

RESULTS

The treatment was technically feasible and successfully completed in all 34 patients (100%). Measures of thyroid function (i.e. serum triiodothyronine, free thyroxine, and thyrotropin) and parathyroid function (i.e. serum calcium and intact parathyroid hormone) showed no changes from pretreatment levels at 1, 3, and 6 months after MWA (p > 0.05 for all). Tumor size was found to be increased at 1 and 3 months after MWA compared with before MWA (p < 0.05). However, the tumor sizes measured at 6, 9, 12, and 18 months after MWA were smaller than the pretreatment sizes (p < 0.05 for all). In 24 cases (70.6%), the tumors completely disappeared on US examination. Five cases (2.9%) experienced side effects from MWA treatment, but no major or minor complications were recorded.

CONCLUSION

The results of this study demonstrate that US-guided MWA is a feasible, effective, and safe treatment option for selected patients with PTC located in the thyroid isthmus.

Efficacy and safety of microwave ablation for cervical metastatic lymph nodes arising post resection of papillary thyroid carcinoma: a retrospective study

Purpose: To evaluate the efficacy and safety of microwave ablation (MWA) for cervical metastatic lymph nodes (LNs) post resection of papillary thyroid cancer (PTC).Materials and methods: From November 2015 to November 2018, 14 patients with 38 cervical metastatic LNs treated by MWA were included in this retrospective study. Wilcoxon signed rank test was used to compare the changes of LN and serum thyroglobulin levels pre- and post-ablation.Results: The technical success rate in this study was 100% (38/38). The mean follow-up time was 23.6 ± 9.3 months. On pre-ablation contrast-enhanced ultrasound, 25 LNs showed high-enhancement, 8 LNs showed iso-enhancement, and 5 LNs showed low-enhancement. The median largest diameter of LNs at pre-ablation and 3, 6, 9, 12, 18, 24, and 36 months post-ablation was 11.5 mm and 9.5, 9.0, 8.0, 8.0, 8.0, 7.0, and 6.0 mm, respectively. The median volume of LNs at pre-ablation and 3, 6, 9, 12, 18, 24, and 36 months post-ablation were 251.2 mm³ and 206.7, 167.2, 166.2, 155.7, 153.9, 153.9, and 113.1 mm³, respectively. The largest diameter and the volume of the cervical metastatic LNs at the last post-ablation was significantly smaller than the pre-ablation level (p = .0016; p = .0018). Serum Tg level at the last post-ablation (median 1.25 ng/mL) was significantly lower than the pre-ablation level (median 8.35 ng/mL) (p = .001). There were no complications.Conclusion: MWA is a safe and effective novel treatment option for cervical metastatic LN that emerge post resection of PTC.

A Retrospective Study of Lymph Node Yield in Lateral Neck Dissection for Papillary Thyroid Carcinoma

OBJECTIVE

Lateral neck dissection (LND) is important in managing papillary thyroid carcinomas (PTCs). This study aimed to evaluate the relationship between lymph node yield (LNY) for LND and patient outcomes, specifically postoperative serum thyroglobulin levels (sTG) and radioiodine uptake on thyroid scan, and to estimate a threshold LNY to signify adequate LND.

METHODS

Patients diagnosed with PTC who underwent LND from 2006 to 2015 at a single institution were included. Linear regression with restricted cubic splines was used to characterize the association of LNY with outcomes. Outcomes were log-transformed to achieve a more symmetric distribution prior to regression. For nonlinear associations, a Monte Carlo Markov Chain procedure was used to estimate a threshold LNY associated with postoperative outcome. This threshold was then used to define high LNY versus low LNY in the subsequent analyses.

RESULTS

In total, 107 adult patients were included. There was a significant relationship between LNY and postoperative sTG level (P = .004), but not radioiodine uptake (P = .64). An LNY of 42.96 was identified, which was associated with the maximum change in sTG level. No association was found between LNY groups (LNY ≥ 43 vs < 43) and radioiodine uptake, risk of complication, or longer operative times (all P > .05). High LNY was associated with a decrease in log(sTG) (estimate = -1.855, P = .03), indicating that adequacy of LND is associated with an 84.4% decrease in sTG.

CONCLUSION

These results suggest an association between LNY and postoperative sTG level, with an estimated threshold of 43 nodes. This has implications for adequate therapeutic LND; additional work is needed to validate thresholds for clinical practice.