Preservation of recurrent laryngeal nerve invaded by differentiated thyroid cancer

Recovery of Recurrent Laryngeal Nerve Function With Neoadjuvant Treatment: Neural Characterization

OBJECTIVES

Neoadjuvant targeted therapy has emerged as a promising treatment strategy for locally aggressive thyroid cancer. Its impact on tumor and adjacent tissues remains a nascent area of study. Here we report on a series of six subjects with locally advanced thyroid cancer and recurrent laryngeal nerve (RLN) paralysis who experienced recovery of RLN function with neoadjuvant treatment and describe the morphologic and electrophysiologic characteristics of these recovered nerves.

METHODS

This is a multicenter retrospective review. Descriptive analysis was conducted to examine the following parameters for recovered nerves: (1) nerve morphology, characterized as Type A (involving epineurium only) versus Type B (extending beyond epineurium); (2) proximal stimulability (normal vs. abnormal vs. absent); and (3) surgical management (resection vs. preservation).

RESULTS

Six subjects with unilateral VFP were identified. Median time to return of VF mobility was 3 months (range 2-13.5). All nerves (100%) were noted to have Type A morphology at surgery. Proximal stimulability was normal in four subjects (66.7%), abnormal in one (16.7%), and absent in one (16.7%). Nerves that had improvement of function through neoadjuvant therapy were able to be surgically preserved in five subjects (83.3%).

CONCLUSIONS

This represents the first characterization of RLNs that have recovered function with neoadjuvant treatment of locally advanced thyroid cancer. Although much remains unknown, our findings indicate carcinomatous neural invasion is a reversible process and recovered nerves may demonstrate normal morphology and electrophysiologic activity.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3415-3419, 2024.

The Effect of Hemithyroidectomy in Papillary Thyroid Carcinoma with an Exclusive Involvement of the Recurrent Laryngeal Nerve: A Retrospective Study with a Propensity Score-Matched Analysis

BACKGROUND

Involvement of the recurrent laryngeal nerve (RLN) in papillary thyroid carcinoma (PTC) is an important prognostic factor and is associated with a higher risk of recurrence. This study aimed to retrospectively analyze the outcomes of patients treated with hemithyroidectomy (HT) in PTC patients with an exclusive RLN invasion who could not tolerate staged surgery, did not wish to undergo another operation, or had other reasons.

METHODS

A retrospective review was conducted on 163 patients with PTC and exclusive RLN involvement at our institution between 2013 and 2019. Patients were divided into a total thyroidectomy (TT) group and HT group. The clinicopathologic factors and prognostic outcomes were compared between the two groups. A propensity score-matched analysis was carried out to reduce selection bias, with the following covariates: gender, age, tumor size, multifocality, central lymph node metastasis (CLNM), and RLN resection. The Kaplan-Meier method was used for a comparison of recurrence outcomes.

RESULTS

In the baseline data of the 163 PTC patients, tumor size (p < 0.001), multifocality (p = 0.011), CLNM (p < 0.001), and RLN resection (p < 0.008) in the TT and HT groups differed significantly, whereas age and gender did not differ between the two groups. The TT group reported significantly higher temporary and permanent hypoparathyroidism than the HT group (p < 0.001 and p = 0.042, respectively). With 72-month median follow-up, 11 (6.7%) patients developed recurrence. After propensity score matching, 24 patients with HT and 43 patients with TT were included. Recurrence-free survival (RFS) in the matched samples showed no difference between the TT and HT groups (p = 0.092).

CONCLUSION

Our results indicate that HT may be a feasible treatment for PTC patients with exclusive RLN involvement in specific circumstances without significantly increasing the risk of recurrence. Performing a thorough preoperative examination is crucial to exclude multifocal tumors and lymph node metastasis before undergoing HT.

Impact of thyroid carcinoma invasion of recurrent laryngeal nerve on cervical lymph node metastasis

PURPOSE

Papillary thyroid carcinoma (PTC) has a favorable prognosis. However, involvement of the recurrent laryngeal nerve (RLN) significantly increases the risk of recurrence. RLN invasion was an important factor in determining the extent of thyroid surgery. The purpose of this study was to compare clinicopathologic features and characterize risk factors of central and lateral lymph node metastasis (LLNM) of RLN invasion in patients with PTC.

METHODS

A retrospective review was conducted of 130 patients with PTCs who had exclusive tumor involvement of the RLN at our institution between January 2014 and February 2019. All patients underwent total thyroidectomy and high-dose radioactive iodine (RAI) therapy. The clinicopathologic factors and prognostic outcomes of the patients with solitary and multiple RLN involvements were compared. Kaplan-Meier method was performed to compare the outcomes of tumor recurrence. Univariate and multivariate logistic regression analyses were used to identify risk factors associated with LLNM.

RESULTS

The invasion of the RLN was similar on both sides, with 58.5% on the right, 40.0% on the left, and 1.5% on both sides. Significant differences were observed in tumor size (p < 0.001), lymph node metastasis classification (p = 0.002), RLN resection (p < 0.001), and thyroglobulin (p = 0.010) in the solitary and multiple groups. During the median follow-up of 67 months, 9 (6.9%) patients developed recurrence. There were no statistical differences in recurrence for age, tumor size, gender, multifocality, lymph node metastasis (LNM), and RLN resection. According to receiver operating characteristic (ROC) curve analyses, a cut-off of tumor size > 1.7 cm was identified as the most sensitive and specific predictor of RLN with multiple involvements or LNM invasion. Univariate and multivariate analyses revealed that central lymph node metastasis (CLNM) and RLN invasion by LNM can serve as independent risk factors for LLNM (p = 0.006 and p < 0.001, respectively).

CONCLUSION

Our results indicate that recurrence was comparable in patients with solitary and multiple RLN involvements. Multiple RLN involvement was associated with pathological features such as larger tumors, RLN resection, and LLNM. The presence of LNM invading RLN and multiple nerve involvement increases the risk of intraoperative RLN resection. A higher risk of multiple invasion or LNM invasion should be considered when tumor size > 1.7 cm. The presence of CLNM and RLN invaded by LNM were independent predictors for LLNM, which could aid surgeons in deciding on lateral lymph node dissection.

Shaving Papillary Thyroid Carcinoma Involving Functioning Recurrent Laryngeal Nerve: Safety of Incomplete Tumor Resection and Nerve Sparing

BACKGROUND

Whether to sacrifice or spare the recurrent laryngeal nerve (RLN) when papillary thyroid carcinoma (PTC) involves a functioning RLN remains controversial. Oncological outcomes after shaving PTC with gross remnant on the RLN have been rarely reported. The objective of this study was to evaluate the oncological outcomes of patients who underwent shaving of a PTC from the RLN, leaving a gross residual tumor with the intent of vocal function preservation.

METHODS

A retrospective, cohort study was conducted in 47 patients who were determined to have PTC invasion of the RLN via intraoperative inspection and underwent tumor shaving with macroscopic remnant (R2 resection) less than 1 cm in length and 4 mm in thickness. Median follow-up period was 93 (range, 60-215) months. The primary endpoint was the recurrence-free survival and the progression-free survival. Secondary endpoints were biochemical outcomes (serum thyroglobulin) and vocal cord function.

RESULTS

Of the 47 patients, five (10.6%) patients showed recurrence (central neck, 3; lateral neck, 2) without death or distant metastasis. The RLN was resected along with the tumor in one (2.1%) patient who presented with progression of the residual tumor. Postoperative temporary vocal cord paralysis occurred in six (12.8%) patients without permanent cases. The final nonstimulated serum thyroglobulin was 0.7 ± 1.8 ng/ml.

CONCLUSIONS

Shaving a tumor from a RLN with gross residual disease may be considered an alternative strategy to preserve vocal function when complete tumor resection with nerve preservation is impossible in patients with PTC invading a functioning RLN.

Cervical exenteration and its variants for locally advanced thyroid cancer: when, why, and how?

PURPOSE OF REVIEW

To describe the modern surgical approach for management of advanced thyroid cancers infiltrating the cervicovisceral axis with special attention to well differentiated tumors not amenable to organ-sparing techniques. In particular, cervical exenteration, herein defined as the sum of total thyroidectomy, central compartment and lateral neck dissections, variously associated with total laryngectomy and possible partial or total pharyngoesophagectomy, represents an extreme surgical procedure that, in properly selected cases, allows for reasonable palliation of central compartment life-threatening signs/symptoms if not cure for an advanced oncologic condition.

RECENT FINDINGS

Cervical exenteration is not contraindicated by the presence of limited distant metastases at presentation. Even though it requires that the patient is in general good health as it can be associated with a number of complications and long in-hospital stay, when appropriately planned and performed according to the most recent reconstructive nuances, it allows good oncologic outcomes that are not inferior to those described for similarly advanced primaries of the upper aerodigestive tract. In addition, quality of life and functional results are not significantly different from those described after total laryngectomy for primary laryngeal squamous cell carcinomas.

SUMMARY

Cervical exenteration requires a tertiary, expert, multidisciplinary effort in terms of diagnosis, surgical performance, and postoperative care. A patient-centered decision process is strongly warranted taking into consideration alternative therapeutic and symptom-based palliative strategies.

Surgical strategy of locally advanced differentiated thyroid cancer

Approximately 20% of patients with differentiated thyroid cancer (DTC) have direct tumor extension with invasion of the surrounding tissues such as the larynx, trachea, esophagus, or recurrent laryngeal nerve. Recent progress of molecular-targeted therapy, such as the use of tyrosine kinase inhibitors, improves survival outcome in patients with advanced DTC. However, induction of tyrosine kinase inhibitors for locally-advanced DTC has presented novel fatal adverse events including fistula in patients with infiltration toward to the trachea, pharynx and esophagus, and fatal bleeding in patients with great vessel invasion. Surgery therefore still has an important role in DTC management, particularly in local control. The surgical strategy for laryngeal/tracheal invasion, which commonly occurs by DTC, is decided according to the extension (depths and area) of the tumor. The "shave procedure" is performed when the tumor has superficially invaded the larynx/trachea. However, intra-luminal extension requires resection and reconstruction of the larynx/trachea wall. Large veins, such as the internal jugular vein and the subclavian vein, are also frequently directly invaded by DTC. Three types of jugular vein reconstruction have been advocated to avoid fatal complications according to bilateral jugular vein ligation. The majority of carotid artery invasion by DTC can be managed with tumor resection of the sub-adventitial layer without reconstruction surgery using an artificial vessel. In this review article, we examine surgery for advanced DTC, showing the surgical strategy toward DTC that has invaded the laryngotracheal, recurrent laryngeal nerve, esophagus/hypopharynx, or great vessels.

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.

A large-scale study of patients with preoperative vocal cord paralysis associated with thyroid disease and related clinicopathological features

BACKGROUND

The performance of thyroidectomies has been increasing over the last decade due to the growing prevalence of thyroid diseases. The purpose of this study was to investigate the clinical significance of preoperative vocal cord paralysis (VCP) associated with thyroid disease and other incidences of malignant or benign lesions, as well as different thyroid pathological features. Additionally, the epidemiological changes of thyroid diseases with preoperative VCP were investigated.

METHODS

Ninety-nine out of 12,530 patients with preoperative VCP who had undergone thyroid surgery for various diseases in the Zhejiang Cancer Hospital from January 2007 to December 2015 were identified. Their clinicopathological data was recorded and case distributions from different years and intraoperative recurrent laryngeal nerve statuses were retrospectively analyzed.

RESULTS

The incidence of preoperative VCP in 2007 was reported to be 1.53% (9/590) and had decreased to 0.53% (12/2,247) by 2015 (P < 0.05). Among the 99 patients with preoperative VCP, 81 had malignancies (81.82%), while 18 (18.18%) had benign thyroid diseases. The incidences of preoperative VCP in malignant and benign diseases were 1.13% (81/7,159) and 0.35% (18/5,371), respectively (P < 0.05). There were only 5 (0.04%, 5/12,530) cases of papillary thyroid microcarcinoma with preoperative VCP. There was no statistical difference between the incidence of preoperative hoarseness in malignant 69.14% (56/81) and benign diseases 61.11% (11/18) with preoperative VCP.

CONCLUSIONS

The preoperative VCP incidence rate had gradually decreased with an increased proportion of papillary thyroid cancer. Preoperative voice symptoms do not necessarily suggest a malignancy. Selective rather than routine preoperative laryngoscopic examinations should be performed on papillary thyroid microcarcinomas. The probability of preoperative VCP in malignancy was significantly higher than in benign lesions.

Advanced Differentiated Thyroid Cancer: A Complex Condition Needing a Tailored Approach

Differentiated thyroid cancers (DTCs) are slow-growing malignant tumours, including papillary and follicular carcinomas. Overall, prognosis is good, although it tends to worsen when local invasion occurs with bulky cervical nodes, or in the case of distant metastases. Surgery represents the main treatment for DTCs. However, radical excision is challenging and significant morbidity and functional loss can follow the treatment of the more advanced forms. Literature on advanced thyroid tumours, both differentiated and undifferentiated, does not provide clear and specific guidelines. This emerges the need for a tailored and multidisciplinary approach. In the present study, we report our single-centre experience of 111 advanced (local, regional, and distant) DTCs, investigating the rate of radical excision, peri-procedural and post-procedural complications, quality of life, persistence, recurrence rates, and survival rates. Results are critically appraised and compared to the existing published evidence review.

Pathological Analysis of Encased Resected Recurrent Nerves in Locally Invasive Thyroid Cancer

Simple Summary

Thyroid cancer encasing the recurrent nerve is rare, and the decision to resect or preserve the nerve is multifactorial. The aim of this retrospective study was to evaluate the rate of actual invasion of the nerve beyond the nerve sheath in cancers encasing the nerve. Fifty-two patients were included: 7 cases of medullary thyroid carcinoma, 8 papillary thyroid carcinomas in children and 37 follicular derived cancers in adults. Tumor-related vocal fold paralysis was present in 30% of cases. The nerve was invaded in 82% of follicular cell-derived tumors, 88% of pediatric cases, and 100% of medullary carcinomas. Only agressive histology was a risk factor for nerve invasion. Vocal fold paralysis was not predictive. To our knowledge, this is one of the largest series with pathologic analysis of resected recurrent nerves, showing a high rate of nerve invasion in these rare cases of cancer encasing the reucrrent nerve.

Abstract

Objective: Thyroid cancer encasing the recurrent nerve is rare, and the decision to resect or preserve the nerve is multifactorial. The objective of this study was to histopathologically analyze resected encased nerves to assess the rate of nerve invasion and risk factors. Materials and Methods: A retrospective study was carried out on consecutive patients with resection of the recurrent nerve for primary or recurrent follicular cell-derived or medullary thyroid carcinoma from 2005 to 2020. Demographics, pathology, locoregional invasion, metastases, recurrences and survival were analyzed. Slides were reviewed blindly by two specialized pathologists (AAG, RC) for diagnosis of invasion deep to the epineurium. Results: Fifty-two patients were included: 25 females; average age, 55 (range 8–87). In total, 87% percent (45/52) were follicular cell-derived with 17/45 (37.8%) aggressive variants; 13% (7/52) were medullary carcinoma. Preoperative vocal fold (VF) paralysis was present in 16/52 (30.7%). Pathologically, the nerve was invaded in 44/52 cases (85%): 82% of follicular cell-derived tumors (37/45), 88% of pediatric cases, and 100% of medullary carcinomas (7/7). Nerve invasion was observed in 11/16 (69%) with preoperative VF paralysis and 33/36 (92%) with normal VF function. Only aggressive histology was correlated with nerve invasion in follicular cell-derived tumors (p = 0.019). Conclusions: The encased nerves were pathologically invaded in 82% of follicular cell-derived tumors and in 100% of medullary carcinomas. Nerve invasion was statistically correlated with aggressive histopathological subtypes and was observed in the absence of VF paralysis in 92% of cases.

Recurrent Laryngeal Nerve Invasion by Thyroid Cancer: Laryngeal Function and Survival Outcomes

BACKGROUND

Recurrent laryngeal nerve (RLN) invasion by thyroid carcinoma represents an advanced disease status with potentially significant co-morbidity.

METHODS

In a retrospective single-center study, we included patients with invaded RLNs operated on while using nerve monitoring techniques. We studied pre-, intra-, and postoperative parameters associated with postoperative vocal cord paralysis (VCP); 5-year recurrence-free survival (RFS); and 5-year overall survival (OS) in addition to two subgroup analyses of postoperative VCP in patients without preoperative VCP and based on source of RLN invasion.

RESULTS

Of 65 patients with 66 nerves-at-risk, 39.3% reported preoperative voice complaints. Preoperative VCP was documented in 43.5%. The RLN was invaded by primary tumor in 59.3% and nodal metastasis in 30.5%. Papillary thyroid carcinoma was the most common pathologic subtype (80%). After 6 months, 81.8% had VCP. Complete tumor resection of the RLN was not associated with 5-year RFS (p = 0.24) or 5-year OS (p = 0.9). Resecting the RLN did not offer statistically significant benefit on 5-year RFS (p = 0.5) or 5-year OS (p = 0.38). Radioactive Iodine (RAI) administration was associated with improvement in 5-year RFS (p = 0.006) and 5-year OS (p = 0.004). Patients without preoperative VCP had higher IONM amplitude compared with patients with VCP. After a mean follow-up of 65.8 months, 35.9% of patients had distant metastases, whereas 36.4% had recurrence.

CONCLUSION

Preoperative VCP accompanies less than half of patients with RLN invasion. Invaded RLNs may have existent electrophysiologic stimulability. Complete tumor resection and RLN resection were not associated with better 5-year RFS or OS, but postoperative RAI was.

LEVEL OF EVIDENCE

4 Laryngoscope, 2022.

Revision Thyroid Surgery

The incidence of recurrence in well-differentiated thyroid malignancies range from 10 to 30%. It is estimated that about 31-46% of patients with differentiated thyroid cancer will have the persistent disease and 1.2-6.8% will have structural recurrences during post-operative monitoring, depending on the initial therapy and prognostic variables. It is challenging to decide on treatment versus active monitoring following repeated or persistent tumour detection. The biological factors of the tumour and the patient guide us in the overall decision-making. Revision thyroid surgery is technically challenging. The morbidity encountered during the revision surgery is related to the anatomy of the region undergoing dissection, the degree of fibrosis and scarring from prior surgery and the operating surgeon's experience. Successful comprehensive management of revision thyroid surgery needs a multi-disciplinary approach. This review article highlights the definition, indications for revision surgery, identification of recurrent disease, management of parathyroid and recurrent laryngeal nerves with neuromonitoring.

Intraoperative Management of the Recurrent Laryngeal Nerve Transected or Invaded by Thyroid Cancer

Thyroid cancer often invades the recurrent laryngeal nerve (RLN), causing vocal cord paralysis. In such patients, the invaded portion of the RLN usually needs to be resected through curative surgery. We attempt to preserve the nerve by performing sharp dissection in such cases. During nerve dissection, an intraoperative nerve monitoring system helps identify the course of the RLN in the fibrous tissue around the tumor or even within the tumor, and also helps evaluate the nerve integrity. Because of extensive dissection, the preserved RLN may become much thinner than its original thickness. We refer to this procedure as "partial layer resection" of the RLN. In our cases, although the dissected RLNs became thinner, we found that vocal cord function recovered in most patients. If the RLN is fully involved by thyroid cancer or response of the vocal cord against electric stimulation to the RLN is lost, we resect the portion of the RLN together with the tumor and repair it using one of the reconstruction techniques. When a unilateral RLN is resected, the vocal cord on that side is paralyzed. Symptoms include hoarseness, mis-swallowing, and short phonation. RLN reconstruction using one of the reconstruction techniques leads to the recovery of phonatory and swallowing function, although the normal motion of the vocal cord on the side of the anastomosis is not restored. We used direct anastomosis, free nerve grafting, ansa cervicalis-RLN anastomosis, and vagus-RLN anastomosis to reconstruct the RLN. Thyroid cancer often invades the RLN near the Berry's ligament. In such patients, surgeons might assume that reconstruction of the RLN may not be possible because the peripheral stump of the RLN cannot be observed. However, if we divide the inferior pharyngeal constrictor muscles along the lateral edge of the thyroid cartilage, the peripheral RLN can be identified, and nerve reconstruction can be performed. We refer to this procedure as "laryngeal approach".In summary, of the patients with thyroid cancer who required resection of the RLN, RLN reconstruction led to the recovery of phonatory function. We suggest that all thyroid surgeons familiarize themselves with these reconstruction techniques.

Optimal Management of the Unilateral Recurrent Laryngeal Nerve Involvement in Patients with Thyroid Cancer

Simple Summary

Recurrent laryngeal nerve (RLN) is the second most common structure invaded by primary or metastatic thyroid cancer. However, little is known about the optimal procedure for maintaining vocal function in patients with unilateral RLN involvement in thyroid cancer. This study aimed to evaluate various parameters of vocal function to establish the optimal management of thyroid cancer patients with unilateral RLN involvement. Based on our findings, we propose that for optimal management of unilateral RLN involvement in thyroid cancer, first, sharp dissection should be performed, and if this is impossible, a simultaneous RLN reconstruction procedure should be adopted whenever possible. These findings may help improve management of RLN involvement in patients with thyroid cancer and ensure vocal function preservation.

Abstract

We aimed to determine the optimal management of recurrent laryngeal nerve (RLN) involvement in thyroid cancer. We enrolled 80 patients with unilateral RLN involvement in thyroid cancer between 2000 and 2016. Eleven patients with preoperatively functional vocal folds (VFs) underwent sharp tumor resection to preserve the RLN (shaving group). Thirty-three patients underwent RLN reconstruction with RLN resection (reconstruction group). We divided the reconstruction group into two subgroups based on preoperative VF mobility (normal-reconstruction and paralyzed-reconstruction subgroups). In the cases where RLN reconstruction was difficult, phonosurgeries including arytenoid adduction (AA), with or without thyroplasty type I, or nerve muscle pedicle implantation with AA were performed later (phonosurgery group). We evaluated and compared vocal function among the evaluated periods and different groups. Postoperative vocal function in the shaving and normal-reconstruction subgroups was favorable. There were no significant differences between the two groups. In the paralyzed-reconstruction and phonosurgery groups, postoperative vocal function was significantly improved, and vocal function in the paralyzed-reconstruction subgroup was significantly better than that in the phonosurgery group. For optimal management of unilateral RLN involvement in thyroid cancer, first, sharp dissection should be performed, and if this is impossible, a simultaneous RLN reconstruction procedure should be adopted whenever possible.

Clinical outcomes of T4a papillary thyroid cancer with recurrent laryngeal nerve involvement: a retrospective analysis

Preoperative vocal cord palsy (VCP) may indicate locally invasive papillary thyroid cancer (PTC); using this relationship, we evaluated the clinical outcomes and risk factors for recurrence in post-thyroidectomy T4a PTC patients with recurrent laryngeal nerve (RLN) involvement. We retrospectively investigated thyroidectomy patients, recorded their clinical factors, recurrence rate, and pathological findings, and analysed the relationship between recurrence rate and clinical factors. Of 72 patients, 37 (51%) had preoperative VCP and 35 (49%) had normal preoperative vocal cord movement with confirmed intraoperative RLN invasion. Tracheal and esophageal invasion was observed in 13 (18%) and 15 (21%) patients, respectively. Thyroid cancer recurred in 18 (25%) patients over 58 months, resulting in 2 (3%) deaths. Recurrence was not associated with surgical extent, organ invasion, enlarged tumour size, or lymph node infiltration (p > 0.05). The recurrence rate was significantly higher in patients with positive resection margins (p < 0.05). T4a PTC patients with RLN involvement showed a poor prognosis. The recurrence rate was not affected by preoperative VCP, intraoperative detection of RLN invasion, nerve resection, nerve preservation by shaving, lymph node metastasis, or tracheal or esophageal invasion. The most important prognostic factor for recurrence was a positive resection margin.

Novel surgical methods for reconstruction of the recurrent laryngeal nerve: Microscope-guided partial layer resection and intralaryngeal reconstruction of the recurrent laryngeal nerve

BACKGROUND

The optimal strategy for surgical management of papillary thyroid carcinoma invasion of the recurrent laryngeal nerve remains controversial. Our aim was to evaluate the efficacy of 2 surgical methods and provide detailed descriptions of microscope-guided partial layer resection and intralaryngeal reconstruction of the recurrent laryngeal nerve.

METHODS

This retrospective study enrolled 85 patients with papillary thyroid carcinoma who underwent initial surgical excision for invasion of the recurrent laryngeal nerve. Twenty-seven patients (28 recurrent laryngeal nerve sites) underwent partial layer resection, and 11 patients (11 recurrent laryngeal nerve sites) underwent intralaryngeal reconstruction of the recurrent laryngeal nerve. The remaining patients underwent either only resection or resection with immediate reconstruction of the recurrent laryngeal nerve. Pre and postoperative phonetic function and rates of locoregional recurrence were extracted from medical charts for analysis.

RESULTS

Isolated locoregional recurrence specific to the aerodigestive tract was identified in 1 patient (3.7%) in the partial layer resection group and 1 patient (9.1%) in the intralaryngeal reconstruction group. Seventy-five percent of patients in the partial layer resection group recovered or had preserved vocal cord function, and the mean maximum phonation time of the patients with postoperative complete vocal cord palsy was 15.3 seconds. The mean maximum phonation time of the patients, excluding 4 patients with permanent stoma in the intralaryngeal reconstruction group, was 22.3 seconds. The mean maximum phonation time of either group was longer than that of patients with recurrent laryngeal nerve resection only and comparable with that of patients with recurrent laryngeal nerve resection and immediate reconstruction.

CONCLUSION

Patients who underwent either partial layer resection or intralaryngeal reconstruction had low rates of locoregional recurrence specific to the aerodigestive tract and good postoperative functional outcomes.

The revised clinical practice guidelines on the management of thyroid tumors by the Japan Associations of Endocrine Surgeons: Core questions and recommendations for treatments of thyroid cancer

The Japan Associations of Endocrine Surgeons has developed the revised version of the Clinical Practice Guidelines for Thyroid Tumors. This article describes the guidelines translated into English for the 35 clinical questions relevant to the therapeutic management of thyroid cancers. The objective of the guidelines is to improve health-related outcomes in patients with thyroid tumors by enabling users to make their practice evidence-based and by minimizing any variations in clinical practice due to gaps in evidential knowledge among physicians. The guidelines give representative flow-charts on the management of papillary, follicular, medullary, and anaplastic thyroid carcinoma, along with recommendations for clinical questions by presenting evidence on the relevant outcomes including benefits, risks, and health conditions from patients' perspective. Therapeutic actions were recommended or not recommended either strongly (◎◎◎ or XXX) based on good evidence (😊)/good expert consensus (+++), or weakly (◎, ◎◎ or X, XX) based on poor evidence (😣)/poor expert consensus (+ or ++). Only 10 of the 51 recommendations given in the guidelines were supported by good evidence, whereas 35 were supported by good expert consensus. While implementing the current guidelines would be of help to achieve the objective, we need further clinical research to make our shared decision making to be more evidence-based.

Modern surgery for advanced thyroid cancer: a tailored approach

Surgical treatment of advanced thyroid malignancy can be morbid, compromising normal functions of the upper aerodigestive tract. There is a paucity of guidelines dedicated to the management of advanced disease. In fact, there is not even a uniform definition for advanced thyroid cancer currently. The presence of local invasion, bulky cervical nodes, distant metastases or recurrent disease should prompt careful preoperative evaluation and planning. Surgical strategy should evolve from multidisciplinary discussion that integrates individual disease characteristics and patient preference. Intraoperative neuromonitoring has important applications in surgery for advanced disease and should be used to guide surgical strategy and intraoperative decision-making. Recent paradigm shifts, including staged surgery and use of neoadjuvant targeted therapy hold potential for decreasing surgical morbidity and improving clinical outcomes. Modern surgical planning provides optimal treatment for each patient through a tailored approach based on exact extent and type of disease as well as incorporating appreciation of surgical complications, patient preferences and intraoperative findings.

Surgical management of the compromised recurrent laryngeal nerve in thyroid cancer

Surgical management of thyroid cancer requires careful consideration of the recurrent laryngeal nerve and its impact on glottic function. Management of the compromised recurrent laryngeal nerve is a complex task, requiring synthesis of multiple elements. The surgeon must have an appreciation for preoperative recurrent laryngeal nerve function, intraoperative anatomic and electromyographic information, disease characteristics, and relevant patient factors. Preoperative clinical evaluation including preoperative laryngoscopy and assessment of recurrent laryngeal nerve risk is essential to formulating a surgical plan and providing appropriate patient counseling. Intraoperative neuromonitoring information has significant implications for surgical management of the injured or invaded recurrent laryngeal nerve and informs strategy with respect to staging of bilateral surgery. Disease characteristics and patient-related factors, including patient preference, must be considered with intraoperative decision-making. Multidisciplinary discussion and patient communication are essential for effective management and successful surgical outcome.

Immediate Surgery Might Be a Better Option for Subcapsular Thyroid Microcarcinomas

For high-risk papillary thyroid microcarcinomas (PTMCs), immediate surgery is recommended. This study aimed to evaluate the location of PTMCs in the thyroid lobe and determine whether location is associated with an aggressive biology and the necessity of immediate surgery. This retrospective study included 288 patients who underwent initial surgery for PTMC. Clinical data were extracted. Subcapsular thyroid microcarcinomas (STMs) and nonsubcapsular thyroid microcarcinomas (NSTMs), distinguished by ultrasound, were compared in terms of tumour size, extrathyroidal extension, cervical lymph node metastasis, and multifocality. The preoperative ultrasound features predictive of recurrent laryngeal nerve (RLN) involvement were assessed. There were no statistical differences in tumour size (P = 0.985), multifocality (P = 0.866), lymph node metastases to the central compartment (P = 0.154), or lateral lymph node metastases (P = 0.929) between STM and NSTM groups. Macroscopic extrathyroidal extension was exclusively found in the STM group. For assessing RLN involvement, the sensitivity, specificity, and positive predictive value of the presence of an abnormal thyroid capsule margin between the STM and the presumed RLN course, assessed on preoperative ultrasonography images, were 100%, 43.3%, and 43.3%, respectively. Immediate surgery appears to be a better option than conservative treatment for these high-risk STM patients.

International neuromonitoring study group guidelines 2018: Part II: Optimal recurrent laryngeal nerve management for invasive thyroid cancer-incorporation of surgical, laryngeal, and neural electrophysiologic data

The purpose of this publication was to inform surgeons as to the modern state-of-the-art evidence-based guidelines for management of the recurrent laryngeal nerve invaded by malignancy through blending the domains of 1) surgical intraoperative information, 2) preoperative glottic function, and 3) intraoperative real-time electrophysiologic information. These guidelines generated by the International Neural Monitoring Study Group (INMSG) are envisioned to assist the clinical decision-making process involved in recurrent laryngeal nerve management during thyroid surgery by incorporating the important information domains of not only gross surgical findings but also intraoperative recurrent laryngeal nerve functional status and preoperative laryngoscopy findings. These guidelines are presented mainly through algorithmic workflow diagrams for convenience and the ease of application. These guidelines are published in conjunction with the INMSG Guidelines Part I: Staging Bilateral Thyroid Surgery With Monitoring Loss of Signal. Level of Evidence: 5 Laryngoscope, 128:S18-S27, 2018.

Does the recurrent laryngeal nerve recover function after initial dysfunction in patients undergoing thyroidectomy?

Objective

Total thyroidectomy with or without central compartment dissection is the treatment of choice for thyroid carcinoma. Extensive dissection along the recurrent laryngeal nerve (RLN) can lead to vocal cord fixity and hoarseness even without nerve sacrifice. Recovery rates after surgery for thyroid cancers have not been well documented. The aim of the study is to analyze the incidence of vocal cord palsy (VCP) and its recovery rates in patients operated for thyroid cancers. Methodology: We performed a retrospective study on prospectively collected data in 152 thyroidectomy patients with 254 RLNs at risk. All patients underwent a laryngoscopic examination to document vocal cord function in the immediate postoperative period and on subsequent follow-up. Incidence of VCP, recovery rates, univariate and multivariate analysis to identify risk factors for permanent VCP were calculated using binary logistic regression.

Results

In our study, 28% patients underwent redo surgeries and 74% patients had dissection of the central compartment. The immediate postoperative RLN palsy rate was 11.2%, with a palsy rate of 9% and 16.2% in the per primum and redo surgery cohorts. On follow-up, there was complete recovery of VCP in 66.7% of these nerves. The incidence of permanent RLN palsy was 3.9%. The mean time to recovery was 9.6 months.

Conclusion

Vocal cord dysfunction recovered in most patients in this high-risk cohort. There was a significant recovery even in the redo surgery group and a policy of watchful waiting is recommended in the absence of severe symptoms.

Level of Evidence

III.

Surgical Perspectives in Head and Neck Cancer

Head and neck cancer treatment is a complex multidisciplinary undertaking. Cancer cure and survival is a primary goal, yet safe-guarding appearance and function to preserve the quality of life are similarly critical. The head and neck surgeon remains central to multidisciplinary cancer care, with deep knowledge of operative technique and an even deeper understanding of cancer biology. The surgeon models practice based on the highest levels of scientific evidence, but also takes into consideration the approaches that may best suit an individual patient. The surgeon's role moreover spans the life history of a head and neck cancer patient, from diagnosis to surveillance. The intimacy of this role makes the surgeon a trusted and frequent frame of reference for the patient. In this chapter, we provide an overview of the surgeon's role in head and neck cancer management. We discuss surgical perspectives within the multidisciplinary care team and selectively highlight some of the more provocative clinical scenarios in the field.

Predictive factors and prognosis for recurrent laryngeal nerve invasion in papillary thyroid carcinoma

Background

Recurrent laryngeal nerve (RLN) invasion in papillary thyroid carcinoma (PTC) is one of the main predictors of poor prognosis. The present study investigated the risk factors for RLN invasion in PTC patients.

Methods

A total of 3,236 patients who received thyroidectomy due to PTC in Thyroid and Parathyroid Surgery Center of West China Hospital of Sichuan University were reviewed. Demographics and clinical factors, imaging examination (ultrasonography) characteristics, surgical details, postoperative pathological details, recurrence, and postoperative complications were recorded. Univariate and multivariate analyses were used to study the risk factors of RLN invasion, Kaplan–Meier method was performed to compare the outcomes of tumor recurrence.

Results

Patients with RLN invasion had a higher recurrence rate than those in the control group (p<0.001). Multivariate analyses showed that age greater than 45 years (p<0.001), a largest tumor size bigger than 10 mm (p<0.001), clinical lymph node metastasis (cN1) (p<0.001), posterior focus (p<0.001), extrathyroidal extension (p<0.001), esophageal extension (p<0.001), tracheal extension (p<0.001), and preoperative vocal cord paralysis (p<0.001) were independent predictors for RLN invasion.

Conclusion

PTC patients with RLN invasion have a negative prognosis and a higher recurrence rate. Meticulous operation and careful follow-up of patients with the above factors is recommended.

Management of Invasive Differentiated Thyroid Cancer

BACKGROUND

Invasive disease is a poor prognostic factor for patients with differentiated thyroid cancer (DTC). Uncontrolled central neck disease is a common cause of distressing death for patients presenting in this manner. Advances in assessment and management of such cases have led to significant improvements in outcome for this patient group. This article reviews the patterns of invasion and a contemporary approach to investigation and treatment of patients with invasive DTC.

SUMMARY

Aerodigestive tract invasion is reported in around 10% of case series of DTC. Assessment should include not only clinical history and physical examination with endoscopy as indicated, but ultrasound and contrast-enhanced cross-sectional imaging. Further studies including positron emission tomography should be considered, particularly in recurrent cases that are radioactive iodine (RAI) resistant. Both the patient and the extent of disease should be carefully assessed prior to embarking on surgery. The aim of surgery is to resect all gross disease. When minimal visceral invasion is encountered early, "shave" procedures are recommended. In the setting of transmural invasion of the airway or esophagus, however, full thickness excision is required. For intermediate cases in which invasion of the viscera has penetrated the superficial layers but is not evident in the submucosa, opinion is divided. Early reports recommended an aggressive approach. More recently authors have tended to recommend less aggressive resections with postoperative adjuvant therapies. The role of external beam radiotherapy continues to evolve in DTC with support for its use in patients considered to have RAI-resistant tumors.

CONCLUSIONS

Patients with invasive DTC require a multidisciplinary approach to investigation and treatment. With detailed assessment, appropriate surgery, and adjuvant therapy when indicated, this patient group can expect durable control of central neck disease, despite the aggressive nature of their primary tumors.

True Vocal Fold Immobility in the Setting of Well-Differentiated Thyroid Carcinoma: Unusual Illustrative Cases and Recommendations for Operative Strategy

Objectives:

We present cases of transient true vocal fold (TVF) immobility caused by well-differentiated thyroid carcinoma (WDTC), and review the literature concerning management of WDTC invading the recurrent laryngeal nerve (RLN).

Methods:

A description of the clinical course of 2 patients with WDTC and transient TVF immobility is presented in the context of a review of the literature concerning locally advanced WDTC with extrathyroidal extension and RLN involvement.

Results:

Both patients had papillary thyroid carcinoma with ipsilateral TVF paralysis that resolved completely before operation. During the operation, the RLN was found to be grossly involved with disease and inseparable from the tumor, necessitating resection. Review of the literature revealed the following points that should be considered when confronting an RLN invaded by WDTC. 1) Benign disease can mimic invasive WDTC and must be ruled out. 2) RLN invasion does not carry the same prognostic implications as other categories of extrathyroidal extension of WDTC. 3) RLN sacrifice does not increase the overall survival rate. 4) There is no evidence that a paralyzed RLN will regain function when preserved. 5) The majority of RLNs that function before operation can be expected to function after the operation if preserved.

Conclusions:

Resolution of TVF paralysis should not reduce suspicion of RLN involvement by WDTC. When RLN involvement is discovered during operation, every attempt should be made to preserve a functioning RLN.

Operative management of locally advanced, differentiated thyroid cancer

BACKGROUND

The majority of differentiated thyroid cancer tends to present with limited locoregional disease, leading to excellent long-term survival after operative treatment. Even patients with advanced local disease may survive for long periods with appropriate treatment. The aim of this study is to present our institutional experience of the management of locally advanced differentiated thyroid cancer and to analyze factors predictive of outcome.

METHODS

We reviewed our institutional database of 3,664 previously untreated patients with differentiated thyroid cancer operated between 1986 and 2010. A total of 153 patients had tumor extension beyond the thyroid capsule that invaded the subcutaneous soft tissues, recurrent laryngeal nerve, larynx, trachea, or esophagus. Details on extent of operation and adjuvant therapy were recorded. Disease-specific survival and locoregional recurrence-free probability were determined by the Kaplan-Meier method. Factors predictive of outcome were determined by multivariate analysis.

RESULTS

The median age of the 153 patients with tumor extension beyond the thyroid capsule was 55 years (range 11-91 years). Eighty-nine patients (58.2%) were female. Twenty-three patients (15.0%) were staged as M1 at presentation, and 122 (79.7%) had pathologically involved lymph nodes. The most common site of extrathyroidal extension was the recurrent laryngeal nerve (51.0%) followed by the trachea (46.4%) and esophagus (39.2%). Sixty-three patients (41%) required resection of the recurrent laryngeal nerve due to tumor involvement. After surgery, 20 patients (13.0%) had gross residual disease (R2), 63 (41.2%) had a positive margin of resection (R1), and 70 (45.8%) had complete resection with negative margins (R0). With a median follow-up of 63.9 months, 5-year, disease-specific survival, when stratified by R0/R1/R2 resection, was 94.4%, 87.6%, and 67.9%, respectively (P = .030). The data do not demonstrate a statistical difference in survival between R0 versus R1 (P = .222). The 5-year distant recurrence-free probability for M0 patients was 90.8%, 90.3%, and 70.7% (P = .410). The locoregional recurrence-free probability was 85.8% for R0 patients and 85.5% for R1 patients (P = .593).

CONCLUSION

With an appropriate operative strategy, patients with locally advanced thyroid cancer with an R0 or R1 resection have excellent survival outcome.

Laryngeal examination in thyroid and parathyroid surgery: An American Head and Neck Society consensus statement: AHNS Consensus Statement

This American Head and Neck Society (AHNS) consensus statement discusses the techniques of laryngeal examination for patients undergoing thyroidectomy and parathyroidectomy. It is intended to help guide all clinicians who diagnose or manage adult patients with thyroid disease for whom surgery is indicated, contemplated, or has been performed. This consensus statement concludes that flexible transnasal laryngoscopy is the optimal laryngeal examination technique, with other techniques including laryngeal ultrasound and stroboscopy being useful in selected scenarios. © 2016 Wiley Periodicals, Inc. Head Neck 38: 811-819, 2016.

Treatment Outcomes and Risk Factors for Recurrence After Definitive Surgery of Locally Invasive Well-Differentiated Papillary Thyroid Carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is generally an indolent tumor that has a favorable prognosis. However, locally invasive PTC can recur after treatment, and its optimal treatment is still controversial. This study aimed to evaluate treatment outcomes and identify risk factors for recurrence and survival in patients with locally invasive PTC.

MATERIALS AND METHODS

All consecutive patients who underwent definitive surgery and radioactive iodine therapy for non-distant metastatic invasive PTC were included. Clinical factors, operative and pathological findings, surgical morbidity, and recurrences were recorded. Univariate and multivariate Cox proportional hazard models served to identify factors associated with recurrence-free survival (RFS) and overall survival.

RESULTS

Of the 96 patients, 74 (77%), 52 (55%), 4 (4%), and 14 (15%) had invasion to the recurrent laryngeal nerve (RLN), trachea, larynx, and esophagus, respectively; 39 (41%) had preoperative vocal cord paresis or paralysis; and 24 (25%) developed recurrence during follow-up (median 77 months). The patients with single and multiple organ invasion did not differ significantly in terms of recurrence-free or overall survival (p > 0.05). The patients with and without recurrences did not differ in terms of surgical extent and involving nerve preservation. Multivariate analysis showed that high (≥1 ng/mL) post-ablation stimulated serum thyroglobulin concentration was an independent predictor of poor RFS (p = 0.013).

CONCLUSION

Disease extent, surgical extent, and involving nerve preservation did not associate with recurrence or overall survival outcomes. The post-ablation stimulated thyroglobulin level may be an independent predictor for recurrence. Careful follow-up of patients with this risk factor is recommended.

External-beam radiotherapy for differentiated thyroid cancer locoregional control: A statement of the American Head and Neck Society

The use of external-beam radiotherapy (EBRT) in differentiated thyroid cancer (DTC) is debated because of a lack of prospective clinical data, but recent retrospective studies have reported benefits in selected patients. The Endocrine Surgery Committee of the American Head and Neck Society provides 4 recommendations regarding EBRT for locoregional control in DTC, based on review of literature and expert opinion of the authors. (1) EBRT is recommended for patients with gross residual or unresectable locoregional disease, except for patients <45 years old with limited gross disease that is radioactive iodine (RAI)-avid. (2) EBRT should not be routinely used as adjuvant therapy after complete resection of gross disease. (3) After complete resection, EBRT may be considered in select patients >45 years old with high likelihood of microscopic residual disease and low likelihood of responding to RAI. (4) Cervical lymph node involvement alone should not be an indication for adjuvant EBRT.

Papillary thyroid carcinoma with exclusive involvement of a functioning recurrent laryngeal nerve may be treated with shaving technique

OBJECTIVES

We sought to validate the feasibility of preserving a functioning recurrent laryngeal nerve (RLN) invaded by papillary thyroid carcinoma (PTC) using a shaving technique followed by high-dose radioactive iodine (RAI) therapy.

METHODS

A retrospective review of 34 patients with locally invasive PTC who had exclusive tumor involvement of a functioning RLN was performed. All patients underwent total thyroidectomy and high-dose RAI therapy. A shaving technique was conducted with the goal of leaving the smallest amount of residual tumor as possible while attempting to preserve nerve function. Clinicopathologic factors and oncologic outcomes of the patients with resected RLN (group A, n = 14) and preserved RLN (group B, n = 20) were compared.

RESULTS

The two groups showed no differences in clinicopathologic factors or follow-up period. Mean dose of radioiodine therapy was 245.0 ± 140.3 mCi (range 100-540 mCi). Permanent postoperative vocal cord paralysis after RLN shaving occurred in two patients of group B (10%). Only one patient (5%) in group B had local recurrence at the thyroid bed where the residual tumor was located. The overall recurrence rate was 35.7% (5/14) and 20.0% (4/20) in groups A and B, respectively showing no significant difference (p = 0.525). There were no cases of death due to PTC during the median follow-up of 75 months (range 36-159 months).

CONCLUSIONS

Patients with locally invasive PTC with exclusive involvement of a functioning RLN may be treated by nerve shaving followed by treatment of the macroscopic residual tumor with high-dose RAI therapy.

Management of recurrent/persistent nodal disease in patients with differentiated thyroid cancer: a critical review of the risks and benefits of surgical intervention versus active surveillance

BACKGROUND

The primary goals of this interdisciplinary consensus statement are to define the eligibility criteria for management of recurrent and persistent cervical nodal disease in patients with differentiated thyroid cancer (DTC) and to review the risks and benefits of surgical intervention versus active surveillance.

METHODS

A writing group was convened by the Surgical Affairs Committee of the American Thyroid Association and was tasked with identifying the important clinical elements to consider when managing recurrent/persistent nodal disease in patients with DTC based on the available evidence in the literature and the group's collective experience.

SUMMARY

The decision on how best to manage individual patients with suspected recurrent/persistent nodal disease is challenging and requires the consideration of a significant number of variables outlined by the members of the interdisciplinary team. Here we report on the consensus opinions that were reached by the writing group regarding the technical and clinical issues encountered in this patient population.

CONCLUSIONS

Identification of recurrent/persistent disease requires a team decision-making process that includes the patient and physicians as to what, if any, intervention should be performed to best control the disease while minimizing morbidity. Several management principles and variables involved in the decision making for surgery versus active surveillance were developed that should be taken into account when deciding how best to manage a patient with DTC and suspected recurrent or persistent cervical nodal disease.

Impact of lymph node metastases with recurrent laryngeal nerve invasion on patients with papillary thyroid carcinoma

BACKGROUND

Although rare, invasion by papillary thyroid carcinoma (PTC) of the upper aerodigestive tract significantly affects patients' prognosis and quality of life. Within the central compartment, the recurrent laryngeal nerve (RLN) is most frequently invaded by lymph node metastases (LNM). However, such an invasion has not been described in the literature, although reports on RLN invasion by primary tumors have been published. The present study aimed to characterize LNM with RLN invasion in patients with PTC.

METHODS

The participants of this retrospective investigation were selected from 629 PTC patients who received initial surgical treatment at our institution between January 1981 and December 2012. They included 38 (6%) patients with 40 cases of RLN invasion by LNM (LNM invasion group) and 112 (17.8%) patients with 117 cases of RLN invasion by the primary tumor (primary invasion group).

RESULTS

In the LNM invasion group, 70% of the RLN invasion cases occurred on the right side, whereas those in the primary invasion group were almost equally distributed. RLN invasion caused vocal cord paralysis, affecting 13 nerves (32.5%) in the LNM invasion group and 68 nerves (58%) in the primary invasion group. Significant differences in laterality and preoperative vocal cord paralysis were observed between the two groups. In the LNM invasion group, the longest diameter of metastatic lymph nodes (mean±standard deviation) of patients with RLN paralysis was 21±8 mm, whereas it was significantly different at 14±7 mm in those without RLN paralysis.

CONCLUSIONS

Our results indicate that most patients with RLN invasion by LNM did not experience preoperative vocal cord paralysis. LNM invasion of the RLN (70%) more often occurred on the right side as expected given the complexity and three-dimensional anatomy of the RLN in the right paratracheal region compared to the left. RLN invasion by LNM should be considered if preoperative paratracheal nodal disease, especially when bulky, is noted in the right paratracheal region.

Management of invasive well-differentiated thyroid cancer: an American Head and Neck Society consensus statement. AHNS consensus statement

BACKGROUND

Invasive differentiated thyroid cancer (DTC) is relatively frequent, yet there is a paucity of specific guidelines devoted to its management. The Endocrine Committee of the American Head and Neck Society (AHNS) convened a panel to provide clinical consensus statements based on review of the literature, synthesized with the expert opinion of the group.

METHODS

An expert panel, selected from membership of the AHNS, constructed the manuscript and recommendations for management of DTC with invasion of recurrent laryngeal nerve, trachea, esophagus, larynx, and major vessels based on current best evidence. A Modified Delphi survey was then constructed by another expert panelist utilizing 9 anchor points, 1 = strongly disagree to 9 = strongly agree. Results of the survey were utilized to determine which statements achieved consensus, near-consensus, or non-consensus.

RESULTS

After endorsement by the AHNS Endocrine Committee and Quality of Care Committee, it received final approval from the AHNS Council.

Risk factors for recurrence of papillary thyroid carcinoma with clinically node-positive lateral neck

BACKGROUND

Papillary thyroid carcinoma (PTC) with clinically node-positive lateral neck is more likely to recur after surgery than node-negative PTC. The present study investigated the risk factors for recurrence in PTC patients with clinically node-positive lateral neck.

MATERIALS AND METHODS

This study involved 136 patients with pathologically confirmed PTC and a clinically lymph node (LN)-positive lateral neck but no initial distant metastasis who underwent total thyroidectomy with therapeutic central and lateral neck dissection. Clinicopathologic characteristics, intraoperative findings, postoperative thyroglobulin (Tg) levels, and post-treatment recurrences were examined. Univariate and multivariate analyses were performed to identify factors associated with recurrence-free survival (RFS).

RESULTS

During a median follow-up of 62 months (range 33-90 months), 27 (19.9 %) patients had locoregional or distant recurrences. Univariate analyses showed that primary tumor size (p = 0.049), recurrent laryngeal nerve invasion (p = 0.035), the maximal size of metastatic LN foci (≥1.5 cm; p = 0.012), extranodal extension (p = 0.025), total LN ratio (≥0.26; p = 0.008), American Thyroid Association (ATA) risk categories (p < 0.001), and stimulated serum Tg level (≥4.4; p < 0.001) at the time of radioactive iodine ablation therapy just after thyroidectomy were significant predictors of RFS. Multivariate analyses showed that the maximal size of metastatic foci (p = 0.037), ATA risk categories (p < 0.001), and stimulated Tg level (p < 0.001) were independent predictors of RFS.

CONCLUSIONS

Maximal size of metastatic foci, ATA risk categories, and stimulated serum Tg levels are predictive of recurrence after surgery. Careful follow-up of patients with these risk factors is therefore recommended.

A new strategy for the surgical management of RLN infiltrated by well-differentiated thyroid carcinoma

Well-differentiated thyroid carcinoma (WDTC) represents the most common endocrine malignancy. Despite excellent prognoses exceeding 90% in 10-year follow-up, there are clinically controversial issues. One of these is extrathyroidal tumour extension invading recurrent laryngeal nerve (RLN). The spread outside of the thyroid parenchyma and invasion to the surrounding structures, classified as always T4a, are the most important negative prognostic factor for the WDTC. Conversely, resection of the RLN leads to vocal cord paralysis with hoarseness, possible swallowing problems, and finally decreased quality of life. We propose a new algorithm for intraoperative management based on the MACIS classification, which would allow swift status evaluation pre/intraoperatively and consider a possibility to preserve the infiltrated RLN without compromising an oncological radicality. In the case of a preoperative vocal cord paralysis (VCP) and confirmation of the invasive carcinoma, a resection of the RLN and the nerve graft reconstruction are indicated. Preoperatively, unaffected vocal cord movement and intraoperatively detected RLN infiltration by the invasive WDTC require an individual assessment of the oncological risk by the proposed algorithm. Preservation of the infiltrated RLN is oncologically acceptable only in specific groups of patients of a younger age with a minor size of primary tumour.

Outcome of vocal cord function after partial layer resection of the recurrent laryngeal nerve in patients with invasive papillary thyroid cancer

BACKGROUND

The recurrent laryngeal nerve (RLN) may be involved by thyroid cancer even in patients with functioning vocal cords preoperatively. In such cases, we try to preserve the nerve with sharp dissection. As a result of the dissection, the nerve may become thinner than its original thickness. Here we call this operative procedure "partial layer resection of the RLN," if the thickness of the preserved nerve is less than half of its original size. However, there is no report on postoperative vocal cord function after this procedure.

METHODS

We report on 4,585 patients with papillary thyroid cancer who underwent their initial surgery in Kuma Hospital. Among them, 18 patients underwent "partial layer resection of the RLN." We also performed histologic examinations on the RLNs resected because of cancer invasion in 3 other patients.

RESULTS

Postoperatively, 2 patients had functioning vocal cords, 13 had transient vocal cord paralysis, and the remaining 3 had permanent paralysis. Thus, 83% (15/18) of the present patients who underwent partial layer resection of the RLN had functioning vocal cords 1 year after surgery. In patients with transient paralysis, the phonation efficiency index (PEI) 1 year after operation recovered to normal range from the low PEI immediately after operation. Histologic examinations of resected RLN revealed that 78-82% of the cross-section of the nerve is composed of perineural connective tissue surrounding the nerve fibers.

CONCLUSION

An unexpectedly high proportion (83%) of the patients who underwent partial layer resection of the RLN achieved functioning vocal cords and nearly normal phonation postoperatively.

Vocal fold paralysis in the presence of thyroid disease: management strategies

Background:

The presentation of vocal fold palsy with associated goitre has historically been considered to be due to malignancy with recurrent laryngeal nerve involvement.

Method:

In total, 830 consecutive patients who underwent thyroid surgery were reviewed. Patients with vocal fold paralysis and thyroid disease were examined to determine the aetiology of the paralysis.

Results:

Nine patients were identified with new onset vocal fold paralysis prior to thyroid surgery. Six of the patients with recurrent laryngeal nerve paralysis had benign thyroid disease, and for three of the patients the paralysis was secondary to malignancy.

Conclusion:

Recurrent laryngeal nerve paralysis in the presence of thyroid disease is not pathognomonic for malignancy. The current literature may underestimate the association between vocal fold paralysis and benign thyroid disease. The paper also highlights the importance of recurrent laryngeal nerve preservation in patients who present with palsy and thyroid disease; the relief of benign compression often leads to complete recovery of recurrent laryngeal nerve paralysis.

Thyroid cancer: surgery for the primary tumor

Surgery is the mainstay of therapy for most patients who present with thyroid cancer. The surgeon must select an appropriate procedure based upon pre operative factors such as tumor histology, extent of primary disease, the presence of regional or distant metastases, associated disease in the contralateral thyroid lobe and the potential for post operative adjuvant therapy. Preservation of the vital structures in the central neck, including the recurrent and superior laryngeal nerves and the parathyroid glands is critical as is the maintenance of absolute hemostasis. In this review article we describe the management of Well Differentiated Thyroid Cancer (WDTC) presenting as a solitary nodule, WDTC in a background of multinodular disease and the management of WDTC presenting as advanced local disease. We go onto discuss the impact that regional and distant metastases have on the choice of surgical approach. The focus of this article is WDTC, however the principles of management of the primary in medullary and anaplastic carcinoma are also discussed.

Management of well-differentiated thyroid cancer

This review provides an overview of current guideline recommendations for the clinical evaluation and surgical management of well-differentiated thyroid cancer, and further examines the evidence for controversial topics such as the minimum degree of primary resection, the role of elective central neck dissection, and the extent of lateral neck dissection. Well-differentiated thyroid cancer comprises the majority of thyroid cancers, about 90%, and includes both papillary and follicular carcinomas. Despite convergence of the medical community in establishing treatment guidelines under the American Thyroid Association, there still remain many areas of disagreement.