Cartilage-shaving procedure for the control of tracheal cartilage invasion by thyroid carcinoma

Exceptional Location of a Papillary Carcinoma of the Thyroid

Thyroid cancers are a rare condition; of these, differentiated thyroid carcinomas are the most common and have a good prognosis with timely diagnosis and treatment. In the case of a late diagnosis, these carcinomas can breach the thyroid capsule and invade the laryngo-tracheal axis. The surgical treatment of locally invasive papillary thyroid carcinoma is a complete resection with the preservation of laryngeal functions when it is possible. We report the case of an 80-year-old patient who presented with inspiratory dyspnea and hemoptysis showing endotracheal localization of a papillary carcinoma of the thyroid.

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.

Haemoptysis: An Uncommon Presentation in an Incidental Thyroid Nodule-A Case Report

Thyroid cancers invading the critical structures like trachea, oesophagus, recurrent laryngeal nerve and major vessels are uncommon. Even though uncommon, patients with large thyroid lesion (> 4 cm) or aggressive histology can present with features of invasion. Careful evaluation and appropriate surgical management is needed for optimal outcome. This case is presented to make our otolaryngology-head and neck surgeons aware of such unique situation where an incidental thyroid nodule presenting as haemoptysis due to tracheal invasion.

Analysis of Pattern of Laryngotracheal Invasion by Papillary Thyroid Carcinoma and Their Management: Our Experience

To analyse the pattern of laryngotracheal invasion (LTI) by papillary-thyroid-carcinoma (PTC) and outcomes of their management. We undertook a retrospective chart review to study patterns of LTI by PTC and to evaluate outcomes of surgical modalities used to treat PTC with LTI. Out of 246cases of PTC, 26-cases had LTI (male-12, female-14, mean-age-55.6 years, range 42-73 years). Common clinical presentation were neck swelling, respiratory distress/stridor and vocal cord paralysis in 100%, 8 (30.8%) and 10 (38.5%) cases respectively. PTC was staged according to AJCC-TNM staging system (T4a-24, T4b-02, N1a-12, N1b-14, M0-25, and M1-01). CT-scan showed obvious LTI and tracheal narrowing in 11(42.3%) and 18(69.2%) cases respectively. All cases underwent total thyroidectomy with central-compartment-clearance. Unilateral and bilateral lateral-neck-dissection was performed in 08 and 06cases respectively. Pattern of Intra-operative LTI were as follows: trachea-13cases, trachea and cricoid-05cases, thyroid cartilage-6cases, trachea, cricoid and thyroid cartilage-2 cases and intra-luminal involvement in 4cases. Modified Shin's staging was used to stage LTI. LTI were superficial, deep-extra-luminal and intra-luminal in 13, 09 and 04cases respectively. LTI was managed by shave-excision, window-resection of trachea, sleeve-resection of trachea and anastomosis, partial laryngectomy and total-laryngectomy in 13,02,04,05 and 2 cases respectively. All patients received radio-active-iodine (RAI) and TSH-suppression-therapy post-operatively. Mean follow-up period was two-years (range 18-30 months). One-case had radio-iodine non-avid local recurrence with lung metastases one-year post-operatively. Shave-excision is adequate for tumours not infiltrating into outer perichondrium. Tracheal-resection and total/partial laryngectomy may be required in cases with laryngo-tracheal cartilage or intra-luminal involvement. Adequate surgical excision along with postoperative RAI and TSH-suppression-therapy gives good loco-regional disease control in PTC with LTI.

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.

Laryngotracheal Resection in Thyroid Cancer - Experience from a Single Centre Series of 22 Cases

Involvement of the aerodigestive tract is reported in one-third of patients with locally invasive thyroid cancer. It is associated with significant morbidity and mortality, with airway obstruction being the immediate cause of death in 50% of patients who die of thyroid cancer. Management is challenging and includes the risks of extensive surgery as well as decisions regarding the type of surgery and adjuvant therapy. Retrospective cohort study, reporting institutional experience with patients who underwent laryngotracheal resection for invasive thyroid cancer over the past 10 years. Twenty-two patients were included in the study. All patients had Shin stage 4 disease. The median follow-up was 18 months. Five patients had systemic metastasis at diagnosis. Nineteen patients underwent tracheal resection and end to end anastomosis, and 3 underwent laryngectomy. The mean length of the resected trachea was 2.94 cm. Tracheal releasing manoeuvres were utilized in 11 patients. Three patients required a tracheostomy postoperatively. Other complications included a temporary vocal cord palsy in 5 patients, temporary hypocalcemia in 6 and permanent hypocalcemia in 1 patient. Adjuvant radiotherapy was utilized in 9 patients and I-131 therapy in 13 patients. Three patients died during follow-up. Two patients developed thyroid bed recurrence, two patients developed systemic metastasis on follow-up. Most patients survived for a prolonged period with only biochemical evidence of disease persistence and three with no evidence of disease. Laryngotracheal resection with primary anastomosis is a safe and effective option, providing adequate symptomatic relief as well as prolonged survival in carefully selected patients with invasive Shin stage 4 disease.

Tracheal and Cricotracheal Resection With End-to-End Anastomosis for Locally Advanced Thyroid Cancer: A Systematic Review of the Literature on 656 Patients

Airway involvement by advanced thyroid carcinoma (TC) constitutes a negative prognosticator, besides being a critical clinical issue since it represents one of the most frequent causes of death in locally advanced disease. It is generally agreed that, for appropriate laryngo-tracheal patterns of invasion, (crico-)tracheal resection and primary anastomosis [(C)TRA] is the preferred surgical technique in this clinical scenario. However, the results of long-term outcomes of (C)TRA are scarce in the literature, due to the rarity of such cases. The relative paucity of data prompts careful review of the available relevant series in order to critically evaluate this surgical technique from the oncologic and functional points of view. A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement on the PubMed, Scopus, and Web of Science databases. English-language surgical series published between January 1985 and August 2021, reporting data on ≥5 patients treated for TC infiltrating the airway by (C)TRA were included. Oncologic outcomes, mortality, complications, and tracheotomy-dependency rates were assessed. Pooled proportion estimates were elaborated for each end-point. Thirty-seven studies were included, encompassing a total of 656 patients. Pooled risk of perioperative mortality was 2.0%. Surgical complications were reported in 27.0% of patients, with uni- or bilateral recurrent laryngeal nerve palsy being the most common. Permanent tracheotomy was required in 4.0% of patients. Oncologic outcomes varied among different series with 5- and 10-year overall survival rates ranging from 61% to 100% and 42.1% to 78.1%, respectively. Five- and 10-year disease specific survival rates ranged from 75.8% to 90% and 54.5% to 62.9%, respectively. Therefore, locally advanced TC with airway invasion treated with (C)TRA provides acceptable oncologic outcomes associated with a low permanent tracheotomy rate. The reported incidence of complications, however, indicates the need for judicious patient selection, meticulous surgical technique, and careful postoperative management.

Outcomes of Tracheal Resections in Well-Differentiated Thyroid Cancer-A case series and meta-analysis

BACKGROUND

Tracheal invasion in thyroid cancer is a well-known form of advanced disease. There is an ongoing controversy over outcomes of tracheal shaving in this situation. The aim of this study was to compare the results of tracheal shaving to radical resections in patients with low-volume tracheal involvement.

METHODS

An institutional case series and a meta-analysis was conducted. All studies that included patients diagnosed with well-differentiated thyroid cancer (WDTC) and tracheal invasion were analyzed. Patients with low-volume tracheal invasion (according to the Shin classification) were extracted from the various studies and subsequently included in this study. The outcomes of tracheal shaving and radical resection were consolidated and compared. All recurrences and mortality over 10 years of follow-up were calculated using the Kaplan-Meier method.

RESULTS

Institutional case series included 22 patients diagnosed with WDTC and tracheal invasion that underwent resection. There was one case of recurrence (4.5%) during the follow-up period and no mortality. The meta-analysis yielded a total of 284 patients from six studies who met the inclusion criteria. The 10-year overall survival was 82.4% for the shave group and 80.8% for the resection group. The combined Kaplan-Meier curves revealed no statistically significant difference between the two techniques (hazard ratio [HR] = 0.86, P = .768). The combined 10-year local control rate of the shave group was 90.2%.

CONCLUSIONS

The outcomes of tracheal shaving in low-volume invasion are similar to more aggressive forms of tracheal resections. Shave resection is oncologically safe in carefully selected WDTC patients demonstrating minimal tracheal invasion.

Surgical Management of Tracheal Invasion by Well-Differentiated Thyroid Cancer

Simple Summary

Tracheal invasion is a poor prognostic factor in well-differentiated thyroid cancer. Appropriate resection can improve the prognosis and maintain the patient’s quality of life. Shaving resection for superficial tracheal invasion is minimally invasive because it does not involve the tracheal lumen, despite the problematic risk of local recurrence. Window resection for tracheal mucosal and luminal invasion provides good tumor control and does not cause postoperative airway obstruction; however, the need for surgical closure of the tracheocutaneous fistula is a disadvantage of this method. Circumferential (sleeve) resection and end-to-end anastomosis are highly curative, but the risk of fatal complications, such as anastomosis dehiscence, is a concern.

Abstract

Well-differentiated thyroid carcinoma (WDTC) is a slow-growing cancer with a good prognosis, but may show extraglandular progression involving the invasion of tumor-adjacent tissues, such as the trachea, esophagus, and recurrent laryngeal nerve. Tracheal invasion by WDTC is infrequent. Since this condition is rare, relevant high-level evidence about it is lacking. Tracheal invasion by a WDTC has a negative impact on survival, with intraluminal tumor development constituting a worse prognostic factor than superficial tracheal invasion. In WDTC, curative resection is often feasible with a small safety margin, and complete resection can ensure a good prognosis. Despite its resectability, accurate knowledge of the tracheal and peritracheal anatomy and proper selection of surgical techniques are essential for complete resection. However, there is no standard guideline on surgical indications and the recommended procedure in trachea-invading WDTC. This review discusses the indications for radical resection and the three currently available major resection methods: shaving, window resection, and sleeve resection with end-to-end anastomosis. The review shows that the decision for radical resection should be based on the patient’s general condition, tumor status, expected survival duration, and the treating facility’s strengths and weaknesses.

Oncologic and functional outcomes following laryngectomy for locally advanced thyroid cancer

BACKGROUND AND OBJECTIVES

Total laryngectomy in thyroid cancer is controversial. Functional and oncologic outcomes are needed to inform surgical indications in this population.

METHODS

A retrospective cohort study was performed at a tertiary referral center from 1997 to 2018 to identify patients with a diagnosis of thyroid carcinoma who underwent total laryngectomy. Complications, survival outcomes, and functional outcomes were analyzed.

RESULTS

Thirty patients met the inclusion criteria. The mean age was 62 years (range, 30-88 years) and the male-to-female ratio was 1:2.75. The most common diagnosis was well-differentiated thyroid cancer (53.3%), followed by poorly differentiated (30%) and anaplastic (16.7%). Total laryngectomy was performed with a 10% rate of Clavien-Dindo Grade III-V complications. The median overall survival was 40 months (range, 1-237). Five-year overall survival was 39.5% and disease-specific survival was 51.1%. Locoregional control was achieved in 80.0% of patients. Twelve months postoperatively, 100% of surviving patients were taking oral intake and 86.4% had a self-reported functional voice.

CONCLUSION

Total laryngectomy for locally advanced thyroid cancer is safe and provides acceptable rates of locoregional control. While the risk of distant metastases remains high, advances in systemic therapy may justify aggressive local control strategies to improve the quality of life.

Tracheal/Laryngeal Infiltration in Thyroid Cancer: a Single-Centre Experience

Around 1/3 of patients of locally advanced carcinoma thyroid present with tracheal infiltration either alone or along with infiltration of other adjacent structures. Even though trachea is infiltrated, adequate resection is the main modality of treatment in these patients. We retrospectively analysed carcinoma thyroid patients who were operated at our institute, between January 2011 and December 2018, and underwent thyroidectomy with tracheal or laryngeal resection. Seventeen patients underwent tracheal/laryngeal resection with thyroidectomy. The mean age of patients was 57 years. Six and eleven were male and female, respectively, 0.14 (82%) patients had dyspnoea on presentation, 6 had hoarseness of voice, 6 had haemoptysis, and in 2 patients, neck swelling was the only complain. Two patients in our study presented with acute stridor, underwent emergency intubation and subsequently surgery. Two other patients had bulky pedunculated tumour in preoperative bronchoscopy and required tracheostomy for intubation before proceeding with surgery. In 11 patients, sleeve resection followed by end-to-end anastomosis was done, window resection was done in 3 patients, partial laryngectomy in 1, and total laryngectomy in 2 patients. In 10 patients (59%), the site of infiltration was in the lateral tracheal wall, with relatively small posterior primary (mean size 3.7 cm) in the thyroid lobe. Two patients developed postoperative complication, one patient with sleeve resection had secondary haemorrhage, and one patient who underwent window resection with myochondrial thyroid lamina flap reconstruction developed salivary fistula. These patients underwent re exploration with tracheostomy and were subsequently decannulated. Preoperative diagnosis of tracheal infiltration helps in better planning of surgery and counseling the patients of any possible complication. Clinical workup and pre-emptive diagnosis is therefore of paramount importance.

Complications from tracheal resection for thyroid carcinoma

Thyroidectomy associated to en bloc tracheal resection with end-to-end anastomosis is the treatment of choice of thyroid tumor invading the tracheal wall and is associated with a good prognosis. However, the postoperative morbidity is not irrelevant. The present review aims to discuss the complications occurring after this aggressive surgical procedure. The search was performed using PubMed through an overarching for the following terms: "complication of tracheal resection [AND] invasive thyroid cancer". Postoperative complications rate after tracheal sleeve resection with end-to-end anastomosis for thyroid cancer invading tracheal wall range from 15% to 39%. Postoperative mortality is about 1.2%. The most common postoperative complications are: anastomotic dehiscence, airway stenosis, infections and bleeding. Tumor local recurrence can be considered a late on set complication. To conclude, in locally invasive thyroid cancer, en bloc resection of the thyroid with the tracheal segment interested by the tumor provides a good prognosis despite the non-negligible postoperative morbidity rate. Patients' selection and accurate surgical technique performing a tracheal tension-free anastomosis are mandatory to reduce postoperative morbidity and mortality.

Surgical Management of Cricotracheal Invasion by Papillary Thyroid Carcinoma

BACKGROUND

In general, patients with papillary thyroid carcinoma (PTC) have an excellent postoperative prognosis. Those with cricoid and/or tracheal PTC invasion, however, are at a higher risk of postoperative morbidity and airway insufficiency.

METHODS

We investigated postoperative airway outcomes, locoregional recurrence, and survival rates in patients with PTC who underwent cricotracheal resection. The records of PTC patients who underwent surgery at our institution between 1981 and 2009 were reviewed retrospectively, and 110 patients with cricotracheal invasion were enrolled. Curative resection was performed in all patients, and cricotracheal function was preserved or reconstructed when possible.

RESULTS

Of the 110 patients, 57 and 53 patients had superficial and intraluminal invasion of the larynx, respectively. After the initial surgery, the 10-year disease-specific survival rates were 90.8 and 44.4 % in patients with superficial and intraluminal invasion of the cricotracheal area, respectively. Only six patients (5.5 %) had an isolated upper aerodigestive tract recurrence. Five patients were managed with an additional window resection as salvage surgery. Consequently, only one patient (0.9 %) underwent total laryngectomy. Altogether, 31 patients (28.0 %) had a permanent stoma, 9 and 15 of which were caused by cricotracheal invasion and invasion of other aerodigestive structures, respectively.

CONCLUSIONS

Window resection for intraluminal cricotracheal invasion by PTC produced good surgical outcomes that resulted in a low local recurrence rate and survival rates that resembled those associated with other surgical treatments. Treatment of multiple organ invasion of the aerodigestive tract was necessary to improve postoperative functional outcomes in these patients.

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.

Resection margins and prognosis in locally invasive thyroid cancer

BACKGROUND

Invasive thyroid cancer is rare, and the extent of surgery controversial. The purpose of this study was to present and evaluate therapeutic prognostic factors.

METHODS

We conducted a retrospective single-center study of differentiated thyroid carcinoma invading the larynx, trachea, and/or esophagus treated surgically with macroscopic complete resection.

RESULTS

Forty-six patients (average age, 57 years; average follow-up, 4 years) were included. Free margins (R0) were obtained for 22 of 46 (49%) and microscopic residual tumor was present after surgery (R1) for 24 (51%). Ten-year actuarial local control was 100% for R0 and 75% for R1 (p = .08). Five-year local control was lower for recurrent tumors versus inaugurally invasive disease (63% vs 87%; log-rank p = .011). Five-year and 10-year actuarial disease-specific survival (DSS) was correlated with preoperative distant metastases (100% and 87%, respectively, for M0 vs 68% and 34% for M1; p = .01).

CONCLUSION

A trend toward lower local control was observed for R1 versus R0. The morbidity of surgery should be weighed against the prognosis if metastases are present.

Recombinant human thyrotropin-aided radioiodine therapy in tracheal obstruction by an invading well-differentiated thyroid carcinoma

Papillary thyroid carcinomas (PTCs) usually extend to lymph nodes in the neck and mediastinum. Rarely, they invade the neighboring upper airway anatomical structures. We report a 56-year-old woman who presented with symptoms of upper airway obstruction. Imaging studies revealed a lesion derived from the thyroid which invaded and obstructed the trachea, which appeared to be a highly differentiated PTC. Total thyroidectomy was performed, with removal of the endotracheal part of the mass along with the corresponding anterior tracheal rings. Two months later, a whole body I(131) scan after recombinant human thyroid-stimulating hormone (rh-TSH) administration was performed and revealed a residual mass in upper left thyroid lobe. Subsequently, 150 mCi I(131) were given following rh-TSH administration. Nine months later, there was no sign of residual tumor. This case is the first one reported in the literature regarding rh-TSH administration prior to RAI ablation in a PTC obstructing the trachea.

Prognosis and management of invasive well-differentiated thyroid cancer

Invasive thyroid cancer is often asymptomatic and can take the surgeon and the patient by surprise. Maintenance of a high level of suspicion in patients who present with symptoms, an abnormal examination, recurrent disease, or documented metastatic disease lead the clinician to obtain appropriate cross-sectional imaging that helps to define the full extent of the disease. Specific guidelines are provided for the management of the various structures in the neck that are at risk for involvement by disease extension outside the gland or extracapsular extension outside a lymph node with involvement by metastatic disease. This article reviews the prognosis, diagnosis, management, and implications of invasive thyroid cancer affecting the various structures of the central and lateral compartments of the neck.

The management of thyroid carcinoma invading the larynx or trachea

OBJECTIVES/HYPOTHESIS

To describe the controversies in the management of thyroid carcinoma invading the airway.

STUDY DESIGN

Contemporary review of literature; level of evidence: 5.

RESULTS

Invasion of the larynx or trachea by thyroid carcinoma is uncommon and often identified at the time of operation, when the surgeon must decide the extent of resection. Invasion of the airway is associated with loss of tumor differentiation and a reduction in long-term survival compared to tumors limited to the thyroid gland. Whether or not the invaded airway should be resected remains controversial. Tangential shave excision of tumor is commonly performed, despite a marked risk of local recurrence. Circumferential sleeve resection of the larynx and trachea is safe and lowers the risk of local recurrence. In recurrent disease, laryngotracheal resection provides effective palliation of airway obstruction and hemoptysis.

CONCLUSIONS

Long-term (>10-20 years) prospective studies are required to compare the outcome after shave excision with segmental airway resection for thyroid carcinoma. Based on the current literature and on our experience, we advocate circumferential tracheal resection in the setting of airway involvement.

Surgical management of tracheal shaving for papillary thyroid carcinoma with tracheal invasion

CONCLUSION

Patients showed improved quality of life following tracheal shaving and the carcinoma was well controlled locally, as long as invasion had not progressed to the mucosal surface of the trachea. However, compared with papillary thyroid carcinoma (PTC) with no tracheal invasion, metastasis was common and invasion of organs other than the trachea was frequent, putting many patients into the high-risk group. The clinical course for such patients thus requires careful monitoring, with particular attention to metastasis to other locations. Tracheal shaving can be recommended for patients with PTC with tracheal invasion.

OBJECTIVES

Macroscopically, in cases where invasion into the trachea has not reached the tracheal mucosa surface, we perform tracheal surface resection (tracheal shaving). We retrospectively investigated rates of local control, metastasis and survival in patients who had undergone tracheal shaving.

PATIENTS AND METHODS

Subjects comprised 22 patients with PTC who underwent tracheal shaving between January 1994 and December 2005.

RESULTS

Local control was achieved in 21 patients (95%), and metastasis was seen in 6 patients (27%). With two patients dying from causes other than cancer, 5- and 10-year survival rates were 93% and 41%, respectively. The two surviving patients are still cancer-bearing.

Invasive thyroid cancer: management of the trachea and esophagus

Well-differentiated thyroid cancer most commonly presents as an intrathyroidal tumor; however, extrathyroidal extension occurs in approximately 6% to 13% of patients and carries a significant negative impact on survival. Extrathyroidal disease may involve critical structures in the central neck, including the recurrent laryngeal nerves, trachea, esophagus, and larynx, requiring surgery extending significantly beyond the thyroid gland. Appropriate surgical management is of great importance and can normalize survival curves, whereas gross residual disease postoperatively may lead to recurrence and decreased survival. Adjuvant postoperative therapies for thyroid cancers with extrathyroidal extension include thyroid hormone suppression, radioactive iodine therapy, and external beam radiotherapy. This summary reviews approaches to the management of invasive thyroid cancers involving the aerodigestive tract.

Management of locally invasive well-differentiated thyroid cancer

Thyroid carcinoma invasion of the aerodigestive tract and recurrent laryngeal nerve (RLN) are important factors with increase in morbidity and mortality. Primary treatment is surgery; the decision about the extent of surgery is difficult, because preserving function is as essential as removal of the tumor. This article discusses the literature relating to the assessment of disease, surgical management, and adjuvant therapy for invasive thyroid cancer of the aerodigestive tract and RLN and makes suggestions based on the authors' experience.

Segmental Laryngotracheal and Tracheal Resection for Invasive Thyroid Carcinoma

BACKGROUND

Laryngotracheal invasion worsens prognosis in patients with thyroid carcinoma. The extent of resection is controversial.

METHODS

We performed a retrospective study of patients with thyroid carcinoma and invasion of the larynx or trachea between 1964 and 2005.

RESULTS

Eighty-two patients, mean age 64 years and 50% female, underwent segmental airway resection. Differentiated carcinoma was present in 76% (62 of 82 patients), prior tracheal "shave" procedures in 40% (33 of 82 patients), transmural invasion in 58% (48 of 82 patients), and preoperative vocal cord paralysis in 35% (29 of 82 patients). There were 29 tracheal and 40 laryngotracheal resections (reconstruction group: 69 patients); 5 underwent laryngectomy, 7 cervical exenteration, and 1 tracheal resection after exenteration (salvage group: 13 patients). Operative mortality was 1.2% (1 of 82 patients) and anastomotic dehiscence 4.3% (3 of 69 patients). Tracheostomy was permanent in 4.3% (3 of 69 patients). Mean follow-up was 6.1 years. After reconstruction, mean survival was 9.4 years and 10-year survival was 40%; after salvage, these were 5.6 years and 15%, respectively. In differentiated carcinoma, thyroidectomy, immediate shave procedure, and delayed (mean, 67 months) resection of airway recurrence in 15 patients resulted in overall and disease-free survival of 13.1 and 5.1 years, respectively, compared with 17.9 and 14.6 years, respectively, after thyroidectomy and early airway resection in 11 patients. Airway symptoms, metastases at presentation, recurrent disease, and salvage operation were associated with decreased survival; airway resection early after thyroidectomy, complete resection, and well-differentiated tumors were associated with improved prognosis.

CONCLUSIONS

Segmental airway resection for invasive thyroid cancer is safe, preserves the voice, and relieves airway obstruction. Complete resection of laryngeal and tracheal invasion during or early after thyroidectomy is associated with improved survival.

Thyroid cancer invasion of neck structures: epidemiology, evaluation, staging and management

PURPOSE OF REVIEW

This review addresses the issue of direct extra-capsular invasion of thyroid cancer; this may occur in several ways and to varying degrees. The evidence regarding the prognostic and treatment implications of extra-thyroidal spread is examined. The phenomenon is most common in papillary carcinoma of the thyroid and that is the focus for this review. Less common, but more aggressive tumours (medullary and anaplastic carcinoma) are not considered here.

RECENT FINDINGS

Overall, around 15% of thyroid cancers exhibit extra-thyroid spread but the rate is much higher in specific subgroups. The presence of invasive disease affects the staging of the tumour, and the implications for surgery can be substantial if complete tumour extirpation is to be achieved. No particular examination is completely accurate in detecting extra-thyroid spread preoperatively. Invasion posteriorly carries greater morbidity and mortality than anterior spread. The presence of extra-thyroid spread usually warrants adjuvant radiotherapy (radioiodine or external beam).

SUMMARY

Histologic assessment is the gold standard for detecting invasive thyroid cancer. Thyroidectomy is effectively a staging procedure by which the presence and extent of invasive disease can be established and subsequent management determined. Extra-thyroidal spread influences morbidity and mortality.

Clinical outcome of different modes of resection in papillary thyroid carcinomas with laryngotracheal invasion

AIM

The aim of this study is to evaluate the outcome of different modes of resection in papillary thyroid carcinoma (PTC) with laryngotracheal invasion.

MATERIALS AND METHODS

Sixty-four primary PTCs with laryngotracheal invasion between 1964 and 2003 were retrospectively analyzed (17 men and 47 women; mean age, 61.6 years; mean follow-up, 92.3 months). Thirteen curative resections included six pharyngolaryngoesophagectomies, two total laryngectomies, and five circumferential resections (complete surgery). Eighteen patients who were candidates for curative resection refused to undergo complete surgery to avoid functional impairment, especially laryngeal function (incomplete surgery). Thirty-three patients with minimal invasion underwent shave or partial resection (conservative surgery). Clinical outcomes were compared between the three groups. The influence of different types of surgery and invasion was also evaluated by Cox proportional hazard analysis.

RESULTS

Three (23.1%) complete, 17 (94.4%) incomplete, and 4 (13.8%) conservative surgery patients died of disease (P < 0.0001). The 10-year disease-specific survival (Kaplan-Meier) in complete, incomplete, and conservative surgery patients were 62.9, 11.1, and 87.7%, respectively (log rank test, P < 0.0001). Incomplete surgery related to worse prognosis [p < 0.0001; hazard ratio (HR), 12.9) than complete or conservative surgery. Tracheal deep invasion (p = 0.0019, HR 7.6) and larynx invasion (p < 0.0001, HR 9.9) related to worse prognosis than minimal invasion.

CONCLUSION

Curative resection improves clinical outcomes in PTCs with laryngotracheal invasion. Conservative resection for minimal invasion also can achieve favorable prognosis. The degree of tumor invasion is significantly related to survival.

The role of postoperative external-beam radiotherapy in the management of patients with papillary thyroid cancer invading the trachea

PURPOSE

To determine the role of adjuvant external-beam radiotherapy (EBRT) in the management of patients with well-differentiated thyroid cancer invading the trachea.

METHODS AND MATERIALS

Of 1,098 thyroid cancer patients, 68 (6%) were found to have tracheal invasion, and they all received "shave" excision of the tracheal cartilage. Among them, 12 patients had no postoperative residuum, 43 patients had microscopic residuum, and 13 patients had macroscopic residuum. All patients were divided into two groups according to treatment modality with or without EBRT; (1) the control group (n = 43) and (2) the EBRT group (n = 25).

RESULTS

The locoregional recurrence rate for EBRT patients was much lower than that of control patients (51% for the control group vs. 8% for the EBRT group) (p < 0.01). The 10-year local progression-free survival rate for the EBRT group was significantly better than that of the control group (89% in the EBRT group vs. 38% in the control group) (log-rank, p < 0.01). The use of adjuvant EBRT after conservative surgery was an independent prognostic factor in univariate and multivariate analyses.

CONCLUSIONS

External-beam radiotherapy was found to be effective, particularly in patients with thyroid cancer invading the trachea with microscopic or gross residuum after conservative surgery.

[Differenciated thyroid carcinomas with laryngo-tracheal invasion]

OBJECTIVES

Analyze the diagnosis and treatment of differentiated thyroid carcinomas with laryngo-tracheal invasion.

MATERIALS AND METHODS

Among the 117 patients operated for a differentiated thyroid carcinoma in the ENT department of Tours Hospital (France) between January 1990 and December 2003, seven presented laryngo-tracheal invasion and were included in this retrospective study.

RESULTS

Laryngo-tracheal resection resulted in a thyroid cartilage-shaving in two patients. We performed a resection of one side of the thyroid cartilage in one patient, a thyro-tracheal resection-anastomosis with a partial cricoidectomy in one patient, a partial vertical laryngectomy extended to the first tracheal ring in one patient and a total laryngectomy in one patient. No laryngo-tracheal resection was done in one patient. Early complications were swallowing disorders (n = 2), transitory hypoparathyroidism (n = 1), definitive recurrent nerve paralysis (n = 2), subcutaneous emphysema and hematoma (n = 1) and Claude Bernard-Horner's syndrome (n = 1). Locoregional recurrences (n = 2) and distant metastasis (n = 2) were discovered six months to four years after the laryngo-tracheal resection. With a mean follow-up of 40 month, four patients were alive (two disease free) two patients had died and one was lost of follow-up at three months.

CONCLUSION

The frequency of locoregional recurrences and distant metastasis is higher for the differentiated thyroid carcinomas with laryngo-tracheal invasion than the others. In these cases, we performed macroscopic carcinological surgery preserving laryngeal functions as much as possible.

Aerodigestive Tract Invasion by Well-Differentiated Thyroid Carcinoma: Diagnosis, Management, Prognosis, and Biology

OBJECTIVES/HYPOTHESIS

1) To describe the clinical entity invasive well-differentiated thyroid carcinoma (IWDTC), 2) to determine prognostic factors for survival in patients with IWDTC, 3) to describe and compare types of surgical resection to determine treatment efficacy, 4) to offer a staging system and surgical algorithm for management of patients with IWDTC, 5) to examine alterations in expression of E-cadherin and beta-catenin adhesion molecules in three groups of thyroid tissue and propose a cellular mechanism for invasion of the aerodigestive tract.

STUDY DESIGN

Basic science: quantification of expression of E-cadherin and beta-catenin in three groups of thyroid tissue. Clinical: retrospective review of patients with IWDTC surgically treated and followed over a 45-year time period.

METHODS

Basic science: immunohistochemical staining was used with antibodies against E-cadherin and beta-catenin in three groups of tissue: group 1, normal control thyroid tissue (n = 10); group 2, conventional papillary thyroid carcinoma (n = 20); group 3, IWDTC (n = 12). Intensity scores were given on the basis of protocol. One-way analysis of variance (ANOVA) was used to evaluate differences between groups. Post hoc ANOVA testing was completed. P < .05 was significant. Clinical: patients were divided into three surgical groups within the laryngotracheal subset: group 1, complete resection of gross disease (n = 34); group 2, shave excision (n = 75); group 3, incomplete excision (n = 15). Cox regression analysis was used to determine significance of prognostic factors. Kaplan-Meier plots were used to evaluate survival. P < .05 was significant.

RESULTS

Basic science: a significant difference between the three thyroid tissue groups for E-cadherin expression was demonstrated on one-way ANOVA testing. When controls were compared with either experimental group in post hoc ANOVA testing, differences between all groups were demonstrated (P < .001). For beta-catenin, the intensities of the three groups were not different by one-way ANOVA testing. Similar nonsignificant results were found on post hoc ANOVA testing. Clinical: there was a statistically significant difference in survival for patients with and without involvement of any portion of the endolarynx or trachea (P < .01). There was a significant difference among all three surgical groups when compared (P < .001). When complete and shave groups were compared with gross residual group there was a significant decrease in survival in incomplete resection group (P < .01). Cox regression analysis demonstrated invasion of larynx and trachea were significant prognostic factors for poor outcome. The type of initial resection was significant on multivariate analysis. Removal of all gross disease is a major factor for survival.

CONCLUSIONS

Basic science: there is a decrease in membrane expression of E-cadherin in IWDTC, and loss of this tumor suppressor adhesion molecule may contribute to the invasive nature of well-differentiated thyroid carcinomas. Clinical: laryngotracheal invasion is a significant independent prognostic factor for survival. Patients undergoing shave excision had similar survival when compared with those undergoing radical tumor resection if gross tumor did not remain. Gross intraluminal tumor should be resected completely. Shave excision is adequate for minimal invasion not involving the intraluminal surfaces of the aerodigestive tract.

Ultrasonography as a Method of Screening for Tracheal Invasion by Papillary Thyroid Cancer

PURPOSE

To assess the reliability of ultrasonography (US) for detecting tracheal invasion by papillary thyroid cancer (PTC).

METHODS

We reviewed the clinical and surgical data of 509 patients who underwent surgery for primary PTC during 2003, after routine preoperative US.

RESULTS

Ultrasonography showed possible tracheal invasion in 43 of the 509 patients. However, the US findings could not be evaluated in 32 patients because of high tumor calcification, a tumor diameter greater than 4 cm, or tumor extension inferior to the clavicle. We shaved the tracheal wall in 11 patients and resected the tracheal wall in 2 patients. The sensitivity of US for diagnosing of tracheal invasion was 91%, the specificity 93%, the predictive value of a positive test 25%, the predictive value of a negative test 99%, and the accuracy 93%.

CONCLUSION

Ultrasonography is a useful method of screening for tracheal invasion. A negative sonogram is a reliable indicator of the absence of tracheal invasion, except when tumors are highly calcified or extend inferior to the clavicle.

Management of the locally aggressive thyroid carcinoma

The management of locally advanced thyroid carcinoma can be challenging. Differing philosophies exist for the treatment of invasive disease affecting the upper aerodigestive tract. The ability to maximize local control and overall survival while minimizing the morbidity of a radical resection is the goal of care in these patients. This article will review the literature concerning the presentation, preoperative evaluation, and the subsite treatment of locally aggressive well-differentiated thyroid carcinoma.

Recurrent laryngeal nerve palsy in well-differentiated thyroid carcinoma: clinicopathologic features and outcome study

Involvement of the recurrent laryngeal nerve (RLN) by well-differentiated thyroid carcinoma may not invariably lead to unilateral cord palsy, although the presence of RLN palsy is associated with locally advanced disease. The present study evaluates the clinicopathologic features and outcomes of patients surgically treated for well-differentiated thyroid carcinoma with documented nonfunctioning RLN at presentation. From 1970 to 2002, 20 of 709 patients undergoing surgical treatment for well-differentiated thyroid carcinoma were found to have ipsilateral unilateral cord palsy by routine preoperative laryngoscopy. There were 5 men and 15 women with a median age of 70 years. Nine patients (45%) did not have a clinically palpable thyroid mass, and hoarseness was the primary presenting symptom. All patients had histologically confirmed pT4 papillary thyroid carcinoma with a median size of 4 cm. Cervical nodal and pulmonary metastases were detected in 14 (70%) and 2 (10%) patients, respectively. The ipsilateral recurrent nerve was transected in all patients because of gross tumor involvement, and 19 patients underwent total or completion total thyroidectomy. Resection was incomplete in 15 patients, including 2 who underwent a debulking procedure and required reoperation for local control. Postoperative radioactive iodine ablation and external-beam irradiation were administered to 18 and 13 patients, respectively. Over a median follow-up of 4.5 years, 10 patients survived without evidence of recurrence, 5 died of disease recurrence, and 5 died of unrelated causes. The 5-year and 10-year cause-specific mortality was 17% and 42%, respectively. Patients developing distant metastasis at presentation or during follow-up had a significantly increased cause-specific mortality (p = 0.002). Preoperative RLN palsy can be the first symptom in patients with locally advanced papillary thyroid carcinoma. Despite the adoption of a relatively conservative surgical treatment, long-term survival can be achieved in selected patients.

Locally advanced differentiated thyroid cancer

Although most patients with differentiated thyroid cancer (DTC) of follicular cell origin enjoy a relatively good prognosis, some patients unfortunately present with or develop locally advanced DTC which leads to significant local morbidity and mortality. DTC accounts for 54-94% of all locally advanced thyroid cancers. DTC invasion of the recurrent laryngeal nerve, strap muscles and trachea are the most common followed by invasion of the esophagus, internal jugular vein and carotid artery. Surgical resection is the primary treatment for locally advanced DTC. Although the optimal surgical approach (ranging from conservative shave excision to aggressive en bloc resection of tumor and vital structures) in patients with locally advanced DTC is controversial, a curative resection should be the goal unless complete tumor resection results in unwanted perioperative morbidity and mortality or widely metastatic disease is present. Postoperative radioiodine ablation with TSH suppression is imperative after surgical resection of locally advanced DTC. Patients with microscopic or small gross residual disease, after surgical resection, may benefit from postoperative external radiotherapy for local control of disease.

Surgical management of thyroid carcinoma invading the trachea

Airway invasion by thyroid carcinoma is an uncommon but important clinical problem. The surgical management of airway invasion is somewhat controversial, with some studies suggesting that conservative shave procedures might be adequate; however, the standardization and safety of techniques of airway resection and reconstruction have made en bloc surgery a reasonable approach for the management of such carcinomas. Tracheal resection and reconstruction for thyroid carcinomas with airway invasion might provide long-lasting palliation and might even be curative in a significant number of patients suffering from this disease.

Using MR imaging to predict invasion of the recurrent laryngeal nerve by thyroid carcinoma

OBJECTIVE

We evaluated the accuracy of MR imaging findings for predicting invasion of the recurrent laryngeal nerve by thyroid carcinoma and established an optimal criterion on which to base this prediction.

MATERIALS AND METHODS

We reviewed MR imaging findings (lesion size and posterior extension of tumor; encirclement of and invasion into the laryngeal cartilage, trachea, and esophagus by the tumor; and the amount of effaced fatty tissue in the tracheoesophageal groove or between the laryngeal cartilage and hypopharyngeal wall) in 66 patients with thyroid carcinoma. The amount of effaced fatty tissue was classified as one of five grades: 1, normal amount of fatty tissue; 2, partly effaced; 3, completely effaced in one MR imaging slice; 4, completely effaced in two contiguous MR slices; and 5, completely effaced in three or more contiguous MR slices.

RESULTS

Thirty-two (48%) of the 66 patients had surgically or pathologically verified recurrent laryngeal nerve invasion. Logistic modeling revealed that the amount of effaced fatty tissue (p < 0.001) and the lesion size (p = 0.033) were the significant factors. Using the threshold values for the lesion size to predict invasion, we found that a threshold of more than 2.9 cm showed the highest accuracy, 76%, with 78% sensitivity and 74% specificity. For the amount of effaced fatty tissue, a grade of 3 or more had the highest accuracy, 88%, with 94% sensitivity and 82% specificity. Addition of the lesion size to this criterion did not improve the diagnostic accuracy of using the amount of effaced fatty tissue alone.

CONCLUSION

Invasion of the recurrent laryngeal nerve by thyroid carcinoma was accurately predicted by the finding of effaced fatty tissue on MR imaging.

Esophageal invasion by thyroid carcinomas: prediction using magnetic resonance imaging

PURPOSE

We evaluated the accuracy of magnetic resonance imaging (MRI) in predicting esophageal invasion by thyroid carcinomas and established an optimal criterion for diagnosing esophageal invasion.

METHOD

The MRI findings (size and margins of tumor, ratio of tumor contact to the esophagus, shape and displacement of the esophagus, and tumor invasion to the outer and inner layers of the esophagus) in 67 patients with thyroid carcinomas were retrospectively reviewed and correlated with surgical and pathologic findings. Logistic modeling was used to determine the significant factors for predicting esophageal invasion.

RESULTS

Seventeen (34%) of the 67 patients had pathologically or surgically verified esophageal invasion. The logistic modeling revealed that outer layer invasion (P < 0.001) and poorly defined margins (P = 0.001) were the significant factors. The outer layer invasion showed the highest accuracy of 91%, with 82% sensitivity and 94% specificity. The addition of poorly defined margins to this criterion did not improve its accuracy.

CONCLUSION

Esophageal invasion by thyroid carcinoma was accurately predicted with MRI, and an MRI finding of outer layer invasion was optimal for diagnosing esophageal invasion.

Results of the treatment of locally invasive thyroid carcinoma

BACKGROUND

Well-differentiated thyroid carcinoma usually has an excellent prognosis. However, when extrathyroidal invasion occurs, it is associated with significant morbidity and mortality. This report presents the experience of a single institution in the treatment of patients with locally invasive, well-differentiated thyroid carcinoma.

PATIENTS AND METHODS

Forty-six patients with locally invasive well-differentiated thyroid carcinoma were diagnosed. Histopathologic types included: 28 papillary carcinoma and 18 follicular.

RESULTS

Patients with exclusive invasion of the muscle or recurrent laryngeal nerve usually had complete tumor resection. Patients with tracheal, laryngeal, or esophageal invasion usually underwent shave resection. The factors that adversely affected survival were: age >45 years, preoperative diagnosis of extrathyroidal extension, and incomplete resection (p <.05).

CONCLUSIONS

There were similar survival results after complete or shave resection and poor survival when the resection was incomplete. Tumors with minimal invasion can be treated by shave resection with acceptable survival and low morbidity.

Prognostic significance of magnetic resonance findings in advanced papillary thyroid cancer

We assessed the prognostic importance of magnetic resonance (MR) findings in locally advanced papillary thyroid cancer. MR findings, clinical data, and pathologic (and surgical) data for 66 patients, including 51 women and 15 men with a mean age of 57 years, who had primary surgery for papillary thyroid cancers were correlated with prognosis. Mean follow-up was 27.5 months (range, 5-117 months). Recurrence was seen in 18 patients (27%). In univariate analyses, age of 60 years or more (p = 0.0066), male gender (p = 0.0373), six MR findings (tumor size of > or = 4 cm ([p = 0.0002], ill-defined margins ([p < 0.0001], tumor extension of the trachea [p = 0.0337], carotoid artery [p = 0.0028]), esophagus [p < 0.0001], and lymph nodes [p = 0.0005]), and three pathologic findings (tumor extension of soft tissues [p = 0.0288], carotid artery [p = 0.0013], and esophagus [p < 0.0001]) had a significant adverse effect on disease-free survival. In multivariate analyses, tumor size (p = 0.0169) and nodal metastasis (p = 0.0393) determined on MR imaging and pathologic esophageal invasion (p = 0.0016) were the only significant independent variables. Esophageal invasion was accurately diagnosed with MR imaging (94% accuracy). MR findings may contain prognostic importance of locally advanced papillary thyroid cancer.

Tracheal invasion by thyroid carcinoma: prediction using MR imaging

OBJECTIVE

The purpose of this study was to evaluate the accuracy of MR imaging in predicting tracheal invasion by thyroid carcinomas and to determine MR imaging criteria for diagnosing tracheal invasion.

MATERIALS AND METHODS

MR imaging was performed on the normal trachea of one cadaver and 30 healthy subjects as a standard of reference. Then, MR imaging findings in 67 patients with thyroid carcinoma were reviewed and correlated with surgical and pathologic findings. A logistic regression model was used to determine which MR imaging features were significant for predicting tracheal invasion.

RESULTS

Twenty-three (34%) of the 67 patients had tracheal invasion. Logistic regression model analysis revealed that significant MR characteristics for determining tracheal invasion included soft-tissue signal in the tracheal cartilage (p < 0.001), intraluminal mass (p < 0.001), and degree of tumor circumference around the trachea (p = 0.001). The highest accuracy (90%) for determining tracheal invasion was achieved using a combination of findings. A case was considered positive for tracheal invasion if there was soft-tissue signal in the cartilage, an intraluminal mass, or a tumor that abutted a circumference of the trachea of 180 degrees or greater. Using these factors resulted in seven false-positive diagnoses because soft-tissue signal in the cartilage was sometimes seen in healthy trachea. Although intraluminal mass invariably reflected deep tracheal invasion, soft-tissue signal in the cartilage rarely indicated actual cartilage invasion but rather indicated tumor extension between the cartilaginous rings.

CONCLUSION

Tracheal invasion by thyroid carcinomas can be accurately diagnosed with MR imaging, and using a combination of criteria is the most accurate method of predicting this phenomenon.

Tracheal reconstruction under tension: an experimental study in sheep

AIMS

Invasion of the trachea by thyroid cancer is a difficult problem. Circumferential resection and end-to-end reconstruction is the treatment of choice. The objective of our study was to investigate the effect of tension on tracheal healing and stenosis formation, and to ascertain the maximum tolerable tension.

METHODS

Tracheal resections of 3, 6 and 9 cm with end-to-end anastomosis were performed on 25 sheep. The intraoperative force required for approximation of the tracheal stumps was measured. Luminal stenosis was determined with the aid of computerized planimetry 1, 2, 4, 8 and 24 weeks post-operatively.

RESULTS

A gradual increase of the stenosis rate occurred with increasing tension on the anastomosis. Acceptable results were achieved in the majority of cases without release techniques or tension suture.

CONCLUSIONS

Tracheal anastomosis under tension does not always lead to disruption or separation of the anastomosis. With the additional use of release manoeuvres and tension sutures, tracheal anastomosis under tension are possible without severe stenosis. The additional use of temporary stenting needs to be elucidated.

Thyroid carcinoma invading the cervicovisceral axis: routes of invasion and clinical implications

BACKGROUND

Controversy exists about the routes of invasion (extrathyroidal versus lymphogenic extension) when differentiated carcinoma (DTC) and medullary thyroid carcinoma (MTC) invade the cervicovisceral axis (ie, larynx, trachea, esophagus).

METHODS

We carried out an institutional analysis, from November 1994 to October 1999, of 451 consecutive patients undergoing surgery for DTC and MTC.

RESULTS

Irrespective of tumor entity, carcinomas with cervicovisceral invasion (n = 34) were significantly larger and displayed higher pT categories (mainly pT4) than noninvasive carcinomas. In invasive papillary thyroid carcinoma (PTC) and MTC, the rates of positive lymph nodes were significantly higher than in noninvasive controls. When separate logistic regression analyses were fitted for laryngeal, tracheal, and esophageal invasion, extrathyroidal growth (pT4) consistently was a significant factor predictive of invasion in both DTC and MTC, with relative risks of 10.9 to 67.8. As the routes of invasion are similar in DTC and MTC, all data were pooled for multivariate analyses. Herein, the pN1 category had a significant impact only on esophageal invasion, with a relative risk of 4.7.

CONCLUSIONS

Invasion of the cervicovisceral axis is more often caused by extrathyroidal growth than by nodal metastasis. To keep nodal metastasis from encroaching onto the cervicovisceral axis, paratracheal and paraesophageal lymph nodes should be cleared from the cervicocentral compartment at the primary operation.