Osvaldo Su??rez: Often-Forgotten Father of Functional Neck Dissection (in the Non???Spanish-Speaking Literature)

Prediction model of ipsilateral level II lymph node metastasis in papillary thyroid carcinoma

OBJECTIVES

This study aimed to develop a predictive model for ipsilateral level II lymph node metastasis (LNM) in patients with papillary thyroid carcinoma (PTC) using machine learning techniques. The necessity of level II dissection in lateral neck dissection (LND) remains debated, and accurate prediction of metastasis at this level could help refine surgical decision-making and minimize unnecessary dissection.

METHODS

A retrospective review of 138 patients with PTC who underwent initial LND with curative intent was performed. Preoperative patient background and imaging findings were analysed to identify factors associated with ipsilateral level II LNM. Decision trees (DT), random forests (RF) and support vector machines (SVM) were trained using a 70:30 data split and 10-fold cross-validation. Model performance was assessed using area under the receiver operating characteristic curve (AUC) and Brier score.

RESULTS

Ipsilateral level II LNM was present in 55 patients (39.9 %); the DT model identified significant predictors: level II LNM ≥15 mm, multiple level III lymph nodes suspicious for metastases preoperatively (LNSM), superior pole extension, level III/IV LNSM <18 mm (AUC: 0.831, Brier score: 0.140). RF and SVM showed improved predictive performance (RF: AUC 0.901, Brier score 0.124; SVM: AUC 0.929, Brier score 0.110). Features of high importance in RF and SVM were similar to those in DT.

CONCLUSIONS

This study highlights the potential of machine learning-based models in predicting ipsilateral level II LNM in PTC patients and contributes to a more personalized approach to LND. The findings support the selective omission of ipsilateral level II dissection in carefully evaluated cases, which may reduce surgical morbidity without compromising oncologic outcomes.

Historical milestones in the evolution of the procedure of neck dissection

Objective

Although neck dissection has evolved to become an integral part of the surgical armamentarium for managing head and neck cancers, the manner in which the procedure has reached its present state is worth revisiting.

Data Sources

Published original articles, reviews, clinical practice guidelines, and consensus statements related to the basis, indication, and classification of the neck dissection.

Methods

This review discusses some of the critical milestones before and after the description of the procedure of neck dissection by George Crile Sr. in 1905, which eventually played a role in the evolution of this commonly performed oncosurgical procedure.

Results

Several large observational studies of the twentieth century and multicentric randomized trials at the turn of the twenty-first century have shaped neck dissection into a safe and reliable oncosurgical procedure.

Conclusions

From being a radical surgery that was done mostly in large nodal diseases for curative or palliative purposes to becoming a simple procedure that is carried out even in node-negative cases of head and neck cancers for prognostic purposes, the procedure of neck dissection has come a long way and continues to evolve.

Adequacy of Disease Control by Supraomohyoid Neck Dissection in cT1/T2 Tongue Cancer

Background: Patients affected by oral tongue squamous cell carcinoma (OTSCC) underwent a supraomohyoid neck dissection (SOHND) or modified radical neck dissection (mRND) according to the clinical nodal status (cN0 vs. cN+). We investigate whether the type of neck dissection affects survival with the presence of extranodal extension (ENE) and multiple nodal metastases (MNM). Methods: We conducted a retrospective study enrolling surgically treated patients affected by cT1/T2 OTSCC and MNM or ENE. The outcomes assessed were: overall survival (OS), disease-free survival (DFS), and neck-control- and metastases-free survival (NC-MFS). Survival curves were plotted by the Kaplan–Meier method and the log-rank test. Furthermore, we conducted a multivariable analysis with the Cox regression model. Results: We included a total of 565 patients (36% cT1, 64% cT2). Of these, 501 patients underwent a SOHND, and 64 underwent an mRND. A total of 184 patients presented rpN+, with 28.7% of these in the SOHND group and 62.5% of these in the mRND group. We identified no significant differences in OS, DFS, and NC-MFS in the whole pN+ cohort, in the MNM, and the ENE subgroups. In the multivariable analysis, the type of ND did not affect OS and DFS. Conclusions: Treating cT1-2 N0/+ tongue cancer with SOHND is oncologically safe. ENE and MNM patients do not benefit from an mRND.

Predictive modelling of level IIb lymph node metastasis in oral squamous cell carcinoma

The aim of the present study was to examine the conditions, characteristics, and risk factors of level IIb lymph node metastases in oral squamous cell carcinoma and to formulate surgical criteria for level IIb lymph node dissection. We analyzed clinical and pathological records for 541 oral squamous carcinoma patients in relation to level IIb metastasis. Univariate and multivariate analyses were performed to detect risk factors for level IIb lymph node metastasis; a predictive model was built based on multivariate analysis and tested in a validation group. Univariate and multivariate analyses using the training group indicated that level IIa metastasis and Lymphovascular permeation (LVP) were two independent risk factors for level IIb lymph node metastasis. This model was built and tested in a validation group, the area under the curve being 0.697 (P < .0.001). The model's sensitivity was 66.7% and specificity was 77.4%. Nomogram incorporating validated variables was developed for level IIb metastasis prediction. Expected survival probabilites were analysed to specify significance of model's variable on patients' overall survival and recurrence. Level IIb dissection should be performed in patients with level IIa metastasis and LVP. However, thorough consideration of the oncologic safety of omitting level IIb dissection is compulsory.

Variations in the Anatomy of Spinal Accessory Nerve and its Landmarks for Identification in Neck Dissection: A Clinical Study

Purpose

To assess the anatomy of the spinal accessory nerve (SAN), its variations and the landmark of level II B lymph nodes.

Methods

Prospective study included 50 patients from 2016 to 2018.The predictor variables were drawn from demographic details of the patients; SAN was analyzed intraoperatively with the parameters like the nerve relationship with the IJV, SCM muscle, contributions of cervical plexus and a new parameter of length from midpoint of clavicle to entry of nerve in the trapezius muscle in the lower part of neck which was studied for the first time and forms the prime identification landmark to preserve the nerve. Outcome variables were details of anatomic variations and branches and utility of these landmarks in prevention of nerve injury.

Results

Sample consisted of 38 (76%) male and 12 (24%) female patients. The SAN with respect to the IJV was dorsal in 42% patients and ventral in 58%. In 54% cases, SAN gave a branch to the SCM without penetrating the muscle and in 46% gave a branch to the SCM penetrating the muscle. SAN received contributions from the C2 root of the cervical plexus in 68%, both C2 and C3 in 54% and C3 in 50% cases. Mean length from measurements recorded between mid-line of clavicle to insertion of SAN to trapezius muscle and entry of SAN into trapezius muscle was 59 mm with variations recorded in gender and short/long neck.

Conclusion

The result of this study suggests that parameters used are simple clinical tools for identification of the SAN and its variations resulting in no nerve injury. It is prudent for the surgeon to have knowledge of sound anatomical landmarks with the variations in the SAN course which avoids morbidity and improves the quality of life.

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

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

Internal Jugular Vein Fenestration and Duplication: Anatomical Findings, Prevalence, and Literature Review

Background: Comprehensive knowledge of the internal jugular vein (IJV) regarding its anatomical variations and the pattern of its course is valuable for preventing unexpected injuries during surgical procedures or central venous access. IJV anatomical anomalies such as fenestration and duplication are rare, mainly represented by case reports, and intraoperative findings.

Objective: To present two additional cases of IJV anomalies and highlight its clinical presentation, anatomical characteristics, management, and prevalence through an extensive literature review.

Methods and Case Reports: From January 2017 to December 2018, we retrospectively collected data of 221 patients undergoing neck dissection (ND) procedures and identified two patients with IJV anomalies (fenestration and duplication) providing a clinical prevalence of ~0.9%. The IJV fenestration referred to an IJV bifurcation that reunites proximal to the subclavian vein, whereas in the IJV duplication both branches remain separated. In both of our cases, the spinal accessory nerve (SAN) crossed the window between the IJV branches.

Conclusion: Anatomical variations are more likely to be identified intraoperatively or incidentally, and due to the risk of SAN and vascular injury, special attention should be taken to identify them preoperatively in order to reduce the risk of iatrogenic injury and unexpected complications.

Robotic Neck Dissection

Management of head and neck squamous cell carcinoma necessitates a multimodal approach. The neck dissection has evolved over many years but is well established as the key surgical intervention for management of nodal disease in the neck. The open neck dissection has many varieties based on location and degree of disease but is the gold standard surgical technique. Robot-assisted neck dissections have emerged in recent years as an alternative. More research is required to establish long-term oncologic outcomes achieved with robot-assisted surgery and to assess whether cost and operative times decrease with experience.

Prognostic value of the nodal yield in head and neck squamous cell carcinoma: A systematic review

Objective

Literature analysis on the prognostic factor of the nodal yield (NY) in neck dissections (NDs), which in general surgical oncology is a strong prognosticator and quality‐of‐care marker.

Methods

We performed a systematic review of all PubMed and Embase publications until June 30, 2018 screening for data on NY as prognosticator and overall survival (OS) as outcome in patients with head and neck squamous cell carcinoma (HNSCC). Risk for bias was asserted by application of the Quality In Prognosis Studies tool.

Results

Of the 823 screened publications, 15 were included in this analysis. Five out of seven that compared NY ≥18 vs <18 as prognosticator, showed significantly improved survival if NY ≥18. Six studies used other cutoffs and three reported improved survival with each additionally harvested lymph node.

Conclusion

Increased NY in ND specimen for HNSCC, most commonly described as ≥18 lymph nodes, is associated with improved OS and could be used as a prognosticator and quality‐of‐care marker.

Standards and Definitions in Neck Dissections of Differentiated Thyroid Cancer

Papillary and follicular thyroid carcinomas arising from the follicular epithelial cells and forming differentiated thyroid cancer (DTC) consist of >95% of thyroid cancers. Lymph node metastasis to the neck is common in DTC, especially in papillary thyroid cancer. The removal of only the metastatic lymph nodes (berry picking) does not help to achieve a potential positive contribution to the survival and recurrence of lymph node dissection in the DTC. Thus, systematic dissection of the cervical lymph nodes is needed. Today, according to the widely accepted and commonly used definitions and lymph node staging, the deep lymph nodes of the lateral side of the neck are divided into five regions. Based on the fact that some groups have biologically independent regions, Groups I, II, and V are divided into the A and B subgroups. The central region lymph nodes contain VI and VII region lymph nodes, which consist of the prelaryngeal, pretracheal, and right and left paratracheal lymph node groups. Radical neck dissection (RND) is accepted as the standard basic procedure in defining neck dissections. In this method, in addition to all the regions of the Groups I-V lymph nodes at one side, the ipsilateral spinal accessory nerve, internal jugular vein, and sternocleidomastoid muscle are removed. Sparing of one or more of the routinely removed non-lymphatic structures in the RND is called modified RND (MRND), whereas the preservation of one or more of the routinely removed lymph node groups in the RND is termed as selective neck dissection (SND). In difference, the procedure with an addition of a lymph node and/or non-lymphatic structures to routinely removed neck structures in RND is called extended RND. Generally, involving one or more regions of SND are applied for DTC. The removal of the paratracheal, prelaryngeal, and pretracheal lymph node groups at one side is termed as ipsilateral central dissection, whereas the removal of the bilateral paratracheal lymph node groups, in other words, the excision of four lymph node groups in the central region (Groups VI and VII), is defined as bilateral central dissection. In conclusion, bilateral central neck dissection (CND) is the SND in which the regions of VI and VII are removed. In the DTC, CND is prophylactically and therapeutically applied, whereas lateral neck dissection is performed only therapeutically in the presence of clinical metastasis (N1b) in the lateral neck region. Debates on the extent of SNDs to be made in the central and lateral neck regions are still ongoing. Central dissection should be made at least unilaterally. In the lateral side of the neck, SNDs can be applied in different combinations in which at least one region from Groups I to V is removed. The main variables that determine the extent of SND in the central and lateral regions in DTC are the complication rates, the effect of the procedure, and its effect on prognosis and recurrence.

Current philosophy in the surgical management of neck metastases for head and neck squamous cell carcinoma

Neck dissection is an important treatment for metastases from upper aerodigestive carcinoma; an event that markedly reduces survival. Since its inception, the philosophy of the procedure has undergone significant change from one of radicalism to the current conservative approach. Furthermore, nonsurgical modalities have been introduced, and, in many situations, have supplanted neck surgery. The refinements of imaging the neck based on the concept of neck level involvement has encouraged new philosophies to evolve that seem to benefit patient outcomes particularly as this relates to diminished morbidity. The purpose of this review was to highlight the new paradigms for surgical removal of neck metastases using an evidence-based approach.

Head and neck cancer: past, present and future

Head and neck cancer consists of a diverse group of cancers that ranges from cutaneous, lip, salivary glands, sinuses, oral cavity, pharynx and larynx. Each group dictates different management. In this review, the primary focus is on head and neck squamous cell carcinoma (HNSCC) arising from the mucosal lining of the oral cavity and pharynx, excluding nasopharyngeal cancer. Presently, HNSCC is the sixth most prevalent neoplasm in the world, with approximately 900,000 cases diagnosed worldwide. Prognosis has improved little in the past 30 years. In those who have survived, pain, disfigurement and physical disability from treatment have had an enormous psychosocial impact on their lives. Management of these patients remains a challenge, especially in developing countries where this disease is most common. Of all human cancers, HNSCC is the most distressing since the head and neck is the site of the most complex functional anatomy in the human body. Its areas of responsibility include breathing, the CNS, vision, hearing, balance, olfaction, taste, swallowing, voice, endocrine and cosmesis. Cancers that occur in this area impact on these important human functions. Consequently, in treating cancers of the head and neck, the effects of the treatment on the functional outcome of the patient need the most serious consideration. In assessing the success of HNSCC treatment, consideration of both the survival and functional deficits that the patient may suffer as a consequence of their treatment are of paramount importance. For this reason, the modern-day management of head and neck patients should be carried out in a multidisciplinary head and neck clinic.

Selective neck dissection is effective in N1/N2 nodal stage oral cavity squamous cell carcinoma

PURPOSE

Although the efficacy of selective neck dissection (SND) in the management of a node-negative neck is established, its utility in the management of node-positive disease remains controversial. The objective of this study was to evaluate the oncologic safety of SND in the management of N1/N2 oral cavity squamous cell carcinoma.

MATERIALS AND METHODS

From a prospectively collected electronic database of patients with oral cavity cancer, a retrospective analysis was conducted of patients with nonrecurrent, clinical, and/or pathologic N1/N2 oral cavity squamous cell carcinoma who underwent SND of levels I to III/IV. The patients were stratified into 2 groups: clinical N0 but pathologic N1/N2 (cN0-pN1/N2) and clinical N1/N2 (cN1/N2). The primary outcome variable of the study was the ipsilateral regional recurrence rate. Categorical data were analyzed by the 2-sided Fisher exact test, and 3-year Kaplan-Meier ipsilateral regional control rate, regional recurrence-free survival, disease-free survival, and overall survival were estimated.

RESULTS

Forty-nine patients constituted the study sample, with 37 patients in the cN1/N2 group and 12 patients in the cN0-pN1/N2 group. During the follow-up period of 3 years, 2 patients (∼4%) developed ipsilateral neck recurrence, and these patients were in the cN1/N2 group. The 3-year Kaplan-Meier ipsilateral regional control rate was 95%.

CONCLUSIONS

SND may produce a satisfactory ipsilateral regional control rate in patients with early-stage node-positive oral squamous cell carcinoma. A prospective, randomized clinical trial comparing SND with modified radical neck dissection may be required for a categorical conclusion of these findings.

Anatomical variations of the spinal accessory nerve and its relevance to level IIb lymph nodes

Objective: This study was conducted to identify anatomical variations of the spinal accessory nerve (SAN) in the upper neck, the landmark of the anterior and inferior border of level IIb, and to evaluate the nerve's effect on the border and the number of lymph nodes (LNs) in level IIb.

Study Design and Setting: Case series with planned data collection.

Subjects and Methods: A total of 181 neck dissections (NDs) were prospectively enrolled in this study. The relation between the SAN and adjacent structures (internal jugular vein [IJV], sternocleidomastoid muscle [SCM], cervical plexus) and the number of LNs in level IIb was investigated.

Results: The SAN crossed the IJV ventrally in 72 cases (39.8%) and dorsally in 104 cases (57.4%), and passed through the IJV in five cases (2.8%). The SAN ran along the inner surface of the SCM and sent branches to the SCM without penetration of the muscle in 83 cases (45.9%), whereas in 98 cases (54.1%) the nerve sent branches to the SCM by penetration. Cervical plexus contribution to the SAN was seen from C2 in 96 cases (53.1%), C2 and C3 in 69 cases (38.1%), and C3 in 16 cases (8.8%). The mean number of LNs of level IIa and level IIb was 6.5 and 8.2 in cases in which the SAN crossed the IJV ventrally, and 6.8 and 5.4 in dorsally crossing cases. LNs included in the neck level IIb in ventrally crossing SAN cases were significantly larger than the dorsally crossing cases ( P < 0.05).

Conclusions: Our results may help to minimize the incidence of injuring the SAN in the upper neck during ND. Neck level IIb would contain more LNs if the course of the nerve leans toward the ventral side.

An outline of the history of head and neck oncology

This review analyzes the development of head and neck oncology as outlined in medical history articles. A systematic literature survey was conducted with the search engines "Google Scholar" and "PubMed" and the retrieved publications were cross-referenced. In addition, books and, when possible, original sources were consulted. While most of the material was obtained from publications from the modern era reviewing historical data, some of the information was derived from original source material. The obtained articles on the history of cancer were then analyzed for details on head and neck oncology. The cradle of oncology was located in ancient Egypt and Greece. The search showed that the first tumors treated in the head and neck were either cutaneous malignancies or cancers on the mucosal surfaces of the oral cavity. The origin, diagnosis and treatment of more deeply situated tumors of the larynx and hypopharynx remained obscure for many centuries. The medieval age brought little progress to medicine in general, and in head and neck oncology in particular, due to religious concerns. Renaissance medicine was characterized by advances in medicine and oncology made by systematic dissection studies of normal and pathologic anatomy. The 19th and 20th century reflect the development of head and neck oncology in the era of science based medicine. Almost all of our current understanding of head and neck oncology, our diagnostic methods and treatment strategies have been developed in these two centuries. The analysis showed that many oncologic problems, which occupy our minds today, were also concerns of our medical ancestors.

Cervical sensory preservation during neck dissection

Although the practice of neck dissection has greatly advanced from radical to function-preserving surgery, the impact of the sensory nerve-preserving neck surgery on the pain and quality of life (QOL) of patients has received little study. We evaluated neck morbidity and its impact on QOL associated with selective or modified radical neck dissection with or without preservation of cervical root branches. We conducted a retrospective cohort study comparing 24 patients who had their cervical root branches preserved to 29 patients whose root branches were removed during neck dissection. The spinal accessory nerve was preserved and sex, age, pathologic status, side and extent of neck dissection, and radiotherapy were comparable between groups. The groups were compared based on sensory and motor functions of the neck and shoulder and questionnaires on depression and QOL at follow-up of mean 18.7 (range 12-34) months after surgery. The nerve-preserved patients showed a low incidence and severity of neck and shoulder pain compared to the nerve-removed subjects (p<.05). Loss of sensation was more frequently experienced in the nerve-removed group on the earlobe and the lateral neck of the operated side (p<.05). Depression and QOL scores were higher in the nerve-removed group and significantly correlated with pain intensity. Preservation of the cervical root branches reduces postoperative pain as well as permanent anesthetic areas of the neck. This may also improve the mental state and QOL of patients undergoing neck dissection.

Neck dissection: then and now

The significance of metastatic disease in the lymph nodes of the neck as a critical independent prognostic factor in head and neck cancer has long been appreciated. Although 19th century surgeons attempted to remove involved cervical lymph nodes at the time of resection of the primary cancer, a systematic approach to en bloc removal of cervical lymph node disease, described in detail by Jawdyński in 1888 and popularized and illustrated by Crile in the early 20th century, provided consistent and more effective treatment, and forms the basis of our current techniques. During the first half of the 20th century, developments included preservation of the accessory nerve in selected cases, elective neck dissection performed in association with resection of various primary tumors, bilateral neck dissection and limited neck dissection. The greatest impetus to the status of radical neck dissection came from Martin, whose technique consisted of resection of all lymph nodes from level I-V together with the accessory nerve, internal jugular vein, sternocleidomastoid muscle and various other structures in a single block of resected tissue. Martin's technical precepts were followed until the latter part of the 20th century when modifications in technique began to find general acceptance. The first description of an effective technique of modified radical neck dissection was published in Spanish by Suárez, in 1963. This technique, which preserves important structures, such as the internal jugular vein, sternocleidomastoid muscle and accessory nerve, was refined and popularized by various authors who published their results in the English language literature during the period from 1964 through 1990 and beyond. Modified or "functional" neck dissection avoids much of the morbidity of radical neck dissection while achieving equivalent degrees of control of regional disease in properly selected cases. By the late 20th century, the concept of selective neck dissection, consisting of resection of only the nodal groups at greatest risk for metastasis from a given primary site, was studied and developed. These limited dissections are now widely employed for elective, and in properly selected cases, therapeutic treatment and staging of the neck, and have been proposed for limited cervical recurrences after various chemoradiation protocols. Prospective studies have demonstrated similar rates of neck recurrence and survival after elective selective neck dissection compared to elective modified radical neck dissection. Other modifications and factors applied to treatment of cervical lymph node disease include the use of adjuvant and neo-adjuvant radiation and chemotherapy, a revised system for classification of neck dissections, the identification of various adverse prognostic factors such as extracapsular spread and extranodal soft tissue deposits, application of sentinel lymph node biopsy to staging of the neck, the use of immunohistochemical and molecular techniques for identification of lymph node metastases not detectable by light microscopy, and the possibility of endoscopic neck dissection. The authors conclude that neck dissection, as evolved over the past century, is a fundamental tool in management of patients with head and neck cancer, but is still a work in progress.

Elective and therapeutic selective neck dissection

Selective neck dissection is a modification of the more comprehensive modified radical or radical neck dissection that is designed to remove only those nodal levels considered to be at risk for harboring nodal metastases. The role of selective neck dissection continues to evolve: while initially designed as a staging and diagnostic procedure for patients without clinical evidence of nodal disease, a growing body of literature suggests that selective neck dissection has a therapeutic role in patients with clinical and histologic evidence of nodal metastases. The rationale behind selective neck dissection, its application in the clinically negative but histologically node-positive neck and the extended application of selective neck dissection in patients with clinical evidence of nodal disease are discussed.