Endoscopic sentinel lymphadenectomy as a new diagnostic approach in the N0 neck

Esthetic neck dissection using an endoscope via retroauricular incision: a report of two cases

Various surgical techniques, such as endoscopic surgery and robotic surgery, are developed to optimize the esthetic outcome even in operations for malignancy. A modified face-lift or retroauricular approach are used to minimize postoperative scarring. Recently, robot-assisted surgery is being done in various fields and considered as favorable treatment method by many surgeons. However its high cost is a nonnegligible fraction for many patients. On the other hand, endoscopic surgery, which is cheaper than robotic surgery, is minimally invasive with contentable neck dissection. Although it is a difficult technique for a beginner surgeon due to its limited operation view, we suppose it as an alternative method for robotic surgery. Herein, we report two cases of endoscopic neck dissection via retroauricular incision with a discussion regarding the pros and cons of endoscopic neck dissection.

Current advances in diagnosis and surgical treatment of lymph node metastasis in head and neck cancer

Still today, the status of the cervical lymph nodes is the most important prognostic factor for head and neck cancer. So the individual treatment concept of the lymphatic drainage depends on the treatment of the primary tumor as well as on the presence or absence of suspect lymph nodes in the imaging diagnosis. Neck dissection may have either a therapeutic objective or a diagnostic one. The selective neck dissection is currently the method of choice for the treatment of patients with advanced head and neck cancers and clinical N0 neck. For oncologic reasons, this procedure is generally recommended with acceptable functional and aesthetic results, especially under the aspect of the mentioned staging procedure. In this review article, current aspects on pre- and posttherapeutic staging of the cervical lymph nodes are described and the indication and the necessary extent of neck dissection for head and neck cancer is discussed. Additionally the critical question is discussed if the lymph node metastasis bears an intrinsic risk of metastatic development and thus its removal in a most possible early stage plays an important role.

Minimally invasive techniques for head and neck malignancies: current indications, outcomes and future directions

The trend toward minimally invasive surgery, appropriately applied, has evolved over the past three decades to encompass all fields of surgery, including curative intent cancer surgery of the head and neck. Proper patient and tumor selection are fundamental to optimizing oncological and functional outcomes in such a personalized approach to cancer treatment. Training, experience, and appropriate technological equipment are prerequisites for any type of minimally invasive surgery. The aim of this review was to provide an overview of currently available techniques and the evidence justifying their use. Much evidence is in favor of routine use of transoral laser resection, transoral robot-assisted surgery, transnasal endoscopic resection, sentinel node biopsy, and endoscopic neck surgery for selected malignant tumors, by experienced surgical teams. Technological advances will enhance the scope of this type of surgery in the future and physicians need to be aware of the current applications and trends.

The endoscopic approach to the neck: a review of the literature, and overview of the various techniques

BACKGROUND

The endoscopic surgical approach to the neck has reached the head and neck surgeons' view with a certain delay, compared to other fields of endoscopic procedures. This may be attributed to the tight work space and plenty of vital structures in the operating field. Since study groups described first attempts with endoscopic or video assisted removals of thyroid glands in the late nineties, selective neck dissections on animal models or cadaveric dissections were performed in 2003.

METHOD

The review consists of a Medline Search regarding the terms of endoscopic, video- assisted neck dissections, excision of neck lesions, thyroidectomy and submandibular resection and minimal access surgery. The three main procedures (selective neck dissection, submandibular resection and thyroidectomy) are described and reviewed in the following test.

RESULTS

Various techniques have been performed successfully and led to good clinical results. The studies described in literature other than for thyroidectomy often do not exceed the level of small series or case-reports.

CONCLUSION

With a good proof of indication gasless lifting techniques, video assisted endoscopical techniques and subcutaneous approaches with gas filling procedures are feasible in neck surgery. All methods depending on the surgeons' experience describe no significantly extended operation times, a better and faster wound-healing and an optimized cosmetic outcome, compared to open approaches. Surgeons should always be aware of the limitations of the minimal invasive techniques regarding the complications or modifications during neck dissection/thyroidectomy.

Transoral endoscopic neck surgery: feasibility and safety in a porcine model based on the example of thymectomy

BACKGROUND

In anatomical studies and cadaver dissections, we developed an endoscopic transoral access to the anterior neck region to reduce surgical access trauma. Through a sublingual trocar and two additional trocars in the vestibule of the oral cavity, the pretracheal and thyroid region was reached with standard laparoscopic instruments.

METHODS

We conducted an experimental trial in five pigs under general anesthesia to estimate the safety and feasibility of the method; via this approach, the thymus was partially resected. Perioperative antibiotics were administered but analgesics were not given in the postoperative course. Oral intake and behavior were observed during the following 2 days. After necropsy, examination of the access route took place by means of dissections. The tissue surrounding the working trocar was histologically examined.

RESULTS

The pretracheal region could be reached without a problem and the procedure was performed almost "bloodlessly" in an anatomically defined layer. The intervention time decreased successively. Postoperative awakening was uneventful. Regular oral food intake was observed after 2-3 h. Pain reactions were not registered during the entire postoperative phase. After dissection, all relations appeared inconspicuous (no infections, fresh/old hematoma). Two local encapsulated seromas were observed. Histologically, only a mild tissue reaction was noted.

CONCLUSION

In this study, the endoscopic transoral approach to minimally invasive neck surgery seemed safe and feasible. Minimally invasive endoscopic procedures in the anterior neck region could be a possible application of this new approach.

Minimally invasive neck surgery. Surgical feasibility and physiological effects of carbon dioxide insufflation in a unilateral subplatysmal approach

Endoscopically assisted, minimally invasive techniques to regions without a natural cavity require insufflation with carbon dioxide (CO2). In the neck region this may impair hemodynamics, blood gas homoeostasis, cerebral blood circulation and increase the intracranial pressure. An exclusively endoscopic unilateral subplatysmal approach to the submandibular region was investigated in nine mini-pigs randomized to three groups. On both neck sides, within a 14 day interval, the subplatysmal space was inflated with CO2 at 10 mmHg, 20 mmHg (1.33/2.66 x 10 (3)Pa) or 20 mmHg (2.66 x 10 (3)Pa) combined with mechanical suspension. Data for hemodynamic and blood gas parameters, gas volumes, and intracranial pressure were obtained preoperatively, 30 min after onset and 10 min postopeatively. In a pocket created by insufflation of 20 mmHg (2.66 x 10 (3)Pa), exposition and resection of the submandibular gland were accomplished easily. The elevation procedure had technical disadvantages. The mean operation time was 48.9 min. Unilateral subplatysmal carbon dioxide insufflation of the submandibular neck region up to 20 mmHg (2.66 x 10 (3)Pa) did not affect physiological parameters. As an exclusive endoscopical approach for unilateral surgery of the submandibular region, the use of inflation pressures of up to 20 mmHg (2.66 x 10 (3)Pa) might be considered.

Sentinel node concept in clinically n0 laryngeal and hypopharyngeal cancer

BACKGROUND

Sentinel nodes (SNs) are the lymph nodes that directly receive lymphatic flow from a primary cancer lesion. The SN concept implies that lymphatic metastasis initially occurs at SNs. SN navigation surgery can be introduced for cancers in which the SN concept is established. In SN navigation surgery, lymph node dissection beyond SNs can be omitted if SNs are metastasis free. Although the SN concept has been investigated frequently for oral and oropharyngeal cancer, it has so far been investigated less for laryngeal and hypopharyngeal cancer. In this study, we investigated whether the SN concept is applicable for laryngeal and hypopharyngeal cancer.

METHODS

Twenty patients with T2-T4 and clinically N0 laryngeal and hypopharyngeal cancer were recruited. (99m)Tc-phytate was injected into several sites surrounding the tumor on the day before surgery. Lymphoscintigrams were acquired from at least two different viewpoints. SNs were surveyed intraoperatively, and neck dissections including at least levels II, III, and IV were performed.

RESULTS

SNs had occult metastases in five cases. In the remaining 15 cases, neither SNs nor other lymph nodes contained metastases, consistent with the SN concept. There was one false-negative case showing delayed nodal metastasis 2 years after initial surgery. The overall accuracy of the SN concept was 95%.

CONCLUSION

Our study shows that SN biopsy is a reliable strategy to determine correct lymph node status in N0 laryngeal and hypopharyngeal cancer. SN detection was valuable in evaluating the need for neck dissection, whether ipsilaterally or bilaterally.

Clinical patterns of metastasis

In human solid cancer, lymph node status is the most important indicator for clinical outcome. Recent developments in the sentinel lymph node concept and technology have resulted in a more precise way of examining micrometastasis in the sentinel lymph node and the role of lymphovascular system in the facilitation of cancer metastasis. Different patterns of metastasis are described with respect to different types of solid cancer. Expect perhaps for papillary carcinoma and sarcoma, the overwhelming evidence is that solid cancer progresses in an orderly progression from the primary site to the regional lymph node or the sentinel lymph node in the majority of cases with subsequent dissemination to the systemic sites. The basic mechanisms of cancer metastasis through the lymphovascular system form the basis of rational therapy against cancer. Beyond the clinical patterns of metastasis, it is imperative to understand the biology of metastasis and to characterize patterns of metastasis perhaps due to heterogeneous clones based on their molecular signatures.

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.

Endoscopic Sentinel Lymph Node Biopsy in a Porcine Model

OBJECTIVE

The objective of this study was to investigate the feasibility of endoscopic sentinel lymph node biopsy in a porcine model.

METHODS

One hundred microcuries of technetium-labeled sulfa colloid (Tc-SC) was injected into the right and left ventrolateral surfaces of the oral tongue of six adult Yorkshire pigs. A handheld gamma probe was used to locate the region of focal radioactivity on the neck that corresponded to the sentinel lymph node (SLN). Next, 0.25 mL of isosulfan blue dye was injected into the Tc-SC injection sites on the tongue. Endoscopic SLN dissection was then performed using a combination of balloon dissection and CO2 insufflation. The operative time, blood loss, and radioactivity of the SLN were measured for each animal.

RESULTS

The SLN was detected transcutaneously with the gamma probe, and endoscopic SLN excision was successful. Endoscopic visualization and an endoscopic gamma probe confirmed the presence of both isosulfan blue dye and radiopositivity in the SLN in each pig. The procedure lasted 22 to 61 minutes (median duration, 35 minutes). There was no measurable blood loss in any of the animals. Mean radioactivity measured 14,466 counts/second per lymph node.

CONCLUSIONS

Endoscopic SLN biopsy for oral tongue lesions is feasible and warrants further study.

Sentinel-Lymphknoten bei oralen und oropharyngealen epithelialen Tumoren

Carcinomatous metastases in regional lymph nodes worsen substantially the prognosis of patients with oral cavity and oropharyngeal cancer. Due to the high probability of occult metastasis (about 30%), during surgical resection of the primary tumor usually also elective dissection of lymph nodes is performed. Opinions on the extent of the elective neck dissection still differ, whereas selective dissection increasingly gains in importance. The aim of selective dissections, based on the predictability of formation of metastases, is the identification and exstirpation of the sentinel lymph node. In this prospective study the applicability of the concept of the sentinel lymph node in patients with oral cavity and oropharyngeal cancer was analysed. 12 patients with oral cavity and orophangeal cancer, staging T1-T3, all N0 (examined by palpation and sonography) were included. The localization of the sentinel(s) was determined preoperatively by radioisotope (Tc Nanocolloid). Sentinel(s) were identified first with a gamma probe (Neoprobe 2000); we then injected methylene blue into the peritumoral area for easier detection of the sentinel(s). The sentinels were removed and sent for frozen section examination. Regardless of the findings of the frozen section examination modified dissection was carried out. Later we compared frozen sections with paraffin microtome sections of sentinel(s) and of other exstirpated neck lymph nodes. We could identify the sentinel lymph node in all patients, in 6/12 patients we found several sentinels. If sentinels were not affected by tumor cells, there were no metastases in the downstream neck lymph nodes either. If in the sentinel lymph nodes no metastases can be determined, eliminating the environment alone could be sufficient. However, this assumption requires verification in a larger patient group.

Role of sentinel node biopsy in the management and staging of the N0 neck

Sentinel node biopsy is being increasingly used as a staging tool for mucosal head and neck cancer. This review of the literature summarizes the results of research into the procedure when it has been performed in three main contexts: as part of an ipsilateral neck dissection, as a stand-alone procedure to stage the neck for positive or negative disease, and as a means of investigating the non-involved or contralateral neck in tumors close to or crossing the midline. The role of the procedure is discussed and the difficulties encountered are expanded, with a particular emphasis on pitfalls of the technique, caveats, and its potential role for the future.