The underappreciated role of auriculotemporal nerve involvement in local failure following parotidectomy for cancer.

BACKGROUND: Locoregional recurrence rates following parotidectomy for cancer remain as high as 20-30%. The auriculotemporal nerve (ATN) may allow parotid cancers to spread from the facial nerve (FN) toward the skull base, causing local recurrence. METHODS: Retrospective review of 173 parotidectomies for malignancy. Preoperative and post-recurrence imaging were reviewed by a neuroradiologist for signs of tumor adjacent to the ATN. RESULTS: Clinical and imaging signs of possible ATN involvement correlated with FN weakness and sacrifice. Eight patients had pathologically confirmed tumor from the ATN or V3. Forty-four percent of local recurrences had post-recurrence imaging showing tumor along the course of the ATN. Locoregional failure along the ATN was also associated with preoperative FN weakness, intraoperative FN sacrifice, and failure to complete recommended adjuvant therapy. CONCLUSIONS: Parotid cancers may invade the FN and spread to the skull base via the ATN. If not appropriately managed, this may lead to local recurrence.

AJCC-8ed nodal staging does not predict outcomes in surgically managed HPV-associated oropharyngeal cancer.

OBJECTIVE: To assess the pathological outcomes of surgically-managed human papillomavirus (HPV) positive oropharyngeal squamous cell carcinoma (OPSCC) using the 8th Edition of the American Joint Committee on Cancer Staging Manual (AJCC-8ed). MATERIALS AND METHODS: A retrospective review was conducted of 156 patients with previously untreated OPSCC who underwent primary TORS between March 2010 and February 2015 to evaluate the impact of the new AJCC-8ed pathologic staging system. Only patients who had complete pathologic staging with neck dissection and at least 2 years of follow-up records or disease recurrence within 2 years were included for analysis. RESULTS AND CONCLUSIONS: Of the 156 patients, 116 patients had neck dissections and adequate follow-up data. There were 10 total recurrences, including 2 regional recurrences and 1 local recurrence. Lymph node size, number of positive lymph nodes, and presence of any positive nodes were not associated with recurrence for HPV-positive patients. The presence of extranodal extension approached significance. Pathologic N-stage was not predictive of recurrence under the AJCC-7ed or the AJCC-8ed systems. Cancer staging under the AJCC-8ed, but not the AJCC-7ed system was significantly associated with recurrence. In conclusion, pathologic node status as defined in the AJCC-8ed pathologic staging system does not appear to drive prognosis for surgically managed patients. While the new AJCC-8ed staging is an improvement in prognostication, the use of T-stage alone is still a better predictor of recurrence. TORS with adjuvant therapy determined by pathologic findings provides excellent locoregional control for HPV-positive OPSCC.

Phase I Trial Using Induction Ciplatin, Docetaxel, 5-FU and Erlotinib Followed by Cisplatin, Bevacizumab and Erlotinib With Concurrent Radiotherapy for Advanced Head and Neck Cancer.

OBJECTIVES: Bevacizumab (avastin) and erlotinib (tarceva) had shown early clinical activity against head and neck cancer (HNC). We initiated a phase I trial of induction cisplatin, docetaxel, 5-fluorouracil and erlotinib (TPF-E) followed by cisplatin, bevacizumab and erlotinib (PA-E) with radiotherapy (XRT) for advanced HNC. The goal was to determine maximum tolerated erlotinib dose. METHODS: Eligible patients had stage IVA or higher HNC with good performance status, hematologic, and renal reserve. Two cycles of induction TPF-E were administered. XRT was administered with concurrent weekly cisplatin and bevacizumab every 2 weeks. Initial erlotinib dose was 50 mg daily from start of induction chemotherapy until radiotherapy completion. Erlotinib dose escalations to 100 and 150 mg were planned. RESULTS: Thirteen patients with previously untreated locoregional disease (11 patients) or oligometastatic (2 patients) HNC were enrolled. Totally, 11 of 13 patients completed XRT as planned. Four of 8 patients in cohort 1 (erlotinib 50 mg), 3 of 4 patients in cohort 2 (100 mg), and 0 of 1 patients in cohort 3 (150 mg) completed the regimen. Two patients had significant gastrointestinal complications (bleeding and perforation), and 1 had dose-limiting diarrhea. Maximum tolerated dose was reached at 50 mg erlotinib. At median 23.4 months follow-up, 5 patients (38%) have no evidence of disease, and 2 (15%) have stable but measurable disease. CONCLUSIONS: Erlotinib in combination with induction TPF followed by erlotinib, cisplatin, and bevacizumab with XRT is active but toxic. Gastrointestinal toxicities partly caused high rates of study withdrawal. All doses studied in this protocol caused unexpected toxicities and we do not recommend advancement to phase II.

Safety and efficacy of functional laryngectomy for end-stage dysphagia.

OBJECTIVES/HYPOTHESIS: To evaluate functional outcomes and complication rate after total laryngectomy (TL) for dysfunctional larynx with end-stage dysphagia. STUDY DESIGN: Retrospective chart review. METHODS: Chart review was performed on all patients who underwent TL from January 2008 to July 2016 at a single tertiary academic medical center. Patients who underwent TL for dysfunctional larynx without preoperative evidence of malignancy were included. Main outcome measures were post-TL functional swallowing and speech outcomes, and complication rate. RESULTS: The study included 19 patients from a cohort of 278 consecutive patients. All patients were previously treated with radiotherapy (RT), whereas 13/19 (68%) previously received chemoradiotherapy. The median time from RT to TL was 10.98 years (range, 0.67-23.94 years). Aspiration was evident preoperatively in 17/19 (89%) patients, with 11 experiencing recurrent aspiration pneumonia. Seventeen of 19 (89%) patients were nil per os (NPO) requiring enteral nutrition. Six of 19 (32%) patients had surgical complications, including three (16%) pharyngocutaneous fistulas. At 3-month and 1-year postoperative follow-up, there was significant improvement in mean Functional Oral Intake Scale (FOIS) score and aspiration, recurrent pneumonia, enteral nutrition, and NPO status rates (P < .05). At 1-year follow-up, no patients were NPO, and only one patient required gastrostomy tube supplementation. Mean FOIS score increased from 1.3 to 6.1 (P = .001). Eight of 13 patients (62%) were actively using a tracheoesophageal prosthesis at 1-year follow-up. CONCLUSIONS: Laryngectomy for dysfunctional larynx eliminates the morbidity of aspiration while improving diet and reducing gastrostomy tube dependence with an acceptable complication rate. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:597-602, 2018.

Multicompartment metabolism in papillary thyroid cancer.

OBJECTIVES/HYPOTHESIS: In many cancers, varying regions within the tumor are often phenotypically heterogeneous, including their metabolic phenotype. Further, tumor regions can be metabolically compartmentalized, with metabolites transferred between compartments. When present, this metabolic coupling can promote aggressive behavior. Tumor metabolism in papillary thyroid cancer (PTC) is poorly characterized. STUDY DESIGN: Immunohistochemical staining of tissue samples. METHODS: Papillary thyroid cancer specimens from 46 patients with (n = 19) and without advanced disease (n = 27) were compared to noncancerous thyroid tissue (NCT) and benign thyroid specimens (n = 6 follicular adenoma [FA] and n = 5 nodular goiter [NG]). Advanced disease was defined as the presence of lateral neck lymphadenopathy. Immunohistochemistry was performed for translocase of outer mitochondrial membrane 20 (TOMM20), a marker of oxidative phosphorylation, and monocarboxylate transporter 4 (MCT4), a marker of glycolysis. RESULTS: Papillary thyroid cancer and FA thyrocytes had high staining for TOMM20 compared to NCT and nodular goiter (NG) (P < 0.01). High MCT4 staining in fibroblasts was more common in PTC with advanced disease than in any other tissue type studied (P < 0.01). High MCT4 staining was found in all 19 cases of PTC with advanced disease, in 11 of 19 samples with low-stage disease, in one of five samples of FA, in one of 34 NCT, and in 0 of six NG samples. Low fibroblast MCT4 staining in PTC correlated with the absence of clinical adenopathy (P = 0.028); the absence of extrathyroidal extension (P = 0.004); low American Thyroid Association risk (P = 0.001); low AGES (age, grade, extent, size) score (P = 0.004); and low age, metastasis, extent of disease, size risk (P = 0.002). CONCLUSION: This study suggests that multiple metabolic compartments exist in PTC, and low fibroblast MCT4 may be a biomarker of indolent disease. LEVEL OF EVIDENCE: N/A. Laryngoscope, 126:2410-2418, 2016.

Prognostic Indications of Elevated MCT4 and CD147 across Cancer Types: A Meta-Analysis.

BACKGROUND: Metabolism in the tumor microenvironment can play a critical role in tumorigenesis and tumor aggression. Metabolic coupling may occur between tumor compartments; this phenomenon can be prognostically significant and may be conserved across tumor types. Monocarboxylate transporters (MCTs) play an integral role in cellular metabolism via lactate transport and have been implicated in metabolic synergy in tumors. The transporters MCT1 and MCT4 are regulated via expression of their chaperone, CD147. METHODS: We conducted a meta-analysis of existing publications on the relationship between MCT1, MCT4, and CD147 expression and overall survival and disease-free survival in cancer, using hazard ratios derived via multivariate Cox regression analyses. RESULTS: Increased MCT4 expressions in the tumor microenvironment, cancer cells, or stromal cells were all associated with decreased overall survival and decreased disease-free survival (p < 0.001 for all analyses). Increased CD147 expression in cancer cells was associated with decreased overall survival and disease-free survival (p < 0.0001 for both analyses). Few studies were available on MCT1 expression; MCT1 expression was not clearly associated with overall or disease-free survival. CONCLUSION: MCT4 and CD147 expression correlate with worse prognosis across many cancer types. These results warrant further investigation of these associations.

Value of fluoro-2-deoxy-D-glucose-positron emission tomography for detecting metastatic lesions in head and neck cancer.

OBJECTIVES: The role of positron emission tomography (PET) scans in the staging of head and neck cancer (HNC) is unclear. The National Comprehensive Cancer Network guidelines do not recommend routine metastatic workup beyond physical examination, chest x-ray, and laboratory tests. The purpose of this report is to examine the accuracy of staging PET scans for detecting distant metastatic disease in patients with HNC. METHODS: Retrospective review of 182 consecutive newly diagnosed HNC patients who had a staging PET scan at Thomas Jefferson University Hospital between 2003 and 2007. RESULTS: The overall incidence of confirmed distant metastatic disease in this population was 5.0%. About 26 of the staging PET scans had areas suspicious for a metastatic lesion(s). Of total, 23 patients were further evaluated with imaging and/or biopsy, revealing 9 (39%) true positives, and 14 (60%) false positives. Of the 156 negative PET scans, there was 1 false negative and 155 true negatives. Thus, the sensitivity of PET was 90% and specificity was 92%. Positive predictive value was 39% and negative predictive value was 99.4%. No patients with pre-PET clinical stage I or II cancer had confirmed distant metastases. The only statistically significant predictor for metastatic disease was clinical stage IV versus all other stages (P=0.03). CONCLUSIONS: Given the marked differences in the treatment of locally advanced/nonmetastatic HNC versus metastatic HNC, we recommend PET for clinical stage IV disease. Although the sensitivity, specificity, and negative predictive value rates were acceptable, the positive predictive value was suboptimal. Patients found to have a PET scan "positive" for metastatic disease require confirmatory imaging or ideally biopsy.

Localized oropharyngeal amyloidosis.

An otherwise healthy 29-year-old woman presented with a complaint of odynophagia of several months' duration. On examination, she was found to have a broadly based, yellow, exophytic lesion on the right lateral pharyngeal wall. Findings on biopsy were consistent with amyloidosis. The patient underwent tonsillectomy with resection of the oropharyngeal lesion. Final pathology established a diagnosis of nodular non-AL-type amyloidosis. Localized amyloidosis of the oropharynx is exceptionally rare. Additionally, most cases of localized amyloidosis are of the AL type, not the AA (i.e., non-AL) type seen in this patient.

Prevalence of complementary and alternative medicine use among a population of head and neck cancer patients: a survey-based study.

We sought to determine the prevalence and patterns of complementary and alternative medicine (CAM) use among head and neck cancer patients who were being treated at an academic otolaryngology practice in the northeastern United States from January 2005 through December 2006. During a 3-month period, we conducted an anonymous survey of 213 new and established patients regarding their use of CAM during their cancer treatment. According to the responses, only 13 of these patients (6.1%) were currently using CAM during treatment. With respect to the various products being taken, 9 patients (69.2% of all CAM users) were taking herbs or supplements. Only 7 patients (53.8%) who used CAM disclosed this fact to their physician during in-office encounters. The most common sources for obtaining CAM were health-food stores, where most patients spent approximately $25 per week. The most frequently cited reason for using CAM was that a particular product had been recommended by family or friends as being potentially helpful. No adverse effects of CAM were reported. We conclude that while CAM use was not very prevalent in this study, patients who did use it were employing modalities with biologic activity that may potentially interact with conventional therapies. Because patients' disclosure of CAM use is frequently not volunteered, otolaryngologists should routinely elicit this information in a highly specific fashion so that we may better serve our unique patient population.

Correlation of positron emission tomography with fine needle aspiration biopsies in head and neck malignancy.

OBJECTIVE: To investigate whether a correlation between fine needle aspiration cytology and positron emission tomography (PET) exists in the preoperative screening, staging and diagnosis of head and neck cancer. STUDY DESIGN: We retrospectively correlated fine needle aspiration biopsy (FNAB) and PET scan in patients with head and neck lesions. RESULTS: There were 92 FNABs with corresponding PET scan in 83 patients. Mean standard uptake value (SUV) for benign lymph nodes was 5.05 (SD, 5.79), and 13.56 (SD, 6.38) and 16.99 (SD, 19.04) for squamous carcinoma and other malignancies, respectively. Ideal SUV cutoff value was determined to be 6.0. Of 66 malignant FNABs, 52 had an SUV > or = 6, 8 had an SUV < 6, and 6 were interpreted as "hypermetabolic." Of 26 benign FNAB (SUV was available for 17), 8 were interpreted as "hypermetabolic" and 1 as "not hypermetabolic." Of those with SUVs reported, 15 were < 6 while 2 were > or = 6. CONCLUSION: Lesions with SUV 6 are more likely to harbor malignancy, while lesions with repeatedly negative FNAB in the context of SUV > 6 should be considered for open biopsy. Further, lesions with SUV < 6 may harbor malignancy and therefore fine needle aspiration biopsy is also recommended.

Daily image guidance with cone-beam computed tomography for head-and-neck cancer intensity-modulated radiotherapy: a prospective study.

PURPOSE: To report on a prospective clinical trial of the use of daily kilovoltage cone-beam computed tomography (CBCT) to evaluate the interfraction and residual error motion of patients undergoing intensity-modulated radiotherapy for head-and-neck cancer. METHODS AND MATERIALS: Patients were treated with intensity-modulated radiotherapy with an Elekta linear accelerator using a mounted CBCT scanner. CBCT was performed before every treatment, and translational (but not rotational) corrections were performed. At least once per week, a CBCT scan was obtained after intensity-modulated radiotherapy. Variations were measured in the medial-lateral, superoinferior, and anteroposterior dimensions, as well as in the rotation around these axes. RESULTS: A total of 28 consecutive patients (1,013 CBCT scans) were studied. The average interfraction shift was 1.4 +/- 1.4, 1.7 +/- 1.9, and 1.8 +/- 2.1 mm in the medial-lateral, superoinferior, and anteroposterior dimensions, respectively. The corresponding average residual error shifts were 0.7 +/- 0.8, 0.9 +/- 0.9, and 0.9 +/- 0.9 mm. These data indicate that in the absence of daily CBCT image-guided radiotherapy, a clinical target volume to planning target volume margin of 3.9, 4.1, and 4.9 mm is needed in the medial-lateral, superoinferior, and anteroposterior dimensions, respectively. With daily CBCT, corresponding margins of 1.6, 2.5, and 1.9 mm should be acceptable. Subgroup analyses showed that larynx cancers and/or intratreatment weight loss indicate a need for slightly larger clinical target volume to planning target volume margins. CONCLUSION: The results of our study have shown that image-guided radiotherapy using CBCT for head-and-neck cancer is effective. These data suggest it allows a reduction in the clinical target volume to planning target volume margins by about 50%, which could facilitate future studies of dose escalation and/or improved toxicity reduction. Caution is particularly warranted for cases in which the targets are mobile (e.g., the tongue).

Management of the neck in differentiated thyroid cancer.

Differentiated thyroid cancer is characterized by an excellent long-term prognosis, which unlike other head and neck carcinomas, is not influenced definitively by regional lymph node metastasis. The relative rarity of the disease, together with its tendency for delayed metastasis and its low mortality, makes a prospective randomized trial comparing treatment outcomes difficult. As a result, the effect of cervical lymph node metastases on survival is unclear, making meaningful recommendations for their management somewhat subjective. This article discusses guidelines for the management of the neck in differentiated.

Superficial musculoaponeurotic system elevation and fat graft reconstruction after superficial parotidectomy.

OBJECTIVE/HYPOTHESIS: Elevation of the superficial musculoaponeurotic system (SMAS) with or without fat graft interposition during superficial parotidectomy prevents a concave facial deformity and Frey's syndrome. STUDY DESIGN: Retrospective, case-control study. METHODS: Charts for 248 patients who underwent superficial parotidectomy were reviewed for pathologic, radiographic, clinical, and operative data. Sixteen patients who underwent SMAS elevation and 34 patients who underwent SMAS elevation with fat graft interposition were included in two study groups. Nonreconstructed controls were randomly selected from a pool of patients who had unilateral, superficial parotidectomy and were matched based on pathologic specimen volume. Patients were surveyed for their postoperative symptoms. RESULTS: Patients undergoing SMAS elevation alone (n = 16) compared with controls (n = 19) had greater facial symmetry (12% vs. 32%, P = .147) and a lower incidence of symptomatic Frey's syndrome (6.3% vs. 18.6%, P = .382). Patients undergoing SMAS elevation and fat graft interposition (n = 34) compared with controls (n = 38) had less facial asymmetry (9% vs. 39%, P = .002) and a lower incidence of symptomatic Frey's syndrome (6% vs. 28%, P = .04). Complications among the study and control groups were comparable. CONCLUSIONS: Simultaneous reconstruction of a superficial parotidectomy defect using SMAS elevation with or without fat grafting may improve postoperative facial symmetry and decrease the incidence of symptomatic Frey's syndrome without increasing complications.

Ultrasound-guided contrast-enhanced sentinel node biopsy of the head and neck in a porcine model.

OBJECTIVE: To test the feasibility of contrast-enhanced ultrasound (CEUS)-guided sentinel lymph node biopsy (SNB) of the head and neck in a porcine model. STUDY DESIGN AND SETTING: In this prospective, nonrandomized study, methylene blue and Sonazoid were injected into the lateral tongue or floor of mouth (FOM) of four swine. Real-time CEUS was used to identify contrast in the lymphatic channels flowing to the sentinel lymph node (SLN). Endoscopic or open SNB was performed. Neck dissection was then performed, and the residual nodal packet was examined for remaining contrast-enhancing or blue dye-stained nodes. RESULTS: In all eight procedures, the SLN was visualized with ultrasound and blue dye. Seven procedures identified a single SLN, and one identified two SLNs. Subsequent neck dissections revealed no other nodes containing methylene blue or contrast in the nodal specimen or operative bed. CONCLUSION/SIGNIFICANCE: CEUS-guided SNB of the head and neck in swine is feasible, with success comparable to blue dye-guided SNB. This technique may offer several advantages over traditional techniques, and warrants further study.

Intraoperative pathologic examination: cost effectiveness and clinical value in patients with cytologic diagnosis of cellular follicular thyroid lesion.

OBJECTIVE: Routine use of intraoperative pathologic examination (IOPE), including frozen section (FS) and scrape preparation cytology (SPC), during diagnostic thyroid lobectomy continues to be a source of controversy. We sought to better delineate the usefulness and cost-benefit ratio of IOPE in the context of cytologically diagnosed cellular follicular lesion (CFL) or follicular neoplasm (FN). DESIGN: Records of 205 patients who underwent thyroidectomy for cytologically diagnosed FN or CFL between 1997 and 2005 were retrospectively reviewed. IOPE results, patient demographics, and tumor characteristics were correlated to final histopathologic diagnoses. Sensitivity, specificity, predictive values, accuracy, and costs of IOPE were calculated. MAIN OUTCOME: IOPE correctly identified 3 of 16 follicular carcinomas and 9 of 36 papillary carcinomas. Sensitivity, specificity, and accuracy were 23%, 99%, and 78%, respectively. On univariate analysis, malignancy risk among follicular nodules did not correlate with age, gender, or nodule size. On multivariate analysis, nodule size was predictive of malignancy (p < 0.05). Over the entire patient series, routine IOPE resulted in a net cost savings of $74,304.33. CONCLUSIONS: IOPE reduced costs and limited the number of completion thyroidectomies necessary. IOPE is specific, cost effective, and of minimal additional risk when performed routinely for patients with CFL or FN.

Feasibility of endoscopic sentinel node biopsy in the porcine neck.

OBJECTIVE: To assess the feasibility of endoscopic sentinel node biopsy (SNB) using a tracer dye in a pig model. STUDY DESIGN AND SETTING: This was a prospective, nonrandomized experimental study in Yorkshire pigs. The posterolateral tongues of three animals were injected with a one-to-one solution of carbon dye to methylene blue dye. Endoscopic SNB was performed and stained lymph nodes identified and retrieved, followed by an open dissection to recover any remaining nodes. Specimens were analyzed by a pathologist for staining, size, and structural integrity. RESULTS: Six unilateral endoscopic SNBs were performed without complications. During endoscopic dissection, gross blue-staining of a sentinel node was noted in four of six dissections (66%). One of six sentinel nodes demonstrated histologic evidence of carbon staining. Structural integrity of all nodes was intact upon histological evaluation. CONCLUSION/SIGNIFICANCE: Endoscopic cervical SNB in pigs is feasible but has limitations based on lymph node size and reliability of tracer dyes. Further study is warranted to perfect tracer dyes and retrieval methods to improve this technique.

A review of the endoscopic approach to the pituitary through the sphenoid sinus.

PURPOSE OF REVIEW: The refinement of minimally invasive endoscopic techniques has resulted in 'pure' endoscopic endonasal trans-sphenoidal surgery, which is a new approach for the removal of pituitary tumors. RECENT DEVELOPMENTS: This procedure is performed via a wide anterior sphenoidotomy with detachment of the septum from the sphenoid face, and avoids the use of a trans-sphenoidal retractor and any intraoral or nasal incisions. Straight and angled endoscopes are used throughout the procedure to provide a wide view of the sella and are manipulated by a co-surgeon. This technique represents an improvement over pituitary microsurgery, with decreased post-operative morbidities and a shortened postoperative stay, and it eliminates the need for packing while providing an opportunity to monitor the sella after surgery. The technique has been established as being efficacious and safe. It incorporates image-guided surgery, with the fusion of computer tomography and magnetic resonance imaging, and employs new and dedicated instrumentation. Training in endoscopic techniques is required. SUMMARY: Future advancements in intraoperative imaging, cranial base reconstruction, and robotics will make this technique even more successful.

Combined laryngotracheal separation and esophageal injury following blunt neck trauma.

In this article we describe the first case of combined laryngotracheal and esophageal injury following blunt neck trauma in the otolaryngology literature and delineate appropriate management considerations. Successful reconstruction requires appropriate airway management, restoration of esophageal and laryngeal mucosal integrity, and reduction of tracheal and laryngeal fractures with appropriate stenting. Laryngotracheal separation following blunt neck trauma is rare and can be initially overlooked. After the airway is secure, injury severity dictates repair and postoperative care. Immediate reconstruction with restoration of the laryngotracheal framework and mucosal integrity enables patients to recover a patent airway, functional voice, and normal swallow.

Recurrent polymorphous low-grade adenocarcinoma manifesting as a sinonasal mass: a case report.

Polymorphous low-grade adenocarcinoma (PLGA) is a malignant neoplasm that tends to follow a benign clinical course. Recurrences are uncommon. We report a case of recurrent PLGA of the paranasal sinuses that manifested as a large mass that filled the entire nasal cavity and left maxillary sinus. To our knowledge, this is the first reported case of a recurrent PLGA of the paranasal sinuses.

Nerve monitoring and stimulation during endoscopic neck surgery in the pig.

OBJECTIVES: To determine the feasibility of recurrent laryngeal nerve monitoring and stimulation during endoscopic neck surgery in an animal model. STUDY DESIGN: Prospective, nonrandomized experimental investigation in a porcine model. METHODS: Bilateral recurrent laryngeal nerve monitoring and stimulation was accomplished during endoscopic neck surgery in five domestic pigs. Each pig was intubated with an electromyography endotracheal tube. Recurrent laryngeal nerve function was monitored throughout the endoscopic neck surgery with a nerve integrity monitor system. An endoscopic surgical pocket was created in the neck using blunt dissection followed by low-pressure carbon dioxide insufflation. Under direct endoscopic visualization, the trachea, thyroid gland, and associated vasculature were identified. The recurrent laryngeal nerve was identified on each side of the animal and was successfully stimulated with a monopolar stimulator probe. RESULTS: Ten of ten recurrent laryngeal nerves were successfully monitored and stimulated. No significant complications were encountered during the procedures. CONCLUSIONS: Recurrent laryngeal nerve monitoring and stimulation may be successfully accomplished during endoscopic neck surgery.