Transoral Robotic Surgery with Sialendoscopy for a Plunging Ranula.

BACKGROUND/AIMS: Plunging ranulas are oral mucoceles that often cannot be visualized directly and thus can be challenging to diagnose and differentiate from other neck lesions. Surgery is the preferred treatment option, but the optimal approach requires careful consideration. METHODS: We report the case of a plunging ranula presenting as an isolated neck mass in a 33-year-old patient. This patient was treated with a novel transoral robotic surgery (TORS)-assisted approach aided by sialendoscopy. RESULTS: TORS allowed for exceptional visualization and access to the plunging ranula and sublingual gland while avoiding critical neurovascular structures. The patient healed well without recurrence or complications. CONCLUSION: The TORS approach with sialendoscopy for plunging ranulas described in this case report shows promise and should be considered for certain clinical presentations. Additional studies evaluating the effectiveness of TORS for plunging ranulas may be indicated.

Superior laryngeal nerve monitoring using laryngeal surface electrodes and intraoperative neurophysiological monitoring during thyroidectomy.

The objective of this study is to establish normative waveform data for the external branch of the superior laryngeal nerve (SLN) utilizing laryngeal surface electrodes and intraoperative neurophysiological monitoring (IONM) in conjunction with a clinical neurophysiologist. A retrospective chart review of 91 consecutive at-risk SLN were identified in 51 patients in whom IONM using laryngeal surface electrodes was performed by a clinical neurophysiologist using Dragonfly (Neurovision Medical Products, Ventura, CA) recording electrodes and a Protektor (Natus Medical Inc., San Carlos, CA)16 channel- intraoperative nerve monitoring system. Inclusion criteria were met for 30 SLN. Data collected included preoperative diagnosis, surgical procedure, rates of nerve identification and stimulation, and waveform characteristics. Waveform analysis for 30 SLN yielded a peak latency of 4.0 ± 0.2 ms, onset latency 2.3 ± 0.1 ms, peak-to-peak amplitude of 220.4 ± 31.1 µV, onset-to-peak amplitude of 186.0 ± 25.0 µV, and stimulation current threshold of 0.55 ± 0.03 mA (data = mean ± SEM). Two patients had abnormal SLN function documented clinically on postoperative laryngoscopic examination. Laryngeal surface electrodes were successfully utilized to identify and monitor SLN function intraoperatively. IONM using laryngeal surface electrodes enables analysis of waveform morphology and latency in addition to threshold and amplitude data obtained with the traditional NIM system, potentially improving the performance of nerve monitoring during thyroid surgery.

Alpha-adrenoceptor-mediated vasoconstriction is not involved in impaired functional vasodilation in the obese Zucker rat.

1. Obesity/metabolic syndrome is associated with augmented a-adrenoceptor sensitivity and impaired hyperaemic responses to exercise. Thus, it is possible that this elevated a-adrenoceptor constriction contributes to the blunted hyperaemic response. 2. Male lean and obese Zucker rats were instrumented for acute measurements of blood pressure (BP) and iliac blood flow (BF). Changes in BP and BF were determined in anaesthetized animals in response to intravenous administration of increasing doses of the a(1)-adrenoceptor agonist phenylephrine (PE). Once BF and BP returned to normal, a single bolus of the a-adrenoceptor antagonist phentolamine (0.5 mg) was administered. In separate animals, the spinotrapezius muscle was exteriorized for direct in situ observation of the microcirculation in response to phentolamine and muscle contraction. 3. Administration of PE demonstrated that iliac BF is highly autoregulated in the face of increasing perfusion pressure. Iliac conductance following phentolamine was significantly greater in obese rats. Following phentolamine administration, iliac vascular conductance was significantly greater in obese rats compared with lean animals. However, a-adrenoceptor blockade did not significantly alter arteriolar diameter in the spinotrapezius muscle during muscle contraction in either lean or obese animals. 4. These results suggest a greater contribution of the a-adrenoceptors in basal hindlimb vascular tone in obese rats. Furthermore, an augmented a-adrenoceptor-mediated vasoconstriction may not contribute to the impaired functional dilation in anaesthetized obese rats.

Quantitative Circulatory Physiology: an integrative mathematical model of human physiology for medical education.

We have developed Quantitative Circulatory Physiology (QCP), a mathematical model of integrative human physiology containing over 4,000 variables of biological interactions. This model provides a teaching environment that mimics clinical problems encountered in the practice of medicine. The model structure is based on documented physiological responses within peer-reviewed literature and serves as a dynamic compendium of physiological knowledge. The model is solved using a desktop, Windows-based program, allowing students to calculate time-dependent solutions and interactively alter over 750 parameters that modify physiological function. The model can be used to understand proposed mechanisms of physiological function and the interactions among physiological variables that may not be otherwise intuitively evident. In addition to open-ended or unstructured simulations, we have developed 30 physiological simulations, including heart failure, anemia, diabetes, and hemorrhage. Additional stimulations include 29 patients in which students are challenged to diagnose the pathophysiology based on their understanding of integrative physiology. In summary, QCP allows students to examine, integrate, and understand a host of physiological factors without causing harm to patients. This model is available as a free download for Windows computers at http://physiology.umc.edu/themodelingworkshop.

Transoral Robotic Surgery-Assisted Endoscopy With Primary Site Detection and Treatment in Occult Mucosal Primaries.

Importance: Management of cervical lymph node metastasis without a known primary tumor is a diagnostic and treatment challenge for head and neck oncologists. Identification of the occult mucosal primary tumor minimizes the morbidity of treatment. Objective: To analyze the role of transoral robotic surgery (TORS) in facilitating the identification of a primary tumor site for patients presenting with squamous cell carcinoma of unknown primary (CUP). In addition, we assessed treatment deintensification by determining the number of patients who did not undergo definitive radiation therapy and chemotherapy. Design, Setting, and Participants: In this retrospective case series from January 2011 to September 2015, 60 consecutive patients with squamous cell CUP who underwent TORS-assisted endoscopy and ipsilateral neck dissection were included from an academic medical center and studied to study the rate success rate of TORS identifying occult mucosal malignancy. Main Outcomes and Measures: Success rate of identifying occult mucosal malignancy; usage of radiation therapy and chemotherapy. Results: Overall, 60 patients (mean [SD] age, 55.5 [8.9] years) were identified; 48 of the 60 patients (80.0%) had a mucosal primary identified during their TORS-assisted endoscopic procedure. The mean (SD) size of the identified mucosal primary lesions was 1.3 (0.1) cm. All mucosal primaries, when found, originated in the oropharynx including the base of tongue in 28 patients (58%), palatine tonsil in 18 patients (38%), and glossotonsillar sulcus in 2 patients (4%). Among patients in this study, 40 (67%) did not receive chemotherapy, and 15 (25%) did not receive radiation therapy. Conclusions and Relevance: Advances in transoral surgical techniques have helped identify occult oropharyngeal malignancies that traditionally have been treated with comprehensive radiation to the entire pharyngeal axis. We demonstrate the efficacy of a TORS-assisted approach to identify and surgically treat the primary tumor in patients presenting with CUP. In addition, patients managed with the TORS-assisted endoscopic approach benefit from surgical and pathological triage, which in turn results in deintensification of treatment by eliminating the need for chemotherapy in the majority of patients, as well as avoiding radiation therapy in select patients.

Intraoperative identification of the human communicating nerve during thyroidectomy.

The human communicating nerve (HCN) is a connection between the superior and recurrent laryngeal nerves that has been described in cadaveric studies. We report a case of an extralaryngeal variant of the HCN that was identified and stimulated intraoperatively during thyroidectomy. This appears to be the first case of intraoperative identification of this anatomic variant, of which the functional significance remains unclear.

Objective endoscopic findings in patients with recurrent croup: 10-year retrospective analysis.

OBJECTIVE: (1) To determine the incidence and severity of subglottic stenosis on endoscopic evaluation in a pediatric population of patients with recurrent croup. (2) To determine the incidence of abnormal findings on bronchoalveolar lavage and esophageal biopsy in a pediatric population with recurrent croup. METHODS: Case series with historical chart review of clinical data for pediatric patients (age ≤18 years) at a tertiary care children's hospital who underwent endoscopic evaluation of the upper aerodigestive tract with a diagnosis of recurrent croup over a ten-year period (2002-2012). Subglottic stenosis was graded on Myer-Cotton scale. Lipid-laden macrophages on bronchoalveolar lavage were noted as none/small/moderate/large with evidence of reflux noted as moderate or large. Esophageal biopsy specimens were evaluated for evidence of esophagitis. Data is expressed as mean±SEM. RESULTS: 1825 charts were reviewed of which 197 met inclusion criteria. Mean age at endoscopy was 53±3 months. Subglottic stenosis was noted in 41 patients (20.8%) with 95.1% being mild or Grade I. Abnormal findings on bronchoalveolar lavage were noted on 9.5% of bronchoalveolar lavage specimens. Abnormal esophageal biopsies were noted on 19.9% of specimens. Esophagitis was noted on 8.8% of biopsy specimens. CONCLUSIONS: Subglottic stenosis is a risk factor for recurrent croup. Evidence suggestive of reflux may be noted on bronchoalveolar lavage or esophageal biopsy, but these findings may not correlate with subglottic stenosis in recurrent croup patients.

Case Report: retained gutta-percha as a cause for persistent maxillary sinusitis and pain.

Dental sources of infection can produce acute and chronic maxillary sinusitis. In some cases, the source of the infection may be related to the presence of endodontic materials in the oral cavity. In this article, we report a case of retained gutta-percha in the maxillary sinus resulting in chronic sinusitis.

Attenuated PGI2 synthesis in obese Zucker rats.

In obesity, skeletal muscle blood flow during exercise (functional hyperemia) is impaired. We have indirectly demonstrated that an altered arachidonic acid metabolism is responsible for the impaired functional vasodilation in the obese Zucker rat (OZR), a model of obesity. In this study, we tested the hypothesis that there is an impaired release of PGI(2) due to a nitration of PGI(2) synthase (PGIS), which is associated with a decreased prostanoid receptor expression. PGI(2), PGE(2), and thromboxane A(2) (TXA(2)) release were determined in vitro using ELISA under basal conditions and in response to arachidonic acid (AA) administration (50 microM). Immunofluorescence of PGI(2) and TXA(2) receptors (IP and TP, respectively) was determined in dispersed vascular smooth muscle cells (VSMCs). Nitration of tyrosine residues of the PGIS enzyme was determined using immunoprecipitation and Western blot analysis. Following AA administration, PGI(2) and PGE(2) release were attenuated in OZR compared with lean Zucker rats (LZR; controls). Basal and AA-induced TXA(2) release were not significantly different between groups. IP and TP immunofluorescence were not significantly different between OZR and LZR groups. OZR exhibited elevated nitration of tyrosine residues of PGIS compared with LZR. These results suggest that alterations in the PGI(2) pathway (attenuated PGI(2) synthesis), and not the TXA(2) pathway (normal TXA(2) synthesis/no change in TP receptor expression), underlie the attenuated functional hyperemia in the OZR.

K(ATP)-mediated vasodilation is impaired in obese Zucker rats.

OBJECTIVE: Skeletal muscle blood flow during exercise is impaired in obesity. We tested the hypothesis that the attenuated vasodilation in skeletal muscle arterioles of obese Zucker rats (OZR) is due to altered K(ATP) channel-mediated vasodilation. MATERIALS AND METHODS: K(ATP) channel function was determined in isolated skeletal muscle arterioles in response to the K(ATP) opener cromakalim (0.1-10 microM) during normal myogenic tone and alpha-adrenergic-mediated tone (0.1 microM phenylephrine). The spinotrapezius muscle was prepared and the vasodilatory responses to muscle stimulation or iloprost (0.028-2.8 microM) were observed before and after the application of the K(ATP) inhibitor, glibenclamide (10 microM). Channel subunit expression was determined by using western blot analyses. RESULTS: Cromakalim concentration-response curves were shifted in OZR as compared to lean controls. OZR exhibited impaired functional and iloprost-induced vasodilation as compared to the lean controls. Glibenclamide inhibited the functional and iloprost-induced dilation in the lean rats with no effects in the obese a nimals. Channel subunit expression was similar in femoral arteries. CONCLUSION: The impaired functional vasodilation in the OZR is associated with altered K(ATP) channel sensitivity.

Regulation of muscle blood flow in obesity.

Obesity has been shown to impair muscle blood flow in humans. Vasodilatory control mechanisms such as metabolic control, myogenic mechanisms, conducted vasodilation, and release of endothelium-derived factors may be impaired in obesity due to insulin resistance, hyperglycemia, dyslipidemia, inflammation, oxidative stress, and endothelial dysfunction. The physiological importance of these blood flow control mechanisms has predominately been determined during the increase in blood flow (functional hyperemia) that occurs in response to the increased metabolism associated with exercise. This review examines the mechanisms by which functional hyperemia may be impaired in obesity and indicates areas where further studies are needed. The most extensively studied area of obesity-induced changes in muscle blood flow has been the role of endothelium-derived mediators during resting blood flow and exercise-induced hyperemia. Elevations in oxidative stress alter endothelium-derived factors, resulting in impaired vasodilatory responses. Alterations in metabolic and conducted vasodilatory regulation of blood flow have not been extensively studied in obesity, providing a potential area of research.

Altered arachidonic acid metabolism impairs functional vasodilation in metabolic syndrome.

These studies tested the hypothesis that in obese Zucker rats (OZRs), a model of metabolic syndrome, the impaired functional vasodilation is due to increased thromboxane receptor (TP)-mediated vasoconstriction and/or decreased prostacyclin-induced vasodilation. Spinotrapezius arcade arterioles from 12-wk-old lean (LZR) and OZR were chosen for microcirculatory observation. Arteriolar diameter (5 LZR and 6 OZR) was measured after 2 min of muscle stimulation in the absence or presence of 1 microM SQ-29548 (TP antagonist). Additionally, arteriolar diameter (6 for each group) was measured after application of iloprost (prostacyclin analog; 0.28, 2.8, and 28 microM), arachidonic acid (10 microM), and sodium nitroprusside (0.1, 1, and 10 microM) in the absence or presence of 1 microM SQ-29548. A 10 microM concentration of adenosine was used to induce a maximal dilation. Basal diameters were not different between LZRs and OZRs. Functional hyperemia and arachidonic acid-mediated vasodilations were significantly attenuated in OZR compared with LZR, and treatment with 1 microM SQ-29548 significantly enhanced the dilations in OZRs, although it had no effect in LZRs. Vasodilatory responses to iloprost and sodium nitroprusside (1 and 10 microM) were significantly reduced in OZR. Adenosine-mediated vasodilation was not different between groups. These results suggest that the impaired functional dilation in the OZR is due to an increased TP-mediated vasoconstriction and a decreased PGI2-induced vasodilation.