bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship between the ITCZ and MJO Initiation over the Indian Ocean
Authors: Zelinsky Rachel C. , Zhang Chidong , Liu Chuntao
Published: May 2019

Understanding convective initiation of the Madden–Julian oscillation (MJO) remains an unmet challenge. MJO initiation has been perceived as a process starting from a convectively suppressed large-scale condition with gradual growth of shallow convection to congestus and to deep convective and stratiform systems that cover a large-scale area. During the DYNAMO field campaign over the Indian Ocean, MJO initiation was observed to start from an existing intertropical convergence zone (ITCZ) south of the equator. This raises a question of what possible role the ITCZ may play in convective initiation of the MJO. This study addresses this question through analysis of satellite observations of precipitation and a global reanalysis product. By setting several criteria, MJO and ITCZ events were objectively identified and grouped according to whether MJO initiation was immediately preceded by an ITCZ. The results demonstrate that an ITCZ is neither a necessary nor sufficient condition for convective initiation of the MJO. Nonetheless, evolution of the large-scale circulation, moisture, and convective characteristics during MJO initiation can be different with and without a preexisting ITCZ. Convective growth begins gradually before and during MJO initiation when there is a preexisting ITCZ whereas it is abrupt and slightly delayed without a preexisting ITCZ. Such differences are presumably related to the existing large-scale moist condition of the ITCZ. The results from this study suggest that there are multiple mechanisms for convective initiation of the MJO, which should be considered in theoretical understanding of the MJO.
Characteristics and Variations of Low-Level Jets and Environmental Factors Associated with Summer Precipitation Extremes over the Great Plains
Authors: Hodges Derek , Pu Zhaoxia
Published: May 2019

Low-level jets (LLJs) are associated with 10%–45% of the summer precipitation in the U.S. Great Plains region (GPR). This study uses the NCEP North American Regional Reanalysis data product (1979–2017) to characterize the association between LLJs and precipitation extremes (anomalously wet versus dry) during the summer months (June–August) over the GPR. It is found that the number, distribution, and direction of LLJs are not clearly associated with the precipitation anomalies. The characteristics and structural variations of the LLJs and their large-scale and mesoscale environment are then examined to identify the links between LLJs and precipitation extremes. Results show that dry and wet summers vary by synoptic anomaly patterns. During dry summers the anomalous ridging results in a warmer and drier environment, primarily through subsidence, which inhibits precipitation near LLJs. In contrast, during wet summers, a reduction in subsidence occurs, resulting in stronger lift and a cooler and moister environment, which leads to enhanced precipitation near LLJs. The LLJ speed, orientation, and spatial properties vary according to the synoptic anomaly patterns. LLJs do not drive precipitation extremes, but instead, they respond to them. Specifically, the LLJ exit region is characterized by stronger baroclinity and higher moisture content during the wet years. The higher moisture content allows for ascending air parcels to reach saturation more quickly, while the stronger baroclinity increases the warm advection associated with the LLJ. This, in turn, leads to faster rising motion and is therefore closely associated with the location and intensity of the LLJ associated precipitation.
Frontogenesis and Variability in Denmark Strait and Its Influence on Overflow Water
Authors: Spall Michael A. , Pickart Robert S. , Lin Peigen , Appen Wilken-Jon von , Mastropole Dana , Valdimarsson H. , Haine Thomas W. N. , Almansi Mattia
Published: May 2019

A high-resolution numerical model, together with in situ and satellite observations, is used to explore the nature and dynamics of the dominant high-frequency (from one day to one week) variability in Denmark Strait. Mooring measurements in the center of the strait reveal that warm water “flooding events” occur, whereby the North Icelandic Irminger Current (NIIC) propagates offshore and advects subtropical-origin water northward through the deepest part of the sill. Two other types of mesoscale processes in Denmark Strait have been described previously in the literature, known as “boluses” and “pulses,” associated with a raising and lowering of the overflow water interface. Our measurements reveal that flooding events occur in conjunction with especially pronounced pulses. The model indicates that the NIIC hydrographic front is maintained by a balance between frontogenesis by the large-scale flow and frontolysis by baroclinic instability. Specifically, the temperature and salinity tendency equations demonstrate that the eddies act to relax the front, while the mean flow acts to sharpen it. Furthermore, the model reveals that the two dense water processes—boluses and pulses (and hence flooding events)—are dynamically related to each other and tied to the meandering of the hydrographic front in the strait. Our study thus provides a general framework for interpreting the short-time-scale variability of Denmark Strait Overflow Water entering the Irminger Sea.
Involvement of TNF-α and IFN-γ in Inflammation-Mediated Cochlear Injury
Authors: Moon Sung K. , Woo Jeong-Im , Lim David J.
Published: May 2019

Objectives:

Inflammation is crucial for the pathogenesis of acquired sensorineural hearing loss, but the precise mechanism involved remains elusive. Among a number of inflammatory mediators, tumor necrosis factor-alpha (TNF-α) plays a pivotal role in cisplatin ototoxicity. However, TNF-α alone is cytotoxic to cochlear sensory cells only at the extremely high concentrations, suggesting the involvement of other factors that may sensitize cells to TNF-α cytotoxicity. Since interferon gamma (IFN-γ) importantly contributes to the cochlear inflammatory processes, we aim to determine whether and how IFN-γ affects TNF-α cytotoxicity to cochlear sensory cells.

Methods:

TNF-α expression was determined with western blotting in RSL cells and immunolabeling of mouse temporal bone sections. HEI-OC1 cell viability was determined with MTT assays, cytotoxicity assays, and cytometric analysis with methylene blue staining. Cochlear sensory cell injury was determined in the organotypic culture of the mouse organ of Corti.

Results:

Spiral ligament fibrocytes were shown to upregulate TNF-α in response to pro-inflammatory stimulants. We demonstrated IFN-γ increases the susceptibility of HEI-OC1 cells to TNF-α cytotoxicity via JAK1/2-STAT1 signaling. TNFR1-mediated Caspase-1 activation was found to mediate the sensitization effect of IFN-γ on TNF-α cytotoxicity. The combination of IFN-γ and TNF-α appeared to augment cisplatin cytotoxicity to cochlear sensory cells ex vivo.

Conclusions:

Taken together, these findings suggest the involvement of IFN-γ in the sensitization of cochlear cells to TNF-α cytotoxicity, which would enable us to better understand the complex mechanisms underlying inflammation-mediated cochlear injury.
The Role of Female Directors in the Boardroom: Examining Their Impact on Competitive Dynamics
Authors: D. Kolev Kalin , Hughes-Morgan Margaret , Rehbein Kathleen
Published: May 2019

This study contributes simultaneously to research on women board members and competitive dynamics by investigating two unresolved research questions: What is the effect of female directors on the firm’s competitive repertoire? Under what conditions is this effect more pronounced? Leveraging the “Awareness-Motivation-Capability” (AMC) framework, we predict that having women on the board of directors should impact the complexity, heterogeneity, and volume of the firm’s competitive moves. Relying upon a sample of U.S. pharmaceutical firms for the years 2000 to 2017, we find that adding female directors on the board positively affects the complexity and volume of a firm’s competitive moves, but negatively impacts the heterogeneity of competitive actions. In addition, the presence of a female CEO moderates these effects, leading to more complex competitive actions and increased volume. Thus, our study lends a greater understanding of how female board members influence competitive dynamics and shape the strategic direction of the firm.
Experimental and molecular dynamics study of boron nitride nanotube-reinforced polymethyl methacrylate composites
Authors: Sharma Sumit , Setia Prince , Chandra Rakesh , Thakur Nitin
Published: May 2019

Heat dissipation is very essential for the efficient working of electronic devices. There is a widespread demand for high thermal conductivity materials. Boron nitride nanotubes have high thermal conductivity but due to their poor interfacial adhesion with polymers, their use as heat dissipating material is restricted. In this study, a silane-coupling agent has been used to modify the boron nitride nanotubes. These tubes were then inserted in polymethyl methacrylate matrix. Various properties such as thermal conductivity, storage modulus, and loss factor have been predicted. Molecular dynamics simulations have also been used for accurate prediction of the properties of boron nitride nanotubes/polymethyl methacrylate composites. The boron nitride nanotubes weight percentage was varied from 0% to 70% for studying the effect on thermal conductivity, storage modulus, and loss factor. The experimentally obtained thermal conductivity increased rapidly from 0.6 W/mK at 40 wt.% of boron nitride nanotubes to about 3.8 W/mK at 80 wt.% of boron nitride nanotubes in polymethyl methacrylate matrix (an increase of nearly 533%). A similar trend was obtained using molecular dynamics simulations. The storage modulus increased from 2 GPa (for pure polymethyl methacrylate) to about 5 GPa (for 70 wt.% boron nitride nanotubes). The glass transition temperature of boron nitride nanotubes/polymethyl methacrylate composites shifted to higher temperatures with an increase in boron nitride nanotubes weight percentage.
MRI Video Diagnosis and Surgical Therapy of Soft Tissue Trauma to the Craniocervical Junction
Authors: Voile Eckhard , Montazem Abbas
Published: May 2019

We evaluated objective diagnostic methods for patients with possible upper cervical spine instability caused by trauma and correlated them with subsequent neurosurgical findings and outcomes. Between November 1995 and May 1998, we investigated 420 patients with functional magnetic resonance imaging (MRI) of the craniocervical junction. We evaluated the extracranial vertebral circulation by MRI angiography, with focus on the position of the dens and on the subarachnoid space during entire rotational maneuvers. We documented 72 cases (17.1%) of injuries to the alar ligaments that were accompanied by signs of instability. Twenty patients (4.8%) had a complete alar ligament rupture, and 52 (12.4%) had an incomplete rupture with coexisting instability. We referred these patients to a neurosurgeon. Surgery was eventually chosen for 42 patients (10.0%) with the intention of obtaining dorsal occipitocervical stabilization. The duration of time between the MRI evaluation and surgery ranged from 1 week to 1.5 years (mean: 3.5 mo). After the fifth postoperative day, almost all symptoms had disappeared. One year following surgery, 34 of the 42 patients (80.9%) still demonstrated successful fusion and an alleviation of their sensation of instability. Twenty-five of these patients (59.5%)—all of whom were unemployed before surgery—were able to resume a professional activity. In the eight patients (19.0%) who still had a loss of stability during the second and 14th weeks, we noticed that there were some negative effects of rehabilitation. Six of these patients developed pseudarthrosis or osteolysis of their bone grafts during the first 3 months after fusion, and three required a repeat operation. We conclude that functional MRI with lateral tilting and rotatory evaluation is a useful tool for investigating craniocervical instability. For patients who are recalcitrant to following a program of conservative therapy, surgical stabilization of the craniocervical junction appears to be justified.
Head and Neck Granulocytic Sarcoma with Acute Myeloid Leukemia: Three Rare Cases
Authors: Çankaya Hakan , Ugras Serdar , Dilek Imdat
Published: May 2019

We conducted a retrospective review of pathology files and hospital records and identified three unusual presentations of granulocytic sarcoma associated with acute myeloid leukemia (AML) of the head and neck. At least one mass was observed on the skin of all three patients. A 17-year-old boy had masses in each temporal region that were accompanied by bilateral facial paralysis. He was administered chemotherapy and radiotherapy, but he died of infection secondary to a second relapse 29 months after the initial diagnosis. A 17-year-old girl had a tumor in the right parotid area. She received chemotherapy, but she died of infection and bleeding 2 months after the initial diagnosis. A 33-year-old man had numerous tumors widely disseminated over his skin. He received chemotherapy and was in remission 12 months after the initial diagnosis, but he eventually relapsed and died. Granulocytic sarcoma can be localized in unexpected regions, including the head and neck. This tumor is very often misdiagnosed as a malignant lymphoma, which leads to delayed treatment and a poor outcome. Therefore, clinical and histopathologic findings should be evaluated before any diagnosis of malignant lymphoma is pronounced. Immunohistochemical stains should also be performed on patients with suspected granulocytic sarcoma, and aggressive chemotherapy or immunotherapy should be administered. We believe that high-dose chemotherapy can improve survival rates in granulocytic sarcoma associated with AML.
A Case of Parotid Mucoepidermoid Carcinoma Complicated by Fatal Gastrointestinal Bleeding
Authors: To Edward W.H. , Tsang Wai-Ming , Pang Peter C.W. , Cheng Jack H.H. , Tse Gary M.K. , Tsang Willis S.S.
Published: May 2019

Mucoepidermoid carcinoma is one of the most common of the salivary gland neoplasms. Histologically, it is classified as either a low-, intermediate-, or high-grade tumor, and there are significant differences in prognosis among the different grades. Patients with low-grade disease have an excellent chance of survival. High-grade tumors behave aggressively, and they frequently manifest as local recurrences and distant metastases. We describe a case of a high-grade mucoepidermoid carcinoma of the parotid gland that had metastasized to the skin, stomach, and liver. The disease culminated in a rapidly fatal bleeding from the stomach metastasis. Such a complication is unusual and to our knowledge has not been previously reported. We briefly discuss the clinical features, biologic behavior, and treatment of this tumor.
Pneumolabyrinth: A Late Complication of Stapes Surgery
Authors: Scheid Sara C. , Feehery John M. , Willcox Thomas O. , Lowry Louis D.
Published: May 2019

As temporal bone imaging techniques continue to improve, it is likely that we will see an increase in the detection of pneumolabyrinth. Several mechanisms have been proposed to explain how air enters the labyrinth. A small number of authors has reported an association between pneumolabyrinth and temporal bone fractures, perilymphatic fistulae, and displaced stapes prostheses. In this article, we describe a new case of pneumolabyrinth that was seen as a late complication of stapes surgery, and we summarize what is known about this rare condition.
Malignant Lymphoepithelial Lesion of the Parotid Gland: A Case Report and Review of the Literature
Authors: Wu Derrina Ling-Ling , Shemen Larry , Brady Terrence , Saw Daisy
Published: May 2019

Malignant lymphoepithelial lesions are rare tumors of the major salivary glands. They most often occur in Asians and Greenland Eskimos and are strongly associated with Epstein-Barr virus infection. We report a case of a malignant lymphoepithelial lesion of the parotid gland that developed in an Italian-American woman whose serology was positive for Epstein-Barr virus antibody. The patient underwent a left total parotidectomy and upper neck dissection, followed by radiation therapy. At the 2-year follow-up, she remained free of disease.
Sphenoid Sinus Mucocele: A Rare Complication of Transsphenoidal Hypophysectomy
Authors: Buchinsky Farrel J. , Gennarelli Thomas A. , Strome Scott E. , Deschler Daniel G. , Hayden Richard E.
Published: May 2019

Only seven cases of a sphenoid mucocele occurring after transsphenoidal hypophysectomy have been previously reported in the world literature. In this article, we report a new case, which occurred in a 67-year-old man. The sphenoid sinus mucocele developed 12 years following transsphenoidal hypophysectomy and adjunctive radiotherapy. The patient was successfully managed with incision and drainage. Although transsphenoidal hypophysectomy is a common operation, this particular complication appears to be rare or at least under-reported. Sphenoid sinus mucocele deserves consideration in the differential diagnosis of a sphenoidal parasellar mass in a patient who has undergone an earlier transsphenoidal hypophysectomy.
Target-specific Multimodality Endovascular Management of Carotid Artery Blow-Out Syndrome
Authors: Levy Elad I. , Horowitz Michael B. , Koebbe Christopher , Jungreis Charles C.
Published: May 2019

We describe a novel multimodality endovascular approach to safely control hemorrhage from a carotid artery pseudoaneurysm and tumor vasculature associated with a squamous cell carcinoma. This approach was used in the case of a 68-year-old man who had previously undergone a laryngectomy, chemotherapy, and brachytherapy and who subsequently experienced acute oropharyngeal bleeding. Angiography detected a carotid artery pseudoaneurysm and significant tumor vascularity. A target-specific multimodality approach was taken to embolize the potential etiologies for both the current and any future hemorrhages. Stent-assisted coiling of the pseudoaneurysm was successful. The tumor blush was treated with polyvinyl alcohol particles and both retrievable and nonretrievable coils. Endovascular surgeons have become increasingly involved in the management of patients with carotid injuries and with neoplasms in and around the skull base. Current endovascular technology provides a rapid target-specific approach to the treatment of carotid artery blow-out syndrome and has a greater potential to lower morbidity than does carotid sacrifice.
Pressure-specifying Sensory Device: Quantitative Sensory Measurement in the Oral Cavity and Oropharynx of Normal Adults
Authors: Sinha Uttam K. , Rhee John , Alcaraz Nelson , Urken Mark L.
Published: May 2019

We conducted a study to quantitatively determine the pressure perception thresholds in the oral cavity and oropharynx of a normal population with the Pressure-Specifying Sensory Device (PSSD). The PSSD measured pressure perception thresholds for both static and moving one- and two-point discrimination modalities at a variety of sites in the oral cavity and oropharynx as well as in the forearm of 11 adults. We also evaluated the ability of the PSSD to enhance sensory discrimination in four of these subjects by the process of sensory re-education for 11 days over a 15-day period. We found that the buccal mucosa and the tongue tip were the most sensitive sites in the oral cavity and oropharynx and that the floor of the mouth and the soft palate were the least sensitive. Sensory discrimination in the oral cavity was enhanced in all four subjects who underwent sensory re-education, although it returned to baseline levels over time after re-education was discontinued. The degree of intra- and intertester variability was minimal. Our data can be used as an aid in the development of techniques to surgically restore sensation in the oral cavity and oropharynx.
A Case of Giant Sialolith of the Submandibular Salivary Gland
Authors: Yildirim Altan
Published: May 2019

Sialolithiasis is the most common disease of the salivary glands. This report describes the case of a patient who had an unusually large submandibular gland sialolith that was completely encased in the glandular substance. The author describes the management of this patient and reviews the literature.
Laryngeal Rhinosporidiosis: Report of a Rare Case
Authors: Kumar Suresh , Mathew John , Cherian Varghese , Rozario Rekha , Kurien Mary
Published: May 2019

Extranasal manifestations of rhinosporidiosis are relatively uncommon. Laryngeal involvement is extremely rare, as only 3 cases have been previously reported. We describe a new case, which occurred in a patient with coexisting nasal rhinosporidiosis who presented with inspiratory stridor. Both lesions were completely excised under general anesthesia without the need for preliminary tracheostomy.
Pediatric Intracapsular Tonsillectomy with Bipolar Electrosurgical Scissors
Authors: Isaacson Glenn
Published: May 2019

This article describes the benefits of performing intracapsular tonsillectomy with bipolar electrosurgical scissors as an alternative to the powered microdebrider. These scissors are used to excise approximately 90% of the tonsillar mass en bloc. The remaining tonsillar tissue is electrodesiccated by monopolar suction cautery, while the anterior and posterior pillars are completely preserved. The procedure leaves a smaller surgical wound than do extracapsular techniques. Surgical time averages 6 minutes. There is typically no intraoperative blood loss. Bipolar electrosurgical scissors are an efficient and low-cost tool for performing pediatric intracapsular tonsillectomy.
Harmonic Scalpel Tonsillectomy versus Hot Electrocautery and Cold Dissection: An Objective Comparison
Authors: Shinhar Shai , Scotch Brett M. , Belenky Walter , Madgy David , Haupert Michael
Published: May 2019

We conducted a large-scale retrospective study to compare the surgical efficacy, practical utility, safety, and cost-effectiveness of ultrasonic harmonic scalpel tonsillectomy, hot electrocautery, and cold surgical dissection. We based our findings on the length of operating time, complication rates, the length of hospital stay for patients with complications, and relative costs. We then compared our findings with those published in earlier reports, none of which were based on a three-way comparison. Our study population was made up of 316 patients—175 males and 141 females aged 1 to 23 years (mean: 7.3)—who had undergone adenotonsillectomy or tonsillectomy alone at our tertiary care children's hospital between Sept. 1, 2000, and Aug. 31, 2001. The harmonic scalpel was used on 75 patients (23.7%), electrocautery on 109 patients (34.5%), and cold surgical dissection on 132 (41.8%). The mean length of operating time for adenotonsillectomy was 42.4 (n = 70), 43.0 (n = 103), and 49.2 (n = 95) minutes, respectively; the corresponding times for tonsillectomy alone were 23.6 (n = 5), 30.2 (n = 6), and 35.3 (n = 37) minutes. Overall complication rates were 2.7, 5.5, and 6.1%, respectively. Hospital stays for immediate (<24 hr) postoperative bleeding averaged 2.0, 1.0, and 0.7 days, respectively, and stays for dehydration averaged 1.0, 1.3, and 1.5 days. Mean per-patient institutional costs were $460.00, $310.75, and $300.00, respectively. We conclude that harmonic scalpel tonsillectomy is efficacious, practical, safe, and cost-effective, and we recommend that any institution involved with a significant number of pediatric tonsillectomies consider using it.
Metastasis of Colonic Adenocarcinoma to the External Ear Canal: An Unusual Case with a Complex Pattern of Disease Progression
Authors: Carson Henry J. , Krivit Jeffrey S. , Eilers Stanley G.
Published: May 2019

We report on a patient who developed far-ranging metastases of adenocarcinoma of the colon that followed a gradual cephalad progression, including the right external ear canal, and led to hearing loss. The patient was a 63-year-old white male with stage III adenocarcinoma of the colon. After 2 years with metastases elsewhere, he developed hearing loss on the right side. Physical examination of the head and neck showed a mass in the external ear canal, and biopsy confirmed adenocarcinoma. After removal, the patient's hearing improved. This case is interesting not only because of the unusual metastasis to the external ear canal, but also because of the patient's previous history of metastasis over the course of more than 2 years. The significance of such wide-ranging metastases is that metastasis of adenocarcinoma to the ear did not signal imminent death, and relief of the hearing loss it caused was possible.
Primary Non-Hodgkin's Lymphoma of the Frontal Sinus: Case Report and Review of the Literature
Authors: Neves Maura C. , Lessa Marcus M. , Voegels Richard L. , Butugan Ossamu
Published: May 2019

Non-Hodgkin's lymphoma of the sinonasal tract is an uncommon lesion, representing 1.5 to 15% of all lymphomas. Most cases of primary non-Hodgkin's lymphoma of the sinonasal tract occur in the maxillary sinus, ethmoid sinus, and nasal cavity; its occurrence in the frontal sinus is extremely rare. We report a case of primary type B non-Hodgkin's lymphoma of the frontal sinus in a 43-year-old man. The patient complained of frontal headaches that had not improved with analgesic drugs, and he presented with a frontal bulge that involved the left upper eyelid; the bulge had progressively enlarged over a 3-month period. A biopsy of the mass identified the type B non-Hodgkin's lymphoma. Immunohistochemical study not only confirmed the histologic type of the tumor, it also provided some important information about the primary tumor site. Advances in immunohistochemistry have shown that type B non-Hodgkin’s lymphoma is more common in North American and European patients, whereas subtype T is more common in Asians and in some Latin Americans. The treatment of this condition is still controversial, but the combination of radiotherapy and chemotherapy has yielded the best results in all stages of the disease.
Peritonsillar Abscess: A Comparison of Outpatient IM Clindamycin and Inpatient IV Ampicillin/Sulbactam following Needle Aspiration
Authors: Ozbek Cem , Aygenc Erdinc , Unsal Evrim , Ozdem Cafer
Published: May 2019

In an attempt to assess the effect of antibiotic choice on the treatment of peritonsillar abscess, we compared the clinical efficacy of empiric intramuscular clindamycin and intravenous ampicillin/sulbactam (following needle aspiration of the abscess) in a prospective, randomized study of 58 patients. Patients in the clindamycin group were treated on an outpatient basis, whereas those in the ampicillin/sulbactam group were hospitalized for the duration of their treatment (minimum: 7 days). Comparison of clinical outcomes with respect to the posttherapeutic duration of fever and throat pain and the time to resumption of eating revealed no statistically significant difference between the two groups. These results suggest that intramuscular clindamycin is an excellent choice and can be safely prescribed on an outpatient basis following needle aspiration, thereby reducing both antibiotic and hospital costs.
Electrophysiologic Laryngeal Nerve Monitoring in High-Risk Thyroid Surgery
Authors: Song Phillip , Shemen Larry
Published: May 2019

We recently began performing intraoperative electrophysiologic monitoring of the recurrent laryngeal nerve and the external branch of the superior laryngeal nerve during high-risk thyroidectomies. Neuromonitoring can detect stimulation of these nerves and thereby prevent a mechanical or thermal injury that can result in neurapraxia or axonotmesis. Monitoring is also useful during dissection in an already operated-on field, when performing thyroidectomy on patients who depend on their voice for their livelihood, and when removing a large goiter or mediastinal mass.
Schwannoma of the Larynx: A Case Report
Authors: Syeda Farahnaz , Hussain Akhtar
Published: May 2019

Neurogenic tumors of the larynx are rare. We report a case of supraglottic schwannoma in a 59-year-old woman. We excised the tumor via a lateral thyrotomy approach.
Airway Obstruction by Granulation Tissue within a Fenestrated Tracheotomy Tube: Case Report
Authors: Carron Michael A. , Kim Sihun Alex , Sawhney Raja , Reidy Patrick
Published: May 2019

Complications of tracheotomy tube placement can be categorized as intraoperative, early postoperative, and late postoperative. Among the late complications is the development of granulation tissue. We describe one of the few reported cases of granulation tissue that formed within a fenestrated tracheotomy tube. In this case, the granulation tissue grew through the fenestrations, obliterated the tracheal lumen, and tethered the tube to the trachea itself. As a result, the patient required emergency treatment to restore airway patency.
Underlay Tympanoplasty with Laser Tissue Welding
Authors: Foyt David , Slattery William H. , Carfrae Matthew J.
Published: May 2019

We investigated the feasibility of using laser tissue welding techniques to perform transcanal underlay tympanoplasty. We used 10 temporal bones obtained from human cadavers. After creating a subtotal tympanic membrane perforation, we introduced harvested periosteum through the perforation and used laser tissue welding to secure the periosteum graft in place in an underlay fashion. The procedure was performed via a transcanal approach and did not require middle ear packing. Immediately after the graft had been placed, we qualitatively tested its integrity with a blunt probe. The graft was as strong as the native cadaver tympanic membrane in all 10 cases. We conclude that laser transcanal underlay tympanoplasty is a feasible and effective method of repairing a tympanic membrane. The ultimate goal is to develop a technique that will allow physicians to routinely perform underlay tympanoplasty on moderately sized perforations in an office setting.
Role of Impacted Cerumen in Hearing Loss
Authors: Subha Sethu T. , Raman Rajagopalan
Published: May 2019

We performed a study to determine if cerumen in the ear canal causes significant hearing loss and to ascertain if there is any correlation between the amount of cerumen and the degree of hearing loss. Our study was conducted on 109 ears in 80 patients. The results indicated that impacted cerumen does cause a significant degree of conductive hearing loss. We found no significant correlation between the length of the cerumen plug and the severity of hearing loss. Nor did we find any significant correlation between the presence of impacted cerumen and variables such as age, sex, ethnicity, or affected side.
The Prevalence of Samter's Triad in Patients Undergoing Functional Endoscopic Sinus Surgery
Authors: Kim Ji-Eon , Kountakis Stilianos E.
Published: May 2019

We conducted a retrospective study to determine the prevalence of Samter's triad (nasal polyps, asthma, and aspirin sensitivity) in 208 consecutively presenting patients who had undergone functional endoscopic sinus surgery (FESS) for chronic rhinosinusitis from September 2001 through August 2003. Overall, Samter's triad was found in 10 patients (4.8%); subgroup analyses showed that the prevalence of Samter's triad was 5.9% in adults, 9.4% in patients with nasal polyps alone, 16.9% in patients with asthma alone, and 25.6% among patients with both polyps and asthma. On average, patients with Samter's triad had undergone approximately 10 times as many previous FESS procedures as had the patients without Samter's triad (mean: 5.2 vs. 0.53; p < 0.001). In addition to Samter's triad, four other factors were independently and significantly associated with a higher number of previous FESS procedures: nasal polyps alone, asthma alone, both polyps and asthma, and cystic fibrosis alone. Finally, at 6 months following their most recent surgery, patients with Samter's triad had significantly higher rates of symptom recurrence (nasal obstruction, facial pain, postnasal drip, and anosmia) and a recurrence of nasal polyps.
A Comparison of Outcomes following Tympanostomy Tube Placement or Conservative measures for Management of Otitis Media with Effusion
Authors: Diacova Svetlana , McDonald Thomas J.
Published: May 2019

We obtained the charts of 183 patients (197 ears) who had undergone surgery for chronic otitis media (COM), and we reviewed their otic histories to analyze the series of events that ultimately culminated in surgery. All ears had originally been treated for otitis media with effusion (OME); 125 ears had been treated with tympanostomy tube placement, and 72 ears had been treated with conservative measures. Our goal was to compare the influence that these two strategies had on the subsequent development of COM and its sequelae (i.e., retraction pockets, tympanic membrane perforations, and cholesteatomas) and thereby determine which strategy is preferable. We found that although retraction pockets developed in a significantly higher proportion of the tympanostomy-treated ears than the conservatively treated ears (58 vs. 35%; p < 0.01), a significantly greater percentage of retractions in the tympanostomy-treated ears were mild and situated in the anterior part of the tympanic membrane (52 vs. 32%; p < 0.05). Moreover, severe retractions were significantly more common in the conservatively treated ears (40 vs. 16%; p < 0.02); the incidence of complete retractions in the two groups of ears was similar (tympanostomy: 32%; conservative treatment: 28%). Cholesteatomas developed in a significantly lower percentage of tympanostomy-treated ears (67 vs. 81%; p < 0.05), and the incidence of large cholesteatomas that involved the tympanic and mastoid cavities was likewise significantly lower in these ears (44 vs. 69%; p < 0.05). There was no significant difference in the incidence of tympanic membrane perforations. Finally, even though all of these ears eventually required surgery for COM, the tympanostomy-treated ears required significantly fewer repeat surgeries (16 vs. 28%; p < 0.05) and significantly fewer radical modified tympanomastoidectomies (30 vs. 44%; p < 0.05). Therefore, we conclude that myringotomy with insertion of tympanostomy tubes to treat OME is superior to conservative treatment.
Safety and Efficacy of Pressure-assisted Tissue-welding Tonsillectomy: A Preliminary Evaluation
Authors: Michel Randall G. , Weinstock Bernard I. , Tsau Kang
Published: May 2019

We conducted a retrospective study of the safety and efficacy of a new pressure-assisted tissue-welding technology (ENTceps; Starion Instruments Corp.; Sunnyvale, Calif.) for total tonsillectomy, either alone or with adenoidectomy. The use of this instrument was compared in two groups of patients categorized by age. The younger group was made up of 50 patients aged 2 to 12 years who had undergone total tonsillectomy and adenoidectomy (T&A), and the older group was made up of 50 patients aged 13 to 47 years who had undergone either T&A or isolated total tonsillectomy. The primary safety endpoint was the presence or absence of intra- or postoperative complications—particularly the amount of intraoperative blood loss and the incidence of delayed postoperative bleeding. In each group, the mean amount of intraoperative blood loss was no more than 30 ml, and only 2 of the 100 patients experienced postoperative hemorrhage. Among the efficacy parameters were the amount of operating and recovery time and the postoperative appearance of the tonsillar fossae. The mean operating time was 13.0 minutes in the younger group and 19.5 minutes in the older group, and the mean total recovery times were 120.0 and 130.4 minutes, respectively; all tonsillar fossae were well epithelialized by 2 weeks after surgery. Finally, surgical morbidity was determined on the basis of the amount of perioperative pain medication administered, the number of unscheduled patient telephone contacts and clinic visits, and the amount of time needed to return to a normal diet and activities. Nine patients in the younger group and 6 in the older group required no pain medications during recovery; overall, pain was not a significant issue for most patients. Sixteen patients made a total of 20 telephone calls and 8 clinic visits prior to their scheduled postoperative appointment; almost all of these encounters dealt with postoperative pain. Only 1 patient, who had previously undiagnosed von Willebrand disease, had not returned to a normal diet and activities by the end of 1 week. Based on our preliminary findings—and a comparison of our results with those of other studies published in the literature relative to the amount of intraoperative bleeding, the incidence of postoperative bleeding, and operating times—we conclude that pressure-assisted tissue-welding technology is safe and compares favorably with other tonsillectomy techniques. This method of electrocautery is straightforward and relatively easy to learn.
Aortoesophageal Fistula: A Case Report
Authors: Tighe David , Wood Andy , Kale Savita
Published: May 2019

Patients with impacted foreign bodies in the upper aerodigestive tract present commonly to ENT clinics. This case report highlights two important issues in the management of these patients. First, if the evidence of esophageal perforation is strong and contrast swallow is negative, the physician must consider further imaging, such as contrast computed tomography. Second, ENT physicians must beware of the complications of esophageal trauma, including major vascular injury and aortoesophageal fistula, in patients with retained sharp foreign bodies in the mid-esophagus.
The Peak Flow Nasal Patency Index
Authors: Larsen Knud , Kristensen Søren
Published: May 2019

The peak flow nasal patency index (NPI) is the ratio between the nasal and oral peak airflow. This index was found to be a good indicator of nasal patency present in 24 patients following septoplasty and indicated significant improvement postoperatively. The peak flow nasal patency index was also correlated to self-assessment scores of nasal function in each patient. In this latter study, a low index correlated to a high self-assessment score, both of which indicated poor nasal patency. Our studies have shown that the peak flow nasal patency index is a useful measure for determining nasal patency, particularly for defining the results of any applied therapies.
Obstructive Sleep Apnea Syndrome: Pathophysiology, Upper Airway Evaluation and Surgical Treatment
Authors: Fujita Shiro
Published: May 2019

This paper describes the pathophysiology of the upper airway and the methods of evaluation which include mainly the Mueller maneuver, and cephalometrics. The management of Obstructive Sleep Apnea Syndrome (OSAS) is determined by the level of daytime dysfunction, the degree of cardiopulmonary complications, age, co-existing medical problems, life style, and the extent of the upper airway obstruction and abnormality. Continuous positive airway pressure (C-PAP), uvulopalatopharyngoplasty (UPPP), and permanent tracheostomy are procedures indicated depending on the severity of the case. Midline laser glossectomy was introduced as a new surgical procedure approach to the treatment of OSAS, as an alternative to maxillofacial surgery. When combined with UPPP, the successful results are improved.
Hemorrhage from Spontaneous Rupture of a Parathyroid Adenoma (A Case Report)
Authors: Amano Yoshiharu , Fukuda Ikuo , Mori Hiroshi , Kumoi Takeo
Published: May 2019

A case of extracapsular hemorrhage from spontaneous rupture of a parathyroid adenoma is reported. In the case presented here, adenoma was revealed by a sudden onset of a huge ecchymosis and hematoma of the entire anterior neck and right chest, causing recurrent nerve paresis. These cases of hemorrhage from rupture of silent parathyroid adenoma mimicking a dissecting thoracic aortic aneurysm are discussed.
Hearing Improvement following Removal of Acoustic Neuroma with Preoperative Sudden Deafness
Authors: Yanagihara Naoaki , Murakami Shingo , Asai Masanori , Hatakeyama Takao , Zenke Kiichiro
Published: May 2019

We report three cases of small intracanalicular acoustic tumor with sudden hearing loss (SHL). The tumors were totally removed through the middle cranial fossa approach, preserving both the facial and cochlear nerves between one and four months after the onset of deafness. From one to three months postoperatively hearing has improved significantly. Hearing improvement in acoustic tumor surgery is a new aspect to be studied more in the future. Although the data are insufficient to draw broad conclusions, surgical removal of small acoustic tumors is rational to improve hearing, reduce or eliminate tinnitus and prevent recurrent attacks of deafness or vertigo. Factors relevant to postoperative hearing improvement are considered.
Parathyroid Update: A Review of 220 Cases
Authors: Summers Gordon W.
Published: May 2019

A total of 220 patients have undergone cervical exploration for hyperparathyroidism by the author. A review of 125 cases was published in 1991. An additional 95 patients have been explored in the subsequent four years. Subtotal parathyroidectomy was performed in 39 patients with chronic renal failure. Exploration was successful in over 97% of the 181 patients diagnosed with primary hyperparathyroidism. Single adenomas were found in 146, double adenomas in 11, and multiple gland hyperplasia in 19 patients. Two of the five patients in whom cervical exploration failed were ultimately diagnosed with benign familial hypocalciuric hypercalcemia. Twenty-four adenomas were ectopic. Preoperative thallium-technetium scans and ultrasound correctly localized only 61% of the adenomas. Technetium sestamibi scans were correct in two of four adenomas. Only 47% of ectopic adenomas were correctly localized by isotope scanning and 29% by ultrasound.

All four glands should be examined at initial exploration. Because of the occurrence of double adenomas, contralateral exploration is always indicated regardless of whether an enlarged gland and a normal one are found on the first side. All enlarged parathyroids should be removed when dealing with single or multiple adenomas; subtotal parathyroidectomy (3-1/2 glands) should be performed in multiple gland hyperplasia. Frozen section confirmation of excised parathyroid tissue is essential. If exploration is unsuccessful, ectopic locations, such as the retroesophageal areas, thymus, anterior and posterior mediastinum, carotid sheath and thyroid lobe, must be examined carefully.

Preoperative localization studies are not as reliable as an experienced parathyroid surgeon.
Implantable Hearing Device Performance Measured by Laser Doppler Interferometry
Authors: Gan Rong Z. , Wood Mark W. , Ball Geoffrey R. , Dietz Timothy G. , Dormer Kenneth J.
Published: May 2019

Recent application of the Doppler principle laser interferometry to audiology, acoustics and otology has facilitated the development of implantable hearing devices (IHDs). During the design and testing of two different electromagnetic middle ear implants for sensorineural hearing loss, we used single-point laser Doppler interferometry (LDI). A commercially available interferometer, internally calibrated and validated against a National Institute for Standards and Technology (NIST) standard, was used with both mechanical fixtures and fresh temporal bones to evaluate implant mass, shape and orientation, attachment, electromagnetic coupling and acoustic properties. At both Hough Ear Institute and Symphonix Devices, Inc., we have shown that high fidelity and amplitudes can be recorded in vitro over a frequency range of 500 Hz to 10 kHz. These data can provide greater assurance of safety and efficacy to regulatory agencies before entering clinical trials. We propose that LDI be considered as an international standard for accurate, consistent comparison of performances of all IHDs during development. Furthermore, the future availability of human IHD data will allow for the extrapolation of a mechanical bench model of the middle ear transfer function for use in quality control during manufacturing and diagnosis of failure in IHDs.
Mechanical, Acoustic and Electromagnetic Evaluation of the Semi-Implantable Middle Ear Hearing Device (SIMEHD)
Authors: Abbass Hassan A. , Kane Michael , Garverick Steven , Ko Wen H. , Maniglia Anthony J. , Frenz William , Falk T. J.
Published: May 2019

The properties of the partially implantable middle ear hearing device (SIMEHD) were extensively studied. The internal unit was subjected to 5,000 cycles of bending at a force of 75 g (gravity) without failure. An accurate measurement of the force output of the SIMEHD was obtained (14 - 25 dynes/mA). This force is too small to cause any damage to the ossicular chain. The force resulting from electromagnetic interference over a wide frequency range (500 Khz - 1 Giga (109) Hz) was measured and noted to be within the margin of safety. The frequency response plots (500 - 8,000 Hz) were also obtained and revealed an excellent ability to amplify middle and high-frequency sounds.
Use of Magnetic Resonance Imaging and Magnetic Resonance Angiography in Diagnosis of Sigmoid Sinus Thrombosis
Authors: Davison Steven P. , Facer George W. , McGough Paul F. , McCaffrey Thomas V. , Reder Paul A.
Published: May 2019

Magnetic resonance angiography is an established radiologic technique which is rapidly becoming useful in imaging the head and neck. Currently, this imaging modality is important in the diagnosis of sigmoid sinus thrombosis caused by otologic disease. Since the introduction of antibiotic therapy, the percentage of deaths attributed to intracranial complications from otitic disease has decreased from 2.5 to approximately 0.25% of documented deaths. Also, the incidence of sinus thrombosis within this group has decreased, but it is still a serious and potentially lethal condition.

Sinus thrombosis is suspected clinically when mastoid disease progresses, with picket fence fever pattern, chills, headaches and signs of papilledema. Definitive diagnosis is necessary before surgical treatment. The Queckenstedt test is unreliable, computed tomography is better suited for demonstrating thrombosis of the sagittal sinus rather than the sigmoid sinus, and conventional angiography (although it provides excellent visualization) has the hazard of ionizing radiation and requires vessel puncture and the use of intraarterial contrast agents.

We present two cases of thrombosis of the sigmoid sinus as an intracranial otologic complication which were diagnosed definitively with magnetic resonance imaging and magnetic resonance angiography. The combination of magnetic resonance imaging, which showed the thrombosis displaying abnormal signal intensity, and magnetic resonance angiography, which demonstrated the absence of flow in the sinus, was an ideal diagnostic tool. For both patients, treatment consisted of mastoidectomy, sigmoid sinus decompression and antibiotics.
Wound Infection in Head and Neck Surgery: Implications for Perioperative Antibiotic Treatment
Authors: Weber Randal S.
Published: May 2019

Perioperative antibiotic treatment significantly reduces the risk of postoperative wound infection and is cost-effective in clean-contaminated head and neck operations. A clear consensus on the most suitable single agent or combination is, however, lacking. Most surgical wound infections involve both gram-positive and gram-negative aerobes and anaerobes; some organisms may exhibit antibiotic resistance through beta-lactamase production. Comparative trials have indicated that combinations with both aerobic and anaerobic activity provide protection superior to that achieved with single agents active against only aerobic pathogens. Recent results suggest that the beta-lactam/beta-lactamase-inhibitor combination ampi-cillin/sulbactam is cost-effective for perioperative treatment of patients undergoing head and neck surgery.