Jeffrey M. Ahn

Interleukin 1 Causing Bone Destruction in Middle Ear Cholesteatoma

We previously reported the localization of interleukin 1 in the epithelial layer of human cholesteatomas. On the basis of other studies that showed interleukin 1 can stimulate fibroblasts and macrophages to produce collagenases and prostaglandins, we then proposed that interleukin 1 may play an important role in cholesteatoma-related bone resorption, also. Our immunocytochemical study involving more human cholesteatoma samples revealed the presence of interleukin 1 in bone cells and monocytes in the region of active bone destruction. In the present study, the effect of interleukin 1 on these cells found at the bone resorption site was examined. By radioimmunoassay, interleukin 1 was shown to stimulate the production of prostaglandin E2 by osteoblasts in vitro. Interleukin 1 also promoted the migration and multinucleation of bone marrow-derived monocytes. These osteoclast-like cells formed from monocytes contained tartrate-resistant acid phosphatase, and caused the resorption of the devitalized bone in vitro. Above findings suggest that interleukin 1 could cause the bone destruction in cholesteatomas, not only by stimulating the local bone cells, but also by recruiting monocytes for osteoclastic bone resorption.

Localization of interleukin-1 in human cholesteatoma

Recent studies by other investigators have shown that interleukin-1 (IL-1) promotes bone resorption by stimulating various cells. Interleukin-1 not only stimulates collagenase production by fibroblasts and macrophages, but also acts as an osteoclast-activating factor. In this study, IL-1 was localized in human cholesteatoma tissues using both immunoperoxidase and immunofluorescent-staining methods with specific monoclonal antibodies. Highly concentrated IL-1 was found in the epithelial layer and granulation tissue. More specifically, intense staining was seen in basal and spinous cells of the epithelial layer, and in fibroblasts and macrophages of the granulation layer. We also located IL-1 in the normal external ear canal skin; however, the intensity of the staining in the cholesteatoma epithelium was found to be stronger. The presence of IL-1 in the epithelial layer and granulation tissue of the cholesteatoma suggests that IL-1 from the stimulated keratinocytes of the cholesteatoma could be one factor responsible for the markedly increased bone resorption observed in cholesteatoma patients.

Clinical Outcomes and Complications Associated with TORS for OSAHS: A Benchmark for Evaluating an Emerging Surgical Technology in a Targeted Application for Benign Disease

Background: The aim of this study was to create benchmarks for evaluating clinical outcomes and complications of transoral robotic surgeries (TORS) in a multicenter setting. Methods: 243 TORS for obstructive sleep apnea/hypopnea syndrome (OSAHS) operations, carried out between 2008 and 2012, were analyzed at 7 different centers. The average hospitalization was 3.5 days. The mean patient age was 50 ± 12 years, the average BMI at the time of the procedure was 28.53 ± 3.87 and the majority of the patients were men (81%). Results: The mean preoperative and postoperative apnea/hypopnea index was 43.0 ± 22.6 and 17.9 ± 18.4, respectively (p < 0.001). The mean preoperative and postoperative Epworth Sleepiness Scale score was 12.34 ± 5.19 and 5.7 ± 3.49, respectively (p < 0.001). The mean pre- and postoperative lowest O2 saturation was 79.5 ± 8.77 and 83.9 ± 6.38%, respectively (p < 0.001). Conclusions: Patients undergoing TORS as part of a multilevel approach for the treatment of OSAHS have a reasonable expectation of success with minimal long-term morbidity.

Transforming Growth Factor-α and Rhinitis

Objectives: Transforming growth factor‐α (TGF‐α) has been implicated in diverse physiologic and pathophysiologic functions including immunological, inflammatory, and neoplastic processes. TGF‐α has been localized in the hyperproliferative, inflammatory environment of chronic otitis media, cholesteatoma, and asthmatic airways. TGF‐β1, which must be present with TGF‐α to transform fibroblasts, has been found in rhinitic mucosa and in asthma in prior studies. The authors sought to identify whether TGF‐α also played a role in the inflammatory cascade and fibrosis of rhinitis. Study Design: A nonrandomized, prospective study was carried out in which samples of inferior turbinate and nasal polyps from rhinitic and nonrhinitic patients were subjected to immunohistochemistry and Western blotting to determine the presence of TGF‐α. Methods: Twenty‐seven subjects undergoing surgery for rhinitis, obstructive sleep apnea, nasal fracture, and rhinoplasty were recruited for this study, the latter three groups acting as controls. Immunohistochemical and Western blotting techniques were employed to identify the presence of TGF‐α in inferior‐turbinate and nasal‐polyp samples of rhinitic subjects. Results: Immunohistochemistry demonstrated the selective staining of TGF‐α in the basement membrane and extracellular matrix, including lymphatic, vascular, and glandular structures, in most turbinate samples and the absence of staining in corresponding controls. Further, TGF‐α was isolated to a discrete 30‐kD band in both inferior turbinate and polyp tissues by Western blotting without staining in the corresponding controls. Conclusions: These results suggest that TGF‐α may play a role in the inflammatory derangement of rhinitis.

Transoral Robotic Surgery (TORS) for the Management of Obstructive Sleep Apnea from Tongue Base Hypertrophy

Objectives: Obstructive sleep apnea (OSA) is a medical problem that afflicts millions of Americans with considerable sequelae. The base of tongue is recognized as a significant site of obstruction leading to hypopharyngeal collapse during sleep. Many existing procedures implemented for the management of OSA typically have restricted surgical access to the base of tongue. However, transoral robotic surgery (TORS) provides excellent exposure to the tongue base and lingual tonsils. We aim to assess the success of robotically assisted partial glossectomy for tongue base reduction in patients with OSA. Methods: Medical records of patients ages >18 who underwent TORS for surgical management of OSA from 2011 through 2012 were retrospectively reviewed. Pre-operative and post-operative polysomnography were performed, and the results were compared to assess for improvement in OSA. Results: Twenty-one patients completed the pre- and post-operative evaluations. The mean apnea hypopnea index (AHI) decreased from 37.0 pre-operatively to 14.9 post-operatively, with a mean AHI reduction of 22.1 (p = <0.01). The mean oxygen saturation nadir was 79.2% pre-operatively and 83.3% post-operatively, with a mean increase in oxygen saturation nadir of 4.1% (p = 0.04). Conclusions: TORS provides excellent surgical access to the tongue base, allowing for improved base of tongue reduction for the management of OSA. In our patients who underwent robotically assisted partial glossectomy for OSA, there was a significant reduction in AHI, as well as a significant increase in oxygen saturation nadir.