Faculty Bibliography

Nasal obstruction is known to be associated with a major decrease in disease-specific quality of life, and nasal valve dysfunction can play a considerable role in nasal airflow obstruction. Diagnosis and treatment of nasal valve dysfunction requires a thorough understanding of normal anatomy and function as well as pathophysiology of common abnormalities to properly treat the exact source of dysfunction. As the pathophysiology of the nasal valves has become better understood, surgery designed to treat its dysfunction has evolved. Here, we explore the progress we have made in treating the nasal valves, and the deficiencies we still face

OBJECTIVES: To gather data on, and assess the applicability of, intraoperative recurrent laryngeal nerve (RLN) monitoring during thyroidectomy and related cervical procedures in children and adolescents. Recurrent laryngeal nerve trauma is one of the most serious complications of surgery in the anterior neck compartment. Numerous studies have demonstrated the utility of intraoperative monitoring of the RLN in adult thyroid surgery to prevent such injury. Although the risk of RLN injury is reportedly higher in the pediatric population, little data exist regarding the use of intraoperative RLN monitoring in children and adolescents. DESIGN: Retrospective case series review. SETTING: A pediatric otolaryngology practice in a tertiary care hospital. PATIENTS: Five patients undergoing surgical excision of thyroid neoplasms or branchial pouch anomalies. INTERVENTIONS: During surgical excision, intraoperative RLN monitoring was performed with use of the Xomed NIM II monitor and Xomed RLN monitoring endotracheal tube, which allow for both passive and stimulation-evoked electromyographic monitoring of the thyroarytenoid muscle. MAIN OUTCOME MEASURES: True vocal fold mobility as assessed by postoperative flexible laryngoscopy. RESULTS: Intraoperative RLN monitoring was performed successfully for up to 4 hours. Such monitoring facilitated the identification of the RLN and was predictive of the subsequent presence or absence of postoperative RLN paresis. CONCLUSIONS: Intraoperative RLN monitoring can be a useful tool during cervical procedures that place the RLN at risk in children and adolescents. As has been demonstrated in adults, it is a safe and reliable technique that can be predictive of and may lessen the risk of RLN morbidity in this younger patient population

OBJECTIVE: Various energy delivery systems have been utilized to treat superficial rhytids in the aging face. The Intense Ultrasound System (IUS) is a novel modality capable of transcutaneously delivering controlled thermal energy at various depths while sparing the overlying tissues. The purpose of this feasibility study was to evaluate the response of porcine tissues to various IUS energy source conditions. Further evaluation was performed of the built-in imaging capabilities of the device. MATERIALS AND METHODS: Simulations were performed on ex vivo porcine tissues to estimate the thermal dose distribution in tissues after IUS exposures to determine the unique source settings that would produce thermal injury zones (TIZs) at given depths. Exposures were performed at escalating power settings and different exposure times (in the range of 1-7.6 J) using three IUS handpieces with unique frequencies and focal depths. Ultrasound imaging was performed before and after IUS exposures to detect changes in tissue consistency. Porcine tissues were examined using nitro-blue tetrazolium chloride (NBTC) staining sensitive for thermal lesions, both grossly and histologically. The dimensions and depth of the TIZs were measured from digital photographs and compared. RESULTS: IUS can reliably achieve discrete, TIZ at various depths within tissue without surface disruption. Changes in the TIZ dimensions and shape were observed as source settings were varied. As the source energy was increased, the thermal lesions became larger by growing proximally towards the tissue surface. Maximum lesion depth closely approximated the pre-set focal depth of a given handpiece. Ultrasound imaging detected well-demarcated TIZ at depths within the porcine muscle tissue. CONCLUSION: This study demonstrates the response of porcine tissue to various energy dose levels of Intense Ultrasound. Further study, especially on human facial tissue, is necessary in order to understand the utility of this modality in treating the aging face and potentially, other cosmetic applications

Spectrally-encoded miniature endoscopy uses a single optical fiber and wavelength division multiplexing to obtain macroscopic images through miniature, flexible probes. In turn, it has the potential to enable two- and three-dimensional imaging within the body at locations that are currently difficult to access with conventional endoscopes. Here we present a novel detection scheme for spectrally-encoded endoscopy using spectral-domain interferometry. Compared to previous time-domain configurations, this new detection method results in greater than 1000-fold increase in sensitivity (77 dB), a 6-fold increase in imaging speed (30 volumes per second), and a 2-fold increase in depth range (2.8 mm). We demonstrate spectrally-encoded, spectral-domain detection by conducting video-rate, three-dimensional imaging in a variety of specimens, including the paws of a mouse embryo and excised human ear bones. Our results show that this new technology enables video rate spectrally-encoded endoscopy and will therefore be useful for a variety of minimally invasive medical applications

OBJECTIVE: To evaluate the clinical safety of intense ultrasound in the treatment of the dermis and subcutaneous tissues of the face and neck in terms of skin inflammation, pain, adverse events, and histologic features. DESIGN: In an open-label, phase 1 study, patients scheduled to undergo a rhytidectomy were enrolled into immediate (face-lift surgery within 24 hours of intense ultrasound treatment) and delayed (face-lift surgery 4-12 weeks after treatment) treatment groups. Intense ultrasound treatments were performed as a series of several linear exposures delivered 1.5 to 2.0 mm apart with the use of 1 of 3 available handpieces with different focal depths. Subject pain ratings and standardized digital photographs were obtained at uniform points. Photographs were blindly rated for inflammation. Histologic evaluation of treated tissues was performed with nitroblue tetrazolium chloride viability stain. RESULTS: Fifteen subjects with a mean +/- SD age of 53 +/- 7 years were enrolled. Seven subjects were nonrandomly assigned to the immediate group and 8 were in the delayed group. On histologic examination, thermal injury zones were consistently identified in the dermis at exposure levels greater than 0.5 J as focal areas of denatured collagen. At this threshold level or above, most patient exposures were associated with transient superficial skin erythema and slight to mild discomfort on a standardized pain scale. No other adverse effects were noted in any case. Thermal injury zones were produced in the expected linear pattern and were consistent in size and depth from zone to zone. Increasing source power did not increase the depth of the epicenter of the thermal injury zone. Epidermis was spared in all cases. CONCLUSION: In this first clinical study of intense ultrasound therapy to facial tissues, the intense ultrasound system allowed for the safe and well-tolerated placement of targeted, precise, and consistent thermal injury zones in the dermis and subcutaneous tissues with sparing of the epidermis

OBJECTIVES: To transcutaneously deliver intense ultrasound (IUS) energy to target the facial superficial musculoaponeurotic system (SMAS), to produce discrete thermal injury zones (TIZs) in the SMAS, and to demonstrate the relative sparing of adjacent nontargeted layers superficial and deep to the SMAS layer. METHODS: In 6 unfixed human cadaveric specimens, the SMAS layer was visualized and targeted using the ultrasound imaging component of the IUS device. Using 2 IUS handpieces, 202 exposure lines were delivered bilaterally in multiple facial regions by varying combinations of power and exposure time (0.5-8.0 J). Tissue was then excised and examined grossly and histologically for evidence of thermal injury using nitroblue tetrazolium chloride viability stain. RESULTS: Reproducible TIZs were produced selectively in the SMAS at depths of up to 7.8 mm, and sparing of surrounding tissue including the epidermis. Higher energy settings and high-density exposure line pattern produced a greater degree of tissue shrinkage. CONCLUSIONS: In human cadaveric facial tissue, IUS can noninvasively target and selectively produce TIZs of reproducible location, size, and geometry in the SMAS layer. The ability to produce focused thermal collagen denaturation in the SMAS to induce shrinkage and tissue tightening has not been previously reported and has significant implications for aesthetic facial rejuvenation

Spectrally encoded confocal microscopy (SECM) is a technique that allows confocal microscopy to be performed through the confines of a narrow diameter optical fiber probe. We present a novel scheme for performing SECM in which a rapid wavelength swept source is used. The system allows large field of view images to be acquired at rates up to 30 frames/second. Images of resolution targets and tissue specimens acquired ex vivo demonstrate high lateral (1.4 mum) and axial (6 mum) resolution. Imaging of human skin was performed in vivo at depths of up to 350 mum, allowing cellular and sub-cellular details to be visualized in real time

BACKGROUND: Confocal reflectance microscopy (CRM) is an optical method of imaging tissue noninvasively without the need for fixation, sectioning, and staining as in standard histopathologic analysis. Image contrast is determined by natural differences in refractive indices of organelles and other subcellular structures within the tissues. Gray-scale images are displayed in real time on a video monitor and represent horizontal (en face) optical sections through the tissue. We hypothesized that CRM is capable of discerning histologic characteristics of different tissues in the head and neck. OBJECTIVES: To examine the microscopic anatomy of freshly excised head and neck surgical specimens en bloc using CRM and to compare the findings with those generated by conventional histologic analysis. DESIGN: This was a pilot observational cohort study. Bone, muscle, nerve, thyroid, parotid, and ethmoid mucosa from human surgical specimens were imaged immediately after excision. Confocal images were compared with corresponding routine paraffin-embedded, hematoxylin-eosin-stained sections obtained from the same tissue. RESULTS: Characteristic histologic features of various tissues and cell types were readily discernible by CRM and correlated well with permanent sections. However, in all tissues examined, there was less microscopic detail visible in the CRM images than was appreciated in paraffin-embedded histologic sections. CONCLUSIONS: The CRM images revealed cytologic features without the artifacts of histologic processing and thus may have the potential for use as an adjunct to frozen-section analysis in intraoperative consultation