Hyung Chae Yang

Vascular Leiomyoma in the Head and Neck Region: 11 Years Experience in One Institution

Objectives Vascular leiomyoma is an uncommon benign tumor of smooth muscle origin that arises from the muscularis layer of blood vessel walls. We report our experiences with the clinical manifestations, pathologic characteristics, and management of vascular leiomyoma in the head and neck. Methods The clinical records of 12 patients with vascular leiomyoma of the head and neck in the 11-year period were reviewed retrospectively. Results The 12 patients included nine men and three women. The locations of the tumors were variable, including nasal cavity, auricle, hard palate, upper lip, upper eyelid, and supraclavicular space. All but three patients reported an asymptomatic spherical mass; the other three patients complained of intermittent epistaxis or unilateral nasal obstruction resulting from the tumor originating in the nasal cavity. All tumors were painless. Computed tomography consistently revealed a well-defined, intensely enhanced small mass on the mucosa. No case was dignosed corretly as vascular leiomyoma before surgical excision. All patients underwent localized surgical excision of the tumor without recurrence. Five of 12 tumors (42%) were of solid type, four (33%) were of venous type, and three (25%) were of cavernous in histological classification. The histologic type was not related to gender, site of occurrence, and presence of pain. Conclusion Vascular leiomyoma presents as a small, painless mass in various locations of the head and neck region. Localized surgical excision is the only way to make the diagnosis and yields excellent results.

Generation of electrical power under human skin by subdermal solar cell arrays for implantable bioelectronic devices

Medical electronic implants can significantly improve peoples health and quality of life. These implants are typically powered by batteries, which usually have a finite lifetime and therefore must be replaced periodically using surgical procedures. Recently, subdermal solar cells that can generate electricity by absorbing light transmitted through skin have been proposed as a sustainable electricity source to power medical electronic implants in bodies. However, the results to date have been obtained with animal models. To apply the technology to human beings, electrical performance should be characterized using human skin covering the subdermal solar cells. In this paper, we present electrical performance results (up to 9.05mW/cm2) of the implantable solar cell array under 59 human skin samples isolated from 10 cadavers. The results indicate that the power densities depend on the thickness and tone of the human skin, e.g., higher power was generated under thinner and brighter skin. The generated power density is high enough to operate currently available medical electronic implants such as pacemakers that require tens of microwatt.

Effect of piperacillin-tazobactam coated β-tricalcium phosphate for mastoid obliteration in otitis media

BACKGROUND AND OBJECTIVE β-Tricalcium phosphate (TCP) has good biodegradability and osteoconductivity as a scaffold material for bone tissue engineering. Both block and granular forms are available; however, it has been associated with risk of infection and exposure. To this end, the study evaluated the effect of piperacillin-tazobactam coated β-TCPs for mastoid obliteration in otitis media. MATERIALS AND METHODS Ten guinea pigs were divided into the experimental (piperacillin-tazobactam coated β-TCP granules, n=5) and control groups (uncoated β-TCP granules, n=5). After mastoid obliteration, transtympanic injection with a saline suspension of lipopolysaccharide established inflammation. The animals were sacrificed 5 weeks later. Tissue sections were stained with hematoxylin and eosin and examined. RESULTS Encapsulation and formation of fibrous capsule by foreign material in the bulla were not evident. The histological evaluation did not reveal inflammatory cells and fibrosis in the piperacillin-tazobactam coated β-TCP group. In contrast, the control group showed numerous inflammatory cells around the implanted uncoated β-TCP granules and incomplete new bone formation. CONCLUSION β-TCP is an effective carrier material for piperacillin-tazobactam. The use of piperacillin-tazobactam coated β-TCP may be optimal for mastoid obliteration.

Efficacy of Concomitant Intratympanic Steroid Injection for Sudden Deafness According to Initial Hearing Loss.

Objectives/Hypothesis: We identified the efficacy and appropriate target group for intratympanic steroid injections (ITS) in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). Study Design: Retrospective case-control study. Methods: Fifty-five ears treated with concomitant ITS and systemic steroids and 165 ears without ITS treatment were identified. Each case had three controls matched according to the age, sex, and the presence of vertigo. Patients were divided into subgroups according to pure tone audiometric configuration and the levels of initial hearing loss. Hearing results and frequency-related hearing gain were investigated. Results: Additional ITS was effective for patients with an ascending type audiogram or patients with Grade 3 (60–90 dB) initial hearing loss. Concomitant ITS, however, resulted in a negative effect on hearing in patients with Grades 1 and 2 (<60 dB). ITS resulted in significant (p < 0.05) hearing improvement at 250 Hz in the Grade 3 (60–90 dB) and Grade 4 (>90 dB) ITS subgroups. Conclusions: The efficacy of additional ITS for ISSNHL was different among subgroups with various levels of initial hearing loss or audiogram configuration.

Donor-Site Morbidity Following Minimally Invasive Costal Cartilage Harvest Technique

Objectives Autologous costal cartilage is a promising alternative for mastoid obliteration. However, donor-site morbidities of the chest wall limit the use of this graft. To address this issue, we have developed a minimally-invasive technique of harvesting costal cartilage and report donor site morbidity associated with the procedure. Methods Donor site morbidities were evaluated for 151 patients who underwent costal cartilage harvest, canal wall down mastoidectomy, and mastoid obliteration. Pain and cosmetic concern were evaluated via visual analogue scale (VAS). Scars were evaluated via the modified Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). Postoperative complications were assessed during the follow-up period. Results The mean duration of noticeable pain was 5.3 days post operation. The mean VAS score for pain was 3.0 of 10 on the first day after the operation and gradually declined. At the 6 months post operation, the mean VAS cosmetic score at the costal cartilage harvest site was 0.6 of 10. The mean VSS score was 9.5 out of 10 total, and the mean POSAS score was 23.27 out of 110 total. Conclusion The minimally-invasive chopped costal cartilage harvest technique resulted in acceptable pain, cosmetic concern, and postoperative complications for most patients. There were no major postoperative complications. Costal cartilage is an acceptable donor for mastoid obliteration in canal wall down mastoidectomy, especially in the context of the extremely low donor site morbidity of the minimally-invasive technique presented in the study.

Efficacy of tympanoplasty without mastoidectomy on MRSA-infected chronic otitis media.

Objectives/Hypothesis The prevalence of methicillin-resistant Staphylococcus aureus (MRSA)-infected chronic otitis media (COM) has been increasing, but to date, there has been no consensus on surgical treatment. Although there is a report that mastoidectomy is essential in treating MRSA-infected COM, in our experience, we found that tympanoplasty without mastoidectomy was sufficient. In this study, we evaluated the efficacy of tympanoplasty without mastoidectomy on MRSA-infected COM. Study Design Retrospective case-control study. Methods Forty ears with MRSA-infected COM that underwent tympanoplasty without mastoidectomy were identified at a tertiary referral center from February 2006 to September 2011. Each case had two controls matched. Hearing results and postoperative complication were examined to evaluate the efficacy of tympanoplasty. The preoperative and postoperative pure tone audiometry was checked. Results In the MRSA group and control group, 5 out of 40 ears (12.5%) and 8 out of 80 ears (10%) showed postoperative complications, respectively. The hearing success rate was 95.8% (23/24) in the MRSA group and 91.7% (44/48) in the control group. In the MRSA group, the average air-bone gap was 20 dB preoperatively, and it improved to 14 dB postoperatively. In the control group, the average air-bone gap was 19 dB preoperatively, and it improved to 13 dB postoperatively. There was no statistically significant difference between the MRSA and control groups. Conclusions Tympanoplasty without mastoidectomy showed efficacy in MRSA-infected COM.

Effect of Ginkgo biloba extract on endotoxin-induced labyrinthitis

OBJECTIVE There are no reports on the therapeutic effect of Ginkgo biloba extract (GBE) on otitis media-induced labyrinthitis. The present study examined whether GBE can protect against cochlear damage induced by intratympanic instillation of lipopolysaccharide (LPS)-induced labyrinthitis. MATERIALS AND METHODS Experiments were performed in 20 healthy young male guinea pigs. The control group (n=10) received an intratympanic instillation of LPS (20 μl, 3mg/ml). The experimental group (n=10) received intratympanic instillation of LPS immediately after instillation of GBE (10mg/kg) and then experimental groups received GBE (100mg/kg) by intraperitoneal injection every day for 3 days. Instillation of LPS or LPS immediately after GBE was done in the right ear; the untreated left ear was considered normal. Physiological and morphological changes were evaluated. RESULTS Statistical analysis of treatment of GBE revealed significantly less hearing loss than LPS group (p<0.05). The ratio of the value of cochlear blood flow (CBF) compared to untreated left side was significantly higher in the GBE treated group than in the LPS-treated group (p<0.05). This result indicated the recovery of CBF in GBE treated group compared to LPS treated group. In the LPS group, scanning electron microscopy revealed hair cell damage with edema. Missing stereocilia in the third layer of the outer hair cell was revealed. However, both the inner hair cells and the outer hair cells had normal appearance in the GBE group. LPS group showed that cochlear Evans blue extravasation was increased strongly in the stria vascularis, spiral limbus, and in the spiral ligament compared with the GBE treated group. CONCLUSION GBE significantly minimizes cochlear damage against LPS-induced otitis media with labyrinthitis in a guinea pig model. GBE has potential as an adjunctive therapy to antibiotics in the treatment of acute otitis media with complicated labyrinthitis.

Effectiveness of anatomic criteria for predicting parotid tumour location.

We evaluated the accuracy, positive predictive value (PPV), negative predictive value (NPV), specificity and sensitivity of eight anatomic landmarks to differentiate parotid deep lobe tumours from superficial lobe tumours: the lateral margin of the retromandibular vein (RMV), a straight line from the facial nerve trunk (FN trunk) to the mandibular ramus (FN line), a straight line from the FN trunk to the RMV (tRMV), a straight line from the FN trunk to the lateral margin of the masseter (tMasseter), a straight line from the ipsilateral vertebral posterior end to the RMV (U‐line), an arc with a radius of 8.5 mm centred on the mandibular ramus (Conns arc), a straight line from the lateral surface of the masseter muscle to the lateral margin of the RMV (rMasseter) and an angle from the FN line, tumour and the lateral margin of the masseter muscle (FTM angle).

Newborn hearing screening in prematurity: fate of screening failures and auditory maturation

The purpose of this study was to identify delayed auditory maturation and the fate of premature infants who failed the newborn hearing screening (NHS) in neonatal intensive care unit.

Transnasal endoscopic removal of bilateral postoperative maxillary cysts after aesthetic orthognathic ssurgery: Differences from that of Caldwell-Luc operations

Postoperative maxillary cysts (PMCs) after orthognathic surgery are a rare disease condition. In this study, we reported first case of bilateral PMCs after cosmetic orthognathic surgery which was treated via the intranasal endoscopic approach. In addition, we compared the characteristics of PMCs after aesthetic orthognathic surgery with those of PMCs after Caldwell-Luc operation. We expect that this case will be helpful to surgeons who encounter similar cases.