The developmental and subsequent addition of laser technology to existing surgical techniques offered new and exciting Possibilities for improving traditional endoscopic operations and expanding the scope of the specialty of otolaryngology-head and neck surgery. Lasers were found to be Precise, but potentially dangerous, surgical instruments whose use was associated with certain distinct and unprecedented advantages, but also with many unique and potentially serious, and sometimes catastrophic complications. The Purpose of this study was to evaluate the of elation technique of $CO_2$laser, kinds of anesthesia, equipments of operating room, and education of medical staff. Four hundreds 4 cases of $CO_2$laser laryngeal microsurgery were reviewed for the safety of $CO_2$laser in laryngeal microsurgery. Vocal polyp (46,3%) was the most common pathology in our cases. The others were vocal nodule, Reinke`s edema, epiglottic cyst, laryngeal granuloma, laryngeal papilloma, intracordal cysts, laryngeal tuberculosis, laryngeal web, laryngotracheal stenosis, and laryngeal cancer. Following complete equipment controls, treatment area controls, maintenance, service and procedural controls, personel protective equipment, and warning signs, no complications were found in our cases. In conclusion, laryngeal microsurgery with $CO_2$laser could be done safely without complication if complete preoperative preparation and education of medical staff preceded.

Background and Objectives : Decannulation failure may result from factors such as inadequate ability 0 clear secretion, mucosal induration, granulation tissue, restenosis, tracheal wall depression and vocal cord palsy. We were to evaluate the effectiveness of surgical treatment on the basis of site and type of stenosis. Materials and Method : A series of 44 cases of decannulation difficulty between 1993 and 1997 were reviewed. The following data were collected on each of these patients : primary disease, indication for tracheostomy, site of stenosis, endoscopic findings of stenosis, surgical techniques used for treatment. Results : Primary diseases were 30 head trauma, 4 neck injury, 10 other diseases. Indication for tracheostomy were 37 prolonged intubation, 4 emergency tracheostomy, 3 laryngeal trauma. Endoscopic findings of stenosis were 24 granulation tissue, 16 laryngotracheal collapse, 4 combined with granulation tissue and collapse. Site of stenosis were 3 glottic, 9 subglottic, 24 stomal, 1 substomal, 7 mixed. 22 of 24 cases were decannulation using endoscopic treatment. Conclusion : The most common cause of failed decannulation was sternal granulation tissue. The most effective treatment of granulation tissue was endoscopic technique.

Postoperative pain following tonsillectomy remains a significant obstacle to speedy recovery and smooth convalescence. Inadequate analgesia causes poor oral intake and influences the length of hospital stay and ability to return to normal activity. Patient Controlled Analgesia (PCA) is a method of analgesia adminstration that consists of a computer driven pump with a button that the patient may press to adminster a small dose of analgesic drug. The aim of this study was to examine whether Intravenous Patient Controlled Analgesia (IV-PCA) can reduce postoperative pain after tonsillectomy. The 100 patients undergoing tonsillectomy with general anesthesia were divided into two groups. The PCA group patients (n=80) received a mixture of nalbuphine and ketorolac by Walkmed PCA infusor during first 48 postoperative hours. In control group (n=20), the patients received oral acetoaminophen (Tyrenol) regularly and tiaprofenic acid (Surgam) intramuscularly on a p.r.n basis. Analgesic efficacy was evaluated with visual linear analogue scale (VAS) and the adverse effects were evaluated with 4 point scale. The patients of PCA group had less pain than those of control group. The adverse effects in the PCA group were nausea and vomiting. This study suggests that IV-PCA may be safe and effective method of pain control after adult tonsillectomy and is better accepted than oral or intramuscular pain medications.

Provox is now widely used for voice rehabilitation for total laryngectomized patient because of its low airway resistance and easiness for phonation. This study was designed to reveal the influence of radiation therapy on Proven complications. Forty-four patients who underwent total laryngectomy were grouped into group A (no radiation), group B(radiation and then Provox insertion), group C(Proven insertion and then radiation). Provox complications were leakage, granulation tissue formation, malfunction and infection. The average survival time of Provox was longer in group C (9.2 me) than group A(8.6 m) or group B (7.3 me), but no statistical significance was found. The first time of Provox change was 10.2, 8.6 and 9.7 months respectively. The incidence of complication was not significantly different among groups. The cases of Provox remeval due to shunt failure were 5, 4 and 2 respectively. Even though a significant statistically difference was not found partialy due to the small numbers of patients, a special caution should be exercised in inserting Provox to prevent a serious complication for the patients who had a history of previous radiation.

Platelet activating factor (PAP) has been known as implicating as one of potent inflammatory mediators and reported 0 be involved in inflammation and allergy. PAF induces ciliary dysfunction and epithelial damage of human paranasal sinus mucosa in vitro. However, several recent papers have reported that PAF may not readily damage the airway epithelium. The aim of this study was to investigate the ultrastructural evidence to elucidate the pathogenesis of epithelial damage induced by PAF. Sixteen $\mu\textrm{g}$ g of PAF was applied into the maxillary sinuses of 6 rabbits. Rabbits were divided into 2 subgroups along with time interval at 1st and 3rd experimental day, and sinus mucosae were taken for the histopathologic study using electron microscopy. At 1st day, epithelial cells showed no ultrastructural change. Ultrastructures of the cilia were well preserved. Subepithelial space showed no evidence of the infiltration of inflammatory cells. Intravascular platelet aggregation and swelling of endothelial cells were evident. At 3rd day, epithelial cells showed vacuolar degeneration. Fusion of cilia forming giant cilia and focal loss of cilia were evident. Eosinophils were infiltrated in subepithelial and intraepithelial space. Swelling of endothelial cells, and migration of inflammatory cells into the connective tissue were evident. This study implies that epithelial damage induced by PAF may be secondary to the cytotoxicity of mobilized eosinophils rather than direct cytotoxicity of PAF.

Background and Objectives： The most common cause of the failure of endoscopic dacryocystorhinostomy is closure of the osteotomy site due to granulation or adhesion. We used mitomycin-C, an antineoplastic antibiotic agent, soaking over the osteotomy site to suppress fibrous proliferation and scar formation during the endoscopic dacryocystorhinostomy. Materials and Methods : A total of 20 Patients diagnosed with nasolacrimal duct obstruction were assigned randomly to either a mitomycin-C group or a control group. Endoscopic dacryocystochinostnmy has been used in both groups. In the mitomycin-C group, a piece of merocel soaked with 0.2 mg/ml mitomycin-C was applied to the osteotomy site and then after 30 minutes was removed. Results : All patients in the mitomycin-C group remained symptom free after removal of their silicone tube (100% success), and there were two patients in the control group who had recurrent epiphora (67% success). In the mitomycin-C group, the average surface area of the osteotomy at the end of the sixth postoperative month was 4.1 $\textrm{mm}^2$, whereas that of the control group was 2.5 $\textrm{mm}^2$. Neither serious systemic nor local toxicity were noted in the mitomycin-C group. Conclusion : Intraoperative mitomycin-C may possibly improve success rates over the endoscopic dacryocystorhinostomy procedure.

Gastroesophageal reflux (GER) has been considered one of major causes in patient with globus symptom. Diagnostic methods for GER are gastroesophagoscopy, acid perfusion test esophagogram, esophageal manometry, 24-hour double probe pH-metry, and so on. According to the literature, positive rate of GER on esophagogram was reported variably from 4.7% to 45.9% and the outcome of classical treatment with antacid and prokinetic agent was reported from 70% to 84%. We reviewed the medical records of 81 patients with globus symptom. Each patient had been performed esophagogram and treated with antacid and prokinetic agent. Positive rate of GER on esophagogram was 46.9%. Complete resolution and improvement of globus symptom was 79% overally, 92% in positive group of GER rut esophgogram, and 72% in negative group. Considering aspects of time-cost and compliance of patient esophagogram is one of the screening methods of GER in patients with globus symptom. Antacid and prokinetic agent is recommended in treatment of patients with globus symptom.

Human papillomavirus(HPV) is epitheliotrophic virus invading the anogenital tract and the upper aerodigestive tract HRV produces a diversity of benign and maljgnant tumors. In this study, the author determined the frequency of association of human papillomavirus(HPV) and laryngeal carcinomas and investigated the significance of HRV infection of different subtypes in the tumorigenesis of laryngeal carcinoma. Laryngeal squamous cell cancinomas from 34 patients who did not have preexisting papillomas by clinical history were retrieved from formalin-fixed, paraffin-embedded blocks and analyzed for HPV. Nineteen cases were tumors of the true vocal folds, 11 were supraglottic and 4 were transglottic. HPV detection was dane using polymerase chain reaction amplification with HPV L$_1$consensus primer. HPV type was determined by the same method using HPV-6, 11 and 16,-18 type-specific E6 primers. The results were as follows : 1) HPV DNA was detected in 7 cases among the 34 patients(20.6%). According to the type of HPV DNA HPV-11 was detected in 3 cases, HPV-16 was detected in 2 cases and HPV-6 and HPV-18 were detected in 1 case, respectively. 2) These 7 HPV-positive patients were advanced cancinoma cases. From these results, we concluded that HPV was thought to be the etiological factor of laryngeal squamous cell carcinomas.

Benign salivary gland tumors have relatively lower incidence, but it have various histopathologic diagnosis and biological behavior. Authors analyzed retrospectively 77 patients with benign salivary gland tumor who were treated surgically and had the following results. The most frequent age group was 5th decade, and sex distribution was not specific. The most common location was parotid gland(75.3%) and submandibular gland(20.8%) was next. Histopathologically, the most common salivary gland tumor was pleomorphic adenoma(82.7%) and Warthin's tumor(8.6%) was next. An asymptomatic mass was the most common presentation. Duration of symptoms and signs were mostly under the 5years(90.9%). Diameter of tumors was mostly under 4cm(76.7%). Parotid gland tumors were treated mostly with superficial parotidectomy and submandibular gland tumors were treated mostly with submandibular gland resection. The most common complication was facial nerve palsy(9 cases).

There have been few large scale surveys of salivary gland tumors, because the salivary gland tumors comprised less than 3 percent of all neoplasms of the head and neck. Also there is a problem that the incidences of specific types of tumors have the variation according to the geographic regions. ]'nother Korean reports about salivary gland tumor, they only treated about 100 cases only. Objectives : The purpose of this study is to identify the frequency and clinical characteristics of salivary gland tumors and to compare with other Korean reports. Materials and Methods : We had performed to analyze 387 cases of salivary gland tumors from 1983 to June 1997, were reviewed in histopathological and clinical aspects. The diagnoses of individual tumors were based on the World Health Organization classification. Tumors were analyzed according to the histologic type site, age and sex. Results : The majority (79.1%) of cases occurred in the major salivary glands and 20.9% in the minor. The parotid gland was the most frequent site with 52.4％ and submandibular glands with 26.3%. Benign tumors were 79.3% of the tumors and malignant tmon were 20.7%. The most frequent tumor was pleomorphic adenoma occupied 63.8% of the total and frequency percent of histologic type of 98 malignant tumors showed 35.7% of mucoepidermoid carcinomas, 24.5% of adenoid cystic carcinomas. Overall gender with female predominance with 1 : 1.4 of male to female ratio. The average age of patients was 42.8 years. The most frequent chief complaint was a palpable mass. The duration of the symptom was shorter in the malignant salivary gland tumors (26.7 months) than in the benign salivary gland tumors (38.2 months). Conclusion : Comparing to the previous Korean reports, the present study confirms that the incidence of salivary gland tumor was lower in the parotid gland, and was higher in the submandibular and minor salivary glands.

Bilateral vocal cord paralysis can result in severe airway compromise. Over the years a variety of arytenoidectomy procedures have bee described, and one or more of these have been the gold standard for many years. A widely accepted treatment is endoscopic laser total arytenoidectomy. However, vocal results are usually poor. Objective : To evaluate the effect of treatment of endoscopic laser medial partial arytenoidectorny for bilateral vocal cord paralysis Material and Methods : We performed endoscopic medial partial arytenoidceomy with $CO_2$laser for 3 patients with bilateral vocal cord paralysis. The $CO_2$laser is operated with a continuous 7-watt beam in superpulse mode. We compared degree of dyspnea and glottic area of pre-operation with those of post-operation for 3 patients. We analysed aerodynamic study pre-operatively and post-operatively for 1 patient. Results The symptom of dyspnea was improved markedly and the glottic area was widened from 34% to 50% compared with that of pre-operation. The voice quality was slightly decreased. Tracheotomy was not necessary for not-tracheotomized patient and decanulation was possible for tracheotomized patient post-operatively. Cunclusion： The endoscopic laser medial partial arytenoidectomy is a convient and effective method for opening the posterior glottic airway.

폐에 발생하는 점액표피양 암종은 기관 및 기관지 점막하선에서 발생하는 드문 악성종양이다. 저자들은 좌측 주기관지와 우측중간 기관지에 발생한 점액표피양 암종을 각각 수상절제술 및 폐엽절제술로 치료하였다. 수술 후 별 합병증 없이 각각 3년, 18개월간 추적관찰중이다.

Esophageal perforation is uncommon, however, due to the lack of serosa layer inflammation spread is rapid and common to neighboring structures, leading to significant mortality and morbidity. With an advancement of endoscopic diagnosis there is an increase of esophageal injury and perforation due to esophageal endoscopic procedure. The authors have recently experienced three cases of iatrogenic esophageal perforation following diagnostic endoscopic procedure of the esophagus. We summarize the pervention, diagnostic and therapeutic strategies for iatrogenic perforation.

Warfarin sodium is a widely used oral anticoagulant and it sometimes causes hemorrhage in various sites such as traumatic or operative wounds, urologic organs, gastrointesitnal tract and subcutaneous tissues. Warfarin induced hemorrhage in upper respiratory tract causing upper airway obstruction is extremely rare. Despite the life-threatening nature of this complication, the symptoms are obscure like sore throat or hoarseness, suggesting infection and early diagnosis can be delayed. Careful medical history is emphasized When bleeding is observed, the patient should be admitted for close observation and prompt treatment. Recently we have exrperienced a case of laryngeal and upper tracheal submucosal hemorrhage induced by long term warfarin in 64 years old mm. We described the case with a review of the literature.

Subcutaneous emphysema is an unusual and rarely reported complication of tonsillectomy. The more commen complications are hemorrhage, infection and following anesthesia, aspiration, cardiac arrhythmia, and laryngeal trauma can occur. Posttonsillectomy subcutaneous emphysema results directly from the introduction of air into the tonsillar bed either during the surgical procedure itself or in the postoperative period. This condition is generally benign and self limiting and usually requires treatment only for the primary respiratory disease. In this report, we describe a 40-year-old female patient in whom subcutaneous emphysema developed shortly after tonsillectomy. She was observed for 5 days, at which point subcutaneous emphysema was seen on the follow up soft tissue neck X-ray to disappeared.

Osteomas are uncommon benign turners, occasionally located in the paranasal sinuses, of which the frontal and ethmoid sinus is the most frequent site. The etiology of the osteoma is still unknown but three possible theories have been proposed; embryological, traumatic and infective. The most common symptoms of osteoma are facial pain and headache, but most of them are asymptomatic and discovered incidentally on routine sinus radiography. Recently, the authors experienced two cases of large osteoma of the ethmoid sinus that were removed successfully by external ethmoidectomy.

Chondrosarcoma of bone commonly involve the pelvis, femur and shoulder girdle but the hyoid bone is a rare site for primary chondrosarcoma with approximately 10 cases having been reported in the literature. Radiologically it was well marginated and radiolucent mass with medullary bone destruction and central calcification. Wide surgical excision with or without radiotherapy is genera31y regarded as the treatment of choice for chondrosarcoma. Histopathology of chondrosarcoma was classified to clear cell chondrosarcoma, mucinous chondrosarcoma, dedifferentiated chondrosarcoma, and mesenchymal chondrosarcoma. We report a case of chondrosarcoma that originated from the right greater cornu of the hyoid bone, which underwent excision of the tumor with hemihyoidectomy and postoperative radiotherapy was performed.

Esophageal foreign body are not uncommon problems in the otolaryngologic field. Esophageal foreign body may cause severe complications such as esophageal ulceration, esophageal perforation, periesophagitis, tracheo-esophageal fistula, mediastinitis, pneumothorax pyothorax according to the kinds, shape, size, duration of lodgement of foreign body. The majority of esophageal foreign U which lodge in the esophagus can be removed endoscopically, but the following type of foreign body may require removal by external route. 1. an impacted foreign body 2. a foreign body producing esophagitis after unsuccessful attempts at removal through the esopahgoscope 3. a periesophageal abscess with a foreign body lodging in the abscess itself. Recently, we experienced a case of esophageal foreign body (fish bone) which penetrate the cervical esophageal wall and formed retropharyngeal abscess in 54-year old female. The foreign body are successfully removed and abscess was drained by external route through the lat neck.

Most laryngeal carcinomas are squamous cell carcinomas. Adenocarcinoma of the larynx is rare, its incidence has been reported less than 1% of all laryngeal neoplasms. Adenocarcinoma arises from glandular structures of the larynx and usually arises from the supraglottis. Compared to other carcinoma, deep biopsy and aggressive treatment is manditory. We report a case of adenocarcinoma of the larynx with review of current literatures.