악하선에 발생한 고대 신경초종 1예

여창기 대한이비인후과학회 2008 대한이비인후과학회지 두경부외과학 Vol.51 No.8

Ancient schwannoma is a benign neoplasm of nerve origin and may cause difficulties in the differential diagnosis with other benign or malignant tumors. It is also a rare variant of schwannoma with atypical tumor cells with nuclear pleomorphism and hyperchromatism. In this report, a 44-years-old female patient with an ancient schwannoma of the submandibular gland is presented, discussed, and the literature is reviewed for head and neck location of this tumor. (Korean J Otorhinolaryngol-Head Neck Surg 2008;51:758-60)

The Effectiveness of Subdural Drains Using Urokinase after Burr Hole Evacuation of Subacute Subdural Hematoma in Elderly Patients : A Prelimilary Report

여창기,전우열,김성호,김오룡,김민수 대한신경손상학회 2016 Korean Journal of Neurotrauma Vol.12 No.2

Objective: A subdural drain using urokinase after a burr hole hematoma evacuation was performed for subacute subdural hematoma (SASDH), and its effectiveness and safety in elderly patients were evaluated. Methods: Between January 2013 and May 2015, subdural drains using urokinase after burr hole hematoma evacuation were performed in 19 elderly patients. The inclusion criteria were as follows: 1) a subdural hematoma occurring between 4 and 20 days after injury; 2) worsening neurological symptoms, from mild to moderate or severe, due to injury during the subacute stage; 3) a mix of solid clots (high-density lighter shadow) and fluid hematoma (low-density darker shadow) on the computed tomography (CT) scan; 4) a score of ≥9 on the Glasgow Coma Scale (GCS) assessed immediately before surgery; and 5) an age of ≥65 years. When the majority of the hematoma was evacuated on the CT, we removed the catheter. Results: Under local anesthesia, a catheter was inserted into the hematoma through a burr hole. The mean age of the patients was 73.7 years (range, 65-87 years). The mean preoperative GCS score was 11.2 (range, 10-13), and the mean Glasgow Outcome Scale score for all patients was 5 at discharge. No recurrences of hematomas or surgical complications were observed. Conclusion: A subdural drain using urokinase after burr hole hematoma evacuation under local anesthesia is thought to be an effective and safe method of blood clot removal with low morbidity. This surgical method is less invasive for treating elderly patients with SASDH.

Three-Years Outcome of Microdiscectomy via Paramedian Approach for Lumbar Foraminal or Extraforaminal Disc Herniations in Elderly Patients over 65 Years Old

여창기,전익찬,김상우,고삼규,우병길,송광철 대한척추신경외과학회 2016 Neurospine Vol.13 No.3

Objective: Lumbar foraminal or extraforaminal disc herniations (FEFDH) have unusual clinical features and higher incidence in elderly patients compared to usual intraspinal canal disc herniations. We evaluated the efficacy of microdiscectomy via paramedian approach for lumbar FEFDH in elderly patients over the age of 65. Methods: Retrospective study was performed in 68 patients over the age of 65 (23 male and 45 female patients; 71.46±3.87 years) who underwent microdiscectomy via paramedian approach for unilateral lumbar FEFDH causing sciatica. The radiological factors including degree of slippage, presence of instability, disc height, and degree of disc degeneration; pain and functional status by the means of visual analogue scale score, Oswestry Disability Index score, and Macnab classification were analyzed preoperatively and during the postoperative follow-up period of 3 years to evaluate the efficacy of the surgical treatment. Results: Pain and functional status improved according to short- and long-term follow-up evaluations after surgery. Radiological changes following surgery, which can be understood as structural deteriorations and deformations, did not represent patient condition. Nine patients underwent additional surgery due to sustained or recurring leg pain of aggravation of back pain, and fusion surgery was required for 3 patients. Degree of preoperative slippage was the only statistically significant factor related to additional surgery (p<0.05). Conclusion: Microdiscectomy via paramedian approach for FEFDH may be a good surgical alternative in elderly patients. Radiological changes after surgery did not show a concordance with patients’ actual functional status. The excessive preoperative slippage tended to lead to unfavorable result after surgery and was associated with additional surgery.

접촉점의 마찰을 고려한 OHC 형 캠-밸브기구의 본드그래프 모델과 캠축 토크해석

여창기,이인환,김현수 한국자동차공학회 1991 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

최근 엔진의 경량화, 고속화가 이루어짐에 따라 캠-밸브기구의 동특성에 관한 연구는 엔진 설계에 있어서 중요한 부분을 차지하게 되었다. 캠-밸브 기구의 동특성에 대하여는 주로 캠-밸브기구의 분리현상(jumping & bouncing), 밸브 스프링의 서어지(surge)현상과 캠-밸브기구 각 접촉점의 접촉력 등에 관한 연구가 국내외에서 이루어져왔다. 그러나 캠축의 피로파괴, 타이밍벨트를 포함한 동력전달시스템의 성능과 수명에 치명적인 영향을 주며, 캠축 비틀림진동의 원인이 되는 캠축의 토크변동에 대한 연구는 거의 이루어지지 않고 있는 실정이다. <br/> pisano[1]는 캠과 종동자가구에 대한 기존연구[2-4]를 바탕으로 OHC 형 캠-밸브기구를 이론적으로 해석 하였다. pisano는 밸브 스프링을 하나의 스프링과 댐퍼로 보고 밸브의 상하 및 평면 회전운동을 고려하여 6 자유도로 모형화 하였다. 김 원진[5]은 캠-밸브기구에서 밸브의 상하운동만 고려하고 밸브 스프링을 2 자유도로 모형화 하여 서어지현상을 고려한 OHC 형 캠-밸브기구의 동특성 해석을 하였다. 김 정우[6]는 타이밍 벨트를 포함한 캠 구동계의 비틀림 진동현상을 해석하기 위하여 기존의 캠-밸브기구 모델[5]을 이용하여 캠축 토크를 계산하였다. 이상의 기존 연구들은 각 접촉점에서 발생하는 마찰력의 영향을 캠-밸브기구의 모형화에 전혀 포함시키지 않았다.<br/> 본 연구에서는 OHC 형 캠-밸브 기구를 본드그래프 모델링기법(Bondgraph Modeling Method)으로 모형화하고 각 접촉점들의 마찰을 고려한 캠축 토크를 수치해석으로 구하여 OHC 형 캠-밸브기구 및 타이밍벨트 구동시스템 설계의 기초자료를 얻고자 한다.

갑상선 양성결절의 고주파 치료

여창기 대한이비인후과학회 2014 대한이비인후과학회지 두경부외과학 Vol.57 No.3

Radiofrequency ablation (RFA) is not only a procedure used in treating malignant liver tumors, but is also a valuable way of treating benign thyroid nodules. RFA can be used in almost every patient, regardless of the contents of the solid component. One of the merits of RFA is that it may be used as an alternative to benign thyroid nodule surgeries. With this method, patients who so only choice in the past were to get surgeries can be treated in another way. This article reviews the indications, pre-procedural evaluations, techniques, results, and complications of thyroid radiofrequency ablation. Korean J Otorhinolaryngol-Head Neck Surg 2014;57(3):151-4

Delayed or Missed Diagnosis of Cervical Instability after Traumatic Injury: Usefulness of Dynamic Flexion and Extension Radiographs

여창기,전익찬,김상우 대한척추신경외과학회 2015 Neurospine Vol.12 No.3

Prompt and accurate diagnosis of cervical spine injury is important to prevent the catastrophic results that can be caused by undetected lesions. Delayed or missed diagnosis of cervical spine injury occurs with an incidence of 5 to 20% according to previous studies. In this study, we report four cases of cervical instability without initial radiologic evidence. These cases demonstrate that dynamic flexion and extension radiographies can be a proper choice of modality to diagnose and exclude the possibility of cervical instability in a patient with a suspicious ligament injury on the static radiographies following acute cervical trauma.

부비동 진균구의 임상적 고찰:대구지역 다기관 연구

여창기 대한비과학회 2005 Journal of rhinology Vol.12 No.2

교근에 발생한 해면상 혈관종 1예

여창기 대한이비인후과학회 2006 대한이비인후과학회지 두경부외과학 Vol.49 No.6

Intramuscular hemangiomas are uncommon tumors of the head and neck and when present, the masseter muscle is the most frequently involved site, although constituting only 0.8% of all hemangiomas. Diagnosis of intramuscular hemangioma is extremely difficult even with accurate preoperative imaging because it is not encountered frequently and is often confused with salivary gland stone, parotid neoplasm or other tumors. The definitive diagnosis is made by histological study of the surgical biopsy specimen. Treatment of choice is by complete surgical excision. This is the first case of intramuscular hemangioma of the masseter muscle reported in Korea. So I review the clinical, radiologic, histologic findings and treatment modalities of the intramuscular hemangioma. (Korean J Otolaryngol 2006;49:669-71)

비중격에 발생한 평활근종 치험 1예

여창기,박정엽,권성우,김익수 대한이비인후과학회 2001 대한이비인후과학회지 두경부외과학 Vol.44 No.8

두경부종양의 절제술 후 생긴 복수 결손 부위의 재건

여창기,김정규,김진수,박준식,이정형,조병채 대한이비인후과학회 1999 대한이비인후과학회지 두경부외과학 Vol.42 No.3