• Journal of Chest Surgery
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• 제48권3호
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• pp.193-198
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• 2015

Background: Patients on dialysis undergoing surgery belong to a high-risk group. Only a few studies have evaluated the outcome of major thoracic surgical procedures in dialysis patients. We evaluated the outcomes of pulmonary resection for non-small cell lung cancer (NSCLC) in patients on hemodialysis (HD). Methods: Between 2008 and 2013, seven patients on HD underwent pulmonary resection for NSCLC at our institution. We retrospectively reviewed their surgical outcomes and prognoses. Results: The median duration of HD before surgery was 55.0 months. Five patients underwent lobectomy and two patients underwent wedge resection. Postoperative morbidity occurred in three patients, including pulmonary edema combined with pneumonia, cerebral infarction, and delirium. There were no instances of in-hospital mortality, although one patient died of intracranial bleeding 15 days after discharge. During follow-up, three patients (one patient with pathologic stage IIB NSCLC and two patients with pathologic stage IIIA NSCLC) experienced recurrence and died as a result of the progression of the cancer, while the remaining three patients (with pathologic stage I NSCLC) are alive with no evidence of disease. Conclusion: Surgery for NSCLC in HD patients can be performed with acceptable perioperative morbidity. Good medium-term survival in patients with pathologic stage I NSCLC can also be expected. Pulmonary resection seems to be the proper treatment option for dialysis patients with stage I NSCLC.

• Archives of Plastic Surgery
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• 제32권5호
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• pp.561-566
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• 2005

Even though it is generalized to perform synchronous lip and nasal correction, there are some cases in need of secondary correction of cleft lip nose deformity. In these procedures, the lengthening of columella plays an important role. We performed eighteen cases of the secondary cleft lip nose deformity correction using two different methods from 1997 to 2003. The central lip flap was used in eight patients and V-Y advancement flap in ten patients. Additional procedures including reverse U-incision, interdomal fixation sutures and suspension sutures were used for correction of combined deformity. Silastic nasal retainers were kept in all patients for 6 months. Both of central lip flap and V-Y advancement flap seems to be a good technique for lengthening columellar soft tissue. But new columella after V-Y advancement flap appeared to be too narrow and a bit unnatural looking and central lip flap left additional scar on the upper lip although it was conspicuous. We think that central lip flap is a better technique in a case with wide philtrum and narrow columella and V-Y advancement flap can be another choice in a columella with sufficient width.

• Journal of Chest Surgery
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• 제44권1호
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• pp.51-57
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• 2011

Background: Up to now, lobectomy, bilobectomy and pneumonectomy combined with extensive lymph node dissection have been regarded as the standard procedures for non-small cell lung cancer (NSCLC). In high-risk patients, however, limited resection (LR) has been attempted as a salvage procedure, and, recently, indication for LR has been extended to selected cases with early-stage NSCLC. Material and Methods: Among the 773 patients who underwent surgical procedures for NSCLC in Seoul National University Bundang Hospital from May 2003 to December 2008, 43 patients received LR. Medical records of these patients were retrospectively reviewed. Results: Mean age at operation was $66.0{\pm}12.4$ years, and there were 30 males. Twenty-five patients underwent conservative limited resection (CLR) and 18 underwent intentional limited resection (ILR). Indications for CLR were multiple primary lung cancer in 9 (9/25, 36%) and severe concomitant diseases in 5 (5/25, 20%). Of these, 6 patients underwent segmentectomy and 19 received wedge resection. During the follow-up period of $28.0{\pm}17.8$ months, 15 patient developed recurrent lung cancer. ILR was selectively performed in lesions almost purely composed of ground glass opacity (${\geq}$95%), or in small solid lesions (${\leq}$2 cm). Of these, 11 patients underwent segmentectomy and 7 underwent wedge resection. During the follow-up period of $31.7{\pm}11.6$ months, no patient developed recurrence. Conclusion: Intermediate-term outcome of LR for early-stage lung cancer is comparable to that of standard operation. For the delineation of the indications and appropriate surgical techniques for LR, prospective randomized multi-institutional study may be expedient.

• Journal of Chest Surgery
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• 제44권1호
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• pp.25-31
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• 2011

Background: Mature autogenous arteriovenous fistulas have better long term patency and require fewer secondary interventions compared to arteriovenous prosthetic graft. Our Study evaluated vascular patency rates and incidence of interventions in autogenous arteriovenous fistulas and grafts. Material and Methods: A total of 166 vascular access operations were performed in 153 patients between December 2002 and November 2009. Thirty seven caeses were excluded due to primary access failure and loss of follow-up. One group of 92 autogenous arterioveous fistulas and the other group of 37 arteriovenous prosthetic grafts were evaluated retrospectively. Primary and secondary patency rates were estimated using the Kaplan-Meier method. Results: The primary patency rate (84%, 67%, 51% vs. 51%, 22%, 9% at 1, 3, 5 year; p=0.0000) and secondary patency rate (96%, 88%, 68% vs. 88%, 65%, 16% at 1, 3, 5 year; p=0.0009) were better in autogenous fistula group than prosthetic graft group. Interventions to maintain secondary patency were required in 23% of the autogenous fistula group (average 0.06 procedures/patient/year) and 65% of prosthetic graft group (average 0.21 procedures/patient/year). So the autogenous fistula group had fewer intervention rate than prosthetic graft group (p=0.01) The risk factor of primary patency was diabetus combined with ischemic heart disease and the secondary patency's risk factor was age. Conclusion: Autogenous arteriovenous fistulas showed better performance compared to prosthetic grafts in terms of primary & secondary patency and incidence of interventions.

• Journal of Korean Neurosurgical Society
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• 제59권1호
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• pp.17-25
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• 2016

Objective : Treatment of intracranial dural arteriovenous fistulas (dAVFs) remains a challenge. However, after introduction of Onyx, transarterial approach is the preferred treatment option in many centers. We report our experience of dAVFs embolization with special emphasis on transarterial approach. Methods : Seventeen embolization procedures were performed in 13 patients with dAVFs between Jan 2009 and Oct 2014. Clinical symptoms, location and type of fistulas, embolization methods, complications, radiological and clinical outcomes were evaluated using charts and PACS images. Results : All 13 patients had symptomatic lesions. The locations of fistulas were transverse-sigmoid sinus in 6, middle fossa dura in 4, cavernous sinus in 2, and superior sagittal sinus in 1 patient. Cognard types were as follows : I in 4, IIa in 2, IIa+IIb in 5, and IV in 2. Embolization procedures were performed ${\geq}2$ times in 3 patients. Nine patients were treated with transarterial Onyx embolization alone. One of these required direct surgical puncture of middle meningeal artery. Complete obliteration of fistulas was achieved in 11/13 (85%) patients. There were no complications except for 1 case of Onyx migration in cavernous dAVF. Modified Rankin scale score at post-operative 3 months were 0 in 11, and 3 in 2 patients. Conclusion : Transarterial Onyx embolization can be a first line therapeutic option in patients with dAVFs. However, transvenous approach should be tried first in cavernous sinus dAVF because of the risk of intracranial migration of liquid embolic materials. Furthermore, combined surgical endovascular approach can be considered as a useful option in inaccessible route.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제45권4호
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• pp.207-214
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• 2019

Objectives: Medically compromised patients often fear required dental surgical procedures that can increase the risk of medical emergency when combined with reduced tolerance for stress. A stress reduction protocol (SRP) helps doctors minimize treatment-related stress and improves patient management with minimum complications. Diabetes and co-morbid hypertension carry 4-fold risk of aggravation of cardiovascular emergencies and 7.2-fold risk of mortality. Diabetic neuropathy can result in difficult diagnosis of myocardial infarction and reduces chances of surviving a myocardial infarction compared with a non-diabetic person. The aim of the study was to assess the feasibility of a protocol for management of patients having both diabetes and hypertension who required minor oral surgery to minimize the rate of cardiovascular emergencies. Materials and Methods: A prospective study was conducted in 140 patients having both diabetes and hypertension who required minor oral surgical procedures. A systematic approachable protocol was designed for management of such patients. Results: Among 140 patients, 6 patients (4.3%) had cardiovascular complications, while 3 patients (1 with syncope and 2 with hypertension) did not require any intervention other than observation. Two patients were managed with aspirin and nitroglycerin, and 1 patient had possible myocardial infarction (overall incidence 0.7%) with chest pain, S-T segment elevation on electrocardiogram, and troponin level of 0.60 ng/mL. Conclusion: The proposed protocol helps to improve management of patients having both diabetes and hypertension. We recommend that patients with uncontrolled diabetes and uncontrolled hypertension and/or patients having history of cardiovascular complication should be treated in a medical facility with a readily available cardiology unit. This facilitates prompt response to emergency and instant implementation of treatment, helping to reduce morbidity and mortality.

• Journal of Korean Neurosurgical Society
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• 제65권4호
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• pp.523-530
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• 2022

Objective : To evaluate the safety and efficacy of an overlapped stenting-assisted coiling technique in treating vertebral artery dissecting aneurysm (VADA) via Low-profile Visualized Intraluminal Support (LVIS) stent-within-Neuroform EZ stent. Methods : From January 2017 to June 2019, 18 consecutive patients with VADAs (ruptured : unruptured=5 : 13) were treated with the overlapping stents assisted-coiling technique in our center. The overlapping manner was a Neuroform EZ stent being deployed first, followed by LVIS stents placement using the 'shelf' technique. The patients' clinical characteristics, technical feasibility and safety, and immediate and follow-up angiographic results were retrospectively reviewed. Results : Seventeen (94.4%) procedures were technically successful with an exact deployment of the stents and patent parent or perforator arteries. The immediate angiographies after procedure confirmed Raymond class I, II, and III occlusion of VADAs were in 12 (66.7%), two (11.1%), and four cases (22.2%), respectively. Post-procedural complications developed in one patient (5.6%) with minor brainstem infarctions, which resulted from an in-stent thrombosis during the procedure. Angiographic follow-up at 5.7 months (range 3 to 9 months) demonstrated Raymond class I and II occlusion were in all cases (100%). The modified Rankin Scale scores at 21.3 months (range 15 to 42 months) 0-2 in 17 cases (94.4%) and three in one case (5.6%). Conclusion : Overlapping stents via LVIS stent-within-Neuroform EZ stent combined with coiling is safe and effective for patients with VADA in the midterm results.

• 대한임상검사과학회지
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• 제56권2호
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• pp.105-114
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• 2024

임상검사실은 질관리 시스템(quality management system)을 구축하여 일정 수준 이상의 질 확보를 위해 노력하여야 한다. 그러나 검사실 환경은 매우 복잡하여 단일 정도관리 절차로는 다양한 유형의 오류를 감지하는데 충분하지 않을 수 있다. 환자 기반 실시간 정도관리(patient-based real-time quality control, PBRTQC)는 테스트 과정을 모니터링하기 위한 검사실 도구로써 Bull's 알고리즘, 정상치 평균, 이동 중앙값, 이동평균, 지수가중이동평균과 같은 알고리즘이 활용되고 있다. PBRTQC는 저렴한 비용, 교환 가능성, 지속적인 실시간 성능 모니터링, 분석 전 오류에 대한 민감도 등 기존 정도관리에 비해 많은 이점이 있다. 그러나 PBRTQC는 통계 알고리즘의 선택, 적절한 규칙과 프로토콜의 설계, 성능검증 등을 고려해야하므로 구현하기가 쉽지만은 않다. 본 리뷰에서는 PBRTQC의 기본 개념과 방법 및 절차에 대해 설명하였으며, 이를 통해 환자 기반 정도관리 시스템 구현을 위한 지침을 제시하고자 하였다. 이에 기존의 내부정도관리의 성능이 제한적일 경우 PBRTQC 절차를 병용하는 것을 제안하고자 한다. 본 리뷰에서는 임상적 평가는 배제되었으며, 향후 이에 대한 평가가 요구된다.

• 에너지공학
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• 제27권2호
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• pp.1-13
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• 2018

미세먼지 저감 및 에너지원 변환에 대한 정책 추진에 따라 천연가스를 연료로 하는 발전의 비중이 확대되고 있다. 복합화력발전 플랜트, 열병합발전 플랜트 등에서 천연가스 연료공급계통이 가스가 가열된 상태에서 고압으로 운용되고 있으므로, 누출사고를 예방하여 화재 및 폭발에 의해 사고를 방지하여야 한다. 본 연구에서는 API RP 581 RBI 코드를 기반으로 복합화력발전 플랜트의 천연가스 연료공급계통을 대상으로 위험도 평가를 수행하였다. API RBI 코드의 적용을 위해 평가 대상 계통의 라인 및 세그먼트를 구분하였다. 파손확률과 파손피해 산출을 위해 운전 데이터 및 입력 정보를 분석하였다. 설치 초기 시점 및 운전시간 경과에 따른 위험도 평가 결과 추이를 분석하였다. 코드 기반 평가 시 가스연료 공급계통은 두께 감육, 외부 손상, 기계적 피로 손상기구의 영향이 주로 반영되었다. 운전 시간이 경과함에 따라 단열재 하부 부식(CUI, Corrosion Under Insulation) 등에 의한 외부손상이 위험도를 상승시키는 원인으로 예상되었다.

• 한국수자원학회논문집
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• 제37권3호
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• pp.219-231
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• 2004

수중폭기장치로 저수지 성층을 파괴시켜 저수지 수질을 개선시키기 위한 방법이 최근 널리 이용되고 있다. 본 연구는 주요 성층 파괴기작인 Bubble Plume(공기 부력류)의 수리동역학적 거동특성과 플륨 간격에 따라 변하는 모멘텀 중첩효과가 성층파괴 효율에 어떠한 영향을 미치는지에 대하여 수행하였다. 이를 위해 전산유체(CFD) 소프트웨어를 이용한 2상(공기-물) 3차원의 탈성층모델을 개발했으며, 이로부터 계절에 따라 변하는 다양한 성층강도와 주입 공기량에 따라 변하는 비정상상태의 성층파괴 발달과정은 물론 최적 탈성층 효율을 갖는 플륨간격을 제안할 수 있었다. 모델검증을 위한 실험을 위해 대형 실험조를 개발했으며, 온도성층은 소금물을 이용했던 기존연구와는 달리 가열순환수를 이용한 자연성층을 재현시켜 수행하였다. 연구결과 탈성층 효율은 디퓨서 배치간격에 크게 영향을 받는 것으로 밝혀졌으며, 플륨간격이 수심의 약 1.5배 이내익 때 중첩영향이 강하게 일어났고, PN가 클수록 간격에 영향을 상대적으로 크게 받았다. 또한, 간격이 수심보다 작곤 때는 효율이 PN에 비례해서 선형적으로 증가한 반면 그 이상에서는 효율이 상대적으로 감소하면서 비선형적으로 증가하는 현상을 밝혀냈다. 이상의 연구결과를 통해 주입공기량은 PN가 약 1000, 디퓨서 배치간격은 수심의 1.5배일 때가 최적의 성층파괴 조건인 것으로 나타났다.