투석 환자에서 복강경 근치적 신적출술 및 신요관적출술

유구한,전승현,김태환,이형래 대한비뇨의학회 2007 Investigative and Clinical Urology Vol.48 No.8

전립선암 진단을 위한 경직장초음파검사에서 저반향병소와 혈류증가의 의의

유구한,전승현,임주원,장성구 대한비뇨의학회 2007 Investigative and Clinical Urology Vol.48 No.2

Renal Function Outcomes in Patients Undergoing Open or Laparoscopic Radical Nephrectomy

유구한,이형래,장성구,전승현 대한비뇨의학회 2009 Investigative and Clinical Urology Vol.50 No.6

Purpose: We compared renal function outcomes in patients undergoing open or laparoscopic radical nephrectomy. Materials and Methods: Seventy-one patients undergoing open or laparoscopic radical nephrectomy for kidney disease with a normal contralateral kidney were identified between January 2004 and December 2007. Renal function was calculated by using the Cockcroft-Gault formula. Serial renal functions were checked from the day before surgery to 1 year after surgery. Exclusion criteria were preexisting renal insufficiency, urinary stone disease, and pancreatic and liver disorders. Results: Forty-one and 30 patients were treated with open radical nephrectomy or laparoscopic radical nephrectomy, respectively. The operative time and urine output of patients who underwent open and laparoscopic radical nephrectomy were 211.7±5.8 and 330.8±15.6 and 196.4±19.6 and 130.7±12.1, respectively (p=0.001, p=0.013). The glomerular filtration rates of patients who underwent open or laparoscopic radical nephrectomy were insignificant from baseline to postoperative day 360 (p>0.05). Conclusions: No significant differences in renal function were detected in the groups of patients who underwent open or laparoscopic radical nephrectomy from baseline to long-term follow-up. Purpose: We compared renal function outcomes in patients undergoing open or laparoscopic radical nephrectomy. Materials and Methods: Seventy-one patients undergoing open or laparoscopic radical nephrectomy for kidney disease with a normal contralateral kidney were identified between January 2004 and December 2007. Renal function was calculated by using the Cockcroft-Gault formula. Serial renal functions were checked from the day before surgery to 1 year after surgery. Exclusion criteria were preexisting renal insufficiency, urinary stone disease, and pancreatic and liver disorders. Results: Forty-one and 30 patients were treated with open radical nephrectomy or laparoscopic radical nephrectomy, respectively. The operative time and urine output of patients who underwent open and laparoscopic radical nephrectomy were 211.7±5.8 and 330.8±15.6 and 196.4±19.6 and 130.7±12.1, respectively (p=0.001, p=0.013). The glomerular filtration rates of patients who underwent open or laparoscopic radical nephrectomy were insignificant from baseline to postoperative day 360 (p>0.05). Conclusions: No significant differences in renal function were detected in the groups of patients who underwent open or laparoscopic radical nephrectomy from baseline to long-term follow-up.

A Hybrid Treatment for Large Bladder Stones: Laparoscopic Cystolithotomy with Combined Direct Visual Lithotripsy

이중근,유구한,김태환,민경은,전승현 대한비뇨의학회 2009 Investigative and Clinical Urology Vol.50 No.9

There are diverse surgical methods for treating large bladder stones, such as transurethral cystolithotripsy (TUCL), percutaneous suprapubic cystolithotripsy (PCCL), open surgery, and laparoscopic methods. We report here a case of two large bladder stones treated by using a combined surgical method of a laparoscopic approach and direct visual lithotripsy.

비뇨기과 복강경 수술 후 발생하는 내과적 합병증 발생에 영향을 미치는 인자에 대한 연구

이상협,유구한,민경은,이형래,장성구,전승현 대한비뇨의학회 2009 Investigative and Clinical Urology Vol.50 No.8

Purpose: Factors related to nonurologic postoperative complications of laparoscopic surgery in the urologic area were examined. The most significant factors were isolated and analyzed to establish ways to reduce the complication rate. Materials and Methods: The medical records of 154 patients who had undergone laparoscopic surgery between March 2004 and March 2008 were reviewed. Age, anesthetic time, American Society of Anesthesiologists physical status classification, operative difficulty, blood loss (ml), body mass index (BMI), and complications were assessed. Complications were divided into 5 groups based on the modified Clavien classification. Grade 0 to 1 was defined as a no complication group and grades 2 to 5 as a complication group. The Armitage trend test was performed to study the relations between the factors and the complications. Univariate and multivariate analyses were performed to determine the risk ratio of each of the factors and the most significant factors. Results: Complications tended to increase as the anesthetic risk and anesthetic time increased (p=0.011, 0.013, respectively). Operative difficulty and blood loss were related to complications (p=0.018, p<0.001, respectively). The univariate analysis revealed that blood loss of more than 400 ml compared with less than 200 ml had a risk ratio of 18.2. Moderate and hard operative difficulties had a significant risk ratio of around 4, and high anesthetic risk had a high risk rate of around 5. The multivariate analysis showed that blood loss and high anesthetic risk were independent risk factors of complications. Conclusions: Blood loss and high anesthetic risk proved to be independent factors that are associated with complications. Surgeons must keep in mind the patient’s anesthetic risk and try to minimize blood loss during the operation to reduce complications after a laparoscopic surgery.

소형항공기용 블랙박스의 관통저항력 해석 및 실험

이석규,유구현,양성철,김진천 한국항공우주학회 2005 한국항공우주학회 학술발표회 논문집 Vol.- No.-

열습환경을 고려한 항공기용 레이돔 볼트 체결부의 베어링 강도에 관한 연구

김호일,유구현,김준,김광민,이규송,박영주,박범준,유홍균,Kim, Ho Il,Ryu, Guh Yun,Kim, Joon,Kim, Kwang Min,Lee, Kyu Song,Park, Young Ju,Park, Byum Jun,Ryu, Hong Kyun 대한기계학회 2017 大韓機械學會論文集A Vol.24 No.2

This research investigated the hygrothermal effect on the strength of bolt jointed section and moisture contents of composites exposed to hygrothermal environment for composite aircraft radome. The decrease in strength in the test environment is mainly attributed to the change in the material properties of the matrix due to temperature and moisture. The composite specimens were tested in three different environmental conditions: RTD(room temperature and dry), CTD(cold temperature and dry) and ETW(elevated temperature and wet). The failure mode of the bolt jointed composite specimens were studied using tests and finite element analysis. Finite element analysis reasonably predicted the failure load and mode of the joints. A reliability-based design was carried out for the bolt jointed composites of radome. 본 연구에서는 항공기용 레이돔에 적용되는 복합재의 볼트 체결부 강도에 대한 온도 및 습도 환경의 영향을 연구하였으며 열습환경에 노출된 레이돔 체결부에 대해 수분흡수율을 구하고, 온도와 습도환경에 따른 체결부 강도의 물성변화를 확인하였다. 이때 시편은 환경조건을 고려하여 상온건조(RTD), 고온고습(EWT), 저온건조(CTD) 세 가지로 구분하였으며 볼트 체결부의 파손하중 및 파손모드를 결정하기 위한 실험과 유한요소해석을 수행하였다. 유한요소해석의 결과가 체결부 강도와 파손모드에서 실험결과와 잘 일치하였으며 체결부 파손강도 예측이 가능한 효과적인 방법으로 확인하였다.

Analysis of factors affecting spontaneous expulsion of ureteral stones that may predict unfavorable outcomes during watchful waiting periods: What is the influence of diabetes mellitus on the ureter?

최태수,유구한,최승권,김동수,이동기,민경은,전승현,이형래,정인경 대한비뇨의학회 2015 Investigative and Clinical Urology Vol.56 No.6

Purpose: The aim of our study was to evaluate the association of several factors with spontaneous stone expulsion, including ureteralstone characteristics (size, location, hydronephrosis, perinephric stranding), types of medications prescribed (α-blocker, lowdosesteroid), and other possible demographic and health-history factors (gender, age, serum creatinine, underlying diabetes mellitus[DM], and hypertension). Materials and Methods: A total of 366 patients with ureteral stones were enrolled. All patients underwent watchful waitingwithout any invasive procedures. Initial diagnoses of ureteral stones were confirmed by computed tomography scans, which weretaken at approximately 1-month intervals to check for stone expulsion. Univariate and multivariate analyses were conducted toidentify significant factors that contributed to stone expulsion. Results: Among 366 patients, 335 patients (91.5%) experienced spontaneous stone passage during a mean follow-up period of2.95±2.62 weeks. The patients were divided into two groups depending on the success of spontaneous stone passage. Univariateanalyses revealed that stone location (p=0.003), stone size (p=0.021), and underlying DM (p<0.001) were significant predictors ofstone passage. Multivariate analyses confirmed that stone size (p=0.010), stone location (p=0.008), and underlying DM (p=0.003)were independent predictive factors affecting stone passage. Conclusions: Stone size, location, and underlying DM were confirmed to be significant predictive factors for spontaneous passageof ureteral stones. Urologists should consider active procedures, such as shock wave lithotripsy or ureteroscopy, rather than conservativemanagement in patients presenting with proximally located stones, large ureteral stones, or underlying DM.

소형항공기용 블랙박스의 극한충격해석 및 실험

이석규,유구현,양성철,김진천,이상욱 한국항공우주학회 2006 한국항공우주학회 학술발표회 논문집 Vol.- No.-

비만도에 따른 개복 신적출술과 복강경 신적출술의 결과

이중근,유구한,민경은,장성구,전승현 대한비뇨의학회 2009 Investigative and Clinical Urology Vol.50 No.10

Purpose: The aim of this research was to compare surgical outcomes and complications of obese and non-obese patients who underwent open radical nephrectomy (ORN) and laparoscopic radical nephrectomy (LRN). Materials and Methods: The data of 26 ORN patients and 30 LRN patients between January 2006 and December 2008 were analyzed. Patients with a body mass index (BMI) of 25.0 kg/m2 or more were defined as obese, and those with a BMI of <25.0 kg/m2 were defined as non-obese. All patients were divided into two groups according to the criteria above to compare demographic and clinical and pathologic parameters. Results: The mean BMIs of the 15 obese patients in the ORN group and the 13 obese patients in the LRN group were 26.8±1.1 and 27.7±2.4, respectively. LRN was enormously effective for lowering estimated blood loss (EBL) and postoperative days compared with ORN. Operation times and EBL in ORN were affected by obesity, both of which were increased. In contrast, the data of both LRN groups indicated similar outcomes. The perioperative data of obese patients revealed LRN to have reduced blood loss (143.0±62.7 vs. 446.7±222.4 ml, p=0.001) and not significantly different postoperative days (7.3±2.2 vs. 8.4±1.5 days, p=0.065). Operation time, however, did not differ significantly among obese patients between ORN and LRN. The complications due to LRN had no relation with obesity, whereas ORN had an increased complications rate (34.6% vs. 3.8%). Conclusions: This study shows that LRN is more effective than ORN for both obese and non-obese patients with regard to perioperative outcomes and complication rates. Purpose: The aim of this research was to compare surgical outcomes and complications of obese and non-obese patients who underwent open radical nephrectomy (ORN) and laparoscopic radical nephrectomy (LRN). Materials and Methods: The data of 26 ORN patients and 30 LRN patients between January 2006 and December 2008 were analyzed. Patients with a body mass index (BMI) of 25.0 kg/m2 or more were defined as obese, and those with a BMI of <25.0 kg/m2 were defined as non-obese. All patients were divided into two groups according to the criteria above to compare demographic and clinical and pathologic parameters. Results: The mean BMIs of the 15 obese patients in the ORN group and the 13 obese patients in the LRN group were 26.8±1.1 and 27.7±2.4, respectively. LRN was enormously effective for lowering estimated blood loss (EBL) and postoperative days compared with ORN. Operation times and EBL in ORN were affected by obesity, both of which were increased. In contrast, the data of both LRN groups indicated similar outcomes. The perioperative data of obese patients revealed LRN to have reduced blood loss (143.0±62.7 vs. 446.7±222.4 ml, p=0.001) and not significantly different postoperative days (7.3±2.2 vs. 8.4±1.5 days, p=0.065). Operation time, however, did not differ significantly among obese patients between ORN and LRN. The complications due to LRN had no relation with obesity, whereas ORN had an increased complications rate (34.6% vs. 3.8%). Conclusions: This study shows that LRN is more effective than ORN for both obese and non-obese patients with regard to perioperative outcomes and complication rates.