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Dive into the research topics where Yun Nah Lee is active.

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Featured researches published by Yun Nah Lee.


Endoscopy | 2014

Core biopsy needle versus standard aspiration needle for endoscopic ultrasound-guided sampling of solid pancreatic masses: a randomized parallel-group study

Yun Nah Lee; Jong Ho Moon; Hee Kyung Kim; Hyun Jong Choi; Moon Han Choi; Dong Choon Kim; Tae Hoon Lee; Sang-Woo Cha; Young Deok Cho; Sang-Heum Park

BACKGROUND AND STUDY AIMS An endoscopic ultrasound (EUS)-guided fine needle biopsy (EUS-FNB) device using a core biopsy needle was developed to improve diagnostic accuracy by simultaneously obtaining cytological aspirates and histological core samples. We prospectively compared the diagnostic accuracy of EUS-FNB with standard EUS-guided fine needle aspiration (EUS-FNA) in patients with solid pancreatic masses. PATIENTS AND METHODS Between January 2012 and May 2013, consecutive patients with solid pancreatic masses were prospectively enrolled and randomized to undergo EUS-FNB using a core biopsy needle or EUS-FNA using a standard aspiration needle at a single tertiary center. The specimen was analyzed by onsite cytology, Papanicolaou-stain cytology, and histology. The main outcome measure was diagnostic accuracy for malignancy. The secondary outcome measures were: the median number of passes required to establish a diagnosis, the proportion of patients in whom the diagnosis was established with each pass, and complication rates. RESULTS The overall accuracy of combining onsite cytology with Papanicolaou-stain cytology and histology was not significantly different for the FNB (n = 58) and FNA (n = 58) groups (98.3 % [95 %CI 94.9 % - 100 %] vs. 94.8 % [95 %CI 91.9 % - 100 %]; P = 0.671). Compared with FNA, FNB required a significantly lower median number of needle passes to establish a diagnosis (1.0 vs. 2.0; P < 0.001). On subgroup analysis of 111 patients with malignant lesions, the proportion of patients in whom malignancy was diagnosed on the first pass was significantly greater in the FNB group (72.7 % vs. 37.5 %; P < 0.001). CONCLUSIONS The overall accuracy of FNB and FNA in patients with solid pancreatic masses was comparable; however, fewer passes were required to establish the diagnosis of malignancy using FNB.This study was registered on the UMIN Clinical Trial Registry (UMIN000014057).


Gut and Liver | 2014

Long-Term Efficacy of Endoscopic Submucosal Dissection Compared with Surgery for Early Gastric Cancer: A Retrospective Cohort Study

Dae Yong Kim; Su Jin Hong; Gyu Seok Cho; Gui Ae Jeong; Hee Kyung Kim; Jae Pil Han; Yun Nah Lee; Bong Min Ko; Moon Sung Lee

Background/Aims This study aimed to compare the outcomes of endoscopic submucosal dissection (ESD) and gastrectomy based on the two sets of indications for ESD, namely guideline criteria (GC) and expanded criteria (EC). Methods Between January 2004 and July 2007, 213 early gastric cancer (EGC) patients were enrolled in this study. Of these patients, 142 underwent ESD, and 71 underwent gastrectomy. We evaluated the clinical outcomes of these patients according to the criteria. Results The complication rates in the ESD and gastrectomy groups were 8.5% and 28.2%, respectively. The duration of hospital stay was significantly shorter in the ESD group than the gastrectomy group according to the GC and EC (p<0.001 and p<0.001, respectively). There was no recurrence in the ESD and gastrectomy groups according to the GC, and the recurrence rates in the ESD and gastrectomy groups were 4.7% and 0.0% according to the EC, respectively (p=0.279). The occurrence rates of metachronous cancer in the ESD and gastrectomy groups were 5.7% and 5.0% according to the GC (p=1.000) and 7.5% and 0.0% according to the EC (p=0.055), respectively. Conclusions Based on safety, duration of hospital stay, and long-term outcomes, ESD may be an effective and safe first-line treatment for EGC according to the EC and GC.


Endoscopy | 2012

Direct peroral cholangioscopy using an ultraslim upper endoscope for management of residual stones after mechanical lithotripsy for retained common bile duct stones.

Yun Nah Lee; Jong Ho Moon; Hyun Jong Choi; Min Sk; Kim Hi; Tae Hee Lee; Yd Cho; S. H. Park; S. J. Kim

BACKGROUND AND STUDY AIMS The incidence of residual stones after mechanical lithotripsy for retained common bile duct (CBD) stones is relatively high. Peroral cholangioscopy using a mother-baby system may be useful for confirming complete extraction of stones, but has several limitations regarding routine use. We evaluated the role of direct peroral cholangioscopy (DPOC) using an ultraslim upper endoscope for the evaluation and removal of residual CBD stones after mechanical lithotripsy. PATIENTS AND METHODS From August 2006 to November 2010, 48 patients who had undergone mechanical lithotripsy for retained CBD stones with no evidence of filling defects in balloon cholangiography were recruited. The bile duct was inspected by DPOC after balloon cholangiography. Detected residual CBD stones were directly retrieved with a basket or balloon catheter under DPOC. The incidence of residual stones detected by DPOC, and the success rate of residual stone retrieval under DPOC were investigated. RESULTS DPOC was successfully performed in 46 of the 48 patients (95.8%). Of these, 13 patients (28.3%) had residual CBD stones (mean number 1.4, range 1-3; mean diameter 4.5 mm, range 2.3-9.6). The residual stones were removed directly under DPOC in 11 of these patients (84.6%). There were no complications associated with DPOC or stone removal. CONCLUSION DPOC using an ultraslim upper endoscope is a useful endoscopic procedure for the evaluation and extraction of residual stones after mechanical lithotripsy for retained CBD stones.


Clinical and molecular hepatology | 2013

The usefulness of transient elastography, acoustic-radiation-force impulse elastography, and real-time elastography for the evaluation of liver fibrosis

Jong Ho Chung; Hyung Su Ahn; Sang Gyune Kim; Yun Nah Lee; Young Seok Kim; Soung Won Jeong; Jae Young Jang; Sae Hwan Lee; Hong Soo Kim; Boo Sung Kim

Background/Aims Several noninvasive methods have recently been developed for the evaluation of liver fibrosis. The accuracy of transient elastography (TE), acoustic-radiation-force impulse (ARFI) elastography, and real-time elastography (RTE) in predicting liver fibrosis were evaluated. Methods Seventy-four patients who had undergone a liver biopsy within the previous 6 months were submitted to evaluation with TE, ARFI, and RTE on the same day. Results There were significant correlations between fibrosis stage and liver stiffness measurement (LSM) using the three tested methods: TE, r2=0.272, P=0.0002; ARFI, r2=0.225, P=0.0017; and RTE, r2=0.228, P=0.0015. The areas under the receiver operating characteristic curves (AUROC) for the diagnosis of significant fibrosis (≥F2, Metavir stage) by TE, ARFI, RTE, TE/platelet count (PLT), velocity of shear wave (Vs)/PLT, and elasticity score (Es)/PLT were 0.727, 0.715, 0.507, 0.876, 0.874, and 0.811, respectively. The AUROC for the diagnosis of cirrhosis by TE, ARFI, RTE, TE/PLT, Vs/PLT, and Es/PLT were 0.786, 0.807, 0.767, 0.836, 0.819, and 0.838, respectively. Comparisons of AUROC between all LSMs for predicting significant fibrosis (≥F2) produced the following results: TE vs. RTE, P=0.0069; ARFI vs. RTE, P=0.0277; and TE vs. ARFI, P=0.8836. Applying PLT, the ability of each LSM to predict fibrosis stage significantly increased: TE/PLT vs. TE, P=0.0004; Vs/PLT vs. ARFI, P=0.0022; and Es/PLT vs. RTE, P<0.0001. However, the ability to predict cirrhosis was not enhanced, combining LSM and PLT. Conclusions TE and ARFI may be better methods for predicting significant liver fibrosis than RTE. This predictive ability increased significantly when accounting for platelet count. However, all of the measures had comparable efficacies for predicting cirrhosis.


Gastrointestinal Endoscopy | 2016

A newly modified access balloon catheter for direct peroral cholangioscopy by using an ultraslim upper endoscope (with videos)

Yun Nah Lee; Jong Ho Moon; Hyun Jong Choi; Hyun Su Kim; Moon Han Choi; Dong Choon Kim; Tae Hoon Lee; Sang-Woo Cha; Young Deok Cho; Sang-Heum Park

BACKGROUND AND AIMS Direct peroral cholangioscopy (POC) by using an ultraslim upper endoscope has been increasingly applied for diagnosis and treatment of diverse biliary diseases. Recently, an intraductal balloon catheter has been used commonly to guide the flexible ultraslim endoscope. However, accessibility into the bile duct remains a limitation of the procedure. The aim of this study was to evaluate the feasibility and success rate of an intraductal balloon-guided direct POC by using an ultraslim endoscope with a newly modified 5F balloon catheter. METHODS In total, 36 patients with biliary obstruction were included prospectively for a direct POC by using an ultraslim endoscope with a newly modified intraductal 5F balloon catheter. The main outcome measure was technical success, defined as successful advancement of the ultraslim endoscope into the obstructed segment of the biliary tree or the bifurcation. Secondary outcomes were mean time for the total procedure, intubation into the common bile duct and advancement up to the target site after intubation of the ultraslim endoscope, technical success rates of diagnostic and therapeutic interventions, and adverse events. RESULTS The intraductal balloon-guided direct POC using a newly modified 5F balloon catheter was completed successfully in 35 of 36 patients (97.2%). The mean times for total procedure, intubation into the distal common bile duct, and advancement up to the obstructed bile duct segment were 27.3 ± 7.2, 2.2 ± 0.5, and 0.8 ± 0.4 minutes, respectively. In total, 49 interventions were performed in 35 patients, excluding 1 patient in whom we failed to perform direct POC. Technical success of the interventions was achieved with 44 of 49 procedures (89.8%). No adverse events, including cholangitis, were observed. CONCLUSIONS A newly modified 5F balloon catheter seemed to facilitate performing intraductal balloon-guided direct POC for direct visual examination of the bile duct in patients with biliary obstruction. Continued development of endoscopes and accessories are expected to further improve the performance of direct POC.


The Korean Journal of Hepatology | 2011

Vogt-Koyanagi-Harada disease occurring during pegylated interferon-α2b and ribavirin combination therapy for chronic hepatitis C.

Jae Hee Lim; Yun Nah Lee; Young Seok Kim; Sang Gyune Kim; Seung Won Jeong; Jae Young Jang; Hong Soo Kim; Sae Hwan Lee; Tae Kwann Park

Vogt-Koyanagi-Harada (VKH) disease is a multisystem syndrome characterized by ocular (uveitis and retinal detachment), neurological (headache, tinnitus, and meningitis), and integumentary (vitiligo, alopecia, and poliosis) involvement. Although the pathogenesis of VKH disease is not well understood, an autoimmune T-cell response to a melanocyte-associated antigen is considered to be a cause of VKH disease. The complex immunological response to interferon and ribavirin may induce or exacerbate the autoimmune condition; however, VKH disease is a very rare complication associated with interferon therapy in chronic hepatitis C. We report a case of VKH disease occurring during pegylated interferon-α2b and ribavirin combination therapy for chronic hepatitis C.


Journal of Digestive Diseases | 2016

EUS‐guided FNA and FNB after on‐site cytologic evaluation in gastric subepithelial tumors

Jae Pil Han; Tae Hee Lee; Su Jin Hong; Hee Kyung Kim; Hyung Min Noh; Yun Nah Lee; Hyun Jong Choi

Acquiring adequate tissue for immunohistochemical (IHC) analysis is important in the differential diagnosis of subepithelial tumors (SETs). In this study, we aimed to compare the diagnostic yield based on IHC analysis between endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) and EUS‐guided fine needle biopsy (EUS‐FNB) after on‐site cytological evaluation for cellularity in gastric SETs.


Journal of Gastroenterology and Hepatology | 2015

Usefulness of endoscopic ultrasound‐guided sampling using core biopsy needle as a percutaneous biopsy rescue for diagnosis of solid liver mass: Combined histological‐cytological analysis

Yun Nah Lee; Jong Ho Moon; Hee Kyung Kim; Hyun Jong Choi; Moon Han Choi; Dong Choon Kim; Tae Hee Lee; Tae Hoon Lee; Sang-Woo Cha; Sang Gyune Kim; Young Seok Kim

Endoscopic ultrasound (EUS)‐guided fine needle aspiration (EUS‐FNA) is one of the alternative methods for tissue sampling of liver solid mass. However, the diagnostic efficacy using cytology alone was limited. In this study, we evaluate the diagnostic accuracy of EUS‐guided fine needle biopsy (EUS‐FNB) as a percutaneous biopsy rescue for liver solid mass.


Gut and Liver | 2014

Current Status of Endoscopic Papillectomy for Ampullary Tumors

Jong Ho Moon; Hyun Jong Choi; Yun Nah Lee

Detection of tumors of the ampulla of Vater, including ampullary adenoma, has been improved by routine screening endoscopic procedures and imaging modalities. Endoscopic resection by endoscopic papillectomy is rapidly replacing classic surgical resection and is a less invasive procedure. Endoscopic resection can have a role not only in the final histopathologic diagnosis but also as a definite therapeutic option. However, the indications for endoscopic resection are not fully established, and endoscopic procedures are not standardized. Significant complications, including severe pancreatitis, intractable bleeding and duodenal perforation, are rare but can occur, especially in less experienced hands. Severe pancreatitis is the most feared complication, but it can be prevented by pancreatic duct stent insertion in most cases. However, in some cases, pancreatic stenting can be challenging after resection. Incomplete resections are sometimes performed to avoid complications. Endoscopic surveillance is also important for identifying and managing remnant adenomatous tissue or recurrent lesions. Further technical development is needed to expand the indications for this procedure, minimize complications and ensure a high success rate.


Digestive Endoscopy | 2017

Efficacy of midazolam- versus propofol-based sedations by non-anesthesiologists during therapeutic endoscopic retrograde cholangiopancreatography in patients aged over 80 years

Su Jung Han; Tae Hoon Lee; Sang-Heum Park; Young Sin Cho; Yun Nah Lee; Yunho Jung; Hyun Jong Choi; Il-Kwun Chung; Sang-Woo Cha; Jong Ho Moon; Young Deok Cho; Sun-Joo Kim

As society ages, the need for endoscopic retrograde cholangiopancreatography (ERCP) is increasing. This prospective comparative study evaluated the safety and efficacy of midazolam‐ versus propofol‐based sedations by non‐anesthesiologists during therapeutic ERCP in patients over 80 years of age.

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Hyun Jong Choi

Soonchunhyang University

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Jong Ho Moon

Soonchunhyang University

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Tae Hoon Lee

Seoul National University

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Young Deok Cho

Soonchunhyang University

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Sang-Heum Park

Soonchunhyang University

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Sang-Woo Cha

Soonchunhyang University

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Moon Han Choi

Soonchunhyang University

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Sun-Joo Kim

Gyeongsang National University

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Sang Gyune Kim

Soonchunhyang University

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