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Featured researches published by Keun Soo Ahn.


Annals of Surgery | 2013

Benefit of systematic segmentectomy of the hepatocellular carcinoma: revisiting the dye injection method for various portal vein branches.

Keun Soo Ahn; Koo Jeong Kang; Tae Jun Park; Yong Hoon Kim; Tae Jin Lim; Jung Hyeok Kwon

Background: Systematic segmentectomy is useful in treating small hepatocellular carcinoma in the cirrhotic liver. However, accomplishment of an exact systematic segmentectomy still remains a challenging procedure because of the variable anatomy of portal branches. We evaluated the usefulness of the dye injection method for systematic segmentectomy, which focuses on the various patterns of portal vein (PV) branches feeding the tumor. Methods: From January 2001 to May 2011, systematic segmentectomy by the dye injection method was performed in 70 patients. We evaluated the efficiency of systematic segmentectomy by ultrasonogram-guided dye injection into the portal branches that feed the tumor-bearing segments. The type of tumor-feeding PV branch, perioperative outcome, and survival rates were analyzed retrospectively. Results: There were variations in the PV branches that fed the masses in 70 patients in whom the dye injection method for anatomical segmentectomy was tried. Forty masses (54.8%) were fed by a single main PV branch (type 1), 17 masses (23.3%) by a couple of PV branches (type 2), and 11 masses (15.1%) were supplied partially by single PV branch (type 3). In 5 patients (7.1%), masses were supplied by several small distributed PVs (type 4). For types 1 and 2, the tumor-bearing segments were resected anatomically with the help of staining; type 3 was partially stained and as the opposite side was not discrete, it was demarcated through counterstaining; and in type 4, dye injection could not be performed. Anatomical systematic segmentectomy was obtained in types 1 to 3; however, nonanatomical resection was inevitable for type 4. The 3- and 5-year overall survival rates were 80.5% and 67.2%, respectively, and the 3- and 5-year disease-free survival rates were 61.5% and 42.5%, respectively. The anatomical segmentectomy group showed better overall and disease-free survival than the nonanatomical group, even though it is not significant statistically. Conclusion: Systematic segmentectomy by the dye injection method overcomes the variation in PV tributaries in the segments and can be done according to the natural branching pattern of PVs.


World Journal of Gastroenterology | 2017

Anatomical resection of hepatocellular carcinoma: A critical review of the procedure and its benefits on survival

Koo Jeong Kang; Keun Soo Ahn

Hepatocellular carcinoma (HCC) is the sixth most common type of cancer and the third most frequent cause of cancer-related death. Advances in preoperative assessment of HCC (e.g., imaging studies and liver function tests), surgical techniques, and postoperative care have improved the surgical outcomes and survival of patients who undergo hepatic resection for HCC. However, in the last 20 years, the long-term survival after hepatectomy has remained unsatisfactory owing to the high rates of local recurrence and multicentric occurrence. Anatomical liver resection (AR) was introduced in the 1980s. Although several studies have revealed tangible benefits of AR for HCC, these benefits are still debated. Because most HCCs occur in patients with liver cirrhosis and poor hepatic function, there are many factors that affect survival, including the surgical method. Nevertheless, many studies have documented the perioperative and long-term benefits of AR in various conditions. In this article, we review the results of several recently published, well-designed comparative studies of AR, to investigate whether AR provides real benefits on survival outcomes. We also discuss the potential pitfalls associated with this approach.


Journal of Hepato-biliary-pancreatic Sciences | 2017

The “right” way is not always popular: comparison of surgeons’ perceptions during laparoscopic cholecystectomy for acute cholecystitis among experts from Japan, Korea and Taiwan

Taizo Hibi; Yukio Iwashita; Tetsuji Ohyama; Goro Honda; Masahiro Yoshida; Tadahiro Takada; Ho Seong Han; Tsann Long Hwang; Satoshi Shinya; Kenji Suzuki; Akiko Umezawa; Yoo Seok Yoon; In Seok Choi; Wayne Shih Wei Huang; Kuo Hsin Chen; Fumihiko Miura; Manabu Watanabe; Yuta Abe; Takeyuki Misawa; Yuichi Nagakawa; Dong Sup Yoon; Jin Young Jang; Hee Chul Yu; Keun Soo Ahn; Song Cheol Kim; In Sang Song; Ji Hoon Kim; Sung Su Yun; Seong Ho Choi; Yi Yin Jan

Generally, surgeons’ perceptions of surgical safety are based on experience and institutional policy. Our recent pilot survey demonstrated that the acceptable duration of surgery and criteria for open conversion during laparoscopic cholecystectomy (LC) vary among workplaces.


Journal of Hepato-biliary-pancreatic Sciences | 2016

What are the appropriate indicators of surgical difficulty during laparoscopic cholecystectomy? Results from a Japan‐Korea‐Taiwan multinational survey

Yukio Iwashita; Tetsuji Ohyama; Goro Honda; Taizo Hibi; Masahiro Yoshida; Fumihiko Miura; Tadahiro Takada; Ho Seong Han; Tsann Long Hwang; Satoshi Shinya; Kenji Suzuki; Akiko Umezawa; Yoo Seok Yoon; In Seok Choi; Wayne Shih Wei Huang; Kuo Hsin Chen; Manabu Watanabe; Yuta Abe; Takeyuki Misawa; Yuichi Nagakawa; Dong Sup Yoon; Jin Young Jang; Hee Chul Yu; Keun Soo Ahn; Song Cheol Kim; In Sang Song; Ji Hoon Kim; Sung Su Yun; Seong Ho Choi; Yi Yin Jan

Serious complications continue to occur in laparoscopic cholecystectomy (LC). The commonly used indicators of surgical difficulty such as the duration of surgery are insufficient because they are surgeon and institution dependent. We aimed to identify appropriate indicators of surgical difficulty during LC.


Korean Journal of Hepato-Biliary-Pancreatic Surgery | 2011

The impact of old age on surgical outcomes after pancreaticoduodenectomy for distal bile duct cancer.

Je Wook Shin; Keun Soo Ahn; Yong Hoon Kim; Koo Jeong Kang; Tae Jin Lim

Backgrounds/Aims To compare surgical results and survival of two groups of patients, age ≥70 vs. age <70, who underwent pancreaticoduodenectomy and to identify the safety of this procedure for elderly patients for the treatment of distal common bile duct (CBD) cancer. Methods Between January 2003 and December 2009, 55 patients who underwent pancreaticoduodenectomy for the treatment of distal CBD cancer at Keimyung University Dong San Medical Center were enrolled in our study. Results Of 55 patients, 28 were male and 27 female. Nineteen were over 70 years old (older group) and 36 were below 70 years (younger group). The mean ages of the two groups of patients were 73.5 years and 60.5 years respectively. Although patients of the older group had significantly more comorbid diseases, perioperative results including operation time, amount of intraoperative bleeding, duration of postoperative hospital stay and postoperative complications were not significantly different. A higher level (more than 5 mg/dl) of preoperative initial bilirubin showed significant correlations with operative morbidity by univariate analysis, and age was not an independent risk factor of operative morbidity. Overall 5 year survival of older and younger groups were 45.9% and 39.5% respectively (p=0.671) and disease-free 5-year survival were 31.7% and 31.1%, respectively (p=0.942). Conclusions Surgical outcomes of elderly patients were similar to those of younger patients, despite a higher incidence of comorbid disease. This results shows that pancreaticoduodenectomy can be applied safely to elderly patients.


Journal of Hepato-biliary-pancreatic Sciences | 2017

An opportunity in difficulty: Japan–Korea–Taiwan expert Delphi consensus on surgical difficulty during laparoscopic cholecystectomy

Yukio Iwashita; Taizo Hibi; Tetsuji Ohyama; Goro Honda; Masahiro Yoshida; Fumihiko Miura; Tadahiro Takada; Ho Seong Han; Tsann Long Hwang; Satoshi Shinya; Kenji Suzuki; Akiko Umezawa; Yoo Seok Yoon; In Seok Choi; Wayne Shih Wei Huang; Kuo Hsin Chen; Manabu Watanabe; Yuta Abe; Takeyuki Misawa; Yuichi Nagakawa; Dong Sup Yoon; Jin Young Jang; Hee Chul Yu; Keun Soo Ahn; Song Cheol Kim; In Sang Song; Ji Hoon Kim; Sung Su Yun; Seong Ho Choi; Yi Yin Jan

We previously identified 25 intraoperative findings during laparoscopic cholecystectomy (LC) as potential indicators of surgical difficulty per nominal group technique. This study aimed to build a consensus among expert LC surgeons on the impact of each item on surgical difficulty.


World Journal of Surgery | 2015

Impact of Preoperative ERCP on Laparoscopic Cholecystectomy: A Case-Controlled Study with Propensity Score Matching

Keun Soo Ahn; Yong Hoon Kim; Koo Jeong Kang; Tae-Seok Kim; Kwang Bum Cho; Eun Soo Kim

BackgroundAlthough inflammation induced by endoscopic retrograde cholangiopancreatography (ERCP) may affect laparoscopic cholecystectomy (LC), making the procedure more difficult, clinical impact of ERCP on LC is unclear. The aim of this study was to evaluate the effects of ERCP on LC and to determine appropriate time of LC after ERCP.MethodsSix hundred twenty-one patients who underwent LC for gallstone disease were enrolled. These patients were divided into two groups; patients with preoperative ERCP prior to LC (ERCP group) and patients who underwent LC without ERCP (non-ERCP group). Among these patients, patients who had shown acute cholecystitis or cholangitis were excluded. To control for different demographic factors in the two groups, propensity score case matching was used at a 1:1 ratio. Finally, 142 patients were matched with 71 patients of the ERCP group and 71 patients of the non-ERCP group. Intraoperative inflammation degree, technical difficulty, and postoperative outcome were analyzed.ResultsIn the ERCP group, the degree of inflammation was severe and operations were more difficult than those of the non-ERCP group. The operation time was longer, and rates of open conversion were higher in the ERCP group. On multivariate analysis, preoperative ERCP was significant factor for difficult operations. The difficulty of operation was not different according to the operation timing after ERCP.ConclusionPreoperative ERCP is a significant factor in difficult LC. Therefore, experienced surgeons should perform LC after preoperative ERCP. Since operation difficulty was similar according to the timing of cholecystectomy after ERCP, there is no reason to delay LC after ERCP.


Journal of The Korean Surgical Society | 2016

Prognostic factors after hepatic resection for the single hepatocellular carcinoma larger than 5 cm

Ji Hyun Noh; Tae-Seok Kim; Keun Soo Ahn; Yong Hoon Kim; Koo Jeong Kang

Purpose This study aimed to determine which factors affect the prognosis of hepatectomy for hepatocellular carcinoma (HCC) larger than 5 cm, including the prognostic difference between tumor sizes from 5–10 cm and larger than 10 cm. Methods The medical records of 114 patients who underwent hepatectomy for single HCC larger than 5 cm were reviewed and analyzed retrospectively. Results In the analysis of the entire cohort of 114 patients, the 5-year overall and diseases-free survival rates were 50% and 29%, respectively. In a comparison of survival rates between groups, tumor sizes of 5 to 10 cm and larger than 10 cm, the overall and disease-free survival rates were not significantly different, respectively (54% vs. 41%, P = 0.433 and 33% vs. 23%, P = 0.083). On multivariate analysis, positive hepatitis B, high prothrombin induced by vitamin K absence or antagonist-II levels over 200 mIU/mL, and vascular invasion (micro- and macrovascular invasion) were independent prognostic factors for recurrence after hepatic resection. However, tumor size larger than 10 cm was not significant for recurrence after resection. Conclusion This study shows that surgical resection of solitary HCC larger than 5 cm showed favorable overall survival. And there is no survival difference with tumors between 5–10 cm and larger than 10 cm.


Journal of Korean Medical Science | 2015

AROS Is a Significant Biomarker for Tumor Aggressiveness in Non-cirrhotic Hepatocellular Carcinoma.

Jung-Hee Kwon; Keun Soo Ahn; Young Ho Moon; Jinyoung Park; Hee Jung Wang; Kwan Yong Choi; Gun-Do Kim; Jae-Won Joh; Kyeong Geun Lee; Koo Jeong Kang

Despite a low risk of liver failure and preserved liver function, non-cirrhotic hepatocellular carcinoma (HCC) has a poor prognosis. In the current study, we evaluated an active regulator of SIRT1 (AROS) as a prognostic biomarker in non-cirrhotic HCC. mRNA levels of AROS were measured in tumor and non-tumor tissues obtained from 283 non-cirrhotic HCC patients. AROS expression was exclusively up-regulated in recurrent tissues from the non-cirrhotic HCC patients (P = 0.015) and also in tumor tissues irrespective of tumor stage (P < 0.001) or BCLC stage (P < 0.001). High mRNA levels of AROS were statistically significantly associated with tumor stage (P < 0.001), BCLC stage (P = 0.007), alpha fetoprotein (AFP) level (P = 0.013), microvascular invasion (P = 0.001), tumor size (P = 0.036), and portal vein invasion (P = 0.005). Kaplan-Meir curve analysis demonstrated that HCC patients with higher AROS levels had shorter disease-free survival (DFS) in both the short-term (P < 0.001) and long-term (P = 0.005) compared to those with low AROS. Cox regression analysis demonstrated that AROS is a significant predictor for DFS along with large tumor size, tumor multiplicity, vascular invasion, and poor tumor differentiation, which are the known prognostic factors. In conclusion, AROS is a significant biomarker for tumor aggressiveness in non-cirrhotic hepatocellular carcinoma.


Clinical and molecular hepatology | 2014

Improved severe hepatopulmonary syndrome after liver transplantation in an adolescent with end-stage liver disease secondary to biliary atresia

Tae Jun Park; Keun Soo Ahn; Yong Hoon Kim; Hyungseop Kim; Ui Jun Park; Hyoung Tae Kim; Won Hyun Cho; Woo-Hyun Park; Koo Jeong Kang

Hepatopulmonary syndrome (HPS) is a serious complication of end-stage liver disease, which is characterized by hypoxia, intrapulmonary vascular dilatation, and liver cirrhosis. Liver transplantation (LT) is the only curative treatment modality for patients with HPS. However, morbidity and mortality after LT, especially in cases of severe HPS, remain high. This case report describes a patient with typical findings of an extracardiac pulmonary arteriovenous shunt on contrast-enhanced transesophageal echocardiography (TEE), and clubbing fingers, who had complete correction of HPS by deceased donor LT. The patient was a 16-year-old female who was born with biliary atresia and underwent porto-enterostomy on the 55th day after birth. She had been suffered from progressive liver failure with dyspnea, clubbing fingers, and cyanosis. Preoperative arterial blood gas analysis revealed severe hypoxia (arterial O2 tension of 54.5 mmHg and O2 saturation of 84.2%). Contrast-enhanced TEE revealed an extracardiac right-to-left shunt, which suggested an intrapulmonary arteriovenous shunt. The patient recovered successfully after LT, not only with respect to physical parameters but also for pychosocial activity, including school performance, during the 30-month follow-up period.

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Ho Seong Han

Seoul National University Bundang Hospital

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In Sang Song

Chungnam National University

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