Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Gi Won Song is active.

Publication


Featured researches published by Gi Won Song.


Liver Transplantation | 2006

Lessons learned from 1,000 living donor liver transplantations in a single center: how to make living donations safe.

Shin Hwang; Sung-Gyu Lee; Young-Joo Lee; Kyu Bo Sung; Kwang Min Park; Ki Hun Kim; Chul Soo Ahn; Deok Bog Moon; Gyu Sam Hwang; Kyung Mo Kim; Tae Yong Ha; Dong Sik Kim; Jae Pil Jung; Gi Won Song

Serious complications have occurred in a considerable proportion of living donors of liver transplants, but data from a single high‐volume center has rarely been available. We analyzed the medical records of donors and recipients of the first 1,000 living donor liver transplants, performed at Asan Medical Center from December 1994 to June 2005, with a focus on donor safety. There were 107 pediatric and 893 adult transplants. The most common diagnoses were biliary atresia in pediatric recipients (63%) and hepatitis B‐associated liver cirrhosis (80%) in adult recipients. Right lobe donors were strictly selected based on liver resection rate and steatosis. From 1,162 living donors, 588 right lobes, 6 extended right lobes, 7 right posterior segments, 464 left lobes, and 107 left lateral segments were obtained. Of these, 837 grafts were implanted singly, whereas 325, along with 1 cadaveric split graft, were implanted as dual grafts into 163 recipients. The 5‐yr survival rates were 84.8% in pediatric recipients and 83.2% in adult recipients. There was no donor mortality, but 3.2% of donors experienced major complications. Until the end of 2001, the major donor complication rate was 6.7%, with most occurring in right liver donors. Since 2002, liver resection exceeding 65% of whole liver volume were avoided except for young donors with no hepatic steatosis, and the donor complication rate has been reduced to 1.3%. In conclusion, a majority of major living donor complications appear to be avoidable through the strict selection of living donor and graft type, intensive postoperative surveillance, and timely feedback of surgical techniques. Selection of right lobe graft should be very prudently considered if the donor right liver appears to be larger than 65% of the whole liver volume. Liver Transpl 12:920–927, 2006.


Liver Transplantation | 2006

Long‐term incidence, risk factors, and management of biliary complications after adult living donor liver transplantation

Shin Hwang; Sung-Gyu Lee; Kyu Bo Sung; Kwang Min Park; Ki Hun Kim; Chul Soo Ahn; Young-Joo Lee; Sung Koo Lee; Gyu Sam Hwang; Deok Bog Moon; Tae Yong Ha; Dong Sik Kim; Jae Pil Jung; Gi Won Song

A considerable proportion of adult living donor liver transplantation (LDLT) recipients experience biliary complication (BC), but there are few reports regarding BC based on long‐term studies of a large LDLT population. The present study examined BC incidence, risk factors and management using single‐center data from 259 adult patients (225 right liver and 34 left liver grafts) between 2000 and 2002. The mean follow‐up period was 46 ± 14 months. Biliary reconstruction included single duct‐to‐duct anastomosis (DD, n = 141), double DD (n = 19), single hepaticojejunostomy (HJ, n = 67), double HJ (n = 28), and combined DD and HJ (n = 4). There were 12 episodes of anastomotic bile leak and 42 episodes of anastomotic stenosis in 50 recipients. Most leaks occurred within the first month, whereas stenosis occurred over 3 yr. Most stenoses were successfully treated using radiological intervention. Cumulative 1‐, 3‐, and 5‐yr BC rates were 12.9%, 18.2%, and 20.2%, respectively. BC occurred much more frequently in right liver grafts compared to left liver grafts (P = 0.024). Stenosis‐free survival curves for right liver graft recipients were similar for all reconstruction groups. When right liver graft recipients with single biliary reconstructions were grouped according to graft duct size and type of biliary reconstruction, DD involving a small‐sized duct (less than 4 mm in diameter) was found to be a BC risk factor (P = 0.015), whereas HJ involving such duct sizes was not found to be associated with a higher risk (P = 0.471). In conclusion, close surveillance for BC appears necessary for at least the first 3 yr after LDLT. We found that most BC could be successfully controlled using radiological intervention. In terms of anastomotic stenosis risk, HJ appears a better choice than DD for right liver grafts involving ducts less than 4 mm in diameter. Liver Transpl 12:831–838, 2006.


Journal of Hepato-biliary-pancreatic Sciences | 2010

Surgical treatment of hilar cholangiocarcinoma in the new era: the Asan experience

Sung-Gyu Lee; Gi Won Song; Shin Hwang; Tae Yong Ha; Deok Bog Moon; Dong Hwan Jung; Ki Hun Kim; Chul Soo Ahn; Myung-Hwan Kim; Sung Koo Lee; Kyu Bo Sung; Gi Young Ko

Background/purposeBoth curative resection and minimized in-hospital mortality offer the only chance of long-term survival in patients with hilar cholangiocarcinoma. The reported resectability rates for hilar cholangiocarcinoma have increased by virtue of combined major hepatectomy, but this procedure is technically demanding and still associated with a significant morbidity and mortality that must be carefully balanced against the chances of long-term survival.MethodsBetween January 2001 and December 2008, 350 patients with hilar cholangiocarcinoma underwent exploration for the purpose of potentially curative resection, of whom 302 (86.3%) were resected in the Department of Hepato-Biliary Surgery and Liver Transplantation, Asan Medical Center, University of Ulsan College of Medicine. Combined hepatectomy was carried out in 268 (88.7%) of 302 resected patients. Major hemihepatectomy and parenchyma-preserving hepatectomy were performed in 257 and 11 patients, respectively. Portal vein resection was associated in 40 (14.9%) of 268 hepatectomized patients. To control preoperative cholangitis and reduce risk of postoperative hepatic failure, biliary decompression through endoscopic and/or percutaneous transhepatic drainage and portal vein embolization were preoperatively applied in 329 (94.0%) of 350 explored patients and in 91 (54.2%) of 168 extended hepatectomized patients (154 right hemihepatectomy, 9 right trisectionectomy, 5 left trisectionectomy), respectively. Liver transplantation was not performed as primary treatment for hilar cholangiocarcinoma.ResultsThere were 5 cases (1.7%) of in-hospital death after resection and 1 postoperative liver failure that was successfully treated with liver transplantation. Major complications were encountered in 23 patients (7.0%), and the overall morbidity rate was 43%. In 302 resections, 214 (70.9%) were curative resections (R0) and 88 (29.1%) were palliative resections (R1). The overall 1-, 3- and 5-year survival rates after resection, including in-hospital deaths, were 84.6, 50.7 and 47.3% in the R0 group and 69.9, 33.3 and 7.5% in the R1 group, respectively. The 5-year survival rate of extended hemihepatectomy of 36.4% was better than that of parenchyma-preserving hepatectomy at 10.5%. Two significant predictive factors adversely affecting survival after resection were lymph node metastasis and incurability of surgery (Pxa0<xa00.001). Two patients with vascular involvement who underwent concomitant hepatic artery and portal vein reconstruction are alive after more than 3xa0years.ConclusionPreoperative biliary decompression and portal vein embolization enabled us to reduce in-hospital deaths associated with extended hepatectomy for hilar cholangiocarcinoma. Major hemihepatectomy offers an increased survival because of the higher possibility of curative resection than bile duct resection alone and parenchyma-preserving hepatectomy, but it still carries a certain mortality. Less extensive procedures can be conducted safely and are beneficial for aged patients in poor condition with a less advanced tumor stage if tumor-free resectional margins are obtained.


Annals of Surgical Oncology | 2009

Surgical treatments and prognoses of patients with combined hepatocellular carcinoma and cholangiocarcinoma.

Ki Hun Kim; Sung-Gyu Lee; Eun Hwa Park; Shin Hwang; Chul Soo Ahn; Deok Bog Moon; Tae Yong Ha; Gi Won Song; Dong Hwan Jung; Kang Mo Kim; Young Suk Lim; Han Chu Lee; Young Hwa Chung; Yung Sang Lee; Dong Jin Suh

BackgroundCombined hepatocellular carcinoma and cholangiocarcinoma is a very rare form of primary liver cancer containing components of both tumor types. We evaluated the effectiveness of surgical treatment and factors related to survival and recurrence.Patients and MethodsOf the 2427 patients who underwent hepatectomy or liver transplantation because of a primary hepatic malignancy from January 1989 to July 2006 at the Asan Medical Center, Seoul, Korea, 29 had hepatocellular carcinoma and cholangiocarcinoma as a single mixed or transitional tumor. Their medical records were retrospectively reviewed.ResultsDisease-free survival rates at 6xa0months, 1xa0year, and 3xa0years were 51.1%, 38.3%, and 25.6%, respectively. Univariate analysis showed that CA 19–9 above 37xa0U/ml was predictive of low overall survival (Pxa0=xa0.03) and that TNM stage was significantly associated with disease-free survival (Pxa0=xa0.04).ConclusionsPatients with combined hepatocellular carcinoma and cholangiocarcinoma had poor postoperative survival rates. High CA 19–9 level was associated with poorer survival, suggesting that the cholangiocarcinoma portion may be a major determining factor for patient prognosis. Aggressive surgical treatment, including lymph node dissection, may improve survival in patients suspected of or diagnosed with these tumors.


Radiology | 2011

Hepatic Arterial Stenosis Assessed with Doppler US after Liver Transplantation: Frequent False-Positive Diagnoses with Tardus Parvus Waveform and Value of Adding Optimal Peak Systolic Velocity Cutoff

Yang Shin Park; Kyoung Won Kim; So Jung Lee; Jeongjin Lee; Dong Hwan Jung; Gi Won Song; Tae Yong Ha; Deok Bog Moon; Ki Hun Kim; Chul Soo Ahn; Shin Hwang; Sung-Gyu Lee

PURPOSEnTo evaluate the utility of the tardus parvus waveform of the hepatic artery at Doppler ultrasonography (US) in the diagnosis of hepatic arterial stenosis in liver transplant (LT) recipients and determine whether the accuracy of such a diagnosis is enhanced by including an optimal peak systolic velocity (PSV) cutoff.nnnMATERIALS AND METHODSnThis retrospective study was institutional review board approved; the requirement for informed consent was waived. The authors identified 361 LT recipients (267 male, 94 female) who underwent Doppler US and either computed tomography (CT) or angiography, with an interval between these examinations of less than 1 week. At Doppler US, tardus parvus pattern was defined as a waveform with a resistive index (RI) of less than 0.5 and a systolic acceleration time longer than 0.08 second. At CT or angiography, patients were assigned to the hepatic arterial stenosis (≥50% vessel narrowing) or nonstenosis group. The capability of the tardus parvus pattern to facilitate the diagnosis of hepatic arterial stenosis was calculated. The difference in PSV between the true- and false-positive tardus parvus patterns was evaluated. Receiver operating characteristic (ROC) analysis was performed to determine the optimal cutoff PSV for diagnosing hepatic arterial stenosis. The capability of the tardus parvus pattern and an optimal PSV cutoff in the diagnosis of hepatic arterial stenosis was determined.nnnRESULTSnSixty transplant recipients had the tardus parvus pattern at Doppler US. The sensitivity, specificity, and positive predictive value (PPV) of the tardus parvus pattern were 72% (23 of 32 LT recipients), 88.8% (292 of 329 LT recipients), and 38% (23 of 60 LT recipients), respectively. The false-positive rate was 11.2% (37 of 329 LT recipients). ROC analysis revealed an optimal PSV cutoff of less than or equal to 48 cm/sec for diagnosing hepatic arterial stenosis. The combination of the tardus parvus pattern and a PSV cutoff of less than or equal to 48 cm/sec improved specificity to 99.1% (326 of 329 LT recipients) and the PPV to 88% (22 of 25 LT recipients), thereby reducing the false-positive rate to 1% (three of 329 LT recipients) while slightly decreasing the sensitivity to 69% (22 of 32 LT recipients).nnnCONCLUSIONnUse of the tardus parvus waveform of the hepatic artery resulted in a low PPV and a high false-positive rate. However, the combination of the tardus parvus pattern and an optimal PSV cutoff greatly improved the PPV and reduced the false-positive rate in the diagnosis of hepatic arterial stenosis.


Clinical Transplantation | 2007

Neurologic complications in adult living donor liver transplant recipients

Bum Soo Kim; Sung-Gyu Lee; Shin Hwang; Kwang Min Park; Ki Hun Kim; Chul Soo Ahn; Deok Bog Moon; Tae Yong Ha; Gi Won Song; Dong Sik Kim; Ki Myung Moon; Dong Hwan Jung

Abstract:u2002 Background:u2002 Neurologic complications (NC) after liver transplantation are not uncommon, with serious complications such as central pontine myelinolysis (CPM), often causing disability.


Journal of Hepato-biliary-pancreatic Sciences | 2010

Liver transplantation for hepatocellular carcinoma: Korean experience

Sung-Gyu Lee; Chul Soo Ahn; Tae Yong Ha; Deok Bog Moon; Kun Moo Choi; Gi Won Song; Dong Hwan Chung; Gil Chun Park; Young Dong Yu; Nam Kyu Choi; Kwan Woo Kim; Ki Hun Kim; Shin Hwang

Hepatocellular carcinoma (HCC) is the second most common cause of male cancer death in Korea, where the major etiology, chronic hepatitis B virus infection, is endemic. With a high incidence of unresectable HCCs and a low cadaveric organ donation rate, the number of adult living-donor liver transplantations (LDLTs) has increased rapidly, by tenfold, over the past 10xa0years, as an alternative to deceased-donor liver transplantation (DDLT) in Asia, including Korea. Currently, HCC accounts for more than 40% of the indications for adult LDLT as the associated decompensation cirrhosis or unresectable HCC with 2.8% perioperative mortality at our institute. In determining eligibility for LDLT, the Milan criteria, which have a major aim of reducing the wastage of cadaveric liver grafts, still remain the gold standard. Our published results with 168 adult LDLTs show no difference from the results with DDLT for HCC that meets the Milan criteria. However, since a substantial proportion of adult LDLT patients not fulfilling the Milan criteria have been found to survive for longer than expected, and because a live donor organ is a private gift, most LDLT programs in Korea accept HCC patients beyond the Milan criteria, and the reported 3-year survival rates for such patients are approximately 63%. Our new proposal for expanded criteria (Asan criteria; tumor diameter ≤5xa0cm, number of lesions ≤6, no gross vascular invasion) in LDLT has focused on extending the number limits but keeping the maximum tumor size at 5xa0cm, because even modest expansion of tumor size limits beyond the Milan criteria adversely affected survival. The overall 5-year patient survival rates were 76.3 and only 18.9% within and beyond the Asan criteria, respectively; these criteria broaden the indications for patient selection and can more accurately identify patients who will benefit from LDLT than the conventional Milan criteria and the University of California at San Francisco criteria. In Asia, where the option for DDLT is minimal or negligible, LDLT with the modest expanded selection criteria will continue to provide a chance of long-term survival for some patients with advanced HCC.


Journal of Gastrointestinal Surgery | 2011

Super-selection of a Subgroup of Hepatocellular Carcinoma Patients at Minimal Risk of Recurrence for Liver Transplantation

Shin Hwang; Chul Soo Ahn; Ki Hun Kim; Deok Bog Moon; Tae Yong Ha; Gi Won Song; Dong Hwan Jung; Gil Chun Park; Young Dong Yu; Pyoung Jae Park; Young Il Choi; Kyoung Won Kim; Young Suk Lim; Han Chu Lee; Eun Sil Yu; Sung-Gyu Lee

BackgroundA majority of patients with hepatocellular carcinoma (HCC) undergoing liver transplantation (LT) meet the Milan criteria, but these are still regarded as the narrowest criteria for transplantation. Prognostic analysis of incidentally detected HCC after LT suggests that a subgroup of HCC patients is at very low risk of recurrence. To determine the criteria defining this super-selection group, we retrospectively analyzed survival data of 593 adult living-donor LT recipients with HCC in the explanted liverDiscussionTumor features of incidental HCC in 38 patients not showing recurrence were analyzed. Of these patients, 34 (89.5%) each had ≤2 tumors and tumors ≤2.0xa0cm in size. Applying these criteria to 555 patients with pretransplant known HCC (pkHCC) allowed us to identify 79 patients with untreated pkHCCs ≤2.0xa0cm in size. To date, only two of these patients have shown recurrence, making the conditions for super-selection the presence of tumors ≤2.0xa0cm in size, ≤2 tumors, alpha-fetoprotein ≤200xa0ng/mL, and no pretransplant treatment. In 87 patients satisfying these criteria, the 10-year recurrence and survival rates were 1.3% and 92.1%, respectively. After excluding patients meeting these criteria, the 5-year recurrence rates in patients satisfying the Milan, University of California at San Francisco, and Asan criteria were increased by 2.9–4.0%. In conclusion, this super-selection or super-Milan category may be used for validation assessment of various indication criteria and for the development of cost-effective post-transplantation HCC surveillance protocols. Further studies should be followed for deceased-donor LT and patients who have undergone pretransplant treatment.


Liver Transplantation | 2010

Exchange living donor liver transplantation to overcome ABO incompatibility in adult patients

Shin Hwang; Sung-Gyu Lee; Deok Bog Moon; Gi Won Song; Chul Soo Ahn; Ki Hun Kim; Tae Yong Ha; Dong Hwan Jung; Kwan Woo Kim; Nam Kyu Choi; Gil Chun Park; Young Dong Yu; Young Il Choi; Pyoung Jae Park; Hea Seon Ha

ABO incompatibility is the most common cause of donor rejection during the initial screening of adult patients with end‐stage liver disease for living donor liver transplantation (LDLT). A paired donor exchange program was initiated to cope with this problem without ABO‐incompatible LDLT. We present our results from the first 6 years of this exchange adult LDLT program. Between July 2003 and June 2009, 1351 adult LDLT procedures, including 16 donor exchanges and 7 ABO‐incompatible LDLT procedures, were performed at our institution. Initial donor‐recipient ABO incompatibilities included 6 A to B incompatibilities, 6 B to A incompatibilities, 1 A to O incompatibility, 1 A+O (dual graft) to B incompatibility, 1 O to AB incompatibility, and 1 O to A incompatibility. Fourteen matches (87.5%) were ABO‐incompatible, but 2 (12.5%) were initially ABO‐compatible. All ABO‐incompatible donors were directly related to their recipients, but 2 compatible donors were each undirected and unrelated directed. After donor reassignment through paired exchange (n = 7) or domino pairing (n = 1), the donor‐recipient ABO status changed to A to A in 6, B to B in 6, O to O in 1, A to AB in 1, A+O to A in 1, and O to B in 1, and this made all matches ABO‐identical (n = 13) or ABO‐compatible (n = 3). Two pairs of LDLT operations were performed simultaneously on an elective basis in 12 and on an emergency basis in 4. All donors recovered uneventfully. Fifteen of the 16 recipients survived, but 1 died after 54 days. In conclusion, an exchange donor program for adult LDLT appears to be a feasible modality for overcoming donor‐recipient ABO incompatibility. Liver Transpl , 2010.


Annals of Surgery | 2016

Defining Benchmarks for Major Liver Surgery: A multicenter Analysis of 5202 Living Liver Donors.

Fabian Rössler; Gonzalo Sapisochin; Gi Won Song; Yu Hung Lin; Mary Ann Simpson; Kiyoshi Hasegawa; Andrea Laurenzi; Santiago Sánchez Cabús; Milton Inostroza Nunez; Andrea Gatti; Magali Chahdi Beltrame; Ksenija Slankamenac; Paul D. Greig; Sung-Gyu Lee; Chao Long Chen; David R. Grant; Elizabeth A. Pomfret; Norihiro Kokudo; Daniel Cherqui; Kim M. Olthoff; Abraham Shaked; Juan Carlos García-Valdecasas; Jan Lerut; Roberto Troisi; Martin de Santibañes; Henrik Petrowsky; Milo A. Puhan; Pierre-Alain Clavien

Objective: To measure and define the best achievable outcome after major hepatectomy. Background: No reference values are available on outcomes after major hepatectomies. Analysis in living liver donors, with safety as the highest priority, offers the opportunity to define outcome benchmarks as the best possible results. Methods: Outcome analyses of 5202 hemi-hepatectomies from living donors (LDs) from 12 high-volume centers worldwide were performed for a 10-year period. Endpoints, calculated at discharge, 3 and 6 months postoperatively, included postoperative morbidity measured by the Clavien-Dindo classification, the Comprehensive Complication Index (CCI), and liver failure according to different definitions. Benchmark values were defined as the 75th percentile of median morbidity values to represent the best achievable results at 3 month postoperatively. Results: Patients were young (34 ± [9] years), predominantly male (65%) and healthy. Surgery lasted 7 ± [2] hours; 2% needed blood transfusions. Mean hospital stay was 11.7± [5] days. 12% of patients developed at least 1 complication, of which 3.8% were major events (≥grade III, including 1 death), mostly related to biliary/bleeding events, and were twice higher after right hepatectomy. The incidence of postoperative liver failure was low. Within 3-month follow-up, benchmark values for overall complication were ⩽31 %, for minor/major complications ⩽23% and ⩽9%, respectively, and a CCI ⩽33 in LDs with complications. Centers having performed ≥100 hepatectomies had significantly lower rates for overall (10.2% vs 35.9%, P < 0.001) and major (3% vs 12.1%, P < 0.001) complications and overall CCI (2.1 vs 8.5, P < 0.001). Conclusions: The thorough outcome analysis of healthy LDs may serve as a reference for evaluating surgical performance in patients undergoing major liver resection across centers and different patient populations. Further benchmark studies are needed to develop risk-adjusted comparisons of surgical outcomes.

Collaboration


Dive into the Gi Won Song's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge