A retrospective review of correlative radiological assessment and surgical exploration for hilar cholangiocarcinoma

Darren Chua,Albert Low,Yexin Koh,Brian Goh,Peng Chung Cheow,Juinn Har Kam,Jin Yao Teo,Ek Khoon Tan,Alexander Chung,London Lucien Ooi,Chung Yip Chan,Ser Yee Lee 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.3

Backgrounds/Aims: Hilar cholangiocarcinomas (HCCAs) are tumors that involve the biliary confluence; at present, radical surgery offers the only chance of long-term survival, but this can be challenging given the complexity of the hilar anatomy. Blumgart and Jarnagin described a preoperative staging system that incorporates the effect of local tumor extent and its impact on adjacent structures and that has been demonstrated to correlate better with actual surgical resectability. The primary aim of this study is to describe the correlation between preoperative Blumgart-Jarnagin staging and its correlation with surgical resectability. Methods: Patients who underwent surgical resection for hilar cholangiocarcinoma at Singapore General Hospital between January 1, 2002, and January 1, 2013, were identified from a prospectively maintained institutional database. All patients were staged based on the criteria described by Blumgart and Jarnagin. Correlation with surgical resectability was then determined. Results: A total of 19 patients were identified. Overall resectability was 57.8% (n=11). Patients with Blumgart-Jarnagin stage T1 had the highest rates of respectability at 80%; patients with stage T2 and T3 disease had resectability rates of 25% and 40% respectively. Median overall survival was 13.6 months. Conclusions: The Blumgart-Jarnagin staging system is useful for predicting tumor respectability in HCCA.

A single institution experience with robotic and laparoscopic distal pancreatectomies

Shi Qing Lee,Tousif Kabir,Ye-Xin Koh,Jin-Yao Teo,Ser-Yee Lee,Juinn-Huar Kam,Peng-Chung Cheow,Prema Raj Jeyaraj,Pierce K. H. Chow,London L. Ooi,Alexander Y. F. Chung,Chung-Yip Chan,Brian K. P. Goh 한국간담췌외과학회 2020 Annals of hepato-biliary-pancreatic surgery Vol.24 No.3

Backgrounds/Aims: This study aims to describe our experience with minimally-invasive distal pancreatectomies, with emphasis on the comparison between robotic distal pancreatectomy (RDP) and laparoscopic distal pancreatectomy (LDP). Methods: Retrospective review of 102 consecutive RDP and LDP from 2006 to 2019 was performed. Results: There were 27 and 75 patients who underwent RDP and LDP, respectively. There were 12 (11.8%) open conversions and 16 (15.7%) patients had major (>grade 2) morbidities. Patients who underwent RDP had significantly higher rates of splenic preservation (44.4% vs. 13.3%, p=0.002), higher rates of splenic-vessel preservation (40.7% vs. 9.3%, p=0.001), higher median difficulty score (5 vs. 3, p=0.002) but longer operation time (385 vs. 245 minutes, p<0.001). The rate of open conversion tended to be lower with RDP (3.7% vs. 14.7%, p=0.175). Conclusions: In our institution practice, both RDP and LDP were safe and effective. The use of RDP appeared to be complementary to LDP, allowing us to perform more difficult procedures with comparable postoperative outcomes.

Outcome of minimally-invasive versus open pancreatectomies for solid pseudopapillary neoplasms of the pancreas: A 2:1 matched case-control study

Hwee Leong Tan,Ek Khoon Tan,Jin Yao Teo,Juinn Huar Kam,Ser Yee Lee,Peng Chung Cheow,Prema Raj Jeyaraj,Pierce K. Chow,Alexander Y. Chung,London L. Ooi,Chung Yip Chan,Brian K. P. Goh 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.3

Backgrounds/Aims: Solid pseudopapillary neoplasm (SPPN) is typically seen in young healthy females who would likely benefit from minimally-invasive pancreatectomy (MIP). A few comparative studies have suggested that MIP is associated with favorable outcomes when compared to the open approach for SPPN. This study aims to mitigate potential selection bias by performing a matched case-control study comparing MIP vs open pancreatectomy (OP) for SPPN. Methods: We performed a single-institution retrospective electronic chart review of all patients who underwent surgery for pathologically confirmed SPPN between 2000 and 2017. A 2:1 matched comparison using age, gender, tumor size and the type of pancreatectomy was performed between OP and MIP. Results: A total of 40 patients with a median age of 40.3 years (range 16.5-64.4) and female sex predominance (n=34, 85.0%) underwent surgery during the study period. Nine patients underwent MIP. Matched comparison between 18 OP and 9 MIP demonstrated that MIP was associated with a longer median operating time (305 vs 180 min, p=0.046) and shorter median postoperative stay (6 vs 9 days, p=0.015). There were no significant differences in intraoperative blood loss, blood transfusion requirements, postoperative morbidity (including postoperative pancreatic fistula) and mortality, resection margins, lymph node yield and long-term survival. Conclusions: MIP is a safe and viable option in the management of SPPN with the benefit of a shorter postoperative length of stay at the expense of a longer operation time. There was no significant difference in oncologic outcomes between both groups of patients.

Repeat liver resection versus salvage liver transplant for recurrent hepatocellular carcinoma: A propensity score-adjusted and -matched comparison analysis

Yuxin Guo,Ek-Khoon Tan,Nicholas L. Syn,Thinesh-Lee Krishnamoorthy,Chee-Kiat Tan,Reina Lim,Ser-Yee Lee,Chung-Yip Chan,Peng-Chung Cheow,Alexander Y. F. Chung,Prema Raj Jeyaraj,Brian K. P. Goh 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.4

Backgrounds/Aims: Repeat liver resection (RLR) and salvage liver transplantation (SLT) are viable treatment options for recurrent hepatocellular carcinoma (HCC). With possibly superior survival outcomes than RLR, SLT is however, limited by liver graft availability and poses increased perioperative morbidity. In this study, we seek to compare the outcomes of RLR and SLT for patients with recurrent HCC. Methods: Between 1999 and 2018, 94 and 16 consecutive patients who underwent RLR and SLT respectively were identified. Further retrospective subgroup analysis was conducted, comparing 16 RLR with 16 SLT patients via propensity-score matching. Results: After propensity-score adjusted analyses, SLT demonstrated inferior short-term perioperative outcomes than RLR, with increased major morbidity (57.8% vs 5.4 %, p=0.0001), reoperations (39.1% vs 0, p<0.0001), renal insufficiency (30.1% vs 3%, p=0.0071), bleeding (19.8% vs 2.2%, p=0.0289), prolonged intensive care unit stay (median=4 vs 0 days, p<0.0001) and hospital stay (median= 19.8 vs 7.1days, p<0.001). However, SLT showed significantly lower recurrence rate (15.4% versus 70.3%, p=0.0005) and 5-year cumulative incidence of recurrences (19.4% versus 68.4%, p=0.005). Propensity-matched subgroup analysis showed concordant findings. Conclusions: While SLT offers potentially reduced risks of recurrence and trended towards improved long-term survival outcomes relative to RLR, it has poorer short-term perioperative outcomes. Patient selection is prudent amidst organ shortages to maximise allocated resources and optimise patient outcomes.

Predictors of post-hepatectomy liver failure in patients undergoing extensive liver resections for hepatocellular carcinoma

Ken Min Chin,John Carson Allen,Jin Yao Teo,Juinn Huar Kam,Ek Khoon Tan,Yexin Koh,Kim Poh Brian Goh,Peng Chung Cheow,Prema Raj,Kah Hoe Pierce Chow,Yaw Fui Alexander Chung,London Lucien Ooi,Chung Yip Ch 한국간담췌외과학회 2018 Annals of hepato-biliary-pancreatic surgery Vol.22 No.3

Backgrounds/Aims: To determine the prevalence of post-hepatectomy liver failure/insufficiency (PHLF/I) in patients undergoing extensive hepatic resections for hepatocellular carcinoma (HCC) and to assess the predictive value of preoperative factors for post-hepatectomy liver failure or insufficiency (PHLF/I). Methods: A retrospective review of patients who underwent liver resections for HCC between 2001 and 2013 was conducted. Preoperative parameters were assessed and analyzed for their predictive value of PHLF/I. Definitions used included the 50-50, International Study Group of Liver Surgery (ISGLS) and Memorial Sloan Kettering Cancer Centre (MSKCC) criteria. Results: Among the 848 patients who underwent liver resections for HCC between 2001 and 2013, 157 underwent right hepatectomy (RH) and extended right hepatectomy (ERH). The prevalence of PHLF/I was 7%, 41% and 28% based on the 50-50, ISGLS and MSKCC criteria, respectively. There were no significant differences in PHLF/I between RH and ERH. Model for End-Stage Liver Disease (MELD) score and bilirubin were the strongest independent predictors of PHLF/I based on the 50-50 and ISGLS/MSKCC criteria, respectively. Predictive models were developed for each of the criteria with multiple logistic regression. Conclusions: MELD score, bilirubin, alpha-fetoprotein and platelet count showed significant predictive value for PHLF/I (all p<0.05). A composite score based on these factors serves as guideline for physicians to better select patients undergoing extensive resections to minimize PHLF.

Outcomes of salvage liver transplant for recurrent hepatocellular carcinoma

Yuxin Guo,Ek-Khoon Tan,Thinesh-Lee Krishnamoorthy,Chee-Kiat Tan,Ban-Hock Tan,Thuan-Tong Tan,Ser-Yee Lee,Chung-Yip Chan,Peng-Chung Cheow,Alexander Y. F. Chung,Prema Raj Jeyaraj,Brian K. P. Goh 한국간담췌외과학회 2019 Annals of hepato-biliary-pancreatic surgery Vol.23 No.1

Backgrounds/Aims: Salvage liver transplantation (SLT) is a therapeutic strategy for recurrent hepatocellular carcinoma (HCC). However, it remains controversial with compromised survival outcomes and increased perioperative morbidity compared to primary liver transplant (PLT). In the present work, we describe our institution’s experience on SLT by comparing outcomes of SLT to PLT for HCCs. Methods: Retrospective analysis was conducted for 49 transplant patients from 2006-2017. A comparative analysis was carried out between 14 SLT patients and 35 PLT patients. Results: SLT patients demonstrated significantly shorter time to recurrence than PLT patients (median=5.5 versus 23 months, p<0.001) with a trend towards increased perioperative major morbidity (42.9% versus 37%, p=0.711), inferior 5-year overall survival (61% versus 75%, p=0.345) and inferior 5-year recurrence-free survival (57% versus 72%, p=0.263). However, overall survival from the point of primary resection over a 10-year period showed no statistical difference between the 2 groups (SLT=60% versus PLT=61%, p=0.685). Conclusions: SLT is a viable treatment strategy for HCCs. However, it exhibited poorer short-term perioperative and oncologic outcomes than PLT. SLT requires better patient selection with liver donor grafts for optimization of resource allocation in this era of organ shortage. Considering the worldwide shortages in liver grafts, it is hypothesized that optimization of a salvage transplant strategy may improve resource allocation and reap optimal patient outcomes.

Facile synthesis of a 56π-electron 1,2-dihydromethano-[60]PCBM and its application for thermally stable polymer solar cells

Li, Chang-Zhi,Chien, Shang-Chieh,Yip, Hin-Lap,Chueh, Chu-Chen,Chen, Fang-Chung,Matsuo, Yutaka,Nakamura, Eiichi,Jen, Alex K.-Y. Royal Society of Chemistry 2011 Chemical communications Vol.47 No.36

<P>A facile synthesis was employed to make a 56π-electron methano-PC<SUB>61</SUB>BM with a very small 1,2-dihydromethano (CH<SUB>2</SUB>) group. This new fullerene derivative possesses high electron mobility (0.014 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>) and higher LUMO energy level (0.15 eV) than PC<SUB>61</SUB>BM. Bulk hetero-junction devices based on using poly(3-hexylthiophene) and methano-PC<SUB>61</SUB>BM as active layer exhibited better performance and thermal stability than those using the PC<SUB>61</SUB>BM analogue.</P> <P>Graphic Abstract</P><P>We have designed and synthesized a new 56π-electron methano-PC<SUB>61</SUB>BM using a very small and stable 1,2-dihydromethano (CH<SUB>2</SUB>) group. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1cc14446d'> </P>

How to Get into a Good Fellowship?

Ser Yee Lee,Shu Ming, Chai,Chung Yip Chan Korean Society of Gastrointestinal Cancer 2017 Journal of digestive cancer reports Vol.5 No.1

A specialist in the medical field is probably one of the most time-consuming professions to train for before one is considered an expert. Inclusive of medical school, it can take as long as 20 or more years of structured training before one graduates as a new specialist in a particular surgical subspecialty or medical field. A fellowship is often the last official phase in this professional marathon, typically defined as a 1 to 2-year full-on clinical subspecialty experience. One would expect this important "finishing school" to be well researched and written about, however, as compared to other professionals and fields, there is scanty literature on how one can get into a good fellowship program. This is a perspective piece on the intricacies of securing a position in a good fellowship program, drawn from the collective experience of the authors, their colleagues and friends. There are several ways to achieve this and many processes one will encounter. A variety of factors one will need to consider, decide and works towards in this effort of optimizing of their chances of success in getting into their fellowship program of choice. The thought processes, suggestions and solutions at each phase may be helpful. In conclusion, obtaining a choice fellowship position is as much an art as a science, and maybe some luck. Many factors, some more obvious and objective, some softer and more subtle, can all influence the outcome in one way or another.

Improved thin film morphology and bulk-heterojunction solar cell performance through systematic tuning of the surface energy of conjugated polymers

Sun, Ying,Chien, Shang-Chieh,Yip, Hin-Lap,Chen, Kung-Shih,Zhang, Yong,Davies, Joshua A.,Chen, Fang-Chung,Lin, Baoping,Jen, Alex K.-Y. The Royal Society of Chemistry 2012 Journal of materials chemistry Vol.22 No.12

<P>A detailed model study has shown that thin film morphology and bulk-heterojunction solar cell performance can be significantly improved by systematic tuning of the surface energy of the conjugated donor polymer through side-chain functionalization. Thiophene-flanked diketopyrrolopyrrole (DPP) moieties with different contents of cyanohexane side chains were incorporated into three low band-gap conjugated copolymers (<B>PIDTDPP1</B>, <B>PIDTDPP2</B> and <B>PIDTDPP3</B>) consisting of indacenodithiophene (IDT) donors and DPP acceptors. The resulting polymers possessed good solubility in common organic solvents and showed similar energy levels, bandgaps, and hole mobilities. However, the introduction of cyano groups onto the terminal of side-chains significantly changed their surface energy. Topographical images obtained from atomic force microscopy (AFM) proved that a better matched surface energy between polymer and PC<SUB>71</SUB>BM had led to enhanced miscibility, which resulted in better BHJ film morphology. Consistent with the surface energy enhancement, the performance of BHJ photovoltaic devices increased from 0.97% for <B>PIDTDPP1</B>, to 2.16% for <B>PIDTDPP2</B> then to 3.67% for <B>PIDTDPP3</B>. These results clearly reveal that tuning surface energy is an effective way to improve the morphology of the BHJ active layer and efficiency of the photovoltaic device.</P> <P>Graphic Abstract</P><P>We have shown that significantly improved thin film morphology and bulk-heterojunction solar cell performance can be achieved by systematically tuning the surface energy of conjugated polymer donors through side-chain functionalization. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2jm15517f'> </P>

High-mobility low-bandgap conjugated copolymers based on indacenodithiophene and thiadiazolo[3,4-<i>c</i>]pyridine units for thin film transistor and photovoltaic applications

Sun, Ying,Chien, Shang-Chieh,Yip, Hin-Lap,Zhang, Yong,Chen, Kung-Shih,Zeigler, David F.,Chen, Fang-Chung,Lin, Baoping,Jen, Alex K.-Y. Royal Society of Chemistry 2011 Journal of materials chemistry Vol.21 No.35

<P>Two new semiconducting polymers based on indacenodithiophene and thiadiazolo[3,4-<I>c</I>]pyridine units were synthesized <I>via</I> Stille coupling polymerization. The polymers, PIDTPyT and PIDTDTPyT, exhibited main absorption bands in the range of 550–800 nm while their absorption maxima were located at around 700 nm in films. With two additional thiophene spacers, PIDTDTPyT showed a broader absorption band but a 20 nm blue-shifted maximum peak compared to that of PIDTPyT. Both of the polymers possess low bandgaps (∼1.6 eV) and deep energy levels for both the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO). Organic field-effect transistors (OFETs) device measurements indicate that PIDTPyT and PIDTDTPyT have high hole carrier mobilities of 0.066 and 0.045 cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, respectively, with the on/off ratio on the order of 10<SUP>6</SUP>. Bulk heterojunction photovoltaic devices consisting of the copolymers and PC<SUB>71</SUB>BM gave power conversion efficiencies (PCE) as high as 3.91% with broadband photo-response in the range of 300–800 nm. The relationships between the photovoltaic performance and film morphology, energy levels, hole mobilities are discussed.</P> <P>Graphic Abstract</P><P>Low bandgap regiorandom polymers based on indacenodithiophene and thiadiazolo[3,4-<I>c</I>]pyridine units showed excellent OFET hole mobilities and promising photovoltaic device performance as high as 3.91%. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c1jm11564b'> </P>