Christopher Khor

Dr. Christopher Khor


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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30 July 2023 in Clinical Endoscopy
Verified
Journal Article
Open access
PDF file
CWClement Wu
Clement Wu
SLSamuel Jun Ming Lim
Samuel Jun Ming Lim
CKChristopher Khor
Christopher Khor
Endoscopic retrograde cholangiopancreatography (ERCP) plays a crucial role in the management of pancreaticobiliary disorders. Although the ERCP technique has been refined over the past five decades, it remains one of the endoscopic procedures with the highest rate of complications. Risk factors for ERCP-related complications are broadly classified into patient-, procedure-, and operator-related risk factors. Although non-modifiable, patient-related risk factors allow for the closer monitoring and instatement of preventive measures. Post-ERCP pancreatitis is the most common complication of ERCP. Risk reduction strategies include intravenous hydration, rectal nonsteroidal anti-inflammatory drugs, and pancreatic stent placement in selected patients. Perforation is associated with significant morbidity and mortality, and prompt recognition and treatment of ERCP-related perforations are key to ensuring good clinical outcomes. Endoscopy plays an expanding role in the treatment of perforations. Specific management strategies depend on the location of the perforation and the patient’s clinical status. The risk of post-ERCP bleeding can be attenuated by preprocedural optimization and adoption of intra-procedural techniques. Endoscopic measures are the mainstay of management for post-ERCP bleeding. Escalation to angioembolization or surgery may be required for refractory bleeding. Post-ERCP cholangitis can be reduced with antibiotic prophylaxis in high risk patients. Bile culture-directed therapy plays an important role in antimicrobial treatment.

14 January 2020 in Gut
Verified
Journal Article
Open access
PDF file
VKVaidehi Krishnan
Vaidehi Krishnan
DLDebbie Xiu En Lim
Debbie Xiu En Lim
PHPhuong Mai Hoang
Phuong Mai Hoang
SSSupriya Srivastava
Supriya Srivastava
JMJunichi Matsuo
Junichi Matsuo
Yoshiaki ItoYoshiaki Ito
Yoshiaki Ito
Objective: Intestinal metaplasia (IM) is a premalignant stage that poses a greater risk for subsequent gastric cancer (GC). However, factors regulating IM to GC progression remain unclear. Previously, activated DNA damage response (DDR) signalling factors were shown to engage tumour-suppressive networks in premalignant lesions. Here, we interrogate the relationship of DDR signalling to mutational accumulation in IM lesions.Design: IM biopsies were procured from the gastric cancer epidemiology programme, an endoscopic surveillance programme where biopsies have been subjected to (epi)genomic characterisation. IM samples were classified as genome-stable or genome-unstable based on their mutational burden/somatic copy-number alteration (CNA) profiles. Samples were probed for DDR signalling and cell proliferation, using the markers γH2AX and MCM2, respectively. The expression of the gastric stem cell marker, CD44v9, was also assessed. Tissue microarrays representing the GC progression spectrum were included.Results: MCM2-positivity increased during GC progression, while γH2AX-positivity showed modest increase from normal to gastritis and IM stages, with further increase in GC. γH2AX levels correlated with the extent of chronic inflammation. Interestingly, genome-stable IM lesions had higher γH2AX levels underscoring a protective anti-cancer role for DDR signalling. In contrast, genome-unstable IM lesions with higher mutational burden/CNAs had lower γH2AX levels, elevated CD44v9 expression and modest promoter hypermethylation of DNA repair genesWRN, MLH1andRAD52.Conclusions: Our data suggest that IM lesions with active DDR will likely experience a longer latency at the premalignant state until additional hits that override DDR signalling clonally expand and promote progression. These observations provide insights on the factors governing IM progression.

21 February 2012 in Surgical Endoscopy
Verified
Journal Article
Closed access
PDF file
WRWiriyaporn Ridtitid
Wiriyaporn Ridtitid
RRRungsun Rerknimitr
Rungsun Rerknimitr
STSombat Treeprasertsuk
Sombat Treeprasertsuk
PKPradermchai Kongkam
Pradermchai Kongkam
CKChristopher Khor
Christopher Khor
PKPinit Kullavanijaya
Pinit Kullavanijaya

3 September 2024 in Gut and Liver
Verified
Journal Article
Open access
PDF file
SKSeung Joo Kang
Seung Joo Kang
CTChung Hyun Tae
Chung Hyun Tae
Chang Seok BangChang Seok Bang
Chang Seok Bang
CSCheol Min Shin
Cheol Min Shin
YJYoung-Hoon Jeong
Young-Hoon Jeong
TGThe Korean Society Of Gastrointestinal Endoscopy Task Force On Clinical Practice Guidelines
The Korean Society Of Gastrointestinal Endoscopy Task Force On Clinical Practice Guidelines
Seung Joo Kang, Chung Hyun Tae, Chang Seok Bang, Cheol Min Shin, Young-Hoon Jeong, Miyoung Choi, Joo Ha Hwang, Yutaka Saito, Philip Wai Yan Chiu, Rungsun Rerknimitr, Christopher Khor, Vu Van Khien, Kee Don Choi, Ki-Nam Shim, Geun Am Song, Oh Young Lee, the Korean Society of Gastrointestinal Endoscopy Task Force on Clinical Practice Guidelines. Gut and Liver 2024;18:764-80. https://doi.org/10.5009/gnl240176

30 March 2024 in Clinical Endoscopy
Verified
Journal Article
Open access
PDF file
SKSeung Joo Kang
Seung Joo Kang
CTChung Hyun Tae
Chung Hyun Tae
Chang Seok BangChang Seok Bang
Chang Seok Bang
CSCheol Min Shin
Cheol Min Shin
YJYoung-Hoon Jeong
Young-Hoon Jeong
YLYong Chan Lee
Yong Chan Lee
Antithrombotic agents, including antiplatelet agents and anticoagulants, are widely used in Korea because of the increasing incidence of cardiocerebrovascular disease and the aging population. The management of patients using antithrombotic agents during endoscopic procedures is an important clinical challenge. The clinical practice guidelines for this issue, developed by the Korean Society of Gastrointestinal Endoscopy, were published in 2020. However, new evidence on the use of dual antiplatelet therapy and direct anticoagulant management has emerged, and revised guidelines have been issued in the United States and Europe. Accordingly, the previous guidelines were revised. Cardiologists were part of the group that developed the guideline, and the recommendations went through a consensus-reaching process among international experts. This guideline presents 14 recommendations made based on the Grading of Recommendations, Assessment, Development, and Evaluation methodology and was reviewed by multidisciplinary experts. These guidelines provide useful information that can assist endoscopists in the management of patients receiving antithrombotic agents who require diagnostic and elective therapeutic endoscopy. It will be revised as necessary to cover changes in technology, evidence, or other aspects of clinical practice.

17 May 2024 in Medicine
Verified
Journal Article
Open access
JKJonathan T.E. Mbbs Koh
Jonathan T.E. Mbbs Koh
KLKim wei Lim
Kim wei Lim
CFCarlos Paolo Francisco
Carlos Paolo Francisco
RRRajesh R
Rajesh R
WCWebber Mbbs Chan
Webber Mbbs Chan
RARavishankar Mbbs Asokkumar
Ravishankar Mbbs Asokkumar
Device assisted enteroscopy (DAE) like the double balloon enteroscopy (DBE) and single balloon enteroscopy (SBE) are postulated to ease small bowel examination and performance of therapy. However, studies comparing the effectiveness of these 2 modalities have yielded varying results. The aim of this study is to compare the efficacy and safety of SBE and DBE. We retrospectively reviewed records of patients who underwent DBE (n = 82) or SBE (n = 45) for small bowel exam in our unit from January 2014 to January 2022. Our primary outcomes were to compare the technical success and diagnostic success rates between DBE and SBE. Our secondary outcomes were to compare the therapeutic success, and complication rates. The main indications were suspected GI bleeding (DBE 41.5% vs SBE 48.9%), iron deficiency anemia (DBE 9.8% vs SBE 4.4%) and small bowel lesions (DBE 28.0% vs SBE 44.4%) detected either from prior capsule endoscopy or radiological imaging. Majority of the enteroscopy exam was by antegrade approach (DBE 67.1% vs SBE 77.8%). We found no significant difference in the technical success (DBE 95.1% vs SBE 97.8%, P = .46), diagnostic success (DBE 69.5% vs SBE 77.8%, P = .36) and the therapeutic success rate (DBE 63.2% vs SBE 54.3%, P = .09) between the groups. Complications occurred in 1 case from each group (mucosal tear). None of the complications were major. In patients who underwent enteroscopy, the diagnostic and therapeutic performance of SBE is similar to DBE. Both procedures were safe with low complication rates.