Academy of Medicine, Singapore clinical guideline on the use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting

INTRODUCTION@#In Singapore, non-anaesthesiologists generally administer sedation during gastrointestinal endoscopy. The drugs used for sedation in hospital endoscopy centres now include propofol in addition to benzodiazepines and opiates. The requirements for peri-procedural monitoring and discharge protocols have also evolved. There is a need to develop an evidence-based clinical guideline on the safe and effective use of sedation by non-anaesthesiologists during gastrointestinal endoscopy in the hospital setting.@*METHODS@#The Academy of Medicine, Singapore appointed an expert workgroup comprising 18 gastroenterologists, general surgeons and anaesthesiologists to develop guidelines on the use of sedation during gastrointestinal endoscopy. The workgroup formulated clinical questions related to different aspects of endoscopic sedation, conducted a relevant literature search, adopted Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology and developed recommendations by consensus using a modified Delphi process.@*RESULTS@#The workgroup made 16 recommendations encompassing 7 areas: (1) purpose of sedation, benefits and disadvantages of sedation during gastrointestinal endoscopy; (2) pre-procedural assessment, preparation and consent taking for sedation; (3) Efficacy and safety of drugs used in sedation; (4) the role of anaesthesiologist administered sedation during gastrointestinal endoscopy; (5) performance of sedation; (6) post-sedation care and discharge after sedation; and (7) training in sedation for gastrointestinal endoscopy for non-anaesthesiologists.@*CONCLUSION@#These recommendations serve to guide clinical practice during sedation for gastrointestinal endoscopy by non-anaesthesiologists in the hospital setting.

Artificial intelligence-assisted colonoscopy: a narrative review of current data and clinical applications

Colonoscopy is the reference standard procedure for the prevention and diagnosis of colorectal cancer, which is a leading cause of cancer-related deaths in Singapore. Artificial intelligence systems are automated, objective and reproducible. Artificial intelligence-assisted colonoscopy has recently been introduced into clinical practice as a clinical decision support tool. This review article provides a summary of the current published data and discusses ongoing research and current clinical applications of artificial intelligence-assisted colonoscopy.

Clinical guidance on endoscopic management of colonic polyps in Singapore

Colonoscopy with endoscopic resection of detected colonic adenomas interrupts the adenoma-carcinoma sequence and reduces the incidence of colorectal cancer and cancer-related mortality. In the past decade, there have been significant developments in instruments and techniques for endoscopic polypectomy. Guidelines have been formulated by various professional bodies in Europe, Japan and the United States, but some of the recommendations differ between the various bodies. An expert professional workgroup under the auspices of the Academy of Medicine, Singapore, was set up to provide guidance on the endoscopic management of colonic polyps in Singapore. A total of 23 recommendations addressed the following issues: accurate description and diagnostic evaluation of detected polyps; techniques to reduce the risk of post-polypectomy bleeding and delayed perforation; the role of specific endoscopic resection techniques; the histopathological criteria for defining endoscopic cure; and the role of surveillance colonoscopy following curative resection.

Academy of Medicine, Singapore clinical guideline on endoscopic surveillance and management of gastric premalignant lesions

Gastric cancer (GC) has a good prognosis, if detected at an early stage. The intestinal subtype of GC follows a stepwise progression to carcinoma, which is treatable with early detection and intervention using high-quality endoscopy. Premalignant lesions and gastric epithelial polyps are commonly encountered in clinical practice. Surveillance of patients with premalignant gastric lesions may aid in early diagnosis of GC, and thus improve chances of survival. An expert professional workgroup was formed to summarise the current evidence and provide recommendations on the management of patients with gastric premalignant lesions in Singapore. Twenty-five recommendations were made to address screening and surveillance, strategies for detection and management of gastric premalignant lesions, management of gastric epithelial polyps, and pathological reporting of gastric premalignant lesions.

Helicobacter pylori Treatment Strategies in Singapore

The management of Helicobacter pylori infection in Singapore remains a clinical challenge. Similar to other regions, there has been an increase in antibiotic resistance rates through the years. Nonetheless, over the past two decades, clarithromycin-based triple therapy has continued to be used as the first line treatment option, with an eradication rate exceeding 90%, although the accepted treatment duration must now be lengthened from 1 to 2 weeks to maintain efficacy. Concomitant and sequential therapies did not demonstrate superiority over standard triple therapy. Current empiric second line treatment utilizes either bismuth-based quadruple therapy or levofloxacin-based triple therapy, but outcomes remain less than ideal. Identifying options to further improve treatment success rates is challenging. Strategies being considered include the use of potent acid suppressants, such as vonoprazan, and H. pylori culture and antibiotic susceptibility testing-guided therapy.

Clinical Features and Predictors of Dysplasia in Proximal Sessile Serrated Lesions

Background/Aims@#Proximal colorectal cancers (CRCs) account for up to half of CRCs. Sessile serrated lesions (SSLs) are precursors to CRC. Proximal location and presence of dysplasia in SSLs predict higher risks of progression to cancer. The prevalence of dysplasia in proximal SSLs (pSSLs) and clinical characteristics of dysplastic pSSLs are not well studied. @*Methods@#Endoscopically resected colonic polyps at our center between January 2016 and December 2017 were screened for pSSLs. Data of patients with at least one pSSL were retrieved and clinicopathological features of pSSLs were analysed. pSSLs with and without dysplasia were compared for associations. @*Results@#Ninety pSSLs were identified, 45 of which had dysplasia giving a prevalence of 50.0%. Older age (65.9 years vs. 60.1 years, p=0.034) was associated with the presence of dysplasia. Twelve pSSLs were 10 mm or larger. After adjusting for age, pSSLs ≥10 mm had an adjusted odds ratio of 5.98 (95% confidence interval, 1.21–29.6) of having dysplasia compared with smaller pSSLs. @*Conclusions@#In our cohort of pSSLs, the prevalence of dysplasia is high at 50.0% and is associated with lesion size ≥10 mm. Endoscopic resection for all proximal serrated lesions should be en-bloc to facilitate accurate histopathological examination for dysplasia as its presence warrants shorter surveillance intervals.

The impact of unrestricted access to direct-acting antiviral among incarcerated hepatitis C virus-infected patients

Background/Aims@#Despite the disproportionally high prevalence rates of hepatitis C virus (HCV) amongst the incarcerated population, eradication remains challenging due to logistic and financial barriers. Although treatment prioritization based on disease severity is commonly practiced, the efficacy of such approach remained uncertain. We aimed to compare the impact of unrestricted access to direct-acting antiviral (DAA) among incarcerated HCV-infected patients in Singapore. @*Methods@#In this retrospective study, we reviewed all incarcerated HCV-infected patients treated in our hospital during the restricted DAA era (2013–2018) and unrestricted DAA access era (2019). Study outcomes included the rate of sustained virological response (SVR), treatment completion and treatment default. Subgroup analysis was performed based on the presence of liver cirrhosis, HCV genotype and HCV treatment types. @*Results@#A total of 1,001 HCV patients was followed-up for 1,489 person-year. They were predominantly male (93%) with genotype-3 HCV infection (71%), and 38% were cirrhotic. The overall SVR during the restricted DAA access era and unrestricted DAA access era were 92.1% and 99.1%, respectively. Unrestricted access to DAA exponentially improved the treatment access among HCV-infected patients by 460%, resulting in a higher SVR rate (99% vs. 92%, P=0.003), higher treatment completion rate (99% vs. 93%, P<0.001) and lower treatment default rate (1% vs. 9%, P<0.001). @*Conclusion@#In this large cohort of incarcerated HCV-infected patients, we demonstrated that unrestricted access to DAA is an impactful strategy to allow rapid treatment up-scale in HCV micro-elimination.

Clinical Features and Predictors of Dysplasia in Proximal Sessile Serrated Lesions

Background/Aims@#Proximal colorectal cancers (CRCs) account for up to half of CRCs. Sessile serrated lesions (SSLs) are precursors to CRC. Proximal location and presence of dysplasia in SSLs predict higher risks of progression to cancer. The prevalence of dysplasia in proximal SSLs (pSSLs) and clinical characteristics of dysplastic pSSLs are not well studied. @*Methods@#Endoscopically resected colonic polyps at our center between January 2016 and December 2017 were screened for pSSLs. Data of patients with at least one pSSL were retrieved and clinicopathological features of pSSLs were analysed. pSSLs with and without dysplasia were compared for associations. @*Results@#Ninety pSSLs were identified, 45 of which had dysplasia giving a prevalence of 50.0%. Older age (65.9 years vs. 60.1 years, p=0.034) was associated with the presence of dysplasia. Twelve pSSLs were 10 mm or larger. After adjusting for age, pSSLs ≥10 mm had an adjusted odds ratio of 5.98 (95% confidence interval, 1.21–29.6) of having dysplasia compared with smaller pSSLs. @*Conclusions@#In our cohort of pSSLs, the prevalence of dysplasia is high at 50.0% and is associated with lesion size ≥10 mm. Endoscopic resection for all proximal serrated lesions should be en-bloc to facilitate accurate histopathological examination for dysplasia as its presence warrants shorter surveillance intervals.

The impact of unrestricted access to direct-acting antiviral among incarcerated hepatitis C virus-infected patients

Background/Aims@#Despite the disproportionally high prevalence rates of hepatitis C virus (HCV) amongst the incarcerated population, eradication remains challenging due to logistic and financial barriers. Although treatment prioritization based on disease severity is commonly practiced, the efficacy of such approach remained uncertain. We aimed to compare the impact of unrestricted access to direct-acting antiviral (DAA) among incarcerated HCV-infected patients in Singapore. @*Methods@#In this retrospective study, we reviewed all incarcerated HCV-infected patients treated in our hospital during the restricted DAA era (2013–2018) and unrestricted DAA access era (2019). Study outcomes included the rate of sustained virological response (SVR), treatment completion and treatment default. Subgroup analysis was performed based on the presence of liver cirrhosis, HCV genotype and HCV treatment types. @*Results@#A total of 1,001 HCV patients was followed-up for 1,489 person-year. They were predominantly male (93%) with genotype-3 HCV infection (71%), and 38% were cirrhotic. The overall SVR during the restricted DAA access era and unrestricted DAA access era were 92.1% and 99.1%, respectively. Unrestricted access to DAA exponentially improved the treatment access among HCV-infected patients by 460%, resulting in a higher SVR rate (99% vs. 92%, P=0.003), higher treatment completion rate (99% vs. 93%, P<0.001) and lower treatment default rate (1% vs. 9%, P<0.001). @*Conclusion@#In this large cohort of incarcerated HCV-infected patients, we demonstrated that unrestricted access to DAA is an impactful strategy to allow rapid treatment up-scale in HCV micro-elimination.

Chapter of Gastroenterologists professional guidance for management of patients with liver disease in Singapore during the COVID-19 pandemic

In this paper, we aim to provide professional guidance to clinicians who are managing patients with chronic liver disease during the current coronavirus disease 2019 (COVID-19) pandemic in Singapore. We reviewed and summarised the available relevant published data on liver disease in COVID-19 and the advisory statements that were issued by major professional bodies, such as the American Association for the Study of Liver Diseases and European Association for the Study of the Liver, contextualising the recommendations to our local situation.

Short- and long-term predictors of spontaneous bacterial peritonitis in Singapore

INTRODUCTION@#Spontaneous bacterial peritonitis (SBP) is the commonest complication of liver cirrhosis. Timely and appropriate treatment of SBP is crucial, particularly with the rising worldwide prevalence of multidrug-resistant organisms (MDROs). We aimed to investigate the clinical outcomes of SBP in Singapore.@*METHODS@#All cirrhotic patients with SBP diagnosed between January 2014 and December 2017 were included. Nosocomial SBP (N-SBP) was defined as SBP diagnosed more than 48 hours after hospitalisation. Clinical outcomes were analysed as categorical outcomes using univariate and multivariate analysis.@*RESULTS@#There were 33 patients with 39 episodes of SBP. Their mean age was 64.5 years and 69.7% were male. The commonest aetiology of cirrhosis was hepatitis B (27.3%). The Median Model for End-stage Liver Disease (MELD) score was 17; 33.3% had acute-on-chronic liver failure and 60.6% had septic shock at presentation. N-SBP occurred in 25.6% of SBP cases. N-SBP was more commonly associated with MDROs, previous antibiotic use in the past three months (p = 0.014) and longer length of stay (p = 0.011). The 30-day and 90-day mortality among SBP patients was 30.8% and 51.3%, respectively. MELD score > 20 was a predictor for 30-day mortality. N-SBP and MELD score > 20 were predictors for 90-day mortality.@*CONCLUSION@#N-SBP was significantly associated with recent antibiotic use, longer hospitalisation, more resistant organisms and poorer survival among patients with SBP. N-SBP and MELD score predict higher mortality in SBP. Judicious use of antibiotics may reduce N-SBP and improve survival among cirrhotic patients.

Chapter of Gastroenterologists professional guidance on risk mitigation for gastrointestinal endoscopy during COVID-19 pandemic in Singapore

In this paper, we aimed to provide professional guidance to practising gastrointestinal (GI) endoscopists for the safe conduct of GI endoscopy procedures during the current coronavirus disease 2019 (COVID-19) pandemic and future outbreaks of similar severe respiratory tract infections in Singapore. It draws on the lessons learnt during the severe acute respiratory syndrome (SARS) epidemic and available published data concerning the COVID-19 pandemic. It addresses measures before, during and after endoscopy that must be considered for both non-infected and infected patients, and provides recommendations for practical implementation.

Effects of proton pump inhibitor on the human gut microbiome profile in multi-ethnic groups in Singapore

INTRODUCTION@#The objectives of this study were to examine the effects of ethnicity, gender and a proton pump inhibitor (PPI), omeprazole, on the human gut microbiome. PPIs are commonly used for the treatment of acid-related disorders. We hypothesised that PPI therapy might perturb microbial communities and alter the gut microbiome.@*METHODS@#Healthy subjects of Chinese (n = 12), Malay (n = 12) and Indian (n = 10) ancestry, aged 21-37 years, were enrolled. They provided a baseline stool sample (Day 1) and were then given a course of omeprazole at therapeutic dose (20 mg daily) for seven days. Stool samples were collected again on Day 7 and 14 (one week after stopping omeprazole). Microbial DNA was extracted from the stool samples, followed by polymerase chain reaction, library construction, 16S rRNA sequencing using Illumina MiSeq, and statistical and bioinformatics analyses.@*RESULTS@#The findings showed an increase in species richness (p = 0.018) after omeprazole consumption on Day 7, which reverted to baseline on Day 14. There were significant increases in the relative abundance of Streptococcus vestibularis (p = 0.0001) and Veillonella dispar (p = 0.0001) on Day 7, which diminished on Day 14. Faecalibacterium prausnitzii, Sutterella stercoricanis and Bacteroides denticanum were characteristic of Chinese, Malays and Indians, respectively. Lactobacillaceae and Bacteroides xylanisolvens were the signature taxa of male and female subjects, respectively.@*CONCLUSION@#The study demonstrated alterations in the gut microbiome following omeprazole treatment. This may explain the underlying pathology of increased risk of Clostridium difficile infections associated with omeprazole therapy.

Safety and efficacy of SpyGlass cholangiopancreatoscopy in routine clinical practice in a regional Singapore hospital

INTRODUCTION@#This study examined the efficacy and safety of cholangiopancreatoscopy via the SpyGlass™ system in routine clinical practice.@*METHODS@#The clinical data of endoscopic retrograde cholangiopancreatography (ERCP) performed in a regional hospital from January 2013 to November 2016 was retrieved from an electronic database and reviewed. All patients who had undergone SpyGlass cholangiopancreatoscopy were enrolled. Patient demographics, procedure indication, technical success rates, clinical success rates and complication rates were analysed. A subanalysis of clinical outcomes was performed comparing the SpyGlass legacy (fibreoptic) and digital systems.@*RESULTS@#Out of 2,050 ERCP procedures performed, 47 patients underwent 50 cholangiopancreatoscopy procedures. Clinical indications were difficult common bile duct (CBD) stones (59.6%, n = 28), indeterminate CBD stricture (36.2%, n = 17), indeterminate pancreatic duct stricture (2.1%, n = 1) and proximally migrated CBD stent (2.1%, n = 1). Complete stone extraction was achieved in 26 (92.9%) out of 28 patients. Among patients with strictures, a correct diagnosis of malignancy based on image visualisation was achieved in all 11 cases. The sensitivity and specificity for SpyBite™ biopsies were 81.8% (95% confidence interval [CI] 48.2%-97.7%) and 100.0% (95% CI 15.8%-100.0%), respectively. The proximally migrated CBD stent was successfully extracted. Complications included pancreatitis (2.1%, n = 1), suspected sealed perforation after laser lithotripsy treated conservatively (2.1%, n = 1) and cholangitis (10.6%, n = 5). There was no difference in clinical outcomes between the SpyGlass legacy (n = 20) and digital (n = 30) systems.@*CONCLUSION@#SpyGlass cholangiopancreatoscopy is a safe and effective tool in routine clinical practice.

Endoscopic submucosal dissection of colorectal neoplasms: an audit of its safety and efficacy in a single tertiary centre in Singapore

INTRODUCTION@#Endoscopic submucosal dissection (ESD) provides a higher en bloc and R0 resection rate than endoscopic mucosal resection. Colorectal ESD is not widely used because of its technical difficulty and risk of complications, especially for right-sided colonic lesions. We audited the clinical outcomes of our initial experience with colorectal ESD.@*METHODS@#We reviewed data collected from a prospective registry of patients who underwent colorectal ESD from December 2014 to March 2018. Therapeutic outcomes and procedure-related complications were analysed.@*RESULTS@#A total of 41 patients (mean age 67.4 years, 21 male) underwent colorectal ESD. The distribution of the lesions was as follows: rectum (n = 9), sigmoid colon (n = 8), descending colon (n = 6), splenic flexure (n = 1), transverse colon (n = 5), ascending colon (n = 8) and caecum (n = 4). The mean size was 23 (range 12-50) mm. En bloc resection was achieved in 35 (85.4%) out of 41 patients, and R0 resection or clear resection margins was achieved in 33 (94.3%) of the en bloc resection patients. The lesion was upstaged in 14 (34.1%) patients after ESD. Colonic perforation occurred in 3 (7.3%) patients during ESD and was successfully treated with endoscopic clips. There was no procedure-related bleeding. No patient required surgery for management of complications. The median duration of hospitalisation was 1 (range 0-7) day. Four patients with lesions that were upstaged after ESD, from high-grade dysplasia to intramucosal carcinoma with deep submucosal invasion, were referred for colectomy.@*CONCLUSION@#Our early outcome data was comparable to that from large published series. ESD is an effective and feasible treatment for colorectal lesions.

Diagnostic Endoscopic Ultrasound: Technique, Current Status and Future Directions

Endoscopic ultrasound (EUS) is now well established as an important tool in clinical practice. From purely diagnostic imaging, it has progressed to include tissue acquisition, which provided the basis for therapeutic procedures. Even as interventional EUS developed, there has been ongoing progress in EUS diagnostic capabilities due to improved imaging systems, better needles for tissue acquisition and development of enhanced imaging functions such as contrast harmonic EUS (CHEUS) and EUS elastography. EUS is well established for differentiation of subepithelial lesions, for T-staging of luminal gastrointestinal and pancreaticobiliary malignancies, for differentiation of benign pancreaticobiliary disorders and for diagnostic tissue acquisition, which can be achieved by EUS-guided fine needle aspiration or by EUS-guided fine needle biopsy using dedicated biopsy needles. This review briefly describes the technique of performing EUS and then discusses its clinical utility in terms of gastrointestinal cancer staging, the evaluation of pancreaticobiliary disorders and tissue acquisition. Enhanced imaging techniques such as CHEUS and EUS elastography are briefly reviewed.

A practical clinical approach to liver fibrosis

Liver fibrosis is a slow, insidious process involving accumulation of extracellular matrix protein in the liver. The stage of liver fibrosis in chronic liver disease (CLD) determines overall morbidity and mortality; the higher the stage, the worse the prognosis. Noninvasive composite scores can be used to determine whether patients with CLD have significant or advanced fibrosis. Patients with low composite scores can be safely followed up in primary care with periodic reassessment. Those with higher scores should be referred to a specialist. As the epidemic of diabetes mellitus, obesity and non-alcoholic fatty liver diseases is rising, CLD is becoming more prevalent. Easy-to-use fibrosis assessment composite scores can identify patients with minimal or advanced fibrosis, and should be an integral part of decision-making. Patients with cirrhosis, high composite scores, chronic hepatitis B with elevated alanine aminotransferase and aspartate aminotransferase, or deranged liver panel of uncertain aetiology should be referred to a specialist.

The diagnosis and management of H. pylori infection in Singapore

Helicobacter pylori (H. pylori) is an infection that has a role in causing dyspepsia and complications such as peptic ulcer disease and gastric malignancies. In the primary care setting, one can adopt a stepwise approach with the 'test-and-treat' strategy to manage H. pylori-associated dyspepsia in young patients without alarm symptoms. Empiric first-line therapies should be for a two-week duration; options include clarithromycin-containing triple therapy alone or with the addition of bismuth, concomitant therapy and bismuth quadruple therapy. Post-treatment carbon urea breath test must be performed at least four weeks after the end of treatment to confirm the cure. Options for empiric second-line treatment include bismuth quadruple therapy and levofloxacin-containing triple therapy. Patients with persistent or alarm symptoms should be referred for further evaluation. Patients with persistent infection should be referred for gastroscopy so that gastric biopsies can be obtained for H. pylori culture and antibiotic susceptibility testing.

Persistent gastro-oesophageal reflux symptoms despite proton pump inhibitor therapy

About one-third of patients with suspected gastro-oesophageal reflux disease (GERD) do not respond symptomatically to proton pump inhibitors (PPIs). Many of these patients do not suffer from GERD, but may have underlying functional heartburn or atypical chest pain. Other causes of failure to respond to PPIs include inadequate acid suppression, non-acid reflux, oesophageal hypersensitivity, oesophageal dysmotility and psychological comorbidities. Functional oesophageal tests can exclude cardiac and structural causes, as well as help to confi rm or exclude GERD. The use of PPIs should only be continued in the presence of acid reflux or oesophageal hypersensitivity for acid reflux-related events that is proven on functional oesophageal tests.

Is endoscopic necrosectomy the way to go?

Pancreatic necrosis with the formation of walled-off collections is a known complication of severe acute pancreatitis. Infected necrotic pancreatic collections are associated with a high mortality rate. Open necrosectomy and debridement with closed drainage has traditionally been the gold standard for treatment of infected pancreatic necrosis, but carries a high risk of perioperative complications. Direct endoscopic necrosectomy has emerged as a safe and effective modality of treatment for this condition. Careful patient selection and gentle meticulous debridement is important to optimize clinical success. Bleeding is the commonest associated complication with the procedure but most cases can be managed conservatively. Air embolism, although rare, is potentially fatal. The use of fully covered large diameter lumen apposing self-expandable metal stents has further simplified the procedure. These stents optimize drainage, and facilitate endoscopic necrosectomy because repeat insertion of the endoscope into the necrotic cavity can be easily achieved.