Andrew Kwek

An analysis of the efficacy and safety of a strategy of early precut for biliary access during difficult endoscopic retrograde cholangiopancreatography in a general hospital.

OBJECTIVE:  The use of early precut during endoscopic retrograde cholangiopancreatography (ERCP) is controversial because of its association with a higher risk of complications. This study examined the efficacy and safety of a strategy of early precut for biliary access during difficult ERCP in a general hospital.

A two-center comparative study of plastic and lumen-apposing large diameter self-expandable metallic stents in endoscopic ultrasound-guided drainage of pancreatic fluid collections

Background and Objectives: Endoscopic ultrasound-guided drainage of walled-off pancreatic fluid collections (PFCs) (pseudocyst [PC]; walled-off necrosis [WON]) utilizes double pigtail plastic stents (PS) and the newer large diameter fully covered self-expandable stents (FCSEMS) customized for PFC drainage. This study examined the impact of type of stent on clinical outcomes and costs. Patients and Methods: Retrospective two-center study. Outcome variables were technical and clinical success, need for repeat procedures, need for direct endoscopic necrosectomy (DEN), and procedure-related costs. Results: A total of 49 (PC: 31, WON: 18) patients were analyzed. Initially, PS was used in 37 and FCSEMS in 12. Repeat transmural drainage was required in 14 (PS: 13 [9 treated with PS, 4 treated with FCSEMS]; FCSEMS: 1 [treated with PS]) due to stent migration (PS: 3; FCSEMS: 1) or inadequate drainage (PS: 10). Technical success was 100%. Initial clinical success was 64.9% (25/38) for PS versus 91.7% (11/12) for FCSEMS (P = 0.074). With repeat transmural stenting, final clinical success was achieved in 94.6% and 100%, respectively (P = 0.411). Compared to FCSEMS, PS was associated with greater need for repeat drainage (34.2% vs. 6.3%, P = 0.032). The need for and frequency of DEN was similar between both groups, but PS required more frequent balloon dilatation. PS was significantly cheaper for noninfected PC. Costs were similar for infected PC and WON. Conclusion: PS was associated with a higher need for a second drainage procedure to achieve clinical success. The use of FCSEMS did not increase procedural costs for infected PC and WON.

Ten‐day triple therapy versus sequential therapy versus concomitant therapy as first‐line treatment for Helicobacter pylori infection

Clarithromycin‐based triple therapy (TT) is the first‐line treatment for Helicobacter pylori infection in Singapore. There is awareness that TT may no longer be effective due to increased clarithromycin resistance rates. Sequential therapy (ST) and concomitant therapy (CT) are alternative treatment regimens. This study aimed to compare the efficacy of 10‐day TT, ST, and CT as first‐line treatment for H. pylori infection.

The Changing Profile of Helicobacter pylori Antibiotic Resistance in Singapore: A 15-Year Study.

Antibiotic resistance is an important cause of H. pylori treatment failure. This study aimed to examine the change in H. pylori antibiotic resistance profile in Singapore over the course of 15 years.

Endosonography-guided fine needle aspiration cytology of intra-abdominal lymph nodes with unknown primary in a tuberculosis endemic region

Background and Aim:  Intra‐abdominal lymphadenopathy poses a diagnostic and management challenge in highly endemic regions for tuberculosis. Opting for empirical anti‐tuberculosis treatment raises the risk of wrong or delayed treatment. Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) is the procedure of choice for tissue acquisition from peri‐luminal lymph nodes. We studied the utility of EUS‐FNA in evaluating intra‐abdominal lymph nodes of unknown etiology, in the setting of high endemicity of tuberculosis.

A multicenter randomized comparison between high-definition white light endoscopy and narrow band imaging for detection of gastric lesions.

Objective Narrow band imaging (NBI) is generally considered to be useful for lesion characterization, but not enhanced detection of gastric lesions, because of the dark endoscopic view. We tested whether the new generation of NBI (190-NBI or 290-NBI), which is twice as bright as the previous version, would improve detection of premalignant gastric lesions compared with high-definition white light endoscopy (HD-WLE). Patients and methods This was a multicenter prospective randomized study involving five tertiary institutions in the Asia-Pacific region. A total of 579 patients aged older than 50 years who underwent diagnostic upper gastrointestinal endoscopy were randomized to either HD-WLE or NBI. The outcome measurements were detection of intestinal metaplasia (IM), focal gastric lesions, and gastric cancers. Results Focal gastric lesions were detected in 83/286 (29%) and 119/293 patients (40.6%) by HD-WLE and by NBI, respectively (P=0.003). IM was detected in 22/286 patients (7.7%) by HD-WLE and in 52/293 patients (17.7%) by NBI (P<0.001). Gastric cancer were found in 7/286 (2.4%) and 3/293 patients (1%) in HD-WLE and NBI groups, respectively (P=0.189). Conclusion NBI increased the detection rate of IM compared with HD-WLE.

Efficacy of small-volume simethicone given at least 30 min before gastroscopy

AIM To evaluate the efficacy of 5 mL simethicone solution in decreasing gastric foam if given at least 30 min before gastroscopy. METHODS This was a randomized, placebo controlled, endoscopist blinded study performed at Changi General Hospital. Patients were at least 21 years old, had no prior surgical resection of the upper gastrointestinal tract, and scheduled for elective diagnostic gastroscopies. The primary outcome was the total mucosal visibility score (TMVS) which was evaluated using McNally score. The sample size was calculated to be 24 per group (SD 2.4, 80% power, P < 0.05, 2-sample t test). RESULTS Fifty-four patients were randomised to receive either simethicone [1 mL liquid simethicone (100 mg) in 5 mL of water] or placebo (5 mL of water) at least 30 min before their gastroscopy. Six accredited consultants conducted the gastroscopy, and the interobserver agreement of scoring TMVS was good with a Kappa statistic of 0.73. The simethicone group had significantly better mean TMVS compared to placebo (5.78 ± SD 1.65 vs 8.89 ± SD 1.97, P < 0.001). The improvement was statistically significant for the duodenum and the gastric antrum, angularis, body, and fundus. Percent 51.9 of patients in the simethicone group had a TMVS of 4 (no bubbles at all) to 5 (only 1 area with minimal bubbles), while in the placebo group 3.7% of patients had TMVS of 4 or 5. The number needed to treat was 2.1 to avoid a TMVS of 6 and more. The simethicone group also had a significantly shorter procedure time with less volume of additional flushes required during gastroscopy to clear away obscuring gastric foam. CONCLUSION With a premedication time of at least 30 min, 5 mL simethicone can significantly decrease gastric foam, decrease the volume of additional flushes, and shorten gastroscopy time.

A prospective randomized study of the difference in diagnostic yield between endoscopic ultrasound-guided fine-needle aspiration (EUSFNA) needles with and without a side port in pancreatic masses

Background and study aims: Two 22G needles with similar designs, apart from the absence (A) or presence of a side port (B), are available for endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA). The side port was designed to increase diagnostic yield but this advantage was unproven. This study evaluated the difference in diagnostic yield between both needles in pancreatic masses. Patients and methods: This was a prospective multicenter randomized cross-over study. Patients with pancreatic masses were randomized to one needle for the first two passes, followed by the other for the next two passes. A pathologist blinded to the needle assessed each puncture for cellularity and morphology. The diagnostic yield between both needles was compared. Results: In total, 30 patients were recruited (mean lesion size: 3.5 cm, range: 1.2 – 6.3). Comparison of cellularity adequacy: first pass: A vs. B: 26/30 vs. 24/30 (P = 0.488): 2nd pass: A vs. B: 25/30 vs. 26/30 (P = 0.718). Comparison of diagnostic accuracy: first pass: A vs. B: 22/30 vs. 23/30 (P = 0.766); after two passes: A vs. B: 26/30 vs. 26/30 (P = 1.0). When all four passes were assessed, adequate cellularity was obtained in 29/30 and the correct diagnosis was obtained in 28/30 patients. There were no procedural complications. Conclusions: There was no significant difference in diagnostic yield between EUSFNA needles with or without a side port for pancreatic masses. Study registration: NCT02092519.

Endoscopic ultrasound-guided insertion of a large diameter fully covered self-expandable metallic stent as rescue therapy for recurrent infected walled off pancreatic necrosis after surgical necrosectomy

A 39-year-old man developed severe necrotizing gallstone pancreatitis complicated by infected pancreatic necrosis. Surgical necrosectomy was performed to control the on-going sepsis. Subsequently, there was a recurrence of an infected necrotic collection at the site of surgical necrosectomy, in the region of the pancreatic body and tail. He did not respond to conservative treatment with intravenous antibiotics. Pancreatic duct stenting was performed to treat pancreatic duct leak, followed by endoscopic ultrasound guided insertion of a large diameter fully covered self-expandable metallic stent to drain the infected collection. There was rapid and complete clinical recovery.

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.