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James Y W Lau

Publications and source records attributed to James Y W Lau.

At least 19 recordsLinked to original sources
PubMed2006

Effects of long-term rofecoxib on gastric intestinal metaplasia: results of a randomized controlled trial.

PURPOSE: Gastric cancer and its premalignant gastric lesion, intestinal metaplasia (IM), frequently express cyclooxygenase-2 (COX-2) at high levels. We tested whether long-term use of specific COX-2 inhibitors regress gastric IM. EXPERIMENTAL DESIGN: This is a double-blind, randomized, placebo-controlled trial. Individuals with confirmed IM and Helicobacter pylori clearance were randomized to receive rofecoxib 25 mg daily or placebo. Endoscopy was done at baseline, at the end of year 1, and at the end of year 2, with multiple biopsies taken from the antrum and corpus. The primary end point was the proportion of subjects with regression of IM. Secondary end points were the severity of other histologic variables and the proportion of subjects with complete regression of IM. RESULTS: Two-hundred and thirteen subjects with confirmed IM were randomized. The proportion of subjects with the regression of IM did not differ significantly between rofecoxib and placebo groups (antrum, 24.5% versus 26.9%; P = 0.74; corpus, 4.3% versus 2.2%; P = 0.68). Patients on rofecoxib (19.1%) and on placebo (16.1%) had no IM detected in the stomach (P = 0.59). There was also no significant difference in the severity of IM between the two treatment groups (P >or= 0.3). CONCLUSIONS: There was no trend to suggest that treatment with rofecoxib for 2 years resulted in the regression of gastric IM. Although our findings cast doubt on the reversibility of gastric IM by COX-2 inhibitor, further studies are needed to establish the role of COX-2 inhibitors in different stages of gastric carcinogenesis.

Adenocarcinoma↗
PubMed2006

Endoscopic plication of massively bleeding peptic ulcer by using the Eagle Claw VII device: a feasibility study in a porcine model.

BACKGROUND AND OBJECTIVE: We examined the efficacy of endoscopic plication when using Eagle Claw VII in a porcine bleeding ulcer model. ANIMAL MODEL PREPARATION: The right gastroepiploic artery (diameter 1.5-2 mm) was isolated and was tunneled to small gastrotomies at either the lesser or greater curvature of the stomach. INTERVENTIONS: We applied the Eagle Claw VII to achieve hemostasis. MAIN OUTCOME MEASUREMENTS: The survival of the pigs after endoscopic plication for hemostasis, time to achieve hemostasis with Eagle Claw VII, recurrent bleeding, number of successful plication, and number of suture remained. RESULTS: Endoscopic plication was performed on bleeding gastric ulcers in 6 pigs. The time to achieve hemostasis was 6 minutes 56 seconds +/- 3 minutes 50 seconds. There was no complication. A total of 14 plications were performed. All animals survived for 1 week without recurrent bleeding. At the postmortem, 10 of the plication sutures remained. LIMITATION: Our model cannot simulate the chronicity of peptic ulcer. CONCLUSIONS: In this porcine model, the Eagle Claw VII effectively stopped bleeding from arteries 2 mm in size.

Animals↗
PubMed2006

Colorectal neoplasia in Asia: a multicenter colonoscopy survey in symptomatic patients.

BACKGROUND: The incidence of colorectal cancer is rising rapidly in some Asian countries. OBJECTIVE: To determine the prevalence and the distribution of colorectal neoplasm in Asian populations. DESIGN: A multicenter colonoscopy survey. PATIENTS: Between July 2004 and April 2005, consecutive symptomatic patients undergoing colonoscopic examinations in 10 different Asian countries. SETTING: The location and the histologic features of all colonic neoplasms were recorded. Advanced neoplasm was defined as adenoma larger than 10 mm in size, with >25% villous features or with high-grade dysplasia or invasive carcinoma. MAIN OUTCOME MEASUREMENTS: The prevalence and the distribution of colorectal neoplasm and advanced neoplasm. RESULTS: A total of 5464 eligible patients underwent colonoscopy. Advanced neoplasm was found in 512 patients (9.4%). Factors associated with the presence of advanced neoplasm in this symptomatic Asian population included male sex (relative risk [RR] 1.52, 95% confidence interval [CI] 1.26-1.84), older age (RR 1.05, 95% CI 1.04-1.06), and ethnicity (P = .001). Advanced proximal neoplasm was detected in 136 patients (2.5%); 83 (61.0%) of the patients had normal distal colon. The RR of proximal advanced neoplasm was 2.5, 95% CI 1.7-3.7 in those with any adenoma in the distal colon compared with those with normal distal colon. LIMITATIONS: Possible underrepresentation of some ethnic groups because of uneven ethnic group distribution and the lack of population-based registry. CONCLUSIONS: This was the first multicenter colonoscopy survey that examined the characteristics of colorectal neoplasm in Asia. The results will have important implications on the planning for future colorectal cancer screening in this region.

Adenoma↗
PubMed2006

Cholecystectomy or gallbladder in situ after endoscopic sphincterotomy and bile duct stone removal in Chinese patients.

BACKGROUND & AIMS: In patients with stones in their bile ducts and gallbladders, cholecystectomy is generally recommended after endoscopic sphincterotomy and clearance of bile duct stones. However, only approximately 10% of patients with gallbladders left in situ will return with further biliary complications. Expectant management is alternately advocated. In this study, we compared the treatment strategies of laparoscopic cholecystectomy and gallbladders left in situ. METHODS: We randomized patients (>60 years of age) after endoscopic sphincterotomy and clearance of their bile duct stones to receive early laparoscopic cholecystectomy or expectant management. The primary outcome was further biliary complications. Other outcome measures included adverse events after cholecystectomy and late deaths from all causes. RESULTS: One hundred seventy-eight patients entered into the trial (89 in each group); 82 of 89 patients who were randomized to receive laparoscopic cholecystectomy underwent the procedure. Conversion to open surgery was needed in 16 of 82 patients (20%). Postoperative complications occurred in 8 patients (9%). Analysis was by intention to treat. With a median follow-up of approximately 5 years, 6 patients (7%) in the cholecystectomy group returned with further biliary events (cholangitis, n = 5; biliary pain, n = 1). Among those with gallbladders in situ, 21 (24%) returned with further biliary events (cholangitis, n = 13; acute cholecystitis, n = 5; biliary pain, n = 2; and jaundice, n = 1; log rank, P = .001). Late deaths were similar between groups (cholecystectomy, n = 19; gallbladder in situ, n = 11; P = .12). CONCLUSIONS: In the Chinese, cholecystectomy after endoscopic treatment of bile duct stones reduces recurrent biliary events and should be recommended.

Aged↗
PubMed2006

Helicobacter pylori infection in 1st degree relatives of Chinese gastric cancer patients.

OBJECTIVE: Familial aggregation of gastric cancer has been linked to familial clustering of Helicobacter pylori infection. Patterns and risk factors associated with H. pylori infection were investigated in 1st degree relatives of Chinese gastric cancer patients. MATERIAL AND METHODS: Gastric cancer relatives were invited for screening endoscopy. H. pylori infection was diagnosed by endoscopic and serological methods. RESULTS: Among the 270 cancer relatives examined, 161 (59.6%) were found to be infected with H. pylori. The prevalence of infection in cancer relatives was significantly higher than age- and gender-matched dyspeptic control (45.5%, p=0.0006). The mean age of H. pylori-infected relatives was significantly older than that of non-infected relatives (43.9 versus 38.3 years; p<0.001). The prevalence of H. pylori infection was higher in those with more siblings (p=0.013, chi(2) test for trend). Moreover, individuals whose siblings had stomach cancer were more likely to have H. pylori infection than those with a parental history of cancer (68.2% versus 51.8%, p=0.007). In contrast, the youngest sibling had a significantly lower H. pylori infection rate than other siblings (39.2% versus 64.2%, p=0.001). Using multiple logistic regression, it was found that age >45 years (OR=1.8; 95% CI, 1.02-3.3) and a history of gastric cancer in siblings (OR=1.9; 95% CI, 1.06-3.3) were independent risk factors for H. pylori infection, and that the youngest sibling in the family had a reduced risk (OR=0.45; 95% CI, 0.24-0.84). CONCLUSIONS: This study identifies the patterns and risk factors for H. pylori in gastric cancer relatives, which may shed light on the evolving epidemiology of H. pylori infection in Chinese patients.

Adolescent↗
PubMed2006

Endolaparoscopic left hemicolectomy and synchronous laparoscopic radical nephrectomy for obstructive carcinoma of the descending colon and renal cell carcinoma.

Colorectal self-expandable metal stents (SEMS) have been used successfully as preoperative bridges to surgery for obstructive left-sided colorectal carcinoma. Endoscopic relief of the obstruction allows for full bowel preparation and accurate preoperative staging. A laparoscopic approach, considered by many to be contraindicated in the presence of obstruction, becomes feasible after endoscopic decompression. We present a case of obstructive carcinoma of the descending colon successfully treated with endoscopic decompression with colorectal SEMS. Subsequent staging with computed tomography revealed a renal cell carcinoma in the left kidney. Synchronous laparoscopic resection of the two carcinomas was performed, with no morbidity. To the best of our knowledge, this is the first report of endolaparoscopic left hemicolectomy and synchronous laparoscopic radical nephrectomy for obstructive carcinoma of the descending colon and renal cell carcinoma. The advantages of colorectal SEMS and the endolaparoscopic approach in managing obstructive colorectal carcinoma are discussed.

Aged, 80 and over↗
PubMed2006

Inter-observer variations on interpretation of capsule endoscopies.

OBJECTIVE: Capsule endoscopy is a novel investigation for diagnosing small bowel diseases. However, its interpretation is highly subjective and the potential variability may compromise its accuracy and reliability. Here we studied the potential inter-observer variations on the interpretation of capsule endoscopy. METHOD: Two residents and one specialist in gastroenterology independently reviewed 58 capsule endoscopy studies in the same sequential order. The gastric transit time, small bowel transit time, and the most significant small bowel lesion were independently recorded. The consensus transit time was determined by the joint review of the three gastroenterologists. The 'gold standard' for small bowel diagnoses was based on final surgical, endoscopic findings or consensus diagnosis. RESULTS: Clinically significant and relevant small bowel lesions were found in 32 (55%) cases by consensus review. The overall mean accuracy in determining gastric emptying time, small bowel transit time and small bowel lesion was 89%, 76% and 80%, respectively. There was a significant difference in the accuracy between the residents and specialist on small bowel transit time (P<0.05) and small bowel diagnosis (P<0.05). The mean kappa values on small bowel diagnosis among the three viewers was 0.56 (range, 0.52-0.59). Among various small bowel diagnoses, small bowel bleeding was more accurately identified than other pathology. CONCLUSIONS: Our results show that there is moderate degree of inter-observer discrepancies on the interpretation of capsule endoscopy. A second reading by an experienced viewer might improve the diagnostic accuracy of this investigation.

Adolescent↗
PubMed2006

H. pylori genotypes and cytokine gene polymorphisms influence the development of gastric intestinal metaplasia in a Chinese population.

BACKGROUND: Cytokine gene polymorphisms and Helicobacter pylori (HP) genotypes have been linked to gastric cancer development in Western countries. We determined the role of host cytokine polymorphisms and bacterial virulent factors in the development of gastric intestinal metaplasia (IM) in a Chinese population with a high background gastric cancer incidence. METHODS: Three hundred two HP-infected noncancer individuals living in Shandong province of China with available DNA were studied. Polymorphisms in different loci of inflammatory cytokines Interleukin IL-1B, IL-1RN, Interleukin IL-8, IL-10, IL-18, tumor necrosis factor-A (TNF-A), and Transforming growth factor (TGF-B), were determined by allelic discriminating TaqMan polymerase chain reaction (PCR) or a variable number of tandem repeats. Presence of HP virulence factors in cagA, vacA, and babA2 were determined by PCR. Baseline gastric biopsies were assessed for the presence of IM. RESULTS: Among HP-infected subjects, carriers of the IL-1B-511 T allele were associated with a modestly greater prevalence of IM (adjusted OR 2.0, 95% CI 1.0-3.7). There was no association between the presence of IM and polymorphisms in other inflammatory cytokines. Although most subjects from this region harbored the virulent HP strains, carriage of the vacA m1 strain was associated with a significantly higher prevalence of IM (adjusted OR 1.8, 1.1-3.0). The presence of both host (IL-1B-511 T) and HP (vacA m1) genotypes further increased the risk of IM (OR 5.7, 2.0-16) when compared with individuals with the low-risk genotype. CONCLUSION: The carriage of proinflammatory IL-1B-511 and HP vacA m1 genotypes was associated with the development of gastric IM in the Chinese.

China↗
PubMed2006

Long-term follow-up of patients with obscure gastrointestinal bleeding after negative capsule endoscopy.

BACKGROUND AND AIMS: Capsule endoscopy (CE) is one of the widely accepted investigations for obscure gastrointestinal bleeding (OGIB), but little is known about the impact of CE on the long-term outcome of patients with OGIB. We studied the long-term outcome of patients with OGIB after CE examination. PATIENTS AND METHODS: Forty-nine consecutive patients (45% men, mean age 58.3 yr) who underwent CE for OGIB were studied. The most clinically relevant finding that was related to bleeding was identified by CE. All patients were followed up for at least 12 months for clinical overt and occult bleeding. RESULTS: The median follow-up was 19 months (range 12 to 31). Possible bleeding lesions were detected by CE in 31 (63.3%) patients, and 15 (30.6%) patients, underwent further interventions including laparotomy and push enteroscopy. The overall long-term rebleeding rate in this cohort was 32.7%. The cumulative rebleeding rate was significantly lower in patients with a negative CE (5.6%) than in patients with a positive CE (48.4%, p=0.03 log-rank test). The sensitivity and negative predictive value of CE in predicting rebleeding were 93.8% and 94.4%, respectively. CONCLUSIONS: Patients with OGIB and negative CE had a very low rebleeding rate, and further invasive investigations can be deferred.

Adolescent↗
PubMed2005

Clopidogrel versus aspirin and esomeprazole to prevent recurrent ulcer bleeding.

BACKGROUND: Concurrent therapy with a proton-pump inhibitor is a standard treatment for patients receiving aspirin who are at risk for ulcer. Current U.S. guidelines also recommend clopidrogel for patients who have major gastrointestinal intolerance of aspirin. We compared clopidogrel with aspirin plus esomeprazole for the prevention of recurrent bleeding from ulcers in high-risk patients. METHODS: We studied patients who took aspirin to prevent vascular diseases and who presented with ulcer bleeding. After the ulcers had healed, we randomly assigned patients who were negative for Helicobacter pylori to receive either 75 mg of clopidogrel daily plus esomeprazole placebo twice daily or 80 mg of aspirin daily plus 20 mg of esomeprazole twice daily for 12 months. The end point was recurrent ulcer bleeding. RESULTS: We enrolled 320 patients (161 patients assigned to receive clopidogrel and 159 to receive aspirin plus esomeprazole). Recurrent ulcer bleeding occurred in 13 patients receiving clopidogrel and 1 receiving aspirin plus esomeprazole. The cumulative incidence of recurrent bleeding during the 12-month period was 8.6 percent (95 percent confidence interval, 4.1 to 13.1 percent) among patients who received clopidogrel and 0.7 percent (95 percent confidence interval, 0 to 2.0 percent) among those who received aspirin plus esomeprazole (difference, 7.9 percentage points; 95 percent confidence interval for the difference, 3.4 to 12.4; P=0.001). CONCLUSIONS: Among patients with a history of aspirin-induced ulcer bleeding whose ulcers had healed before they received the study treatment, aspirin plus esomeprazole was superior to clopidogrel in the prevention of recurrent ulcer bleeding. Our finding does not support the current recommendation that patients with major gastrointestinal intolerance of aspirin be given clopidogrel.

Aged↗
PubMed2005

Premedication with orally administered midazolam in adults undergoing diagnostic upper endoscopy: a double-blind placebo-controlled randomized trial.

BACKGROUND: A double-blind placebo-controlled randomized trial was conducted to investigate the safety and the efficacy of orally administered midazolam as premedication for patients undergoing elective EGD. METHODS: A total of 130 patients were randomized to receive either 7.5 mg of midazolam orally (n = 65) or a placebo (n = 65) as premedication. Outcomes measures included the anxiety score (visual analog scale) during EGD, overall tolerance, extent of amnesia, overall satisfaction, patient willingness to repeat the procedure, recovery time, and hemodynamic changes after medication. RESULTS: The median (interquartile range) anxiety score during the procedure in the midazolam group was significantly lower than that in the control group (2.0 [0-4.9] vs. 3.8 [2.1-7.95], p < 0.001). A significantly greater number of patients in the midazolam group graded overall tolerance as "excellent or good" (70.8% vs. 49.2%, p = 0.012) and reported a partial to complete amnesia response (52.3% vs. 32.3%, p = 0.02) when compared with the control group. Patients in the midazolam group were more willing to repeat the procedure if necessary (89.2% vs. 69.2%, p = 0.005). The median (interquartile range) recovery time was significantly longer in the midazolam group than in the control group (5 [5-15] minutes vs. 5 [5-10] minutes, p = 0.014). There were no statistically significant differences in satisfaction score and hemodynamic changes between groups. CONCLUSIONS: Premedication by oral administration of midazolam is a safe and an effective method of sedation that significantly reduces anxiety and improves overall tolerance for patients undergoing EGD.

Administration, Oral↗
PubMed2005

Endoscopic suturing without extracorporeal knots: a laboratory study.

BACKGROUND: To eliminate cumbersome extracorporeal knotting, we designed a new endoscopic suturing device, the Eagle Claw V. The efficacy of the new device was tested on the Erlangen model and was compared with the initial extracorporeal knotting version (Eagle Claw II). METHODS: Segments of porcine splenic arteries were placed on the mucosal surface of the anterior wall of a pig stomach. The two ends of the artery were brought out through the gastric wall and were connected to a two-channel manometer. The Eagle Claw V has a curved needle with a detachable tip. After puncturing the tissue, the needle tip was engaged into a catching cartridge, where the suture had been embedded in a tightening mechanism. The suture could be tightened by simply pulling the end. The Eagle Claw V was used to plicate the splenic arteries mounted on the stomach. Suturing was considered secure if the suture could withstand endoluminal pressure greater than 200 mm Hg that lasted at least 10 seconds. RESULTS: Eleven of 15 stitches (73.3%) gained secure plication of the vessels. The suturing time (mean +/- standard deviation 2.93 +/- 0.80 minutes) was significantly faster than that of the Eagle Claw II (9.38 +/- 1.51 minutes). The device consistently achieved penetration of the muscular layer, and 4 of 15 sutures included the serosa. The 4 failures were because of suture breakage in two, thread entanglement in one, and cartridge dislodgement in one. CONCLUSIONS: The present prototype represents significant improvements in the ease of operation and the security of the suture, bringing the technique closer to clinical use for a variety of applications.

Animals↗
PubMed2005

Increasing incidence of colorectal cancer in Asia: implications for screening.

Many Asian countries, including China, Japan, South Korea, and Singapore, have experienced an increase of two to four times in the incidence of colorectal cancer during the past few decades. The rising trend in incidence and mortality from colorectal cancer is more striking in affluent than in poorer societies and differs substantially among ethnic groups. Although changes in dietary habits and lifestyle are believed to be the reasons underlying the increase, the interaction between these factors and genetic characteristics of the Asian populations might also have a pivotal role. Non-polypoidal (flat or depressed) lesions and colorectal neoplasms arising without preceding adenoma (de novo cancers) seem to be more common in Asian than in other populations. The absence of polypoid growth preceding malignancy has posed difficulties in screening for early colorectal cancer by radiological imaging or even endoscopic techniques. Although epidemiological data are scanty, most Asian populations are not aware of the growing problem of colorectal cancer. More work is needed to elucidate the magnitude of the problem in Asia.

Asia↗
PubMed2005

Endovascular treatment of a large fusiform splenic artery aneurysm with a coaxial technique using a 5-f balloon catheter and a microcatheter.

A coaxial technique was introduced for successful embolization of a large fusiform splenic artery aneurysm in a vessel with a large caliber and a great degree of tortuosity. A standard 5-F angioplasty catheter was placed at the immediate afferent artery for occlusion of arterial inflow into the aneurysm, thereby preventing intraaneurysmal hypertension during embolization of the efferent segment. This was followed by coaxial microcatheterization of the immediate efferent segment for coil embolization, and then embolization of the afferent segment. It is postulated that this approach may improve the safety of embolization of large aneurysms with unfavorable morphology by decreasing the pressure on the aneurysm just after closure of the efferent segment.

Aged↗
PubMed2005

Risk factors associated with the development of intestinal metaplasia in first-degree relatives of gastric cancer patients.

Family relatives of gastric cancer patients have a higher risk of gastric cancer and premalignant gastric lesions. We sought to determine the risk factors associated with the presence of intestinal metaplasia in a large cohort of gastric cancer relatives. First-degree relatives of gastric cancer patients were invited for screening gastroscopy. Endoscopic gastric biopsies were obtained from the antrum and corpus. Gastric biopsies were analyzed for Helicobacter pylori infection, severity of inflammation, and presence of intestinal metaplasia. Stepwise logistic regressions were used to identify for risk factors associated with presence of intestinal metaplasia in cancer relatives. Two hundred seventy cancer relatives underwent screening endoscopy (median age, 42; 47% male and 48% siblings). Among them, 161 (59.6%) were H. pylori positive and 81 (30%) had confirmed intestinal metaplasia. The following factors were found to be associated with the presence of intestinal metaplasia: age, male sex, H. pylori infection, birth order, alcohol use, siblings with stomach cancer, childhood living conditions, and water supply. Individuals with intestinal metaplasia had more severe acute and chronic inflammation in the antrum and corpus (P < 0.003). With multiple logistic regression, H. pylori infection [odds ratio (OR), 3.23], male gender (OR, 2.09), age (OR, 1.07), and a history of gastric cancer in siblings (OR, 1.91) were independent factors associated with the development of intestinal metaplasia in cancer relatives. In conclusion, we have identified risk factors associated with gastric intestinal metaplasia in stomach cancer relatives, which may be useful in the understanding of gastric carcinogenesis in these high-risk individuals.

Adenocarcinoma↗