Helical stent (SUPERA™) and drug-coated balloon (Passeo-18 Lux™) for recurrent cephalic arch stenosis: Rationale and design of arch V SUPERA-LUX Study.

BACKGROUND: The treatment options for cephalic arch stenosis are limited and standard of care remains at crossroads - none are ideal and there is currently no gold standard. Endovascular techniques are now the preferred primary therapeutic option because they are minimally invasive and better tolerated by haemodialysis patients who have multiple comorbidities. However, conventional plain old balloon angioplasty, bare metal stenting and stent grafts all have their limitations. The aim of this trial is to evaluate whether the helical SUPERA™ stent (Abbott Vascular, Santa Clara, CA, USA), which has a higher degree of flexibility and resistance to compressive forces compared to traditionally laser-cut nitinol stents, combined with a drug-coated balloon (Biotronik Passeo-18 Lux™) to minimize the neointimal hyperplasia effect, can improve patency and reduce reintervention rates. METHODS AND RESULTS: Arch V SUPERA-LUX is a pilot investigator-initiated single-centre, single-arm prospective study. Twenty patients with a brachiocephalic fistula within 6 months of initial plain old balloon angioplasty for significant cephalic arch stenosis will be recruited for treatment with SUPERA and drug-coated balloon. The primary objectives are immediate angiographic and procedural success, primary patency and functional fistula at 1 week, 8 weeks, 6 and 12 months. The results from eight patients treated prospectively as proof of concept have shown primary patency of 83.3% at 1 year with 100% technical and procedural success rates. Enrolment for the Arch V SUPERA-LUX study is expected to be completed at the end of 2019. CONCLUSION: The Arch V SUPERA-LUX study is the first trial to evaluate whether SUPERA stent implantation and drug-coated balloon use can provide superior protection against restenosis compared to traditional angioplasty, bare metal stents and stent grafts in recurrent cephalic arch stenosis. Initial pilot results are encouraging but longer follow-up is required to truly test this technique. TRIAL REGISTRATION: This study is registered on ClinicalTrials.gov NCT03891693.

Morphology and properties of denture acrylic resins cured by microwave energy and conventional water bath.

OBJECTIVES: This study examined the influence of microwave energy levels on the morphology and properties of an impact resistant denture material poly(methyl methacrylate) with a thickness of 10 mm. METHODS: A microwave flask containing two resin blocks was processed at 80, 160, 240, and 560 W for 15, 10, 7, and 2 min, separately. Each Flask was then turned over, and cured for an additional 2 min at 560 W. The process using conventional methods was carried out at 70 degrees C for 9 h. The blocks were tested for hardness, porosity, flexural properties, solubility, and molecular weight. The morphology of the specimens after staining with osmium tetroxide was examined by transmission electron microscope. RESULTS: The changes in temperature with time were recorded during microwave heating at 80, 160, and 240 W, respectively. A significantly large difference in the curing temperature was observed when comparing these two processing methods. There was little difference in the mean values of surface hardness and the weight percent of the insoluble parts. The mean domain size and the volume fraction of the rubber phase favor of the water-bath method. However, the porosity in the water-bath-cured specimens was much less than that in the microwave-cured specimens. Thus, the conventionally cured specimens showed better flexural strength and flexural modulus than the microwave-cured specimens. SIGNIFICANCE: This study has shown that microwave energy can efficiently polymerize denture base polymer. Highly statistical differences in morphology and flexural properties favor of the water-bath method. Choice of a suitable microwave power and polymerization time is important in order to reduce porosity to a minimum level and increase the domain size and volume of the rubber phase.

A prospective study of the clinical features, manometric findings, incidence and prevalence of achalasia in Singapore.

BACKGROUND: This study aimed to describe the clinical features, manometric findings, prevalence and incidence of achalasia in Singapore. METHODS: A total of 615 new patients referred for oesophageal manometry between 1989 and 1996 were examined prospectively. Twenty-four men and 25 women fulfilled the manometric and clinical criteria for achalasia. RESULTS: Their median age of onset of symptoms was 37 years (range 15-71) and 37% first developed symptoms after the age of 50 years. The presenting symptoms were dysphagia (100%), regurgitation (80%), weight loss (67%) and chest discomfort (33%). Five patients (10%) had a history of benign (mostly autoimmune) thyroid disorders. Endoscopy was reported as normal in 10/43 patients (23%) and achalasia was suggested in only 31 (72%) of 43 barium examinations. Lower oesophageal sphincter (LOS) dysfunction was present in 82% of cases. Using data from medical records and from a survey of gastroenterologists and surgeons in Singapore, the prevalence (in 1996) and incidence of achalasia in Singapore were estimated to be 1.8 per 100000, and 0.3 per 100000 per year, respectively. The incidence was significantly lower in Malays than Chinese or Indians. The age-specific incidence of achalasia for both genders followed a bimodal distribution with the larger peak in the sixth decade. No cases of oesophageal carcinoma were identified among these patients. CONCLUSION: Achalasia is an uncommon condition in Singapore. The clinical and manometric features were similar to those described in Western countries.

Effect of cisapride on functional dyspepsia in patients with and without histological gastritis: a double-blind placebo-controlled trial.

In the present double-blind placebo-controlled study the effect of cisapride on functional dyspepsia was evaluated in patients with and without histological gastritis. Patients with functional dyspepsia and whose symptoms persisted after a 2 week run-in period with antacid treatment were randomized to receive cisapride (10 mg) or matching placebo three times daily for 4 weeks. Symptoms of epigastric pain, bloating, nausea, belching, early satiety and heartburn were graded on a four-point scale based on patients' feedback and diary card recording. A global response was also formulated by the investigators. One hundred and four patients entered the study and 76 completed the trial, comprising 36 patients with histological gastritis and 40 patients without gastritis. Symptom scores in both gastritis and non-gastritis groups were significantly improved by both cisapride and placebo; however, the improvement was not statistically different between the two treatment groups. Cisapride produced a good or better global response in 58% of subjects with histological gastritis and in 53% of subjects without gastritis compared with 47% and 52%, respectively, of patients on placebo; this difference was not statistically significant. Gastric histology did not influence the effect of cisapride on the symptoms of functional dyspepsia.

Primary biliary cirrhosis--an uncommon disease in Singapore.

Primary biliary cirrhosis (PBC) is uncommon in Singapore. Twelve consecutive patients with PBC were seen between 1987 and 1994 at the National University Hospital. Eleven were women and the mean age at presentation was 53 years. Three patients presented with pruritus and jaundice whilst three had decompensated cirrhosis. The remaining six patients had no symptoms attributed to their liver disease when first detected, three of them presented with associated conditions including sicca syndrome and interstitial lung fibrosis, lichen planus, and carcinoma of breast. All patients had elevated serum alkaline phosphatase and positive anti-mitochondrial antibodies. Liver histology (10/12) showed Stage II disease (2), Stage III (5) and Stage IV (3). Three patients also had co-existing gall bladder stones but their endoscopic retrograde cholangiograms were normal. The mean follow-up period was 32.6 months and four patients died during follow-up. The only male patient had liver transplantation, two patients had symptomatic treatment while the rest were treated with ursodeoxycholic acid. In conclusion, local patients tended to presented relatively early in the course of the disease with 50% being asymptomatic and in the precirrhotic Stages.

Seroprevalence of antibodies against hepatitis A (anti-HAV) in Singapore: the NFDD experience.

At the 4th National Foundation for Digestive Disease (NFDD) Day in 1991 where public lectures on prevention of hepatitis and early detection of hepatocellular carcinoma were given, screening of sera obtained from 364 registrants for antibodies to Hepatitis A (IgG) was undertaken. The overall sero-prevalence rate was 50%, with 55% for males and 46% for females with antibodies for HAV. None of the subjects below 20 years old had antibodies to HAV. This rose to 16% for those 21-30 years old and 92% for those above 61 years. This study shows that in Singapore, prevalence of anti-HAV antibodies rise with age and is approaching the low endemicity pattern that is seen in developed countries.

Low frequency of endoscopic esophagitis in Asian patients.

The aim of this study was to determine the frequency of endoscopic esophagitis in patients seen for upper gastrointestinal complaints in an Asian center. We studied a consecutive series of 11,943 patients undergoing diagnostic esophagogastroduodenoscopy at our unit over a 10-year period. Three hundred and eighty-nine patients (3.3%) had endoscopic esophagitis with no other significant lesion (primary esophagitis), whereas 143 (1.2%) had esophagitis associated with peptic ulcer or gastric or duodenal malignancy (secondary esophagitis). In contrast, peptic ulcer was diagnosed in 2,787 patients (23.3%) and gastric carcinoma in 286 (2.4%). The reported frequency of endoscopic esophagitis among patients undergoing endoscopy in Western countries varied from 9 to 23%. Our data therefore show that endoscopic esophagitis is much less common in Singaporean patients.

Inflammatory bowel disease: an uncommon problem in Singapore.

Fifty patients with inflammatory bowel disease (ulcerative colitis, 40; Crohn's disease, seven; indeterminate colitis, three) treated in one gastroenterology unit in Singapore over a 10 year period were reviewed. Clinical features were similar to those described in Western patients. Of the three main races of Singapore it was found that Indians are more susceptible to these diseases than Chinese or Malays. A survey of all gastroenterologists in Singapore indicated a possible prevalence of 8.6 per 100,000 people for ulcerative colitis and 1.3 per 100,000 people for Crohn's disease. These prevalence rates are much lower than those reported for Western populations.

Chronic upper abdominal pain: site and radiation in various structural and functional disorders and the effect of various foods.

Pain site and radiation and the effect of various foods were studied prospectively in a consecutive series of patients with chronic upper abdominal pain. Patients followed for less than one year were excluded unless peptic ulcer or abdominal malignancy had been diagnosed or laparotomy had been carried out. A total of 632 patients were eligible for the first study and 431 for the second. Gastric ulcer pain was more likely to be left hypochondrial (17%) compared with pain from duodenal ulcer (4%) or from all other conditions (5%). It was less likely to be epigastric (54%) compared with duodenal ulcer pain (75%). Oesophageal pain was more likely to be both retrosternal and epigastric (25%) compared with non-oesophageal pain (2%). Radiation to the back was more common in peptic ulcer (31%) and biliary pain (35%) compared with functional pain (20%). Pain precipitation by fatty foods was commoner in biliary disease (40%) than in duodenal ulcer (11%), peptic ulcer (9%), or non-ulcer dyspepsia (19%). Orange, alcohol, and coffee precipitated pain more frequently in duodenal ulcer (41%, 50%, and 43% respectively) than in biliary disease (17%, 0%, and 14% respectively). Chilli precipitated pain in one quarter to one half of subjects regardless of diagnosis. Approximately one tenth of all subjects avoided chilli, curry, coffee, and tea because of medical or other advice.

Seroprevalence of antibodies to the hepatitis C virus in Singapore.

The prevalence of antibodies to the hepatitis C virus (anti-HCV) in Singapore was assessed using a recombinant-based enzyme linked immunoassay system. 1004 serum samples were obtained from normal subjects (463), hemodialysis patients (112), hepatitis B virus (HBV) carriers (188), patients with hepatocellular carcinoma (HCC) (58) and patients with non-hepatitis B virus related liver diseases (183). Anti-HCV was found to be positive in 1.7% of healthy subjects, and in 20% of patients on regular hemodialysis. Three percent of HBV carriers were positive for anti-HCV. Twelve percent of patients with acute hepatitis with no known causes and 20% patients with chronic hepatitis with no known causes were positive for anti-HCV. Among patients with cirrhosis for which no known causes were found 33% were positive for anti-HCV. Thirty six percent of patients with HCC not associated with the presence of HBsAg were positive of anti-HCV. None of the patients with known causes of liver disease were positive for anti-HCV.

Horizontal or vertical transmission of hepatitis B virus? A serological survey in family members of hepatitis B carriers in Singapore.

Hepatitis B serology was performed on 270 family members of 78 hepatitis B carriers and hepatitis B e antigen status determined in those found to be HBsAg positive. The mean age of index patients was 38 years (range 3-74) and that of family members was 28 years (range 1-71). 67 family members (25%) were HBsAg positive. The proportions of family members positive for HBsAg and those negative for HBsAg but positive for anti-HBs and/or anti-HBc were 25% and 20% for children, 10% and 68% for spouses, 36% and 26% for siblings and 29% and 55% for parents. For children of index parents the proportions positive for HBsAg and those negative for HBsAg but positive for anti-HBs and/or anti-HBc were similar whether the index patient was the mother (24% and 24%) or the father (26% and 18%). Our results suggest that horizontal transmission is a significant mode of spread of hepatitis B within the family in Singapore.

Hepatitis B vaccination: half dose recombinant DNA hepatitis B vaccine (B-Hepavac II) is as immunogenic as the full recommended dose in healthy adults.

Sixty-seven healthy adult volunteers aged 20-40 years with no previous exposure to hepatitis B virus were randomized to receive either a 10 micrograms or 5 micrograms dose of recombinant DNA hepatitis B (HB) vaccine (B-Hepavac II) intramuscularly at 0, 1 and 6 months. Two months after the third injection 100% of subjects had seroconverted: 97% of the 10 micrograms group and 91% of the 5 micrograms group had antibody to HB surface antigen (anti-HBs) levels greater than 10 iu/L. The geometric mean titres (GMT) of anti-HBs levels at this time were 891 iu/L in the 10 micrograms dose group and 923 iu/L in the 5 micrograms dose group. These differences were not significant. Adverse effects included fever and mild pain at the injection site. The reduced dose of 5 micrograms was as effective as the standard 10 micrograms dose.

The diagnostic yield of upper gastrointestinal endoscopy in the investigation of anaemia.

Computer records of patients endoscoped over a 34-month period were studied to assess the diagnostic yield of gastrointestinal endoscopy in patients with anaemia. Patients with obvious gastrointestinal bleeding and known gastrointestinal pathology were excluded. On hundred and thirty-six patients were endoscoped for anaemia. Eighty-three of them (61%) had iron deficiency anaemia and 53 (39%) had other types of anaemia. The ages of the patients with iron deficiency anaemia (mean 56 years) were significantly lower than those of other anaemias (means 65 years), (p less than 0.003). Patient characteristics were otherwise comparable. There were significant endoscopic findings (ulcers, carcinoma and haemorrhagic or erosive gastritis) in 26 of 83 patients (31%) with iron deficiency anaemia, in 11 of 53 patients with other anaemias (21%) and 37 of 136 patients (27%) combined. Significant endoscopic findings were found in 506 of 2224 patients (23%) endoscoped during this period who were not anaemic, did not have obvious gastrointestinal haemorrhage and were not known to have gastrointestinal diseases. The diagnostic yield for iron deficiency anaemia was significantly higher than for the non anaemic group (p less than 0.05). There was no difference between the diagnostic yields of iron deficiency and other anaemias, other anaemias and the non anaemic group, or total anaemias and the non anaemic group. Gastrointestinal symptoms and history of analgesic or steroid usage did not appear to increase the incidence of gastrointestinal lesions in either iron deficiency anaemia or other anaemias. Twenty-three of 41 patients (56%) who had no cause for anaemia found at the end of all investigations were colonscoped.(ABSTRACT TRUNCATED AT 250 WORDS)

The site of recurrent duodenal ulcer.

The aim of this retrospective study was to determine the site of recurrent duodenal ulcer in relation to the site of the index ulcer. One hundred and thirty-five patients who had recurrent duodenal ulcer after documented healing of an index ulcer were studied. The recurrent ulcer was more likely to occur in the anterior bulb if the index ulcer was anterior (35 of 58 = 60%) than if the index ulcer was not anterior (29 of 77 = 38%, p less than 0.01). However, the likelihood of a recurrent ulcer on the posterior wall of the bulb was not significantly different whether the index ulcer was posterior (11 of 36 = 31%) or not (22 of 99 = 22%, p less than 0.24). Three of 20 patients (15%) who initially presented with bleeding bled again with their recurrent ulcers, compared with eight of 115 patients (7%) who first presented with dyspepsia only (p = 0.39). Thirteen patients were assessed independently by two endoscopists to determine ulcer site. Their assessments concurred for 12 (92%).

Hepatitis B vaccination in chronic renal failure patients undergoing haemodialysis: the immunogenicity of an increased dose of a recombinant DNA hepatitis B vaccine.

Thirty-two patients with end stage renal failure who were on haemodialysis and who had no previous exposure to hepatitis B virus were given four intramuscular injections of 40 micrograms (twice the recommended dose) recombinant DNA hepatitis B vaccine (Engerix B, Smith Kline Biologicals) at 0, 1, 2 and 6 months to determine the immunogenicity of this increased vaccine dose. The ages of these patients ranged from 23-54 years with a mean age of 40 years. There were 11 males and 21 females. Three patients underwent renal transplantation during the course of the study and were assessed separately. Antibody levels above 10 IU/L were noticed in 83% of the remaining 29 patients two months after the final dose with an anti-HBs geometric mean titre (GMT) of 2551 IU/L. The antibody response was 82% four months later although the GMT has fallen to 664 IU/L. Renal transplantation did not appear to affect the anti-HBs response to the above vaccination regime. None of the volunteers developed hepatitis B during the study. Our results were much better than results obtained in studies using twice the recommended doses given three times.

Low-dose cimetidine in the acute treatment of duodenal ulcer. Comparison of a single nocturnal dose regimen with a twice daily regimen.

A 0.5 g daily dose of cimetidine was as effective as a 1 g dose in the acute treatment of duodenal ulcer patients in Hong Kong. The aims of the present study were, first, to determine whether low-dose cimetidine treatment was as effective as standard doses in acute duodenal ulcer treatment of patients in Singapore, and second, to compare a single nocturnal dosage regimen with a twice daily regimen. In this single centre, double-blind, controlled trial, 282 patients with endoscopically proven duodenal ulcer were randomized to receive four weeks' treatment with cimetidine using one of three dosage regimens: (A) 800 mg at night; (B) 400 mg at night; or (C) 400 mg twice daily. Two hundred and forty-seven patients were evaluated. The incidences of healing at four weeks were: (A) 40/80 (50%), (B) 39/88 (44%); and (C) 48/79 (61%); (B vs C: P less than 0.05; A vs C: NS; 95% confidence limits: -5% to 27%; A vs B: NS, 95% confidence limits: -6% to 21%). Of 183 patients who had antral biopsies taken, 176 (96%) had histological gastritis, while 167 (91%) were positive for Helicobacter-like organisms. The occurrence of gastritis or Helicobacter-like organisms had no influence on ulcer healing. A 400 mg dose of cimetidine is therefore suboptimal for the treatment of duodenal ulcer in patients in Singapore. A single nocturnal dosage regimen may be less effective than a twice daily regimen.

Helicobacter pylori and gastritis in patients with peptic ulcer and non-ulcer dyspepsia: ethnic differences in Singapore.

Peptic ulcer occurs with different frequencies in the three main racial groups in Singapore. This study aimed firstly to determine the prevalence of Helicobacter pylori in peptic ulcer and non-ulcer dyspepsia patients of the different races and secondly, to assess the relation between H pylori, histological gastritis, patient diagnosis, and race. Gastric antral biopsy specimens from 1502 patients undergoing gastroduodenoscopy were studied and 892 (59%) were positive for H pylori. H pylori was strongly associated with gastritis: 873 of 1197 (73%) patients with gastritis were positive compared with 19 of 305 (6%) without gastritis (p less than 0.0001). The prevalences of H pylori and gastritis were similar in peptic ulcer patients of different races. Malay patients with non-ulcer dyspepsia, however, were less likely to be positive for H pylori (10 of 46 (22%] or to have antral gastritis (17 of 46 (37%] than Chinese (292 of 605 (48%) were positive for H pylori and 421 of 605 (70%) had gastritis) and Indians (35 of 61 (57%) were H pylori positive and 42 of 61 (69%) had gastritis). Patients with duodenal ulcer were more likely to be positive for H pylori than those with non-ulcer dyspepsia, even when subjects with gastritis were considered separately. While our results do not help to explain the observed racial differences in peptic ulcer frequency it may be that the pathophysiology of non-ulcer dyspepsia is different in the different races in Singapore.

The influence of dialect group on peptic ulcer frequency amongst the Chinese in Singapore.

In Singapore, peptic ulcer is more common amongst Chinese than amongst Malays or Indians. Earlier work has suggested that, amongst female Chinese, Cantonese women are more susceptible to ulcer disease when compared to females of other dialect groups. The aim of the present study was to confirm or refute this possibility. The dialect group distribution of 897 Chinese patients with peptic ulcer (duodenal ulcer 601, gastric ulcer 296) was compared with that of non-ulcer dyspepsia patients and 1602 general medical patients attending the same medical units. The proportion of various dialect groups (including Cantonese) was similar in all patient groups. The proportion of ulcer patients presenting with haemorrhage was also similar in the different dialect groups. We conclude that no major dialect differences exist in peptic ulcer frequency amongst the Chinese in Singapore.

Antibody to herpes simplex virus type 1 in peptic ulcer patients.

It has been postulated that herpes simplex virus type 1 may be a causative factor of duodenal ulcer. Serum antibody titres to herpes simplex virus type 1 in duodenal and gastric ulcer patients were compared with race-, sex- and age-matched controls. No differences in antibody titres could be demonstrated between duodenal ulcer and gastric ulcer patients and their respective controls, between gastric ulcer and duodenal ulcer patients or between acute and convalescent sera in either gastric or duodenal ulcer. Although Chinese are more susceptible to ulcer disease than Malays and Indians, antibody titres were comparable between subjects of different races. The results of this study do not support a causal role for herpes simplex virus in peptic ulcer disease.