Intraluminal irradiation for TIPS stenosis: preliminary results in a swine model.

PURPOSE: To evaluate the ability of 32phosphorus intraluminal irradiation to reduce pseudointimal hyperplasia in a transjugular intrahepatic portosystemic shunt (TIPS). MATERIALS AND METHODS: TIPS were successfully placed in 11 swine with normal portal pressures. Six animals received 15.2 Gy intraluminal irradiation to the hepatic parenchyma and venous outflow tract at the time of TIPS placement with use of a NA32P-filled balloon angioplasty catheter. Five control animals underwent TIPS and balloon angioplasty with saline. All animals were followed up for 28 days, at which time percutaneous portography was performed, the animals were killed, and the tissue around the TIPS stent was processed for histologic analysis. Maximum pseudointimal hyperplasia as a percentage of estimated TIPS diameter was calculated for each animal. RESULTS: At the time of euthanasia, all five control TIPS and all but one irradiated TIPS were occluded. Histologic analysis demonstrated considerable variability in the degree of pseudointimal hyperplasia within each TIPS and between animals. No statistically significant difference was found in the maximum pseudointimal hyperplasia, measured as a percentage of stent radius, between control (80.2%+/-17.4%) and irradiated animals (69.2%+/-25.2%). CONCLUSIONS: Irradiation of TIPS with 15.2 Gy 32P delivered at the time of TIPS placement did not significantly improve TIPS patency or reduce the degree of pseudointimal hyperplasia in swine with normal portal pressures.

Molecular forms of gastrin in the circulation of patients with achlorhydria.

BACKGROUND/AIM: To study circulating gastrin profile, both fasting and postprandially, in patients with achlorhydria due to auto-immune atrophic gastritis, comparing these with normal healthy controls. METHODS: Circulating gastrins were measured using three region-specific radio-immunoassays: amidated gastrins (R98), N-terminal G34 (R526) and N-terminal G17 (GP168). Samples were analysed further using gel chromatography. RESULTS: Fasting gastrin concentrations were elevated in achlorhydria as measured using all three antisera: median 714 pmol/l (range 107-5176) in achlorhydria versus 12 pmol/l (2-33) in controls (R98), 343 pmol/l (45-4316) versus 10 pmol/l (5-41) (R526), and 720 pmol/l (14-6000) versus 2 pmol/l (1-10) (GP168). In patients, 47% of gastrin was amidated (95% in controls) and 30% was processed N-terminally only to G71 (4% in controls). Gastrin rose significantly postprandially: 1643 pmol/l (269-7142) in patients versus 24 pmol/l (5-142) in controls (R98), 432 pmol/l (113-4756) versus 15 pmol/l (7-45) (R526) and 2189 pmol/l (304-7150) versus 15 pmol/l (7-45) (GP168). Only 25% was amidated in the patient group (93.5% in controls) and 21% remained as component I (4% in controls). CONCLUSIONS: This abnormal gastrin profile associated with hypergastrinaemia secondary to achlorhydria is consistent with saturation of the enzymes involved in the processing of the pro-hormone, in particular amidation of the C-terminus.

The rise in circulating gastrin with age is due to increases in gastric autoimmunity and Helicobacter pylori infection.

To assess the effect of increasing age on circulating gastrin, we surveyed serum gastrin, Helicobactor pylori seroantibody status and gastric autoimmunity in 366 hospitalized patients aged 15-90 years. Data were subjected to multivariate analysis, using logarithmic transformation to normalize the distribution of gastrin concentrations (presented as geometric means and 95% CIs). The frequency of H. pylori-positive antibody status increased with age from 28% in the second decade to > 70% beyond the fourth decade. Fasting gastrin concentrations rose significantly from 44 ng/l (41-48) in the second decade to 95 ng/l (67-131) by the eighth decade (p = 0.001) in the total group. Twenty-seven patients (6.8% of the total) tested positive for gastric auto-antibodies: 2% of patients in the second decade, rising to 15.9% in the eighth decade. These patients formed a distinct group with respect to circulating gastrin concentrations. Excluding these 27, fasting gastrin concentrations still rose significantly, from 44 ng/l (41-48) in the second decade, to 67 ng/l (50-89) in the eighth decade (p = 0.003) in the remaining 341 patients. Fasting gastrin concentrations were significantly higher in patients who were H. pylori-seropositive (59 ng/l, 54-64 vs. sero-negative 41 ng/l, 37-46) (p = 0.002), and there was no increase in circulating gastrin concentrations with increasing age in either the H. pylori-positive or the H. pylori-negative group. The increase in circulating fasting gastrin observed with increasing age is due to an increased incidence of gastric antibodies associated with auto-immune atrophic gastritis, and an increased incidence of H. pylori infection.

Autoantibodies to gastrin in patients with pernicious anaemia--a novel antibody.

Autoantibodies arise when there is a breakdown in immunological tolerance. Autoantibodies to parietal cells and intrinsic factor are found in autoimmune atrophic gastritis (AAG) and are associated with elevated plasma gastrin. Endogenous gastrin autoantibodies have not been described to date. The aim of this study was to investigate the occurrence of autoantibodies to gastrin. Plasma from 50,000 patients, including more than 2000 with AAG, was tested. Gastrin was measured by radioimmunoassay (RIA) in whole plasma and the presence of autoantibody determined by using a control which omitted assay antibody. The quantity and affinity of gastrin autoantibodies was assessed. Three patients had autoantibodies to gastrin. All three had AAG and pernicious anaemia (PA). The antibodies were of low titre and relatively high affinity. Free circulating plasma gastrin levels were within the normal range, but total gastrin levels were elevated. This is the first description of autoantibodies to endogenous gastrin. The incidence of antibodies to gastrin is low, they are found in association with PA, and they may lead to falsely low measurements of plasma gastrin.

Percutaneous management of hepatic abscess: a perspective by interventional radiologists.

Techniques for treating hepatic abscess have evolved rapidly during the past decade. For many years, the traditional treatment was surgical drainage. The development of modern imaging modalities, such as CT and US, has not only made the diagnosis more certain, but has also introduced a variety of percutaneous treatment options. Pyogenic hepatic abscess is now accepted as a medical/radiologic disease requiring surgical intervention only for correctable offending causes or for failed radiologic evacuation. Drainage via an indwelling catheter has been the traditional method of percutaneous treatment. However, indwelling catheters have disadvantages, including patient discomfort, the nuisance of catheter maintenance, and postprocedural complications. The technique of simple aspiration and intracavitary antibiotics as advocated by McFadzian et al, with excellent results confirmed by Giorgio et al, is a promising alternative to prolonged catheter drainage, and may be the biggest advancement in the management of hepatic abscess in 80 years. Surgeons have recently accepted radiologic drainage; now we need to see if interventional radiologists and surgeons will accept evacuation without indwelling catheter drainage. The role of interventional techniques for nonpyogenic hepatic abscesses will vary considerably. Mortality will still occur in the pyogenic varieties but should be related to underlying disease rather than the abscess itself.

Transjugular intrahepatic portosystemic shunt: midterm clinical and angiographic follow-up.

PURPOSE: To determine the impact of Child class and indication for transjugular intrahepatic portosystemic shunt (TIPS) placement on patient survival and reintervention rate. MATERIALS AND METHODS: Metal stents were used to successfully create single shunts in 63 patients during a 3-year period. Angioplasty and repeated stent placement were used to maintain shunt patency, and patients were followed up clinically and angiographically. Statistical analysis of survival and patency was performed with Kaplan-Meier product-limit survival functions. A Karnofsky performance status score was derived for each follow-up encounter. RESULTS: Early and late mortalities varied with Child class and procedure indications. Thirty-day mortality was 19% overall (12 of 63 patients) and was 33% for Child class C patients (10 of 30 patients). Thirty-day mortality was 31% (four of 13 patients) for patients with ascites and 16% (eight of 50 patients) for those with bleeding. Reintervention was required in 20 of 33 patients and was not predictable on the basis of Child class. CONCLUSION: Child class and indication for procedures are significant predictors of survival but not of the need for reintervention. Ninety-day survivors had uniformly good performance status.

Helicobacter pylori related hypergastrinaemia is the result of a selective increase in gastrin 17.

Helicobacter pylori infection increases the serum concentration of gastrin, and this may be one of the mechanisms by which it predisposes to duodenal ulceration. Different forms of circulating gastrin were studied both basally and postprandially in 13 duodenal ulcer patients before and one month after eradication of H pylori. Three antisera that are specific for particular regions of the gastrin molecules were used. Gel chromatography indicated that > 90% of the circulating gastrin consisted of gastrin (G) 17 and G34 both before and after eradicating the infection. The basal median total immunoreactive gastrin concentration fell from 26 pmol/l (range 11-43) to 19 pmol/l (8-39) (p < 0.05), entirely because of a fall in G17 from 6 pmol/l (< 2.4-25) to < 2.4 pmol/l (< 2.4-23) (p < 0.001). The median (range) basal G34 values were similar before (15 pmol (2-36)) and after (10 pmol (2-30)) eradication. The median total immunoreactive gastrin concentration determined 20 minutes postprandially fell from 59 pmol/l (38-114) to 33 pmol/l (19-88) (p < 0.005), and again this was entirely the result of a fall in G17 from 43 pmol/l (9-95) to 17 pmol/l (< 2.4-52) (p < 0.001). The median postprandial G34 values were similar before (13 pmol/l, range 6-42) and after (15 pmol/l, range 6-30) eradication. Eating stimulated a noticeable rise in G17 but little change in G34, both in the presence and absence of H pylori. The finding that H pylori infection selectively increases G17 explains why the infection causes mainly postprandial hypergastrinaemia. G17 is increased selectively because H pylori predominantly affects the antral mucosa which is the main source of G17 whereas G34 is mainly duodenal in origin. This study also indicates that the increased concentration of gastrin in H pylori infection is the result of an increase in one of the main biologically active forms of the hormone.

Sonographic measurement of abdominal aortic diameter: interobserver variability.

Twenty-eight patients undergoing sonographic evaluation of the abdominal aorta were examined by two separate observers. Three measurements were obtained from each patient: the anteroposterior diameter from an axial image (APA), the right-left diameter from an axial image (RLA), and the anteroposterior diameter from a longitudinal image (APL). Calculation of the interobserver variability gave the following results (in mm): APL, 2.22; APA, 2.53; and RLA, 2.84. The calculated 95% confidence intervals for a single measurement (in mm) were APL, 4.35; APA, 4.94; and RLA, 5.58.

Prospective comparison of plain abdominal radiography with conventional and digital renal tomography in assessing renal extracorporeal shock wave lithotripsy patients.

Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.