198 PALLIATION OF RECURRENT MALIGNANT BILIARY OBSTRUCTION: ARE TWO STENTS BETTER THAN ONE?

P. Dunckley, A.S. Mee. Department of Gastroenterology, The Royal Berkshire Hospital, London Road, Reading, Berkshire, UK

Endoscopic placement of biliary stents across malignant strictures of the common bile duct is effective at palliating symptoms of obstruction. Standard practice is the initial insertion of a single plastic stent. Following this a minority of patients re-present with recurrent jaundice or cholangitis due to stent blockage. The decision as to which type of stent to then place can be difficult: expanding metal stents have a longer survival (mean=240 days) compared to plastic stents (mean=150 days), but are more expensive (£800 and £20 respectively). Without any clinically useful prognostic indicators for survival in these patients, a best guess approach is often used. In some patients it is possible to place a second plastic stent alongside the first.

Between 1990 and 2001 we attempted 31 double-stents in 24 patients with malignant strictures of the common bile duct. All had re-presented with jaundice/cholangitis following the initial insertion of a single plastic stent. Detailed records could not be raised on 6 of these patients. Of the remaining 18 patients (7 women, mean age 81yrs, range 75–84yrs; 11 men, mean age 73.3yrs, range 61–83yrs), 19 (76%) double-stents were successfully placed, 6 (24%) attempted double placements were unsuccessful. 4 patients required more than 1 double-stenting procedure. 16 patients had pancreatic carcinoma, 2 cholangiocarcinoma. The first single stent lasted between 7 and 189 days (mean=83.3 days) before jaundice/cholangitis recurred due to stent blockage. Subsequent double-stents lasted between 24 and 312 days (mean=127.1 days). Using each patient as their own control p<0.21 (NS).

Double-stents in this series lasted 6–7 weeks longer than single stents. The double-stents are placed in more advanced malignant strictures introducing negative bias into these figures. We feel double-stenting, in patients in whom it is technically feasible, may be an alternative to repeated placements of a single stent or an expanding metal stent. This has potential benefits in terms of cost-effectiveness.

199 EVALUATION OF LIQUID-BASED CYTOLOGY (THIN PREP) IN ENDOSCOPIC RETROGRADE BILIARY BRUSH CYTOLOGY

M.K. Shariff, P.A. Smith, M. Lombard, M. Punekar. University Department of Pathology and Department of Gastroenterology, Royal Liverpool University Hospital L7 8XP, UK

Background: Thin Prep™(Cytyc Corporation) is a liquid based cytology system prepared by an automated processor. It offers better specimen retrieval, reduces background material such as blood and polymorph exudates, thus improving cytomorphology and diagnostic accuracy.

Objectives: (1) To compare the performance of endoscopic retrograde biliary brush cytology (ERBC) prepared by Thin Prep (TP) with directly smeared brushings. (2) To demonstrate that variability in diagnostic yield at ERBC can partly depend on the endoscopist.

Methods: 38 ERBC TP bile duct samples from 37 patients with biliary strictures, were compared with 36 ERBC samples from 35 patients proceed by direct smear. In addition, for the TP group, we were interested to see whether technique were consistent between four different endoscopist designated A, B, C, and D. Malignant and suspicious cytology was considered positive and benign as negative. The final diagnosis was based on histology at surgical resection and/or clinical follow up from medical records.

Results: 22 benign, 7 malignant, 4 suspicious, and 3 unsatisfactory results were reported on direct smear with 20 benign, 16 malignant, 2 suspicious and 0 unsatisfactory on Thin Prep. The overall sensitivity of Thin Prep for malignancy (18 of 28 positive, 64%) was significantly greater than direct smear (11 of 33 positive, 33%). The table⇓ compares the difference in sensitivity in Thin Prep group for malignant strictures with regard to different endoscopist doing the ERBC.

Conclusion: (1) TP gives significantly better sensitivity and it reduces the number of unsatisfactory and suspicious results (2) variability in diagnostic yield at ERBC does exist; if this difference can be overcome by improved technique the sensitivity could be further increased.

200 LAPAROSCOPIC CHOLECYSTECTOMY RATES IN IRELAND: RECENT TRENDS

A.N. Keeling, F.E. Murray. Department of Gastroenterology and Clinical Pharmacology, Beaumont Hospital and RCSI, Dublin, Ireland

Background: Studies in other countries have suggested that the overall cholecystectomy rate increased following the introduction of the laparoscopic technique in 1985.

Objective: The aim of this study was to evaluate changes in rates of laparoscopic cholecystectomy (LC) in Ireland, over a 7 year period. We also performed a subset analysis in our 630 bed teaching hospital to determine characteristics of patients, imaging modalities used and indications for surgery.

Methods: Data for cholecystectomies performed in Ireland, in 60 Irish public hospitals, were obtained from the Hospital In Patient Enquiry (HIPE) Scheme, based at the Economic and Social Research Institute (ESRI). The information for the subset analysis in our hospital was retrieved from 139 patient chart reviews, comparing two six month periods, in 1996 and 2000.

Results: Overall, the rate for total cholecystectomies in Ireland (laparoscopic and open), rose by 17% over the 7 year study period. LC rates rose by 45%, with the largest increase of 154% observed in the 0–19 year old age group, with a 121% increase in the 20–24 year old age group. Of note, there was a 25% decline in LC in the 85+ age group. However, despite this overall increase in the number of operations, the total number of deaths (0.59%), remained constant. The rate of open cholecystectomy fell by 37%, with the largest fall of 55% in the 30–34 year old and 40–44 year old age group. The rates of LC also increased in the subset group by 20%, over a 5 year period (1996–2000). A review of procedures in our hospital revealed that relatively ambiguous symptomology became a more frequent indication for LC, rising by 11.5% over the study period. Ultrasonography, as a mode of imaging, remained constant. However, the use of preoperative MRCP increased dramatically, while oral cholecystography use continued to fall. ERCP use, both diagnostic and therapeutic, also increased.

Conclusions: The overall cholecystectomy rate in Ireland has continued to rise in the last 7 years. LC incidence continues to show a sustained rise 16 years after its introduction. Several factors may have contributed to this, including reduced surgical threshold, increased gallstone incidence, reduced unit cost of LC, reduced length of hospital stay and increased patient expectation.

201 PRIORITISING PATIENTS FOR CHOLECYSTECTOMY

K. Somasekar, P.J. Shanker, M.H. Lewis, M.E. Foster (introduced by P.S. Davies). Royal Glamorgan Hospital, Llantrisant, Mid Glamorgan, Wales, UK

Introduction: Emergency admission with gallstone related problems is common among patients awaiting cholecystectomy. By recognising the patients who are prone to recurrent gallstone related problems, it is possible to offer them early surgery.

Aims: To identify the risk factors associated with emergency admissions, due to recurrent gallstone related problems, in patients awaiting cholecystectomy.

Methods: A retrospective analysis was performed of all the patients who underwent elective cholecystectomy by 3 consultants in a district general hospital between 1998–2000. Patients who were admitted as an emergency while awaiting surgery were compared with the remaining patients, with regard to demographics, the specific indication for inclusion in the waiting list, the waiting time, and the ultrasound findings at the time of inclusion in the waiting list.

Results: Of the 211 patients in the study, (mean age 52 years, range 19–82 years), 58 patients (27.4 %) were admitted as an emergency with gallstone related problems while awaiting surgery (Group I). They were compared with the remaining 153 patients(Group II). The mean duration on the waiting list before the patients in Group I were admitted with recurrent symptoms was 19 weeks, as against the mean waiting time for surgery of 56 weeks in Group II patients. The mean duration of symptoms before being listed for surgery was 6.7 months in Group I, compared to 12 months in Group II. Eighteen patients were listed for surgery following an episode of acute cholecystitis in Group I, as against 15 patients in Group II (p<0.001). Ten patients in Group I had a stone in the Hartmann's pouch on ultrasound when they were listed for surgery, compared to 6 patients in Group II (p<0.01).

Conclusions: Duration of the waiting time, by itself, may not affect the incidence of recurrent symptoms due to gallstone disease in patients awaiting cholecystectomy. Patients with symptoms of a shorter duration at the time of initial presentation to the surgeon may be at a higher risk of recurrent gallstone related problems in future. Previous acute cholecystitis and ultrasound evidence of stone in the Hartmann's pouch are important risk factors that predict recurrent gallstone related problems in future.

202 MUCOSAL ADDRESSIN CELL ADHESION MOLECULE-1 (MADCAM-1) AND PODOPLANIN LOCALISATION IN PRIMARY SCLEROSING CHOLANGITIS (PSC) & PRIMARY BILIARY CIRRHOSIS (PBC)

A. Ala¹, R. Standish², K. Khan², M. Stubbs², K. Hillan³, A.P. Dhillon², H.J.F. Hodgson¹. ¹Centre for Hepatology,²Dept of Histopathology, Royal Free & University College Medical School, London, UK;³Genentech Inc, San Francisco, USA

Background: MAdCAM-1 is pivotal in the emigration of lymphocytes expressing a4b7 cell surface integrin from the circulation into tissues of the gut. MAdCAM-1 upregulation has been demonstrated in inflammatory diseases of the liver and appears to contribute to the pathogenesis of ductopenic liver disease. We investigated the hypothesis that MadCAM-1 might play a role in lymphocyte trafficking within lymphatic vasculature in these conditions. Podoplanin is a ∼38-kd membrane glycoproteins of podocytes, reported to be a selective marker of lymphatic endothelium.

Aims: We report the nature and distribution of vessels on which MAdCAM-1 is expressed in cirrhotic ductopenic liver disease.

Methods: Sections of cirrhotic liver explants from nine patients with PSC and seven with PBC were evaluated for expression of MAdCAM-1 & CD34 using an alkaline phosphatase immunohistochemical technique. Sections of normal liver were used as control. Podoplanin expression was evaluated by using immunoperoxidase methodology.

Results: MAdCAM-1 immunoreactivity was not evident in the controls, but present in all cirrhotic sections, localised to septal lymphoid aggregates (either around the aggregate centre or in blood vessel endothelium, thought to be high endothelial venule) as well as the peribiliary capillary plexus (PBP) endothelium (associated with predominantly medium to large bile ducts). Similar staining patterns were seen in both PSC and PBC. Podoplanin was located in vessels with morphological features of lymphatic channels surrounding immediately subjacent to and separate from lymphoid aggregates. These vessels were characterised by a single layer of flattened endothelium without evidence of erythrocytes within their lumen, and were spatially distinct from vessels expressing MadCAM-1.

Conclusion: MAdCAM-1 expression demonstrated within lymphoid aggregates and in PBP vessels identifies presumptive sites of lymphocyte emigration. We have demonstrated MAdCAM-1 immunoreactive in and around lymphoid aggregates, and podoplanin immunostaining shows that these vessels are not lymphatic channels. These studies suggest that the expression of MAdCAM-1 on PBP endothelium may contribute to ductopenic liver disease, providing further evidence to support an immune mediated basis to the pathogenesis of PSC and PBC.

203 THE GENETIC SUSCEPTIBILITY TO NON-HEREDITARY CHRONIC PANCREATITIS: A CASUALTY OF XENOBIOTIC STRESS

S.H. Rahman¹, D. O'Reilly², M. Cartmell², M. Larvin¹, A. Kingsnorth², M.J. McMahon¹. ¹Academic Unit of Surgery, The General Infirmary, Leeds LS1 3EA;²The Post-graduate Medical School, Derriford Hospital, Plymouth, UK

Epidemiological studies have demonstrated a variety of potential environmental and cellular stress related factors that may alter susceptibility to chronic pancreatitis (CP), however a direct causal and mechanistic role has not been established. Impaired detoxification of environmental pollutants may overwhelm cellular oxidative defences leading to lipid membrane damage, protein denaturation and DNA adduct formation.

The aim of this study was to determine the relationship between functional genetic polymorphisms in the anti-oxidant / xenobiotic metabolising enzymes, glutathione-s transferases (GSTM-1, GSTT-1 and GSTP-1), and manganese superoxide dismutase (mitochondrial targeting sequence – MTS), and susceptibility to CP. Genetic susceptibility may in part explain not only the potential benefits of antioxidant therapy, but also the observed twenty-fold increased risk of pancreatic cancer in patients with CP.

In total 103 patients with chronic pancreatitis (71 alcohol induced, 28 IPC and 4HP), and 206 age and sex matched controls were recruited. The prevalence of the GSTT-1 null genotype was significantly under-expressed in CP (11.6 %) compared to healthy controls (24 %, p = 0.006). After stratification for aetiology, this association remained significant in non-alcohol related disease (p<0.05). In contrast to the data with GSTT-1, no significant associations were observed between GSTP-1, GSTM-1, and MnSOD genotypes and susceptibility to CP.

The GSTT-1 functional genotype is associated with an increased susceptibility to CP, whether this is attributable to its phase-II conjugation or anti-oxidant properties remains to be determined.

204 THE GENETIC PRE-DISPOSITION TO SEVERE PANCREATITIS IS ASSOCIATED WITH DISTURBANCES IN GLUTATHIONE REGULATION

S.H. Rahman, K. Ibrahim, M. Larvin, M.J. McMahon. Academic Unit of Surgery, The General Infirmary, Great George Street, Leeds LS1 3EX, UK

Disturbances in glutathione regulation appear central to the pathogenesis of severe acute pancreatitis (AP), by altering cellular integrity and impairing anti-oxidant defences. Individual difference in the efficiency of detoxification of the products of oxygen-derived free radicals may thus be mediated either by altered expression of anti-oxidant enzymes or depletion in cellular glutathione.

We investigated the prevalence of Ala⁹/Val⁹ biallelic functional polymorphism in the mitochondrial targeting sequence (MTS) region of the manganese superoxide dismutase (MnSOD) gene in patients with AP, and examined for interactions with the previously reported polymorphism of the glutathione-S transferse (GST) T-1*A gene associated with severe disease (OR 4.8), and for potential influences on glutathione disturbance (glutathione and transulfuration pathway).

In total, 320 patients with AP (90 severe) and 206 matched healthy controls were recruited. Severity of AP was assessed using the Atlanta criteria, and serial venous blood samples were taken at 24-hr intervals (from pain onset) for C-reactive protein (CRP), γ-glutamyl transpeptidase (γ-GT), alkaline phosphatase (ALP), and alanine transferase (ALT).

A severe attack of AP was associated with an early persistent down-regulation of hepatic function (biliary aetiology) demonstrated by lower plasma γGT (p<0.001), ALT (p<0.001) and ALP (p<0.01), that inversely correlated with CRP (r>-0.3, p<0.001). Although MnSOD polymorphism was not independently associated with severity of AP, among patients of the functional GSTT-1*A genotype the polymorphic MnSOD (AA) genotype was associated with a significantly greater peak CRP (p=0.02), but significantly lower systemic ALT and γ-GT levels (p=0.03) compared to the wild type MnSOD (VV) even after stratifying for biliary aetiology.

Susceptibility to severe inflammatory stress may in part be mediated by differences in the ability to efficiently detoxify reactive oxygen species, through a profound depletion of cellular glutathione as a consequence of altered hepatic function.

205 DISTURBANCE OF GLUTATHIONE REGULATION IN SEVERE ACUTE GALLSTONE PANCREATITIS

S.H. Rahman, M. Larvin, M.J. McMahon. Academic Unit of Surgery, The General Infirmary, Leeds LS1 3EA, UK

Impairment in hepatocellular function often accompanies the severe systemic inflammatory response and multi-organ failure observed in acute pancreatitis (AP). These disturbances may contribute to the inability of the liver to replenish glutathione levels, the depletion of which has been demonstrated to increase cellular susceptibility to inflammatory stress. We therefore sought to determine if severe AP is associated with down-regulation of glutathione metabolism by observing the profile of ALT (transulfuration pathway) and γ-glutamyl transpeptidase in patients with AP of biliary origin.

In 85 patients with gallstone acute pancreatitis, blood samples taken at 24, 48, and 72 hrs from the onset of pain were analysed for ALT, γ-GT, alkaline phosphatase (ALP), and bilirubin, and correlated with (1) the clinical severity (Atlanta criteria), and (2) the positive acute phase protein response (CRP). In patients with a severe attack ALT, γ-GT and ALP but not bilirubin, were significantly lower than those with a mild attack over the entire study period (see table⇓). Plasma ALT demonstrated a strong correlation with γ-GT (24hr: r = 0.52, p < 0.001), and an inverse correlation with CRP (24hr: r = -0.34, p = 0.004).

Depletion of circulating ALT and γ-GT in severe disease is likely to be secondary to a down-regulation of hepatic function, and adversely contribute to the depletion of cellular glutathione.

206 ANALYSIS OF SPATIAL CHANGES IN THE HISTOPATHOLOGY OF PANCREATIC TUMOURS BY IMAGE ANALYSIS

A.J. Sims¹, M.K. Bennett², A. Murray¹. ¹Regional Medical Physics Department,²Department of Histology, Freeman Hospital, Newcastle upon Tyne NE7 7DN, UK

Objective: Pancreatic carcinoma is frequently characterised by a stromal reaction. In this paper, computer image analysis techniques were used to determine whether the histological manifestation of such a reaction can be detected for a group of patients, and for individual tumours.

Study design: Nineteen cases of pancreatic carcinoma treated by pancreaticduodenectomy were studied. Tissue was received fresh and fixed in formalin for 48 hours. The head of the pancreas was serially sliced parallel to the common bile duct and blocks of the tumour were taken which included the surgical resection margins. Blocks retrieved for this study were stained using the sirius red light green method. Five images from the centre and five from the periphery of each tumour were captured using a 4x objective. An image segmentation technique based on colour cluster analysis was used to measure the fractional area of stroma, cell cytoplasm and lumen. Repeatability of the analysis technique was established previously by comparison with manual point counting.

Results: Over all 19 cases, the relative area of tissue occupied by stroma at the periphery of the tumours exceeded that at the centre by an average of 8.4 percentage points (P < 0.01). Correspondingly, the area occupied by cell cytoplasm was on average 7.8 percentage points (P < 0.01) greater at the centre than periphery. No significant difference in luminal area was observed. Measurements from multiple images from each tumour were used to detect significant differences within individual tumours. In 9 cases, the fraction of stroma at the periphery significantly exeeded that at the centre (P < 0.05) with a mean increase in stromal fraction of 17.6”9.4 percentage points. None of the remaining cases had significantly more stromal tissue at the centre that at the periphery.

Conclusions: The computerised image analysis technique used in this study permits colour stained tissue area to be measured rapidly. Over all tumours studied, the fractional percentage of stromal tissue was significantly greater at the periphery than at the centre. Analysis of multiple images per tumour permitted significant differences within 9 of 19 tumours to be detected.

207 FROM GP REFERAL TO DEFINITIVE TREATMENT: A BREAKDOWN OF DELAYS IN THE MANAGEMENT OF PATIENTS WITH PANCREATOBILIARY TUMOURS

S.D. Mansfield, R.M. Charnley¹. South Durham NHS Trust, Bishop Auckland;¹Hepato-Pancreato-Biliary Surgery Unit, Freeman Hospital, Newcastle upon Tyne, UK

The aim of this study was to assess the extent of delays at different stages in the management of patients with pancreatobiliary tumours, from GP referral to definitive treatment at a District General Hospital (DGH) or Hepato-Pancreato-Biliary (HPB) Unit.

The notes of patients with pancreatobiliary malignancy diagnosed at a DGH over a 2 year period (1/9/99 to 1/9/01) were reviewed. Mode of referral, presenting symptoms, investigations performed and treatment were recorded. The time taken at various stages in assessment and treatment was noted, as was delay waiting for investigations.

Of the 42 patients identified, 27 presented with jaundice. 24 were seen in the clinic, 16 were acute GP admissions and 2 were A&E referrals. 7 were referred on to the HPB Unit (see table⇓).

Unacceptable delays occurred in those patients referred to the HPB Unit. If assessment of the majority of patients is to be carried out at HPB Units these waiting times will need to be shortened to conform to National Cancer Plan targets.

208 A PROSPECTIVE STUDY OF THE PABA TEST AND FAECAL ELASTASE-1 IN ASSESSMENT OF PANCREATIC FUNCTION

I. Holbrook, ¹I. Phillips, S.M. Kelly. Depts of Biochemistry and Gastroenterology, York District Hospital;¹Dept of Chemical Pathology, Southampton General Hospital, UK

Assessment of pancreatic exocrine function is part of the routine work-up of patients with persistent diarrhoea/suspected steatorrhoea. Indirect tests of pancreatic function such as the panreolauryl and p-aminobenzoic acid (PABA) tests are widely used but are time consuming and have a poor sensitivity. A simple ELISA kit for determination of faecal pancreatic elastase-1 (FE1) is now available and shown to have a high sensitivity. We performed a prospective study comparing the PABA test to FE1 in patients undergoing assessment of pancreatic exocrine function. All such patients had a PABA test and donated a stool sample for FE1 measurement by an ELISA method (ScheBo Biotech UK).

Results: Paired data were obtained from 44 patients. In 22 patients both tests were normal. In 5 patients with a high clinical index of suspicion for pancreatic disease both tests were low and patients improved with creon. In 14 patients the PABA test was borderline low but the FE1 normal. 9 of these patients had a low index of suspicion for pancreatic disease and did not improve on creon. In the other 5 another cause of diarrhoea was found (e.g. bacterial overgrowth). This suggests that the FE1 was correct in these 14 patients and the PABA results were in fact false lows. 3 patients had a normal PABA but low FE1. 2 of these patients improved with creon suggesting underlying pancreatic insufficiency and that the FE1 was the more accurate test. In one of these patients there was a technical problem with the PABA test giving a false high result. The third patient was a diabetic with severe watery diarrhoea, which can be associated with a false low FE1.

Summary: There was concordance between the two tests in 27 patients (22 normal, 5 low). In 14 patients the PABA was borderline low and FE1 normal, but none of these had clinical evidence of pancreatic disease. FE1 appears a more robust test of pancreatic insufficiency and is a much simpler test. In our unit it has now replaced the PABA test in the assessment of pancreatic exocrine function.