Prospective study of biliary strictures to determine the predictors of malignancy

ORIGINAL ARTICLE BACKGROUND: There have been few prospective studies regarding the investigation of biliary strictures, principally because of rapid technological change. The present study was designed to determine the sensitivity of various imaging studies for the detection of biliary strictures. Serum biochemistry and imaging studies were evaluated for their role in distinguishing benign from malignant strictures. METHODS: Thirty-one patients with suspected noncalculus biliary obstruction were enrolled consecutively in the study. A complete biochemical profile, ultrasound, Disida scan and cholangiogram (endoscopic retrograde cholangiopancreatography [ERCP] or percutaneous cholangiogram) were obtained at study entry. Stricture etiology was determined based on cytology, biopsy and/or clinical follow-up at one year. RESULTS: Twenty-nine of 31 patients had biliary strictures, of which 15 were malignant. The mean age of the malignant cohort was 73.9 years versus 53.9 years in the benign cohort (P<0.001). Statistically significant differences between the malignant and benign groups, respectively, were as follows: alanine transaminase 235.2 versus 66.9 U/L (P=0.004), aspartate transaminase 189.8 versus 84.5 U/L (P=0.011), alkaline phosphatase 840.2 versus 361.1 U/L (P=0.002), bilirubin 317.8 versus 22.1 µmol/L (P<0.001) and bile acids 242.5 versus 73.2 µmol/L (P=0.001). Threshold analysis using receiver operative characteristic (ROC) curves demonstrated that a bilirubin level of 75 µmol/L was most predictive of malignant strictures. Intrahepatic duct dilation was present in 93% of malignant strictures versus 36% of benign strictures (P=0.002). Common hepatic duct dilation was less discriminatory (malignant 13.5 versus benign 9.6 mm; P=0.11). Ultrasound was highly sensitive (93%) in the detection of the primary tumour in the bile duct or pancreas, or in the visualization of nodal or liver metastases. In benign disease, ultrasound failed to detect evidence of intrahepatic or extrahepatic biliary dilation in most cases. Disida scans were not able to distinguish between malignant or benign strictures and could not accurately localize the level of obstruction. The sensitivity of Disida scan for the diagnosis of obstruction was 50%. Cholangiographic characterization of strictures revealed an equal distribution of smooth (eight of 13) and irregular (five of 13) strictures in the malignant group. Ten of 13 benign strictures were characterized as smooth. Malignant strictures were significantly longer than benign ones -30.3 versus 9.2 mm (P=0.001). Threshold analysis using ROC curves showed that strictures greater than or equal to 14 mm were predictive of malignancy (sensitivity 78%, specificity 75%, log odds ratio 11.23). CONCLUSIONS: A serum bilirubin level of 75 µmol/L or higher, or a stricture length of greater than 14 mm was highly predictive of malignancy in patients with a biliary stricture. Ultrasound was useful in predicting malignant strictures by detecting either intrahepatic duct dilation or by visualizing the tumour (primary or metastases). Strictures with a 'benign' cholangiographic appearance are frequently malignant. Disida scan did not add additional information. ERCP is necessary to diagnose benign strictures, which tend to be less extensive at presentation. B iliary strictures are a challenging problem for the clinician. By the time that patients with biliary strictures are referred to a specialist, the diagnosis is usually already known or strongly suspected because clinical evaluation and noninvasive investigations alone have a high specificity and sensitivity (1-4). The job of the medical or surgical specialist is not only to confirm the diagnosis of biliary stricture but also, importantly, to define the etiology and the exact anatomic location, which is vital to therapeutic planning. The differentiation between benign and malignant strictures can be difficult but is of obvious importance in regard to prognosis and optimal therapy. Numerous imaging modalities are available for the investigation of biliary strictures, including abdominal ultrasound, computed tomographic (CT) scanning, nuclear imaging, percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP) and most recently magnetic resonance cholangiopancreatography (MRCP). Comparative and descriptive studies in this area are lacking, primarily because rapid technological improvements and developments outdate them. We, therefore, embarked on a prospective descriptive trial with the following aims: · Determine the predictive value of liver enzymes, serum bilirubin, serum bile acids, ultrasound and diethyl-iminodiacetic acid (Disida) nuclear imaging for the presence of malignant biliary strictures. · Measure the ability of ultrasound and nuclear imaging to localize the level of obstruction using direct cholangiography as the gold standard. · Determine the sensitivity of abdominal ultrasound and Disida nuclear scanning for the detection of biliary strictures. · Investigate the utility of various cholangiographic features to distinguish malignant from benign strictures. PATIENTS AND METHODS Patients: All patients with biliary strictures referred to the Division of Gastroenterology at the University of Alberta Hospitals for investigation between January 1, 1995 and December 31, 1995 were prospectively entered into the trial. The inclusion criteria were age 16 years or older and noncalculus biliary obstruction. Patients were excluded if subsequent evaluation did not show a stricture. Ethics committee approval was obtained. sente dans 93 % des sténoses malignes par rapport à 36 % des sténoses béni-gnes (P = 0,002). Une dilatation du canal hépatique commun était moins discriminatoire (13,5 mm en cas de malignité par rapport à 9,6 mm en cas de bénignité, P = 0,11). L'échographie était hautement sensible (93 %) pour déceler la tumeur primaire dans le canal biliaire ou le pancréas, ou pour visualiser les nodules ou les métastases hépatiques. Dans le cas d'une maladie bénigne, l'échogra-phie n'a pas réussi à déceler la présence d'une dilatation biliaire intra-hépa-tique ou extra-hépatique dans la plupart des cas. Les scintigraphies au disida n'ont pas pu différencier les sténoses malignes des sténoses bénignes ou localiser précisément le niveau de l'obstruction. La sensibilité des scintigraphies au disida pour établir un diagnostic d'obstruction était de 50 %. La caractérisation cholangiographique des sténoses a révélé une distribution égale de sténoses lisses (huit sur 13) et irrégulières (cinq sur 13) dans le groupe des sténoses malignes. Dix des 13 sténoses bénignes ont été qualifiées de lisses. Les sténoses malignes étaient nettement plus longues que les sténoses bénignes, soit 30,3 mm par rapport à 9,2 mm (P=0,001). L'analyse des seuils au moyen des courbes ROC a révélé que des sténoses supérieures ou égales à 14 mm étaient un prédicteur de malignité (sensibilité de 78 %, spécificité de 75 %, risque relatif logarithmique de 11,23). CONCLUSIONS : Un niveau de bilirubine sérique de 75 µmol/L ou une longueur de sténose de 14 mm étaient fortement prédictifs de malignité chez les patients atteints d'une sténose biliaire. L'échographie était utile pour prédire les sténoses malignes en décelant soit une dilatation du canal intra-hépatique ou en visualisant la tumeur (primaire ou métastases). Les sténoses d'apparence « bénigne » à la cholangiographie s'avèrent souvent malignes. La scintigraphie au disida n'apportait pas d'informations supplé-mentaires. Une CPRE est nécessaire pour diagnostiquer des sténoses bénignes, qui ont tendance à être moins étendues à l'examen. · Abdominal ultrasound examination with particular attention to intrahepatic biliary dilation, extrahepatic duct calibre, presence or absence of gallbladder and other relevant pathology such as tumour mass or ductal stones. · Disida scan. Patients were examined after a 4 h fast. Opiates were withheld for the proceeding 24 h. In addition to the standard scan, data were collected for deconvolutional analysis to determine hepatic extraction fraction and time activity curve so that the half-life of biliary excretion and time to peak activity could be analyzed. · Cholangiography. ERCP was attempted first in all patients with failures proceeding to PTC. Cefazoline 1 g was administered intravenously 30 to 60 mins before cholangiography. The biliary system was filled as completely as possible using 50% Conray 60 (Mallenchrodt, St Louis, Missouri) contrast injected under low pressure. The information obtained from each cholangiogram included site of stricture, multiplicity, character (smoothly tapered versus irregular or shouldered), stricture(s) length, minimal stricture width, maximal proximal biliary dilation and other information (ampullary mass, primary sclerosing cholangitis, cancer of the pancreas). All data were to be collected within five working days so that the different imaging modalities tested would be comparable. All imaging studies were interpreted by radiologists blinded to the results of the patients' other diagnostic studies. The ERCP data were obtained last so that a biliary stent could be inserted if indicated. The cholangiographic measurements were confirmed by two independent observers. Stricture etiology was defined by cytology or biopsy histology or by clinical outcome after one year. Statistical analysis: Statistical analysis was performed using SPSS. Between-groups differences in mean values of continuous variables were tested by independent samples t tests or by nonparametric Mann-Whitney Rank Sum tests when the distributions were not normal. The differences in frequencies of categorical variables were tested by c 2 test with Yates' correction for continuity or by Fisher's exact test when the expected number of observations per cell was less than five. Associations between continuous variables were assessed by Pearson correlation coefficient. Logistic regression analysis was used to analyze the association of dichotomous outcome variable (malignant versus benign) with continuous and categorical predictor variables. The statistical inferences were based on the level of significance P<0.05. Receiver operating characteristic (ROC) curves were constructed for the biochemical variables. To determine optimal threshold levels for each diagnostic parameter, ROC plots were constructed using the observed true and false positive rates at each potential threshold level. A best fit ROC curve was constructed according to methods published elsewhere (5,6). The threshold value providing the best compromise between true and false positive rates was estimated from the ROC plot. Likelihood ratios were calculated from the fitted ROC curve. RESULTS Thirty-one patients were enrolled in the study. Two patients were excluded -one because he did not have a stricture and one whose suspected stricture was unevaluable because of previous biliary bypass and contraindication for PTC as a result of coagulopathy. Of the remaining 29 patients, 15 were diagnosed with malignant strictures and 14 with benign strictures. Two patients had primary sclerosing cholangitis, both of whom had multiple strictures. Patient demographics and underlying diagnosis are shown i

Endoscopic Perforation Rates at a Canadian University Teaching Hospital

BACKGROUND: Despite advances in training, operative techniques and endoscopic technology, upper and lower endoscopic procedures continue to have potential for intestinal perforation. Perforation rates provided to patients at the time of consent have frequently been derived from historical cohorts and survey datasets

Recognizing immunoglobulin G4-related overlap syndromes in patients with pancreatic and hepatobiliary diseases

The first description of autoimmune pancreatitis and elevated serum immunoglobulin-G4 (IgG4) in 2001 heralded further reports of several related autoimmune diseases with raised IgG4 levels. It is now recognized that a spectrum of overlap syndromes associated with increased IgG4 and biopsy evidence of IgG4-producing plasma cells, which has now been convincingly linked with cholangitis, autoimmune hepatitis, Sjögren’s syndrome, nephritis and retroperitoneal fibrosis. Collectively, this disease cluster is referred to as IgG4-related systemic disease. The importance of making the correct diagnosis is underscored by the management of individuals with IgG4-related systemic disease. In the first instance, patients generally have a dramatic response to immunosuppressive therapy, whereas patients with other forms of cholangitis and pancreatitis do not. Also, surgical management of pancreatic malignancy can be avoided once the correct diagnosis of IgG4-related disease has been made. In the present review, an overview of the current information regarding the role of IgG4 and IgG4-positive cells affecting the biliary system, pancreas and liver is provided

The clinical impact and cost implications of endoscopic ultrasound on the use of endoscopic retrograde cholangiopancreatography in a Canadian university hospital

BACKGROUND: Endoscopic ultrasound (EUS) is a safe alternative to endoscopic retrograde cholangiopancreatography (ERCP) for diagnostic biliary imaging in choledocholithiasis. Evidence linking a decline in diagnostic ERCP with the introduction of EUS in clinical practice is limited

Evaluation of bimodal microstructures in selective-laser-melted and heat-treated Ti-6Al-4V

[Display omitted]•The response of SLM Ti64 to ‘cyclical’ heat treatment strategies was characterised in terms of microstructure and mechanical performance•The number of thermal cycles experienced in a ‘cyclical’ profile heat treatment significantly influences the high-cycle fatigue behaviour•A lamellar microstructure was shown to out-perform a bimodal microstructurein both tensile and high-cycle fatigue testing.As-built, SLM-printed Ti-6Al-4V parts suffer from non-equilibrium, brittle microstructures due to the formation of metastable α’-phase martensite as a result of the printing process. Post-processing heat treatments are required to alleviate residual stress and decompose the martensite into equilibrium phases. Using unconventional ‘cyclical’ heat treatment profiles, it is possible to achieve a bimodal microstructure as opposed to a more typical lamellar microstructure achieved using conventional heat treatment profiles. In the present research, the effect of cyclical heat treatment parameters (maximum temperature, minimum temperature, number of cycles and cooling regime) on the grain morphology, phase composition and mechanical performance (static and dynamic) has been evaluated. Furthermore, a comparison to a typical lamellar microstructure has been completed as a reference

A Randomized Controlled Trial of Four Precolonoscopy Bowel Cleansing Regimens

BACKGROUND: The ideal bowel cleansing regimen for colonoscopy has yet to be determined. OBJECTIVE: To compare the cleansing efficacy, and patient tolerability and safety of four bowel preparation regimens. METHODS: A total of 834 patients undergoing outpatient colonoscopy were randomly assigned to one of four regimens: 4 L polyethylene glycol (PEG); 2 L PEG + 20 mg bisacodyl; 90 mL of sodium phosphate (NaP); or two sachets of a commercially available bowel cleansing solution (PSMC) + 300 mL of magnesium citrate (M). The primary outcome measure was cleansing efficacy, which was scored by blinded endoscopists using the Ottawa Bowel Preparation Scale. Secondary outcome measures were bowel preparation quality according to time of colonoscopy, and patient tolerability and safety. RESULTS: The mean total cleansing score was significantly worse in the NaP group compared with the other three groups (P<0.0001). The mean cleansing scores were worse in patients who underwent morning versus afternoon colonoscopy, a finding that was consistent in all four groups. PSMC + M was the best tolerated regimen. No clinically significant mean changes in creatinine or electrolyte levels were identified, although a significantly higher proportion of patients in the NaP group developed hypokelemia (P<0.0001). CONCLUSIONS: 2 L PEG + 20 mg bisacodyl, or PSMC + M was as efficacious as 4 L PEG and superior to NaP for bowel cleansing. A short interval between the completion of bowel preparation and the start of colonoscopy (ie, ‘runway time’), irrespective of bowel preparation regimen, appeared to be a more important predictor of bowel cleanliness than the cathartic agents used

Prospective Study of Biliary Strictures to Determine the Predictors of Malignancy

BACKGROUND: There have been few prospective studies regarding the investigation of biliary strictures, principally because of rapid technological change. The present study was designed to determine the sensitivity of various imaging studies for the detection of biliary strictures. Serum biochemistry and imaging studies were evaluated for their role in distinguishing benign from malignant strictures

A Prospective Audit of Patient Experiences in Colonoscopy Using the Global Rating Scale: A Cohort of 1187 Patients

BACKGROUND: The Global Rating Scale (GRS) comprehensively evaluates the quality of an endoscopy department, providing a patient-centred framework for service improvement. OBJECTIVE: To assess patient experiences during colonoscopy and identify areas that need service improvement using the GRS. METHODS: Consecutive outpatients undergoing colonoscopy were asked to complete a pre- and postprocedure questionnaire. Questions were based on GRS items and a literature review. The preprocedure questionnaire addressed items such as patient characteristics and information provision. The postprocedure questionnaire contained questions regarding comfort, sedation, the attitude of endoscopy staff and aftercare. RESULTS: The preprocedure questionnaire was completed by 1187 patients, whereas the postprocedure part of the questionnaire was completed by 851 patients (71.9%). Fifty-four per cent of patients were first seen in the outpatient clinic. The indication for colonoscopy was explained to 85% of the patients. Sixty-five per cent of the patients stated that information about the risks of colonoscopy was provided. Sedation was used in 94% of the patients; however, 23% judged the colonoscopy to be more uncomfortable than expected. Ten per cent of patients rated the colonoscopy as (very) uncomfortable. Preliminary results of the colonoscopy were discussed with 87% of patients after the procedure. Twenty-one per cent of the patients left the hospital without knowing how to obtain their final results. Being comfortable while waiting for the procedure (OR 9.93) and a less uncomfortable procedure than expected (OR 2.99) were important determinants of the willingness to return for colonoscopy. CONCLUSIONS: The present study provided evidence supporting the GRS in identifyng service gaps in the quality of patient experiences for colonoscopy in a North American setting. Assessing experiences is useful in identifying areas that need improvement such as the provision of pre- and postprocedure information