Endoscopic ultrasound: diagnostic and therapeutic applications

Endoscopic ultrasound (EUS) comprises several techniques of performing high-frequency ultrasound via an endoscope placed in the gastrointestinal tract (oesophagus, stomach, duodenum and pancreaticobiliary tree and rectum). It has rapidly become an important tool in the investigation of a variety of lumenal disorders as well as locoregional staging of gastrointestinal malignancies. Needle biopsy of peri-intestinal structures, such as lymph nodes and pancreatic masses, can also be performed under real-time ultrasound control. To date, the utilization of this technology in Australia has been limited by cost constraints and a paucity of training opportunities. EUS continues to be a rapidly growing area in clinical gastroenterology. Recent studies continue to define its role, particularly in the loco-regional staging of a variety of malignancies. In addition, new instruments permit tissue sampling and a variety of therapeutic manoeuvres under direct ultrasound guidance.33; 26-32)

Optimising outcomes in acute pancreatitis

Acute pancreatitis is a common cause for presentation to emergency departments. Common causes in Western societies include biliary pancreatitis and alcohol (the latter in the setting of chronic pancreatitis). Acute pancreatitis also follows endoscopic retrograde pancreatography in 5 to 10% of patients, a group that could potentially benefit from prophylactic treatment. Although episodes of pancreatitis usually run a relatively benign course, up to 20% of patients have more severe disease, and this group has significant morbidity and mortality. Therefore, attempts have been made to identify, at or soon after presentation, those patients likely to have a poor outcome and to channel resources to this group. The mainstay of treatment is aggressive support and monitoring of those patients likely to have a poor outcome. Pharmacotherapy for acute pancreatitis (both prophylactic and in the acute setting) has been generally disappointing. Efforts initially focused on protease inhibitors, of which gabexate shows some promise as a prophylactic agent. Agents that suppress pancreatic secretion have produced disappointing results in human studies. Infection of pancreatic necrosis is associated with high mortality and requires surgical intervention. In view of the seriousness of infected necrosis, the use of prophylactic antibacterials such as carbapenems and quinolones has been advocated in the setting of pancreatic necrosis. Similarly, data are accumulating to support the use of prophylactic antifungal therapy. Recently, it has become apparent that the intense inflammatory response associated with acute pancreatitis is responsible for much of the local and systemic damage. With this realisation, future efforts in pharmacotherapy are likely to focus on suppression or antagonism of pro-inflammatory cytokines and other inflammatory mediators. Similarly, animal studies have demonstrated the importance of oxidative stress in acute pancreatitis, although to date there is a paucity of information regarding the efficacy of antioxidants. Although the clinical course for most patients with acute pancreatitis is mild, severe acute pancreatitis continues to be a clinical challenge, requiring a multidisciplinary approach of physician, intensivist and surgeon.

Neural network analysis of EUS images to differentiate between pancreatic malignancy and pancreatitis

BACKGROUND

The differentiation of focal pancreatitis and pancreatic adenocarcinoma is problematic and often resolved only by pancreaticoduodenectomy. EUS is the most sensitive imaging modality for both conditions, yet ultrasonic criteria for distinguishing the two have not been described and differentiation remains difficult. The aims of this study were to develop a self-learning computer program that can analyze EUS images and differentiate malignancy from pancreatitis, and to compare results obtained with this system with EUS interpretation by experienced endosonographers.

METHODS

Twenty-one patients with pancreatic cancer and 14 with focal pancreatitis were included. The diagnosis was confirmed histologically in all cases and each patient had undergone EUS. A single EUS image from each procedure was used for computer analysis. The results were compared with the EUS diagnosis reported at the actual procedure as well that of an endosonographer who reviewed videotapes of the procedures.

RESULTS

The software program differentiated focal pancreatitis from malignancy with a maximal 89% accuracy. With sensitivity set at 100% for malignancy, the program was 50% specific and accuracy was 80%. Sensitivity and accuracy of the endosonographer's impression at the time of EUS were, respectively, 89% and 85%. A sensitivity of 73% and accuracy of 83% were achieved with blinded interpretation of EUS videotapes.

CONCLUSIONS

Analysis of EUS images with computer software programs is feasible and compares favorably with human interpretation. The application of this technology to EUS and other imaging scenarios could be a useful adjunct to diagnostic endoscopy and warrants further investigation.

A comparison of endoscopic ultrasound, magnetic resonance imaging, and exam under anesthesia for evaluation of Crohn's perianal fistulas

BACKGROUND & AIMS

To determine accuracy of endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) for evaluation of Crohn's disease perianal fistulas.

METHODS

Thirty-four patients with suspected Crohn's disease perianal fistulas were prospectively enrolled in a blinded study comparing EUS, MRI, and examination under anesthesia (EUA). Fistulas were classified according to Parks' criteria, and a consensus gold standard was determined for each patient. Acceptable accuracy was defined as agreement with the consensus gold standard for > or =85% of patients.

RESULTS

Three patients did not undergo MRI; 1 did not undergo EUS or EUA; and consensus could not be reached for 1. Thirty-two patients had 39 fistulas (20 trans-sphincteric, 5 extra-sphincteric, 6 recto-vaginal, 8 others) and 13 abscesses. The accuracy of all 3 modalities was > or =85%: EUS 29 of 32 (91%, confidence interval [CI] 75%-98%), MRI 26 of 30 (87%, CI 69%-96%), and EUA 29 of 32 (91%, CI 75%-98%). Accuracy was 100% when any 2 tests were combined.

CONCLUSIONS

EUS, MRI, and EUA are accurate tests for determining fistula anatomy in patients with perianal Crohn's disease. The optimal approach may be combining any 2 of the 3 methods.

A prospective study of EUS-guided celiac plexus neurolysis for pancreatic cancer pain

BACKGROUND

Celiac plexus neurolysis, a chemical splanchnicectomy of the celiac plexus, is used to treat pain caused by pancreatic cancer. Most commonly, celiac plexus neurolysis is performed percutaneously under CT or fluoroscopic guidance, but can also be performed with EUS. The aim of this study was to prospectively assess the efficacy of EUS celiac plexus neurolysis in the management of pain caused by pancreatic cancer.

METHODS

In this prospective study conducted in a community-based referral hospital, 58 patients with painful and inoperable pancreatic cancer were evaluated at 8 observation points before and after EUS celiac plexus neurolysis for up to 6 months. The following data were collected: age, gender, tumor location, vascular invasion, adjuvant therapy, and laboratory tests including prothrombin time, and complete blood counts were obtained at baseline (before EUS celiac plexus neurolysis); pain scores, morphine use, and adjuvant therapy were assessed at each observation.

RESULTS

Pain scores were lower (p = 0.0001) 2 weeks after EUS celiac plexus neurolysis, an effect that was sustained for 24 weeks when adjusted for morphine use and adjuvant therapy. Forty-five of the 58 patients (78%) experienced a decline in pain scores after EUS celiac plexus neurolysis. Chemotherapy with and without radiation also decreased pain after EUS celiac plexus neurolysis (p = 0.002). Procedure-related transient abdominal pain was noted in 5 patients; there were no major complications.

CONCLUSIONS

EUS celiac plexus neurolysis is safe and controls pain caused by unresectable pancreatic cancer.

Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients

OBJECTIVES

To determine the effect of endoscopic ultrasonography (EUS) on endoscopic drainage of pancreatic pseudocysts and to determine patency with fistula dilation and placement of multiple stents.

PATIENTS AND METHODS

Between September 1995 and January 1999, 19 patients underwent endoscopic drainage of pancreatic pseudocysts, 17 of whom were assessed by EUS before drainage. Radial EUS scanning was used to detect an optimal site of apposition of pseudocyst and gut wall, free of intervening vessels. A fistula was created with a fistulatome, followed by balloon dilation of the fistula tract. Patency was maintained with multiple double pigtail stents. The primary goal of this retrospective study was to determine whether EUS affected the practice of endoscopic drainage of pancreatic pseudocysts.

RESULTS

In 3 patients, drainage was not attempted based on EUS findings. In the other 13 patients (14 pseudocysts), creation of a fistula was successful on 13 occasions, and no immediate complications occurred. However, 1 patient subsequently developed sepsis that required surgery. All other patients were treated with balloon dilation, multiple stents, and antibiotics, with no septic complications. Of 14 pseudocysts (in 13 patients), 13 (93%) resolved.

CONCLUSIONS

Results of EUS may alter management of patients considered for endoscopic drainage of pancreatic pseudocysts. Endoscopic ultrasonography was useful for selecting an optimal and safe drainage site. The combination of balloon dilation, multiple stents, and antibiotics appears to resolve pancreatic pseudocysts without septic complications.

Utility of endoscopic ultrasonography in endoscopic drainage of pancreatic pseudocysts in selected patients

OBJECTIVES

To determine the effect of endoscopic ultrasonography (EUS) on endoscopic drainage of pancreatic pseudocysts and to determine patency with fistula dilation and placement of multiple stents.

PATIENTS AND METHODS

Between September 1995 and January 1999, 19 patients underwent endoscopic drainage of pancreatic pseudocysts, 17 of whom were assessed by EUS before drainage. Radial EUS scanning was used to detect an optimal site of apposition of pseudocyst and gut wall, free of intervening vessels. A fistula was created with a fistulatome, followed by balloon dilation of the fistula tract. Patency was maintained with multiple double pigtail stents. The primary goal of this retrospective study was to determine whether EUS affected the practice of endoscopic drainage of pancreatic pseudocysts.

RESULTS

In 3 patients, drainage was not attempted based on EUS findings. In the other 13 patients (14 pseudocysts), creation of a fistula was successful on 13 occasions, and no immediate complications occurred. However, 1 patient subsequently developed sepsis that required surgery. All other patients were treated with balloon dilation, multiple stents, and antibiotics, with no septic complications. Of 14 pseudocysts (in 13 patients), 13 (93%) resolved.

CONCLUSIONS

Results of EUS may alter management of patients considered for endoscopic drainage of pancreatic pseudocysts. Endoscopic ultrasonography was useful for selecting an optimal and safe drainage site. The combination of balloon dilation, multiple stents, and antibiotics appears to resolve pancreatic pseudocysts without septic complications.

Impact of EUS-guided fine-needle aspiration on lymph node staging in patients with esophageal carcinoma

BACKGROUND

Preoperative identification of lymph node metastases associated with esophageal carcinoma may influence treatment. EUS is the most accurate method for locoregional staging of these tumors. The impact of EUS-guided fine-needle aspiration (EUS-FNA) on lymph node staging in esophageal carcinoma is unclear.

METHODS

From May 1996 to May 1999, 74 patients with esophageal carcinoma underwent preoperative EUS. After October 1998 EUS-guided FNA was performed on nonperitumoral lymph nodes greater than 5 mm in width. The results of EUS with and without FNA were retrospectively reviewed and compared. Final diagnosis was based on surgical results or EUS-guided FNA malignant cytology. Ten of the 74 patients had to be excluded for lack of lymph node stage confirmation. Final diagnosis was obtained in the remaining 64 patients (33 from the EUS only group and 31 from the EUS-FNA group).

RESULTS

The results of EUS versus EUS-FNA for lymph node staging were sensitivity 63% versus 93% (p = 0.01), specificity 81% versus 100% (not significant), and accuracy 70% versus 93% (p = 0.02), respectively. Complications comprised 1 patient who developed self-limited bleeding after dilation that did not preclude completion of the EUS (1%, 95% CI [0%, 7%]).

CONCLUSIONS

EUS-FNA is more sensitive and accurate than EUS alone for preoperative staging of locoregional and celiac lymph nodes associated with esophageal carcinoma. EUS-FNA of nonperitumoral lymph nodes in patients with esophageal carcinoma is safe and should be routinely performed when treatment decisions will be affected by nodal stage.

Initial experience with a steerable, phased vector array ultrasound catheter in the GI tract

BACKGROUND

EUS requires a significant capital outlay. The ability to perform high-resolution phased array scanning and Doppler interrogation by using a catheter that interfaces with a standard US console could increase the accessibility of EUS. Recently, an electronic phased-array US catheter was developed for intracardiac use. To date, this technology has not been applied to the GI tract. The aim of this study is to determine the feasibility and imaging characteristics of a new phased array scanning US catheter in the GI tract.

METHODS

Swine were placed under general anesthesia. This study used a 100 cm, 10F, torquable catheter with 4-way tip deflection to greater than 90 degrees. The catheter tip houses a phased vector array transducer with variable frequency (5.5-10 MHz) and variable focal distance. It has pulsed/color and power Doppler capability. The probe was passed through a therapeutic flexible sigmoidoscope into the upper GI tract. Acoustic coupling was achieved via a condom filled with water or by gastric water infusion. Needle visualization experiments were performed with a second endoscope (also passed per oral) with a standard EUS-guided fine needle aspiration needle.

RESULTS

Acoustic coupling was easily achieved. Resolution of the GI wall into characteristic layers (esophagus 5, stomach 7) was demonstrated. At 5.5 MHz, tissue resolution and Doppler imaging were excellent to greater than 10 cm from the transducer. A 22-gauge EUS-guided fine needle aspiration needle was easily visualized at depth greater than 4 cm. Flow in gastric, hepatic, and pancreatic parenchymal vessels approximately 1 mm diameter was visualized by using power and color Doppler.

CONCLUSIONS

This 10F array US catheter is capable of high-resolution two-dimensional imaging of the gut wall as well as high-quality Doppler imaging. The Doppler capabilities of this equipment may have new GI applications.

Acute extraluminal hemorrhage associated with EUS-guided fine needle aspiration: frequency and clinical significance

BACKGROUND

Complications with EUS-guided fine needle aspiration cytology (EUS-guided FNA) are rare and include perforation, infection, pancreatitis, and intraluminal bleeding. To date, the ultrasound appearance and clinical significance of perilesional bleeding during EUS-guided FNA have not been described. The aim of this study was to analyze the frequency of acute extraluminal hemorrhage associated with EUS-guided FNA.

METHODS

From September 1998 to October 1999 EUS-guided FNA was performed during 227 of 1104 EUS procedures. Patient follow-up and complications were recorded and retrospectively analyzed.

OBSERVATIONS

Three patients were identified with acute extraluminal hemorrhage at the site of the aspiration during EUS (frequency 1.3%: 95% CI [0%, 2.8%]). The bleeding manifested as an expanding echopoor region adjacent to the sampled lesion. No clinically recognizable sequela arose from the bleeding. All patients were treated with a short course of antibiotics and outpatient observation. Preprocedure coagulation and platelet assessment did not predict which patients were at risk for this complication.

CONCLUSION

Acute extraluminal hemorrhage occurring during EUS-guided FNA is a rare complication with a characteristic ultrasound appearance. Recognition of this event might be important to allow the endoscopist to terminate the procedure and thereby minimize the potential for more serious bleeding.

Endoscopic surveillance and ablative therapy for periampullary adenomas

OBJECTIVES

Periampullary adenomas are an increasingly recognized condition, both in those with familial adenomatous polyposis syndromes (FAP) as well as sporadic cases. Endoscopic management has been advocated for these lesions without differentiating between these two patient groups regarding aim of therapy. The aims of this study were to determine the safety and effectiveness of endoscopic surveillance and ablative therapy of periampullary adenomas in patients with both sporadic and FAP-associated lesions.

METHODS

Retrospective analysis of 59 patients with FAP and 32 with sporadic lesions who were all enrolled in a program of endoscopic surveillance and ablative therapy. Median follow-up was 24 months (range, 1-134 months).

RESULTS

Ampullary ablative therapy has resulted in return to normal histology in 44 and 34% of sporadic and FAPassociated lesions, respectively. Complications of endoscopic therapy were mild in 12 patients and severe in 3 patients: the latter category involved one occurrence of asymptomatic duodenal stenosis and one occurrence of postcoagulation syndrome--both after Nd-YAG laser therapy-and necrotizing pancreatitis after ampullary biopsy in one patient. Thirteen patients have been referred for surgical intervention. There has been no mortality and no cases of advanced malignancy missed by endoscopy.

CONCLUSIONS

Endoscopic surveillance and ablative therapy of periampullary lesions is safe and can be effective, although eradication of ampullary tissue requires multiple ablative sessions.

Endoscopic surveillance and ablative therapy for periampullary adenomas

OBJECTIVES

Periampullary adenomas are an increasingly recognized condition, both in those with familial adenomatous polyposis syndromes (FAP) as well as sporadic cases. Endoscopic management has been advocated for these lesions without differentiating between these two patient groups regarding aim of therapy. The aims of this study were to determine the safety and effectiveness of endoscopic surveillance and ablative therapy of periampullary adenomas in patients with both sporadic and FAP-associated lesions.

METHODS

Retrospective analysis of 59 patients with FAP and 32 with sporadic lesions who were all enrolled in a program of endoscopic surveillance and ablative therapy. Median follow-up was 24 months (range, 1-134 months).

RESULTS

Ampullary ablative therapy has resulted in return to normal histology in 44 and 34% of sporadic and FAPassociated lesions, respectively. Complications of endoscopic therapy were mild in 12 patients and severe in 3 patients: the latter category involved one occurrence of asymptomatic duodenal stenosis and one occurrence of postcoagulation syndrome--both after Nd-YAG laser therapy-and necrotizing pancreatitis after ampullary biopsy in one patient. Thirteen patients have been referred for surgical intervention. There has been no mortality and no cases of advanced malignancy missed by endoscopy.

CONCLUSIONS

Endoscopic surveillance and ablative therapy of periampullary lesions is safe and can be effective, although eradication of ampullary tissue requires multiple ablative sessions.

The role of transabdominal ultrasonography, helical computed tomography, and magnetic resonance cholangiopancreatography in diagnosis and management of pancreatic disease

Many technical advances have offered enhanced capabilities in noninvasive imaging of the pancreas. Although these technical advances are impressive, current studies do not always define clearly the benefits that these advances will confer in patient management. A critical overview of these imaging modalities is offered here, with respect to diagnosis and patient management. Outcomes from various studies are summarized for modalities including transabdominal ultrasound, computed tomography, magnetic resonance imaging with and without pancreatography, and positron emission tomography.

Management and long-term prognosis of Dieulafoy lesion

BACKGROUND

The Dieulafoy lesion is an important cause of gastrointestinal (GI) hemorrhage. Optimal treatment and long-term outcome are unknown. This study aimed to characterize the presentation of the Dieulafoy lesion and to summarize the results and report the long-term outcome of endoscopic therapy.

METHODS

Data regarding diagnosis, treatment and outcomes were derived from our GI Bleed Team database, patient records and follow-up correspondence.

RESULTS

Ninety Dieulafoy lesions were identified in 89 patients after a mean of 1.9 endoscopies. Their mean age was 72 years. Thirty-four percent of lesions were extragastric. Median transfusion requirement was 5 units. Two patients exsanguinated and 3 required surgery; all others were initially successfully treated endoscopically (with or without epinephrine injection): heat probe (71 patients), band ligation (3), hemoclip (1), laser (2), bipolar probe (4), sclerotherapy (2) and epinephrine alone (2). Gastric perforation occurred in 1 patient following sclerotherapy. Thirty-day mortality was 13%, 4 related to hemorrhage and 5 related to comorbidity. During median follow-up of 17 months, 34 patients (42%) died. One patient had recurrent bleeding 6 years after operation.

CONCLUSIONS

Dieulafoy lesion is relatively common and often extragastric. Endoscopic therapy is safe and effective. Long-term recurrence was not evident following endoscopic ablation. Follow-up after ablative therapy appears unnecessary.

Interventional treatment of acute and chronic pancreatitis. Endoscopic procedures

The role of therapeutic endoscopy in the treatment of acute and chronic pancreatitis has expanded dramatically over the past 10 years. Drainage of pseudocysts and even organized pancreatic necrosis when localized are becoming commonplace. Other areas in which therapeutic endoscopy has been shown to be efficacious include severe biliary pancreatitis, pancreatic duct disruptions, strictures, and obstructive calculi. Its role in the management of acute recurrent pancreatitis with presumed Oddi's sphincter dysfunction or pancreas divisum continues to be defined. The cost-effectiveness and minimally invasive nature of endoscopic therapy compared with surgery should ensure the continued development of these techniques. More controlled, prospective data are required.

Metabolism of ethanol by rat pancreatic acinar cells

It has been postulated that ethanol-induced pancreatic injury may be mediated by the oxidation of ethanol within the pancreas with secondary toxic metabolic changes, but there is little evidence of pancreatic ethanol oxidation. The aims of this study were to determine whether pancreatic acinar cells metabolize significant amounts of ethanol and, if so, to compare their rate of ethanol oxidation to that of hepatocytes. Cultured rat pancreatic acinar cells and hepatocytes were incubated with 5 to 50 mmol/L carbon 14-labeled ethanol (25 dpm/nmol). Ethanol oxidation was calculated from the production of 14C-labeled acetate that was isolated by Dowex ion-exchange chromatography. Ethanol oxidation by pancreatic acinar cells was demonstrable at all ethanol concentrations tested. At an intoxicating ethanol concentration (50 mmol/L), 14C-labeled acetate production (227+/-20 nmol/10(6) cells/h) approached that of hepatocytes (337+/-61 nmol/10(6) cells/h). Phenanthroline (an inhibitor of classes I through III isoenzymes of alcohol dehydrogenase (ADH)) inhibited pancreatic ethanol oxidation by 90%, but 4-methylpyrazole (a class I and II ADH inhibitor), carbon monoxide (a cytochrome P450 inhibitor), and sodium azide (a catalase inhibitor) had no effect. This study has shown that pancreatic acinar cells oxidize significant amounts of ethanol. At intoxicating concentrations of ethanol, pancreatic acinar cell ethanol oxidation may have the potential to contribute to pancreatic cellular injury. The mechanism appears to involve the class III isoenzyme of ADH.

Management of periampullary adenoma

The periampullary region is the most common site of adenomatous change in the small bowel, particularly in patients with familial adenomatous polyposis (FAP) syndromes. These lesions have been shown to progress to malignancy in a manor analogous to colonic polyps. Following colectomy, the periampullary region is the commonest site of gastrointestinal malignancy in FAP patients. The periampullary region is within easy reach of forward- and side-viewing endoscopes and therefore endoscopic surveillance in FAP patients is both easy and prudent. Furthermore, there is accumulating evidence that endoscopic resection and/or ablation are the treatment of choice for periampullary adenomas. However, the optimal timing of surveillance and best methods of ablation remain to be determined. This paper reviews the literature on the endoscopic management of periampullary adenoma as well as outlining our current approach to this challenging problem.

Periacinar stellate shaped cells in rat pancreas: identification, isolation, and culture

BACKGROUND

The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells (vitamin A storing cells) play a significant role in the development of fibrosis.

AIMS

To determine whether cells resembling hepatic stellate cells are present in rat pancreas, and if so, to compare their number with the number of stellate cells in the liver, and isolate and culture these cells from rat pancreas.

METHODS

Liver and pancreatic sections from chow fed rats were immunostained for desmin, glial fibrillary acidic protein (GFAP), and alpha smooth muscle actin (alpha-SMA). Pancreatic stellate shaped cells were isolated using a Nycodenz gradient, cultured on plastic, and examined by phase contrast and fluorescence microscopy, and by immunostaining for desmin, GFAP, and alpha-SMA.

RESULTS

In both liver and pancreatic sections, stellate shaped cells were observed; these were positive for desmin and GFAP and negative for alpha-SMA. Pancreatic stellate shaped cells had a periacinar distribution. They comprised 3.99% of all pancreatic cells; hepatic stellate cells comprised 7.94% of all hepatic cells. The stellate shaped cells from rat pancreas grew readily in culture. Cells cultured for 24 hours had an angular appearance, contained lipid droplets manifesting positive vitamin A autofluorescence, and stained positively for desmin but negatively for alpha-SMA. At 48 hours, cells were positive for alpha-SMA.

CONCLUSIONS

Cells resembling hepatic stellate cells are present in rat pancreas in a number comparable with that of stellate cells in the liver. These stellate shaped pancreatic cells can be isolated and cultured in vitro.

Cystic fibrosis genotypes and alcoholic pancreatitis

Pancreatitis and pancreatic insufficiency are associated with both cystic fibrosis and alcoholism. The pathogenesis of alcoholic pancreatitis is unknown, but only a minority of alcoholics develop pancreatitis, and it has been suggested that a genetic predisposition may play a role in this disease. Two observations led to the hypothesis that this genetic predisposition could result from mutations in the cystic fibrosis gene. First, the prevalence of cystic fibrosis mutations in the Caucasian population (approximately 5%) is similar to the prevalence of pancreatitis among heavy drinkers. Second, in both diseases, pancreatic duct damage is a prominent feature and has been postulated to be the initial site of injury. Therefore, the aim of this study was to determine whether an increased frequency of mutations in the cystic fibrosis gene occurs in alcoholic pancreatitis. The 15 most common cystic fibrosis mutations in a Caucasian community were sought in 24 subjects with alcoholic pancreatitis. None were homozygous or heterozygous for these mutations. These findings suggest that cystic fibrosis mutations are not a major genetic factor predisposing to pancreatic injury in alcoholics.

Chronic ethanol administration causes oxidative stress in the rat pancreas

There is increasing evidence implicating oxidative stress in the pathogenesis of both acute and chronic pancreatitis. Because ethanol is a major cause of pancreatitis in Western society, the aim of this study was to determine whether chronic ethanol administration results in oxidative stress in the pancreas. Twelve pairs of rats were fed a diet containing ethanol as 36% of calories or an isocaloric control diet for 4 weeks. Ethanol feeding resulted in a 46% increase in pancreatic malondialdehyde (p=0.006). In addition, total pancreatic glutathione was increased by 22% (p=0.005). These biochemical changes occurred in the absence of histologic evidence of inflammation or necrosis, implying that the observed oxidative stress is a primary phenomenon rather than part of an inflammatory response.

Cytochrome P4502E1 is present in rat pancreas and is induced by chronic ethanol administration

BACKGROUND

The mechanisms responsible for the initiation of alcoholic pancreatitis remain elusive. However, there is an increasing body of evidence that reactive oxygen species play a role in both acute and chronic pancreatitis. In the liver, cytochrome P4502E1 (CYP2E1, the inducible ethanol metabolising enzyme) is one of the proposed pathways by which ethanol induces oxidative stress.

AIMS

To determine whether CYP2E1 is present in the pancreas and, if so, whether it is inducible by chronic ethanol feeding.

METHODS

Eighteen male Sprague-Dawley rats were pair fed liquid diets with or without ethanol as 36% of energy for four weeks. CYP2E1 levels were determined by western blotting of microsomal protein from both pancreas and liver. Messenger RNA (mRNA) levels for CYP2E1 were quantified using dot blots of total pancreatic RNA.

RESULTS

CYP2E1 was found in the pancreas. Furthermore, the amount of CYP2E1 was greater in the pancreas of rats fed ethanol compared with controls (mean increase over controls 5.1-fold, 95% confidence intervals 2.4 to 7.7, p < 0.02). In the liver, induction by ethanol of CYP2E1 was similar (mean increase over controls 7.9-fold, 95% confidence intervals 5.2 to 10.6, p < 0.005). Pancreatic mRNA levels for CYP2E1 were similar in ethanol fed and control rats.

CONCLUSIONS

CYP2E1 is present in the rat pancreas and is inducible by chronic ethanol administration. Induction of pancreatic CYP2E1 is not regulated at the mRNA level. The metabolism of ethanol via CYP2E1 may contribute to oxidative stress in the pancreas during chronic ethanol consumption.

Chronic ethanol administration decreases rat pancreatic GP2 content

Postulated mechanisms of alcoholic pancreatitis include (i) zymogen granule fragility facilitating intracellular activation of digestive enzymes and (ii) ductular obstruction by protein plugs. GP2, a pancreatic glycoprotein, stabilizes zymogen granule membranes and is an important constituent of pancreatic protein plugs. Therefore, this study examined the pancreatic content and messenger RNA levels of GP2 after chronic ethanol administration. Rats were fed liquid diets with or without ethanol, for four weeks. GP2 levels in pancreatic homogenates, crude zymogen granules and zymogen granule membrane fractions were assessed by immunoblotting. Messenger RNA levels for GP2 were measured by Northern and dot blotting of pancreatic RNA. Pancreatic GP2 levels were lower in ethanol-fed rats than in controls (GP2 levels expressed as % of control: 38.75 +/- 5.8, p < 0.001 in homogenate; 31.28 +/- 3.5, p < 0.0005 in crude zymogen granules and 22.89 +/- 5.4, p < 0.0005 in zymogen granule membranes). Messenger RNA levels for GP2 were unchanged after ethanol feeding. Chronic ethanol consumption decreases GP2 content of pancreatic homogenate and zymogen granules. This decrease could (i) result from an increased release into pancreatic juice thereby favouring protein plug formation and (ii) impair zymogen granule stability. Both these mechanisms could potentiate pancreatic damage.

Both ethanol and protein deficiency increase messenger RNA levels for pancreatic lithostathine

Both ethanol abuse and protein deficiency are well known associations of chronic pancreatitis. An early event in chronic pancreatitis is the deposition of protein plugs in small pancreatic ducts, leading to ductular obstruction and acinar cell damage. Lithostathine, a pancreatic secretory protein, is a major organic component of protein plugs. The aim of this study was to determine the effect of chronic ethanol administration and dietary protein deficiency, separately and in combination, on messenger RNA (mRNA) levels for pancreatic lithostathine. Male Sprague-Dawley rats were fed in groups of four, for four weeks, protein sufficient and protein deficient diets with or without ethanol. Messenger RNA levels for pancreatic lithostathine were assessed in all four groups. Both ethanol and protein deficiency, separately and in combination, increased mRNA levels for lithostathine. Thus, both chronic ethanol consumption and dietary protein deficiency increase the capacity of the pancreatic acinar cell to synthesize lithostathine.

Fraternal sisters with adult polycystic kidney disease and adenoma of the ampulla of Vater

The cases of two fraternal sisters with symptomatic biliary obstruction due to adenomas of the ampulla of Vater are reported. Both sisters had autosomal dominant adult polycystic kidney disease. There are no previous reports of a familial occurrence of ampullary adenomas in the absence of familial adenomatous polyposis, nor has an association between autosomal dominant polycystic kidney disease and ampullary adenoma been described. The coexistence of both disorders in these sisters raises the possibility of a genetic link between autosomal dominant polycystic kidney disease and ampullary adenoma.

Upper gastrointestinal haemorrhage following coronary artery bypass grafting

BACKGROUND

Upper gastrointestinal (UGI) bleeding is a relatively common and potentially fatal complication of coronary artery bypass graft (CABG) surgery. However, little is known of this problem, including its incidence, predisposing factors and safety of endoscopy in these patients.

AIM

To document the incidence, site, predisposing factors and outcome of UGI bleeding following CABG surgery. Also, to assess the safety of UGI endoscopy in these patients.

METHOD

Retrospective study of UGI haemorrhage following CABG at one institution between 1976 and 1991.

RESULTS

Fifty-five of 10,573 patients (0.5%) suffered a major UGI haemorrhage (as defined by need for transfusion or presence of melaena or haematemesis associated with hypotension). Of 51 patients undergoing endoscopy or laparotomy, 42 (82%) bled from duodenal ulceration. Five patients bled from gastric ulcers and one each from oesophagitis and Mallory Weiss tear. Nine patients underwent endoscopic therapy, which initially arrested haemorrhage in eight patients. However, three patients rebled and required surgery. Eight patients underwent surgery as initial therapy, resulting in an overall surgical rate of 20%. One patient died due to multi system failure following surgery. There were no complications from endoscopy. Patients who bled were more likely to have received inotropic support post-operatively prior to the haemorrhage (p < 0.05) and tended to be older than controls (mean age 65.6 years vs 58.7 years, p < 0.01). Twenty-one of the patients (38%) who bled had a past history of peptic ulceration or dyspepsia compared with 9% of controls (p < 0.001). Seven (12.5%) had previously bled from peptic ulceration. Patients who bled were less likely to have received H2-receptor antagonists in the perioperative period than controls (4% vs 20%, p < 0.05).

CONCLUSION

Upper GI haemorrhage following CABG is relatively frequent. It is usually secondary to duodenal ulceration. Endoscopy is a safe procedure in this patient group. Mortality did not differ between index patients who suffered a UGI haemorrhage and controls undergoing CABG who did not bleed.

Ethanol-induced alterations in messenger RNA levels correlate with glandular content of pancreatic enzymes

Ethanol abuse is a well-known association of pancreatitis. The effects of chronic ethanol consumption on pancreatic digestive and lysosomal enzymes may be relevant to the pathogenesis of alcoholic pancreatitis, because pancreatic enzymes play an important role in the development of pancreatic injury. The aims of this study were to determine the effects of ethanol on gene expression and glandular content of pancreatic digestive enzymes and on gene expression of the lysosomal enzyme cathepsin B (known to be capable of activating trypsinogen). Pancreatic content and mRNA levels for lipase, trypsinogen, and chymotrypsinogen were determined in rats that were pair-fed a nutritionally adequate liquid diet with or without ethanol for 4 weeks. mRNA levels for the lysosomal enzyme cathepsin B were also assessed in this model. Ethanol significantly increased the content of lipase in the pancreas. There was a trend toward an increase in trypsinogen and chymotrypsinogen levels; however, these differences were not statistically significant. mRNA levels for lipase, trypsinogen, and chymotrypsinogen were raised in ethanol-fed rats. Ethanol feeding also increased mRNA levels for the lysosomal enzyme cathepsin B. Furthermore, there was a close, statistically significant correlation between changes in mRNA levels and tissue activities of pancreatic digestive and lysosomal enzymes after ethanol consumption. These results suggest that ethanol increases the capacity of the pancreatic acinar cell to synthesize digestive and lysosomal enzymes, thereby increasing the susceptibility of the gland to enzyme-related injury.

Bacteremia and bacterascites after endoscopic sclerotherapy for bleeding esophageal varices and prevention by intravenous cefotaxime: a randomized trial

Thirty-one patients were randomized during 39 episodes of bleeding to receive either 1 g of intravenous cefotaxime (19 patients) or no antibiotic (20 patients) immediately before emergency endoscopic sclerotherapy. Blood was obtained for culture before and at 5 minutes, 4 hours, and 24 hours after the procedure. Specimens for culture were taken from the endoscope tip and channel, water bottle, and injection needle after sclerotherapy. When ascites was present (5 patients in the antibiotic group, 7 in the control group), fluid was obtained by paracentesis before endoscopy and at 4 and 24 hours. Bacteremia occurred in 1 of 19 patients in the antibiotic group (5.3%), compared with 6 of 19 in the control group (31.6%; p = .04). The cultured organisms were oral flora and usually also contaminated the endoscope and needle. No bacteria were cultured from ascitic fluid in any patient nor was the ascitic fluid white cell count elevated. Clinical infection attributable to sclerotherapy did not develop in any patient. In conclusion, the frequency of bacteremia after endoscopic sclerotherapy for bleeding esophageal varices can be reduced by prophylactic administration of intravenous cefotaxime. However, this may not be clinically relevant, given the absence of bacterascites and infection in this study. These findings do not support the routine use of antibiotics before sclerotherapy.

Anti-neutrophil cytoplasmic antibody: a prognostic indicator in primary sclerosing cholangitis

Considerable variability has been reported in the frequency and specificity of anti-neutrophil cytoplasmic antibody with a perinuclear staining pattern (pANCA) in patients with chronic liver disease, especially in primary sclerosing cholangitis (PSC), and in inflammatory bowel disease. This study examines the presence of pANCA in patients with these disorders, in particular those with PSC complicated by other biliary disease, and also patients who had undergone orthotopic liver transplantation. An indirect immunofluorescent technique was used to measure pANCA with serum diluted 1:20. Ten of 39 (26%) patients with PSC had detectable pANCA, as did two of nine (22%) with autoimmune chronic active hepatitis (AICAH) but none of the 51 patients with other forms of chronic liver disease. The presence of pANCA was significantly more frequent in patients who had PSC with biliary tract complications, in particular calculi (seven of 16 with vs three of 23 without; P = 0.03). Eight of the 12 pANCA-positive patients with PSC or AICAH had undergone hepatic transplantation. This was more likely than in patients with PSC or AICAH who were pANCA negative (10 of 36; P = 0.02). To date, pANCA has been detected after transplantation in four patients with PSC and one with AICAH. In patients with PSC or AICAH, pANCA should be sought as a marker of prognosis.