Endoscopic ultrasound of the upper gastrointestinal tract and mediastinum: diagnosis and therapy.

Endoscopic ultrasound (EUS) has developed significantly over the last two decades and has had a considerable impact on the imaging and staging of mass lesions within or in close proximity to the gastrointestinal (GI) tract. In conjunction with conventional imaging such as helical computed tomography and magnetic resonance imaging, the indications for EUS include (1) differentiating between benign and malignant lesions of the mediastinum and upper GI tract, (2) staging malignant tumors of the lung, esophagus, stomach, and pancreas prior to surgery or oncological treatment, (3) excluding common bile duct stones before laparoscopic cholecystectomy, thereby avoiding the need for endoscopic retrograde cholangiopancreatography (ERCP) in some patients, and (4) assessing suspected lesions that are either equivocal or not seen on conventional imaging. In recent years, EUS has charted a course similar to that taken by ERCP, evolving from a purely diagnostic modality to one that is interventional and therapeutic. These indications include (5) obtaining a tissue diagnosis by EUS-guided fine-needle aspiration or trucut-type needle biopsy and (6) providing therapy such as coeliac plexus neurolysis and pancreatic pseudocyst drainage--in many cases, more accurately and safely than conventional techniques. Emerging investigational techniques include EUS-guided enteric anastomosis formation and fine-needle injection therapy for malignant disease.

The ryanodine receptor mediates early zymogen activation in pancreatitis.

Acute pancreatitis is characterized by the pathologic activation of zymogens within pancreatic acinar cells. The process requires a rise in cytosolic Ca(2+) from undefined intracellular stores. We hypothesized that zymogen activation is mediated by ryanodine receptor (RYR)-regulated Ca(2+) release, because early zymogen activation takes place in a supranuclear compartment that overlaps in distribution with the RYR. Ca(2+) signals in the basolateral, but not apical, region of acinar cells observed during supraphysiologic agonist stimulation were dependent on RYR Ca(2+) release. Inhibition of RYR or depletion of RYR-sensitive Ca(2+) pools each reduced pathologic zymogen activation in isolated acinar cells, but neither treatment affected amylase secretion. Inhibition of RYR also inhibited zymogen activation in vivo. We propose that Ca(2+) release from the RYR mediates zymogen activation but not enzyme secretion. The findings imply a role for the RYR in acute pancreatitis.

Nutritional support of patients undergoing radiation therapy for head and neck cancer.

Malnutrition plays a key role in the morbidity of head and neck cancer patients receiving surgery, chemotherapy, radiotherapy, or combined-modality therapy. In addition to weight lost prior to the diagnosis of head and neck cancer, the patient may lose an additional 10% of pretherapy body weight during radiotherapy or combined-modality treatment. A reduction of greater than 20% of total body weight results in an increase in toxicity and mortality. Severe toxicity can result in prolonged treatment time, which has been implicated in poor clinical outcome. Early intervention with nutritional supplementation can reduce the chance of inferior outcome in patients at high risk of weight loss. The preferred route of nutritional support for these patients is enteral nutrition. Two commonly used methods for enteral feedings are nasoenteric and percutaneous endoscopic gastrostomy. It is important to take into account the ethical considerations involved in providing long-term nutritional support, particularly for patients with terminal conditions. Nutritional directives are best evaluated through multidisciplinary efforts, including input from the patient as well as members of the nursing, nutritionist, and medical staff.

The substitution of endoscopic ultrasound for endoscopic retrograde cholangio-pancreatography: implications for service development and training.

OBJECTIVES: Choledocholithiasis and other benign conditions of the biliary tree are difficult to define clinically. Endoscopic retrograde cholangio-pancreatography (ERCP) is increasingly being replaced as the investigation of choice by other imaging modalities. The aim of this study was to measure the impact of substituting endoscopic ultrasound (EUS) for ERCP in terms of case throughput and the proportion of therapeutic ERCPs performed. METHODS: Over a 12-month period, cases with a low/medium likelihood for biliary pathology were triaged to EUS rather than ERCP. Data were collected on the proportion of ERCPs performed with diagnostic or therapeutic intent and compared with data from the preceding 12-month period. RESULTS: In the 12 months to April 2001, 518 cases were referred for ERCP; 140 underwent EUS and 378 underwent ERCP. The proportions of diagnostic and therapeutic ERCP were 14% and 86%, respectively. Benign biliary disease represented 33% of all referrals for EUS, and calculi were identified in 6% of these cases. During the preceding year, 637 ERCPs were performed. The proportion of diagnostic (33%) and therapeutic (67%) cases differed from the index year (P < 0.001). CONCLUSIONS: The substitution of EUS for ERCP results in significant quantitative and qualitative change to ERCP practice, which has direct consequences for training and service development.

Detection of occult liver metastases during EUS for staging of malignancies.

BACKGROUND: EUS is commonly used in the staging of GI, thoracic, and other malignancies. Studies suggest EUS can detect occult liver metastases, but the frequency with which this occurs is unknown. METHODS: Records were reviewed for all patients seen during a 3-year period who underwent EUS of the upper-GI tract for staging of known or suspected malignancy. Patients were included if there was histopathologic evidence of malignancy, they had undergone noninvasive liver imaging within 6 weeks of EUS, and liver surveillance was specifically mentioned in the report of the EUS procedure. RESULTS: A total of 222 patients were included. Liver lesions were seen in 27 patients, 17 of whom had an abnormal noninvasive liver imaging test. EUS-guided FNA of the liver was performed in 21 patients and was diagnostic of malignancy in 15 (6.8%), 5 of whom (2.3%) had normal noninvasive imaging. In 6 patients, the EUS-guided FNA result was benign. EUS missed liver lesions in 4 patients known to have abnormalities by other imaging modalities. CONCLUSIONS: EUS can detect occult liver metastases in patients in whom noninvasive hepatic imaging studies are normal, although the frequency at which such lesions are detected is low. Liver surveillance during EUS is worthwhile for patients in whom there is another indication for the procedure; but, at present, EUS should not replace traditional imaging modalities.

Lymphoplasmacytic sclerosing pancreato-cholangitis: a case report and review of the literature.

Autoimmune pancreatitis is a rare but important cause of pancreatitis that is becoming increasingly recognized in the West. Lymphoplasmacytic sclerosing pancreatitis (LPSP) is a benign form of chronic pancreatitis characterized clinically by infrequent attacks of abdominal pain, jaundice, and weight loss, and pathologically by focal or diffuse chronic or lymphoplasmacytic inflammatory infiltrates centered around pancreatic ducts and ductules, accompanied by obliterative phlebitis, acinar atrophy, and interstitial fibrosis. It has been described alone or as a part of the spectrum of autoimmune gallbladder and biliary tract disease, with clinical, radiological, and pathological overlap reported with primary sclerosing cholangitis. It has been described as "primary sclerosing pancreatitis," "sclerosing cholangitis," "non-alcoholic duct destructive chronic pancreatitis," and "autoimmune pancreatitis." We report a case of LPSP that mimicked pancreatic adenocarcinoma and was subsequently treated with a pylorus-preserving Whipple procedure. This may point towards a primary biliary autoimmune process involving the pancreatic duct, causing a benign form of chronic pancreatitis that may be difficult to characterize pre-operatively to avoid surgery. This case typifies the growing awareness of this relatively recently characterized clinical entity, its similar presentation to pancreatic carcinoma, and the importance for LPSP to be included in the differential diagnosis of pancreaticobiliary disease. Finally, we review the literature.