Diagnosis of acute pancreatitis: value of endoscopic sonography

Comparison of ultrasonographic echogenicity and outcome in cats with suspected pancreatitis

OBJECTIVES

The aim of this study was to determine whether ultrasonographic pancreatic echogenicity, especially hypoechogenicity, has an impact on the prognosis of cats with suspected pancreatitis. We hypothesised that cats with a hypoechoic pancreas have a longer duration of hospitalisation, higher treatment costs and a higher mortality rate.

METHODS

This was a retrospective study, which included cats with clinical signs of pancreatitis, a SNAP fPL test result above the reference interval and ultrasonographic abnormalities consistent with pancreatitis. Medical records and follow-up information were retrieved from the local electronic database. Cases were assigned to one of three groups based on pancreatic echogenicity: hypoechoic, hyperechoic or mixed echogenicity. Statistical analysis aimed to assess differences in outcome, ultrasonographic abnormalities, historical features, physical examination findings, laboratory results, concurrent diseases or treatment costs.

RESULTS

Thirty-six (64%) cats with a hypoechoic, seven (13%) with a hyperechoic and 13 (23%) cats with a mixed echoic pancreas were included. Cats with a hypoechoic pancreas had a significantly lower median body weight (P = 0.010) and lower median body condition score (P = 0.004) compared with the other cats. Furthermore, they were presented as being lethargic significantly more often (P = 0.014), were more likely to have a homogeneously enlarged pancreas (P <0.001) and were less likely to have concurrent abnormalities or diseases, such as ultrasonographic enteric abnormalities (P = 0.020), triaditis (P = 0.013) and diabetes mellitus (P = 0.041). However, there was no difference in treatment costs (P = 0.961), duration of hospitalisation (P = 0.898), survival of hospitalisation (P = 0.419) or survival time (P = 0.256) between groups.

CONCLUSIONS AND RELEVANCE

In this study, echogenicity was of no prognostic value in cats with suspected pancreatitis. Cats with a hypoechoic pancreas were not associated with a poorer outcome than cats with a hyperechoic or mixed echoic pancreas.

Evaluating the role of endoscopic ultrasound in pancreatitis

INTRODUCTION

Endoscopic ultrasound (EUS) provides high-resolution images of both pancreatic parenchyma and duct and therefore is an integral component of evaluating and treating patients with pancreatitis and its complications. The development of enhanced EUS imaging techniques and newer EUS-specific accessories has expanded the diagnostic and therapeutic role of EUS in patients with acute and chronic pancreatitis (CP).

AREAS COVERED

This review discusses the current diagnostic and therapeutic role of EUS in acute pancreatitis (AP), CP, and autoimmune pancreatitis (AIP).

EXPERT OPINION

EUS plays a vital role in patients with AP by confirming the presence of common bile duct (CBD) stones in patients with acute biliary pancreatitis and intermediate probability of CBD stones. It plays an important role in the etiological evaluation of patients with idiopathic acute and recurrent pancreatitis. EUS is also an essential modality for diagnosing and managing pancreatico-biliary as well as gastroduodenal complications associated with CP. EUS-guided FNB using newer generation core biopsy needles has made possible accurate diagnosis of AIP by providing tissue samples with preserved architecture.

Radial EUS Examination Can be Helpful in Predicting the Severity of Acute Biliary Pancreatitis

We investigated the utility of noncontrast enhanced endosonography (EUS) in predicting the severity of acute pancreatitis (AP) during the first 72 to 96 h of admission.In total, 187 patients with acute biliary pancreatitis were included. The patients were classified into 2 groups as having severe and mild AP according to the Modified Glasgow scoring and computerized tomography severity index (SI). The 158 cases with mild and 29 cases with severe AP had a similar age and sex distribution.Although none of the cases with mild AP developed morbidity and death, of the cases with severe AP, 16 developed serious morbidities and 5 died. On EUS examination, we looked for parenchymal findings, peripancreatic inflammatory signs, free or loculated fluid collections, and abnormalities of the common bile duct and the pancreatic channel. Statistical analysis indicated a significant relationship between the severity of AP with diffuse parenchymal edema, periparenchymal plastering, and/or diffuse retroperitoneal free fluid accumulation, and peri-pancreatic edema. We also defined an EUSSI and found that the EUSSI had sensitivity of 89.7%, specificity of 84.2%, positive predictivity value (PPV) of 88.9%, negative predictivity value (NPV) of 91.2%, and an accuracy of 87.9% in the differentiation of mild and severe AP. We found that the EUSSI had an accuracy of 72.4%, sensitivity of 75.4%, specificity of 65.1%, PPV of 69.3%, and NPV of 73.1% for determining mortality.Our data suggest that EUS allowed us to accurately predict the severity and mortality in nearly 90% of cases with AP.

Role of endoscopic ultrasound during hospitalization for acute pancreatitis

Endoscopic ultrasound (EUS) is often used to detect the cause of acute pancreatitis (AP) after the acute attack has subsided. The limited data on its role during hospitalization for AP are reviewed here. The ability of EUS to visualize the pancreas and bile duct, the sonographic appearance of the pancreas, correlation of such appearance to clinical outcomes and the impact on AP management are analyzed from studies. The most important indication for EUS appears to be for detection of suspected common bile duct and/or gall bladder stones and microlithiasis. Such an approach might avoid diagnostic endoscopic retrograde cholangio-pancreatography with its known complications. The use of EUS during hospitalization for AP still appears to be infrequent but may become more frequent in future.

Etiology and diagnosis of acute biliary pancreatitis

Establishing a biliary etiology in acute pancreatitis is clinically important because of the potential need for invasive treatment, such as endoscopic retrograde cholangiopancreatography. The etiology of acute biliary pancreatitis (ABP) is multifactorial and complex. Passage of small gallbladder stones or biliary sludge through the ampulla of Vater seems to be important in the pathogenesis of ABP. Other factors, such as anatomical variations associated with an increased biliopancreatic reflux, bile and pancreatic juice exclusion from the duodenum, and genetic factors might contribute to the development of ABP. A diagnosis of a biliary etiology in acute pancreatitis is supported by both laboratory and imaging investigations. An increased serum level of alanine aminotransferase (>1.0 microkat/l) is associated with a high probability of gallstone pancreatitis (positive predictive value 80-90%). Confirmation of choledocholithiasis is most accurately obtained using endoscopic ultrasonography or magnetic resonance cholangiopancreatography. This Review discusses the pathogenesis of ABP and the clinical techniques used to predict and establish a biliary origin in patients with suspected ABP.

The concept of bedside EUS

BACKGROUND

Although the role of bedside endoscopy for the provision of emergent diagnosis and therapy is well known, the concept of bedside EUS requires further validation.

OBJECTIVE

To evaluate the concept of bedside EUS and assess its impact on patient management.

DESIGN

A prospective study.

SETTING

A tertiary-referral center.

PATIENTS

Patients included those with pancreaticobiliary and thoracic disorders who required EUS but who were clinically unstable to be evaluated in the endoscopy suite.

INTERVENTIONS

All procedures were performed by one endosonographer at the patient's bedside by using an EUS cart that was equipped with a therapeutic curvilinear echoendoscope.

MAIN OUTCOME MEASUREMENTS

To evaluate the technical feasibility, safety, and impact of bedside EUS in the clinical management of patients. EUS was considered to have a significant impact if a new diagnosis was established and/or if the findings altered subsequent management.

RESULTS

Within a 3-month period, 6 patients (4 men; median age 56 years; American Society of Anesthesiologists class III/IV) were evaluated in the intensive care unit by using the mobile EUS cart. Procedural indications were the following: drainage of symptomatic pseudocyst (n = 2), evaluate the cause of cholangitis (n = 2), diagnose and treat a suspected postoperative (distal esophagectomy) fluid collection (n = 1), and provide tissue diagnosis in one patient with a pancreatic-head mass, who presented with intrahepatic bleeding. The procedure was technically successful in all 6 patients (100%), and no complications were encountered. Bedside EUS established a diagnosis of choledocholithiasis (n = 1), mediastinal abscess (n = 1), and pancreatic abscess (n = 1) in 3 patients, and ruled out the presence of choledocholithiasis (n = 1) and pancreatic pseudocyst (n = 1) in 2 other patients. Also, by using bedside EUS, transmural drainage of a pancreatic pseudocyst and mediastinal abscess was successfully undertaken in 2 patients. Bedside EUS had an impact on management in all 6 patients (100%): established a new diagnosis (n = 3), precluded the need for an ERCP and/or other interventions (n = 2), and enabled focused endotherapy (n = 3).

LIMITATIONS

Small number of patients; a single endosonographer.

CONCLUSIONS

Bedside EUS is technically feasible, safe, facilitates both diagnosis and therapy, and enables the clinical management of patients who are critically ill.

Management of severe acute pancreatitis

BACKGROUND

Acute pancreatitis is still associated with significant morbidity and mortality. Current management guidelines are sometimes equivocal, particularly in relation to the surgical treatment of severe disease. This review assesses available investigative and treatment strategies to allow the development of a formalized management approach.

METHODS

A literature review of diagnosis, staging and management of acute pancreatitis was performed.

RESULTS AND CONCLUSION

Recent evidence has helped to clarify the roles of computed tomography, endoscopic retrograde cholangiopancreatography, prophylactic antibiotics, enteral feeding and fine-needle aspiration for bacteriology in the management of acute pancreatitis. Despite a relative shortage of prospective randomized trials there has been a significant change in the surgical management of acute pancreatitis over the past 20 years. This change has been away from early aggressive surgical intervention towards more conservative management, except when infected necrosis is confirmed. A formalized approach, with appropriate use of the various non-surgical and surgical options, is feasible in the management of severe acute pancreatitis.

Idiopathic acute recurrent pancreatitis

Acute recurrent pancreatitis (ARP) results most commonly from alcohol abuse or gallstone disease. Initial evaluation fails to detect the cause of ARP in 10-30% of patients, and as a result the diagnosis of "idiopathic" ARP is given. In these patients, a more extensive evaluation including specialized labs, ERCP, endoscopic ultrasound, or magnetic resonance cholangiopancreatography typically leads to a diagnosis of microlithiasis, sphincter of Oddi dysfunction, or pancreas divisum. Less commonly, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatobiliary tumors, or chronic pancreatitis are diagnosed. Determining the etiology is important, as it helps to direct therapy, limits further unnecessary evaluation, and may improve a patient's long term prognosis.

Intraductal papillary tumors of the pancreas: evaluation with endoscopic ultrasonography

BACKGROUND

We retrospectively analyzed the endoscopic ultrasonographic characteristics of intraductal papillary tumors of the pancreas and identified signs indicative of malignant tumors.

METHODS

Twenty-eight patients with intraductal tumors and 38 with other pancreatic cystic lesions underwent endoscopic ultrasonography, conventional ultrasonography, and endoscopic retrograde cholangiopancreatography (ERCP).

RESULTS

Intraductal tumors were classified into three subtypes, and endoscopic ultrasonographic characteristics were assessed. In main duct type tumors, the main pancreatic duct showed a segmental or diffuse moderate-to-marked dilatation, often associated with intraductal nodules. Pancreatic parenchymal atrophy was frequently recognized. Branch duct type tumors consisted of multiple 5 to 20 mm cysts with the appearance of a cluster of grapes. The main duct was mildly dilated or nondilated. Combined type tumors had features of both main duct and branch duct types. Endoscopic ultrasonography (92%) differentiated pancreatic cystic lesions more precisely than ultrasonography (82%) and ERCP (89%). Main duct or combined type tumors, large tumors (> or = 30 mm for branch duct type), marked dilatation of the main pancreatic duct (> or = 10 mm for other types), and mural nodules suggested malignancy. Endoscopic ultrasonography demonstrated these signs more accurately than ultrasonography or ERCP.

CONCLUSION

Endoscopic ultrasonography is useful for diagnosing intraductal papillary tumors, particularly for predicting malignancy.

Endoscopic ultrasonography for diagnosing anomalous pancreaticobiliary junction

BACKGROUND

Anomalous pancreaticobiliary junction (a long common channel) is associated with choledochal cyst or biliary malignancy. We conducted a prospective study to assess the diagnostic value of endoscopic ultrasonography for anomalous pancreaticobiliary junction.

METHODS

In 188 adult patients with pancreatobiliary disease, the length of the common channel demonstrated by endoscopic ultrasonography was compared with that demonstrated by ERCP. In 25 patients with anomalous pancreaticobiliary junction (the common channel > 15 mm on ERCP), diagnostic accuracy of endoscopic ultrasonography for associated pancreatobiliary diseases was evaluated.

RESULTS

On endoscopic ultrasonography, the length of the common channel measured 16.3 +/- 5.8 mm (4 of 27 mm) in patients with anomalous junction; 12 mm or longer in 22 (88%) of 25 patients. In patients with a normal junction, endoscopic ultrasonography demonstrated the channel to be shorter than 7 mm. Endoscopic ultrasonography detected choledochal cyst (in 19 patients), gallstones (in 7), and acute pancreatitis (in 2). This imaging precisely differentiated gallbladder lesions, including carcinoma (4 patients) and mucosal hyperplasia (10 patients) in 14 of 16 patients. Endoscopic ultrasonography could be performed safely in outpatients.

CONCLUSIONS

Endoscopic ultrasonography is useful imaging method for patients with suspected anomalous pancreaticobiliary junction.

Endoscopic ultrasonography for diagnosing choledocholithiasis: a prospective comparative study with ultrasonography and computed tomography

BACKGROUND

We assessed the diagnostic usefulness of endoscopic ultrasonography (EUS) for choledocholithiasis.

METHODS

A prospective series of 155 patients with suspected choledocholithiasis all underwent EUS, conventional ultrasonography, CT, and ERCP. In 142 patients with a clear cholangiogram on ERCP, we analyzed the capability of EUS to image the extrahepatic bile duct and to identify choledocholithiasis, compared with ultrasonography and CT.

RESULTS

No complications were encountered in performing EUS. In 51 patients, ERCP demonstrated bile duct stones, which were confirmed at endoscopic sphincterotomy or surgery. The extrahepatic bile duct was wholly displayed in 96% by EUS, in 60% by ultrasonography, and in 80% by CT. EUS (96%) was more sensitive than ultrasonography (63%) and CT (71%) for detecting choledocholithiasis (p < 0.001). Although ultrasonography and CT were poorly diagnostic for choledocholithiasis in patients with small stones or those with a nondilated common bile duct, EUS was able to accurately detect choledocholithiasis regardless of the size of stones or the diameter of the bile duct. The specificity of EUS (100%) was higher than those of ultrasonography (95%) and CT (97%).

CONCLUSIONS

EUS, a safe imaging procedure, is more accurate than ultrasonography and CT and may be as accurate as ERCP for diagnosing choledocholithiasis.