Diagnosis of annular pancreas by endoscopic ultrasound

Endoscopic Ultrasound in Pancreatic Duct Anomalies

Embryological development of the pancreas is a complex phenomenon and, therefore, it can have multiple developmental aberrations. Fortunately, the majority of these pancreatic ductal anomalies are asymptomatic with no clinical relevance and are incidentally detected during diagnostic cross-sectional imaging or endoscopic retrograde cholangiopancreatography (ERCP) or autopsy. Occasionally, pancreatic duct anomalies can result in symptoms like abdominal pain or recurrent pancreatitis. Also, an accurate pre-operative diagnosis of ductal anomalies can prevent inadvertent duct injury during surgery. Conventionally, ERCP had been used for an accurate diagnosis of pancreatic duct anomalies. However, because it is invasive and associated with a risk of pancreatitis, it has been replaced with magnetic resonance cholangiopancreatography (MRCP). MRCP has demonstrated high sensitivity and specificity for the diagnosis of ductal anomalies, which can be further improved with the use of secretin-enhanced MRCP. Endoscopic ultrasound (EUS) is a new diagnostic and interventional tool in the armamentarium of endoscopists and has demonstrated promising results in the detection of pancreatic duct variations and anomalies. Along with the visualization of the course and configuration of the pancreatic duct, EUS can also visualize changes in the pancreatic parenchyma, thereby helping with an early diagnosis of any co-existent pancreatic disease. Absence of the stack sign and crossed duct sign are important EUS features to diagnose pancreas divisum. EUS can also help with the diagnosis of other congenital ductal anomalies like annular pancreas, ansa pancreatica, and anomalous pancreaticobiliary union, although the published experience is limited.

Mini-probe endoscopic ultrasound for the diagnosis of congenital esophageal or duodenal stenosis

PURPOSE

The usefulness of endoscopic ultrasound (EUS) in pediatric populations has been recently appreciated; however, published studies on mini-probe EUS in the diagnosis of congenital esophageal stenosis (CES) or congenital duodenal stenosis (CDS) in pre-school patients remain scarce. This study aimed to report the utility of mini-probe EUS for the diagnosis of CES or CDS in pre-school patients based on the etiology.

METHODS

We retrospectively reviewed the medical records of pediatric patients with CES or CDS who underwent mini-probe EUS through the stenotic segments at our hospital between December 2006 and December 2021.

RESULTS

Five patients with CES and one with CDS were enrolled. The median age and body weight when EUS was performed were 12.5 months and 8.5 kg, respectively. Hypoechoic lesions were observed on EUS in three patients, which were assessed as cartilage; one patient had no hypoechoic lesion but had a focal thickness of the muscular layer. They were diagnosed with tracheobronchial remnants based on EUS. The full circumferential wall thickness of the esophagus was visualized in one patient with fibromuscular hypertrophy. The histopathological findings confirmed the diagnoses. In the patient with CDS, EUS findings revealed pancreatic parenchyma encircling the stenotic part of the duodenum. The preoperative diagnosis was annular pancreas. The patient underwent duodenoduodenostomy, and intraoperative findings confirmed the diagnosis.

CONCLUSION

Mini-probe EUS can be recommended as a feasible and safe technique for infants and toddlers. It can effectively diagnose CES or CDS based on etiology and can inform treatment strategies for pre-school patients.

The development of zebrafish pancreas affected by deficiency of Hedgehog signaling

The pancreas development depends on complex regulation of several signaling pathways, including the Hedgehog (Hh) signaling via a receptor complex component, Smoothened, which deficiency blocks the Hh signaling. Such a defect in birds and mammals results in an annular pancreas. We showed that in developing zebrafish, the mutation of Smoothened or inhibition of Hh signaling by its antagonist cyclopamine caused developmental defects of internal organs, liver, pancreas, and gut. In particular, the pancreatic primordium was duplicated. The two exocrine pancreatic primordia surround the gut. This phenomenon correlates with a significant reduction of the gut's diameter, causing the annular pancreas phenotype.

Annular pancreas in a 24-year-old woman with persistent abdominal pain

Annular pancreas (AP) is a rare diagnosis in the adult population but can cause significant morbidity if not correctly identified. In adults, the most common symptoms are abdominal pain, nausea and vomiting. While these are not specific to AP, they are important clues to this diagnosis in the right clinical context. We present the case of a 24-year-old woman presenting with a 6-year history of progressive abdominal pain and dyspepsia in the context of an extensive negative workup. Upper gastrointestinal (GI) series and MRI revealed partial duodenal obstruction, concerning for AP. While patients with chronic abdominal pain and vague GI complaints may be diagnosed with functional bowel disorders, it is important to appropriately address the possibility of an underlying structural lesion such as AP. This strategy is not only cost-effective but also saves the patient discomfort associated with unnecessary procedures and allows a timely intervention.

Role of ERCP in Patients With Idiopathic Recurrent Acute Pancreatitis

OPINION STATEMENT

Recurrent acute pancreatitis (RAP) is defined based on the occurrence of two or more episodes of acute pancreatitis. RAP is differentiated from chronic pancreatitis based on the presence of a normal morphological appearance of the pancreas between episodes. RAP can be due to a variety of etiologies including common bile duct stones or sludge, sphincter of Oddi dysfunction (SOD), pancreas divisum (PD), anomalous pancreaticobiliary junction, genetic mutations, and alcohol related. In approximately 30 % of patients, the etiology of RAP is unclear and the term "idiopathic" is used. Endoscopic retrograde cholangiopancreatography (ERCP) can be utilized in both the diagnosis and the initial management of RAP, but it has known limitations and risks. Since gallbladder sludge and SOD account for most cases with RAP, cholecystectomy and, eventually, endoscopic biliary and/or pancreatic sphincterotomy are performed as a part of management. In patients with PD-associated RAP, data from uncontrolled and primarily retrospective studies point toward a benefit from minor papillary endoscopic intervention. However, given the lack of quality data from prospective randomized controlled trials (RCTs), endoscopic management in such patients remains an individualized decision, and RCTs are needed to ascertain its true long-term benefit. Future studies to investigate the role of endoscopic therapy in preventing progression to chronic pancreatitis are needed.

The role of endoscopic retrograde cholangiopancreatography in patients with pancreatic disease

Given the significant risk of pancreatitis and the advent of high-fidelity diagnostic techniques, ERCP is now reserved as a therapeutic procedure for those with pancreatic disease. Early ERCP benefits those with gallstone pancreatitis who present with or develop cholangitis or biliary obstruction. Among those with idiopathic pancreatitis, ERCP may be used to confirm and treat SOD, microlithiasis, and structural anomalies, including pancreas divisum. Pancreatic endotherapy is a consideration to decrease pain in those with pancreatic duct obstruction, although surgical decompression may be more durable, particularly in those with severe disease. Pancreatic duct leaks may respond to endoscopic drainage, but optimal therapy is achieved if a bridging stent can be placed. Finally, using a wire-guided technique and pancreatic duct stents in high-risk patients, particularly in cases of suspected SOD, may minimize the risk of post-ERCP pancreatitis.

Annular pancreas intra operatively discovered: a case report

Annular pancreas is a rare congenital abnormality. This entity can rarely be symptomatic. Patients can present with gastrointestinal obstruction or acute pancreatitis. We report a case with a rich iconography, of an annular pancreas discovered intraoperatively. A 46-year-old woman was operated with the diagnosis of acute cholecystitis with common bile duct stones. At operation, a strip of pancreatic tissue (2 cm) completely encircled the second duodenum. Open cholecytectomy with choledocotomy and stones extractionwas done. Postoperatively, she developed an acute pancreatitis. The post-operative cholangiography showed the annular duct surrounding the second duodenum. Annular pancreas is rare. Symptoms may occur in newborn children. In adults, annular pancreas discovering is radiological or intra operatively.

Development and congenital anomalies of the pancreas

Understanding how the pancreas develops is essential to understand the pathogenesis of congenital pancreatic anomalies. Recent studies have shown the advantages of investigating the development of frogs, mice, and chickens for understanding early embryonic development of the pancreas and congenital anomalies, such as choledochal cysts, anomalous pancreaticobiliary junction, annular pancreas, and pancreas divisum. These anomalies arise from failure of complete rotation and fusion during embryogenesis. There are many theories in the etiology of congenital anomalies of the pancreas. We review pancreas development in humans and other vertebrates. In addition, we attempt to clarify how developmental failure is related to congenital pancreatic anomalies.

Annular pancreas in an adult managed by laparobotic surgery: a case report

Annular pancreas in an adult is an uncommon and infrequently reported anomaly which is characterized by the presence of ectopic pancreatic tissue surrounding the descending part of the duodenum. It is one of the few congenital anomalies of the gastrointestinal tract, which can manifest with symptoms late in life (Ravitch and Woods in Ann Surg 132:1116-1127, 1950). In adults, the factors initiating symptoms are recurrent pancreatitis, duodenal stenosis at the site of the annulus, or duodenal or gastric ulceration (Morrell and Keynes in Br J Surg 57:814-816, 1970). Operative management of these cases involves bypassing the obstructed duodenum. Duodenoduodenostomy is routinely performed in neonates and children. We report a case of annular pancreas in a 55-year-old male that was successfully treated with robotic duodenoduodenostomy.

Endoscopic ultrasonography for evaluating patients with recurrent pancreatitis

Acute recurrent pancreatitis (ARP) is still a complex diagnostic and therapeutic challenge in clinical practice. In up to 30% of cases of ARP, it is not possible to establish the etiology of the disease. In the other 70%, many factors play an etiological role in ARP: microlithiasis, sphincter of Oddi dysfunction (SOD), pancreas divisum, hereditary pancreatitis, cystic fibrosis, a choledochocele, annular pancreas, an anomalous pancreatobiliary junction, pancreatic tumors or chronic pancreatitis are diagnosed. EUS should be useful in ARP as it is sensitive for diagnosing bile duct stones, gallbladder sludge, pancreatic lesions, ductal abnormalities and chronic pancreatitis. Endoscopic ultrasound (EUS) appears to be diagnostic in the majority of patients with previously unexplained pancreatitis, and offers an alternative to endoscopic retrograde cholangiopancreatography (ERCP) as the initial diagnostic test in patients with ARP.

Review of idiopathic pancreatitis

Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate the cause in over 80% of cases. This review examines the multitude of etiologies of what were once labeled idiopathic pancreatitis and provides the current evidence on each. This review begins with a background review of the current epidemiology of idiopathic pancreatitis prior to discussion of various etiologies. Etiologies of medications, infections, toxins, autoimmune disorders, vascular causes, and anatomic and functional causes are explored in detail. We conclude with management of true idiopathic pancreatitis and a summary of the various etiologic agents. Throughout this review, areas of controversies are highlighted.

EUS features of annular pancreas (with video)

BACKGROUND

An annular pancreas is a rare congenital anomaly that results in a band of pancreatic tissue, either partially or completely encircling the duodenum.

OBJECTIVES

In patients referred for an upper-GI (UGI) EUS (1) to determine the prevalence of an annular pancreas identified by EUS versus CT and (2) to describe the EUS features of an annular pancreas.

DESIGN

After review of UGI EUS procedures from January 1, 2000, through June 1, 2006, we conducted a retrospective review of EUS annular pancreas images to identify characteristic EUS features.

PATIENTS

This is the largest report describing the EUS findings in 5 patients.

RESULTS

Of 9776 patients undergoing UGI EUS, 5 patients (0.05%) (2 men; median age, 64 years; range, 44-69 years) were found to have an annular pancreas. EUS detected a band of pancreatic tissue that encircled the duodenum by 360 degrees (n = 3), 270 degrees (n = 1), or 180 degrees (n = 1). Within this band of tissue, the pancreatic duct was identified in 4 of 5 patients. The ductal and parenchymal features within the annular band were identical to those within the remaining pancreas in all patients. None of the patients had hypoechoic ventral anlage.

LIMITATIONS

Whereas, firm EUS criteria of an annular pancreas cannot be established based on 5 patients, certain features may prove useful for diagnosis.

CONCLUSIONS

Although a diagnosis of an annular pancreas is rare, it should be considered in situations when a patient with possible associated symptoms has a normal CT.

Three-dimensional computed tomography pancreatography of an annular pancreas with special reference to embryogenesis

OBJECTIVES

Several hypotheses have been proposed to explain the embryogenesis of an annular pancreas. Three-dimensional (3D) imaging of the annular pancreas may be useful to elucidate the embryogenesis. The aim of this case report is to clarify the pancreatic ducts in the annular pancreas by 3D computed tomography pancreatography (3D-CTP), stereographically.

METHODS

Three-dimensional CTP under endoscopic retrograde pancreatography using a balloon catheter was performed with a helical CT scanner. Three-dimensional images of the pancreatic duct were obtained with simple threshold, shaped surface display.

RESULTS

Wirsung duct that surrounds the ventral side of the descending portion of the duodenum and Santorini duct that surrounds the dorsal side of the descending portion of the duodenum were reconstructed by 3D-CTP, stereographically, and the presence of an annular pancreas was confirmed. These findings suggest that the formation of the annular pancreas in the current case may be attributable not only to abnormal development of the right lobe of the ventral pancreatic bud, but also to overgrowth of the dorsal pancreatic bud toward the ventral aspect of the duodenum or excessive rotation of the duodenum following fusion of the ventral bud to the dorsal bud.

CONCLUSION

Three-dimensional CTP is expected to contribute usefully toward clarifying the embryogenesis of an annular pancreas.

A case of annular pancreas in a male adult

Annular pancreas is a rare congenital anomaly, which consists of a ring of pancreatic tissue partially or completely encircling the descending portion of the duodenum. We reported a case of symptomatic annular pancreas in a 40 year old man admitted to our hospital complaining of abdominal pain, nausea and vomiting without body weight loss in January 2000. The patient underwent laparoscopic cholecystectomy for acalculous cholecystitis in September 1996. Initially, he was diagnosed with duodenal stenosis due to a duodenal ulcer scar, but laboratory data showed no abnormalities. His symptoms did not improve with medication or endoscopic balloon dilatation. Duodenograpy revealed a narrow segment with a smooth mucosal surface in the 2nd portion of the duodenal loop in the duodenum, and a computed tomography (CT) scan demonstrated a thickened pancreas head around this narrow segment. We were therefore able to diagnose annular pancreas. A duodeno-duodenostomy was performed in March 2000. The patient's postoperative course was uneventful, and he was discharged from our hospital on the 19th postoperative day. Although define diagnosis of annular pancreas is frequently made at laparotomy, the development of a recurrent imaging modality might assist in the preoperative diagnosis.

Idiopathic acute pancreatitis

After routine investigations, including a thorough history, routine laboratory study, and noninvasive imaging with transcutaneous ultrasonogram, 10% to 25% of cases of acute pancreatitis have no readily identifiable cause and are termed idiopathic. But modern medicine has made notable advances in uncovering various causes of acute pancreatitis, and several new diagnostic tools that allow clinicians to less invasively approach the patient without sacrificing the diagnostic yield have been introduced. By being knowledgeable of these new changes and by their proper use in a proper circumstances, clinicians will be able to find the cause more accurately and earlier. This better management will not only improve the well-being of the patients but also reduce the number of "true" idiopathic acute pancreatitis to a minimum.

Symptomatic adult annular pancreas

Annular pancreas is most often found in neonates and infants younger than 1 year of age. Annular pancreas in adults is rare and clinically identifiable when symptomatic. Upper gastrointestinal radiography and surgical confirmation were the most common methods for diagnosing annular pancreas in the 1950s to 1980s. However, the revolution in image modalities has enabled preoperative diagnosis in the last 20 years. Many surgical methods have also been developed, and the one used depends on the presentation and extent of the pancreas annulus. We report two cases of symptomatic adult annular pancreas at Chang Gung Memorial Hospital in Taiwan.

Annular Pancreas in the Adult: Two Case Reports and Review of More than a Century of Literature

This paper brings the diagnosis and treatment of this interesting yet infrequent condition to contemporary standards through an assessment of past literature and a re-evaluation of the problem in view of technological advances. Two cases of annular pancreas are cited with a review of the last 183 years of literature. Only 100 cases, however, were reported in enough detail to examine outcomes in general and to arrive at a reasonable conclusion in terms of recommendations for diagnosis and operative intervention in adult annular pancreas. Two observations are brought to light. Despite all present diagnostic tools including endoscopic retrograde cholangiopancreatography diagnosis at best is made in only 60 per cent of patients preoperatively. Intraoperative expertise remains the best diagnostic modality available to date. Enteroenterostomy seems to be the intervention of choice for a multitude of anatomic and physiologic reasons and with a wide array of surgical options available when additional factors need to be addressed.

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.