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GREGORY G. GINSBERG, MD UNIVERSITY OF PENNSYLVANIA PHILADELPHIA, PENNSYLVANIA

NUZHAT A. AHMAD, MD UNIVERSITY OF PENNSYLVANIA PHILADELPHIA, PENNSYLVANIA

An innovative information, education, and management company 6900 Grove Road • Thorofare, NJ 08086

Copyright © 2006 by SLACK Incorporated

ISBN 10: 1-55642-694-1 ISBN 13: 9781556426940

All rights reserved. No part of this book may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without written permission from the publisher, except for brief quotations embodied in critical articles and reviews.

The procedures and practices described in this book should be implemented in a manner consistent with the professional standards set for the circumstances that apply in each specific situation. Every effort has been made to confirm the accuracy of the information presented and to correctly relate generally accepted practices. The authors, editor, and publisher cannot accept responsibility for errors or exclusions or for the outcome of the material presented herein. There is no expressed or implied warranty of this book or information imparted by it.

Care has been taken to ensure that drug selection and dosages are in accordance with currently accepted/recommended practice. Due to continuing research, changes in government policy and regulations, and various effects of drug reactions and interactions, it is recommended that the reader carefully review all materials and literature provided for each drug, especially those that are new or not frequently used.

Any review or mention of specific companies or products is not intended as an endorsement by the author or publisher.

Library of Congress Cataloging-in-Publication Data The clinician’s guide to pancreaticobiliary disorders / edited by Gregory Ginsberg, Nuzhat Ahmad. p. ; cm.

Includes bibliographical references and index.

ISBN 1-55642-694-1 (alk. paper) 1. Pancreas--Diseases. 2. Biliary tract--Diseases.

[DNLM: 1. Biliary Tract Diseases. 2. Pancreatic Diseases. WI 700 C64117 2006] I. Ginsberg, Gregory G. II. Ahmad, Nuzhat.

RC587.C55 2006 616.3’6--dc22 2005022427 Printed in the United States of America.

Published by:

SLACK Incorporated 6900 Grove Road Thorofare, NJ 08086 USA Telephone: 856-848-1000 Fax: 856-853-5991 www.slackbooks.com

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DEDICATION I dedicate this book to my mother Geraldine McDonnell Ginsberg, always a lady, who schooled me in humor and humility. In her personal struggle with chronic illness she exemplified strong will, perseverance, and grace.

G.G.G. Dedicated to Professor Abdus Salam: Pakistani Nobel Laureate in Physics 1979— for leading by example.

N.A.A.

CONTENTS Dedication ................................................................................................................v Acknowledgements ....................................................................................................ix About the Editors .....................................................................................................xi Contributing Authors ............................................................................................ xiii Preface .................................................................................................................... xv Chapter 1:

Development and Function of the Pancreas, Bile Duct, and Gallbladder .................................................................................1 Binita M. Kamath, MBBChir; Raman R. Sreedharan, MD; Petar Mamula, MD

Chapter 2:

Gallstones and Gallbladder Disorders .............................................21 Ann Marie Joyce, MD; William B. Long, MD

Chapter 3:

Choledocholithiasis ..........................................................................47 Eric Goldberg, MD; Peter Darwin, MD

Chapter 4:

Bile Duct Injuries ...........................................................................69 Janak N. Shah, MD

Chapter 5:

Ampullary Disorders ......................................................................91 William B. Silverman, MD, FACG

Chapter 6:

Cholangiocarcinoma ......................................................................103 Patrick R. Pfau, MD

Chapter 7:

Infections of the Biliary System ....................................................121 Faten N. Aberra, MD, MSCE

Chapter 8:

Acute Pancreatitis .........................................................................147 John Horwhat, MD; Paul Jowell, MD

Chapter 9:

Chronic Pancreatitis .....................................................................179 Tyler Stevens, MD; Darwin L. Conwell, MD

Chapter 10: Pancreatic Ductal Complications .................................................217 Ali Fazel, MD Chapter 11: Solid Pancreatic Tumor..................................................................239 Shyam Varadarajulu, MD; Mohamad A. Eloubeidi, MD, MHS, FACP, FACG Color Atlas Chapter 12: Pancreatic Cystic Lesions ...............................................................257 David G. Forcione, MD; Brenna C. Bounds, MD

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Contents

Chapter 13: Surgical Approaches to Pancreatic Cancer.................................... 287 Giorgos C. Karakousis, MD; Francis R. Spitz, MD Chapter 14: Biliary Tract Surgery .................................................................... 297 Rachel Rapaport Kelz, MD, MSCE; Jon B. Morris, MD Chapter 15: Imaging of the Pancreatobiliary System Using Endoscopic Ultrasound.................................................................. 311 Nuzhat A. Ahmad, MD Chapter 16: Magnetic Resonance Imaging/Magnetic Resonance ....................327 Cholangiopancreatography of the Pancreatobiliary System Wendy C. Hsu, MD; Evan S. Siegelman, MD Chapter 17

Pancreaticobiliary Diseases: The Role of the Interventional Radiologist ...................................................................................353 Richard Shlansky-Goldberg, MD; Aalpen Patel, MD

Index.....................................................................................................................367

ACKNOWLEDGMENTS For their support and inspiration we wish to acknowledge our parents and teachers, our respective spouses and kids, colleagues and students, and most certainly our patients. We are grateful to the contributing authors for their time and dedication devoted to developing a text that will benefit countless clinicians and patients.

ABOUT THE EDITORS Gregory G. Ginsberg, MD is Professor of Medicine at the University of Pennsylvania School of Medicine, Gastroenterology Division, and Executive Director of Endoscopic Services at the University of Pennsylvania Health Systems. A graduate of Lafayette College, Easton, PA and Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA, he completed Internal Medicine and Gastroenterology training at Georgetown University Medical Center, Washington, DC. Dr. Ginsberg’s clinical practice and research have focused on the development of new techniques and the evaluation of new technologies as they apply to endoluminal management disorders of the digestive system. Outside of his professional activity, he finds fulfillment with his wife, Jane, and four daughters, Jenny, Kathleen, Elizabeth, and Meg. Nuzhat A. Ahmad, MD is an Assistant Professor of Medicine at the University of Pennsylvania School of Medicine, Gastroenterology Division, and Associate Director of Endoscopic Services at the University of Pennsylvania Health Systems. She is also the chief of Gastroenterology at the Philadelphia VA Medical Center.

CONTRIBUTING AUTHORS Faten Aberra, MD, MSCE Instructor of Medicine Division of Gastroenterology Hospital of the University of Pennsylvania Philadelphia, PA Brenna Casey Bounds, MD Instructor in Medicine Harvard Medical School Director of Endoscopic Training Massachusetts General Hospital Boston, MA Darwin L. Conwell, MD Department of Gastroenterology and Hepatology The Cleveland Clinic Foundation Cleveland, OH Peter Darwin, MD Associate Professor of Medicine Director of Gastrointestinal Endoscopy University of Maryland Medical School Baltimore, MD Mohamad A. Eloubeidi, MD, MHS, FACP, FACG Associate Professor of Medicine and Pathology Director, Endoscopic Ultrasound Program Co-Director, Pancreatico-biliary Center University of Alabama at Birmingham Birmingham, AL Ali Fazel, MD Assistant Professor of Medicine Co-Director, Center for Endoscopic Ultrasound Division of Gastroenterology, Hepatology and Nutrition Department of Medicine University of Florida Gainesville, FL

David G. Forcione, MD Assistant Physician Gastrointestinal Unit Massachusetts General Hospital Instructor of Medicine Harvard Medical School Boston, MA Eric Goldberg, MD Assistant Professor of Medicine University of Maryland Medical School Baltimore, MD John Horwhat, MD Duke University Durham, NC Wendy C. Hsu, MD Hospital of the University of Pennsylvania Philadelphia, PA Paul Jowell, MD Associate Professor of Medicine Division of Gastroenterology Duke University Medical Center Durham, NC Ann Marie Joyce, MD Instructor of Medicine Hospital of the University of Pennsylvania Philadelphia, PA Binita M. Kamath, MBBChir Division of GI & Nutrition The Children's Hospital of Philadelphia Philadelphia, PA Giorgos C. Karakousis, MD Resident in General Surgery Department of Surgery Hospital of the University of Pennsylvania Philadelphia, PA

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Contributing Authors

William B. Long, MD Associate Professor of Medicine Hospital of the University of Pennsylvania Philadelphia, PA Petar Mamula, MD Division of GI & Nutrition The Children's Hospital of Philadelphia Philadelphia, PA Jon B. Morris, MD Associate Professor of Surgery Program Director for General Surgery Division of GI Surgery Department of Surgery Hospital of the University of Pennsylvania Philadelphia, PA

Richard Shlansky-Goldberg, MD Department of Radiology Division of Interventional Radiology Hospital of the University of Pennsylvania Philadelphia, PA Evan S. Siegelman, MD Associate Professor of Radiology Department of Diagnostic Radiology Hospital of the University of Pennsylvania Philadelphia, PA William B. Silverman, MD, FACG Professor of Medicine Division of GI/Hepatology Department of Internal Medicine University of Iowa Hospitals & Clinics Iowa City, IA

Aalpen Patel, MD Department of Radiology Division of Interventional Radiology Hospital of the University of Pennsylvania Philadelphia, PA

Tyler Stevens, MD Department of Gastroenterology and Hepatology The Cleveland Clinic Foundation Cleveland, OH

Patrick R. Pfau, MD Assistant Professor of Medicine Director of Gastrointestinal Endoscopy University of Wisconsin Medical School Madison, WI

Francis Spitz, MD Assistant Professor of Surgery Department of Surgery Hospital of the University of Pennsylvania Philadelphia, PA

Rachel Rapaport Kelz, MD, MSCE Assistant Professor of Clinical Surgery Hospital of the University of Pennsylvania Philadelphia, PA

Raman R. Sreedharan, MD Division of GI & Nutrition AI DuPont Hospital for Children Wilmington, DE

Janak N. Shah, MD Director of Therapeutic Endoscopy San Francisco Veterans Medical Center Assistant Clinical Professor of Medicine University of California San Francisco, CA

Shyam Varadarajulu, MD Assistant Professor of Medicine Division of Gastroenterology-Hepatology University of Alabama at Birmingham School of Medicine Birmingham, AL

PREFACE This book was developed as part of the popular Clinician’s Guide series and focuses on the understanding, diagnosis, and management of disorders of the pancreas and biliary systems. Chapters are clear and concise and written in a uniform manner.

The multidisciplinary effort provides a broad and complete treatment of the topic.

Images, artwork, graphics, and tables provide a visually appealing complement to the robust text. We think clinicians will find this to be a ready and reliable resource when encountering patients with pancreaticobiliary disorders.

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Development and Function of the Pancreas, Bile Duct, and Gallbladder Binita M. Kamath, MBBChir; Raman R. Sreedharan, MD; Petar Mamula, MD

Introduction DEVELOPMENT AND FUNCTION OF THE PANCREAS The pancreas makes its appearance in the fetal embryo as early as the 4th week of gestation. The development of pancreas starts as a dorsal and a ventral outpouching from the endodermal lining of the primitive duodenum (Figure 1-1). The dorsal anlage appears earlier than the ventral anlage and eventually forms the neck, body, tail, and superior part of the head of the pancreas. The ventral anlage appears more caudally and is closely related to the bile duct and hepatic diverticulum and develops into the inferior part of the head and uncinate process of the pancreas. The two parts of the pancreas are brought into apposition by the partial rotation of the duodenum by 7 weeks of gestation, and they eventually fuse together. Each part of the primitive pancreas has an axial duct—the dorsal duct (duct of Santorini) arising directly from the duodenal wall and the ventral duct (duct of Wirsung) arising from the common bile duct. At the time of the fusion of the dorsal and ventral parts of the pancreas, the ducts fuse at the junction of the head and body of the pancreas to form the main pancreatic duct. In the majority of individuals, the ventral duct (duct of Wirsung) becomes the main excretory duct and opens into the major papilla along with the common bile duct. The proximal part of the dorsal duct (duct of Santorini) becomes the accessory duct and is patent in 70% of individuals. A wide variety of anatomic variations exist in relation to the fusion and openings of the dorsal and ventral ducts.

Both exocrine and endocrine cells originate from a common pluripotent progenitor under the influence of multiple transcription factors1. Distinct pathways like Hedgehog, Notch, and TGF-ß signaling promote or restrict cell differentiation and morphogenesis. Disruptions in these pathways may lead to development of various congenital anomalies (Table 1-1).

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Chapter 1

Figure 1-1. Embryology of the pancreas, liver, and biliary tree. (Reprinted from Moore K, et al. The Developing Human, 1982, with permission from Elsevier.)

Table 1-1

CONGENITAL ANOMALIES OF THE PANCREAS Pancreas divisum Pancreas annulare Heterotopic pancreas Aplasia Hypoplasia Dysplasia Ductal anomalies

The pancreas has an exocrine and an endocrine function. The exocrine function consists of production of various digestive enzymes such as lipase, amylase, proteases, and nuclease by acinar cells. The endocrine function unit are islets of Langerhans composed of four different types of cells: a type secreting glucagon, d type secreting somatostatin, PP cells secreting pancreatic polypeptide, and ß secreting insulin.

DEVELOPMENT OF THE BILIARY TRACT AND THE GALLBLADDER The liver primordium appears as a thickening of the ventral midline endoderm (the hepatic plate) by day 22 of development (see Figure 1-1). The cells in the hepatic plate proliferate to form the hepatic diverticulum that projects into the septum transversum.

The proliferating endodermal cells of the hepatic diverticulum invade the septum

Development and Function of the Pancreas, Bile Duct

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Figure 1-2. Morphogenesis of the intrahepatic ducts in mouse. At embryonic (E) day

15.5 the biliary precursor cells form a single-layered ring called ductal plate, which over the next two days becomes bilayered with focal dilations between the layers. These dilations give rise to the bile ducts, while the rest of the ductal plate regresses. (Adapted from Lemaigre F. Development of the biliary tract. Mechanisms of development. 2003;120:8187, with permission from Elsevier.)

transversum, forming cords of hepatoblasts. These hepatoblasts give rise to the intraand extrahepatic biliary system as well as the parenchymal elements of the liver.

The intrahepatic bile ducts develop primarily by a process of differentiation from the hepatocytes at the margins of the portal tracts. This differentiation results in the formation of the so-called ductal plate, a single layer or sleeve of cells surrounding a portal vein 2 (Figure 1-2). The ductal plate becomes a double layer of cells around 7 weeks of gestation. Through a process termed as remodeling, tubular structures form between the two cell layers of the ductal plate. These developing bile ductules express cytokeratins consistent with differentiated biliary epithelium. After completion of remodeling, the nontubular elements of the ductal plate involute, leaving only the centrally located, highly differentiated interlobular duct. Maturation of the intrahepatic biliary tree progresses from the hilum of the liver outwards to the periphery beginning at approximately 11 weeks gestational age and continues for several months after birth. The physiologic and biochemical factors governing the differentiation and remodeling of the ductal plate are essentially unknown at present, though the role of ductal-vascular interactions is increasingly being recognized.

The extrahepatic bile ducts and gallbladder develop from the caudal portion or pars cystica of the hepatic diverticulum before the 4th week of gestation. The pars cystica originates from the anterior side of the duodenum but assumes the definitive position of the common bile duct following rotation of the duodenum. The cystic portion of the hepatic diverticulum is initially hollow but the lumen is obliterated by proliferation of epithelial cells. The early gallbladder and extrahepatic biliary tree therefore consist of solid cords of epithelial cells in the 5th week of gestation. Subsequent vacuolization results in the formation of a lumen in the common bile duct by week 6 and this is fol-

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Chapter 1

lowed by canalization of the hepatic ducts. Finally, a definitive lumen develops in the cystic duct and the gallbladder by recanalization during the 7th week. The epithelium of the extrahepatic biliary system is continuous with the duodenum at one end and the primitive hepatic cords at the other.

The gallbladder is patent by the 3rd month of gestation and its wall contains muscle fibers. Bile secretion starts at the beginning of the 4th month of gestation and thereafter the biliary system constantly contains bile, which is secreted into the gut lumen.

The interlobular ducts formed from the differentiation and remodeling of the ductal plate are joined by intrahepatic extensions of the extrahepatic ducts, to complete the bile duct system.

Congenital Abnormalities of the Pancreas PANCREAS DIVISUM Pancreas divisum is the most common congenital anomaly of the pancreas. The incidence has been reported to be between 5% and 11% of the population3. Pancreas divisum arises as a result of the incomplete fusion of the dorsal and ventral ductal structures. This leads to persistence of two drainage systems. The ventral duct (duct of Wirsung) drains only the head of the pancreas through the major papilla. The dorsal duct (duct of Santorini) drains the body and tail of the pancreas through a smaller minor papilla, which is positioned proximal to the major papilla. The minor papilla through which the major portion of the pancreas drains could be too small for proper drainage and can lead to a functional stenosis.

Clinical Manifestations and Evaluation Pancreas divisum may cause recurrent abdominal pain. Additionally, the stenosis of the minor papilla has been implicated as a cause for recurrent pancreatitis.

Computed tomography (CT) scan of the abdomen may suggest the diagnosis, but the confirmation of the diagnosis is made by endoscopic retrograde cholangiopancreatography (ERCP) (Figure 1-3). Recently the noninvasive magnetic resonance cholangiopancreatography (MRCP) is being increasingly used.

Management Endoscopic therapies include papillotomy of the minor papilla with or without sphincterotomy of the major ampulla, ductal balloon dilatation, and pancreatic dorsal duct stent placement. Surgical therapy includes minor papilla sphincterotomy and sphincteroplasty.

ANNULAR PANCREAS This is the second most common anomaly of the pancreas, and occurs when a band of pancreatic tissue encircles the second part of the duodenum. There are several theories that have been put forward to explain the anomalous development:

1. Fixation of the tip of the ventral anlage resulting in failure of rotation.

2. Hypertrophy of the dorsal and ventral anlage resulting in a constriction around the duodenum.

Development and Function of the Pancreas, Bile Duct

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Figure 1-3. Pancreas divisum.

Contrast injection following cannulation of the ampulla of Vater demonstrates a small pancreatic duct of Wirsung. (Reprinted from M. Al Samman. Pancreas Divisum. eMedicine.com, Inc., 2004. Used with permission.)

3. Baldwin’s theory, which describes the persistence of the left ventral bud that normally atrophies during development.

Clinical Manifestations and Evaluation Symptoms depend on the severity of the constriction and most patients are asymptomatic. In severe cases, polyhydramnios is noted during pregnancy followed by feeding difficulty, vomiting, and abdominal distension during the neonatal period. In less severe cases, the manifestations are less dramatic and present at an older age or even adulthood with nausea, post-prandial fullness, vomiting, weight loss, and even gastrointestinal bleeding. In mild cases, there are no symptoms and the diagnosis is made as an incidental finding. In severe cases of constriction presenting in the neonatal period, the abdominal x-ray shows the classic “double bubble sign” (Figure 1-4) suggesting duodenal obstruction. In older children and adults, the upper intestinal contrast study findings of annular filling defect in the duodenum, prestenotic dilatation, and reverse peristalsis in the proximal segment are suggestive of annular pancreas. CT scan of the abdomen, MRCP, and ERCP are other useful investigative modalities. The diagnosis is confirmed at laparotomy.

Management Management is surgical. Surgical division of the pancreatic ring is associated with complications and hence avoided. Bypass surgery is the surgery of choice, whereas duodenostomy is done for isolated stenosis in children. Other extensive bypass surgeries may be performed depending on the anatomy.

HETEROTOPIC PANCREAS This anomaly, also called pancreatic rest, ectopic pancreas, accessory pancreas, or aberrant pancreas, is defined as pancreatic tissue lacking anatomic and vascular

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Chapter 1

Figure 1-4. Pancreas

annulare. Abdominal x-ray showing classic “double bubble” sign indicating duodenal obstruction seen in duodenal atresia and annular pancreas. (Used with permission from eMedicine.com, Inc., 2004.)

continuity with the main body of the pancreas. The incidence is up to 15% in autopsy specimens. Approximately 70% of heterotopic pancreas is located in the upper gastrointestinal tract. Other sites include gallbladder, liver, omentum, colon, appendix, Meckel’s diverticulum, intestinal duplication cysts, and extra intestinal sites such as bronchopulmonary sequestration and umbilicus. Histologically, both ductal and acinar tissues are recognized in the tissue.

Clinical Manifestations and Evaluation Symptoms if present include epigastric pain, gastrointestinal bleeding, abdominal distension, nausea, vomiting, and dyspepsia. Complications include mucosal ulcers with gastrointestinal bleeding, intussusceptions, intestinal obstruction, cholecystitis, jejunal atresia, and carcinoma arising from the aberrant tissue. This anomaly is usually found as incidental finding during endoscopy and it appears as discrete submucosal yellow nodules of sizes varying from 2 mm to 4 cm with a central umbilication (Figure 1-5). Biopsy of the nodule can confirm the diagnosis histologically.

Management Incidentally diagnosed heterotopic pancreases ideally do not require any intervention. Endoscopic ultrasound is an effective tool in accurate characterization. If the diagnosis is in doubt, surgical excision is considered, as it is both diagnostic and curative. In the event of complications, surgical excision is the procedure of choice.

PANCREATIC AGENESIS, HYPOPLASIA, AND DYSPLASIA Complete agenesis of the pancreas is incompatible with life and is rare. Partial agenesis is usually due to the abnormal development of the dorsal anlage, and the size and shape of the pancreas vary. In hypoplasia, the size and shape of the gland is

Development and Function of the Pancreas, Bile Duct

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Figure 1-5. Heterotopic

pancreas.

Endoscopic picture of heterotopic pancreas tissue in the antrum of the stomach.

normal but there is fatty tissue replacing the normal epithelial cells and reduced ductal differentiation. In dysplasia, there is abundant fibromuscular tissue with disorganized ductal and parenchymal tissues.

Clinical Manifestations and Evaluation Symptoms are variable and depend on the degree of involvement of the exocrine and endocrine functions. Manifestations include failure to thrive, malabsorption, and insulin-dependent diabetes. Studies including ERCP, MRCP, angiography, and abdominal and endoscopic ultrasound may be helpful. Also, cholycystokinin-secretin stimulation tests may be performed to assess the degree of pancreatic exocrine function. Definitive diagnosis is made during laparotomy or at autopsy.

Management The therapy is mainly supportive with insulin and pancreatic enzyme replacement.

Congenital Abnormalities of the Biliary Tract CONGENITAL ABNORMALITIES OF THE INTRAHEPATIC BILIARY DUCTS Intrahepatic bile duct anomalies encompass a wide range of disorders (Table 1-2).

A full discussion of intrahepatic biliary pathology is beyond the scope of this chapter and will be discussed elsewhere. Clinically important conditions have been included briefly.

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Chapter 1

Table 1-2

CONGENITAL ANOMALIES OF THE BILIARY TRACT Intrahepatic Bile Duct Anomalies Cystic disorders Solitary cysts Polycistic conditions (ARPKD/CHF, ADPKD, Caroli disease) Bile duct paucity Syndromic-Alagille syndrome Nonsyndromic

Extrahepatic Bile Duct Anomalies Biliary atresia* Agenesis Choledochal cyst Bile duct stenosis Accessory ducts Positional anomalies Duplication Spontaneous perforation Bronchobiliary fistula ADPKD = autosomal dominant polycystic kidney disease, ARPKD/CHF = autosomal recessive polycystic kidney disease/congenital hepatic fibrosis *Biliary atresia is not a true congenital anomaly; see text for further details.

Cystic Disorders Cystic conditions affecting the intrahepatic tree may be solitary or polycystic.

The distinction between communicating and noncommunicating cysts is clinically significant, as duct cysts communicating with the biliary tree have a greater likelihood of causing clinical disease. Communicating duct cysts can be associated with cholangitis, stone formation, and (relatively uncommonly) neoplasia. Noncommunicating duct cysts are usually asymptomatic, and may present as an abdominal mass or biliary obstruction.

Solitary Cysts

Definition Solitary cysts are noncommunicating developmental cysts, which are lined by simple cuboidal or biliary-type epithelium and are not associated with cysts in other organs. The surrounding hepatic parenchyma displays secondary atrophy, portal fibrosis, and bile duct proliferation.

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