- Chandrashekhar Thukral, MD, PhD
Chandrashekhar Thukral, MD, PhD
- Clinical Assistant Professor of Medicine
- University of Illinois, College of Medicine at Rockford
- Steven D Freedman, MD, PhD
Steven D Freedman, MD, PhD
- Professor of Medicine
- Harvard Medical School
Annular pancreas is a rare congenital abnormality characterized by a ring of pancreatic tissue surrounding the descending portion of the duodenum. It is thought to originate from incomplete rotation of the ventral pancreatic bud. This topic will review the pathogenesis, clinical manifestations, diagnosis, and management of annular pancreas. Other causes of duodenal obstruction and congenital abnormalities of the pancreas, including pancreas divisum, are discussed in detail, separately. (See "Intestinal malrotation in children" and "Intestinal atresia" and "Pancreas divisum: Clinical manifestations and diagnosis".)
The exact prevalence of annular pancreas is unclear as many individuals with annular pancreas are asymptomatic. In autopsy series in which duodenal dissection has been performed, the prevalence of annular pancreas ranges from 5 to 15 per 100,000 adults [1-3]. Annular pancreas has been associated with maternal polyhydramnios and congenital abnormalities such as Down syndrome, esophageal and duodenal atresia, imperforate anus, and Meckel's diverticulum [4-6]. (See "Down syndrome: Clinical features and diagnosis" and "Intestinal atresia" and "Meckel's diverticulum".)
EMBRYOLOGY AND PATHOGENESIS
The pancreas develops from one dorsal and two ventral buds that first appear as evaginations of the primitive foregut at around the fifth week of gestation. Due to selective expansion of the duodenum, by approximately the seventh week, the ventral bud rotates with the gut, passing behind the duodenum from the right to left and eventually fusing with the dorsal bud. The ventral bud forms the inferior part of the head of the pancreas and the uncinate process, whereas the dorsal bud becomes the tail and the body. Fusion of the ductular network of the two buds gives rise to the main pancreatic duct. The accessory pancreatic duct, which often persists, is derived from the dorsal pancreatic duct proximal to the site of fusion (figure 1) [7-9].
Annular pancreas results from failure of the ventral bud to rotate with the duodenum, causing envelopment of duodenum. Three major theories have been proposed to explain the development of annular pancreas:
●Adherence of the ventral bud to the duodenal wall prior to rotation, resulting in its persistence and encirclement of the duodenum (Lecco's theory) .To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information on subscription options, click below on the option that best describes you:
- Ravitch MM. The pancreas in infants and children. Surg Clin North Am 1975; 55:377.
- THEODORIDES T. [ANNULAR PANCREAS]. J Chir (Paris) 1964; 87:445.
- RAVITCH MM, WOODS AC Jr. Annular pancreas. Ann Surg 1950; 132:1116.
- HAYS DM, GREANEY EM Jr, HILL JT. Annular pancreas as a cause of acute neonatal duodenal obstruction. Ann Surg 1961; 153:103.
- Sencan A, Mir E, Günsar C, Akcora B. Symptomatic annular pancreas in newborns. Med Sci Monit 2002; 8:CR434.
- Zyromski NJ, Sandoval JA, Pitt HA, et al. Annular pancreas: dramatic differences between children and adults. J Am Coll Surg 2008; 206:1019.
- Moodley S, Hegarty M, Thomson SR. Annular pancreas. S Afr Med J 2004; 94:28.
- Lee PC, Lebnethal E. Prenatal and postnatal development of the human exocrine pancreas. In: Pancreas: Pathology, Pathobiology and Disease, 2nd ed, Go VL, Dimagno EP, Gardner JD, et al (Eds), Raven Press, New York 1993. p.57.
- Kozu T, Suda K, Toki F. Pancreatic development and anatomical variation. Gastrointest Endosc Clin N Am 1995; 5:1.
- Laughlin EH, Keown ME, Jackson JE. Heterotopic pancreas obstructing the ampulla of Vater. Arch Surg 1983; 118:979.
- Baldwin W. A specimen of annular pancreas. Anat Rec 1910; 4:299.
- Hill ID, Lebenthal E. Congenital abnormalities of the exocrine pancreas. In: Pancreas: Pathology, Pathobiology and Disease, 2nd ed, Go VL, Dimagno EP, Gardner JD, et al (Eds), Raven Press, New York 1993. p.1029.
- Lin SZ. Annular pancreas. Etiology, classification and diagnostic imaging. Chin Med J (Engl) 1989; 102:368.
- Cunha JE, de Lima MS, Jukemura J, et al. Unusual clinical presentation of annular pancreas in the adult. Pancreatology 2005; 5:81.
- Gilinsky NH, Lewis JW, Flueck JA, Fried AM. Annular pancreas associated with diffuse chronic pancreatitis. Am J Gastroenterol 1987; 82:681.
- Baggott BB, Long WB. Annular pancreas as a cause of extrahepatic biliary obstruction. Am J Gastroenterol 1991; 86:224.
- Green JD, Fieber SS, Buniak B. Annular pancreas with dilated biliary and pancreatic ducts. Am J Gastroenterol 1993; 88:467.
- Shan YS, Sy ED, Lin PW. Annular pancreas with obstructive jaundice: beware of underlying neoplasm. Pancreas 2002; 25:314.
- Sandrasegaran K, Patel A, Fogel EL, et al. Annular pancreas in adults. AJR Am J Roentgenol 2009; 193:455.
- Yogi Y, Shibue T, Hashimoto S. Annular pancreas detected in adults, diagnosed by endoscopic retrograde cholangiopancreatography: report of four cases. Gastroenterol Jpn 1987; 22:92.
- Kiernan PD, ReMine SG, Kiernan PC, ReMine WH. Annular pancreas: May Clinic experience from 1957 to 1976 with review of the literature. Arch Surg 1980; 115:46.
- Jimenez JC, Emil S, Podnos Y, Nguyen N. Annular pancreas in children: a recent decade's experience. J Pediatr Surg 2004; 39:1654.
- Urayama S, Kozarek R, Ball T, et al. Presentation and treatment of annular pancreas in an adult population. Am J Gastroenterol 1995; 90:995.
- Chen YC, Yeh CN, Tseng JH. Symptomatic adult annular pancreas. J Clin Gastroenterol 2003; 36:446.
- England RE, Newcomer MK, Leung JW, Cotton PB. Case report: annular pancreas divisum--a report of two cases and review of the literature. Br J Radiol 1995; 68:324.
- Maker V, Gerzenshtein J, Lerner T. Annular pancreas in the adult: two case reports and review of more than a century of literature. Am Surg 2003; 69:404.
- Gress F, Yiengpruksawan A, Sherman S, et al. Diagnosis of annular pancreas by endoscopic ultrasound. Gastrointest Endosc 1996; 44:485.
- Papachristou GI, Topazian MD, Gleeson FC, Levy MJ. EUS features of annular pancreas (with video). Gastrointest Endosc 2007; 65:340.
- Poki HO, Holland AJ, Pitkin J. Double bubble, double trouble. Pediatr Surg Int 2005; 21:428.
- Imamoglu M, Cay A, Sarihan H, Sen Y. Rare clinical presentation mode of intestinal malrotation after neonatal period: Malabsorption-like symptoms due to chronic midgut volvulus. Pediatr Int 2004; 46:167.
- Yoshizato T, Satoh S, Taguchi T, et al. Intermittent 'double bubble' sign in a case of congenital pyloric atresia. Fetal Diagn Ther 2002; 17:334.
- Malone FD, Crombleholme TM, Nores JA, et al. Pitfalls of the 'double bubble' sign: a case of congenital duodenal duplication. Fetal Diagn Ther 1997; 12:298.
- Itoh Y, Hada T, Terano A, et al. Pancreatitis in the annulus of annular pancreas demonstrated by the combined use of computed tomography and endoscopic retrograde cholangiopancreatography. Am J Gastroenterol 1989; 84:961.
- Choi JY, Kim MJ, Kim JH, et al. Annular pancreas: emphasis on magnetic resonance cholangiopancreatography findings. J Comput Assist Tomogr 2004; 28:528.
- Chevallier P, Souci J, Buckley MJ, et al. Annular pancreas: MR imaging including MR cholangiopancreatography (MRCP). Pancreas 1999; 18:216.
- Hidaka T, Hirohashi S, Uchida H, et al. Annular pancreas diagnosed by single-shot MR cholangiopancreatography. Magn Reson Imaging 1998; 16:441.
- Kimble RM, Harding J, Kolbe A. Additional congenital anomalies in babies with gut atresia or stenosis: when to investigate, and which investigation. Pediatr Surg Int 1997; 12:565.
- De Ugarte DA, Dutson EP, Hiyama DT. Annular pancreas in the adult: management with laparoscopic gastrojejunostomy. Am Surg 2006; 72:71.
- Thomford NR, Knight PR, Pace WG, Madura JA. Annular pancreas in the adult: selection of operation. Ann Surg 1972; 176:159.
- Benger JR, Thompson MH. Annular pancreas and obstructive jaundice. Am J Gastroenterol 1997; 92:713.
- Mustafawi AR, Hassan ME. Congenital duodenal obstruction in children: a decade's experience. Eur J Pediatr Surg 2008; 18:93.
- EMBRYOLOGY AND PATHOGENESIS
- CLINICAL MANIFESTATIONS
- DIFFERENTIAL DIAGNOSIS
- Abdominal imaging
- - Abdominal radiographs
- - Upper gastrointestinal series
- - Abdominal CT scan
- - Cholangiopancreatogram
- ADDITIONAL EVALUATION
- SUMMARY AND RECOMMENDATIONS