Duodenal Obstruction Due to Annular Pancreas

An annular pancreas is simply a band of secreting pancreatic tissue arising from the head of the pancreas and passing around the second portion of the duodenum, although involvement of the third portion has also been reported. If the ring is incomplete, it will take the form of two arms reaching out from the pancreatic head, partially encircling the duodenum and leaving a gap on the ventral surface which is filled with loose fibrous tissue. The degree of obstruction varies from case to case. In some, it is complete, with underlying duodenal atresia, whereas in others there is no obstruction, and the condition is discovered incidentally at autopsy. In 1933, McNaught (1) reviewed the literature and collected 40 cases of annular pancreas. In 1942, Lehman (2), again reviewing the literature, found 48 cases. Of these, only 10 had been treated surgically. In 1944 Gross and Chisholm (3) reported the first case of annular pancreas in an infant operated upon in this country. Three more cases treated by operation were reported at the end of 1950 by Ravitch and Woods (4), 2 of which were in infants. In June 1951, Payne (5) collected a total of 58 cases, including 1 of his own, of which only 18 had been treated surgically. By February of 1952, Silvis (6) was able to find 26 surgical cases in the literature, to which he added another. Of this group 5 were seen in the neonatal period. Four more surgical cases then appeared in the literature, but these were all in adults (7, 8). Shapiro, Dzurik and Gerrish (9) later in 1952 reported 4 more cases in infants, bringing the total number to 9. In January 1953, Castleton, Morris and Kukral (10) added another adult surgical case. In June 1953, Gillespie and Moore (11) reported 1 case in an infant and mentioned 2 others to be reported. This made a total of 12 operations in the neonatal period. Gross, in his textbook, The Surgery of Infancy and Childhood (12), appearing in the summer of 1953, listed a total of 15 cases from the Boston Children's Hospital, of which 10 were treated surgically. He had already reported the first of this latter group, so that 9 cases in infancy were added. As of July 1953, there have been reported about 85 cases of annular pancreas, of which number 48 have been operated upon. Of this operated group, 21 cases have been in infants. About half of the cases reported were incidental findings at autopsy. While the reporting of this anomaly has been increasing in frequency in the surgical literature, there is a conspicuous absence of such reports in the radiological literature. The writers have succeeded in finding but three references in American radiological journals (13, 14, 15). Even in Poppel's excellent book (16), Roentgen Manifestations of Pancreatic Disease, only two and one-half pages are devoted to this anomaly.