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Annular pancreas in the adult
Annular Pancreas in the Adult H. CLAY ALEXANDER,
There have been little more than one hundred patients with annular pancreas reported since the condition was first described by Ecker in 1862. Although many of these patients are first seen during infancy and childhood, this is the only congenital anomaly of the gastrointestinal tract in which the symptoms usually start later in life. The purpose of this paper is to discuss the various aspects of this anomaly, with emphasis on the late development of symptoms. In addition, four cases of proved annular pancreas in adults will be reported and similar roentgenographic signs in three of these patients will be described. Embryology
and Histology
There are two main theories of the embryologic development of the annulus as set forth by Tendler and Ciuti [I] and Castleton, Morris, and Kukral [2]. The first states that the condition is due to the failure of the ventral anlage of the pancreas to rotate with the duodenum. The second involves hypertrophy of both the ventral and dorsal anlages. The annulus, however formed, contains entirely normal acinar and islet tissue. It is indistinguishable from normal pancreas and subject to the same disease states. Associated
Anomalies
Stofer [3] and McNaught [4] state that annular pancreas is associated with additional anomalies in 20 to 25 per cent of patients. Most of these involve malformations of the abdominal viscera. True duodenal stenosis, according to Whelan and Hamilton [5], is present in 12 to 19 per cent of patients. Clinical
Symptoms
and
Associated
Complications
The clinical symptoms in the patient with an uncomplicated case are those of chronic partial duodenal obstruction. There is postprandial nausea and epigastric fullness, which are only partially relieved by vomiting. No relief is obtained from antacids or from lying down. These symptoms usually occur over a period of months or years and may be accompanied by weight loss. There are three complications of the anomaly which may first bring the condition to the attention From the Department of Physicians and Surgeons. terian Hospital, New York,
702
Surgery, Columbia and the Surgical New York.
University Service of
College of the Presby-
MD, New York, New York
of a physician. Peptic ulceration, as reported by Whelan and Hamilton [.5], is found in 32 per cent of cases and is presumed secondary to stasis. The duodenal, or more commonly, gastric ulceration can present in any of the usual ways. Acute pancreatitis is the initial problem in 16 per cent, and Silvis [6] states that 60 per cent of the annuli partially resected at operation show changes of chronic pancreatitis. Bickford and Williamson [7] believe the gland to be prone to such inflammatory changes because of the constant peristaltic motion of the obstructed duodenum. Partial obstruction of the pancreatic system may also account for this. Common duct obstruction is a rare complication because, according to Mac Phee [8], the duodenal constriction is usually proximal to the ampulla of Vater. When this does occur, the biliary obstruction may be secondary to pancreatitis. Four adults with annular pancreas are reported in this series. Case
Reports
CASE I. The patient, a sixty-eight year old woman, presented with vague abdominal pain of six months’ duration. She was appropriately treated by Billroth II gastrectomy because of an associated gastric ulcer. The patient has been asymptomatic for sixteen years. CASE II. The patient, a thirty-four year old woman, had had a duodenal ulcer which had been treated ten years previously by gastroenterostomy. Because of epigastric pain, nausea, and vomiting of two months’ duration, operation was performed with release of a duodenal band and partial excision of the annular ring. The patient went without symptoms for fourteen years until epigastric burning developed a year ago. No new pathologic disorder could be seen on roentgenographic studies, however, and the patient was managed successfully by conservative measures. CASE III. The patient, a seventy-four year old man, entered the hospital with abdominal pain of one months’ duration and profound anemia. Although stools were guaiac-positive, no explanation for this could be found either by roentgenographic studies or at operation. Cholecystectomy was performed for a gallstone found incidently and the duodenal obstruction was bypassed by gastroenterostomy. There was transient low grade bilirubinemia with mild amylase elevation during the postoperative course which was thought to be due to pancre-
The
American
Journal
of Surgery
Annular
atitis. The patient doing well.
is now one year post-operative
and is
CASE IV. The patient, a nineteen year old woman, entered the hospital with an eight month history of epigastric pain and nausea. It is of interest that the patient had lost a considerable amount of weight (25 pounds) from dieting immediately prior to the onset of symptoms. Whether this rapid weight reduction had finally precipitated the duodenal obstruction is a matter for speculation. Retrocolic duodenojejunostomy was performed, and the patient has now been well for six months after a troublesome early postoperative course during which time the stoma drained poorly. Operative Procedures The operative procedures used for the correction of this condition fall primarily into three categories. The first is resection or division of the annulus. This method is considered inadvisable because of the risk both of pancreatitis and of fistula formation. In addition, an associated duodenal stenosis would not be corrected by this procedure. Hyden [9] and Anderson and Wapshaw [lo] state that when these two anomalies coexist, the annular tissue may actually intermingle with the duodenal musculature. Gastric resection of the Billroth II type is indicated when there is an associated peptic ulceration. In the eleven cases reported by Whelan and Hamilton 151 of Billroth II gastrectomy with the annulus left intact, there was no instance of duodenal stump leakage. Bypass operations are the procedures of choice for the simple annular pancreas. Either duodenoduodenostomy or retrocolic duodenojejunostomy are equally effective. The choice of operation depends on the individual anatomic situation. Gastroenterostomy alone is inadvisable because it often does not completely relieve the symptoms of duodenal obstruction and is subject to marginal ulceration.
Pancreas in Adults
obstruction could lead to angulation at the annulus. Such a ptosis could gradually increase with advancing age. This altered anatomic arrangement of the duodenal bulb produces a quite characteristic roentgenographic picture. Payne [I I], in 1951, reported a patient with annular pancreas in whom the description of the finding on upper gastrointestinal studies was as follows : “The first and second portions of the duodenum show marked dilatation and stasis. The angle formed between the second and third portions of the duodenum is the highest portion of the duodenum, so that the stomach contents poured out into the first and second portions and then had to travel uphill.” A diagnosis was made, on this basis, of “anomalous duodenum.” Likewise, in the case of the thirty-four year old woman in the present series, the description of the roentgenogram (Figure I) reads: “There was an anomaly of the duodenal sweep whereby it swung to the right and then on a superior direction and then to the left.” Again, in the nineteen year old woman in case IV a nearly identical picture is seen and described (Figures 2 and 3): “The apex of the bulb pointed superiorly and medially so that the duodenum described a clockwise circle.” This situation was interpreted as an “anatomic variation in the duodenal circle.” At operation upon this patient, the duodenal bulb was found to have become dilated, flabby, and mobile, thus permitting it to ptose anteriorly across the fixed annulus. It would thus be held in a sharp obstructing fold when the bulb was partially filled with fluid. Although the duodenum is not described as “anom-
2
Late Onset of Symptoms The explanation for the late appearance of symptoms of this congenital anomaly has long been a subject of interest and speculation, If the annulus is very tight from the outset, it will cause obstruction in infancy or early childhood, If mild asymptomatic stasis is present over a long period, it can lead to ulceration in the stomach or duodenum. Likewise, pancreatitis may occur in the annulus and can thus further narrow a partially obstructed but previously asymptomatic duodenum. But why should signs of chronic partial duodenal obstruction without associated ulceration or pancreatitis develop in an elderly person or even in a teenager? In 1955 Beck suggested that ptosis of the first portion of the duodenum secondary to the duodenal
Vol.
119. June
1970
Figure 1. Upper gastrointestinal series year old woman showing the clockwise duodenal sweep. Duodenum describing Figure 2. nineteen year old woman.
in a thirty-four rotation
a clockwise
circle
of
the in a
703
Alexander
Figure 3. Ptosis and distention of the first portion of the duodenum is evident in a nineteen year old woman. Figure 4. Distention of the duodenal bulb and reversal of the usual duodenal flow pattern in a seventy-four year old man.
alous” in the seventy-four year old man in case III, the roentgenographic picture (Figure 4) again shows a reversal of the duodenal flow pattern from counterclockwise to clockwise. Actually, the duodenum is not congenitally anomalous in any of these patients except possibly for its unusual mobility. It is not known whether gradual dilatation over a period of time could by itself account for the abnormal mobility and unusual freedom from the duodenum’s peritoneal supports. This purely mechanical phenomenon could be sufficient to explain the late onset of symptoms in those patients with annular pancreas but without pancreatitis or ulceration. Summary
and Conclusions
Annular pancreas is the only congenital anomaly of the gastrointestinal tract in which symptoms usually manifest themselves in adult life. The condition is associated with additional anomalies in 25 per cent of patients. The clinical symptoms are those of chronic partial duodenal obstruction. Peptic ulceration, acute pancreatitis, and common duct obstruction are associated complications. Our experience suggests that the explanation for
704
the late onset of symptoms, in those patients without the aforementioned complications, may be the ptosis and angulation of the distended and mobile duodenum across the fixed annulus. The typical roentgenographic findings seen in the “ptotic” cases are stressed. References 1. Tendler 2. 3. 4. 5. 6. 7. 8. 9.
MJ, Ciuti A: Surgery of annular pancreas. Ann Surg 38: 298, 1955. _ Castleton KR. Morris RP. Kukral AJ: Annular oancreas. Amer Surg 19: 38, 19i3. Stofer BE: Annular pancreas. Amer J Med Sci 207: 430, 1944. McNaught JB: Annular pancreas. Amer J Med Sci 185: 249,1933. Whelan TJ Jr, Hamilton EB: Annular pancreas. Ann Surg 146: 252, 1957. Silvis RS: Annular pancreas. Ann Surg 135: 278, 1952. Bickford BJ, Williamson CF: Annular pancreas. Brit J Surg 39: 49, 1951. Mac Phee IW: Annular pancreas. Brit J Surg 40: 510, 1953. Hyden WH: The true nature of annular pancreas. Ann
Surg 157: 71, 1963. 10. Anderson JR, Wapshaw H: Annular pancreas. Brit J Surg 39: 43, 1951. 11. Payne RL Jr: Annular pancreas. Ann Surg 133: 754, 1951.
The American Journal of Surgery
There have been little more than one hundred patients with annular pancreas reported since the condition was first described by Ecker in 1862. Although many of these patients are first seen during infancy and childhood, this is the only congenital anomaly of the gastrointestinal tract in which the symptoms usually start later in life. The purpose of this paper is to discuss the various aspects of this anomaly, with emphasis on the late development of symptoms. In addition, four cases of proved annular pancreas in adults will be reported and similar roentgenographic signs in three of these patients will be described. Embryology
and Histology
There are two main theories of the embryologic development of the annulus as set forth by Tendler and Ciuti [I] and Castleton, Morris, and Kukral [2]. The first states that the condition is due to the failure of the ventral anlage of the pancreas to rotate with the duodenum. The second involves hypertrophy of both the ventral and dorsal anlages. The annulus, however formed, contains entirely normal acinar and islet tissue. It is indistinguishable from normal pancreas and subject to the same disease states. Associated
Anomalies
Stofer [3] and McNaught [4] state that annular pancreas is associated with additional anomalies in 20 to 25 per cent of patients. Most of these involve malformations of the abdominal viscera. True duodenal stenosis, according to Whelan and Hamilton [5], is present in 12 to 19 per cent of patients. Clinical
Symptoms
and
Associated
Complications
The clinical symptoms in the patient with an uncomplicated case are those of chronic partial duodenal obstruction. There is postprandial nausea and epigastric fullness, which are only partially relieved by vomiting. No relief is obtained from antacids or from lying down. These symptoms usually occur over a period of months or years and may be accompanied by weight loss. There are three complications of the anomaly which may first bring the condition to the attention From the Department of Physicians and Surgeons. terian Hospital, New York,
702
Surgery, Columbia and the Surgical New York.
University Service of
College of the Presby-
MD, New York, New York
of a physician. Peptic ulceration, as reported by Whelan and Hamilton [.5], is found in 32 per cent of cases and is presumed secondary to stasis. The duodenal, or more commonly, gastric ulceration can present in any of the usual ways. Acute pancreatitis is the initial problem in 16 per cent, and Silvis [6] states that 60 per cent of the annuli partially resected at operation show changes of chronic pancreatitis. Bickford and Williamson [7] believe the gland to be prone to such inflammatory changes because of the constant peristaltic motion of the obstructed duodenum. Partial obstruction of the pancreatic system may also account for this. Common duct obstruction is a rare complication because, according to Mac Phee [8], the duodenal constriction is usually proximal to the ampulla of Vater. When this does occur, the biliary obstruction may be secondary to pancreatitis. Four adults with annular pancreas are reported in this series. Case
Reports
CASE I. The patient, a sixty-eight year old woman, presented with vague abdominal pain of six months’ duration. She was appropriately treated by Billroth II gastrectomy because of an associated gastric ulcer. The patient has been asymptomatic for sixteen years. CASE II. The patient, a thirty-four year old woman, had had a duodenal ulcer which had been treated ten years previously by gastroenterostomy. Because of epigastric pain, nausea, and vomiting of two months’ duration, operation was performed with release of a duodenal band and partial excision of the annular ring. The patient went without symptoms for fourteen years until epigastric burning developed a year ago. No new pathologic disorder could be seen on roentgenographic studies, however, and the patient was managed successfully by conservative measures. CASE III. The patient, a seventy-four year old man, entered the hospital with abdominal pain of one months’ duration and profound anemia. Although stools were guaiac-positive, no explanation for this could be found either by roentgenographic studies or at operation. Cholecystectomy was performed for a gallstone found incidently and the duodenal obstruction was bypassed by gastroenterostomy. There was transient low grade bilirubinemia with mild amylase elevation during the postoperative course which was thought to be due to pancre-
The
American
Journal
of Surgery
Annular
atitis. The patient doing well.
is now one year post-operative
and is
CASE IV. The patient, a nineteen year old woman, entered the hospital with an eight month history of epigastric pain and nausea. It is of interest that the patient had lost a considerable amount of weight (25 pounds) from dieting immediately prior to the onset of symptoms. Whether this rapid weight reduction had finally precipitated the duodenal obstruction is a matter for speculation. Retrocolic duodenojejunostomy was performed, and the patient has now been well for six months after a troublesome early postoperative course during which time the stoma drained poorly. Operative Procedures The operative procedures used for the correction of this condition fall primarily into three categories. The first is resection or division of the annulus. This method is considered inadvisable because of the risk both of pancreatitis and of fistula formation. In addition, an associated duodenal stenosis would not be corrected by this procedure. Hyden [9] and Anderson and Wapshaw [lo] state that when these two anomalies coexist, the annular tissue may actually intermingle with the duodenal musculature. Gastric resection of the Billroth II type is indicated when there is an associated peptic ulceration. In the eleven cases reported by Whelan and Hamilton 151 of Billroth II gastrectomy with the annulus left intact, there was no instance of duodenal stump leakage. Bypass operations are the procedures of choice for the simple annular pancreas. Either duodenoduodenostomy or retrocolic duodenojejunostomy are equally effective. The choice of operation depends on the individual anatomic situation. Gastroenterostomy alone is inadvisable because it often does not completely relieve the symptoms of duodenal obstruction and is subject to marginal ulceration.
Pancreas in Adults
obstruction could lead to angulation at the annulus. Such a ptosis could gradually increase with advancing age. This altered anatomic arrangement of the duodenal bulb produces a quite characteristic roentgenographic picture. Payne [I I], in 1951, reported a patient with annular pancreas in whom the description of the finding on upper gastrointestinal studies was as follows : “The first and second portions of the duodenum show marked dilatation and stasis. The angle formed between the second and third portions of the duodenum is the highest portion of the duodenum, so that the stomach contents poured out into the first and second portions and then had to travel uphill.” A diagnosis was made, on this basis, of “anomalous duodenum.” Likewise, in the case of the thirty-four year old woman in the present series, the description of the roentgenogram (Figure I) reads: “There was an anomaly of the duodenal sweep whereby it swung to the right and then on a superior direction and then to the left.” Again, in the nineteen year old woman in case IV a nearly identical picture is seen and described (Figures 2 and 3): “The apex of the bulb pointed superiorly and medially so that the duodenum described a clockwise circle.” This situation was interpreted as an “anatomic variation in the duodenal circle.” At operation upon this patient, the duodenal bulb was found to have become dilated, flabby, and mobile, thus permitting it to ptose anteriorly across the fixed annulus. It would thus be held in a sharp obstructing fold when the bulb was partially filled with fluid. Although the duodenum is not described as “anom-
2
Late Onset of Symptoms The explanation for the late appearance of symptoms of this congenital anomaly has long been a subject of interest and speculation, If the annulus is very tight from the outset, it will cause obstruction in infancy or early childhood, If mild asymptomatic stasis is present over a long period, it can lead to ulceration in the stomach or duodenum. Likewise, pancreatitis may occur in the annulus and can thus further narrow a partially obstructed but previously asymptomatic duodenum. But why should signs of chronic partial duodenal obstruction without associated ulceration or pancreatitis develop in an elderly person or even in a teenager? In 1955 Beck suggested that ptosis of the first portion of the duodenum secondary to the duodenal
Vol.
119. June
1970
Figure 1. Upper gastrointestinal series year old woman showing the clockwise duodenal sweep. Duodenum describing Figure 2. nineteen year old woman.
in a thirty-four rotation
a clockwise
circle
of
the in a
703
Alexander
Figure 3. Ptosis and distention of the first portion of the duodenum is evident in a nineteen year old woman. Figure 4. Distention of the duodenal bulb and reversal of the usual duodenal flow pattern in a seventy-four year old man.
alous” in the seventy-four year old man in case III, the roentgenographic picture (Figure 4) again shows a reversal of the duodenal flow pattern from counterclockwise to clockwise. Actually, the duodenum is not congenitally anomalous in any of these patients except possibly for its unusual mobility. It is not known whether gradual dilatation over a period of time could by itself account for the abnormal mobility and unusual freedom from the duodenum’s peritoneal supports. This purely mechanical phenomenon could be sufficient to explain the late onset of symptoms in those patients with annular pancreas but without pancreatitis or ulceration. Summary
and Conclusions
Annular pancreas is the only congenital anomaly of the gastrointestinal tract in which symptoms usually manifest themselves in adult life. The condition is associated with additional anomalies in 25 per cent of patients. The clinical symptoms are those of chronic partial duodenal obstruction. Peptic ulceration, acute pancreatitis, and common duct obstruction are associated complications. Our experience suggests that the explanation for
704
the late onset of symptoms, in those patients without the aforementioned complications, may be the ptosis and angulation of the distended and mobile duodenum across the fixed annulus. The typical roentgenographic findings seen in the “ptotic” cases are stressed. References 1. Tendler 2. 3. 4. 5. 6. 7. 8. 9.
MJ, Ciuti A: Surgery of annular pancreas. Ann Surg 38: 298, 1955. _ Castleton KR. Morris RP. Kukral AJ: Annular oancreas. Amer Surg 19: 38, 19i3. Stofer BE: Annular pancreas. Amer J Med Sci 207: 430, 1944. McNaught JB: Annular pancreas. Amer J Med Sci 185: 249,1933. Whelan TJ Jr, Hamilton EB: Annular pancreas. Ann Surg 146: 252, 1957. Silvis RS: Annular pancreas. Ann Surg 135: 278, 1952. Bickford BJ, Williamson CF: Annular pancreas. Brit J Surg 39: 49, 1951. Mac Phee IW: Annular pancreas. Brit J Surg 40: 510, 1953. Hyden WH: The true nature of annular pancreas. Ann
Surg 157: 71, 1963. 10. Anderson JR, Wapshaw H: Annular pancreas. Brit J Surg 39: 43, 1951. 11. Payne RL Jr: Annular pancreas. Ann Surg 133: 754, 1951.
The American Journal of Surgery