*Corresponding author:Byshetty Rajendar, Senior Resident, Department of General surgery, JIPMER, Pondicherry, India
How to cite this article:Byshetty R, Shanmugam D, Kadambari D, Sravani T. Reversed Intestinal Rotation with Annular Pancreas Presented as Acute
Necrotizing Pancreatitis- A Case report. Adv Res Gastroentero Hepatol, 2020;15(2): 555909. DOI: 10.19080/ARGH.2020.15.555909.
Reversed intestinal rotation (RIR) is a rarest form of the intestinal rotational abnormalities . Annular pancreas is also a rare congenital anomaly which can be associated with intestinal malrotation . Annular pancreas presents rarely with duodenal obstruction, pancreatitis and peptic ulceration in adults . Only a few cases of pancreatitis related to an annular pancreas have previously been reported. This is the first case report of annular pancreas associated with intestinal malrotation, presenting as acute necrotizing pancreatitis in an adult.
A 45 years old female presented to the Emergency Room with complaints of upper abdominal pain associated with vomiting for 3 days. She had continuous, throbbing pain in the epigastric and left hypochondrial region. It was associated with bilious vomiting. She also had abdominal distention. She did not have fever or decreased urine output. She was non-alcoholic. She had no history of drug intake for any medical illness. On examination she was conscious, afebrile, dehydrated. She had tachypnea and tachycardia. Her abdomen was tense with diffuse tenderness and guarding. Bowel sounds were normal. She was resuscitated with IV fluids in emergency room.
Initial investigations revealed serum amylase 956 IU/L. Her liver enzymes, serum calcium, triglyceride levels were within normal limits. Abdominal ultrasound revealed minimal free fluid abdomen. Pancreas was obscured by bowel gas, gall bladder
and common bile duct were normal. CT abdomen demonstrated
diffusely enlarged pancreas with shaggy contour and non-
enhancing pancreas for more than 30% in the head and proximal body region (Figure 1). Modified CT Severity Index (CTSI) was 8, suggestive of Acute severe Pancreatitis. There was part of the head noted on the right of the second part of duodenum which was continuous with the rest of the pancreas suggestive of Annular Pancreas (Figure 2). The third part of the duodenum was seen anterior to the superior mesenteric artery and transverse colon found to be behind the SMA (Figure 3). The hepatic flexure, ascending colon and caecum were seen in the right iliac fossa due to non fixation, consistent with reverse rotation of the intestine (Figure 4). There were no signs suggestive of pancreatic infection.
The patient responded to conservative management with
intravenous fluids, analagesics and antiemetics. She was gradually
started on orals on day 3 and was discharged on day 7.
RIR is rarest of all rotational abnormalities of the intestine,
representing approximately 2-4% of reported cases of malrotation
. RIR is due to error in the second stage of midgut rotation. In
this anomaly, the gut rotates 90° in a clockwise direction around
the axis of the superior mesenteric artery instead of 270° in an
anticlockwise direction such that the transverse colon moves
to the right behind the superior mesenteric vessels and the
duodenum lies anterior to the colon . The rest of the bowel can
occupy a normal position but its visceral surface is reversed.
Congenital anomalies of the intestinal rotation are seen
commonly in infancy and childhood. They may present with
volvulus of the ileocecal segment due to its narrow mesenteric
attachment, large bowel obstruction at the retroarterial segment
of transverse colon and rarely small bowel obstruction at the
duodenojejunal junction by periduodenal bands . They are
uncommon in adults and majority of the cases are usually
asymptomatic [6,7]. But some patients may present with chronic
unexplained and atypical symptoms like vague abdominal pain
and weight loss, while very few may experience an acute episode
of duodenal or intestinal obstruction . Our patient was
asymptomatic until she presented with acute severe pancreatitis.
Annular pancreas, a pancreatic fusion anomaly, has an
incidence of approximately 0.005% . During development of
pancreas, ventral bud rotates and passes behind the duodenum
from right to left and fuses with the dorsal bud to form the inferior
part of the uncinate process and part of the head of pancreas,
whereas the dorsal bud gives rise to the tail and the body. Fusion
of the ducts of the two buds produces the main pancreatic duct.
Annular pancreas results from failure of the ventral bud to rotate
with the duodenum, resulting in envelopment of the duodenum
Annular pancreas presentation has a bimodal distribution,
the first peak is in infancy and the second one in the fourth decade
of life. Peadiatric cases usually present with intestinal obstruction
or associated anomalies. Associated conditions include
mongolism, intestinal malrotations, duodenal atresia or webs,
tracheoesophageal fistulas and cardiac defects . Between
one half to two thirds of cases of annular pancreas in adults
remain asymptomatic. Adult annular pancreas is associated with
duodenal obstruction (60%), pancreatitis (15-50%) and peptic
ulceration (26-48%) .
Pancreatitis due to annular pancreas generally involves the
annulus and the adjoining pancreatic head, preserving the body
and tail of the gland . This is probably attributed to inability
of pancreatic secretions to flow through the Santorini duct, where
as the main pancreatic duct allows the flow of secretions from the
body and tail of the pancreas to remain intact . This patient had 30% necrosis of head and proximal body which corresponds
to the above explanation.
The diagnosis is most likely of exclusion after eliminating
other common causes of pancreatitis. The related inflammation
of the annulus may cause an obstruction of the encircled
duodenum. CT showed edema of the annulus which might be
the reason for episodes of bilious vomiting in our patient. The
patients usually respond well to medical treatment as in our
case. Pancreaticoduodenectomy has been recommended only
when anannular pancreas is associated with pancreaticolithiasis
complicated by chronic pancreatitis which might warrant further
follow-up to look for progression of the disease .
RIR, though a very rare anomaly, is usually asymptomatic
unless complicated by volvulus or internal herniation. An
intestinal anomaly detected is usually associated with other
anomalies like pancreatic fusion anomaly among others, so
a thorough evaluation of these patients is warranted. The
presentation of these anomalies can vary across a spectrum: from
being asymptomatic to presenting with acute severe pancreatitis
or intestinal obstruction due to Annular Pancreas. Malrotation of
the gut has been associated with the above condition but is usually
an incidental finding in adults. A combination of reverse intestinal
rotation with annular pancreas is yet unreported in adults to
our knowledge and the possibility needs to be considered by