Introduction
An intraluminal duodenal diverticulum (“windsock” diverticulum) is a rare congenital
abnormality related to an incomplete recanalization of the foregut during embryonic
development and resulting in a duodenal diaphragm or web. Years of peristalsis lead
to the development of a pulsion-like diverticulum centrally from the duodenal web
[1]
[3]. Symptoms usually appear after the age of 30 and are nonspecific including nausea,
early satiety, or abdominal pain. Rare presentations are acute pancreatitis, acute
upper gastrointestinal bleeding or upper gastrointestinal obstruction [2]
[3]. It was first described by Silock in 1885 [1].
Case report
A 72-year-old woman was admitted to our unit with worsening abdominal pain, dark urine,
and vomiting 6 days after laparoscopic cholecystectomy for acute calculous cholecystitis.
Laboratory work-up revealed elevated liver enzymes, C-reactive protein (CRP), and
lipase levels. Abdominal ultrasound showed a dilated common bile duct (CBD), slight
pancreatic edema, and a biloma in the gallbladder bed. A computed tomography (CT)
scan confirmed the findings and a cystic tumor mass was suspected in the duodenum
at the level of the ampulla of Vater ([Fig. 1], [Fig. 2]). Magnetic resonance cholangiopancreatography (MRCP) showed a small (5 mm) stone
in the CBD ([Fig. 3]). The patient was scheduled for endoscopic retrograde cholangiopancreatography (ERCP).
A double lumen was seen in the second portion of the duodenum, corresponding to a
large saccular structure surrounded on both sides by normal mucosa ([Fig. 4], [Video 1]). The papillary orifice was difficult to find at the level of the septum ([Fig. 5]). Cholangiography showed a dilated CBD and intrahepatic ducts, stenosis at the level
of the papilla, and no leakage from the cystic duct stump. Biliary sphincterotomy
followed by papillary large balloon dilation to 12 mm was performed. Balloon sweeps
did not show any stones. The procedure was followed by duodenal exploration using
a standard gastroscope and showing the diverticulum ([Video 1]). The condition of the patient rapidly improved. Two weeks later, the biloma had
completely disappeared.
Fig. 1 Computed tomography (CT) scan showing dilated common bile duct (CBD) and biloma in
the gallbladder bed.
Fig. 2 Computed tomography (CT) scan showing a suspected cystic tumor mass at the level
of the ampulla of Vater.
Fig. 3 Magnetic resonance cholangiopancreatography (MRCP) demonstrating the biloma and a
small stone in the common bile duct (CBD).
Fig. 4 Double lumen in the second portion of the duodenum.
Video 1 Duodenoscopy showing double lumen in the second portion of the duodenum, cannulation
of the common bile duct (CBD), biliary sphincterotomy, endoscopic papillary large
balloon dilation, balloon sweeps of the CBD, and duodenal exploration using a standard
gastroscope.
Fig. 5 Papillary orifice.
Discussion
An intraduodenal diverticulum (“windsock” diverticulum) is a rare condition, which
can be difficult to diagnose. The typical endoscopic finding is a double lumen in
the second portion of the duodenum just below the level of the papilla of Vater. The
endoscopic appearance may be challenging – the diverticulum may be collapsed and missed
or a long sack may be mistaken for the duodenal lumen. An inverted diverticulum may
appear like a tumor or large polyp. Differential diagnosis includes a distal choledochocele,
periampullary cystic mass, or duodenal duplication cyst. Duplication cysts have no
communication with the lumen and are situated in the periduodenal space. The intraduodenal
diverticulum has a visible communication with the duodenal lumen ([Fig. 6]). The diagnosis can be confirmed by an upper gastrointestinal series, CT with pancreatic
protocol, or magnetic resonance imaging (MRI). Possible findings from CT scan are
a periampullary mass, or a saccular structure with air-fluid level or oral contrast
(when used), communicating with the duodenal lumen. When oral contrast is used, the
wall of the diverticulum can be seen as a low-density “flap”. A collapsed or inverted
diverticulum can mimic an intraluminal tumor mass or polyp, or be seen as circumscribed
wall thickening. However, imaging modalities can show conflicting results as a result
of the possibility of the lesion collapsing or expanding to change its appearance
[3]
[5]. Surgical diverticulectomy is the traditional treatment for symptomatic patients
[4]. Endoscopic snare resection or needle-knife diverticulotomy are also possible [1].
Fig. 6 Drawing demonstrating the anatomy of the intraduodenal diverticulum.
This case is unusual because of the late presentation of the congenital condition
with biliary obstruction after cholecystectomy and the conflicting results of the
imaging modalities. ERCP with biliary sphincterotomy was the appropriate method to
solve the problem; however, ERCP can be challenging because of difficulties in finding
the papillary orifice and CBD cannulation as a result of the unpredictable location
of the intraduodenal portion of the CBD.
