Case presentation
The 52-years-old Japanese man who had undergone laparoscopic surgery for
a duodenal ulcer 12 years ago presented with upper abdominal pain. His
symptoms persisted from the morning of that day. On arrival at the
emergency room, his blood pressure was 166/92 mmHg, pulse was 65 beats
per minute, and oxygen saturation was 98% on room air. He experienced
mild discomfort, with a body temperature of 39.0 °C. No signs of
peritoneal irritation were noted. The laboratory data showed a high
white blood cell count of 21,200/uL but c-reactive protein level of 0.3
mg/dL was at normal level (<1.0 mg/dL). Abdominal computed tomography
(CT) revealed an expanded duodenal diverticulum inside the second
portion of the duodenum and free air in the retroperitoneum outside the
diverticulum (Fig. 1). Duodenal ulcer perforation was suspected based on
the patient’s history. However, CT imaging was most likely caused by
perforation of a duodenal diverticulitis because past CT showed an
existing duodenal diverticulum. Because there were no symptoms of
peritoneal irritation, broad-spectrum antibiotics, placement of a
nasogastric tube, and use of proton pump inhibitors (PPIs) were
initiated. After 2 days of admission, the inflammatory findings did not
improve; therefore, endoscopic drainage was performed. On endoscopy, a
duodenal diverticulum with a fixed large phytobezoar and a large amount
of pus was observed (Fig. 2a). Because the bezoar blocked the orifice of
the duodenal diverticulum, it perforated the retroperitoneum and became
an abscess cavity. The phytobezoar was so large and of hard consistency
that endoscopic removal during a single session was difficult. A 7.5 Fr
endoscopic nasobiliary drainage (ENBD) catheter was placed in the
duodenal diverticulum. Contrast injection showed a large translucent
image of the diverticulum (Fig. 3a). The duodenal diverticulum was
washed daily with 20 mL of saline from the ENBD catheter. As a result,
the fever resolved and inflammatory findings improved. On the second
endoscopy, since the phytobezoar was slightly softer than that on the
previous endoscopy, it was gradually eliminated by crushing with forceps
(Fig. 2b). However, part of the phytobezoar remaining deep in the cavity
could not be completely removed, so a 6 Fr ENBD catheter was placed in
the cavity again (Fig. 3b). The following day, saline was injected
through the tube to clean the abscess cavity, and the phytobezoar was
completely removed by a third endoscopic treatment (Fig. 2c). The
patient was discharged from the hospital without any complications.
After 3 months, subsequent upper gastrointestinal endoscopy showed that
the cavity of the duodenal diverticulum had shrunk and the mucosa of the
diverticulum had regenerated (Fig. 2d).