AT THE FOCAL POINT Lawrence J. Brandt, MD, Associate Editor for Focal Points
Duodenal stent placement for duodenal obstruction caused by pancreatic cancer associated with annular pancreas
A 55-year-old woman was admitted to our institution with a 2-week history of persistent postprandial nausea and vomiting. CT showed a fluid-filled stomach, a mass in the pancreatic head with liver metastases, and pancreatic parenchyma encircling the descending part of the duodenum (A, B). MRCP demonstrated a ring-shaped pancreatic duct encircling the descending duodenum, and EUS confirmed a hypoechoic mass in the pancreatic head invading the duodenal lumen. EUS-FNA confirmed annular pancreas and coexisting adenocarcinoma. Because of the liver metastasis, surgical treatment was not indicated, and we tried to perform duodenal stent placement. On duodenoscopy, massive distention of the stomach and stenosis of the descending part of the duodenum were observed (C). Because of a pinhole-like stenosis, we could not pass the endoscope. Hypotonic duodenography confirmed narrowing of the descending duodenum and an uncovered, self-expandable metal stent (22 60 mm, www.giejournal.org
duodenal WallFlex, Boston Scientific, Natick, Mass) was placed (D). DISCLOSURE All authors disclosed no financial relationships relevant to this article. Takeshi Ogura, MD, PhD, Daisuke Masuda, MD, PhD, Second Department of Internal Medicine, Yoshitaka Kurisu, MD, PhD, Second Department of Pathology, Akira Imoto, MD, PhD, Michiaki Takii, MD, PhD, Second Department of Internal Medicine, Kazuhisa Uchiyama, MD, PhD, Department of General and Gastroenterological Surgery, Kazuhide Higuchi, MD, PhD, Second Department of Internal Medicine, Osaka Medical College, Osaka, Japan http://dx.doi.org/10.1016/j.gie.2014.04.011
Volume
-,
No.
-
: 2014 GASTROINTESTINAL ENDOSCOPY 1
At the Focal Point
Commentary Annular pancreas (AP, meaning ring shaped) results from an unusual and extremely rare embryonic error (incomplete rotation of the ventral pancreatic bud, which is the progenitor of the head and uncinate portion) and often results in circumferential encasement of the descending duodenum by the gland. Although the actual mechanism is unproved, multiple theories exist. The German pancreatologist Lecco postulated more than a century ago that the ventral bud simply adheres to the duodenal wall before rotation and stays put while the bowel rotates (like the Enchufla move, if you dance salsa), whereas Baldwin believed the left aspect of the bud simply hypertrophied (weight gain/lazy/you don’t want to dance with them!). Despite its often ominous radiographic appearance, AP has a highly variable clinical course that probably relates to the severity of the duodenal stenosis. Although most patients remain asymptomatic, those afflicted by the sequelae of AP do not develop symptoms until around the time they are confronted with other mid-life crises, like when their AARP membership card arrives in the mail. I can’t explain this delayed phenomenon; however, the human digestive endoderm, rotational errors and all, has fully formed by late adolescence. In addition to gastric outlet obstruction, patients can have recurrent, and eventually chronic, pancreatitis and on occasion obstructive jaundice develops. Although AP is not associated with pancreatic cancer per se, focal fibrosis of the gland can masquerade as, hide, or even promote ampullary cancer. In such cases, an extensive effort to rule out malignancy should be undertaken, including side-viewing endoscopy and EUS-FNA. AP should be considered if contrast-enhanced CT reveals focal narrowing of the descending duodenum or if an upper GI series identifies an annular filling defect across the second portion of the duodenum, symmetrical dilation of the proximal duodenum, or reverse peristalsis of the segment proximal to the annulus. Definitive management is surgical and includes bypass by duodenojejunostomy or gastrojejunostomy. A recent Focal Point covered in broad strokes the technique of duodenal stenting. We hope that this case reminds you to consider both congenital causes, and the usual acquired suspects, when grappling with a patient’s complex small-bowel obstruction. David Robbins, MD, MSc Assistant Editor for Focal Points
2 GASTROINTESTINAL ENDOSCOPY Volume
-,
No.
-
: 2014
www.giejournal.org
Duodenal stent placement for duodenal obstruction caused by pancreatic cancer associated with annular pancreas
A 55-year-old woman was admitted to our institution with a 2-week history of persistent postprandial nausea and vomiting. CT showed a fluid-filled stomach, a mass in the pancreatic head with liver metastases, and pancreatic parenchyma encircling the descending part of the duodenum (A, B). MRCP demonstrated a ring-shaped pancreatic duct encircling the descending duodenum, and EUS confirmed a hypoechoic mass in the pancreatic head invading the duodenal lumen. EUS-FNA confirmed annular pancreas and coexisting adenocarcinoma. Because of the liver metastasis, surgical treatment was not indicated, and we tried to perform duodenal stent placement. On duodenoscopy, massive distention of the stomach and stenosis of the descending part of the duodenum were observed (C). Because of a pinhole-like stenosis, we could not pass the endoscope. Hypotonic duodenography confirmed narrowing of the descending duodenum and an uncovered, self-expandable metal stent (22 60 mm, www.giejournal.org
duodenal WallFlex, Boston Scientific, Natick, Mass) was placed (D). DISCLOSURE All authors disclosed no financial relationships relevant to this article. Takeshi Ogura, MD, PhD, Daisuke Masuda, MD, PhD, Second Department of Internal Medicine, Yoshitaka Kurisu, MD, PhD, Second Department of Pathology, Akira Imoto, MD, PhD, Michiaki Takii, MD, PhD, Second Department of Internal Medicine, Kazuhisa Uchiyama, MD, PhD, Department of General and Gastroenterological Surgery, Kazuhide Higuchi, MD, PhD, Second Department of Internal Medicine, Osaka Medical College, Osaka, Japan http://dx.doi.org/10.1016/j.gie.2014.04.011
Volume
-,
No.
-
: 2014 GASTROINTESTINAL ENDOSCOPY 1
At the Focal Point
Commentary Annular pancreas (AP, meaning ring shaped) results from an unusual and extremely rare embryonic error (incomplete rotation of the ventral pancreatic bud, which is the progenitor of the head and uncinate portion) and often results in circumferential encasement of the descending duodenum by the gland. Although the actual mechanism is unproved, multiple theories exist. The German pancreatologist Lecco postulated more than a century ago that the ventral bud simply adheres to the duodenal wall before rotation and stays put while the bowel rotates (like the Enchufla move, if you dance salsa), whereas Baldwin believed the left aspect of the bud simply hypertrophied (weight gain/lazy/you don’t want to dance with them!). Despite its often ominous radiographic appearance, AP has a highly variable clinical course that probably relates to the severity of the duodenal stenosis. Although most patients remain asymptomatic, those afflicted by the sequelae of AP do not develop symptoms until around the time they are confronted with other mid-life crises, like when their AARP membership card arrives in the mail. I can’t explain this delayed phenomenon; however, the human digestive endoderm, rotational errors and all, has fully formed by late adolescence. In addition to gastric outlet obstruction, patients can have recurrent, and eventually chronic, pancreatitis and on occasion obstructive jaundice develops. Although AP is not associated with pancreatic cancer per se, focal fibrosis of the gland can masquerade as, hide, or even promote ampullary cancer. In such cases, an extensive effort to rule out malignancy should be undertaken, including side-viewing endoscopy and EUS-FNA. AP should be considered if contrast-enhanced CT reveals focal narrowing of the descending duodenum or if an upper GI series identifies an annular filling defect across the second portion of the duodenum, symmetrical dilation of the proximal duodenum, or reverse peristalsis of the segment proximal to the annulus. Definitive management is surgical and includes bypass by duodenojejunostomy or gastrojejunostomy. A recent Focal Point covered in broad strokes the technique of duodenal stenting. We hope that this case reminds you to consider both congenital causes, and the usual acquired suspects, when grappling with a patient’s complex small-bowel obstruction. David Robbins, MD, MSc Assistant Editor for Focal Points
2 GASTROINTESTINAL ENDOSCOPY Volume
-,
No.
-
: 2014
www.giejournal.org
