Figure 1
Upright abdominal radiograph
Upright abdominal radiograph shows a diffuse absence of bowel air with a few air-fluid levels epigastric, peri-umbilical and in the right abdominal region
Internal herniation with bowel ischemia after Roux-en-Y gastric bypass surgery.
SectionAbdominal imaging
Case TypeClinical Cases
AuthorsPeters B, Waked K, Vanhoenacker FM, Ceulemans J, Mespreuve M
Connected authors
71 years, male
Clinical History
A 71-year-old male presented with acute abdominal pain, severe bloating and constipation. The patient underwent a laparoscopic Roux-en-Y gastric bypass (RYGB) 20 years previously. Clinical examination showed diffuse abdominal tenderness and dull abdominal percussion. Blood samples showed a slightly elevated lactate of 1,65 mmol/L (0, 5-1, 6 mm/L) with normal inflammatory parameters.
Imaging Findings
An upright abdominal radiograph showed overall decrease of bowel air with few air-fluid levels in the epigastrium and right hemiabdomen (Fig. 1). A subsequent contrast enhanced computed tomography (CE CT) of the abdomen was performed.
The images showed a diffuse enlargement of small bowel loops filled with fluid, diffuse haziness of the surrounding fat (Fig. 2 and 3) and free abdominal fluid. Some bowel loops showed a thin wall with decreased contrast enhancement compared to other loops, suggestive of bowel ischemia (Fig 2). There was no free air. Axial images showed a mushroom configuration of the bowel loops and adjacent mesentery (Fig. 4) whereas coronal images showed a swirled mesentery (Fig. 5).
The diagnosis of internal herniation (IH) with bowel ischemia was made. Emergency surgery confirmed a transmesocolic internal herniation with abdominal obstruction and reversible bowel ischemia. Reduction was successful.
The images showed a diffuse enlargement of small bowel loops filled with fluid, diffuse haziness of the surrounding fat (Fig. 2 and 3) and free abdominal fluid. Some bowel loops showed a thin wall with decreased contrast enhancement compared to other loops, suggestive of bowel ischemia (Fig 2). There was no free air. Axial images showed a mushroom configuration of the bowel loops and adjacent mesentery (Fig. 4) whereas coronal images showed a swirled mesentery (Fig. 5).
The diagnosis of internal herniation (IH) with bowel ischemia was made. Emergency surgery confirmed a transmesocolic internal herniation with abdominal obstruction and reversible bowel ischemia. Reduction was successful.
Discussion
The RYGB is the most common bariatric procedure and consists of three steps: creation of a small stomach pouch, reconstruction of a new gastrojejunal anastomosis between the stomach pouch and the jejunum (Roux limb) and construction of a jejunojejunostomy (biliopancreatic limb). This altered anatomy creates intermesenteric spaces through which the small bowel may herniate and cause bowel ischemia and even death. IH has a reported prevalence of up to 14% and is more common after laparoscopic RYGB because of less adhesion formation, compared to open surgery [1, 2]. There are two intermesenteric spaces where IH may occur (Fig 6): at the jejunojejunostomy between the biliopancreatic and Roux limb (jejunojejuno mesenteric space) and between the Roux limb and the transverse mesocolon (Peterson space). An additional site for IH, only in case of retrocolic placement of the Roux limb, is in the transverse mesocolon through which the Roux limb passes. It has been reported that antecolic placement of the Roux limb and perioperative closure of the mesenteric and Peterson spaces may reduce the risk of IH [3].
Clinical signs and symptoms of internal herniation are nonspecific. The most common symptoms are nausea, vomiting, abdominal pain, and abdominal distention.
Abdominal radiography is nonspecific and may show dilated small bowel with air-fluid levels and crowding in abnormal location. CT is considered to be the gold standard for the correct diagnosis of IH. Multiphasic CT is advisable. Non-enhanced images may show hemorrhagic bowel congestion and hyperattenuation of the bowel wall. The arterial phase allows the evaluation of the mesenteric arteries. The portal venous phase is the most valuable for the evaluation of the bowel wall and the mesenteric vessels.
Administration of oral contrast is controversial and should not be used in routine. Oral contrast may hide spontaneous bowel wall hyperdensity and reduces the accuracy of bowel wall enhancement. Lockhart et al. investigated the sensitivity and specificity of seven CT signs of internal herniation: swirled mesentery, mushroom, hurricane eye, small-bowel obstruction, clustered loops, small-bowel behind superior mesenteric artery, right-sided anastomosis and “overall impression ”. Swirled mesentery is the best predictor of IH with a sensitivity of 61-83% and specificity of 67-94% [4, 5].
The treatment of IH after RYGB consists of reduction of the herniated small bowel and closure of both intermesenteric spaces. In case of irreversible ischemia, a part of the small bowel has to be resected. Most often IH is treated laparoscopically.
Clinical signs and symptoms of internal herniation are nonspecific. The most common symptoms are nausea, vomiting, abdominal pain, and abdominal distention.
Abdominal radiography is nonspecific and may show dilated small bowel with air-fluid levels and crowding in abnormal location. CT is considered to be the gold standard for the correct diagnosis of IH. Multiphasic CT is advisable. Non-enhanced images may show hemorrhagic bowel congestion and hyperattenuation of the bowel wall. The arterial phase allows the evaluation of the mesenteric arteries. The portal venous phase is the most valuable for the evaluation of the bowel wall and the mesenteric vessels.
Administration of oral contrast is controversial and should not be used in routine. Oral contrast may hide spontaneous bowel wall hyperdensity and reduces the accuracy of bowel wall enhancement. Lockhart et al. investigated the sensitivity and specificity of seven CT signs of internal herniation: swirled mesentery, mushroom, hurricane eye, small-bowel obstruction, clustered loops, small-bowel behind superior mesenteric artery, right-sided anastomosis and “overall impression ”. Swirled mesentery is the best predictor of IH with a sensitivity of 61-83% and specificity of 67-94% [4, 5].
The treatment of IH after RYGB consists of reduction of the herniated small bowel and closure of both intermesenteric spaces. In case of irreversible ischemia, a part of the small bowel has to be resected. Most often IH is treated laparoscopically.
Differential Diagnosis List
Internal herniation with bowel ischemia
Obstruction due to intestinal adhesions
Obstruction due to malignancy
Volvulus
Final Diagnosis
Internal herniation with bowel ischemia
References
[1] Iannelli A, Facchiano E, Gugenheim J (2006) Internal hernia after laparoscopic Roux-en-Y gastric bypass for morbid obesity. Obes Surg 16(10):1265-1271 (PMID: 17059733)
[2] Garrard CL, Clements RH, Nanney L, Davidson JM, Richards WO (1999) Adhesion formation is reduced after laparoscopic surgery. Surg Endosc 13(1):10-13 (PMID: 9869679)
[3] Geubbels N, Lijftogt N, Fiocco M, van Leersum NJ, Wouters MWJM, de Brauw LM (2015) Meta-analysis of internal herniation after gastric bypass surgery. Br J Surg 102(5):451-460 (PMID: 25708572)
[4] Doishita S, Takeshita T, Uchima Y, Kawasaki M, Shimono T, Yamashita A, Sugimoto M, Ninoi T, Shima H, Miki Y (2016) Internal Hernias in the Era of Multidetector CT: Correlation of Imaging and Surgical Findings. RadioGraphics 36(1):88-106 (PMID: 26587890)
[5] Lockhart ME, Tessler FN, Canon CL, Smith JK, Larrison MC, Fineberg NS, Roy BP, Clements RH (2007) Internal hernia after gastric bypass: sensitivity and specificity of seven CT signs with surgical correlation and controls. AJR Am J Roentgenol 188(3):745-50 (PMID: 17312063)
Case information
| URL: | https://www.eurorad.org/case/14127 |
| DOI: | 10.1594/EURORAD/CASE.14127 |
| ISSN: | 1563-4086 |
License
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Figure 2
CE CT of the abdomen
Axial CE CT of the abdomen shows enlarged small bowel loops with thin walls and decreased contrast enhancement (white arrows) compared to normal loops (blue arrows). Note the free paracolic fluid on both sides.
Axial CE CT of the abdomen shows enlarged small bowel loops with thin walls and decreased contrast enhancement (white arrows) compared to normal loops (blue arrows). Note the free paracolic fluid on both sides.
Figure 3
CE CT of the abdomen
Coronal CE CT of the abdomen shows a diffuse haziness of the herniated mesentery (arrows)
Figure 4
CE CT of the abdomen
Axial CE CT of the abdomen shows the mushroom sign (red line).
Figure 5
CE CT of the abdomen
Coronal CE CT of the abdomen shows a swirled mesentery (arrow).
Figure 6
Illustration
The different intermesenteric internal herniation sites after Roux-en-Y gastric bypass surgery: 1 = transmesocolic hernia, 2 = jejunojejunostomy mesenteric hernia, 3 = Petersen hernia [4].
Upright abdominal radiograph
Upright abdominal radiograph shows a diffuse absence of bowel air with a few air-fluid levels epigastric, peri-umbilical and in the right abdominal region
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
CE CT of the abdomen
Axial CE CT of the abdomen shows enlarged small bowel loops with thin walls and decreased contrast enhancement (white arrows) compared to normal loops (blue arrows). Note the free paracolic fluid on both sides.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
Axial CE CT of the abdomen shows enlarged small bowel loops with thin walls and decreased contrast enhancement (white arrows) compared to normal loops (blue arrows). Note the free paracolic fluid on both sides.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
CE CT of the abdomen
Coronal CE CT of the abdomen shows a diffuse haziness of the herniated mesentery (arrows)
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium.
CE CT of the abdomen
Axial CE CT of the abdomen shows the mushroom sign (red line).
Image origin: Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium
Image origin: Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium
CE CT of the abdomen
Coronal CE CT of the abdomen shows a swirled mesentery (arrow).
Image origin: Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium
Image origin: Vanhoenacker F, Department of Radiology, AZ Sint Maarten, Mechelen, Belgium
Illustration
The different intermesenteric internal herniation sites after Roux-en-Y gastric bypass surgery: 1 = transmesocolic hernia, 2 = jejunojejunostomy mesenteric hernia, 3 = Petersen hernia [4].
(C) Doishita S, Takeshita T, Uchima Y, et al. Internal Hernias in the Era of Multidetector CT: Correlation of Imaging and Surgical Findings. RadioGraphics. 2016;36(1):88-106.
(C) Doishita S, Takeshita T, Uchima Y, et al. Internal Hernias in the Era of Multidetector CT: Correlation of Imaging and Surgical Findings. RadioGraphics. 2016;36(1):88-106.