Imaging findings in complications of bariatric surgery.

Imaging findings in complications of bariatric surgery. Poster No.: C-1791 Congress: ECR 2012 Type: Educational Exhibit Authors: A. Fernandez Alfonso, G. Anguita Martinez, D. C. Olivares Morello, C. García Villafañe, J. Gonzalez Nieto, M. M. Moreu, A. Cardenas, P. Rodriguez Carnero; Madrid/ES Keywords: Abdomen, Emergency, Gastrointestinal tract, CT, Fluoroscopy, Diagnostic procedure, Complications, Acute, Obstruction / Occlusion, Fistula DOI: 10.1594/ecr2012/C-1791 Any information contained in this pdf file is automatically generated from digital material submitted to EPOS by third parties in the form of scientific presentations. References to any names, marks, products, or services of third parties or hypertext links to thirdparty sites or information are provided solely as a convenience to you and do not in any way constitute or imply ECR's endorsement, sponsorship or recommendation of the third party, information, product or service. ECR is not responsible for the content of these pages and does not make any representations regarding the content or accuracy of material in this file. As per copyright regulations, any unauthorised use of the material or parts thereof as well as commercial reproduction or multiple distribution by any traditional or electronically based reproduction/publication method ist strictly prohibited. You agree to defend, indemnify, and hold ECR harmless from and against any and all claims, damages, costs, and expenses, including attorneys' fees, arising from or related to your use of these pages. Please note: Links to movies, ppt slideshows and any other multimedia files are not available in the pdf version of presentations. www.myesr.org Page 1 of 15

Learning objectives To be familiarized with the radiographic manifestations of normal anatomy and major complications after bariatric surgery with examples of most frequent used procedures in our hospital. Background Morbid obesity is a chronic disease with an increasing prevalence and is associated with several morbidities. Bariatric surgery is an effective surgical intervention that can produce dramatic weight loss in morbidly obese patients. Procedures for weight reduction can be divided into three categories: gastric restriction, intestinal malabsorption and a combination of both techniques. Purely restrictive therapies are generally less complex (ie, technically easier to perform with less potential for serious complications) but may produce less weight loss and have more long-term failures. Malabsorptive procedures creates bypass portions of small bowel, limiting food digestion and absorption to a short segment of ileum. There is potential for metabolic complications including intermittent diarrhea and steatorrhea due to malabsorption. In our hospital most frequent used procedures are lapararoscopic sleeve gastrectomy, Roux-en-Y gastric bypass and biliopancreatic diversion with duodenal switch. -In sleeve gastrectomy (fig. 1) is created a small gastric pouch to induce weight loss through satiety effects. -In Roux-en-Y gastric bypass (fig. 2), a small gastric pouch (15-30 ml) is created from the proximal stomach. A side-to-side anastomosis is made between the pouch and the Roux limb. The Roux limb is generally 75-150 cm long. Since the bypassed stomach and duodenum remain intact, a jejunojejunostomy is required to re-establish continuity. -In biliopancreatic diversion with duodenal switch (fig. 3) the restrictive portion of the surgery is a sleeve gastrectomy in which the greater curvature portion of the stomach is resected, creating a gastric tube. Malabsorption is achieved by transecting the proximal duodenum and connecting the ileum to the postpyloric duodenum. This results in two sections of small bowel; the alimentary limb and biliopancreatic limb which are connected distally to create a relatively short common limb that enters the colon. Images for this section: Page 2 of 15

Fig. 1: Sleeve gastretomy Page 3 of 15

Fig. 2: Roux-en-Y gastric bypass; yeyunoyeyunostomy (small arrow) gastroyeyunostomy (large arrow) and Page 4 of 15

Fig. 3: Biliopancreatic diversion with duodenal switch: -alimentary limb (small arrow) pancreaticbiliary limb (large arrow) -anastomosis of ileum to duodenum (arrowhead) Page 5 of 15

Imaging findings OR Procedure details Many institutions perform routine upper gastrointestinal examinations (UGI) within 2-3 days of surgery to evaluate for anastomotic leak to determine if urgent re-exploration is necessary. After scout image acquisition, the patient swallows a small sip of a water-soluble contrast agent, which may remain in the distal esophagus and gastric pouch for a variable period (seconds to minutes) before passing the side-to-side anastomosis and filling the blind loop and alimentary limb. Delayed pouch emptying may be misconstrued as an anastomotic stenosis, but in the majority of cases it simply reflects a swollen anastomosis after surgery. The distal side-to-side anastomosis is difficult to visualize because contrast material rarely refluxes from the alimentary limb into the pancreaticobiliary limb either gastric bypass as in duodenal switch. Despite the substantial advantages of CT over upper GI series, the routine use of CT with oral contrast in the immediate postoperative course after bariatric surgery is not recommended. Therefore, helical CT should be used only in ambiguous cases where conventional radiographic studies are indeterminate or in urgent complications including: staple-line or anastomotic leaks (fig. 4, fig. 5, fig. 6). stomal stenosis (fig. 7). obstruction of the enteroenterostomy leading to acute gastric distention (fig. 8). staple-line disruption with comunication between pouch and defunctionalized stomach (fig. 9). small bowel obstructions (fig. 10) due to adhesions or hernia. oclussion of the alimentary limb. abscesses and hematomas. Adequate evaluation requires radiologists to understand the surgical technique, because complex postsurgical anatomy and surgery specific complications make interpretation difficult. Images for this section: Page 6 of 15

Fig. 4: Sleeve gastrectomy with leak in staple-line (arrow in a and b) and extraluminal cumulus of oral contrast and gas (star in a and b). Page 7 of 15

Fig. 5: Roux-en-Y gastric bypass with gastroyeyunal anastomosis (arrow in a and b) leak with extraluminal cumulus of oral contrast and gas (star in a and b) (excluded stomach, curved arrow). Page 8 of 15

Fig. 6: Biliopancreatic diversion and duodenal switch with duodenal-ileal anastomosis (arrow in a and b) leak collected by drainage tube (star in a and b). Page 9 of 15

Fig. 7: Roux-en-y gastric bypass with stomal stenosis in gastroyeyunal anastomosis (arrow). Gastroyeyunal stoma is created to be approximately 12 mm in diameter. Patients with this problem tipically present with postprandial epigastric pain and vomiting. Page 10 of 15

Fig. 8: Roux-enY gastric bypass with stenosis of the enteroenteric anastomosis leading to acute gastric distention. Marked distension of defunctionalized stomach (star in a) and distension of duodenum (star in b). Bowel loops with oral contrast as part of the alimentary limb (stars in c). Enteroenteric anastomosis (arrow in d). Page 11 of 15

Fig. 9: Roux-en-y gastric bypass with comunication between gastric pouch and defunctionalized stomach (arrow in a and b). There is preferential step of oral contrast to duodenum (arrow in c and d) instead of gastroyeyunal anastomosis and alimentary limb. Page 12 of 15

Fig. 10: Roux-en-Y gastric bypass with obstruction in alimentary limb secondary to abdominal wall hernia through laparoscopic trocar hole. Gastroyeyunal anastomosis (arrow in a and b), defunctionalized stomach (curved arrow in a and b), dilated yeyunal loop (star in b, c and d ) and hernia (triangle in d). Page 13 of 15

Conclusion Radiologists are crucial in the postoperative assessment of these patients. Complications can be minimized, managed more efficiently, or prevented with prompt evaluation by the radiologist. In conclusion, it is important for the radiologist to be familiarized with the radiographic manifestations of normal anatomy and major complications after bariatric surgery. Personal Information References 1-Trenkner SW. (2009) Imaging of morbid obesity procedures and their complications. Abdominal Imaging 34:335-344. 2-Andrés M. et al. (2007) Roux-en-Y gastric bypass: mayor complications. Abdominal Imaging 32:613-618 3-Scheirey CD et al. (2006) Radiology of the laparoscopic Roux-en-Y gastric bypass procedure: conceptualization and precise interpretation of results. Radiographics 26:1355-1371 4-Merkle EM, et al. (2005) Roux-en-Y gastric bypass for clinically severe obesity: normal appearance and spectrum of complications at imaging. Radiology 234:674-683 5-Yu J, et al. (2004) Normal anatomy and complications after gastric bypass surgery: helical CT findings. Radiology 231:753-760 6-Blachar A, et al. (2002) Gastrointestinal complications of laparo- scopic Roux-en-Y gastric bypass surgery: clinical and imaging findings. Radiology 223:625-632 7-Blachar A, Federle MP (2002) Gastrointestinal complications of laparoscopic Roux-enY gastric bypass surgery in patients who are morbid obese: findings on radiography and CT. AJR 179:1437-1442 Page 14 of 15

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