Imaging features of the complications of bariatric surgery

Imaging features of the complications of bariatric surgery Poster No.: C-2173 Congress: ECR 2014 Type: Authors: Educational Exhibit M. Lahkim 1, J. Lucas 2, A. HAMEG 3, P. Lacombe 4 ; 1 Rabat/MA, 2 Neuilly/Seine/FR, 3 Paris/FR, 4 Boulogne-Billancourt/FR Keywords: DOI: Abdomen, Anatomy, CT, Fluoroscopy, Diagnostic procedure, Haemorrhage, Infection 10.1594/ecr2014/C-2173 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 21

Learning objectives -Review the surgical techniques of various types of bariatric surgery. -Define the role of fluoroscopy and CT in the diagnosis of the post-operative complications of bariatric surgeries. - getting familiar with the anatomical configuration of the post-surgical abdomen. -Recognizing the radiological findings of various post-operative complications. -correlating the fluoroscopic and CT radiological findings. Page 2 of 21

Background - Post bariatric surgery patients creates a diagnostic challenge for radiologists due to their large size, decreased mobility, and distorted postsurgical anatomy. -Practical knowledge of bariatric surgical techniques, normal postoperative anatomy and of common complications is essential for accurate image interpretation. -Indications of bariatric surgery: Bariatric surgery for weight loss is indicated for morbidly obese patients defined as patients with a BMI of 35 or greater with serious comorbidity such as cardiovascular disease, hypertension, uncontrolled diabetes or sleep apnea. Or a BMI of 40 regardless of the presence or absence of comorbidities. -Surgical techniques: Bariatric surgical techniques are categorized into two main categories: 1) Restrictive procedures: where gastric volume is reduced considerably to decrease caloric intake and providing early satiety. 2) Malabsorptive procedures: where the gastrointestinal tract is surgically altered by bypassing a portion of intestine to induce malabsorption and decrease caloric intake. 3) Combined restrictive-malabsorbtive procedures. The spectrum of procedures includes the Roux-en-Y gastric bypass (RYBP), laparoscopic adjustable gastric banding, vertical-banded gastroplasty (VBG), jejunoileal bypass, sleeve gatrectomy, biliopancreatic diversion, and biliopancreatic diversion with duodenal switch. -Imaging techniques and tips: * we use 300mg/ml Solution of TELEBRIX GASTRO (ioxitalamic acid in the form of meglumine ioxitalamate) as oral contrast material with a dose of 66, 03 g per 100ml with citrus flavor). The taste is well tolerated by patients, which allows easy use of this product. Page 3 of 21

Fluoroscopy is the procedure of choice for the diagnosis of surgical anatomy, leaks, staple line dehiscence and pouch obstruction. The following tips are suggested for fluoroscopic examinations: Study carefully the patient's file (details of the surgical procedure) Remove the nasogastric tube before administration of oral contrast. Study the stomach first: The first swallow of contrast defines anatomy, staple line dehiscence, size of the gastric proximal pouch and outflow channel. Pay special attention to the surgical drain (infrequently, the only sign of a leak is an opacification of the surgical drain) For early complications (postoperative leak, obstruction) use water soluble contrast and video fluoroscopy. For late complications (weight gain, dehiscence, pouch enlargement, ulcer) use high density barium for the initial swallows to establish anatomy. Computed tomography: (when patient size permits), is performed to localize the extent of gastrointestinal leaks, examine the bypassed loops and to identify any extra luminal complications. Here are a few tips: Use abundant oral contrast (2% iodinated contrast). Identify the staple lines and configuration of the stomach and jejunum on CT images to verify that they match expected operative anatomy. Always correlate with fluoroscopy images, this will give you a better overview of the procedure. Page 4 of 21

Images for this section: Fig. 1: jejunoileal bypass Department of radiology, Hopital AMBROISE-PARE Page 5 of 21

Fig. 2: Roux en Y Department of Radiology, Hopital AMBROISE-PARE Page 6 of 21

Fig. 3: Vertical banded gastroplasty Department of radiology, Hopital AMBROISE-PARE Page 7 of 21

Fig. 4: Sleeve Gastrectomy Department of radiology, Hopital AMBROISE-PARE Page 8 of 21

Findings and procedure details Complications of bariatric surgery Bariatric surgery has a higher complication rate than in normal weight patients. Infection due to gastrointestinal leak dominates the perioperative mortality causes. Pulmonary embolism is the second most common cause. That's why Perioperative antibiotics and low dose heparin therapy must be used routinely to reduce risk of infection and thromboembolism. Gastrointestinal leak The most serious post-operative complication and the most common cause of death due to peritonitis. Incidence: effecting 0.6% of patients after VBG and 2-5% of patients after RYGB (4). Clinical signs: the symptoms of a leak with or without peritonitis could be very subtle, both the clinician and the radiologist should have a high index of suspicion for GIT leaks. Tachycardia is the most reliable and sometimes the only sign indicating the presence of peritonitis. It could be, however, associated with other signs of peritonitis, such as: fever and abdominal pain. Any patient with unexplained tachycardia and/or fever should be investigated for perforation and peritonitis. radiological techniques and findings: Fluoroscopy: the most sensitive modality for the detection of both small and large leaks. Fluoroscopy is performed using a water soluble contrast medium. It typically shows an extravasation of contrast material into the left upper quadrant. It is also possible to see a collection of air bubbles in the left upper quadrant before the administration of contrast material (figures...). CT scan: used to further examine the extension of a leak or its complications e.g.: abscesses etc (Figures...). Gastric outlet obstruction Page 9 of 21

Incidence: 5-12% of the patients after Gastric bypass and up to 20% after VBG. Clinical signs: vomiting, gastro-esophageal reflux and signs of upper GIT obstruction. Causes: Ø Early: transient early outlet obstruction due to edema is quite common. It resolves spontaneously, without any intervention. Iatrogenic overstitching could also cause early outlet obstruction. Ø Late: develops 4-6weeks post operatively due to fibrosis or adhesions. Radiological appearance: Ø Fluoroscopic images will show dilatation of the gastric pouch and possibly a reflux of contrast material to the esophagus depending on the degree of the stenosis. There will be a delay in the passage of the contrast material through the stenosed orifice as well. Rarely, gastric diverticula of the gastric pouch could be seen. Ø Complementary CT scan images will demonstrate the same findings plus possible compression of the bypassed stomach caused by the dilation of the gastric pouch. Gastro-gastric staple line dehiscence Incidence: up to 30 to 48% of patients who undergo VBG. Clinical signs: dehiscence leads to anincrease in the outflow to the bypassed stomach, decreasing the effect of early satiety and allowing increased food intake which causes weight gain. Radiological findings: fluoroscopy is the modality of choice for the diagnosis of stable line dehiscence as it allows examination of the proximal gastric pouch, the outflow channel, and the oozing of contrast material through the defects in of the staple line before the distal stomach opacifies (figure...). In CT, It is difficult to assess whether contrast material in the remnant stomach is a result of the staple line disruption or from retrograde flow through the afferent limb which is a completely normal postoperative finding. Staple dehiscence and ulcer Page 10 of 21

* Incidence and pathophysiology: 16% of patients with staple line dehiscence develop ulcers as a consequence of the staple disruption creating a gastro gastric fistula allowing distal stomach acid to enter the proximal pouch and jejunostomy causing ulceration. Bleeding and hematoma : Probably due to bleeding vessels at staple lines or anastomoses. Clinical signs: nonspecific in the perioperative course. Imaging features: CT is the modality of choice for diagnosing patients with a dropping hematocrit after bariatric surgery to look for possible active bleeders or a hematoma. (Figure...). Internal herniation post RYGB: Occurs in 2.2% of post RYGB patients. During RYGB two mesenteric defects are created in order to one at the level of the jejunum and another in the mesocolon Caused by fast loss of fat the makes the defects in the mesentery looser. Types: Herniation of the roux limb through the mesocolon:most common type. Herniation though the mesenteric defect made for the montage of the jejunum to make the jejuno jejunal junction. Peterson hernia:herniation of the small bowl behind the roux limb. Radiological findings: 1. Clumping of bowl loops giving a sac like appearance. 2. Bird beak sign of the small bowl at its entry into the hernia sac. 3. Feces sign indicating stagnation. 4. The small intestine appearing in direct contact with the abdominal wall without overlying omental fat. 5. Central displacement of the colon by the herniated, dilated small intestinal loops. 6. Twisted and dilated mesenteric vessels. 7. Signs of small bowl obstruction +/- signs of ischemia. Page 11 of 21

adhesive obstruction May occur in bypassed loops post-jib or RYGB leading to the appearance of the classical clinical and radiological signs of small bowl obstruction. Usually requires investigation by CT scan. Complications of bypassed bowel segments Acute gastric dilatation After RYGB may cause a closed loop obstruction. Intussusception: very rare. CT shows the classic target sign. Gastritis Occurs in the bypassed stomach due to altered motility and reflux. Bleeding ulcers from the bypassed distal stomach or duodenum which frequently does not respond to H2 blockers, necessitating distal gastrectomy. Metabolic complications Gallstones occur in up to 33% of bariatric patients due to mobilization of cholesterol during weight loss. Malabsorption: the most severe metabolic disturbances result from malabsorptive procedures. After JIB, late complications include diarrhea, nephrolithiasis, cholelithiasis, liver dysfunction, liver cirrhosis, and malnutrition. Page 12 of 21

Images for this section: Fig. 5: Proximal short stenosis at a distance from the gastrojejunal anastomosis associated to dilatation of the upstream loop corresponding to the mesocolic crossing area at the CT. Hopital Ambroise -paré Page 13 of 21

Fig. 6: Proximal short stenosis at a distance from the gastrojejunal anastomosis associated to dilatation of the upstream loop corresponding to the mesocolic crossing area at the CT. Hopital Ambroise-Paré Page 14 of 21

Fig. 9: Two fluid collections in contact with stomach, containing microbubbles of gas suggesting abscesses: a drain is placed to evacuate the collections. Hopital Ambroise-Paré Page 15 of 21

Fig. 7: jejunal obstruction due to transmesocolic intern herniation, after Gastrojejunal by pass. Hopital Ambroise -paré Page 16 of 21

Fig. 8: jejunal obstruction due to transmesocolic intern herniation, after Gastrojejunal by pass. Hopital Ambroise-Paré Page 17 of 21

Fig. 10: Spontaneously dense extra gastric collection (60 UH) suggesting a hematoma.there is no leak of contrast. Hopital Ambroise-Paré Page 18 of 21

Conclusion *Understanding postsurgical anatomy in patients undergoing radiologic evaluation after bariatric surgical procedures represent a challenge to the radiologist. *Fluoroscopy seems to be the best examination available for defining operative anatomy, gastrointestinal leak, and staple line dehiscence, and it can supplement endoscopy in the evaluation of ulcer disease, while CT can be reserved for diagnosing extra luminal pathology, imaging bypassed bowel segments, and guiding interventional procedures Page 19 of 21

Personal information Thanks to Guerbet for helping to prepare this presentation. Page 20 of 21

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