Bariatric surgery: normal appearance and complications
In the surgical treatment of obesity, stomach anatomy changes drastically. It is important for a radiologist to know the expected norm and typical complications:
- Sleeve gastrectomy (Sleeve gastrectomy): normally, radiographs show the tubular anatomy of the narrowed stomach. Complications include suture line leaks (Sleeve leak) with contrast extravasation beyond the contour (most often in the gastric fundus region) and bleeding/hematomas (visualized on MDCT as hyperattenuating collections to the left of the staple line).
- Roux-en-Y gastric bypass (Roux-en-Y gastric bypass): a small gastric pouch is formed with free passage of barium into the efferent limb. Complications: marginal ulcer (contrast pooling in the ulcer crater of the proximal alimentary limb), internal hernia (dilatation of small bowel loops due to a mesenteric defect), and biliopancreatic limb obstruction (marked fluid distension of the excluded part of the stomach due to stricture).
- Gastric banding (Gastric band): normally, the band is positioned diagonally. The main issue is band slippage (Band slippage). With posterior slippage, the pouch is located posteriorly and inferiorly, and with anterior slippage, anteriorly and superiorly. The most severe complication is band erosion through the gastric wall, leading to obstruction, peritonitis, and sepsis.
Non-bariatric interventions
Conventional surgeries were previously widely performed for peptic ulcer disease (Peptic Ulcer Disease). These include partial gastrectomy (antrectomy combined with vagotomy and anastomosis formation).
Main types of interventions:
- Billroth I and Billroth II resections: the stomach is shortened. Following Billroth I, a gastroduodenostomy is visible on imaging.
- Pyloroplasty (Pyloroplasty): widening of the pylorus to improve gastric emptying. The pylorus loses its normal contours, and a saccular deformation is possible.
- Fundoplication (Fundoplication): an antireflux operation. It creates a deformation of the cardia. A 360-degree circular wrap (Nissen), a 270-degree posterior wrap (Toupet), and a 180-degree anterior wrap (Dor) are distinguished.
- Whipple procedure (Whipple procedure): a complex operation including partial gastrectomy, gastroenterojejunostomy, and biliary anastomoses.
Specific postoperative syndromes
Complications of conventional surgery are divided into early and delayed.
In the first 2 weeks, duodenal stump blowout or anastomotic leakage is the most dangerous (occurring in 15% of cases). It is diagnosed by oral administration of a water-soluble contrast agent. Submucosal hemorrhage (usually resolves within 10 days) and ischemia leading to necrosis and fistulas are also possible.
Late functional and structural disorders:
- Afferent loop syndrome: often caused by herniation through a transverse mesocolon defect. Radiologically: preferential filling of the loop, barium retention, and its regurgitation back into the stomach. Clinically accompanied by bilious vomiting and steatorrhea.
- Efferent loop obstruction: spasm and inflammation between days 5 and 10. Usually resolves spontaneously.
- Bezoars (Bezoars): accumulations of hardened fibrous debris. Frequently form after Billroth I and II (especially with vagotomy). On imaging—mobile masses within the lumen unevenly coated with contrast.
- Jejunogastric intussusception: prolapse of bowel loops (in 75% of cases, the efferent loop) into the anastomotic area.
Primary remnant cancer and modern imaging modalities
Special attention requires primary gastric remnant cancer, developing in patients with atrophic gastritis (up to 11% of cases). On radiographs, it manifests as decreased distensibility of the remnant, fold thickening, intraluminal masses or ulcers, as well as obstruction.
Interest in MDCT has revived for assessing disorders of the operated stomach. The development of high-resolution multiplanar MDCT has made the accuracy of non-invasive cancer diagnosis comparable to endoscopy. In the future, the introduction of PET-CT report standardization for staging and an increasing role of MRI as a safe, radiation-free alternative are expected.
Briefly: answers to topical questions
What is the anatomical difference between Billroth I and Billroth II resections?
The anatomical difference lies in the type of anastomosis formed after gastric resection.
| Type of surgery | Anatomical features |
|---|---|
| Billroth I (Billroth I) | The stomach is shortened due to antrectomy, a gastroduodenostomy is created |
| Billroth II (Billroth II) | A gastrojejunostomy (gastroenteroanastomosis) is formed between the gastric remnant and the jejunum |
What is removed and what anastomoses are formed during the Whipple procedure?
During the Whipple procedure (Whipple procedure), a pancreatoduodenectomy is performed with removal of part of the stomach and the head of the pancreas.
Formed anastomoses:
- Gastrojejunostomy — connection of the gastric remnant to the bowel.
- Cholecystojejunostomy or choledochojejunostomy — biliary-enteric anastomosis (biliary-enteric anastomosis).
- Pancreatojejunostomy — pancreatojejunal anastomosis following resection of the pancreatic head.
What anatomical types of internal hernias exist after a Roux-en-Y gastric bypass?
Following a Roux-en-Y gastric bypass, several anatomical types of internal hernias (Internal hernias) occur in specific spaces.
- Transverse mesocolon hernia — herniation of loops through a surgically created defect in the mesentery (transverse mesocolon defect) during a retrocolic approach.
- Jejunojejunostomy mesenteric hernia — hernia formation through a defect in the area of the enteroenterostomy.
- Peterson's hernia (Peterson hernia) — herniation into the space posterior to the Roux limb.
How does the radiological appearance of afferent and efferent loop obstruction differ?
The radiological appearance depends on which loop has impaired contrast passage.
| Abnormal | Radiological signs |
|---|---|
| Afferent loop obstruction (Afferent loop obstruction) | Preferential filling of the loop with contrast, barium retention on delayed images, regurgitation of contrast from the loop back into the stomach |
| Efferent loop obstruction (Efferent loop obstruction) | Delayed passage of contrast through the efferent loop |
To memorize the types of fundoplication wraps: "Nissen — 360°, Toupet — Three-quarters (270°), Dor — Half as much (180°)".
Class and exam questions
Where does contrast leakage typically occur after sleeve gastrectomy?
Along the proximal segment of the staple line, localized in the region of the gastric fundus.
What is the difference in the clinical presentation of afferent and efferent loop obstruction?
Afferent loop obstruction is often chronic in nature, causing stasis, weight loss, and bilious vomiting. Efferent loop obstruction occurs acutely on days 5–10 due to spasm and often resolves spontaneously.
Which contrast agent is safe when anastomotic leakage is suspected?
A water-soluble contrast agent is used, as leakage of barium sulfate into the abdominal cavity causes severe peritonitis.
What else to study on this topic
- CT appearance of internal hernias after Roux-en-Y gastric bypass.
- Differential diagnosis algorithm for bezoars and intraluminal gastric cancer.
- X-ray anatomy of the cuffs in antireflux procedures (Nissen, Toupet, Dor).
- Band slip: CT imaging features and patient management strategy.
Master the entire topic in the "Diagnostic Radiology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "The Operated Stomach" and 2,199 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 10 video lessons on the subject
Other topics in the section "Diagnostic Radiology of the Abdominal Organs"
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.