Imaging following bariatric surgery: roux-en-Y gastric bypass, laparoscopic adjustable gastric banding and sleeve gastrectomy

Abstract

Morbid obesity is an increasing health problem, and bariatric surgery is a popular treatment option. Radiologists must be familiar with performing and interpreting studies in this patient population. The typical post-operative findings of the Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB) and sleeve gastrectomy (SG) procedures on upper gastrointestinal (UGI) series and computerized tomography (CT) are presented. An overview of the potential complications is provided in addition to a description of potential pitfalls in interpreting these studies.

Figure 1.

RYGB diagram. A small gastric pouch (P) is created to exclude the remainder of the stomach and the duodenum (D) (biliopancreatic limb) from the path of food. There is a gastrojejunostomy with a jejunal Roux limb (J) anastomosed to the pouch via a narrow stoma (arrowhead) and creating the alimentary limb. There is then a more downstream jejunojejunostomy (arrows). This creates an alimentary limb (i.e. pouch, Roux limb), a biliopancreatic limb (including the excluded stomach and duodenum) and a downstream common channel. RYGB, Roux-en-Y gastric bypass.

Figure 2.

Expected anatomy following gastric bypass on UGI. (a). Fluoroscopic UGI spot image acquired with the patient in the supine LPO position shows the small gastric pouch (P), narrow gastrojejunal anastomosis (arrows) and adjacent Roux jejunal limb (J). (b). Supine overhead radiograph from UGI shows the gastric pouch (P), Roux jejunal limb (J) and expected location of the left mid-abdominal jejunojejunal anastomosis (arrow). LPO, left posterior oblique; UGI, upper gastrointestinal.

Figure 3.

Expected anatomy following RYGB on CT. (a and b). Axial abdominal CT images acquired with both oral and i.v. contrast show a small gastric pouch (P), gastrojejunal anastomosis (arrowhead), Roux jejunal limb (arrow) and the excluded stomach (ES). Note the opacification of the alimentary jejunal limb (arrow) without opacification of the excluded stomach. RYGB, Roux-en-Y gastric bypass.

Figure 4.

Small leak following RYGB. Fluoroscopic UGI spot image in the LPO position shows the gastric pouch (P), gastrojejunal anastomosis (arrow) and Roux jejunal limb (J). There is extravasated contrast in the left of the anastomosis (arrowheads), consistent with a small extraluminal leak. Also noted extraluminal gas in the vicinity and an indwelling surgical drainage catheter. LPO, left posterior oblique; RYGB, Roux-en-Y gastric bypass; UGI, upper gastrointestinal.

Figure 5.

Staple line dehiscence following RYGB - communication with the excluded stomach. (a) UGI spot image in the supine position shows contrast opacifying the gastric pouch (P) and jejunal limb (J). There is also a collection of contrast to the left of the anastomosis (*). Contrast is seen more distally within the excluded stomach (ES) and duodenum (D). (b) With rotation of the patient into the RPO position, an opacified tract across the gastric staple line is noted (arrow) allowing for communication between the gastric pouch (P) and excluded stomach (ES). RYGB, Roux-en-Y gastric bypass; UGI, upper gastro intestinal; RPO, right posterior oblique.

Figure 6.

Gastrojejunal stomal narrowing following RYGB. Fluoroscopic UGI spot image acquired in the supine LPO position shows a dilated gastric pouch (P) with significant narrowing of the gastrojejunal anastomosis (arrow) due to post-operative edema. A small amount of contrast is noted opacifying the adjacent Roux jejunal limb (J). LPO, left posterior oblique; RYGB, Roux-en-Y gastric bypass; UGI, upper gastrointestinal.

Figure 7.

Small bowel obstruction of following RYGB with obstruction of the alimentary limb due to jejunojejunal stomal stenosis. (a and b) Axial and (c) coronal CT images following positive oral and i.v. contrast show marked dilatation of the gastric pouch (P) and Roux jejunal limb (A) (Alimentary limb) extending towards an abrupt transition at the jejunojejunal anastomosis (arrows) due to stomal stenosis and fibrosis. Distal small bowel is decompressed. The excluded stomach (S) is collapsed and is not opacified with luminal contrast. RYGB, Roux-en-Y gastric bypass.

Figure 8.

Small bowel obstruction following RYGB with obstruction of the excluded, biliopancreatic limb. (a and b). Axial CT images following positive oral and i.v. contrast show marked dilatation of the fluid-filled unopacified excluded stomach (ES), duodenum (D) and proximal jejunum (J) (biliopancreatic limb). The opacified alimentary Roux limb is not dilated (arrow). The RYGB anatomy and the jejunal limb must be recognized in order to make the appropriate diagnosis. Distal small bowel is also decompressed. Also note abdominal free fluid. RYGB, Roux-en-Y gastric bypass.

Figure 9.

Internal hernia following RYGB on UGI and CT (a). Supine UGI imaging shows an atypical bowel configuration following RYGB with clustered, displaced small bowel loops (arrows), high in the left upper quadrant, above the gastric pouch (P) and abutting the diaphragm. Small bowel can be seen entering and exiting the clustered segment (arrowhead). (b and c) Axial and (d) coronal CT images with oral and i.v. contrast show RYGB anatomy with clustered displaced small bowel loops high in the left upper quadrant (arrows) above the gastric pouch (P). The jejunojejunal anastomosis is also displaced cephalad (arrowhead) due to internal hernia. Mesenteric vessels are tethered superiorly. At surgery the patient was found to have a large transverse mesocolic internal hernia. RYGB, Roux-en-Y gastric bypass; UGI, upper gastrointestinal.

Figure 10.

LAGB diagram. Diagram depicts a silicone band (arrowhead) placed around the upper stomach to create a small gastric pouch (P) and a narrow stoma through the band to communicate with the remainder of the stomach. Tubing (arrow) connects the band to a reservoir along the abdominal wall (not shown). The band has an inner inflatable balloon cuff. LAGB, laparoscopic adjustable gastric banding.

Figure 11.

Expected appearance following LAGB on UGI (a) Supine radiograph shows the expected appearance following LAGB with a band in the left epigastric region (white arrow). Radio-opaque connecting tubing can be assessed as it extends to the injectable port (arrowhead). (b) Supine UGI image acquired while the patient is drinking shows a small pouch (P) with a narrow stoma (arrows) through the band and communicating with the gastric fundus (F). Note that in order to optimally asses the stoma the band must appear linear rather than as a ring shape. LAGB, laparoscopic adjustable gastric banding; UGI, upper gastrointestinal.

Figure 12.

Expected appearance following LAGB on CT (a) Coronal and (b) axial CT images with oral and i.v. contrast shows the inflatable balloon cuff of the band (white arrows) positioned around the proximal stomach. The connecting tubing is partially imaged (black arrow). LAGB, laparoscopic adjustable gastric banding.

Figure 13.

Concentric pouch dilatation following LAGB with a narrow stoma. UGI image acquired during drinking shows a concentrically dilated pouch (P) with a tight stoma (arrow) through the band. A small amount of contrast is seen in the gastric fundus (F). LAGB, laparoscopic adjustable gastric banding; UGI, upper gastrointestinal.

Figure 14.

Band slippage with fundic herniation following LAGB. (a) A supine radiograph shows a change in the configuration of the gastric band (arrow) as compared with a prior post-operative study (not shown). It is now inferiorly located and horizontal in configuration. (b) UGI image shows an eccentrically dilated gastric pouch (P) above the inferior, horizontal band (arrow) due to band slippage. A small amount of contrast is seen in the gastric fundus (F). LAGB, laparoscopic adjustable gastric banding; UGI, upper gastrointestinal.

Figure 15.

Band erosion following LAGB. UGI image following LAGB acquired with the patient drinking shows contrast extending superiorly and along the left aspect of the band (arrows), partially surrounding the band rather than opacifying a stoma through the band. The band is seen as a filling defect (arrowhead). This is due to intragastric erosion of the band. LAGB, laparoscopic adjustable gastric banding; UGI, upper gastrointestinal.

Figure 16.

SG diagram depicts the gastric sleeve (S) with approximately 70% of the stomach resected along the greater curvature of the stomach and with relative sparing of the antrum. Note the resection margin (arrows). The pylorus and duodenum are left intact. SG, sleeve gastrectomy.

Figure 17.

Expected appearance following SG on UGI. Supine UGI image show the narrowed, tubular configuration of the gastric sleeve (arrows) with an intact distal antrum (A), pylorus and duodenum (D). SG, sleeve gastrectomy; UGI, upper gastrointestinal.

Figure 18.

Expected appearance following sleeve gastrectomy on CT (a and b) axial and (c) coronal non-contrast CT images shows a narrowed stomach with suture along the resected greater curvature (arrows) and prominence of mesenteric fat in the expected location of the remainder of the stomach. Note the intact antrum (A).

Figure 19.

Small leak on UGI following SG. UGI image following SG shows a small amount of extravasated, extraluminal contrast (arrows) extending left laterally from the proximal gastric sleeve (S) in this recently post-operative patient. Also note extraluminal gas in the left upper quadrant (arrowheads). D, duodenum; SG, sleeve gastrectomy; UGI, upper gastrointestinal.

Figure 20.

Leak on CT following SG. (a) Axial and (b) coronal CT images following positive oral contrast administration show an ill-defined fluid collection (black arrows) and extraluminal gas (white arrows) in the left upper quadrant adjacent to the suture line (arrowhead) of the proximal gastric sleeve (S). The fluid collection is of subtle increased density anteriorly due to a small amount of extravasation administered oral contrast. D, duodenum; SG, sleeve gastrectomy.

Figure 21.

Leak on UGI following SG with endoscopic stent placement. UGI image following sleeve gastrectomy shows a stent placed in the distal esophagus and across the gastric sleeve (S). There is a persistent leak (arrows) from the proximal sleeve extending into the left upper quadrant despite stent placemen. A drainage catheter is coiled in the extraluminal collection (arrows). D, duodenum; SG, sleeve gastrectomy; UGI, upper gastrointestinal.

Figure 22.

Stricture and proximal pouch dilatation following SG. Supine UGI image following SG shows a focal stricture in the mid sleeve (arrow) with proximal dilatation of the sleeve (S). SG, sleeve gastrectomy; UGI, upper gastrointestinal.