Restricting Appetites: Common and Unusual Post-operative Complications for Gastric Bands S Tincey1, A Hadjivassiliou1, A Tavare1, P Sufi2, M Steward1 Department of Radiology1 and Bariatric & Upper GI Surgery2, Whittington Hospital, London

Background Obesity has become an epidemic in the western world and is associated with high morbidity and mortality (1). Obesity is defined with the Body Mass Index (BMI) as follows: Overweight BMI 25-29 kg/m2 Obesity BMI 30 - 35 kg/m2 Morbid obesity BMI >35 – 40 kg/m2

Background Treatment options for obesity include behavioural, medical and surgical Surgery provides the most reliable longterm solution Laparoscopic gastric band insertion is commonly performed for the management of morbid obesity (4)

Procedure Gastric banding works by promoting early satiety leading to reduced oral intake and subsequent weight loss (2) An adjustable silicon band is used. This is placed approximately 2 cm distal to the gastro-oesophageal junction The stomach is subsequently divided into two pouches The proximal pouch is smaller ~15-20 mls Band paper 1

Procedure The stoma of the band should be ~3-4 mm in width to allow emptying of gastric pouch contents in 15 – 20 minutes Stitches are placed on the gastric serosa joining the anterior portion of the distal stomach with the small proximal pouch to minimise risk of slippage The band is then connected with an anterior abdominal wall implantable port via a tube Band paper 1

Procedure The port is used to adjust the stoma of the gastric band by either inserting or removing saline. This is performed under fluoroscopic guidance Adjustment of the band is guided by the patient’s weight loss and symptoms

Normal band position The band is positioned within the proximal stomach approximately 2 cm from the gastro-oesophageal junction The band should have an oblique orientation (~45 degrees) with its lateral aspect lying more superiorly than its medial aspect (WHL 181)

Normal band position ~45° Figure 1: Normal band position and orientation (red arrow) as seen on fluoroscopy (a). Oral contrast is seen to pass freely beyond the band with normal stomal width (orange arrow) and no upstream oesophageal dilatation (b).

Normal band position Figure 2: Contrast enhanced coronal MDCT showing radio-opaque band in its normal position (red arrows).

Complications Common Uncommon Alternatively complications can be classified as early and late complications

Complications Table 1: Complications of gastric band surgery (3)

Complications Common: Slippage Port breakage Infection

Slippage Slippage implies herniation of gastric parts through the band. There are different types: Anterior Occurs in patients with gastroesophageal band and weakened stabilising sutures. The band rotates clockwise Posterior Occurs in patients with retrogastric band placement (no longer performed). The band is displaced in a counter clockwise direction Band paper 1

Slippage Figure 3: Patient presented with vomiting and intolerance of solids and liquids. Abnormally positioned gastric band (red arrow) lying horizontally (180 °) was identified on fluoroscopy. No contrast is seen distal to the band. Note the overhanging edge of the stomach (blue arrow). This patient went on to have band deflation under fluoroscopic guidance and surgical referral.

Slippage Figure 4: A slipped horizontal gastric band (red arrow) on fluoroscopy. Note that in this patient the distal stomach is opacified (green arrow) illustrating that there is still passage of contrast distal to the band.

Slippage and Stricture IS THIS IMAGE LABELLED CORRECTLY? WHERE IS THE STRICTURE?? Figure 5: Fluoroscopy image of patient with slipped band (band not present on this image) which was subsequently removed but had stricture formation at the site of chronically slipped band (red arrow).

Slippage Figure 6: Patient with a slipped band on post contrast enhanced MDCT. Note the abnormal band orientation (red arrow) where the lateral edge is inferior to the medial portion. Note the proximal stomach dilatation with overhanging edges of the stomach (yellow arrow).

Slippage Figure 7: Fluoroscopy image of horizontally lying band (red arrow) and secondary oesophageal dilatation (blue arrows).

Oesophageal dilatation Figure 8: Patient with oesophageal dilatation (green arrow). Tertiary contractions (orange arrows) were also seen in keeping with oesophageal dysmotility. Gastric band (red arrow).

Oesophageal dilatation intervention Figure 9: Patient with previously demonstrated oesophageal dilatation on fluoroscopy. The band (red arrow) was deflated via aspiration. This is done by puncturing the port (blue arrow) with a needle (green arrow) under fluoroscopic guidance.

Infection Figure 10: Patient presented with sepsis. Contrast enhanced coronal MDCT shows evidence of low attenuation and fat stranding (blue arrow) around the port site in keeping with infection.

Complications Uncommon: Erosion Tube kink Stricture

Band Erosion Figure 11: Post contrast enhanced coronal MDCT. Intramural gas locules (green arrow) indicating microperforation at an early stage in the development of erosion. These findings are in keeping with the band (red arrow) eroding into the gastric lumen, confirmed at endoscopy.

Tubing Erosion Bladder Figure 12: Coronal MDCT shows tubing seen to be abnormally straightened, extending into the pelvis (red arrow) and eroding through the bladder wall (yellow arrow).

Tube Kink Figure 13: Fluoroscopy image: Kink demonstrated within the tubing (orange arrow) connecting the gastric band (not included in this image) to the anterior abdominal wall implantable port (green arrow). The band was unable to be filled and tubing required surgical manipulation.

Conclusion Obesity is associated with high morbidity and mortality Laparoscopic gastric band insertion is a minimally invasive procedure performed to promote weight loss There are common and uncommon complications of gastric bands Identifying these on imaging is crucial for patient management

References Imaging of bariatric surgery: normal anatomy and postoperative complications. Levine M, Carucci R. Radiology. 2014 Feb;270(2):327-41 Radiographic imaging of the normal anatomy and complications after gastric banding. H Prosch, R Tscherney, S Kriwanek, D Tscholakoff. Br J Radiol. 2008 Sep;81(969):753-7. Complications associated with adjustable gastric banding for morbid obesity: a surgeon’s guide. Eid I, Birch, D, Sharma A, Sherman, V, Karmali S. Can J Surg. Feb 2011; 54(1): 61–66. Laparoscopic adjustable gastric banding: What radiologists need to know. Sonavane et al. Radiographics July – August 2012 , Volume 32, Issue 4