see also:

• obesity and weight management
• the patient with acute abdominal pain in the ED

• many patients now present to EDs who have lap bands in situ and present with abdominal pain or vomiting and the question raised is could it be a complication of the lap band such as lap band slippage, band erosion or stomal obstruction.

• lap band slippage
  • generally present with acute severe upper abdominal or chest pain, complete inability to tolerate saliva or oral liquids, and repetitive vomiting
  • Dx:
    • plain erect abdominal X-ray or water-soluble swallow study fluoroscopy showing an abnormal band angle (φ angle outside the normal 4–58° range) or an enlarged gastric pouch
• stomal obstruction / food bolus
  • generally presents with inability to keep down liquids, “sliming” (excessive mucous regurgitation), and sharp epigastric pain
  • this is caused by poorly chewed food or excessive tightening/overfilling of the band
• band erosion or migration
  • may present with vague, persistent epigastric pain, loss of weight-loss restriction, or localized port-site infection/redness
  • Dx:
    • upper endoscopy (EGD) or CT scan showing the band inside the gastric lumen
• non-band complications
  • rapid weight loss from bariatric surgery increases the risk of symptomatic gallstones or biliary colic presenting as right upper quadrant pain

• staple line leak
  • most common in the early postoperative weeks
  • presents with tachycardia, fever, left shoulder pain, and worsening abdominal pain
• stricture / kinking
  • narrowing of the remaining sleeve (often at the incisura angularis)
  • causes progressive, chronic vomiting of food and liquids weeks to months after surgery
• severe gastro-oesophageal reflux
  • very common long-term complication and risks oesophageal cancer
  • whilst gastric acid secretion is reduced due to loss of parietal cells, a gastric sleeve creates a high-pressure system while simultaneously weakening the anatomy designed to prevent backflow
    • the surgery transforms a large, highly distensible stomach pouch into a long, narrow, rigid tube with a capacity of only about 150 mL
    • the fundus (the top, stretchy part of the stomach) is entirely removed - without this reservoir to accommodate meals or normal secretions, eating or drinking causes an immediate, sharp spike in pressure inside the new sleeve. This high pressure easily forces fluids upward into the oesophagus as it is within a low-pressure chest cavity
    • normally, the oesophagus enters the stomach at a sharp, acute angle known as the Angle of His. This angle acts as a flap-valve: when the stomach fills, it presses against the esophagus to seal it shut. Creating a straight sleeve obliterates this acute angle, removing a major natural flap-valve mechanism.
    • the surgical dissection and stapling close to the gastro-oesophageal junction frequently sever the “sling fibres” of the stomach. These muscle fibres are vital for reinforcing the lower oesophageal sphincter (LOS). Without them, the resting pressure of the LOS drops, leaving a weaker valve.
    • as the volume of fluid required to trigger reflux is much lower, what little acid is produced still ends up in the oesophagus and more importantly, the reflux fluid is frequently a mixture of digestive enzymes, pepsin, and highly alkaline bile traveling up from the small intestine. Bile reflux can irritate and inflame the oesophageal lining just as severely as pure hydrochloric acid, causing classic heartburn and GORD symptoms
• vitamin B12 (cobalamin) deficiency
  • the area removed contains the majority of the stomach's parietal cells, which produce intrinsic factor — a protein absolutely mandatory for binding and absorbing vitamin B12 later in the small intestine
  • parietal cells also produce hydrochloric acid (stomach acid). Stomach acid is required to chemically detach vitamin B12 from the food proteins you eat. Without enough acid, the B12 remains locked in the food and cannot be processed.

• clinical history and examination, specifically looking for evidence of complications or other pathology
• usual blood tests for acute abdo pain - see the patient with acute abdominal pain in the ED
• imaging as indicated
• IV fluids if dehydrated
• refer to surgical team if lap band or gastric sleeve complication is suspected
  • if acute obstruction or a severe slip of a band is suspected, consider decompression of the band
    • locate the subcutaneous port and use a non-coring Huber needle to aspirate all saline