Bariatric surgery complications

Background

• Rou-en-Y - malabsorptive and restrictive physiology 
• Gastric Sleeve - restrictive
• Biliopancreatic diversion
• Vertical banded gastroplaty - now historical as replaced by LAP band 
• Lap Band Complications

Clinical Features

• abdominal pain, food intolerance
• sepsis, abnormal VS

Differential Diagnosis

Early

• VTE, PNA, UTI, SBO, etc
• Roux-Limb Obstruction
  • NV, abd pain
  • causes acute Gastric dilation
  • surgical emergency
  • IR decompression possible
• Anastamotic Leak
  • abdominal exam often non-acute due to habitus
• Intra-abdominal bleeding
  • may bleed into GI tract and only visualized on endoscopy

Late

• UGIB
  • resuscitate in stanrd fashion
  • emergent endoscopy
  • often bleed from staple lines, ulcers
• Anastomotic Leak or Stricture
  • progressive inability to tolerate PO
  • abdominal pain
  • solids first then liquids
  • needs UGI then likely endoscopy
• Marginal Ulcer
  • epigastric pain and dyspepsia
  • upper endoscopy
  • manage with acid suppression
• Internal hernia
  • obstructive or nonobstructive
  • crampy intermitten abd pain radiating to back
  • can have nl abd exam
  • may strangulate herniated bowel
  • w/u CT AP and UGI
  • CT findings swirl sign, intussuscepted bowel
  • needs surgery early
• Nurtitional Complications
  • consider patients immunosuppressed due to malnourishment
  • Anemia, neuropathy, fractures, hypercalcemia
  • Wernickes encephalopathy
  • Dumping syndrome

Diagnosis

• CT AP - use PO & IV contrast
  • pts often cannot tolerated full 1L of PO contrast
  • sip as much contrast as possible in 3hrs then CT    
  • weight limit of CT scanner often exceeded
  • can use Gastrograffin UGI series instead
• UGI series
  • beware GI pouch limits on contrast volume
  • usefull for perforation, internal hernia, stricture, leak

Specific Surgeries

Roux-en-Y gastric bypass

• Creation of a small gastric pouch and an anastomosis to the jejunum
• Gastric remnant distension
  • Remnant is a blind pouch that may become distended with paralytic ileus
  • Potential rupture → severe peritonitis
  • 3.9% leak rate for RYGB; overall mortality 0.6%
  • Jejunojejunostomy leak a/w 40% mortality
  • S/s: pain, hiccups, LUQ tympany, shoulder pain, abd distention
  • Dx: XR shows large gastric air bubble vs CT
  • Tx: emergent operative decompression with percutaneous drainage
• Stomal Stenosis
  • Occurs in 6-20% of RYGB patients
  • Possibly related to tissue ischemia or tension on GJ anastomosis
  • Presentation several weeks after surgery
  • S/s: N/V, dysphagia, GERD, inability to tolerate PO
  • Dx with endoscopy vs UGI series vs CT
• Marginal Ulcers
  • Occur in 0.6-16% of RYGB patients
  • Acid injury to jejunum
  • Causes: poor perfusion 2/2 tension/ischemia, increase gastric acid exposure, NSAID use, H pylori infection
  • S/s: Nausea, pain, bleeding +/- perforation
  • Dx with endoscopy
  • Patients typically medically managed
• Cholelithiasis
  • 38% of RYGB patients
    • Risk reduced to 2% if ursodiol given as post-op ppx
    • Some surgeons perform prophylactic cholecystectomy with RYB procedure
  • Rapid weight loss increases lithogenicity of bile
  • Dx: U/S or MRCP
• Hernias
  • Ventral hernias (0-1.8% in lap RYGB)
  • Internal hernias (0-5%)
    • Intermittent and may be difficult to detect via CT
    • Suspected may require urgent surgical exploration lest patient has strangulated pathology
• Dumping Syndrome
  • Occur in up to 50% of patients when high levels of carbohydrates are ingested
  • Early dumping syndrome
    • Occurs when pylorus is either removed or bypassed, allowing hyperosmolar stomach chyme to "dump" into the small intestine.
    • Hyperosmolality of food → fluid shifts into GI lumen → colicky and pain, diarrhea, nausea, tachycardia, diaphoresis, dizziness, syncope.
    • Tx: Diet modification to avoid high simple sugars
  • Late dumping syndrome
    • Insulin response that leads to hypoglycemia 2-3 hours after meal
    • S/s: dizziness, fatigue, diaphoresis, weakness

Gastric Banding

• Placement of restrictive ring over the gastric cardia near the GE junction
• Lowest mortality rate among all bariatric surgeries (0.05% mortality)
• Stomal Obstruction
  • Early complication; occurs in 14% go GB patients
  • Typically 2/2 inclusion over excess perigastric fat vs tissue edema vs inappropriate sized band
  • S/s: N/V, inability to tolerate PO
  • Dx: UGI series vs CT
  • If due to edema, may be treated with NG tube decompression until swelling improves
    • May require surgical revision if above unsuccessful
• Port infection
  • 0.3-9% of GB patients
  • a/w band erosion
  • Tx: Replacement of port if isolated infection vs band if more extensive
• Band Erosion
  • Up to 7% of GB patients
  • Erodes through gastric wall 2/2 wall ischemia vs mechanical stress from band
  • Occurs on average 22 months after surgery
  • S/s: e/o infection, failure to lose weight, N/V; epigastric pain and hematemesis
  • Dx: Endoscopy vs CT
  • Tx: Band removal
• Band Slippage/gastric prolapse
  • 2-14% of patients
  • Either anterior or posterior prolapse
  • S/s: Food intolerance, epigastric pain, acid reflux
  • Dx: Upper GI series vs CT
  • Tx: Emergent surgery
• Esophageal dilatation
  • Up to 10% of patients
  • a/w over-inflated bands or excessive food intake
  • S/s: Food/saliva intolerance, reflux, epigastric pain
  • Dx: UGI series vs CT
  • Tx: Fluid removal from band initially and behavioral modifications
• Hiatus hernia
  • Results in refractory reflux

Sleeve gastrectomy

• Creates sleeve out of the stomach and removes portion of greater curvature of stomach
• Complication rate 3-24%; mortality 0.39%
• Bleeding
  • Typically occur from the staple line
• Stenosis
  • Can lead to gastric outlet obstruction
  • S/s: Dysphagia, vomiting, dehydration, inability to tolerate PO
  • Dx: UGI series vs CT
  • Tx: Endoscopic dilatation vs surgical intervention depending on involvement
• Gastric leaks
  • Up to 5.3% of patients; most serious complication a/w sleeve gastrectomy
  • 2/2 poor healing in setting of inadequate blood supply vs weakness at staple line vs gastric-wall heat ischemia from cautery
  • Tx: surgical repair vs percutaneous drainge/abx/NPO
• Reflux
  • Common post-op complication
  • Treated medically initially with eventual RYGB for refractory cases

See Also

• Lap Band Complications

References

1. Tack, Jan, et al. “Complications of bariatric surgery: Dumping syndrome, reflux and vitamin deficiencies.” Best practice and research clinical gastroenterology; 28; 2014; pages 741-749.