What does a gallbladder ejection fraction (GBEF) over 80% indicate?

Gallbladder Ejection Fraction Over 80%: Clinical Significance and Management

A gallbladder ejection fraction (GBEF) over 80% may indicate biliary hyperkinesia, a controversial type of functional gallbladder disorder that can cause biliary symptoms and may benefit from cholecystectomy in selected patients. 1

Understanding Gallbladder Ejection Fraction

• Normal GBEF is defined as ≥38% when measured using the standardized cholecystokinin-cholescintigraphy (CCK-CS) protocol with infusion of 0.02 μg/kg sincalide over 60 minutes. 2
• The upper limit of normal GBEF approaches 100%, and historically there was no convincing evidence that a high normal GBEF was of clinical significance. 2
• However, recent research suggests that an EF cutoff of 81% can be considered a reasonable upper limit of normal gallbladder function. 1

Clinical Significance of Elevated GBEF (>80%)

• GBEF >80% may represent biliary hyperkinesia, a condition where the gallbladder contracts too forcefully or rapidly. 1
• Patients with biliary hyperkinesia typically present with biliary-type pain despite having no evidence of gallstones on ultrasound. 3, 1
• Recent research found that patients with biliary symptoms and GBEF ≥81% had better pain resolution after cholecystectomy (78.2%) compared to those with GBEF <81% (60.0%, p=0.03). 1

Diagnostic Considerations

• CCK-CS is the standard test for assessing gallbladder contraction and calculating GBEF. 2
• Standardized methodology is critical for reliable GBEF measurement:
  • Infusion of 0.02 μg/kg sincalide over 60 minutes (not rapid infusion) 2
  • Dynamic imaging (1 image per minute) during infusion 2
  • GBEF calculation at 60 minutes 2
• Symptom provocation during CCK infusion is not a reliable diagnostic indicator of gallbladder disease. 2

Management Approach for Elevated GBEF

• For patients with typical biliary symptoms and GBEF >80% but no evidence of gallstones:
  • Consider diagnosis of biliary hyperkinesia 1
  • Cholecystectomy may be beneficial, with studies showing pain resolution in approximately 78% of patients 1
• Before proceeding with surgery, rule out other causes of upper abdominal pain:
  • Functional gastrointestinal disorders 4
  • Sphincter of Oddi dysfunction 4, 3
  • Gastroesophageal reflux disease 4
  • Peptic ulcer disease 4

Pathophysiology and Outcomes

• Chronic cholecystitis was found in 61.7% of patients with elevated GBEF who underwent cholecystectomy in recent studies. 1
• The mechanism of biliary hyperkinesia is not fully understood but may involve abnormal gallbladder contractility or sensitivity to CCK. 3, 1
• Long-term studies show that GBEF values tend to be reproducible over time in patients without intervention. 5

Important Caveats

• The concept of biliary hyperkinesia remains somewhat controversial, with limited high-quality evidence. 1
• Patient selection is critical - best results occur in those with typical biliary colic symptoms. 6
• Avoid rapid CCK infusion (<30 minutes), as this can cause non-specific abdominal symptoms that confound interpretation. 2
• Ensure proper standardized protocol is used for CCK-CS to obtain reliable GBEF measurements. 2

Clinical Decision Algorithm

1. Confirm GBEF >80% using standardized 60-minute CCK infusion protocol 2
2. Verify presence of typical biliary symptoms (episodic right upper quadrant or epigastric pain) 3, 6
3. Rule out gallstones and other biliary pathology with ultrasound 7, 1
4. Exclude other common causes of upper abdominal pain 4
5. Consider cholecystectomy if GBEF ≥81% with typical biliary symptoms 1
6. Monitor for symptom resolution post-cholecystectomy 1, 6