Biliary Dyskinesia / Chronic Acalculous Cholecystitis
Overview: Biliary dyskinesia, also known as chronic
acalculous cholecystitis, is a functional gallbladder disorder
characterized by abnormal contractility and low ejection fraction
on HIDA scan, often presenting with chronic right upper quadrant
pain despite normal imaging and labs.
I. Definition
Biliary dyskinesia is a functional disorder of
the gallbladder characterized by:
- Abnormal gallbladder contractility
- Low ejection fraction (EF) on HIDA scan after stimulation
- Absence of gallstones or structural abnormalities
It is also referred to as chronic acalculous
cholecystitis when histologic inflammation is
present. The condition is common in pediatric populations and is
one of the leading indications for cholecystectomy in children
and adolescents.
II. Clinical Features
- Chronic right upper quadrant (RUQ) abdominal pain
- Pain triggered by fatty food intake
- Normal gallbladder imaging (no stones, normal wall
thickness)
- Normal liver function tests
III. Histology
Histologic examination of resected gallbladders shows chronic
inflammatory changes in 50%–93% of cases,
supporting the diagnosis even when imaging is normal.
IV. Diagnosis
- HIDA scan with stimulation (cholecystokinin
[CCK] or fatty meal)
- Gallbladder EF is calculated as:
- (Tracer before stimulation − Tracer after stimulation) ÷
Tracer before stimulation
- In adults, EF < 35% is considered abnormal
- Pediatric norms are not standardized, but EF < 15%
correlates with symptom resolution post-cholecystectomy
- Protocols for timing of poststimulation measurement vary and
are not universally established