Gallbladder Hydrops: Definition and Clinical Significance
Gallbladder (GB) hydrops is a pathologic condition characterized by marked distention of the gallbladder with clear, acalculous fluid ("white bile") in the absence of bacterial infection, typically caused by cystic duct obstruction. 1
Pathophysiology
Hydrops develops when the cystic duct becomes obstructed (most commonly by a stone lodged in the gallbladder neck or cystic duct), leading to bile stasis and subsequent mucosal changes 2
The gallbladder fills with clear, viscous "white bile" that is sterile in nearly all cases, with dramatically reduced concentrations of bilirubin, bile salts, cholesterol, phospholipids, and proteins (often <1 mg%) 2
Intraluminal pressure increases significantly (averaging 61.5 cm saline, ranging from 15-115 cm), while the bile remains roughly isotonic with blood (approximately 295 mosmol/kg) 2
Mucosal inflammation following obstruction disrupts normal reabsorptive processes and triggers mucous secretion, contributing to the progressive distention 2
Clinical Presentation
In Adults
Gross increases in transverse diameter or overall gallbladder size on ultrasound may indicate hydrops, particularly in the context of cholecystitis 1
Hydrops in adults is almost always associated with cholelithiasis (stone obstruction), occurring in approximately 5.4% of cholecystectomy cases (40 of 739 cases in one series) 2
In Children
Acute hydrops in children presents distinctly with abdominal pain, vomiting, palpable abdominal mass, and tenderness that can mimic acute appendicitis, intussusception, or volvulus 3, 4
Pediatric hydrops occurs WITHOUT stones, bacteria, or congenital malformations, distinguishing it from adult disease 3
Kawasaki disease is a major cause of gallbladder hydrops in children, representing a significant component of the abdominal crisis in this syndrome 5, 6
Diagnostic Approach
Ultrasound is the diagnostic modality of choice, demonstrating a markedly distended gallbladder with normal biliary ducts, absence of calculi (in pediatric cases), and no congenital malformations 4, 6
Key sonographic features include: increased transverse GB diameter (>5 cm suggests pathology), wall thickening (>3 mm is abnormal), and assessment for pericholecystic fluid 1
In children with hydrops, actively look for Kawasaki disease features including prolonged fever, rash, conjunctivitis, oral changes, and lymphadenopathy to avoid unnecessary surgery 5, 6
Management Considerations
Pediatric Hydrops
Nonoperative management with serial ultrasound monitoring is safe and effective for pediatric hydrops, particularly when associated with Kawasaki syndrome 5
Surgical intervention should be reserved only for complications such as perforation or gangrene; simple cholecystostomy (not cholecystectomy) is sufficient if surgery becomes necessary 6
Adult Hydrops
- Cholecystectomy is typically required since adult hydrops is almost always due to stone obstruction of the cystic duct 2
Critical Pitfalls
Do not mistake pediatric hydrops for acute appendicitis or other surgical emergencies—ultrasound can prevent unnecessary laparotomy 3, 4
In children with abdominal symptoms and fever, consider Kawasaki disease before proceeding to surgery, as medical management is preferred 5, 6
Hydrops does not exclude other life-threatening conditions such as aortic aneurysm or myocardial infarction in adults presenting with right upper quadrant pain 7