What is gallbladder hydrops?

Gallbladder Hydrops: Definition and Clinical Significance

Gallbladder hydrops is a condition characterized by marked distension of the gallbladder with non-inflammatory fluid, typically resulting from obstruction of the cystic duct or gallbladder neck, most commonly by gallstones. 1

Pathophysiology

Gallbladder hydrops develops through the following mechanism:

• Obstruction of bile flow (typically at the gallbladder neck or cystic duct)
• Mucosal inflammation following obstruction
• Disturbances in reabsorptive processes
• Secretion of mucus
• Subsequent increase in intraluminal pressure 2
• Accumulation of clear, sterile "white bile" that is typically very viscous 2

The intraluminal pressure in hydrops can be significantly elevated, averaging 61.5 cm saline (range 15-115 cm) 2. The fluid is generally isotonic with blood, with an average osmolality of 295 mosmol/kg 2.

Diagnostic Features

Gallbladder hydrops is identified by the following sonographic characteristics:

• Markedly distended gallbladder
• Increased transverse diameter (>5 cm) 1
• Absence of gallstones within the lumen (acalculous) in some cases, though often caused by a stone in the gallbladder neck or cystic duct 2
• Clear fluid content ("white bile") 2
• Normal biliary ducts 3

Etiologies

Gallbladder hydrops can occur in various clinical scenarios:

1. Obstructive: Most commonly due to gallstones lodged in the gallbladder neck or cystic duct 2
2. Associated with systemic conditions:
   • Kawasaki disease (particularly in children) 4, 5
   • Other pediatric illnesses 3
3. Idiopathic: Particularly in children, where the etiology may be multifactorial 3

Clinical Presentation

Patients with gallbladder hydrops typically present with:

• Right upper quadrant pain (often severe) 6
• Nausea and vomiting
• Abdominal mass and/or tenderness 3
• Fever (particularly when associated with conditions like Kawasaki disease) 4
• Jaundice (in some cases) 4

The presentation may mimic other acute abdominal conditions such as acute cholecystitis, acute appendicitis, intussusception, or volvulus 3.

Diagnostic Approach

Ultrasound is the primary diagnostic tool for gallbladder hydrops:

• Transabdominal ultrasound should be performed to assess gallbladder size, wall thickness, and presence of obstructing lesions 1, 7
• The gallbladder should be systematically scanned in both long and short axis views 1
• Particular attention should be paid to the gallbladder neck to identify potential obstructing lesions 1

If ultrasound findings are equivocal:

• Consider contrast-enhanced ultrasound (CEUS) or MRI for further characterization 7

Management

Treatment approach depends on the underlying cause, severity, and associated conditions:

Non-surgical Management

• Appropriate for uncomplicated cases, particularly in children with Kawasaki-associated hydrops 5
• Serial ultrasound evaluation and close clinical monitoring 5
• Supportive care until resolution 4

Surgical Management

• Indicated for:
  • Persistent symptoms despite medical management
  • Complications such as perforation or infection
  • Cases where malignancy cannot be excluded
• Laparoscopic cholecystectomy is the preferred approach for most patients 7
• Simple cholecystostomy may be sufficient in high-risk patients or as a temporizing measure 4

Special Considerations

Pediatric Patients

• Hydrops in children is often associated with Kawasaki disease 4, 5
• Non-operative management with close monitoring is generally preferred 5
• Surgical intervention should be reserved for complications 4

Mimics of Acute Abdomen

• Gallbladder hydrops can present with signs of peritonitis, mimicking acute surgical conditions 4
• Ultrasonography is crucial to establish the correct diagnosis and avoid unnecessary surgery 4

Pitfalls and Caveats

• Gallbladder hydrops can be mistaken for acute cholecystitis, leading to premature surgical intervention
• In Kawasaki disease, abdominal symptoms may precede the full clinical manifestation of the disease, making diagnosis challenging 4
• The preferred treatment for hydrops in Kawasaki disease is medical, with surgery reserved only for complications 4
• Gallbladder hydrops should be distinguished from tumefactive sludge, which can have a similar appearance on imaging 1

By understanding the pathophysiology, clinical presentation, and appropriate management of gallbladder hydrops, clinicians can provide timely and appropriate care while avoiding unnecessary interventions.