Overview
Definition:
A choledochal cyst is a congenital cystic dilatation of the bile ducts, most commonly affecting the common bile duct, but can involve intrahepatic ducts
Intrahepatic stones (choledocholithiasis) within these dilated intrahepatic ducts are a frequent and significant complication, presenting a diagnostic and management challenge.
Epidemiology:
Rare congenital anomaly, with an estimated incidence of 1 in 100,000 to 1 in 150,000 live births
More common in East Asian populations, particularly females (4:1 ratio)
Presentation can occur at any age, from infancy to adulthood, but the pediatric form is most concerning due to early complications.
Clinical Significance:
Pediatric choledochal cysts with intrahepatic stones pose a significant risk of recurrent cholangitis, pancreatitis, hepatic abscess, portal hypertension, and ultimately, malignant transformation (cholangiocarcinoma), even in children
Early diagnosis and definitive surgical management are crucial for preventing these severe sequelae and improving long-term outcomes.
Clinical Presentation
Symptoms:
The classic triad of pain, jaundice, and an abdominal mass is present in less than 20% of pediatric patients
More common presentations include: Intermittent or persistent abdominal pain, typically in the right upper quadrant
Recurrent episodes of fever and chills, suggestive of cholangitis
Jaundice, which may be intermittent or progressive
Nausea and vomiting
Poor feeding or failure to thrive in infants
Clay-colored stools and dark urine
Palpable abdominal mass (less common).
Signs:
Right upper quadrant tenderness or a palpable mass
Hepatosplenomegaly may be present
Signs of dehydration and sepsis in cases of severe cholangitis
Icterus of sclera and skin
Ascites (rare, typically in advanced disease).
Diagnostic Criteria:
No single definitive diagnostic criterion exists, but a combination of clinical suspicion, biochemical markers, and characteristic imaging findings leads to diagnosis
Todani's classification system (Type I-V) is widely used to categorize choledochal cysts based on location and extent
The presence of stones within the dilated intrahepatic ducts further guides management.
Diagnostic Approach
History Taking:
Focus on duration and nature of abdominal pain, pattern of fever and jaundice, history of recurrent infections, and any previous investigations
Ask about family history of biliary anomalies
Screen for red flags: high fever, severe pain, altered consciousness, hematemesis, or melena, indicating complications like sepsis or bleeding.
Physical Examination:
Thorough abdominal examination for tenderness, guarding, rebound tenderness, and organomegaly
Assess for icterus and signs of dehydration
Cardiovascular and respiratory systems should be evaluated for signs of sepsis.
Investigations:
Liver function tests (LFTs): Elevated total and direct bilirubin, alkaline phosphatase, and GGT
AST and ALT may be mildly elevated
White blood cell count is often elevated during cholangitis
Imaging: Ultrasound is the initial modality of choice, showing cystic dilatation of the bile duct, gallstones, and intrahepatic ductal dilatation
Magnetic Resonance Cholangiopancreatography (MRCP) is the gold standard for delineating the anatomy, extent of the cyst, and presence/location of stones
Endoscopic Retrograde Cholangiopancreatography (ERCP) is both diagnostic and therapeutic, allowing for stone extraction and stent placement, but carries higher risks in pediatric patients than MRCP
CT scan can be helpful in evaluating associated abnormalities or complications like abscesses.
Differential Diagnosis:
Other causes of pediatric abdominal pain and jaundice, including: Biliary atresia (different pathology, but can coexist or be mistaken initially)
Viral hepatitis
Kasai procedure failure
Gallstones (unusual in pediatric population without risk factors, but possible)
Pancreatitis
Appendicitis
Intussusception
Ovarian/testicular torsion (in older children).
Management
Initial Management:
For symptomatic patients with cholangitis: intravenous antibiotics (e.g., piperacillin-tazobactam or ceftriaxone with metronidazole) to cover gram-negative and anaerobic organisms
Fluid resuscitation and electrolyte correction
Analgesia
Nutritional support.
Medical Management:
Primarily supportive and aimed at managing acute complications like cholangitis
Long-term medical management is not curative
surgical intervention is essential.
Surgical Management:
The cornerstone of treatment
Complete excision of the extrahepatic bile duct cyst (if present) with a wide Roux-en-Y hepaticojejunostomy is the standard procedure
Intrahepatic stones are removed during surgery
Indications for surgery include: Symptomatic cysts (pain, jaundice, cholangitis)
Asymptomatic cysts with risk of complications
All choledochal cysts, especially Type I and IV
For Type III cysts (intraduodenal), endoscopic management may be considered initially
Radical excision of the cyst and reconstruction with a hepaticojejunostomy prevents stasis, bile duct cancer, and cholangitis.
Supportive Care:
Postoperative care includes pain management, intravenous fluids, nutritional support (often with parenteral nutrition initially), and monitoring for complications
Antibiotics may be continued postoperatively if indicated
Monitoring of LFTs and urine output is essential.
Complications
Early Complications:
Bleeding from the operative site
Bile leak from the hepaticojejunostomy
Cholangitis and sepsis
Pancreatitis
Anastomotic stricture
Wound infection.
Late Complications:
Intrahepatic ductal stones (recurrent choledocholithiasis)
Cholangiocarcinoma (lifetime risk is significant, up to 10-15% in some series)
Portal hypertension due to biliary cirrhosis
Stricture of the hepaticojejunostomy leading to secondary biliary cirrhosis
Malabsorption and nutritional deficiencies.
Prevention Strategies:
Complete and adequate excision of the cyst wall
Tension-free hepaticojejunostomy
Prompt diagnosis and surgical management
Aggressive treatment of cholangitis
Long-term surveillance for malignancy and complications.
Prognosis
Factors Affecting Prognosis:
Age at diagnosis and treatment
Extent and type of cyst
Presence and management of intrahepatic stones
Development of complications such as cholangiocarcinoma or biliary cirrhosis
Quality of surgical reconstruction.
Outcomes:
With timely and complete surgical treatment, the prognosis is generally good, with most children leading normal lives
However, the risk of cholangiocarcinoma persists throughout life, necessitating lifelong follow-up
Recurrence of stones and cholangitis can occur if management is incomplete.
Follow Up:
Lifelong follow-up is recommended for all patients treated for choledochal cysts
This includes annual clinical assessment and LFTs
Periodic imaging (ultrasound or MRCP) may be performed to screen for recurrent stones, strictures, or signs of malignancy
Patients should be educated about the risk of cholangiocarcinoma and report any new or worsening symptoms promptly.
Key Points
Exam Focus:
Remember Todani classification and its management implications
Recognize that intrahepatic stones are a common complication and influence surgical strategy
Emphasize the lifelong risk of cholangiocarcinoma and the need for surveillance
Surgical technique of complete excision and Roux-en-Y hepaticojejunostomy is paramount.
Clinical Pearls:
The "classic triad" is rarely seen in pediatric patients
suspect choledochal cyst in children with recurrent unexplained abdominal pain, fever, and jaundice
MRCP is crucial for detailed anatomical assessment and planning
Aggressive antibiotic management for cholangitis is vital
Never underestimate the risk of malignancy, even in young patients.
Common Mistakes:
Incomplete excision of the cyst wall, leading to recurrence or malignancy
Failure to adequately remove all intrahepatic stones
Inadequate surgical reconstruction of the biliary-enteric anastomosis
Delayed diagnosis and management, leading to irreversible liver damage or malignancy
Underestimating the risk of cholangiocarcinoma in follow-up.