Overview
Definition:
Common Bile Duct (CBD) exploration is a surgical procedure to directly visualize, identify, and remove stones, strictures, or other pathology from the CBD
Transcystic exploration involves accessing the CBD through the cystic duct, typically performed laparoscopically or during open cholecystectomy.
Epidemiology:
Choledocholithiasis, the presence of stones in the CBD, occurs in 5-15% of patients undergoing cholecystectomy
Transcystic exploration is favored in select cases, especially when there is a low perceived burden of CBD stones.
Clinical Significance:
Undiagnosed or undertreated CBD stones can lead to serious complications such as cholangitis, pancreatitis, biliary cirrhosis, and sepsis
Accurate and complete stone clearance is crucial for patient outcomes and preventing recurrent disease.
Indications
Indications For Exploration:
Presence of CBD stones confirmed on imaging (ERCP, MRCP, intraoperative cholangiogram)
Symptomatic choledocholithiasis
Suspected retained CBD stones post-cholecystectomy.
Selection Criteria For Transcystic:
Small to moderate-sized CBD stones
Healthy cystic duct and common bile duct
Absence of significant CBD strictures
Absence of impacted stones or extensive debris burden
Patient amenable to laparoscopic approach.
Contraindications For Transcystic:
Large or multiple impacted CBD stones
Significant CBD strictures or dilatations
Acute cholangitis with hemodynamic instability
Poorly functioning cystic duct or anatomy unsuitable for cannulation
Suspected periampullary tumors.
Preoperative Preparation
History And Physical Exam:
Assess for symptoms of choledocholithiasis (jaundice, RUQ pain, fever)
Evaluate for signs of cholangitis or pancreatitis
Obtain detailed past surgical history.
Diagnostic Imaging:
MRCP is the gold standard for preoperative stone detection
Ultrasound can detect CBD dilation and stones
ERCP may be diagnostic and therapeutic but carries risks
Intraoperative cholangiogram (IOC) confirms patency and identifies residual stones.
Laboratory Tests:
Complete Blood Count (CBC) for leukocytosis
Liver Function Tests (LFTs) including bilirubin, ALT, AST, ALP, GGT to assess biliary obstruction
Coagulation profile (PT/INR) to assess synthetic function.
Antibiotics Prophylaxis:
Broad-spectrum intravenous antibiotics (e.g., ceftriaxone and metronidazole) should be administered preoperatively to cover enteric flora, especially if cholangitis is suspected or instrumentation of the biliary tree is planned.
Procedure Steps
Access And Cholecystectomy:
Standard laparoscopic or open cholecystectomy is performed
The cystic duct is identified and dissected free.
Cystic Duct Cannulation:
The cystic duct is cannulated using a specialized transcystic introducer sheath or a suitable catheter
Careful dissection and identification of the cystic duct opening are paramount.
Insertion Of Instruments:
Once the sheath is in place, instruments like flexible choledochoscopes, guidewires, balloon catheters, or stone retrieval baskets can be introduced into the CBD.
Stone Removal And Clearance:
Stones are carefully grasped with baskets or extracted with balloons
If stones are too large, they may be fragmented using lithotripsy (laser or electrohydraulic) or removed piecemeal
Confirmation of clearance is essential.
Intraoperative Cholangiogram:
An IOC is performed by injecting contrast through the cystic duct to confirm stone clearance, assess CBD patency, and visualize any residual stones or anatomical abnormalities
Images are reviewed in real-time.
Postoperative Care
Monitoring:
Vital signs, fluid balance, urine output
Monitor for signs of bleeding, infection (cholangitis), pancreatitis, or bile leak
LFTs are typically repeated postoperatively.
Pain Management:
Adequate analgesia is crucial
Patient-controlled analgesia (PCA) may be used
Monitor for opioid-related side effects.
Drainage:
A drain may be placed in the subhepatic space depending on surgeon preference or if complications are suspected
Drains are typically removed when output is minimal and serosanguinous.
Dietary Advancement:
Diet is advanced as tolerated, starting with clear liquids
Patients can usually resume a regular diet within a few days.
Discharge Criteria:
Afebrile, tolerating oral intake, minimal pain, ambulating, and passing flatus
No signs of bile leak or significant complications.
Complications
Early Complications:
Bile leak from cystic duct stump or CBD injury
Cholangitis (postoperative sepsis)
Pancreatitis
Bleeding
Injury to adjacent structures (e.g., hepatic artery, portal vein)
Retained CBD stones.
Late Complications:
Biliary stricture
Recurrent choledocholithiasis
Bile duct cancer (rare association)
Adhesions
Incisional hernia.
Prevention Strategies:
Meticulous surgical technique
Accurate identification of anatomy
Careful cannulation of the cystic duct
Complete stone clearance confirmed by IOC or choledochoscopy
Appropriate antibiotic prophylaxis
Judicious use of drains.
Key Points
Exam Focus:
Indications and contraindications for transcystic approach
Role of IOC and choledochoscopy
Management of retained stones
Complications and their management
Differentiating transcystic from transductal exploration.
Clinical Pearls:
Gentle manipulation is key to avoid injury
A healthy, wide cystic duct is essential for safe passage of instruments
If difficulty is encountered, do not force instruments
consider converting to open exploration or ERCP
Always confirm stone clearance.
Common Mistakes:
Attempting transcystic exploration in unsuitable anatomy
Inadequate stone clearance
Forcing instruments leading to injury
Not performing an IOC when indicated
Failing to recognize and manage early signs of complications.