Clinical History
Persistent jaundice (serum bilirubin in the range 6-9 mg/dL) during postoperative hospitalisation following urgent laparoscopic cholecystectomy for acute cholecystitis, in a previously healthy man.
Imaging Findings
On the fifth postoperative day, urgent Magnetic Resonance Cholangiopancreatography (MRCP) was requested. A non-haemorrhagic collection occupied the gallbladder fossa, reached by the drainage tube. Moderately dilated intrahepatic ducts were seen in both lobes; the common hepatic duct (CHD) also appeared dilated (7 mm) with an abrupt termination; the CHD stump measured 14 mm in length, consistent with a type II injury according to the Bismuth classification. Caudally to the ductal discontinuity, normal-caliber choledochus was identifiable.
Contrast-enhanced MDCT (including multiplanar, MIP and MinIP reformations) confirmed MRCP findings, with better identification of metallic clips obstructing CHD with moderate upstream biliary dilatation.
Endoscopic Retrograde Cholangiopancreatography (ERCP) was performed to dynamically test common bile duct patency: injected contrast medium opacified up to the level of the surgical clips and not above, indicating tight stenosis.
During surgical reoperation, clips obstructing the CHD were removed and a biliary stent was positioned.
Discussion
Iatrogenic bile duct injuries represent serious, potentially life-threatening complications causing postoperative morbidity and prolonged hospitalisation. Incidence reaches 0.5% and 1.2% following open and laparoscopic cholecystectomy, respectively. Most usually, biliary obstruction results from surgeon’s misinterpretation of either normal or variant anatomy, such as clipping or ligation of the common hepatic duct mistaken as the cystic duct [1-4].
Often unrecognised intraoperatively, ductal injuries after cholecystectomy are suggested by postoperative pain, sepsis or jaundice. Their severity and long-term consequences vary greatly. In the past, Endoscopic Retrograde Cholangiopancreatography (ERCP) and Percutaneous Transhepatic Cholangiography (PTC) were needed to visualise biliary anatomy before surgical repair of iatrogenic injuries, but these invasive procedures may have serious complications. As with this patient, with common bile duct transection ERCP shows no opacification above the clips. Intrahepatic and CHD dilatation with an abrupt cut-off is usually observed during PTC [1, 2, 4]
Currently, Magnetic Resonance Cholangiopancreatography (MRCP) is considered the primary imaging modality to evaluate suspected iatrogenic biliary injuries. MRI safety during the immediate postoperative period is not a concern since most surgical clips are made from nonferromagnetic material. Urgent MRCP allows rapid, accurate assessment of presence, level and length of injury, plus detection of subhepatic collections. Key findings include intrahepatic biliary dilatation with associated discontinuity in a ductal segment, persistently observed comparing thick sections with coronal source images [2, 3, 5].
Possible MRCP pitfalls include a tendency to overestimate minimal calibre changes as moderate duct dilatation, and magnetic susceptibility artefacts due to metallic clips [3, 5]. MRCP allows differentiation of biliary obstruction caused by mistakenly placed clips from other causes including retained gallstones, fibrosis from thermal injury from cautery devices, and extrinsic compression by a fluid collection [2, 6].
Providing comprehensive visualisation of the biliary tract above and below the level of the obstruction, MRCP allows correct staging of iatrogenic injuries and therefore optimal treatment planning. The Bismuth classification system differentiates type I (occurring more than 2 cm distal from the biliary confluence) from type II injuries (located less than 2 cm from the biliary bifurcation); the CHD stump is absent with intact confluence in type III, whereas type IV injury completely or partially damages the biliary confluence [1-3, 5]. Alternatively, as demonstrated with this case multiplanar reformations (exploiting MIP and MinIP techniques) from MDCT acquisition may demonstrate hyperdense metallic clips with upstream biliary dilatation.
Differential Diagnosis List
Bismuth type II postoperative bile duct transection injury following cholecystectomy
Residual biliary lithiasis
Thermal bile duct damage
Biliary obstruction from extrinsic compression
Postoperative acute pamcreatitis
Final Diagnosis
Bismuth type II postoperative bile duct transection injury following cholecystectomy
