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Intrahepatic Bile Duct Stricture—Etiology, Evaluation, and Treatment

An isolated intrahepatic bile duct stricture or injury is uncommon. When it occurs, it can be a vexing problem. Following hepatic trauma or operation, an intrahepatic duct may be injured directly or from ischemia. Typically this is an asymptomatic finding noted during follow up imaging. The ducts proximal to the site of trauma or surgery are dilated and do not require therapy. It would be rare for a patient to develop either pain or cholangitis in the area of the dilated ducts that required therapy. Pain in this circumstance is treated symptomatically with medication. Cholangitis in the affected bile ducts is treated with antibiotics and drainage by placement of a percutaneous transhepatic catheter (PTC). In either case, persistent or recurrent symptoms may require resection of the affected hepatic segments, although this would be rare.

Equally problematic is the finding of asymptomatic intrahepatic biliary dilation (imaging done for another indication or for vague upper abdominal symptoms) without a history of injury or a known inflammatory process. The concern with this finding is distinguishing a benign versus malignant etiology. The presence of a mass in conjunction with an isolated ductal stricture raises the likelihood of cholangiocarcinoma, which should be treated accordingly. However, in the absence of a mass, the differential diagnosis includes a small (non-mass forming) cholangiocarcinoma, IgG4-related or unilobular primary sclerosing cholangitis, or a nonspecific inflammatory stricture. Practically, these are difficult to separate from each other. An elevated serum IgG4 is consistent with IgG4 sclerosing cholangitis, which is treated with a course of steroids. In the absence of an elevated IgG4 or a response to a course of steriods, however, it is difficult or impossible to rule out a small cholangiocarcinoma. Hence, hepatectomy of the affected bile duct and its surrounding parenchyma becomes the practical treatment option for this presentation.

Finally, another cause of intrahepatic biliary strictures is recurrent pyogenic cholangitis (oriental cholangiohepatitis), which is endemic in Southeast Asia. While uncommon in the USA, the incidence is increasing in the West as a result of immigration. Stone formation in the intrahepatic ducts leads to multiple ductal strictures and cholangitis. While the details are beyond the scope of this chapter, the treatment is multidisciplinary combining radiological, endoscopic, and surgical approaches.

Most commonly, the initial finding of biliary dilation is by ultrasonography or computed tomography. Definitive imaging, however, begins with contrast-enhanced magnetic resonance imaging (MRI) including an MR cholangiogram. This defines the ductal and vascular anatomy and detects any associated masses. Cholangiography, whether percutaneous or endoscopic, may be helpful in some cases to define the anatomy, perform biopsies (although the diagnostic yield is low), or drain the occluded ducts. A non-operative approach is rarely definitive therapy, though. In patients with a chronic stricture, hepatic parenchymal atrophy, in the distribution of the obstructed ducts, is commonly seen on cross-sectional imaging. Jaundice does not occur in patients with hemi-lobar or smaller areas of atrophy unless there is concurrent hepatic parenchymal disease or dysfunction.

Sectoral Bile Duct Injury Management

Strasberg classifies sectoral bile duct injuries following cholecystectomy as Type B, C, E4 and E5. Type B and C injuries are isolated sectoral (typically right posterior) ductal injuries, usually due to aberrant right hepatic ductal anatomy. E4 injuries involve a stricture at the confluence of the right and left hepatic ducts, effectively isolating the right and left ductal systems. An E5 injury is a combination of an aberrant right sectoral bile duct injury and an E4 stricture. Each of these injuries requires a different approach for treatment.

The critical first step in treating this group of patients is to control any bile leak and treat their sepsis. Typically one begins by percutaneous drainage of all bilomas. If this is insufficient, a laparoscopic approach with abdominal irrigation and drain placement is helpful, particularly if diffuse bile peritonitis is present. Following treatment of the bile peritonitis or biloma, a contrast enhanced MRI and MRCP is done to elucidate the biliary and vascular anatomy. Establishing the status of the right hepatic artery is important as the incidence of concurrent right hepatic artery occlusion in patients with a biliary injury is estimated to be > 20 %. Furthermore, right hepatic artery occlusion is associated with a higher rate of anastomotic stricture following repair; thus, it impacts the timing and nature of the repair.

The type of bile duct injury dictates the approach to biliary drainage; the goal in all cases is to effectively drain each isolated segment/sector of the biliary tract. This may require placement of one or more PTCs. We usually wait a minimum of 12 weeks following control of sepsis and the biliary tract prior to pursuing definitive surgical therapy. This allows for resolution of the acute inflammation that accompanies biliary sepsis or biloma and the evolution of any additional bile duct stricturing that may occur as a result of a thermal or ischemic injury. In addition, this gives time for the development of collateral circulation to the right ducts and liver from the intact left hepatic arterial branches. Because of the tenuous nature of high hilar injuries or a minimal length of the residual aberrant right sectoral duct, this approach seems prudent to insure an optimal, well vascularized repair. We consider and perform immediate repair (<7 days from injury) for less complex injuries (E1 and E2) in patients without sepsis or right hepatic artery occlusion.

Strictures that appear late (>3 months) usually have an insidious onset of symptoms (jaundice or pain) and don’t have bilomas or an acute inflammatory component. Once the biliary anatomy is fully understood and appropriate preoperative management is completed, the patient can be taken to surgery for definitive repair. Regardless of the antecedent presentation, before a patient is taken to the operating room for definitive surgical repair, it is critical that a complete cholangiogram is performed. We find three-dimensional cholangiography or cholangiography combined with computed tomography helpful in complex cases to insure the entire biliary tract has been defined and to understand the anatomy. Prior to repair, each isolated bile duct segment/sector should have a PTC placed within it and the tip advanced to the distal most part of the duct. This significantly facilitates intraoperative identification of the occluded bile duct(s). We work closely with our interventional radiologist to manage these patients, as their expertise is essential to successful therapy.

Type B injuries limited to a sectoral duct, in the absence of cholangitis, tend to be asymptomatic. These do not require therapy. Rarely, a patient may present with persistent right upper quadrant abdominal pain due to the atrophic sector and strictured, dilated duct. Alternatively, and also rare, they may develop cholangitis in the atrophic, obstructed sector. Resection of the affected sector, following PTC drainage and antibiotics if cholangitis is present, is appropriate therapy. If a type B injury of the main right hepatic duct occurs, this may present early with serum liver test abnormalities or cholangitis; asymptomatic lobar atrophy usually presents late as an incidental finding. Again rarely, patients may present late with persistent pain attributable to the stricture and/or lobar atrophy. If a main right hepatic duct occlusion is discovered early, it is treated preoperatively as outlined previously followed by definitive restoration of bilioenteric continuity with a Roux-en-Y hepaticojejunostomy . When a patient has lobar atrophy and cholangitis or pain, or has a concurrent right hepatic artery injury, right hepatectomy is a safe and effective treatment option.

Type C injuries are discovered acutely due to symptoms from the bile leak. Consequently, when they are ready for definitive therapy, treatment is restoration of bilioenteric continuity by hepaticojejunostomy. If the duct is a sectoral duct and very small, ligation is an option, but not preferred due to the risk of cholangitis developing in the ligated ductal system.

Type E4 and E5 injuries require complex repairs as outlined in prior publications. A key feature to these repairs, as well as some type C repairs is division of the cystic plate at its junction with the anterior right portal pedicle to allow access to the right bile duct(s). Exposure of the bile ducts at the portal plate require lowering of the portal plate (Hepp-Couinaud approach); using the ultrasonic dissector to excavate or resect liver around the end of the normal or aberrant right hepatic duct facilitates additional exposure, if necessary.

Other technical tips include cutting the end of the PTC tube flush with the ductotomy and placing a retaining suture through the cut end of the tube. The tube is then pulled up into the duct proximal to the ductotomy. In this way, the tube can be pulled down into the area of the anastomosis with the retaining suture, if necessary. If not, the suture is cut and removed prior to completing the anastomosis. By doing this, the tube is not in the anastomosis when it is constructed. We find this much easier than trying to construct the anastomosis around a tube within the ductotomy. We do not stent the bilioenteric anastomosis with a PTC or other tube. One only has to look at the inflammatory changes present in the common bile duct after placement of a plastic endoprosthesis to appreciate the extent of the inflammatory reaction from these tubes. Empirically, this cannot be healthy for the bilioenteric anastomosis, particularly since many of these are done to relatively small ducts. The PTC tube is left proximal to the anastomosis and prior to discharge a cholangiogram is performed. If there is no leak and the anastomosis is widely patent, the tube is removed before the patient goes home. If there is anastomotic edema, leak or other problem, we leave the tube in place for several weeks and repeat the cholangiogram later. If needed, the PTC can be exchanged and advanced through the anastomosis.

Another important issue is fastidious construction of a mucosal to mucosal anastomosis between healthy biliary and jejunal epithelium. To insure the jejunal mucosa is present at the anastomosis, the mucosa is always tacked to the serosa at the jejunotomy site using interrupted 6–0 absorbable monofilament sutures. This looks similar to a colostomy when finished and insures that the jejunal mucosa opposes the biliary epithelium in the anastomosis. This is particularly useful when doing an anastomosis to a small duct with limited visibility. Finally, the anastomosis is constructed in a fashion described by Blumgart many years ago. We use interrupted 6–0 or 5–0 monofilament absorbable sutures to construct the anastomosis. The anterior row is placed first as this tents open the duct orifice and facilitates placement of the posterior row of sutures. The posterior row sutures are placed so that the knot will be tied within the anastomosis. After placing the posterior row sutures, the bowel is “parachuted down” to the bile duct and the posterior sutures tied. Prior to placing the anterior row of sutures, place the tip of a right angle clamp through the open anterior portion of the anastomosis and into the bowel, opening the clamp to insure that none of the anterior mucosa is trapped in the anastomosis. This prevents partial anastomotic obstruction from mucosal bands. Since the jejunal mucosa was already tacked to the serosa, it is relatively easy to place the anterior sutures through the jejunotomy, confident that the mucosa is present at the site of apposition with the bile duct. The anterior sutures are tied externally. A closed suction drain is placed in the sub-hepatic space.

Sectoral bile duct injuries are challenging clinical situations. As a result, following the fundamental principles outlined in this chapter and the associated references are essential to obtaining an optimal therapeutic outcome.