Strategies for stenting benign postoperative strictures.|
Biliary strictures follow 0.25% to 2% of biliary surgical procedures.
The risk of bile duct injury is significantly greater with laparoscopic (0.5 to 2%) than open (0.25%) cholecystectomy. The incidence of laparoscopic cholecystectomy-related bile duct injury has not continued to decrease with time, suggesting a higher complication rate inherent to the procedure.
Anatomical variation or severe inflammation may predispose to bile duct injury. Many injuries, however, stem from errors in identifying and dissecting the gallbladder and cystic duct.
Strictures often follow partial or complete bile duct transection from inadvertent clip placement or ligation. Occasionally, strictures are caused by ischemia from dissection or a thermal injury.
Post-laparoscopic cholecystectomy strictures tend to be short (< 10 mm). They commonly occur at the mid common bile duct, and confluence of the right and left hepatic ducts. Patients may present with signs of biliary obstruction and cholangitis.
In some instances, an associated proximal biliary fistula masks signs of obstruction.
However, it may take several weeks for ligation of the right or left hepatic duct to present with cholangitis and abnormal liver tests.
Strictures have traditionally been treated surgically.
The aim is to obtain a tension-free, mucosa-mucosa anastomosis between unscarred bile duct and the proximal intestine. Typically a Roux-en-Y hepaticojejunostomy is performed. While initially a good response occurs in the majority (75%-93%), recurrent strictures occur in 12%-45%. Additionally, surgical morbidity (18%-51%) and mortality (4%-13%) are high.
Proximal bile duct strictures may be associated with even less optimal results. The majority of stricture recurrences occur within 7 years of surgical repair.
Percutaneous biliary dilation of postoperative bile duct strictures has a reported success rate of between 33% and100%, with a long-term patency rate of 76%. Several sessions are required to obtain a satisfactory outcome.
The principal complications of this procedure are related to the passage of catheters and instruments across the hepatic parenchyma, and include hemorrhage and biliary leakage. In addition, a significant proportion of patients has no intrahepatic biliary dilation, making the procedure more difficult and prone to complications.
Recurrence rates tend to be high and, unlike endoscopic therapy, percutaneous dilation cannot be carried out safely in the presence of ascites, cirrhosis, or coagulopathy.
This usually consists of stricture dilation, followed by the placement of 1 or multiple stents across the stricture at 3 to 4 month intervals, for approximately 1 year.
It is believed that once sufficient dilation is achieved, fibrotic tissue remodeling will prevent elastic recoil and recurrence of the stenosis. Rapid biliary decompression can usually be attained.
An unsuccessful endoscopic attempt does not preclude percutaneous or surgical management.
Broad-spectrum prophylactic antibiotics are routinely administered and generally full strength contrast is used, unless stones are suspected.
A biliary sphincterotomy is usually performed. This facilitates placement of multiple stents as well as repeated cannulations, and may reduce the risk of pancreatitis.
Detailed cholangiography is necessary to accurately delineate anatomy.
While considerable variation exists, the typical endoscopic management consists of dilation using a balloon or sequential catheter dilators, followed by insertion of two 10 F stents. These are changed every 3 months to prevent occlusion and cholangitis.
When strictures cannot be traversed endoscopically, percutaneous cholangiography with subsequent "rendezvous" procedure is performed.
For tight strictures, it is sometimes necessary to initially insert a single 7 F or 10 F stent for 6-8 weeks. This is to partially dilate the stricture before larger and/or multiple stents can be placed.
In very high-grade stenosis, sometimes a 5 F or 6 F nasobiliary catheter is inserted and left in situ for 24-48 hours before ERCP is repeated and a stent is placed. On occasion, only a guidewire can be passed across the stricture. This is left in for 24 hours, after which dilation is accomplished.
Although good results occur in approximately 80% of cases, endoscopic stenting is not universally embraced as definitive therapy. It is argued that recurrent strictures appear years after therapy.
However, results of a 9-year follow-up of 74 patients with benign biliary strictures, who underwent endoscopic stenting, are impressive. The recurrent stricture rate was only 20%, at a median follow up of 9.1 years. Most cases of recurrent stenosis occurred within 2 years of stent removal .
Costamanga, et al recently published their experience . Here, increasing numbers of stents were inserted at subsequent procedures, incrementally increasing the radial force. The mean number of stents increased from 1.7 to 3.2. Stenting was continued until no residual stricture remained.
The mean duration of treatment was 12.1 months (range 2 to 24 months), with the mean number of ERCPs per patient at 4.1 (range 2 to 8).
On an intention-to-treat basis, 40/45 (89%) patients had successful treatment. None of the 40 patients had symptoms from stricture recurrence. The mean duration of follow-up was 48.8 months.
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It is generally believed that strictures treated within 3 months of diagnosis are more likely to respond to endoscopic therapy. However, the 2 previous studies found no difference in eventual outcome with either the early or late detection of strictures.
Age, sex, as well as anatomic location, presence of bile leakage, and number of ERCPs required for initial stent placement, were all found to not be significant prognostic factors.
Surgery versus endoscopy
At 1 institution,101 patients underwent endoscopic and surgical treatment of benign bile duct strictures . These patients were managed by a combined group of surgeons and endoscopists, and outcome parameters were prospectively defined.
In both, the surgically and the endoscopically treated groups, a good or excellent result was achieved in 83% of patients. Recurrent stricturing occurred in 17% of both groups.
Early complications were more common in the surgically treated group. On the other hand, late complications (most were related to stent clogging) were more common in the endoscopically treated group.
Metal stents in benign bile duct strictures
Despite reports of long-term patency rates, placement of expandable metal stents in benign biliary strictures remains controversial. Once placed, the stents are not usually removable without surgical resection.
Animal and human studies show that significant ductal epithelial hyperplasia is induced by metal stents. Membrane coated expandable stents may, however, make this type of stenting more attractive in the future.
In a recently published series of 15 patients with metal stents placed for benign strictures (about half of these were related to choledocholithiasis), the mean patency rate was 30.6 months.
Some 2 of 3 patients required further intervention for recurrent cholangitis and obstruction. Of concern was the finding of cholangiocarcinoma in 1 patient who had a metal stent for 10 years. Surgical removal of the stent was complicated because of the associated severe bile duct inflammation.
These include perforation of the bile duct within the stricture zone during attempted dilation or stent placement. If this occurs within the liver parenchyma, it is usually of little significance. Perforations of the extrahepatic bile duct may result in biliary leak.
Cholangitis commonly occurs as a result of stent occlusion, especially if strict every-3-month exchange protocols are not followed. Residual stricturing may also present with cholangitis.
The short-term complication rates are higher for surgery than endoscopy, with the opposite being true when long-term complications are considered. Percutaneous management carries increased risk because the hepatic parenchyma and peritoneal cavity are violated.
Endoscopic stenting plays an important role in the management of bile duct strictures. This modality offers definitive treatment in most patients with benign bile duct strictures.
Endoscopic therapy is relatively safe and does not preclude subsequent surgery. Patients with complete duct transection, as well as those who have failed endoscopic therapy, should undergo surgical bypass.
Uncoated metallic stents, with their high occlusion rates and lack of removability, are unsuitable for benign biliary strictures. Membrane coated stents, biodegradable stents, and drug impregnated stents may possibly be viable alternatives in the future.
There are many unanswered questions as to what constitutes the most optimal endoscopic approach. It appears that placement of multiple stents is effective.
The duration of stenting, as well as what constitutes a suitable end-point to stenting, has yet to be defined.
Incrementally increasing the number of stents at each endoscopic session until the stricture is eliminated appears an effective strategy.
If this approach is adopted, under what circumstances is endoscopic failure deemed to have occurred?
Apart from the complete duct transections, are there subgroups of patients (such as those with hilar stenosis) who are better served with an initial surgical approach?
Bergman JJ, Burgmeister L, Bruno MJ, Rauws EA, Gouma DJ, Tytgat GNJ, et al. Long-term follow up after biliary stenting for postoperative bile duct stenosis. Gastrointest Endosc 2001;54:154-161.
- Costamagna G, Pandolfi M, Mutigani M, et al. Long-term results of endoscopic management of postoperative bile duct strictures with increasing number of stents. Gastrointest Endosc 2001;54:162-8.
- Davids PH, Tanka AK, Rauws EA, van Guilk TM, Van Leeuwen DJ, de Wit LT ,et al. Benign biliary strictures. Surgery or endoscopy? Ann Surg 1993; 217:237-243 Ann Surg 1993; 217:237-243.