In the past, surgical biliary drainage was often performed for biliary obstruction.^[1] With the advancement of endoscopic instrumentation and accumulation of experience of endoscopists, the successful rate in treating biliary diseases by endoscopy has been increasing markedly. Endoscopic therapy without general anaesthesia and laparotomy has the advantages of less wound, less pain, rapid recovery, short hospital stay and affirmative curative effect.^[2,3] Many patients need not receive further surgical treatment. This study summarises the experience with biliary drainage by duodenoscope for biliary obstruction at our hospital from January 1998 to December 2002.

Methods

Patients

Endoscopic biliary drainage was performed in 352 patients with biliary obstruction, of whom 165 were men and 187 women, aged from 17 to 89 years (mean 68.7 years). 153 patients (43.5%) were over 70 years. All patients had symptoms of abdominal pain, jaundice or fever. Among them, 140 patients had acute obstructive supurrative cholangitis, 111 choledocholithiasis, 53 benign biliary stricture, and 46 malignant biliary tumor. Biliary operation was performed more than 2 times in 57 patients. Fourty-three patients presented with concomitant severe diseases such as arrhythmia, chronic obstructive pulmonary diseases, cerebrovascular suddenness or chronic renal dysfunction.

Methods

Electronic duodenoscope (Olympus, TJF-200, 240, Tokyo, Japan) was used. Endoscopic retrograde cholangiopancreatography (ERCP) was performed, followed by endoscopic sphincterotomy (EST) if intubation was difficult. When the cause of biliary obstruction was confirmed, the way of biliary drainage could be determined. Endoscopic naso-biliary drainage (ENBD) was performed for patients with acute cholangitis, and EST or endoscopic papillary balloon dilatation (EPBD) for those with choledocholithiasis. Stones were extracted via different approaches such as basket, balloon and basket lithotripsy. For benign biliary stricture, endoscopic retrograde biliary drainage (ERBD) with plastic stent or ENBD was indicated after stricture dilation with balloon. On the other hand, endoscopic metal biliary endoprothesis (EMBE) with metallic stent or ERBD was used for malignant biliary stricture.

Results

Endoscopic biliary drainage

ENBD, ERBD and EMBE were performed in 258, 51 and 43 patients, respectively. Of the 352 patients, 337 were successfully drainaged. The symptoms of the 140 patients with acute supperrative cholangitis relieved 24 hours after ENBD. Among these patients, 107 received endoscopic treatment again after the cause of the disease was determined, but 33 patients accepted operation. Sixty-eight of the 111 patients with choledocholithiasis showed the clearance of stones in the common bile duct, whereas 43 patients with residual stones received endoscopic extraction again. Of the 53 patients with benign biliary obstruction who were followed up for 4 months after ERBD, 28 had plastic stents removed because of stricture relief, 21 had stent replacement, 4 underwent operation following percutaneous transhepatic biliary drainage (PTBD) after failure of ERBD. The 46 patients with malignant biliary stricture were subjected to EMBE showing reduced serum bilirubin and improved quality of life. The mean duration of drainage in all the patients was 43.3 days with a range of 1 to 193 days, including 8.1 days for ENBD, 132.5 days for ERBD, and 156.7 days for EMBE.

Drainage failure and countermeasures

Endoscopic biliary drainage failed in 15 patients, including ENBD (10 patients), ERBD (3) and EMBE (2). In the 10 patients, the naso-biliary tube was folded in the oral pharynx, gastric lumen or bile duct (4 patients) (Fig. 1), slided from the bile duct when withdrawal of the endoscope (3), dropped because of intense cough and vomiting (2), and pulled up incautiously. Successful drainage, however, was performed by modulating the site of the tube or reinserting another tube.ª¥

Fig. 1. The naso-biliary tube folds in the gastric lumen.

Fig. 2. The plastic stent could not reach and exceed the biliary stricture.

Fig. 3. The metallic stent could not exceed the tumor stricture site.

Fig. 4. Another metallic stent is replaced through a previous prothesis.

In the 3 patients who failed in ERBD (Fig. 2), 2 were successfully drainaged using stents with an appropriate length. In another patient, the wide caliber of stent and great resistence of placement made insertion unsuccessful, percutaneous transhepatic biliary drainage (PTBD) was performed because of failure of re-insertion.ª¥

In the 2 patients who failed in EMBE, one patient undergoing radical gastrectomy had a widespread metastasis in the abdominal cavity, causing compression of the bile duct. The metallic stent could not exceed the site of tumor stricture and the drainage failed (Fig. 3). Another patient presented with symptoms of biliary obstruction again for tumor implantation confirmed by ERCP only 1 month after EMBE. Either a metallic or plastic stent was replaced through previous prothesis to restore fluent drainage (Fig. 4).

Discussion

Value and indications of endoscopic biliary drainage

For biliary obstruction, traditional surgical treatment is generally applied. But the risk of operation is great for the elder patients with such diseases as diabetes mellitus, hypertension, cardiorespiratory dysfunction, and so on. Some patients have had several biliary operations and widespread adhesion formed in the abdominal cavity, making the subsequent operation more difficult. The rates of complication and death during and after surgery are thus increased. Recent development of endoscopic techniques enables many patients with biliary obstruction to have a fluent drainage via endoscope instead of surgical procedure.ª¥

Patients with biliary obstruction caused by benign or malignant diseases are indicated for endoscopic procedure. Bile leakage is also indicated for endoscopic treatment,^[4] but the treatment is not advisable if the symptoms of the disease can not be relieved or satisfactory results can not be achieved, in such conditions as multiple intrahepatic cholangiocarcinoma, widespread intrahepatic metastatic carcinoma, and severe blood coagulation. To prevent massive bleeding, endoscopic biliary drainage should be performed cautiously for patients with portal hypertension and severe esophageal varices. Since the metallic stent can not be taken out once it has been implanted and scar-restenosis is likely to occur because of repeated ulceration caused by friction between the end of the stent and the bile duct wall, researchers suggest benign bile duct diseases a contraindication of EMBE.^[5]

Cautions for ENBD

During ENBD, withdrawal of an endoscope should be synchronous with insertion of the tube under a fluoroscope after the naso-biliary tube is located. The pushing tube must be connected to the drainage tube if necessary until the tip of a duodenoscope is retreated from the mouth. The assistant should fix the tube tightly to prevent it from being brought out. Attention is given to prevent pulling out of the tube too fast in case that it folds and slides from the bile duct, space and the drainage tube must be fixed firmly in vitro.

Cautions for ERBD

To make the placement of plastic stent successful, the bile duct should always be dilated transitorily. Prior to the insertion of the stent, contrast media in the bile duct which can not be drained should be sucked out as far as possible to avoid cholangitis or pyohemia. Selection of suitable plastic stent is dependent on the stricture of the bile duct. The diameter of the stent for those patients with severe biliary constriction is appropriate to 10 Fr or below because the effect of stents with a diameter of 12 Fr and 14 Fr is not better than that of the stent with a diameter of 10 Fr. Two stents should be placed simultaneously to drain respectively the left and right hepatic ducts because of tumor oppression of the porta hepatis. The stents should be deployed with their distal ends above the ampulla of Vater in patients with strictures that do not extend to the lower end of the common bile duct to minimize the occurrence of bacterial colonization and to reduce the risk of the stent clogged by food stuff.ª¥

The main cause affecting the long-term effect of ERBD is the occlusion of stent.^[6] In general, occlusion due to bile encrustation is less frequent in plastic stents with a large internal diameter. If the occlusion causes drainage failure, the stent should be removed and replaced endoscopically. Another cause is the migration of stent, but the incidence of migration is lower than that of occlusion of stent. To avoid the migration, some migration-resistant designs such as double-mushroom stents and spirals are recommended.

Cautions for EMBE

EMBE has become an effective therapy in treating malignant biliary tumor.^[7] Metallic stent should be selected according to obstructive position and length, the characteristics of stent and so on. The stent should exceed the tumor 2 cm in length in order to prevent overgrowing from obstruction. The proximal end of the stent should be placed in the peripheral intrahepatic duct, ensuring a stable position and minimizing the risk of overgrowth in patients with hilar strictures. The distal end of the stent should be left in the duodenum to allow endoscopic recanalization if necessary. The optimal position of the distal end of the stent is 1 to 2 cm inferior to the ampulla of Vater. In patients whose left and right hepatic ducts are obstructed, it is necessary to insert bilateral stents. For porta hepatis tumor, metallic stent must be placed cautiously because widespread biliary obstruction may result in worse drainage or severe cholangitis. Other transitional procedures such as ENBD and ERBD should be used first. When the effect of ENBD or ERBD is satisfactory and inflammation is controlled, alteration of metallic stent is much safer.ª¥

The main cause affecting the long-term effect of EMBE is also the occlusion of stent, including tumor overgrowing into the stent, bile encrustation and tumor necrosis tissues blocking the stent. It is still effective to relieve obstruction, however, if metallic or plastic stent is reinserted into the blocked stent. It has been reported that the metallic stent covered with a layer of polyurethane can be effective to prevent the invasion of tumor tissue and prolong the patency of the stent.^[8]

Competing interest

No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.

References

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3 Zhou PH, Yao LQ, Gao WD,et al. Endoscopic diagnosis and treatment of post-cholecystectomy syndrome. Chin J Dig Endosc 2001;18:335-338.

4 Raijman I, Catalano MF, Hirsch GS, et al. Endoscopic treatment of biliary leakage after laparoscopic cho-lecystectomy. Endoscopy 1994;26:741-744.

5 Sung JJY, Chung SCS. Endoscopic stenting for palliation of malignant biliary obstruction: a review of progress in the last 15 years. Dig Dis Sci 1995;40:1167-1168.

6 Shim CS, Kim JH, Cho SW. Clinical study of endoscopic retrograde biliary drainage (ERBD) in malignant obstructive jaundice. Korean Int Med 1988;35:644-651.

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8 Shim CS, Lee YH, Cho YD, et al. Prelimilary results of a new covered biliary metal stent for malignant biliary obstruction. Endoscopy 1998;30:345-350.

Received May 26, 2003

Accepted after revision August 6, 2003