Usefulness of Multiplanar Reformatted Images of Multi-detector Row Helical CT in Assessment of Biliary Stent Patency

PURPOSE: To evaluate the usefulness of multi-detector row helical CT (MDCT), multiplanar reformatted images for the noninvasive assessment of biliary stent patency, and for the planning for management in patients with a self-expandable metallic stent due to malignant biliary obstruction. MATERIALS AND METHODS: Among 90 consecutive patients, from August 1999 to July 2003, 26 cases in 23 patients with malignant biliary obstruction who underwent self-expandable metallic stent insertion in the biliary system and percutaneous transhepatic biliary drainage within 7 days after CT were enrolled in this study. On CT images, the complete and functional obstruction of the stent and the precise level of obstruction were evaluated. The presence of an enhancing intraluminal mass or wall thickening around stent was determined, and the causes of obstruction were evaluated. These findings were then compared with percutaneous transhepatic cholangiography. RESULTS: Multi-detector row helical CT correctly demonstrated the patency of a stent in 24 cases (92.3%). It was adequate in helping to depict the precise level of stent occlusion in 23 cases (88.5%). Multi-detector row helical CT also revealed the extent of tumor that represented as an enhancing intraluminal mass or wall thickening around the stent in 23 cases, and this was represented as complete obstruction on percutaneous transhepatic cholangiography. In the case of functional obstruction, MDCT predicted the possible cause of the obstruction. CONCLUSION: Multiplanar reformatted images of multi-detector row helical CT is a useful imaging modality for the noninvasive assessement of stent patency and the precise level of obstruction when stent obstrution is suspected in the patients with self-expandable metallic stent due to malignant biliary obstruction. It can also predict the possible cause of the obstruction and allows adequate planning for the medical management of such cases.

Utility of MR Cholangiography for Follow-up Examination after Metallic Stent Placement in the Bile Duct

PURPOSE: To evaluate the efficacy of MR cholangiography for follow-up examination after metallic stent placement in the bile duct. MATERIALS AND METHODS: Between December 1999 and June 2000, 15 patients with biliary obstruction in whom metallic biliary stents had been placed underwent MR cholangiography during follow-up examination. The causes of obstruction were hilar cholangiocarcinoma (n=6), common bile duct cancer (n=5), gall bladder cancer (n=1) and pancreatic cancer (n=3). The types of self-expandable metallic stent employed were the nitinol stent (n=2), the Endocoil nitinol stent (n=3), the Ultraflexed Diamond stent (n=5), and the Wallstent (n=5). Using MR cholangiography, we measured the diameter of that part of the biliary stent which showed high signal intensity, assigning one point if this was less than one third of the stent diameter, two points if between one third and two thirds, and three points if more than two thirds. We decided that a higher score indicated fewer artifacts. RESULTS: The score was 1.7-3 (mean, 2.3) points for the Endocoil nitinol stent, 1.7-2.3 (mean, 2) for the nitinot stent, and 1-3 (mean, 1.7) for the Ultraflex Diamond stant. In most cases, two thirds of the stent diameter was observed. For the Wallstent, the score was 1-1.7 (mean, 1.3) points and the inner portion of the stent was almost invisible. CONCLUSION: MR cholangiography is not useful for follow-up examination after the placement of Wallstents and three other types of nitinol stent in the bile duct.

Intraluminal Brachytherapy after Metallic Stent Placement in Primary Bile Duct Carcinoma

PURPOSE: To determine the effect of intraluminal brachytherapy on stent patency and survival after metallic stent placement in patients with primary bile duct carcinoma. MATERIALS AND METHODS: Twenty-seven patients with primary bile duct carcinoma underwent metallic stent placement; in 16 of the 27 intraluminal brachytherapy with an iridium-192 source (dose, 25 Gy) was the performed. Obstruction was due to either hilar (n=14) or non-hilar involvement (n=13). For statistical comparison of patients who underwent/did not undergo intraluminal brachytherapy, stent patency and survival were calculated using the Kaplan-Meier method and an independent t test. RESULTS: The mean durations of stent patency and survival were 9.1 and 10.0 months respectively in patients who underwent intraluminal brachytherapy, and 4.2 and 5.0 months in those who did not undergo this procedure (p<0.05). The mean durations of stent patency and survival among the 22 patients who died were 7.6 (range, 0.8 -16.1) and 8.3 (range, 0.8-17.3) months, respectively, in the eleven patients who underwent intraluminal brachytherapy, and 4.2 (range, 0.9-8.0) and 5.0 (range, 0.9-8.4) months in those whom the procedure was not performed (p<0.05). CONCLUSION: Intraluminal brachytherapy after stent placement extended both stent patency and survival in patients with primary bile duct carcinoma.

Percutaneous Placement of Self-expandable Metallic Biliary Stents in Malignant Extrahepatic Strictures: Indications of Transpapillary and Suprapapillary Methods

OBJECTIVE: To compare the efficacy of suprapapillary and transpapillary meth-ods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. MATERIALS AND METHODS: Stents were placed in 59 patients. Strictures were cat-egorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. RESULTS: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapap-illary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p =0.37) or method (p = 0.62). CONCLUSION: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

Percutaneous Placement of Self-expandable Metallic Biliary Stents in Malignant Extrahepatic Strictures: Indications of Transpapillary and Suprapapillary Methods

OBJECTIVE: To compare the efficacy of suprapapillary and transpapillary meth-ods of transhepatic biliary metallic stent placement in malignant biliary strictures and to specify the indications of each method applied. MATERIALS AND METHODS: Stents were placed in 59 patients. Strictures were cat-egorized as type A (within 3 cm of the ampulla, n = 27), type B (over 3 cm from ampulla, n = 7), type C (within 3 cm of the bending portion, n = 9), or type D (over 3 cm above the bending portion, n=16). The stenting method was suprapapillary in 34 cases and transpapillary in 25. The rates of initial and long-term patency and of early recurrence were compared. RESULTS: Initial patency rates for the suprapapillary and transpapillary methods were 1/7 (14.3%) and 20/20 (100%) respectively for type A (p < 0.0001), 4/5 (80.0%) and 2/2 for type B, 3/7 (42.9%) and 2/2 for type C, and 15/16 (93.8%) and 0/0 for type D. Early recurrence rates were 7/30 (23.3%) using the suprapap-illary method and 4/29 (13.8%) using the transpapillary method (p = 0.51). The long-term patency rate did not differ significantly according to either type (p =0.37) or method (p = 0.62). CONCLUSION: For good initial patency, the transpapillary method is recommended for strictures of the distal extrahepatic duct near the ampulla and just above the bending portion. Long-term patency is not influenced by the stenting method employed.

Management of Advanced Hilar Biliary Malignancy with X-shaped Stenting Technique

PURPOSE: To report X-shaped stent insertion and its result in the patients with advanced hilar malignancy. MATERIALS AND METHODS:X-shaped stents were inserted in six patients with advanced hilar malignancy involving segmental branches of both intrahepatic bile ducts (IHD). The causes were cholangiocarcinomas in five patients and recurrent GB cancer in one. The procedure includes three steps: 1) the insertion of two wires through three IHDs in an X configuration, using a stone basket; 2) balloon dilatation of lesions, and 3) the in-sertion of two stents in an as X configuration. Stents were inserted after balloon dilatation in five patients, and without balloon dilatation in one. Changes in serum bilirubin levels and procedure-related problems were reviewed. RESULTS: In all patients, serum bilirubin levels gradually decreased, but in two, they increased again. One of these two died of sepsis after 1 month. There was bile leakage through the puncture and bile was extracted from malignant ascites. In the other patient, occlusion of the left stent tip occurred, and additional left PTBD was performed 3 months later. Hemobilia developed in all five patients with balloon dilatation, these all experianced pain during dilatation , but afterwards this disappeared. One stent without pre-balloon dilation showed incomplete self-expansion at the crossing part and supplementary balloon dilatations were performed. CONCLUSION: In patients with advanced hilar malignancy, X-shaped stent insertion is a new palliation. Problems such as hemobilia, pain, and intraperitoneal bile leakage may, however, occur.