Gastroenterology Research and Practice

Gastroenterology Research and Practice / 2018 / Article

Research Article | Open Access

Volume 2018 |Article ID 6527879 | https://doi.org/10.1155/2018/6527879

Chuanguo Zhou, Baojie Wei, Jianfeng Wang, Qiang Huang, Hui Li, Kun Gao, "Self-Expanding Metallic Stent Fracture in the Treatment of Malignant Biliary Obstruction", Gastroenterology Research and Practice, vol. 2018, Article ID 6527879, 10 pages, 2018. https://doi.org/10.1155/2018/6527879

Self-Expanding Metallic Stent Fracture in the Treatment of Malignant Biliary Obstruction

Academic Editor: Michel Kahaleh
Received16 Nov 2017
Revised13 Dec 2017
Accepted18 Dec 2017
Published10 Apr 2018

Abstract

Background. Palliative therapies for malignant biliary obstruction (MBO) include choledochojejunostomy and self-expanding metallic stent (SEMS) insertion. Fractures following SEMS insertion in MBO treatment are scarce. Objective. To assess the clinical features of biliary stent fractures and evaluate associated factors. Methods. One hundred fifty-six consecutive patients who underwent biliary SEMS placement for MBO treatment at Beijing Chaoyang Hospital affiliated to Capital Medical University, in 2010–2015, were evaluated retrospectively. Demographics, clinical features, stent parameters and patency times, and survival times were collected. Across the ampulla of Vater, balloon dilatation, number of stents, stent patency time, and survival time were compared between the stent and nonstent fracture groups. Results. There were 168 biliary metallic stents inserted in 156 patients, including 144 and 12 patients with one and 2-3 stents, respectively. Pre- and/or postballoon dilation was performed in 107 patients. Stents across and above the duodenal papilla were used in 105 and 51 patients, respectively. Six cases (3.8%) with stent occlusion had stent fractures. Single- and multiple-stent fracture rates were 4/144 (2.8%) and 2/12 (16.7%), respectively. Fracture times after stent deployment were 126.8 ± 79.0 (median, 115.5) days. Stent patency times in the stent and nonstent fracture groups were 151.8 ± 67.8 (median, 160.5) days and 159.3 ± 73.6 (median, 165.5) days, respectively. Overall survival times in the stent and nonstent fracture groups were 399.7 ± 147.6 (median, 364.0) days and 283.7 ± 126.1 (median, 289.0) days, respectively. Conclusion. Stent fractures following MBO treatment constitute a relatively rare long-term complication. Though there were no factors found to be significantly associated with SEMSs fracture, a trend could be observed towards more fractures in multistent, transpapillary, and balloon dilation groups.

1. Introduction

Malignant biliary obstruction (MBO) refers to the blockage of the biliary tree by direct malignant tumor infiltration or external compression; the underlying malignancies in the vast majority of cases are cholangiocarcinomas and pancreatic head carcinomas. Other tumors in this region include cystic, duodenal, and gastric cancers, as well as intrahepatic and hilar lymph node metastases [1]. Commonly, the clinical manifestation of MBO is painless jaundice, with anorexia and weight loss. Infection secondary to malignant bile duct obstruction may result in cholangitis, symptoms of the digestive tract, hepatic failure and renal insufficiency, sepsis, and even death. Despite recent advances in radiology, only approximately 20% of periampullary tumors are resectable at the time of diagnosis, because of invasiveness, metastasis, and poor performance status [2]. The available options for palliative therapy of malignant biliary tree obstruction include choledochojejunostomy, percutaneous external/internal drainage or metallic stent placement, and endoscopic techniques. Recent evidence indicates the superiority of self-expanding metallic stents (SEMSs) over plastic stents, with regard to stent patency time, complications rates, and reinterventions. In selected subgroups of patients, SEMS placement may have survival benefits [3]. Short-term complications of SEMS insertion include cholangitis, asymptomatic increase of amylase levels, and bleeding. Long-term complications comprise stent occlusion due to tumor ingrowth or overgrowth, stent migration, and viscus perforation [4]. Few reports have described stent fractures following SEMS insertion in the treatment of malignant biliary obstruction [511]. The present study aimed at assessing the clinical features of biliary stent fractures in six cases and identifying factors that may affect biliary stent fractures.

2. Materials and Methods

The study was reviewed and approved by the ethics committees of Beijing Chaoyang Hospital affiliated to Capital Medical University according to the standards of the Declaration of Helsinki. Written informed consent was waived because of the retrospective nature of this study. All patient records were anonymized and deidentified before analysis.

A total of 156 consecutive patients who underwent biliary SEMS placement with percutaneous transhepatic approach for the treatment of MBO at Beijing Chaoyang Hospital affiliated to Capital Medical University between January 2010 and September 2015 and were not suitable for surgery or declined resection for poor performance status were enrolled in this retrospective study. Most of the patients with malignant biliary obstruction were accompanied by cholangitis. To the patients which have no cholangitis but with obvious gastrointestinal symptoms accompanied by intrahepatic biliary dilatation and serum total bilirubin above 150 μmol/L, they were also treated by biliary drainage and stent implantation. Obstruction location, stent type, number of stents placed, placement across the duodenal ampulla, and predilation or postdilation were recorded. If applicable, stent fracture data were extracted from patient records and relevant imaging findings. Malignant biliary obstructions include “distal” and “proximal” obstruction types. Distal biliary obstruction refers to an obstruction below the main hepatic ducts’ confluence. In such cases, the entire biliary tree could be drained with a single stent without requiring an external catheter.

3. Interventional Procedure

According to preoperative computed tomography scan (CT) or magnetic resonance imaging (MRI) data, the optimal puncture point in most cases was 2–4 cm below the right cardiophrenic angle at the axillary midline. A 22-gauge double-walled needle, for example, the Chiba needle, was advanced under fluoroscopic guidance. The stylet was removed, and the contrast agent was gently injected while retracting the needle until opacification of the bile duct. Once the target bile duct was accessed, a 0.018 wire was advanced into the duct through a coaxial system, and the wire was upsized to a 0.035 guide wire. A 7.0–8.5 French biliary drainage catheter (COOK Inc., Bloomington, IN, United States) was inserted into the dilated biliary duct under wire guidance. Two to four weeks later, serum total bilirubin levels were decreased to almost normal amounts, and cholangitis was controlled, with the patient’s general condition improved. Then, the uncovered nitinol SEMSs (COOK Inc., Bloomington, IN, United States) were implanted. Through an 8F sheath, a directional catheter in combination with a hydrophilic guide wire was used to cross the biliary obstruction and advanced into the small bowel. An appropriately sized stent may be inserted, usually 8 or 10 mm in diameter and 40 to 100 mm in length. According to the degree of biliary stenosis and stent expansion, pre- or postdilation with balloon catheter was selected. Cholangiography via the sheath after stent deployment was used to assess stent patency. In case of satisfactory contrast agent flow, the sheath was removed, with the puncture tract plugged with gel foam pledges. Stent fracture was defined as persistent or recurrent jaundice, and cholangiography revealed bile duct obstruction, with interruption of biliary stent continuity or deficiency of the biliary stent segment.

4. Perioperative Treatment

All patients received 150 mg of magnesium isoglycyrrhizinate, 40 mg of pantoprazole, and 6 g (three doses) of cefoxitin sodium intravenously guttae at the day of the procedure. Continuous intravenous infusion of octreotide 0.3 mg was administered before procedure to prevent acute pancreatitis. Postoperative serum amylase levels were used to determine whether to continue intravenous octreotide administration. Nausea, vomiting, abdominal pain, and other symptoms were treated as well. The patients were followed up via outpatient appointments or by telephone interviews every 3 months to 1 year after the procedure. The last follow-up occurred in May 2017.

5. Statistical Analysis

Statistical analyses were performed with the SPSS 22.0 software (SPSS, United States). Quantitative data are expressed as mean ± SD and were compared by unpaired -test; categorical variables were compared by the Chi-square test or Fisher’s exact test. Stent patency time and survival time were derived by the Kaplan–Meier method and compared using the log-rank test. Two-tailed was considered statistically significant.

6. Results

A total of 156 patients were treated during the study period, including 94 men (65.6 ± 11.4 years old) and 62 women (68.6 ± 12.0 years old). Biliary obstructions in these patients were pancreatic cancer (), cholangiocarcinoma (), malignant gastric carcinoma (), cancer of the ampulla of Vater (), gallbladder carcinoma (), colon cancer metastasis (), lung cancer metastasis (), and ovary cancer metastasis (). The success rate of the biliary stent procedure was 100%. A successful procedure consists of gastrointestinal symptoms relieved, total bilirubin decreased to almost normal, and biliary stent well positioned and patent. All patients had “distal” biliary obstruction. The most common short-term complications included cholangitis, asymptomatic amylase increase, and biliary bleeding. Long-term complications comprise stent occlusion due to tumor ingrowth or overgrowth and stent fractures. There were no patients who had stent migration, viscus perforation, or seeding (Table 1).


Type of complicationsPatients

Short-term complicationsCholangitis33 (21.2%)
Asymptomatic amylase increase21 (13.5%)
Biliary bleeding8 (5.1%)
Long-term complicationsIngrowth86 (55.1%)
Overgrowth43 (27.6%)
Stent fractures6 (3.8%)

There were 168 biliary metallic stents inserted in 156 patients, including 144 and 12 (7.7%) patients with one and 2-3 stents, respectively. Pre- and/or postballoon dilation was performed in 107 patients; the remaining patients did not undergo balloon dilation. Stent across and above the duodenal papilla was adopted in 105 and 51 patients, respectively. Six cases (3.8%) with stent occlusion had stent fractures. Single- and multistent fracture rates were 4/144 (2.8%) and 2/12 (16.7%), respectively. Mean and median fracture times after stent deployment were 126.8 ± 79.0 days and 115.5 days, respectively. Meanwhile, stent patency times in the stent and nonstent fracture groups were 151.8 ± 67.8 (median, 160.5) days and 159.3 ± 73.6 (median, 165.5) days, respectively. Overall survival times in the stent and nonstent fracture groups were 399.7 ± 147.6 (median, 364.0) days and 283.7 ± 126.1 (median, 289.0) days, respectively. The characteristics of these six patients are summarized in Tables 2 and 3 and Figures 16.


Nonstent fracture ()Stent fracture ()/ value

Sex, M/F90/604/20.1070.55
Mean age ± SD, years67.1 ± 11.676.0 ± 8.01.8520.07
Above the ampulla, n5103.0310.09
Across the ampulla, n996
Nondilation, n4902.8580.10
Balloon dilation, n1016
Single stent, n14045.7780.07
Multistent, n102
Stent patency time, days159.3 ± 73.6 (median, 165.5)151.8 ± 67.8 (median, 160.5)0.4140.52
Survival time, days283.7 ± 126.1 (median, 289.0)399.7 ± 147.6 (median, 364.0)5.9520.16

SD: standard deviation, Nonstent fracture versus stent fracture groups.

PatientCase 1Case 2Case 3Case 4Case 5Case 6

Age, gender62, male81, female82, male82, male71, male78, female
Primary diseasePancreatic carcinomaPancreatic carcinomaPancreatic carcinomaPancreatic carcinomaCholangiocarcinomaDuodenal ampulla carcinoma
Level of obstructionDistalDistalDistalDistalDistalDistal
Parameters of stent10 mm × 80 mmFirst stent, 8 mm × 60 mm; next two stents, 8 mm × 60 mm10 mm × 60 mm8 mm × 80 mmFirst stent, 10 mm × 40 mm; second stent, 10 mm × 100 mm8 mm × 60 mm
Number of stentsOneThreeOneOneTwoOne
Pre-/postdilationYesYesYesYesYesYes
Across the ampullaYesYesYesYesYesYes
Time to stent fracture (days)893765179142249
Patency time of the stent (days)8918765179142249
Overall survival time (days)241312335393662455

10 mm is the stent diameter and 80 mm the length. Time to stent fracture is defined as the time period from last stent insertion to stent fracture.

7. Discussion

Biliary stent placement is widely used in the treatment of a variety of malignant biliary obstruction cases. For patients with malignant biliary obstruction and life expectancy exceeding 3 months, self-expandable metal stent deployment is the standard treatment option [12, 13]. There are two techniques for biliary stent insertion, including endoscopic and percutaneous hepatic approaches; nevertheless, there has not been a uniform conclusion published on either the efficacy of the two types of drainage or the incidence rate of complications. The procedure’s success rate is nearly 100% [5].

Common short and long-term complications include cholangitis, asymptomatic increase of amylase, and occlusion due to tumor ingrowth or overgrowth [14, 15]. To the best of our knowledge, only 7 reports have described a total of 13 patients with fractures of metallic biliary stents placed to relieve malignant biliary obstruction (Table 4) [511]. The incidence of biliary stent fracture is approximately 7–22% [7, 9]; in this study, it was 3.8%. Biliary reobstruction is expected from disease progression, but stent failure due to fracture is usually not suspected and thus probably overlooked and underreported. Therefore, it is difficult to estimate the exact incidence rate of biliary stent fractures.


Authors (years)PatientsPrimary diseaseTime to fractureNumber of stentsType of stentTreatment of stent fracture

Peck and Wattam [7]/66
Female ()
Male ()
Age, 78.5 ± 5.6 years
Pancreatic carcinoma (); cholangiocarcinoma (); recurrent cholangitis ()Median fracture times, 225 daysOne stent in each patientNitinol stentReimplantation
Yoshida et al. [5]82, malePancreatic carcinoma5 monthsOneNitinol stentReimplantation
Sriram et al. [10]63, femaleCholangiocarcinoma6 monthsOneNitinol stentReimplantation
Yoshida et al. [6]82, maleCholangiocarcinoma18 monthsTwoNitinol stentReimplantation
Rasmussen et al. [9]/48
Female ()
Male ()
Age, 71.3 ± 13.8 years
Cancer of the papilla of Vater (); pancreatic ()Median fracture times, 392 daysOne stent in each patientNitinol stentReimplantation
Saravanan et al. [8]50, maleBenign biliary anastomotic strictureNAOneNitinol stentThe surgical intervention
Alkhiari et al. [11]67, femaleRecurrent cholangitisNAOneNitinol stentRemove the fractured stent by endoscopy

Biliary stent fractures occurred in 4/66 patients after biliary stent implantation.

Nitinol is an alloy consisting of 55% nickel and 45% titanium. Its biocompatibility as well as unusual and useful properties of shape memory explains its widespread use in medicine. Stents may be exposed to significant stress-induced fatigue, which may weaken the metallic structure over time, leading to subsequent fracture and fragmentation [16]. Nitinol SEMSs are widely used in the management of stenosis affecting vascular and nonvascular vessels, such as the coronary artery, lower extremity artery, subclavian vein, and esophagus [1621]. The most common factors which may affect stent fractures may include balloon dilation or stent overexpansion, stent overlap, stent length, stent type and stent conformability, and tortuous and highly angulated vessels [13, 22]. The anatomic sites of biliary stent fractures varied; most were located at overlapping stents, tumor sites, or the ampulla, with distal stent disconnection. This may be related to increased cutting force, which caused significant stress-induced fatigue and resulted in fracture. The possibility of disease- or treatment-related factors leading to stent fracture has been considered.

The present study showed that the multistent fracture rate (16.7%) was higher than the single stent counterparts (2.8%) (). The differences not reaching statistical significance may be due to the small sample size. The interactions between the stents and stent geometry during multistent implantation are considered the most important factor in biliary obstruction fractures. In addition, duodenal peristalsis and tumor compression can promote stent fracture occurrence. Operation-related factors, such as selecting stent size, passing the stent across the ampulla (), and pre- or postdilation (), may also contribute to stent fracture development [17]. Concerning stent patency time, no significant difference between the fracture and nonfracture groups was obtained (). As shown above, the survival time difference () may be related to the advanced age of patients, low-grade malignancy, and the small sample size. Treatment of biliary stent fractures includes reimplantation of the biliary stent, indwelling of a new biliary drainage catheter, and partial removal of the fractured stent by endoscopy.

In conclusion, stent fracture occurs after insertion of self-expanding nitinol stents for the treatment of malignant biliary obstruction, as a relatively rare long-term complication. The reported low incidence of this complication may be due to lack of awareness about stent fractures and the difficulty in detecting them. Though there were no factors found to be significantly associated with SEMSs fracture, a trend could be observed towards more fractures in multistent, transpapillary, and balloon dilation groups.

Conflicts of Interest

The authors declare that they have no conflicts of interest.

References

  1. S. Jaganmohan and J. H. Lee, “Self-expandable metal stents in malignant biliary obstruction,” Expert Review of Gastroenterology & Hepatology, vol. 6, no. 1, pp. 105–114, 2014. View at: Publisher Site | Google Scholar
  2. L. Z. C. T. Pu, R. Singh, C. K. Loong, and E. G. H. de Moura, “Malignant biliary obstruction: evidence for best practice,” Gastroenterology Research and Practice, vol. 2016, Article ID 3296801, 7 pages, 2016. View at: Publisher Site | Google Scholar
  3. M. A. Almadi, A. Barkun, and M. Martel, “Plastic vs. self-expandable metal stents for palliation in malignant biliary obstruction: a series of meta-analyses,” The American Journal of Gastroenterology, vol. 112, no. 2, pp. 260–273, 2017. View at: Publisher Site | Google Scholar
  4. R. J. H. Schaafsma, P. Spoelstra, J. Pakan, and K. Huibregtse, “Sigmoid perforation: a rare complication of a migrated biliary endoprosthesis,” Endoscopy, vol. 28, no. 5, pp. 469-470, 1996. View at: Publisher Site | Google Scholar
  5. H. Yoshida, T. Tajiri, Y. Mamada et al., “Fracture of a biliary expandable metallic stent,” Gastrointestinal Endoscopy, vol. 60, no. 4, pp. 655–658, 2004. View at: Publisher Site | Google Scholar
  6. H. Yoshida, Y. Mamada, N. Taniai et al., “Fracture of an expandable metallic stent placed for biliary obstruction due to common bile duct carcinoma,” Journal of Nippon Medical School, vol. 73, no. 3, pp. 164–168, 2006. View at: Publisher Site | Google Scholar
  7. R. Peck and J. Wattam, “Fracture of memotherm metallic stents in the biliary tract,” CardioVascular and Interventional Radiology, vol. 23, no. 1, pp. 55-56, 2000. View at: Publisher Site | Google Scholar
  8. M. N. Saravanan, V. Mathai, D. Kapoor, and B. Singh, “Fractured metallic biliary stent causing obstruction and jejunal perforation,” Asian Journal of Endoscopic Surgery, vol. 6, no. 3, pp. 234–236, 2013. View at: Publisher Site | Google Scholar
  9. I. C. Rasmussen, U. Dahlstrand, G. Sandblom, L. G. Eriksson, and R. Nyman, “Fractures of self-expanding metallic stents in periampullary malignant biliary obstruction,” Acta Radiologica, vol. 50, no. 7, pp. 730–737, 2009. View at: Publisher Site | Google Scholar
  10. P. V. Sriram, A. Ramakrishnan, G. V. Rao, and D. Nageshwar Reddy, “Spontaneous fracture of a biliary self-expanding metal stent,” Endoscopy, vol. 36, no. 11, pp. 1035-1036, 2004. View at: Publisher Site | Google Scholar
  11. R. Alkhiari, V. Patel, and L. Cohen, “Spontaneous fracture of a covered self-expandable biliary metal stent and endoscopic technique for removal,” Canadian Journal of Gastroenterology and Hepatology, vol. 28, no. 8, 412 pages, 2014. View at: Publisher Site | Google Scholar
  12. J. Y. Kim, G. B. Ko, T. H. Lee et al., “Partially covered metal stents may not prolong stent patency compared to uncovered stents in unresectable malignant distal biliary obstruction,” Gut and Liver, vol. 11, no. 3, pp. 440–446, 2017. View at: Publisher Site | Google Scholar
  13. P. Rossi, M. Bezzi, M. Rossi et al., “Metallic stents in malignant biliary obstruction: results of a multicenter European study of 240 patients,” Journal of Vascular and Interventional Radiology, vol. 5, no. 2, pp. 279–285, 1994. View at: Publisher Site | Google Scholar
  14. H. Yarmohammadi and A. M. Covey, “Percutaneous biliary interventions and complications in malignant bile duct obstruction,” Chinese Clinical Oncology, vol. 5, no. 5, p. 68, 2016. View at: Publisher Site | Google Scholar
  15. S. J. Lee, M. D. Kim, M. S. Lee et al., “Comparison of the efficacy of covered versus uncovered metallic stents in treating inoperable malignant common bile duct obstruction: a randomized trial,” Journal of Vascular and Interventional Radiology, vol. 25, no. 12, pp. 1912–1920, 2014. View at: Publisher Site | Google Scholar
  16. H. S. Khara, D. L. Diehl, and S. A. Gross, “Esophageal stent fracture: case report and review of the literature,” World Journal of Gastroenterology, vol. 20, no. 10, pp. 2715–2720, 2014. View at: Publisher Site | Google Scholar
  17. M. Chinikar and P. Sadeghipour, “Coronary stent fracture: a recently appreciated phenomenon with clinical relevance,” Current Cardiology Reviews, vol. 10, no. 4, pp. 349–354, 2014. View at: Publisher Site | Google Scholar
  18. N. Neil, “Stent fracture in the superficial femoral and proximal popliteal arteries: literature summary and economic impacts,” Perspectives in Vascular Surgery and Endovascular Therapy, vol. 25, no. 1-2, pp. 20–27, 2013. View at: Publisher Site | Google Scholar
  19. A. Mallios, K. Taubman, P. Claiborne, and J. Blebea, “Subclavian vein stent fracture and venous motion,” Annals of Vascular Surgery, vol. 29, no. 7, pp. 1451.e1–1451.e4, 2015. View at: Publisher Site | Google Scholar
  20. G. Coppi, R. Moratto, J. Veronesi, E. Nicolosi, and R. Silingardi, “Carotid artery stent fracture identification and clinical relevance,” Journal of Vascular Surgery, vol. 51, no. 6, pp. 1397–1405, 2010. View at: Publisher Site | Google Scholar
  21. F. Damas-De Los Santos, F. Colombo, A. Zuffi, and A. Cremonesi, “Vertebral-subclavian bifurcation treatment. “the wedding ring technique” for a vertebral in-stent restenosis associated with stent fracture,” Gaceta Médica de México, vol. 151, no. 5, pp. 655–659, 2015. View at: Google Scholar
  22. M. K. Mohsen, A. Alqahtani, and J. Al Suwaidi, “Stent fracture: how frequently is it recognized?” Heart Views, vol. 14, no. 2, pp. 72–81, 2013. View at: Publisher Site | Google Scholar

Copyright © 2018 Chuanguo Zhou et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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