Copyright ©The Author(s) 2016.
World J Gastrointest Endosc. Jan 25, 2016; 8(2): 77-85
Published online Jan 25, 2016. doi: 10.4253/wjge.v8.i2.77
Table 1 Current stent failure rates
Stent typeStent failure rates in malignant obstruction
Plastic stents30%-70%
Self expanding metal stents19%-46%
Table 2 Causes of stent failure
Causes of stent failurePercent of total failures
Tumor ingrowth66%-68%
Epithelial ingrowth
Biliary clogging17%-21%
Tumor overgrowth2%-11%
Stent migration0%-4%
Table 3 Studies evaluating drug elution or coating to prevent internal failure
Ref.JournalStudy designStudy results
In vitro
Rees et al[17]Journal of Hospital Infection (1998)In vitroBZC and Teflon reduced the number of organisms attached to stents
- control (polyurethane)
- benzalkonium chloride (BZC)
- ePTFE (Teflon)
Cetta et al[18]The European Journal of Surgery (1999)In vitroHeparin and hyaluronic acid coating reduced biofilm development
5 stents - control (polyurethane)
5 stents - heparin + hyaluronic acid
Weickert et al[21]Advances in Medical Sciences (2011)In vitroStents coated with hydrophobin or both hydrophobin and heparin reduced clogging material scanning electron microscopy (SEM) images
7 stents - control (polyethylene)
4 stents - hydrophobin (H)
3 stents - H + ampicillin/sulbactam
3 stents - H + levofloxacin
3 stents - H + heparin
Gwon et al[22]Acta Radiologica (2012)Canine modelCefotaxime did not prevent biofilm development (gross inspection, SEM images)
3 stents - control (ePTFE)
3 stents - 10% wt/vol cefotaxime
3 stents - 20% wt/vol cefotaxime
Farnbacher et al[19]Scandinavian Journal of Gastroenterology (2012)Randomized prospectiveHeparin is effective in preventing encrustation on stents (encrustation weighed)
13 stents - control (polyethylene)
13 stents (same patients) - heparin
Table 4 Trials evaluating systemic treatments to prevent internal failure
Ref.JournalStudy designStudy results
Barrioz et al[48]Lancet (1994)Randomized prospectiveDrugs were associated with longer stent patency and shorter hospital stay
25 - conservative treatment
21 - ursodeoxycholic acid and norfloxacin
Coene et al[49]Scandinavian Journal of Gastroenterology (1994)Randomized prospectiveBile clogging did not correlate with bile viscosity. Mucolytic agents or antibiotics only effective when bile is highly viscous
60 patients received either
co-trimoxazole or
Smit et al[50]Gastrointestinal Endoscopy (1989)Randomized prospectiveBoth doxycycline and aspirin reduced the dry weight of sludge. Doxycycline improved patient survival
30 patients received either
placebo or
doxycycline or
HalmEndoscopy (2001)Randomized prospectiveNo difference in patient survival or stent occlusion
26 - ursodeoxycholic acid
26 - ursodeoxycholic acid + ofloxacin
De Lédinghen et al[51]Digestive Diseases and Sciences (2000)Randomized prospectiveNo difference in stent patency and patient survival
29 - conservative treatment
33 - ursodeoxycholic acid and norfloxacin
In vitro
Tsang et al[52]Journal of Laboratory and Clinical Medicine (1997)In vitroAmpicillin and sulbactam inhibited biofilm formation
4 - porcine bile
4 - porcine bile + ampicillin + sulbactam
Table 5 Studies evaluating drug elution or coating to prevent external failure
Ref.JournalStudy designStudy results
Lee et al[38]Gastrointestinal Endoscopy (2005)Porcine modelPaclitaxel-eluting stents caused mild adverse effects, but are safe to use in porcine models
2 pigs - control (metallic)
2 pigs - 10% wt/v Paclitaxel
2 pigs - 20% wt/v Paclitaxel
Lee et al[40]Gastrointestinal Endoscopy (2009)Canine modelPaclitaxel-eluting stents caused mild adverse effects, but are safe to use in canine models
5 dogs - control (metallic)
6 dogs - 20% wt/v paclitaxel
Lee et al[44]International Journal of Pharmaceutics (2012)In vitro, murine modelStents coated with gemcitabine reduced the size of subcutaneous tumor in vitro and in mice
5 mice - no stenting
5 mice - polyurethane
5 mice - 0% wt/v gemcitabine
5 mice - 8% wt/v gemcitabine
5 mice - 12% wt/v gemcitabine
Chung et al[45]Journal of Gastroenterology and Hepatology (2012)Porcine modelGemcitabine-eluting stents cause mild to severe inflammation, but are safe to use in porcine models
2 pigs - 0% wt/v gemcitabine
2 pigs - 10% wt/v gemcitabine
2 pigs - 15% wt/v gemcitabine
2 pigs - 20% wt/v gemcitabine
Jang et al[41]Endoscopy (2012)Porcine modelGreater patency observed when stents were coated with pluronic with paclitaxel. Stents are safe to use in porcine models
2 pigs - 0% wt/v paclitaxel
2 pigs - 0% Pluronic + 10% taxol
2 pigs - 10% Pluronic + 10% taxol
2 pigs - 20% Pluronic + 10% taxol
Kim do et al[46]International Journal of Nanomedicine (2013)In vitro, murine modelSorafenib-loaded film inhibited the growth of human cholangiocarcinoma cells in vitro and in mice
10 mice - control (no stenting)
10 mice - PCL film
10 mice - sorafenib-loaded film
Shi et al[42]European Journal of Gastroenterology and Hepatology (2013)Canine modelNo adverse effects
10 dogs - control (no stenting)less granulation tissue and glandular hyperplasia in dogs with paclitaxel stents
10 dogs - Poly-L-lactic acid coated metallic stents (PLLA)
10 dogs - PLLA + 1 mg paclitaxel/stent
10 dogs - PLLA + 2 mg paclitaxel/stent
Bang et al[43]Gastroenterology Research and Practice (2015)Murine modelTumor angiogenesis inhibited in mice with Paclitaxel stents through multiple molecular mechanisms
8 mice - control (polyurethane)
8 mice - control + Pluronic
8 mice - Pluronic + 5% paclitaxel
8 mice - Pluronic + 10% paclitaxel
Suk et al[2]Gastrointestinal Endoscopy (2007)Randomized prospectivePaclitaxel-eluting stents are safe and effective. Occlusion in 9 patients, mean patency was 429 d
21 patients - 10% wt/v paclitaxel
Jang et al[3]Digestive Diseases and Sciences (2013)Randomized prospectiveNo significant differences in stent patency or patient survival, but stents proved safe to use in humans
46 patients - control (metallic)
60 patients - 10% wt/v paclitaxel