Clin Endosc.  2020 Nov;53(6):735-742. 10.5946/ce.2020.003.

Inside Plastic Stents versus Metal Stents for Treating Unresectable Malignant Perihilar Biliary Obstructions: A Retrospective Comparative Study

• Kanno Y
• Koshita S
• Ogawa T
• Kusunose H
• Masu K
• Sakai T
• Yonamine K
• Miyamoto K
• Murabayashi T
• Kozakai F
• Horaguchi J
• Noda Y
• Ito K

• KMID: 2511234
• DOI: http://doi.org/10.5946/ce.2020.003

Abstract

Background/Aims
The aim of this study was to evaluate outcomes of inside plastic stents (iPSs) versus those of metal stents (MSs) for treating unresectable perihilar malignant obstructions.
Methods
For all patients who underwent endoscopic suprapapillary placement of iPS(s) or MS(s) as the first permanent biliary drainage for unresectable malignant perihilar obstructions between January 2014 and August 2019, clinical outcomes using iPSs (n=20) and MSs (n=85), including clinical efficacy, adverse events, and time to recurrence of biliary obstruction (RBO), were retrospectively evaluated.
Results
There were no differences in clinical effectiveness (95% for the iPS group vs. 92% for the MS group, p=1.00). Procedure-related adverse events, including pancreatitis, acute cholangitis, acute cholecystitis, and death, were observed for 8% of the MS group, although no patient in the iPS group developed such adverse events. The median time to RBO was 561 days (95% confidence interval, 0–1,186 days) for iPSs and 209 days (127–291 days) for MSs, showing a significant difference (p=0.008).
Conclusions
Time to RBO after iPS placement was significantly longer than that after MS placement. IPSs, which are removable, unlike MSs, were an acceptable option.

Keyword

Above the papilla; Benign stricture; Bile duct cancer; Endoscopic retrograde cholangiopancreatography; Hilar cholangiocarcinoma

Figure

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  Fig. 1. Inside stents placed above the papilla (arrows). (A) Inside plastic stents; and (B) inside metal stents placed using a partial stent-in-stent method.

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  Fig. 2. Kaplan–Meier curves of cumulative rates to recurrent biliary obstruction (RBO). Median times to RBO were 561 (95% confidence interval [CI], 0–1,186) days for the inside plastic stent (iPS) group and 209 (95% CI, 127–291) days for the metal stent (MS) group (p=0.008).

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  Fig. 3. Kaplan–Meier curves of cumulative rates to recurrent biliary obstruction (RBO) for patients who did versus did not undergo chemotherapy (Cx). (A) Median times to RBO (TRBO) were 284 (95% confidence interval [CI], 195–373) days for patients who underwent Cx after the procedure and 209 (95% CI, 112–306) days for patients who did not (p=0.13). (B) For the inside plastic stent (iPS) group, median TRBO times were 636 days (95% CI, not available) for patients who underwent Cx and 211 days (95% CI, not available) for those who did not; for the metal stent (MS) group, they were 265 (95% CI, 162–368) days and 164 (95% CI, 54–274) days (p=0.028).

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  Fig. 4. Kaplan–Meier curves indicating cumulative survival rates. (A) Median survival periods were 329 (95% confidence interval [CI], 181–477) days for the inside plastic stent (iPS) group and 224 (95% CI, 149–298) days for the metal stent (MS) group (p=0.37). (B) Median survival periods were 238 (95% CI, 148–328) days for patients who underwent chemotherapy (Cx) and 153 (95% CI, 74–232) days for those who did not (p=0.011).

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