• Korean Chemical Engineering Research
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• v.58 no.1
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• pp.36-43
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• 2020

A biliant stent was fabricated using a magnesium alloy wire, a biodegradable metal. In order to control the fast decomposition and corrosion of magnesium alloys in vivo, magnesium alloy wires were coated with biodegradable polymers such as polycaprolactone (PCL), poly(propylene carbonate) (PPC), poly (L-lactic acid) (PLLA), and poly (D, L-lactide-co-glycolide) (PLGA). In the case of PPC, which is a surface erosion polymer, there is no crack or peeling compared to other polymers (PCL, PLLA, and PLGA) that exhibit bulk erosion behavior. Also, the effect of biodegradable polymer coating on the axial force, which is the mechanical property of magnesium alloy stents, was investigated. Stents coated with most biodegradable polymers (PCL, PLLA, PLGA) increased axial forces compared to the uncoated stent, reducing the flexibility of the stent. However, the stent coated with PPC showed the axial force similar to uncoated stent, which did not reduce the flexibility. From the above results, PPC is considered to be the most efficient biodegradable polymer.

• Journal of Yeungnam Medical Science
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• v.22 no.2
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• pp.211-220
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• 2005

Background: The purpose of this study was to determine the effectiveness of a percutaneously placed self-expanding metallic stent for the relief of biliary obstruction in patients with hilar cholangiocarcinoma. Materials and Methods: From November 2001 to December 2004, 48 patients with hilar cholangiocarcinoma were prospectively studied. After percutaneous placement of bilateral selfexpanding, uncovered metallic stents, follow-up evaluation was carried out until July 2005. Results: There were 4 cases of Bismuth type II, 21 cases of Bismuth type IIIa, 8 cases of Bismuth type IIIb and 15 cases of Bismuth type IV. Stent placement was technically successful in all patients. All patients had satisfactory biliary drainage, resulting in one week drainage rate of 72.8% and final drainage rate of 91.1%. There were 12 cases (21.3%) of abdominal pain requiring analgesics and 1 case (7.1%) of cholangitis; both were successfully managed with conservative treatments. Late complications occurred in four patient (8.3%), including two patients with cholangitis, one patient with liver abscess, and one patient with biloma; all were appropriately managed by percutaneous drainage. The average length and median durations of stent patency and median survival time were 303 days (range, 60~815) and 338 days (range, 60~1175), respectively. Conclusion: Placement of a percutaneous metallic stent is an effective and safe method for palliation of patients with hilar cholangiocarcinoma.

• Polymer(Korea)
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• v.36 no.2
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• pp.163-168
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• 2012

Recently, along with technology development of endoscopic equipment, the stent technology has been developed for the convenience of operation, shortening of recovery times, and reduction of patient's pain. In this study, paclitaxel-eluting metal stents for treatment of biliary benign stenosis were developed through an electrospray-coating method. Polyether-based polyurethane (PELLETHANE 2363-80AE$^{(R)}$)) and paclitaxel were coated onto the surface of a metallic stent and Pluronic F127 was used as an additive. As a result, physicochemical characterization of paclitaxel via SEM, FTIR, contact angle and XRD techniques revealed the information of solid state of paclitaxel-loaded PU film. The in vitro release profile showed a slower release rate with a higher content of paclitaxel.

• The Korean Journal of Pancreas and Biliary Tract
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• v.22 no.4
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• pp.165-171
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• 2017

Background/Aim: There is little data on whether plastic stents with a larger diameter are patent for longer than small stents in patients with bile duct cancer. The aim of this study was to compare the stent survival between 7-French (Fr) and 10-Fr plastic stents and evaluate the factors affecting stent survival. Methods: Patients with biliary obstruction due to biliary tract cancer were enrolled at Yonsei University Wonju College of Medicine from January 2010 to October 2014. Results: A total of 215 patients (7-Fr:10-Fr = 89:126 patients) were retrospectively enrolled. The primary tumor sites were common bile duct (n = 111), hilar (n = 45), and ampulla of Vater (n = 59). Rates of stent migration and stent obstruction were not different between the two groups. The median duration of stent survival was 3.3 months in the 7-Fr group and 5.9 months in the 10-Fr group (p = 0.543). The diameter of the stent did not have an effect on stent survival (hazard ratio 1.11, 95% confidence interval 0.71-1.73, p = 0.649). Conclusions: 7-Fr and 10-Fr stents have similar rates of stent migration and stent obstruction. The stent survival of 7-Fr was not inferior to 10-Fr stents in the management of biliary tract cancer.

• Journal of the Korean Society of Radiology
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• v.84 no.6
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• pp.1350-1360
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• 2023

Purpose To evaluate the factors that predict symptomatic dislodgement of a percutaneous transhepatic biliary drainage (PTBD) catheter in patients with malignant biliary obstruction. Materials and Methods This retrospective study included 572 patients with malignant biliary obstruction who underwent 733 PTBD catheter insertions between January 2010 and February 2015. The duration of catheter placement, approach site, location of the catheter tip, insertion angle, presence of a closed-loop pigtail, and tube diameter were evaluated. Results During the follow-up period, 224 PTBD catheter dislodgements (30.56%) were observed in 157 patients. Among them, 146 (19.92%) were symptomatic. The mean duration from catheter insertion until dislodgement was 32 days (range: 1-233 days). Male (odds ratio [OR]: 1.636, 95% confidence interval [CI]: 1.131-2.367, p = 0.009), right-sided approach (OR: 1.567, 95% CI: 1.080-2.274, p = 0.018), increased insertion angle (OR: 1.015, 95% CI: 1.005-1.026, p = 0.005), and incomplete closed-loop pigtail formation (OR: 1.672, 95% CI: 1.098-2.545, p = 0.016) were independent factors predictive of symptomatic dislodgement of a PTBD catheter. Conclusion Factors predictive of symptomatic catheter dislodgement included male sex, a right-sided approach, increased insertion angle, and incomplete closed-loop pigtail formation.

• Journal of Digestive Cancer Research
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• v.1 no.1
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• pp.36-42
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• 2013

Background/Aims: Gemcitabine is regarded as a reference regimen for advanced pancreatic cancer and shows relatively safe toxicity profiles compared with other cytotoxic agents. However, many oncologists are appeared to be still reluctant to treat elderly pancreatic cancer patients with cytotoxic chemotherapy because of predicted low response rate and potential adverse events. Methods: All patients who were received gemcitabine based chemotherapy between 2007 and 2010 were identified and clinical, laboratory, radiographic data were retrospectively reviewed. Patients were divided into two groups based on their ages: less than 65, and equal or more than 65 years old. Gemcitabine, at a dose of 1,000 mg per square meter of body surface area, was administered by intravenously over 30 minutes weekly for 3 weeks followed by 1 week rest, alone or along with other chemotherapeutic agents including cisplatin, capecitabine and erlotinib. Results: A total of 61 patients were identified and all patients were not eligible to receive operation because of advanced stage at diagnosis. Twenty three patients (37.7%) were equal or more than 65 year of age. Mean age was 56 years old and 71 years old in each group. Laboratory data including CA 19-9 were not significantly different. More gemcitabine monotherapy was delivered (56.5% vs. 26.3%, p=0.029) and less second or third line therapy was adminis- tered (17.4% vs. 50.0%, p=0.014) in elderly group. Cholangitis occurred and stent placement were performed similarly in both groups. Conclusion: Gemcitabine based chemotherapy can be administered safely to elderly pancreatic cancer patients and comparable response rate and progression free survival can be expected as young patients.