Does potassium citrate administration change the type and composition of encrusted material on Double-J stent compared to primary stone?

PURPOSE: To evaluate the effect of potassium citrate administration on the composition of encrusted material on the ureteral stent after Double-J insertion. METHODS: We designed a randomized clinical trial for our study; 65 patients that underwent transurethral lithotripsy and Double-J stent insertion were included in the study after informed consent and divided into two groups. In the first group (33 patients) potassium citrate was prescribed after surgery till stent removal and the second group (32 patients) followed without prescribing this medication. After stent removal, encrusted materials on removed stents were analyzed then the type and composition of encrusted material compared with the primary stone that was removed. RESULTS: Our results revealed that the type and composition of primary stone and encrusted stone were similar in patients that do not receive potassium citrate (p-value of 0.073, 0.251 and 0.944 for calcium oxalate, uric acid, and calcium phosphate respectively). In patients that taking potassium citrate rate of calcium oxalate (p-value < 0.001) and uric acid (p-value < 0.001) material on encrusted stent significantly decreased compared with the non-intervention group. CONCLUSION: Results of this study revealed that taking of potassium citrate after ureteral stent insertion significantly decreases the formation of calcium oxalate and uric acid encrusted material on Double-J stent so it could be recommended for prevention of stent encrustation in patients that primary stone analysis are calcium oxalate and uric acid stone.

Covered vs bare stent for distal malignant biliary obstruction due to primary common biliary cancer.

ABSTRACT: This study was designed as a means of comparing the clinical efficacy and long-term outcomes of covered vs bare stent insertion as a treatment for distal malignant biliary obstruction (DMBO) caused by primary common biliary cancer (PCBC).This retrospective study was designed using data collected between January 2012 and December 2019 to assess the short- and long-term outcomes in patients with DMBO caused by PCBC treated by inserting either bare or covered stents were compared.Ninety two patients with DMBO caused by PCBC were divided between bare (n = 51) or covered (n = 41) stent groups. Technical success rates in both groups were 100%. Clinical success of bare vs covered stent use were 96.1% and 97.6% (P = 1.00). Stent dysfunction was seen in 17 and 6 patients in the bare and covered stent groups, respectively (P = .04). The median stent patency for bare and covered stents was 177 and 195 days, respectively (P = .51). The median survival was 188 and 200 days in the bare and covered stent groups, respectively (P = .85).For patients with DMBO caused by PCBC, using bare vs covered stents yields similar clinical efficacy and long term outcomes.

Esophageal metal stent for malignant obstruction after prior radiotherapy.

The association between severe adverse events (SAEs) and prior radiotherapy or stent type remains controversial. Patients with esophageal or esophagogastric junctional cancer who underwent stent placement (2005-2019) were enrolled in this retrospective study conducted at a tertiary cancer institute in Japan. The exclusion criteria were follow-up period of < 1 month and insufficient data on stent type or cancer characteristics. We used Mann-Whitney's U test for quantitative data and Fisher's exact test for categorical data. Multivariate analysis was performed using a logistic regression model. 107 stents were placed. Low radial-force stents (L group) were used in 51 procedures and high radial-force stents (H group) in 56 procedures. SAEs developed after nine procedures, the median interval from stent placement being 6 days (range, 1-141 days). SAEs occurred more frequently in the H (14%: 8/56) than in the L group (2%: 1/51) (P = 0.03). In patients who had undergone prior radiotherapy, SAEs were more frequent in the H (36%: 4/11) than in the L group (0%: 0/13) (P = 0.03). Re-obstruction and migration occurred after 16 and three procedures, respectively; these rates did not differ significantly between groups (P = 0.59, P = 1, respectively). Low radial-force stents may reduce the risk of SAEs after esophageal stenting.

[Influence of traditional double-J stent versus Polaris loop stent on the quality of life and erectile function of young and middle-aged men after ureteral laser lithotripsy].

OBJECTIVE: To investigate the impact of two different ureteral stents on the quality of life and erectile function of young and middle-aged men after ureteral laser lithotripsy. METHODS: A total of 118 male patients aged 22－45 years underwent ureteral laser lithotripsy followed by indwelling of the traditional double-J stent (the DJS group, n = 60) or Polaris loop stent (the PLS group, n = 58). We obtained the general information, intra- and post-operative clinical data, and scores on QOL, IPSS, Visual Analogue Scale (VAS) and IIEF, and compared them between the two groups of patients. RESULTS: There were no statistically significant differences in the body mass index, height, stone diameter, hydronephrosis degree, operation time, intra-operative adverse events, or post-operative stenting time between the two groups of patients. The PLS outperformed the DJS group in such clinical indexes as inflammation markers, lower urinary tract symptoms (LUTS), backache at urination, and QOL, IPSS and VAS scores during stenting at 4 weeks after operation(P < 0.05). The IIEF scores of the PLS and DJS groups were 8.44 ± 2.10 vs 12.50 ± 1.78 (P = 0.003) at 2 weeks, 8.65 ± 1.90 vs 13.42 ± 1.88 (P = 0.002) at 4 weeks, and 13.57 ± 1.01 vs 17.38 ± 2.47 (P = 0.003) at 6 weeks after operation, with no statistically significant difference between the two groups at 8 weeks. CONCLUSIONS: Ureteral stenting affects the quality of life and erectile function of young and middle-aged male patients after ureteral laser lithotripsy. The Polaris loop stent affects less the quality of life and erectile function of the patients than the traditional double-J stent during postoperative stenting.

Anatomic Suitability for Branched Thoracic Endovascular Repair in Patients with Aortic Arch Pathological Features.

Background Endovascular repair has become a viable alternative for aortic pathological features, including those located within the aortic arch. We investigated the anatomic suitability for branched thoracic endovascular repair in patients previously treated with conventional open surgery for aortic arch pathological features. Methods and Results Patients who underwent open surgery for aortic arch pathological features at our institution between 2000 and 2018 were included. Anatomic suitability was determined by strict compliance with the anatomic criteria within manufacturers' instructions for use for each of the following branched thoracic stent grafts: Relay Plus Double-Branched (Terumo-Aortic), TAG Thoracic Branch Endoprosthesis (W.L. Gore & Associates), Zenith Arch Branched Device (Cook-Medical), and Nexus Stent Graft System (Endospan Ltd/Jotec GmbH). Computed tomography angiography images were analyzed with outer luminal line measurements. A total of 377 patients (mean age, 64±14 years; 64% men) were identified, 153 of whom had suitable computed tomography angiography images for measurements. In total, 59 patients (15.6% of the total cohort and 38.6% of the measured cohort) were eligible for endovascular repair using at least one of the devices. Device suitability was 30.9% for thoracic aneurysms, 4.6% for type A dissections, 62.5% for type B dissections, and 28.6% for other pathological features. Conclusions The anatomic suitability for endovascular repair of all aortic arch pathological features was modest. The highest suitability rates were observed for thoracic aneurysms and for type B dissections, of which repair included part of the aortic arch. We suggest endovascular repair of arch pathological features should be reserved for high-volume centers with experience in endovascular arch repair.

Long-Term Results After Drug-Eluting Versus Bare-Metal Stent Implantation in Saphenous Vein Grafts: Randomized Controlled Trial.

Background Efficacy data on drug-eluting stents (DES) versus bare-metal stents (BMS) in saphenous vein grafts are controversial. We aimed to compare DES with BMS among patients undergoing saphenous vein grafts intervention regarding long-term outcome. Methods and Results In this multinational trial, patients were randomized to paclitaxel-eluting or BMS. The primary end point was major adverse cardiac events (cardiac death, nonfatal myocardial infarction, and target-vessel revascularization at 1 year. Secondary end points included major adverse cardiac events and its individual components at 5-year follow-up. One hundred seventy-three patients were included in the trial (89 DES versus 84 BMS). One-year major adverse cardiac event rates were lower in DES compared with BMS (2.2% versus 16.0%, hazard ratio, 0.14; 95% CI, 0.03-0.64, P=0.01), which was mainly driven by a reduction of subsequent myocardial infarctions and need for target-vessel revascularization. Five-year major adverse cardiac event rates remained lower in the DES compared with the BMS arm (35.5% versus 56.1%, hazard ratio, 0.40; 95% CI, 0.23-0.68, P<0.001). A landmark-analysis from 1 to 5 years revealed a persistent benefit of DES over BMS (hazard ratio, 0.33; 95% CI, 0.13-0.74, P=0.007) in terms of target-vessel revascularization. More patients in the BMS group underwent multiple target-vessel revascularization procedures throughout the study period compared with the DES group (DES 1.1% [n=1] versus BMS 9.5% [n=8], P=0.013). Enrollment was stopped before the target sample size of 240 patients was reached. Conclusions In this randomized controlled trial with prospective long-term follow-up of up to 5 years, DES showed a better efficacy than BMS with sustained benefits over time. DES may be the preferred strategy in this patient population. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT00595647.

Mechanical and Pharmacological Revascularization Strategies for Prevention of Microvascular Dysfunction in ST-Segment Elevation Myocardial Infarction: Analysis from Index of Microcirculatory Resistance Registry Data.

OBJECTIVES: We aimed to identify mechanical and pharmacological revascularization strategies correlated with the index of microcirculatory resistance (IMR) in ST-elevation myocardial infarction (STEMI) patients. BACKGROUND: Microvascular dysfunction (MVD) after STEMI is correlated with infarct size and poor long-term prognosis, and the IMR is a useful analytical method for the quantitative assessment of MVD. However, therapeutic strategies that can reliably reduce MVD remain uncertain. METHODS: Patients with STEMI who underwent primary percutaneous coronary intervention (PCI) were enrolled. The IMR was measured with a pressure sensor/thermistor-tipped guidewire immediately after primary PCI. High IMR was defined as values ≥66th percentile of IMR in enrolled patients (IMR > 30.9 IU). RESULTS: A total of 160 STEMI patients were analyzed (high IMR = 54 patients). Clinical factors for Killip class (P=0.006), delayed hospitalization from symptom onset (P=0.004), peak troponin-I level (P=0.042), and multivessel disease (P=0.003) were associated with high IMR. Achieving final thrombolysis in myocardial infarction myocardial perfusion grade 3 tended to be associated with low IMR (P=0.119), whereas the presence of distal embolization was significantly associated with high IMR (P=0.034). In terms of therapeutic strategies that involved adjusting clinical and angiographic factors associated with IMR, preloading of third-generation P2Y12 inhibitors correlated with reducing IMR value (ß = -10.30, P < 0.001). Mechanical therapeutic strategies including stent diameter/length, preballoon dilatation, direct stenting, and thrombectomy were not associated with low IMR value (all P > 0.05), and postballoon dilatation was associated with high IMR (ß = 8.30, P=0.020). CONCLUSIONS: In our study, mechanical strategies were suboptimal in achieving myocardial salvage. Preloading of third-generation P2Y12 inhibitors revealed decreased IMR value, indicative of MVD prevention.

Retrospective Comparative Study of Side-by-Side and Stent-in-Stent Metal Stent Placement for Hilar Malignant Biliary Obstruction.

BACKGROUND: In patients with unresectable hilar malignant biliary obstruction (MBO), bilateral metal stent placement is recommended. However, treatment selection between partially stent-in-stent (SIS) and side-by-side (SBS) methods is still controversial. STUDY: Clinical outcomes of bilateral metal stent placement by SBS and SIS methods for hilar MBO were retrospectively studied in four Japanese centers. While large-cell-type uncovered metal stents were placed above the papilla in SIS, braided-type uncovered metal stents were placed across the papilla in SBS. RESULTS: A total of 64 patients with hilar MBO (40 SIS and 24 SBS) were included in the analysis. Technical success rate was 100% in SIS and 96% in SBS. Functional success rate was 93% in SIS and 96% in SBS. Early adverse event rates were higher in SBS (46%) than in SIS (23%), though not statistically significant (P = 0.09). Post-procedure pancreatitis was exclusively observed in SBS group (29%). Recurrent biliary obstruction rates were 48% and 43%, and the median time to recurrent biliary obstruction was 169 and 205 days in SIS and SBS, respectively. CONCLUSIONS: Other than a trend to higher adverse event rates including post-procedure pancreatitis in SBS, clinical outcomes of SIS and SBS methods were comparable in patients with unresectable hilar MBO.

Percutaneous stenting and chemotherapy for unresectable pancreatic cancer: Comparison of irradiation stents vs conventional metal stents.

OBJECTIVES: Percutaneous stenting is a palliative method to relieve obstructive jaundice caused by unresectable pancreatic carcinoma. In this study, we aimed to compare the safety and efficacy of irradiation stents and conventional metal stents. METHODS: A total of 32 patients who received irradiation stents or conventional metal stents to treat obstructive jaundice caused by locally advanced pancreatic cancer were included in this retrospective study. Chemotherapy using gemcitabine was performed after jaundice subsided. Stent patency, technical success, survival, and complications were compared between groups. RESULTS: Seventeen patients were enrolled in the irradiation stent group (ISG), and 15 patients were enrolled in the uncovered stent group (USG). Median and mean stent patency time were 9.8 months (95% CI, 7.682-11.981) and 9.506 months (95% CI, 8.0-11.012) in the ISG, respectively, vs 8.8 months (95% CI, 6.528-11.072) and 7.62 months (95% CI, 5.917-9.323) in the USG, respectively (P = 0.019). Median and mean overall survival were 10.4 months (95% CI, 8.383-12.417) and 9.953 months (95% CI, 8.408-11.498), respectively, in the ISG vs 9.7 months (95% CI, 7.901-11.499) and 8.14 months (95% CI, 6.44-9.84), respectively, in the USG (P = 0.027). CONCLUSIONS: Irradiation stents extend stent patency and overall survival compared with conventional biliary stents for the treatment of pancreatic carcinoma complicated by obstructive jaundice. Irradiation stents combined with chemotherapy may be a better choice for the treatment of obstructive jaundice caused by unresectable pancreatic carcinoma.

Interwoven Nitinol Stents versus Drug Eluting Stents in the Femoro-Popliteal Segment: A Propensity Matched Analysis.

BACKGROUND: Percutaneous transluminal angioplasty (PTA) is a common procedure in patients with peripheral arterial disease (PAD) affecting the femoropopliteal segment (F-P). Biomimetic nitinol stents (Supera peripheral stent, SPS) and drug eluting stents (DES) were designed to improve the longevity of F-P PTA; however, their performance has not been compared in a pragmatic setting, taking atherosclerotic plaque characteristics into account. METHODS: Overall, 296 consecutive patients (mean age: 73 y, SD: 11 y, 65% male, 68% with chronic limb threatening ischaemia) who underwent F-P PTA using SPS or DES between 2013 and 2018 were identified from a prospectively maintained institutional database. Patient and plaque characteristics, including F-P plaque characterisation based on computed tomography, were collected; 121 case matched pairs were created using a propensity score based on patient and plaque data. RESULTS: During the median two year follow up, 28% of the cohort (32% SPS vs. 24% DES, p = .07) developed target lesion restenosis (TLR) > 50%. Among the 121 case matched pairs of patients, those with SPS vs. DES were not significantly more likely to develop TLR >50% (31% vs. 27%, p = .34), or stent occlusion (13% vs. 12%, p = .85 - secondary patency rate 87% vs. 88%), have a major amputation (10% vs. 6%, p = .16), require re-intervention (14% vs. 9%, p = .12), or die (7% vs.4%, p = .31). Plaque calcification did not predict restenosis or occlusion in either stent group, both in the matched and non matched populations. Multivariable analysis adjusted for patient and plaque characteristics revealed that the main predictors of restenosis >50% at two years were female sex [odds ratio (OR): 2.05, p = .01], hypertension (OR: 2.10, p = .04) and previous F-P occlusion (OR: 1.35, p = .04). CONCLUSION: Medium term results following F-P PTA with either SPS or DES are comparable, regardless of plaque calcification and patient characteristics.

A Review of Self-Expanding Esophageal Stents for the Palliation Therapy of Inoperable Esophageal Malignancies.

Esophageal cancer is a very deadly disease, killing more than 15,000 people in the United States annually. Almost 400,000 new cases happen in the worldwide every year. More than 50% esophageal cancer patients are diagnosed at an advanced stage when they need an esophageal stent to open the blocked esophagus for feeding and drinking. Esophageal stents have evolved in stages over the years. Current clinically used stents commonly include stainless steel or nitinol self-expandable metallic stent (SEMS) and self-expandable plastic stent (SEPS). There are many choices of different types of stents and sizes, with fierce competition among manufacturers. However, current stent technology, whether uncovered, partially covered, fully covered SEMS or SEPS, has their own advantages to solve the dysphagia, stricture, and fistula problems, but they also cause some clinical complications. The ideal stent remains elusive. New 3D printing technique may bring new promising potential to manufacturing personalized esophageal stents. Drug-eluting stents could be the new avenue to do more than just pry open a stricture or cover a defect in the esophageal lumen, a possibility of proving local anticancer therapy simultaneously. Additionally, the lack of esophageal cancer animal models also hinders the progress of stent development. This paper reviews these topics for a comprehensive understanding of this field. In a conclusion, the ultimate goal of the future esophageal stent would have multifunction to treat the underlying conditions and restore esophageal function to near normal.

Interventional Bronchoscopy for the Treatment of Malignant Central Airway Stenosis: An Expert Recommendation for China.

Malignant central airway stenosis refers to airway stenosis caused by primary or metastatic malignant tumors which may lead to different levels of dyspnea or asphyxia in patients. With the rapid development of interventional pulmonology, therapeutic bronchoscopy has become one of the main methods for the diagnosis and treatment of malignant central airway stenosis. However, the level of diagnosis and treatment of respiratory intervention techniques in China is uneven at present, the treatment methods are not uniform, the treatment effects vary greatly, and some treatments even lead to serious complications. The interventional treatment technology for malignant central airway stenosis in China needs to be standardized. Therefore, the relevant experts of the Beijing Health Promotion Association Respiratory and Oncology Intervention and Treatment Alliance have formulated this consensus after several rounds of full discussion.

Endoscopic, Single-Session Management of Encrusted, Forgotten Ureteral Stents.

Background and Objectives: Remained or forgotten ureteral double-J stents may cause serious complications. Removing of an encrusted, forgotten stent can be challenging. We present our experience with heavily encrusted ureteral stents and discuss the endourologic treatment options as well as their effectivity. Materials and Methods: Eleven men and six women (mean 48.58 ± 14.48 years of age) with 18 encrusted forgotten stents (mean 16.4 ± 13.25 months of indwelling) were treated at our clinic. All patients underwent the operation after negative urine cultures were obtained. Their medical records were retrospectively reviewed and analyzed in terms of number of interventions required to remove the stent, operation time, complications, hospital stay and stone-free rate. Results: According to the Forgotten-Encrusted-Calcified (FECal) classification, the most common form of stent encrustation was grade III (64.7%) and 17.6% of the stents were fragmented. Four of 17 patients were initially treated with extracorporeal shock-wave lithotripsy. The patients required a mean of two endoscopic interventions for removing the encrusted stent and all stents were removed endoscopically in a single session. The mean operating time was 63.3 ± 41.8 minutes. Cystolithotripsy followed by ureteroscopy was the most common intervention (41.1%). Of the 17 patients, peroperative and postoperative complications were Clavien grade I in two, grade II in two and grade IIIb in one. The mean hospital stay was 1.3 ± 0.99 days. All patients were stone-free after a month of stent removal. Conclusions: The endourological removal of the encrusted forgotten stents in a single session is feasible and effective with a minimal morbidity. The treatment strategy should be to minimize the number of interventions.

Metallic Endobronchial Stents: A Contemporary Resurrection.

Airway stenting has been practiced for several decades. It is one of the most common procedures performed by interventional pulmonologists. Typically, these stents are implanted to maintain the tubular patency of the tracheobronchial tree. They are only considered as a temporizing measure, or when a surgical option cannot be pursued. Through the past few decades, a number of metallic airway stents have been introduced into the market. First generation stents were comparatively simplistic and crafted from stainless steel. The latest generation of metallic airway stents are hybrid in nature and constructed with complex alloys. As airway stenting become more widely practiced, concerns arose regarding their safety. However, with improved understanding of stent-airway interactions, advancements in biomedical engineering, and a larger emphasis on post procedural care, the use of metallic endobronchial stents has been resurrected. We present the history, technological advancement, and contemporary indications of metallic airway stents.

[Vascular stents: Approaches used to increase their clinical efficacy]. / Stenty sosudov: podkhody, ispol'zuemye dlia povysheniia ikh klinicheskoi éffektivnosti.

Using stents for endovascular restoration of blood flow made a revolution in vascular surgery, however, despite numerous variants of stents presented on the pharmacological market, there are no stents which would completely solve the problem of restenosis in the area of stent placement. In order to decrease growth of the neointima of the stented portions of vessels, stents coated with cytostatic and cytotoxic agents were worked out. To optimize the rate of drug release it was suggested to apply them in a mixture with biodegradable or biostable polymers. Placement of drug-eluting stents in a combination with dual antiplatelet therapy made it possible to decrease frequency of restenosis and reocclusion of the restored vascular lumen in patients, however it did not solve the problem of the development of thromboses and neointimal hyperplasia in the remote postoperative period. The article provides an overview of various modifications of vascular stents, clinical studies of stents of various manufacturers, as well as modern developments in manufacturing polymer/drug coatings and methods of applying them onto the stent. This is followed by analyzing the contribution of coatings to clinical efficacy of stents and prospects of increasing efficacy of vascular stents.

Prospective Evaluation of Two iStent® Trabecular Stents, One iStent Supra® Suprachoroidal Stent, and Postoperative Prostaglandin in Refractory Glaucoma: 4-year Outcomes.

INTRODUCTION: This study evaluates long-term outcomes of two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin in eyes with refractory open angle glaucoma (OAG). METHODS: Prospective ongoing 5-year study of 80 eligible subjects (70 with 4-year follow-up) with OAG and IOP ≥ 18 mmHg after prior trabeculectomy and while taking 1-3 glaucoma medications. Subjects received two iStent® trabecular micro-bypass stents, one iStent Supra® suprachoroidal stent, and postoperative travoprost. Postoperative IOP was measured with medication and annually following medication washouts. Performance was measured by the proportion of eyes with ≥ 20% IOP reduction on one medication (the protocol-specified prostaglandin) versus preoperative medicated IOP (primary outcome); and the proportion of eyes with postoperative IOP ≤ 15 and ≤ 18 mmHg on one medication (secondary outcome). Additional clinical and safety data included medications, visual field, pachymetry, gonioscopy, adverse events, visual acuity, and slit-lamp and fundus examinations. RESULTS: Preoperatively, mean medicated IOP was 22.0 ± 3.1 mmHg on 1.2 ± 0.4 medications, and mean unmedicated IOP was 26.4 ± 2.4 mmHg. Postoperatively, among eyes without later cataract surgery, mean medicated IOP at all visits through 48 months was ≤ 13.7 mmHg (≥ 37% reduction), and annual unmedicated IOP was ≤ 18.4 mmHg (reductions of ≥ 30% vs. preoperative unmedicated IOP and ≥ 16% vs. preoperative medicated IOP). At all postoperative visits among eyes without additional surgery or medication, ≥ 91% of eyes had ≥ 20% IOP reduction on one medication versus preoperative medicated IOP. At month 48, 97 and 98% of eyes achieved IOP ≤ 15 and ≤ 18 mmHg, respectively, on one medication. Six eyes required additional medication, no eyes required additional glaucoma surgery, and safety measurements were favorable throughout follow-up. CONCLUSION: IOP control was achieved safely with two trabecular micro-bypass stents, one suprachoroidal stent, and postoperative prostaglandin. This microinvasive, ab interno approach introduces a possible new treatment option for refractory disease. TRIAL REGISTRATION: NCT01456390. FUNDING: Glaukos Corporation.

Metallic Ureteric Stents in Malignant Ureteric Obstruction: A Systematic Review.

The effectiveness of metallic stents in the management of malignant ureteric obstruction is unclear. This systematic review evaluates the use of 4 commercially available metallic stents (Resonance, Memokath 051, Uventa, and Allium URS). Twenty-one studies met eligibility criteria. Overall success rates ranged from 88% for the Allium stent to 65% for Memokath 051. Resonance demonstrated the lowest migration rate (1%). Uventa had the lowest obstruction rate (6%). Metallic ureteric stents offer a viable alternative in the management of malignant ureteric obstruction. Further high quality studies are required to assess cost effectiveness and refine specific indications based on etiology and level of the ureteric obstruction.

Soft surface irregularity of malignant perihilar biliary strictures in cholangiography as a risk factor for early dysfunction of multiple metal stents.

BACKGROUND: Multiple metal stents (multi-MS) in the perihilar bile duct often develop dysfunction in an unexpectedly short period. AIMS: This study is aimed to identify the risk factors for shorter patency of multi-MS. METHODS: Of 97 patients who underwent multi-MS placement, 68 patients were followed-up for >28 days were retrospectively analyzed. Univariate analyses with the log-rank test was performed on 20 factors, including two newly defined classifications of cholangiography: the R classification, which classifies the rough image (localized type [R1] or spreading type [R2]); and the S classification, which classifies the surface texture (soft irregularity [S1], solid irregularity [S2], or smooth [S3]). RESULTS: Stent dysfunction occurred in 36 patients (53%) (median time, 209 days). Type S1 was a significant risk factor for short stent patency (median, 100 days in S1 [n=18]; 231 in S2 [n=38]; 356 in S3 [n=12], p<0.0001). On multivariate analysis, type S1 was again the only independent factor among the six factors (HR 4.8, p<0.001). CONCLUSION: Soft surface irregularity of the perihilar malignancy in cholangiography was found to be a significant risk factor for a shorter time to dysfunction of multi-MS.