3-Year Outcomes After 2-Stent With Provisional Stenting for Complex Bifurcation Lesions Defined by DEFINITION Criteria.

BACKGROUND: The multicenter and randomized DEFINITION II (Two-Stent vs Provisional Stenting Techniques for Patients With Complex Coronary Bifurcation Lesions) trial showed less 1-year target lesion failure (TLF) after a 2-stent approach for complex coronary bifurcation lesions compared with provisional stenting (PS). The authors report the 3-year clinical outcome of the DEFINITION II trial. OBJECTIVES: The aim of the present study was to investigate the difference in TLF at 3 years after a planned 2-stent approach vs PS for complex coronary bifurcation lesions stratified by DEFINITION (Definitions and Impact of Complex Bifurcation Lesions on Clinical Outcomes After Percutaneous Coronary Intervention Using Drug-Eluting Stents) criteria. METHODS: A total of 653 patients with complex coronary bifurcation lesions were randomly assigned to either the 2-stent group or the PS group in the DEFINITION II trial and were followed for 3 years. The primary endpoint was the occurrence of TLF at 3 years. Stent thrombosis was the safety endpoint. RESULTS: At 3 years, TLF had occurred in 52 patients (16.0%) in the PS group and in 34 (10.4%) patients in the 2-stent group (HR: 0.63; 95% CI: 0.41-0.97; P = 0.035), driven mainly by increased target vessel myocardial infarction (8.0% vs 3.7%; HR: 0.45; 95% CI: 0.23-0.89; P = 0.022) and target lesion revascularization (8.3% vs 4.3%; HR: 0.50; 95% CI: 0.26-0.96; P = 0.038). There was no difference in TLF between the 2 groups between year 1 and year 3. CONCLUSIONS: For patients with complex coronary bifurcations who reach 1-year postprocedure without experiencing endpoint events, there is still a risk for future events. The type of procedure performed initially is no longer a future event risk determinant. (Two-Stent vs Provisional Stenting Techniques for Patients With Complex Coronary Bifurcation Lesions; NCT02284750).

Comparison Between Lumen-Apposing Metal Stents and Plastic Stents in Endoscopic Ultrasound-Guided Drainage of Pancreatic Fluid Collection: A Meta-analysis and Systematic Review.

OBJECTIVES: This study aimed to explore efficacy and safety between LAMSs (lumen-apposing metal stents) and DPPSs (double-pigtail plastic stents) in endoscopic ultrasound-guided drainage for pancreatic fluid collections. METHODS: Electronic databases were searched to identify relevant studies published until July 20, 2020. RESULTS: Fifteen studies were identified in this study. Endoscopic ultrasound-guided drainage with LAMS has higher clinical success (90.01% vs 82.56%) (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.79-3.33; P < 0.00001), less recurrence (OR, 0.44; 95% CI, 0.29-0.68; P = 0.0002), and fewer additional interventions (OR, 0.34; 95% CI, 0.211-0.55; P < 0.001). There was no significant difference between LAMS and DPPS in technical success (97.45% vs 97.38%) (OR, 0.92; 95% CI, 0.50-1.70; P = 0.80), adverse events (OR, 0.92; 95% CI, 0.41-2.09; P = 0.84), stent-related adverse events (OR, 0.78; 95% CI, 0.39-1.54; P = 0.47), and bleeding (OR, 1.47; 95% CI, 0.57-3.28; P = 0.42). Lumen-apposing metal stents have slightly more perforations (OR, 7.10; 95% CI, 1.22-41.30; P = 0.03) in studies of walled-off necrosis. CONCLUSIONS: Lumen-apposing metal stents have the advantage of higher clinical success, less recurrence, and fewer additional interventions. However, LAMS may increase perforation for walled-off necrosis.

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.

Long-Term Clinical Outcomes of Unprotected Left Main Percutaneous Coronary Intervention: A Large Single-Centre Experience.

AIMS: This study sought to report the 10-year clinical outcomes of patients who underwent unprotected left main (LM) percutaneous coronary intervention (PCI) in a large centre. METHODS AND RESULTS: A total of 913 consecutive patients who underwent unprotected LM PCI from January 2004 to December 2008 at Fu Wai Hospital were retrospectively analysed; the mean age was 60.0 ± 10.9 years, females accounted for 22% of patients, diabetes was present in 27.7% of patients, and an LM bifurcation lesion occurred in 82.9% of patients. During the median follow-up of 9.7 years, major adverse cardiac or cerebrovascular events (MACCEs) occurred in 25.6% (234) of patients, and the rates of all-cause death, myocardial infarction, and stroke were 14.9%, 11.0%, and 7.1%, respectively. Cardiac death occurred in only 7.9% of patients. The estimated event rate was 41.9% for death/myocardial infarction/any revascularization and 45.9% for death/MI/stroke/any revascularization. Definite/probable stent thrombosis occurred in 4.3% (39) of patients. According to the subgroup analysis, IVUS-guided PCI was associated with less long-term MACCEs. Further multivariate analysis identified that age and LVEF<40% were the only independent predictors for 10-year death. Age, LVEF<40%, creatinine clearance, and incomplete revascularization were independent predictors for death/MI, while a two-stent strategy, diabetes, a transradial approach, and the use of bare metal stents (BMSs) or first-generation drug-eluting stents (DESs) were not. CONCLUSIONS: Unprotected LM PCI in a large cohort of consecutive patients in a single large centre demonstrated favourable long-term outcomes up to 10 years even with the use of BMSs and first-generation of DESs.

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.

Characteristics of recurrent in-stent restenosis after second- and third-generation drug-eluting stent implantation.

BACKGROUND: In second- and third-generation drug-eluting stent (DES) era, in-stent restenosis (ISR) is not commonly seen. However, a few patients still need repeat revascularizations for recurrent ISR even after second- and third-generation DES implantation. METHODS: From January 2012 to March 2017, 2339 lesions underwent second- and third-generation DES (Nobori, Promus Element, Resolute Integrity, Xience, Ultimaster and Synergy) implantation, of which 95 lesions (4.1%) underwent revascularization for first ISR. All lesions were divided into two groups of recurrent ISR group and non-recurrent ISR group. After successful optical coherence tomography (OCT) guided revascularization for all lesions, we investigated characteristics of recurrent ISR, and 2 years follow-up were completed. RESULTS: The mean age was 70.8 ± 11.7 years, and 73.2% were males. Among 56 DES-ISR lesions which were assessed by OCT, recurrent ISR was seen in 33.9% (N = 19) at 2 years follow-up after revascularization for first ISR. Serum low-density lipoprotein-cholesterol (LDL-C) level was higher in recurrent ISR group compared with non-recurrent ISR group (114.1 ± 53.9 mg/dl vs. 90.9 ± 27.8 mg/dl, P = 0.04) and heterogeneous tissue pattern was more frequently found in recurrent ISR group compared with non-recurrent ISR group (63.2% vs. 27.0%, P = 0.03). Multivariate analysis identified a heterogeneous tissue pattern (odds ratio 3.71; 95% confidence interval 1.09-12.59; P = 0.03) as an independent predictor of recurrent restenosis. CONCLUSION: Recurrent ISR of second- and third-generation DES was associated with heterogeneous tissue pattern of first ISR, and high LDL-C level was associated with recurrence.

[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.

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.

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.

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.

Clinical Outcomes of Drug-Eluting versus Bare-Metal In-Stent Restenosis after the Treatment of Drug-Eluting Stent or Drug-Eluting Balloon: A Systematic Review and Meta-Analysis.

BACKGROUND: Although drug-eluting stents (DES) have reduced the rates of in-stent restenosis (ISR) compared with bare-metal stents (BMS), DES related ISR (DES-ISR) still occurs and outcomes of DES-ISR remain unclear. The objective of this meta-analysis was to investigate the long-term clinical outcomes of patients with DES-ISR compared with patients with BMS related ISR (BMS-ISR) after the treatment of DES or drug-eluting balloon (DEB). Methods and results. We searched the literature in the main electronic databases including PUBMED, EMBASE, Cochrane Library, and Web of Science. The primary endpoints were target lesion revascularization (TLR) and target vessel revascularization (TVR). The secondary endpoints included all cause death (ACD), cardiac death (CD), myocardial infarction (MI), stent thrombosis or re-in-stent restenosis (ST/RE-ISR), and major adverse cardiovascular events (MACEs). A total of 19 studies with 6256 participants were finally included in this meta-analysis. Results showed that the rates of TLR (P < 0.00001), TVR (P < 0.00001), CD (P=0.02), ST/RE-ISR (P < 0.00001), and MACEs (P < 0.00001) were significantly higher in the DES-ISR group than in the BMS-ISR group. No significant differences were found between the two groups in the rates of MI (P=0.05) and ACD (P=0.21). CONCLUSIONS: Our study demonstrated that patients with DES-ISR had worse clinical outcomes at the long-term follow-up than patients with BMS-ISR after the treatment of DES or DEB, suggesting that DES and DEB may be more effective for BMS-ISR than that for DES-ISR. Positive prevention of DES-ISR is indispensable and further studies concentrating on detecting the predictors of outcomes of DES-ISR are required.

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.

Double-Kissing Nanocrush for Bifurcation Lesions: Development, Bioengineering, Fluid Dynamics, and Initial Clinical Testing.

BACKGROUND: When possible, a single-stent technique to treat coronary bifurcation disease is preferable. However, when 2 stents are required, there is scope to improve on existing techniques. The crush technique has already been improved with the introduction of double-kissing (DK) and minicrush. We sought to refine and simplify the minicrush technique, retaining its advantages while avoiding its disadvantages, by developing a DK nanocrush technique. METHODS: The DK nanocrush method allows complete lesion coverage of a bifurcation lesion without excessive metal layers. This is achieved by positioning the side branch (SB) stent with minimal protrusion into the main branch (MB), implantation of the SB stent with an undeployed balloon in the MB, immediate kissing-balloon inflation with formation of a minimal neocarina, stenting the MB, recrossing the proximal part of the SB without crossing a double metal layer, and final kissing. We demonstrate this technique with benchtop implantation, microscopic computed tomographic reconstruction, computational fluid dynamics (CFD) modelling, and clinically with the use of angiographic and intravascular imaging. RESULTS: The DK nanocrush was practically feasible and resulted in full ostial coverage. CFD analysis demonstrated minimally disturbed blood flow. The technique was successfully utilised in 9 patients with bifurcation lesions with excellent angiographic outcomes and no adverse events over 12 months. CONCLUSIONS: The DK nanocrush technique may represent the ultimate refinement of the original crush technique with a number of practical and theoretical advantages. It remains to be tested against other bifurcation techniques in prospective trials.

Stent implantation for severe pulmonary vein stenosis or occlusion secondary to atrial fibrillation ablation.

BACKGROUND: Catheter interventional treatment of pulmonary vein stenosis or occlusion (PVS/O) following radiofrequency ablation (RFA) for atrial fibrillation (AF) remains a challenging field due to lacking randomized data and there are limited data about stenting. METHODS: All patients at our center who underwent pulmonary vein stenosis (PVS) stenting for PVS/O induced by RFA were retrospectively assessed. Clinical presentation, anatomic site of stenosis and hemodynamic information, as well as follow-up data, were collected and analyzed. RESULTS: From January 2010 to June 2018, 56 patients with PVS/O secondary to RFA were treated with 113 stents. Procedural success rate was 95.8%. Pressure gradients significantly reduced (p < 0.001) and vessel caliber markedly increased (p < 0.001) in all the stenotic sites, with immediate symptoms significantly improved. The overall in-stent restenosis (ISR) rate was 21.8% after a median follow-up period of 26 months (interquartile range: 16 to 35.5 months). The incidence of ISR was higher in patients treated with stent diameter ≤ 8 mm than those with stent diameter >8 mm (HR: 3.91; 95% CI 1.74-8.81; p = 0.001). CONCLUSIONS: PVS stenting is a safe and effective procedure for PVS/O secondary to RFA. Long-term patency and good clinical outcomes are gained after bigger-diameter stent implantation.

Impact of the Balloon Inflation Time and Pattern on the Coronary Stent Expansion.

OBJECTIVES: To assess the expansion pattern of coronary stents by using different balloon inflation times and pressures. BACKGROUND: The selection of coronary stent size and its proper deployment is crucial in coronary artery interventions, having an impact on the success of the procedure and further therapy. METHODS: Ten pairs of different stents were deployed under nominal pressure using sequential (5, 5, 10, and 10 seconds of repeated inflations, thus 30 seconds of summarized time) and continuous (30 seconds) deployment pattern. After each given time-point, intraluminal stent measurements were performed by optical coherence tomography (OCT) and intravascular ultrasound (IVUS). RESULTS: Both in-stent diameters and cross-section areas (CSA) of paired stents measured by OCT at all sequential time-points were significantly smaller compared to given manufacturers charts' values (90% to 94% for diameters and 81% to 88% for CSA, p<0.05). Significant increase of in-stent diameter and CSA was observed across the step-by-step deployment pattern. In-stent lumen measurements were significantly larger when sequential deployment pattern was applied compared to continuous deployment. Additional measurements were also done for overlapping segments of stents, showing smaller in-stent measurements of the latter compared to nonoverlapping segments. Validation of OCT and IVUS measurements using a phantom metallic tube showed perfect reproducibility with OCT and overestimation with IVUS (8% for diameters and 16% for CSA). CONCLUSIONS: Stent diameter after deployment is time-dependent and not only pressure-dependent. Different stent expansion behavior, depending on the applied deployment pattern (sequential and nonsequential), was observed.

Análisis de degradación de stents metálicos en modelo de cultivo "in vitro" con células epiteliales respiratorias y fibroblastos / Degradation analysis for metal stents in an in vitro cell culture model with respiratory epithelial cells and fibroblasts

Objetivo: investigar la posible degradación de stents metálicos tras co-cultivo con células respiratorias in vitro. Método: durante 21 días se han co-cultivado con la línea CRL-4011 (epitelial) y MRC-5 (fibroblastos) tres tipos de stents: Wallstent(R) (aleación de cobalto-cromo-níquel y molibdeno), Zilver PTX(R) y Zilver Flex(R) (nitinol, aleación de níquel-titanio, con y sin liberación de paclitaxel, respectivamente). Las mismas células sin stent sirvieron como control. Los sobrenadantes de los cultivos se recogieron los días 3, 9, 15 y 21, se alicuotaron y almacenaron a -800 C. Mediante espectrometría de masas (ICP/ MS) se investigaron los niveles de titanio, cromo, níquel, cobalto y molibdeno en los sobrenadantes, y también se han analizado los niveles de esos mismos elementos en el medio de cultivo original (antes de añadirlo a los cultivos celulares). Resultados: en todos los experimentos se encontraron mayores niveles de elementos metálicos en los sobrenadantes recogidos en el tercer día de cultivo, tanto de células epiteliales como de fibroblastos, con diferencias estadísticamente significativas (p<0,002). Los sobrenadantes de los cultivos de células epiteliales con Wallstent mostraron los niveles más altos de níquel y cobalto respecto a los controles (p = 0,001), y los niveles de titanio fueron más altos en los cultivos de Zilver Flex y PTX, constituidos por una aleación de níquel y titanio (p <0,001). Conclusiones: hemos detectado una rápida liberación en el sobrenadante de todos los cultivos de los elementos constitutivos de los tres stents que incluimos en los experimentos, y con niveles muy superiores a los cultivos controles

Objective: To investigate the possible degradation of metal stents after co-culture with respiratory cells in vitro. Methods: Three types of stents were co-cultured with the CRL-4011 line (epithelial) and the MRC-5 line (fibroblasts): Wallstent(R) (cobalt-chromium-nickelmolybdenum alloy), Zilver PTX(R) and Zilver Flex(R) (nitinol, nickel-titanium alloy, with and without paclitaxel release, respectively). The same stentless cells served as the control group. Culture supernatants were collected on days 3, 9, 15 and 21, aliquoted and stored at -80 ºC. The levels of titanium, chromium, nickel, cobalt and molybdenum in the supernatants were studied using inductively coupled plasma mass spectrometry (ICP-MS), and the levels of the same elements were also analyzed in the original culture medium (before adding them to the cell cultures). Results: In all experiments, higher levels of metal elements were found in the supernatants collected on the third day of culture, for both epithelial cells and fibroblasts, with statistically significant differences (p < 0.002). The supernatants of epithelial cell cultures with Wallstent showed the highest levels of nickel and cobalt in comparison to controls (p = 0.001), and titanium levels were higher in Zilver Flex and Zilver PTX cultures, consisting of a nickeltitanium alloy (p < 0.001). Conclusion: We have detected a rapid release in the supernatant of all the cultures of the constituent elements of the three stents that we included in the experiments, and with levels much higher than those of the control cultures

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.