Covered Stent Group Research Articles

Comparison of outcomes for transjugular intrahepatic portosystemic shunt creation: Viatorr versus Fluency versus a bare stent/Fluency stent combination

PurposeTo compare clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) created with the single covered-uncovered stent (Viatorr TIPS Endoprosthesis) versus covered stent (Fluency) versus a combination of covered and uncovered stent.Materials and methodsFrom May 2016 and July 2019, a total of 180 liver cirrhosis patients with recurrent variceal bleeding underwent TIPS creation with single covered-uncovered stent (n = 63) or covered stent (n = 41) or a covered and uncovered stent combination (n = 76). Shunt dysfunction, rebleeding, overt hepatic encephalopathy and mortality was estimated using the Kaplan–Meier method and compared with the log-rank test.ResultsThe difference of baseline characteristics among these three groups were not significant. The included patients had a median age of 51 years (IQR 43–61), and 101 (56.1%) were men. The 1-year and 2-year shunt dysfunction rates were 1.6% and 3.2% in the single covered-uncovered stent group, 7.3% and 7.3% in the covered stent group and 5.3% and 6.6% in the combination group, respectively. There was no significant difference among groups [Hazard Ratio (HR) (95%CI): 1 vs 2.29 (0.38 − 13.72) vs 2.10 (0.41 − 10.83); P = 0.913]. No significant differences in the incidence of all-cause rebleeding were observed between the groups at 1 year (Viatorr vs Fluency vs combination: 11.1% vs 17.1% vs 10.5%) as well as 2 years (15.9% vs 17.1% vs 11.8%), with the HR (95%CI) being 1 vs 1.27 (0.5—3.21) vs 0.74 (0.30–1.82); P = 0.475). The 1-year and 2-year incidence of overt hepatic encephalopathy were 30.2% and 30.2% in the single covered-uncovered stent group, 22.0% and 22.0% in the covered stent group and 25.0% and 25.0% in the combination group, respectively. However, there was no significant difference among these three groups (P = 0.402). In addition, there was no significant difference in the 1-year and 2-year mortality (6.3% and 7.9% vs. 4.9% and 9.8% vs. 6.6% and 9.2%, P = 0.606).ConclusionNo significant difference was observed among different stent groups. Fluency covered stent and the generic bare stent/Fluency covered stent was not an unreasonable alternative to the Viatorr stent for TIPS creation.

Covered versus bare-metal stenting of the mesenteric arteries in patients with chronic mesenteric ischaemia (CoBaGI): a multicentre, patient-blinded and investigator-blinded, randomised controlled trial

Mesenteric artery stenting with a bare-metal stent is the current treatment for atherosclerotic chronic mesenteric ischaemia. Long-term patency of bare-metal stents is unsatisfactory due to in-stent intimal hyperplasia. Use of covered stents might improve long-term patency. We aimed to compare the patency of covered stents and bare-metal stents in patients with chronic mesenteric ischaemia. We conducted a multicentre, patient-blinded and investigator-blinded, randomised controlled trial including patients with chronic mesenteric ischaemia undergoing mesenteric artery stenting. Six centres in the Netherlands participated in this study, including two national chronic mesenteric ischaemia expert centres. Patients aged 18 years or older were eligible for inclusion when an endovascular mesenteric artery revascularisation was scheduled and a consensus diagnosis of chronic mesenteric ischaemia was made by a multidisciplinary team of gastroenterologists, interventional radiologists, and vascular surgeons. Exclusion criteria were stenosis length of 25 mm or greater, stenosis caused by median arcuate ligament syndrome or vasculitis, contraindication for CT angiography, or previous target vessel revascularisation. Digital 1:1 block randomisation with block sizes of four or six and stratification by inclusion centre was used to allocate patients to undergo stenting with bare-metal stents or covered stents at the start of the procedure. Patients, physicians performing follow-up, investigators, and radiologists were masked to treatment allocation. Interventionalists performing the procedure were not masked. The primary study outcome was the primary patency of covered stents and bare-metal stents at 24 months of follow-up, evaluated in the modified intention-to-treat population, in which stents with missing data for the outcome were excluded. Loss of primary patency was defined as the performance of a re-intervention to preserve patency, or 75% or greater luminal surface area reduction of the target vessel. CT angiography was performed at 6 months, 12 months, and 24 months post intervention to assess patency. The study is registered with ClinicalTrials.gov (NCT02428582) and is complete. Between April 6, 2015, and March 11, 2019, 158 eligible patients underwent mesenteric artery stenting procedures, of whom 94 patients (with 128 stents) provided consent and were included in the study. 47 patients (62 stents) were assigned to the covered stents group (median age 69·0 years [IQR 63·0-76·5], 28 [60%] female) and 47 patients (66 stents) were assigned to the bare-metal stents group (median age 70·0 years [63·5-76·5], 33 [70%] female). At 24 months, the primary patency of covered stents (42 [81%] of 52 stents) was superior to that of bare-metal stents (26 [49%] of 53; odds ratio [OR] 4·4 [95% CI 1·8-10·5]; p<0·0001). A procedure-related adverse event occurred in 17 (36%) of 47 patients in the covered stents group versus nine (19%) of 47 in the bare-metal stent group (OR 2·4 [95% CI 0·9-6·3]; p=0·065). Most adverse events were related to the access site, including haematoma (five [11%] in the covered stents group vs six [13%] in the bare-metal stents group), pseudoaneurysm (five [11%] vs two [4%]), radial artery thrombosis (one [2%] vs none), and intravascular closure device (none vs one [2%]). Six (13%) patients in the covered stent group versus one (2%) in the bare-metal stent group had procedure-related adverse events not related to the access site, including stent luxation (three [6%] vs none), major bleeding (two (4%) vs none), mesenteric artery perforation (one [2%] vs one [2%]), mesenteric artery dissection (one [2%] vs one [2%]), and death (one [2%] vs none). The findings of this trial support the use of covered stents for mesenteric artery stenting in patients with chronic mesenteric ischaemia. Atrium Maquet Getinge Group.

Outcomes of covered vs bare metal stents for the treatment of aortoiliac occlusive disease

ObjectiveWe retrospectively compared the clinical outcomes of self-expanding covered stents (CSs) and bare metal stents (BMSs) in the treatment of aortoiliac occlusive disease (AIOD) at a single center between 2016 and 2022. MethodsAll patients with AIOD receiving endovascular therapy at a single center from January 2016 to October 2022 were continuously analyzed, including patients with lesions of all classes according to the Trans-Atlantic Inter-Society Consensus II (TASC-II). Relevant clinical and baseline data were collected, and propensity score matching was performed to compare CSs and BMSs in terms of baseline characteristics, surgical factors, 30-day outcomes, 5-year primary patency, and limb salvage. The follow-up results were analyzed by Kaplan-Meier curves. Cox proportional hazard models were used to identify predictors of primary patency. ResultsA total of 209 patients with AIOD were enrolled in the study, including 135 patients (64.6%) in the CS group and 74 patients (35.4%) in the BMS group. Surgical success rates (100% vs 100%; P = 1.00), early (<30-day) mortality rates (0% vs 0%; P = 1.00), cumulative surgical complication rate (12.0% vs 8.0%; P = .891), 5-year primary patency rate (83.4% vs 86.9%; P = .330), secondary patency rate (96% vs 100%; P = .570), and limb salvage rate (100% vs 100%; P = 1.00) did not exhibit significant differences between the two groups. Patients in the CS group had a lower preoperative ankle-brachial index (0.48 ± 0.26 vs 0.52 ± 0.19; P = .032), more cases of complex AIOD (especially TASC D) (47.4% vs 9.5%; P < .001), more chronic total occlusive lesions (77.0% vs 31.1%; P < .001), and more severe calcification (20.7% vs 14.9%; P < .036). After propensity score matching, 50 patients (25 with CS and 25 with BMS) were selected. The results showed that only severe calcification (32.0% vs 8.0%; P = .034) and ankle-brachial index increase (0.45 ± 0.15 vs 0.41 ± 0.22; P = .038) were significantly different between the groups. In terms of surgical factors, patients in the CS group had more use of bilateral femoral or combined brachial artery percutaneous access (60.0% vs 12.0%; P < .001), more number of stents used (2.3 ± 1.2 vs 1.3 ± 0.7; P < .001), longer mean stent length (9.3 ± 3.3 vs 5.8 ± 2.6 cm; P < .001), and more catheter-directed thrombolysis treatment (32.0% vs 4.0%; P = .009). Multivariate Cox survival analysis showed that severe calcification (hazard ratio, 1.32; 95% confidence interval, 1.04-1.85; P = .048) was the only independent predictor of the primary patency rate. ConclusionsAll patients with AIOD who underwent endovascular therapy were included and achieved good outcomes with both CSs and BMSs. The influence of confounding factors in the two groups was minimized by propensity score matching, and the 5-year patency rates were generally similar in the unmatched and matched cohorts. Postoperative hemodynamic improvement was more obvious in patients in the CS group. For more complex lesions, CS is recommended to be preferred. Especially for severe calcification lesions, which is the only independent predictor of primary patency, CS showed obvious advantages. Further studies with more samples are needed to investigate the role of stent types in AIOD treatment.

Expanded polytetrafluoroethylene (ePTFE)-covered stents versus bare stents for transjugular intrahepatic portosystemic shunt in people with liver cirrhosis.

Expanded polytetrafluoroethylene (ePTFE)-covered stents versus bare stents for transjugular intrahepatic portosystemic shunt in people with liver cirrhosis.

Outcomes of covered stents versus bare-metal stents for subclavian artery occlusive disease.

To compare the clinical efficacy of covered stents and bare-metal stents in the endovascular treatment of subclavian artery occlusive disease. Between January 2014 and December 2020, 161 patients (112 males) underwent stenting of left subclavian arteries; CSs were implanted in 55 patients (34.2%) and BMSs in 106 (65.8%). Thirty-day outcomes, mid-term patency, and follow-up results were analyzed with Kaplan-Meier curves. Relevant clinical, anatomical, and procedural factors were evaluated for their association with patency in the two groups using Cox proportional hazards regression. Mean follow-up was 45 ± 18 months. The primary patency was 93.8% (95% CI, 81.9%-98.0%) in the covered stent group and 73.7% (95% CI, 63.2%-81.6%; P = 0.010) in the bare-metal stent group. The primary patency in the total occlusion subcategory was significant in favor of CS (93.3%, 95% CI, 61.26%-99.0%) compared with BMS (42.3%, 95% CI, 22.9%-60.5%; P = 0.005). Cox proportional hazards regression indicated that the use of BMSs [hazard ratio (HR), 4.90; 95% CI, 1.47-16.31; P = 0.010] and total occlusive lesions (HR, 7.03; 95% CI, 3.02-16.34; P < 0.001) were negative predictors of patency, and the vessel diameter (HR, 3.17; 95% CI, 1.04-9.71; P = 0.043)) was a positive predictor of patency. Compared with bare stents, covered stents have a higher midterm primary patency in the treatment of subclavian artery occlusive disease.

Contemporary Minimally Invasive Surgery for TASC-D Aorto-Iliac Lesions: Analysis of Outcomes and Risk Factors for Primary and Secondary Patency

For complex extensive TASC-II D lesions, the standard of care remains conventional surgery. Nevertheless, guidelines tend to broaden endovascular surgery indications in expert centers for patients at high surgical risk with TASC-II D lesions. Due to the increasing use of endovascular surgery in this setting, we planned to evaluate the patency rate of this approach. We conducted a retrospective study in a tertiray center. All patients treated for symptomatic peripheral arterial disease (PAD) with classified D lesions according to the TASC-II classification and requiring management of the aortoiliac bifurcation were retrospectively included between January 1, 2007 and December 31, 2017. The type of surgical approach was classified as a pure percutaneous approach or hybrid surgery. The main objective was to describe long-term patency results. The secondary objectives were to identify risk factors for loss of patency and long-term complications. The primary outcomes were primary patency, primary assisted patency and secondary patency at 5 years of follow-up. 136 patients were included. For the overall population, the primary, primary assisted and secondary patency proportions at 5 years were: 71.6% (95% CI 63.2% -81%), 82.1% (95% CI 74.9% - 89.3%), 96.3% (95% CI 92-100%), respectively. For primary patency, there was a significant difference in favor of the covered stent group at 36 months (p <0.01) and 60 months (p = 0.037). In a multivariate model, only CS and age were associated with a better primary patency (HR 0.36, CI95% [0.15 - 0.83], p=0.0193 and a HR 0.07, 95%CI [0.05-0.09], p=0.005, respectively). The overall rate of perioperative complications was 11%. We report that endovascular and hydrid surgery are safe and effective in the management of TASC-D complex aortoiliac lesions in mid to long-term follow-up. Short- and long-term complications were all considered as minor.

Prospective, randomized, multicenter clinical study comparing a self-expanding covered stent to percutaneous transluminal angioplasty for treatment of upper extremity hemodialysis arteriovenous fistula stenosis

Use of a covered stent after percutaneous transluminal angioplasty (PTA) was compared to PTA alone for treatment of upper extremity hemodialysis patients with arteriovenous fistula (AVF) stenoses. Patients with AVF stenosis of 50% or more and evidence of AVF dysfunction underwent treatment with PTA followed by randomization of 142 patients to include a covered stent or 138 patients with PTA alone. Primary outcomes were 30-day safety, powered for noninferiority, and six-month target lesion primary patency (TLPP), powered to test whether TLPP after covered-stent placement was superior to PTA alone. Twelve-month TLPP and six-month access circuit primary patency (ACPP) were also hypothesis tested while additional clinical outcomes were observed through two years. Safety was significantly non-inferior while six- and 12-month TLPP were each superior for the covered stent group compared to PTA alone (six months: 78.7% versus 55.8%; 12 months: 47.9% versus 21.2%, respectively). ACPP was not statistically different between groups at six-months. Observed differences at 24 months favored the covered-stent group: 28.4% better TLPP, fewer target-lesion reinterventions (1.6 ± 1.6 versus 2.8 ± 2.0), and a longer mean time between target-lesion reinterventions (380.4 ± 249.5 versus 217.6 ± 158.4 days). Thus, our multicenter, prospective, randomized study of a covered stent used to treat AVF stenosis demonstrated noninferior safety with better TLPP and fewer target-lesion reinterventions than PTA alone through 24 months.

Editor's Choice – Two Year Results of the Randomised DISCOVER Trial Comparing Covered Versus Bare Metal Stents in the Common Iliac Artery

It has been suggested that covered stents (CS) may lower restenosis rates compared with bare metal stents (BMS) after endovascular treatment of the common iliac artery. This trial aimed to provide additional evidence on the efficacy of CS vs. BMS in the common iliac artery. This multicentre, randomised, single blind controlled superiority trial compared balloon expandable CS and balloon expandable BMS for advanced atherosclerotic lesions in the common iliac artery; this was defined as a stenosis > 3 cm in length or occlusion. The primary end point was freedom from binary restenosis after two years of follow up. The study was conducted according to the principles of the Declaration of Helsinki (version: October 2008) and registered with the Dutch Trial register (NTR3381). One hundred and seventy-four limbs were included between 2012 and 2019 with 87 limbs in each group. Six patients crossed over from the BMS group to the CS group but were analysed according to an intention to treat principle. Freedom from binary restenosis after two years of follow up was 84.7% (95% CI 76.7 - 92.7%) in the BMS group and 89.1% (95% CI 82.4 - 95.8%) in the CS group (p= .40). Freedom from occlusion was 95.0% (95% CI 90.3 - 95.7%) in the BMS group and 96.4% (95% CI 92.5 - 100%) in the CS group (p= .66). Freedom from target lesion revascularisation was 91.1% (95% CI 84.8 - 97.3%) and 95.2% (95% CI 90.7 -99.7%), respectively (p= .31). Technical success, complications, haemodynamic success, and clinical success were also comparable between both groups. Per-protocol analysis did not affect the outcomes of the study. No difference was found between balloon expandable CS and BMS for treating advanced atherosclerotic lesions of the common iliac artery.

A meta-analysis of combined generic-covered stent-graft with or without bare-metal stent for refractory variceal bleeding.

The meta-analysis was conducted to systematically assess the efficacy and safety of generic stent-graft/bare-stent combination compared with Fluency stent alone in transjugular intrahepatic portosystemic shunt procedure for refractory variceal bleeding. PubMed, EMBASE, Scopus, Web of Science and the Cochrane Database were searched for relevant studies from January 1990 to September 2020; outcome measures studied were primary patency, hepatic encephalopathy, survival, re-bleeding and portal venous pressure. Four studies (1 randomised controlled trial and 3 retrospective studies) with 449 subjects (157 patients in the combined stent group and 292 patients in the covered stent group) were included. No significant difference was observed in the incidence of mortality (hazard ratio [HR] = 1.069, 95% confidence interval [CI] [0.524, 2.178]), hepatic encephalopathy (odds ratio [OR] = 0.860, 95% CI [0.341, 2.169], P = 0.750) and re-bleeding (OR = 1.049, 95% CI [0.226, 4.881], P = 0.951). Compared with Fluency stent alone, combination therapy was associated with moderate decrease in outcomes on the post-operative portal venous pressure (standard mean difference [SMD] -0.210, 95% CI [-0.418, -0.001], P = 0.049) and was not associated with significant decrease in outcomes on the pre-operative portal venous pressure (SMD - 0.129, 95% CI [-0.336, 0.078], P = 0.223). The primary patency was significantly lower in the Fluency/bare-stent combination group (HR = 0.473, 95% CI [0.288, 0.776]). Generic stent-graft/bare-stent combination therapy was associated with significantly lower primary patency compared to Fluency stent alone.

Covered Stents vs. Angioplasty for Common Iliac Artery In Stent Restenosis: A Retrospective Comparison

The optimal endovascular treatment for common iliac artery in stent re-stenosis has yet to be assessed. Treatment options include, among others, angioplasty alone and repeated stenting with covered stents. This study retrospectively compared patency and target lesion revascularisation of these treatments. All patients who underwent endovascular treatment of common iliac artery in stent re-stenosis between 2007 and 2017 were included retrospectively. The primary end point was freedom from re-stenosis. Secondary endpoints were target lesion revascularisation rate (TLR) and freedom from occlusion during follow up. Seventy-four interventions were included, consisting of 37 angioplasties and 37 covered stent placements in 57 patients. Freedom from re-stenosis at four years was 72.6% (95% confidence interval [CI] 51.8% - 88.7%) in the covered stent group vs. 43.5% (95% CI 25.9% - 59.8%) in the percutaneous transluminal angioplasty (PTA) group (p= .003). The target lesion revascularisation (TLR) rate was 16.4% (95% CI 7.1% - 35.6%) and 43.6% (95% CI 28.0% - 63.2%) respectively (p= .020). There was no difference in freedom from occlusion; this was 90.8% (95% CI 73.9% - 97.0%) in the covered stent group and 79.1% (95% CI 58.4% - 90.3%) in the PTA group (p= .49). The difference in freedom from re-stenosis and TLR remained significant after sensitivity and multivariable analyses. Covered stents offer better outcomes for common iliac artery in stent re-stenosis than angioplasty alone.

Preventive covered stent placement at the gastroduodenal artery stump in angiogram-negative sentinel hemorrhage after pancreaticoduodenectomy.

To evaluate the clinical outcomes of preventive covered stent placement at the gastroduodenal artery stump in patients with angiogram-negative sentinel hemorrhage after pancreaticoduodenectomy. Between July 2006 and September 2018, patients undergoing computed tomography angiography or diagnostic angiography for sentinel hemorrhage after pancreaticoduodenectomy were retrospectively reviewed. Patients having angiogram-negative angiography and undergoing preventive covered stent placement or conservative treatment were included. Clinical outcomes, technique success, and complications were evaluated. A total of 25 patients (mean age 62.5years) were evaluated, including 15 patients underwent preventive covered stent placement at the gastroduodenal artery stump and 10 patients received conservative treatments. The clinical success rates were 50% (5/10) and 86.7% (13/15) for conservative treatments and covered stent groups, respectively (p = 0.07). In the conservative treatment group, delayed massive hemorrhage occurred in five patients, two of whom died of recurrent bleeding due to gastroduodenal artery pseudoaneurysm within 16days, and two had intraluminal hemorrhage within 5days. In the covered stent group, one patient had inferior pancreaticoduodenal artery pseudoaneurysm 1day after the placement of the covered stent, and one had recurrent bleeding due to duodenal ulcer within 14days. The 30-day mortality was 40% (4/10) and 0 in the conservative treatment and covered stent groups, respectively (p = 0.02). The difference in the overall survival was nonsignificant between the two groups (p = 0.23). The preventive covered stent placement at the gastroduodenal artery stump is safe and reduces delayed massive hemorrhage and short-term mortality in patients with angiogram-negative sentinel hemorrhage after pancreaticoduodenectomy.

Covered Stents for Endovascular Treatment of Aortoiliac Occlusive Disease: A Systematic Review and Meta-Analysis.

The treatment of aortoiliac occlusive disease (AIOD) has largely shifted to endovascular techniques, with primary stenting constituting the preferred treatment approach. The goal of the current study was to summarize available literature and to determine whether covered stents are superior to bare metal stents for the treatment of AIOD, in terms of both periprocedural and long-term outcomes. A meta-analysis of 47 studies was conducted with the use of random effects modeling. The incidence of adverse events during follow up among the individual included studies was synthesized. Most of the lesions were located at the common iliac arteries and were chronic total occlusions. The procedure was technically successful in almost all cases in both groups, with a low rate of periprocedural complications observed in both groups. The reported primary patency rates for the non-covered and covered stent group during an average follow up of 24.3 months among the individual studies, were 84% and 92% respectively, while surgical or endovascular re-intervention was required in 10% of non-covered stent cases and in 6% of covered stent cases. Eight studies comparing covered vs non-covered stents in terms of patency demonstrated superiority of covered stents (OR: 2.47; 95% CI: 1.01-6.01; p = 0.047 Combining TASC C/D lesions together 12 studies reported 92% (95%CI:89%-95%) primary patency in the covered stent group, while 7 studies reported 75% (95%CI: 60%-88%) primary patency for cases treated with non-covered stents. This study demonstrated that covered stents are safe and effective when utilized for the treatment of AIOD. Covered stents were associated with a statistically significant higher odds of primary patency in both the overall cohort and in more complex TASC C/D lesions. However, additional high-quality comparative analyses between covered vs bare metal stents and between several types of covered stents are needed to determine the most optimal treatment modality for AIOD.

Clinical evaluation the success rate and complications of fluoroscopically guided removal of tracheal tube metallic stents

BackgroundLong-term placement of airway stents has a high probability of restenosis of the airway due to granulation tissue hyperplasia, and it is difficult to remove the stent. Our aim is to evaluate the success rate and complications of removal of tracheal tube metallic stents under fluoroscopic guidance, and to compare the difference between uncovered stent and covered stent.MethodsWe retrospectively reviewed 45 cases (31 males and 14 females; age, 12–71 years) of tracheal metallic stent removal performed at our center between January 2014 and December 2019. Covered stents were applied in 36 cases, and uncovered stents were applied in 9 cases. In the covered stent group, 15 patients presented with granulation tissue at both ends; 3 cases, with stent fracture; and 2, with stent intolerance due to severe airway foreign body sensation. In the uncovered stents group, all patients presented with granulation tissue formation; 2 patients, with stent fracture; and 1 patient, with stent intolerance.ResultsA total of 41 (91.1%) stents were successfully removed (34 [94.4%] in the covered stent group and 7 [77.8%] in the uncovered stent group). The average duration of stent placement was 3.2 ± 0.7 and 2.5 ± 1.2 months in the covered stent group and uncovered stent group, respectively. With regard to the complications, hemoptysis occurred in 4 cases (average blood volume lost, 100 ml), tracheal mucosa tear occurred in 5 cases, tracheal collapse requiring emergency airway stent placement occurred in 1 case, and tracheal rupture requiring emergency surgical suture occurred in 1 case. No procedure-related deaths occurred in either group.ConclusionsIt is safe to remove the metal stent of the tracheal tube under the guidance of fluoroscopy, with low complications, and can avoid the long-term placement of the airway stent.

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

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.

Early and late outcome of covered and non-covered stents in the treatment of coarctation of aorta- A single centre experience

ObjectiveStenting of coarctation of aorta with covered or uncovered stents is the accepted modality of treatment in older children and adults. The indications which mandate the use of covered stents are still unclear. We attempted to study the early and late outcomes after stenting of native and recurrent coarctation of aorta with uncovered and covered stents. MethodThis is a retrospective study of patients who underwent stenting for coarctation of aorta with covered or non-covered stents at our institute. Early and late outcome for both the groups were studied. ResultsTwenty patients underwent implantation of covered stent and twenty five patients had uncovered stent implantation. Patients in the covered stent group were older and had greater basal pressure gradient. More patients in the covered stent group had residual gradient >10 mm Hg after the procedure. There was no mortality or aortic wall injury in either group. Four patients in the covered stent group underwent planned re-intervention and two had unplanned re-intervention. None of the patients in the uncovered stent group had re-intervention. Higher incidence of late lumen loss was noted in the covered stent group. ConclusionUncovered stents can be safely implanted with minimal risk of aortic wall injury in patients with low risk anatomic features. Covered stent implantation is associated with higher incidence of planned and unplanned re-intervention.

The Role of Endovascular Stents in an Experimental Model of Traumatic Arterial Occlusion – the Temporary Endo-Shunt

Background.We aimed to evaluate patency following the deployment of a bare-metal (BMS) or covered stent (CS) across a traumatic occlusive arterial lesion and to estimate the feasibility of urgent stent placement for temporary endovascular shunting.&#x0D; Methods. Fifteen sheep (25-45 kg) underwent laparoscopic creation of a left external iliac artery (EIA) thrombosis by means of repeated clamping. Animals were then randomized into one of three groups: no-treatment (control group), a BMS group or CS group. Animals were followed up for 30 days with no anticoagulants or anti-platelet drugs administered postoperatively. Doppler ultrasound, computed tomography angiography (CTA), and digital subtraction angiography (DSA) were used to evaluate EIA patency.&#x0D; Results.Stent implantation resulted in the restoration of in-line flow through the EIA in all cases. The peak systolic velocity (PSV) in the injured limb increased from 10 (0–16) to 31 (28–37) cm/sec in the BMS group (p&lt;0.0001) and from 15 (7–18) to 24 (21–29) cm/sec in the CS group (p=0.043) immediately after stent deployment (both p=0.001 compared to the control group). There was no difference in the PSV between the groups at post-injury day 3, and thereafter. Day-14 CTA and day-30 DSA demonstrated only one patent stent in each study group.&#x0D; Conclusions.Stent (BMS or CS) implantation restores arterial patency of a traumatic occlusive lesion for a period of less than three days in our ovine model. While acute recanalization of the injury with stent implantation may be used for temporary endovascular shunting, long-term patency remains a problem.

Abstract No. 2 ■ ABSTRACT OF THE YEAR Interim results from the prospective, randomized AVeNEW study

To assess the results using the ePTFE-covered, self-expanding COVERA Vascular Covered Stent for the treatment of stenotic lesions in the venous outflow of upper extremity hemodialysis arteriovenous (AV) fistulae. Thirty-five centers in the United States, Europe, Australia, and New Zealand randomized 280 patients with stenotic lesions (≥ 50%) and clinical or hemodynamic evidence of AV fistula dysfunction to either PTA alone (n = 138) or PTA followed by covered stent placement (n = 142). Primary endpoints were 6-month target lesion primary patency (TLPP) and 30-day safety. Secondary measures included TLPP, access circuit primary patency (ACPP), index of patency function (IPF), and the number of reinterventions needed to maintain patency at 12 months, with ongoing data collection to 3 years. Safety at 30 days was non-inferior between groups (P = 0.002) while TLPP at 180 days (Kaplan-Meier analysis) was superior for the covered-stent group (78.7%) compared with the PTA group (47.9%; one-sided P < 0.001). 83.9% of patients were followed to 12 months; 34 patients died (10.6% covered-stent group; 14.5% PTA group) while 10 patients withdrew or were lost to follow-up (4.2% covered-stent group; 2.9% PTA group) prior to 12-month evaluation. TLPP (K-M analysis) was superior for the covered stent group (57.5%) compared to the PTA (21.2%; P < 0.001) at 365 days. ACPP was also significantly better for the covered-stent group at 12 months, 28.9% versus 17.7% respectively (P = 0.02). The mean number of reinterventions in the access circuit to maintain patency was 0.8 + 1.0 for the covered-stent group compared to 1.7 + 1.3 for the PTA group. AVeNEW is the first level-one clinical trial dedicated to the use of a covered stent designed to treat stenoses in AV fistulae. The covered stent provided significantly better TLPP and non-inferior safety compared to the randomized PTA group at 6 months. At 12 months, TLPP was statistically better for the covered-stent group (P < 0.001) as was ACPP (P = 0.02) while about half as many reinterventions were required to maintain secondary circuit patency.

No evidence of improved efficacy of covered stents over uncovered stents in percutaneous palliation of malignant hilar biliary obstruction: results of a prospective randomized trial.

To investigate whether covered stents show a higher efficacy than uncovered stents in percutaneous treatment of malignant hilar biliary obstruction. Patients with obstructive jaundice caused by an unresectable hilar malignancy were included after failed endoscopic intervention in a prospective randomized trial comparing expanded polytetrafluoroethylene and fluorinated ethylene propylene (ePTFE-FEP)-covered nitinol stents with uncovered nitinol stents. Exclusion criteria were as follows: primary tumors existing more than 3months, a biliodigestive anastomosis, previous stenting, and a Karnofsky score of less than 50. Safety, clinical success, and adjuvant chemotherapy were compared as well as occlusion rate, patency, and survival. A total of 120 patients were included. One patient was post hoc excluded. Fourteen patients who died within 7days and one patient without patency data were excluded from patency analysis. Serious adverse events (p = 0.4), 30-day mortality (p = 0.5), and clinical success (p = 0.8) were equivalent for both stent groups. Twenty-one out of 61 (34%) patients in the covered and 24/58 (41%) in the uncovered stent groups received adjuvant chemotherapy (p = 0.5). Occlusion rate was 54% (27/50) in the covered stent group and 57% (31/54) in the uncovered stent group (p = 0.8). Median patency was 229days (95% CI 113-345) for covered stents and 130days (95% CI 75-185) for uncovered stents (p = 0.1). Median survival in patients with covered stents was 79days (95% CI 52-106) and with uncovered stents 92days (95% CI 60-124) (p = 0.3). In malignant hilar biliary obstruction, there is no evidence that ePTFE-FEP-covered stents are superior to uncovered stents in terms of safety, clinical success, adjuvant chemotherapy, patency, or survival. • Percutaneous palliation of hilar biliary obstruction is feasible with both uncovered and covered stents. • Clinical success in terms of bilirubin decrease and adjuvant chemotherapy is achievable with both stents. • Thirty-day mortality is considerable when stenting is also offered to patients with a low performance status.

PC158 Long-Term Outcomes After Endovascular Stent Placement for Symptomatic, Long-Segment Superficial Femoral Artery Lesions

Endovascular intervention is commonly pursued for the treatment of symptomatic, long-segment superficial femoral artery (SFA) disease. The relative effectiveness and comparative long-term outcomes among bare-metal stents (BMS), covered stents (CS), and drug-eluting (DES) stents for long-segment SFA lesions remain uncertain. A retrospective cohort study identified consecutive patients with symptomatic SFA occlusions measuring at least 15 cm who received an endovascular stent (BMS, CS, or DES). The primary outcome of interest was patency, while secondary outcomes included postoperative presentation with acute limb ischemia (ALI), number of reoperations, and limb salvage. Patency rates were compared using time-to-event analysis and log-rank tests. From 186 patients that were identified, a total of 215 procedures were analyzed (BMS: 113 [52%]; CS: 75 [35%]; DES: 27 [13%]) with a median follow-up time of 56 months (although the follow-up for DES was less: median, 10 months; P < .001). There were no significant differences among the groups with respect to mean age, diabetes status, renal dysfunction, and lower extremity runoff (mean 2.0 ± 0.7 vessels). The mean length of the SFA lesion being treated in this series was 27 ± 8 cm (also similar across all groups, P = .165). Although primary and secondary patency rates were not significantly different among the stent types, DES is associated with an improved short-term primary-assisted patency, with 6-, 12-, and 24-month rates of 92%, 92%, and 83%, respectively. This is compared to 80%, 57%, and 47% for BMS, and 80%, 49%, and 41% for CS, respectively (log-rank test: P = .009; Fig 1). In comparing only BMS with CS, 5- and 8-year primary-assisted patency rates are also higher among BMS: 60% and 60% vs 33% and 33% for CS, respectively (P = .011; Fig 2). Zero DES patients have presented postoperatively with ALI compared to 3% of BMS patients and 13% of CS patients (P = .004). Similarly, the CS group had a higher rate of subsequent open revascularization (32%) compared with BMS (24%) and DES (7%; P = .038). Although long-term primary-assisted patency is greater in BMS as compared to CS, primary and secondary patency rates among all stent types are similar. CSs are associated with an increased risk of postoperative acute limb ischemia and subsequent open revascularization.Fig 2View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Thrombosis after transjugular intrahepatic portosystemic shunt: an ominous sign?

Transjugular intrahepatic portosystemic shunt (TIPS) is increasingly used for the treatment of complications of portal hypertension, especially variceal bleeding and ascites refractory to conventional therapy (1,2). Development of thrombosis after TIPS placement is an uncommon complication, which was reported to occur in only 3% to 10% of patients when bare stents were used in several large series (3-6). Thrombosis usually develops acutely either at the time the stent is being deployed or within several days of TIPS placement (2,6). The cause of the thrombosis may be leakage of bile into the shunt, hypercoagulable syndromes, stent mispositioning, suboptimal stent sites, or inadequate coverage of the TIPS tract with sufficient stent (2,7-12). The direct result of thrombosis development is occlusion of the TIPS device, blocking flow in the portal vein and directly resulting in the recurrence of the complication of portal hypertension in addition to potentially causing bowel ischemia as a result of venous congestion in cases of thrombosis extending into the splenic and mesenteric veins (7). Thrombosis can be identified by Doppler ultrasound and patency can be re-established by repeat catheterization (2,7). The development of acute thrombosis also can be effectively prevented by prophylaxis anticoagulation or using e-PTFE-coated stents (13,14). One randomized controlled trial (RCT) showed that use of phenprocoumon (an anticoagulant) was associated with a lower rate of complete occlusion within the first three months following TIPS placement (13). In the RCT by Bureau (14), no early thrombosis was observed in the e-PTFE covered stent-graft group (n=39) as compared with three cases in the covered stent-graft group (n=41). A recent RCT also showed that early thromboses were less frequent in patients receiving covered stent TIPS compared with those receiving bare stents (10/67 in bare stent group vs. 3/63 in the covered stent group) (15).