Mortality in patients undergoing covered self-expandable metal stent revisions in malignant biliary stricture: Does pathology matter?

Background and Aims

Partially covered metal stents have been extensively used for palliation of obstructive jaundice in malignant distal biliary strictures and can be removed in cases of malfunction or need for tissue diagnosis. We investigated independent predictors of mortality in patients undergoing partially covered metal stents revision (i.e., removal and replacement).

Methods

Patients with a distal malignant biliary obstruction palliated with a partially covered metal stent were followed-up prospectively over 5 years until malfunction or death. All patients who required removal of their partially covered metal stents were captured in a specific database. Multivariate analysis was performed on non-surgical patients to assess for independent predictors of death using known risk factors including type of malignancy (adenocarcinoma versus all others), age greater than 55, gender, and exposure to adjuvant chemotherapy and/or radiotherapy.

Results

Forty-two patients (28 men, mean age of 62 ± 12 years) underwent partially covered metal stents removal. Of these, biliary drainage was achieved in 38 patients by placement of a new partially covered metal stent (n = 32) or plastic stent (n = 6). The remaining 4 patients did not undergo stent replacement because of refusal (2), resolution of obstruction (1) and unrelated death (1). Long-term follow-up post removal in patients who were not surgical candidates (n = 31) was 35 weeks (95% CI 28–40), with a survival rate of 29% at 10 months. Logistic regression analysis in the 31 patients with unresectable disease showed that a histologic diagnosis of adenocarcinoma was associated with increased mortality post partially covered metal stents revision.

Conclusions

Partially covered metal stents revision should be undertaken especially when dealing with a non-adenocarcinoma type cancer.     

Intravascular ultrasound assessed incomplete stent apposition and stent fracture in stent thrombosis after bare metal versus drug-eluting stent treatment the Nordic Intravascular Ultrasound Study (NIVUS)

Background

This prospective multicenter registry used intravascular ultrasound (IVUS) in patients with definite stent thrombosis (ST) to compare rates of incomplete stent apposition (ISA), stent fracture and stent expansion in patients treated with drug-eluting (DES) versus bare metal (BMS) stents. ST is a rare, but potential life threatening event after coronary stent implantation. The etiology seems to be multifactorial.

Methods

124 patients with definite ST were assessed by IVUS during the acute ST event. The study was conducted in 15 high-volume percutaneous coronary intervention -centers in the Nordic–Baltic countries.

Results

In early or late ST there were no differences in ISA between DES and BMS. In very late ST, ISA was a more frequent finding in DES than in BMS (52% vs.16%; p = 0.005) and the maximum ISA area was larger in DES compared to BMS (1.1 ± 2.3 mm² vs. 0.1 ± 0.5 mm²; p = 0.004). Further, ISA was more prevalent in sirolimus-eluting than in paclitaxel-eluting stents (58% vs. 37%; p = 0.02). Stent fractures were found both in DES (16%) and BMS (24%); p = 0.28, and not related to time of stent thrombosis occurrence. For stents with nominal diameters ≥ 2.75 mm, 38% of the DES and 22% of the BMS had a minimum stent area of less than 5 mm²; p = 0.14.

Conclusions

Very late stent thrombosis was more prevalent and associated with more extensive ISA in DES than in BMS treated patients. Stent fracture was a common finding in ST after DES and BMS implantation.     

Antral localization worsens the efficacy of enteral stents in malignant digestive tumors

Background and aims

Malignant gastric outlet obstruction can be treated by means of enteral stenting or surgical gastrojejunalanatomosis. We evaluated in a prospective and multicentre study the efficacy of the enteral stent on food intake, the quality of life impact, and the relationship between efficacy and determined clinical and technical parameters.

Patients and methods

Seventy one patients affected by symptoms arising from gastroduodenal obstruction due to malignant tumors, with criteria of irresecability, metastatic disease or very high surgical risk, were treated by means of self expanding metal stents. We used the GOOSS index to evaluate efficacy, and the Euro Qol-5D index to evaluate quality of life.

Results

Before stenting patients with GOOSS 0 and 1 were 68 (98.5%). After stenting patients with GOOSS 2 and 3 (semisolid and solid food) were 58 (84,1%) (P<.0001). The Euro Qol-5D index measured before and a month after stenting were 10.17 and 10.04 respectively (P=.6). The median survival was 91 days (9-552). The enteral stents for localised tumors in the duodenum and the gastrojejunalanastomosis were effective in 26 patients (70.2%) and 13 patients respectively (86.6%), while the enteral stents of tumors in the antrum were effective in only 5 patients (29.4%).

Conclusions

The palliative treatment of malignant gastric outlet obstruction with a uncovered metal stent produces a significant improvement of oral food intake and maintains the overall quality of life index. The antral localization is associated with a lower efficacy of the procedure.     

Transapical mitral valved stent implantation: Enhanced survival and decreased paravalvular leakages

Background/Objectives

This study presents the recent results of transapical implantation of a new design of a mitral valved stent with up to three months follow-up.

Methods

A self-expanding re-designed mitral valved stent was implanted via transapical approach into the beating heart of eight pigs. Echocardiographic- and hemodynamic parameters were assessed before (n = 8), at 1 h (n = 8), at one month (n = 6), at two months (n = 2), and at three months (n = 1) after implantation and a cardiac CT was conducted.

Results

The stent was successfully deployed in all animals. Two animals died within the first month due to incorrect fixation force. Echocardiographic evaluation showed low gradients (3.9 ± 1.4 mm Hg and 1.9 ± 0.8 mm Hg across the valved stent and aortic valve) and a normal mitral annular plane systolic excursion (1.1 ± 0.2 cm) after one month. No paravalvular leakages (PVL) were detected after 1 h. The pulmonary artery pressure did not increase after valved stent implantation (p ≥ 0.106). The pulmonary capillary wedge pressure (PCWP) slightly increased to 16 ± 3 mm Hg after one month (p = 0.033). The left ventricular end-diastolic pressure was mildly elevated (15.8 ± 8.6 mm Hg) after one month.

Conclusions

Secure deployment and correct position of the valved stents were reproducibly achieved in the off-pump implantation procedure. No paravalvular leakages after 1 h as well as low gradients, few stent fractures and a normal longitudinal function after one month were achieved with this newly developed and well-aligned prototype. However, a number of challenges have been identified during this study and potential for improvement has been identified.     

Side-by-Side Versus Stent-in-Stent Deployment in Bilateral Endoscopic Metal Stenting for Malignant Hilar Biliary Obstruction

Background

The clinical differences between side-by-side and stent-in-stent deployment using a self-expanding metal stent for hilar malignant obstruction have not been evaluated.

Aims

The purpose of this study was to compare the clinical features between side-by-side and stent-in-stent deployment.

Methods

We compared side-by-side and stent-in-stent deployment in 52 consecutive patients with malignant hilar biliary obstruction who underwent endoscopic bilateral drainage using self-expanding metal stent. Side-by-side deployment (SBS group) was performed in 28 patients from 2002 to 2005, and stent-in-stent deployment (SIS group) in 24 patients from 2006 to 2010. Technical success, functional success, complications, stent occlusion and cumulative stent patency in the SBS and SIS groups were evaluated and compared retrospectively.

Results

There were no significant inter-group differences in technical success (SBS vs. SIS, 89 vs. 100?%, respectively), functional success (96 vs. 100?%), early complications (11 vs. 4?%), late complications (32 vs. 8?%) or stent occlusion (20 vs. 42?%). The incidence of complications was significantly higher for SBS than for SIS (44 vs. 13?%; p?=?0.016). Cumulative stent patency was significantly better for SBS than for SIS (log-rank, p?=?0.047). SBS was not associated with significantly longer cumulative stent patency in univariate Cox proportional hazard analysis (HR 0.35; 95?% CI 0.12?C1.03; p?=?0.056) and multivariate analysis (HR 0.39; 95?% CI 0.13?C1.16; p?=?0.090).

Conclusions

The incidence of complications is higher for side-by-side than stent-in stent deployment in bilateral metal stenting. In terms of cumulative stent patency, side-by-side deployment tends to be more effective than stent-in-stent deployment.     

Relation between poststenting peristent plaque components and late stent malapposition after drug-eluting stent implantation: Virtual histology-intravascular ultrasound analysis

Background

Impact of plaque composition on late stent malapposition (LSM) after drug-eluting stent (DES) implantation has not been evaluated.

Methods

We evaluated the relation between plaque components at poststenting peristent area (between external elastic membrane and stent areas) and LSM after DES implantation in 266 patients (314 native lesions; paclitaxel-eluting stent in 205 lesions, sirolimus-eluting stent in 66 lesions, zotarolimus-eluting stent in 32 lesions and everolimus-eluting stent in 11 lesions) in whom virtual-histology intravascular ultrasound was performed at index (poststenting) and follow-up (mean: 11.7 ± 4.8 months).

Results

LSM occurred in 24 patients with 30 lesions (9.6%) and there were no significant differences in the incidences of LSM among 4 DES groups [21/205 (10.2%) in paclitaxel-eluting stent, 6/66 (9.1%) in sirolimus-eluting stent, 2/32 (6.3%) in zotarolimus-eluting stent and 1/11 (9.1%) in everolimus-eluting stent, p = 0.5)]. Patients with LSM were presented with more acute myocardial infarction (50% vs. 28%, p = 0.026) and were more diabetics (50% vs. 30%, p = 0.030) compared with those without LSM. Lesions with LSM had more poststenting peristent %necrotic core (NC) volume compared with those without LSM (25.8 ± 11.1% vs. 21.0 ± 5.7%, p < 0.001). Independent predictors of LSM were poststenting peristent %NC volume [odds ratio (OR); 1.216, 95% CI; 1.053–1.405, p = 0.008], acute myocardial infarction (OR; 2.897, 95% CI; 1.675–4.118, p = 0.029), and diabetes mellitus (OR; 2.413, 95% CI; 1.543–3.996, p = 0.038).

Conclusions

Poststenting peristent NC component especially in patients with acute myocardial infarction and in those with diabetes mellitus is associated with the development of LSM after DES implantation.     

Análisis combinado de dos ensayos aleatorizados de comparación de stents con recubrimiento de titanio-óxido nítrico con stents liberadores de fármacos en el IAMCEST

Introduction and objectives

We performed a pooled analysis based on patient-level data from the TITAX-AMI and BASE-ACS trials to evaluate the outcome of titanium-nitride-oxide-coated bioactive stents vs drug-eluting stents in patients with ST-segment elevation myocardial infarction at 2-year follow-up.

Methods

The TITAX-AMI trial compared bioactive stents with paclitaxel-eluting stents in 425 patients with acute myocardial infarction. The BASE-ACS trial compared bioactive stents with everolimus-eluting stents in 827 patients with acute coronary syndrome. The primary endpoint for the pooled analysis was major adverse cardiac events: a composite of cardiac death, recurrent myocardial infarction, or ischemia-driven target lesion revascularization at 2-year follow-up.

Results

The pooled analysis included 501 patients; 245 received bioactive stents, and 256 received drug-eluting stents. The pooled bioactive stent group was associated with a risk ratio of 0.85 for major adverse cardiac events (95% confidence interval, 0.53-1.35; P = .49) compared to the pooled drug-eluting stent group. Similarly, the pooled bioactive stent group was associated with a risk ratio of 0.71 for cardiac death (95% confidence interval, 0.26-1.95; P = .51), 0.44 for recurrent myocardial infarction (95% confidence interval, 0.20-0.97; P = .04), and 1.39 for ischemia-driven target lesion revascularization (95% confidence interval, 0.74-2.59; P = .30), compared to the pooled drug-eluting stent group. These results were confirmed by propensity-score adjusted analysis of the combined datasets.

Conclusions

In patients with ST-segment elevation myocardial infarction, bioactive stents were associated with lower rates of recurrent myocardial infarction compared to drug-eluting stents at 2-year follow-up; yet, the rates of cardiac death and ischemia-driven target lesion revascularization were similar.Full English text available from: www.revespcardiol.org/en     

Optical coherence tomography analysis of strut coverage in biolimus- and sirolimus-eluting stents: 3-Month and 12-month serial follow-up

Background

No randomized studies have been conducted to investigate serial changes in optical coherence tomography (OCT) analyses following implantation of biolimus-A9-eluting stents (BES) and sirolimus-eluting stents (SES).

Methods

A total of 60 patients fulfilling the study criteria were randomly assigned into BES (n = 30) and SES (n = 30) implantation groups. Serial OCT evaluation at post-procedure, 3- and 12-month follow-up was performed in 46 patients [BES (n = 22) and SES (n = 24)]. OCT analyses were compared according to the type of stents and the follow-up time intervals. The percentage of uncovered struts was defined as the ratio of uncovered struts to total struts in all cross-sections. The primary endpoint was the percentage change (Δ) of uncovered struts in the 3- and 12-month follow-up samples.

Results

The percentage of uncovered struts at the 3-month time period was not significantly different in the BES and SES groups; the median value (interquartile range) was 14.7% (0.0–23.4) versus 8.6% (0.7–21.5) (p = 0.98), respectively. However, OCT at the 12-month follow-up showed a significantly lower percentage of uncovered struts [2.6% (0.8–5.6) versus 6.2% (1.7–14.7), (p = 0.028), respectively] without significant difference of neointimal thickness. BES showed a greater reduction of percentage Δ of uncovered struts from 3–12 months than that of SES [− 17.2 ± 14.5% versus − 7.7 ± 16.3%, respectively (p = 0.043)].

Conclusions

Both drug-eluting stents showed a high percentage of incomplete strut coverage at 3 months. However, BES showed a significantly lower percentage of uncovered struts at 12 months compared to that of SES. This was achieved by superior strut coverage from 3 to 12 months.     

Late thrombosis of drug-eluting stents: a meta-analysis of randomized clinical trials

Purpose

Drug-eluting stents are commonly used for percutaneous coronary intervention. Despite excellent clinical efficacy, the association between drug-eluting stents and the risk for late thrombosis remains imprecisely defined.

Methods

We performed a meta-analysis on 14 contemporary clinical trials that randomized 6675 patients to drug-eluting stents (paclitaxel or sirolimus) compared with bare metal stents. Eight of these trials have reported more than a year of clinical follow-up.

Results

The incidence of very late thrombosis (>1 year after the index procedure) was 5.0 events per 1000 drug-eluting stent patients, with no events in bare metal stent patients (risk ratio [RR] = 5.02, 95% confidence interval [CI], 1.29 to 19.52, P = .02). Among sirolimus trials, the incidence of very late thrombosis was 3.6 events per 1000 sirolimus stent patients, with no events in bare metal stent patients (RR = 3.99, 95% CI, .45 to 35.62, P = .22). The median time of late sirolimus stent thrombosis was 15.5 months, whereas with bare metal stents it was 4 months. Among paclitaxel trials, the incidence of very late thrombosis was 5.9 events per 1000 paclitaxel stent patients, with no events in bare metal stent patients (RR = 5.72, 95% CI, 1.08 to 32.45, P = .049). The median time of late paclitaxel stent thrombosis was 18 months, whereas it was 3.5 months in bare metal stent patients.

Conclusions

Although the incidence of very late stent thrombosis more than 1 year after coronary revascularization is low, drug-eluting stents appear to increase the risk for late thrombosis. Although more of this risk was seen with paclitaxel stents, it remains possible that sirolimus stents similarly increase the risk for late thrombosis compared with bare metal stents.     

Neointimal coverage and stent strut apposition six months after implantation of a paclitaxel eluting stent in acute coronary syndromes: An optical coherence tomography study

Objectives

Prospective optical coherence tomography (OCT) study of strut apposition and neointimal hyperplasia thickness (NIH) of a paclitaxel eluting stent (PES), (Infinium, Sahajanand Medical Technologies Pvt Ltd.).

Background

Few data exist concerning neointimal coverage of PES. Uncovered and malapposed struts are more common following stenting in acute coronary syndromes (ACS) than in non-ACS lesions.

Methods

All consecutive patients with ACS, treated with the above PES for single native coronary lesions between August 2008 and January 2009, who consented to invasive follow-up with OCT at six months (N = 13), were included.

Results

At 6 months no patient demonstrated angiographic restenosis. 3180 struts from 20 stents were analyzed, and 91.3% were covered with neointima (NIH 204.8 ± 159.5 μm). Standard statistics and least squares estimates (LSE) derived from a hierarchical ANCOVA model to take into account clustering effects are presented. Rate of uncovered struts was 8.6%, LSE 7.39 (95% CI 3.05-11.73), malapposed struts 2.2%, LSE 1.76 (95% CI 0.05-3.58), and protruding struts 2.9%, LSE 2.8 (95% CI 1.35-4.65). The proportion of uncovered malapposed struts was significantly higher compared to uncovered embedded struts (55.7% vs. 6.8%, p < 0.01). In total, 5 (25%) PES were fully covered by neointima. No intracoronary thrombus or clinical events were detected.

Conclusions

Six months after implantation of a specific PES in patients with ACS, most of the stents were only partially covered with neointima, especially at sites of strut malapposition or protrusion. These findings emphasize the need for optimal stent apposition during implantation and for prolonged dual antiplatelet therapy.     

Comparison of frequency and severity of longitudinal stent deformation among various drug-eluting stents: An intravascular ultrasound study

Background

Longitudinal stent deformation (LSD) in drug-eluting stents (DES) has been described as a disruption of stent structure. This study aimed to compare first- versus second-generation DES with respect to their actual stent length post deployment.

Methods

A total of 617 DES for de novo coronary lesions in 552 patients were analyzed. Intravascular ultrasound (IVUS) was utilized to compare the degree and rate of LSD among six different DES types. IVUS-measured stent length was compared to the labeled length for calculation of absolute difference in stent length and relative absolute difference (absolute difference divided by the labeled length).

Results

The baseline characteristics were comparable between groups, except for higher calcification in the sirolimus-eluting stent (SES) group (p = 0.037). The absolute and relative difference in length showed the lowest degree in the SES group and the highest degree in the Endeavor zotarolimus-eluting stent group (p = 0.085 and 0.078, respectively). The percentage of more than 5% relative absolute difference was the lowest in the SES group compared to the other groups (p = 0.018). However, the percentage of significant (> 15%) relative absolute difference was similar among groups (p = 0.99). In multivariate linear regression analysis, labeled stent length and stent diameter, but not stent type, were identified as independent correlates to the absolute and relative difference in the actual stent length post-deployment.

Conclusion

This IVUS analysis confirms that among second-generation DES, there is overall similar frequency and severity of LSD when deploying in common coronary lesions.     

Management of occluded self-expanding biliary metal stents in malignant biliary disease

Background: Occlusion of self-expanding metal stents(SEMS) in malignant biliary obstruction occurs in up to 40% of patients. This study aimed to compare the different techniques to resolve stent occlusion in our collective of patients.Methods: Patients with malignant biliary obstruction and occlusion of biliary metal stent at a tertiary referral endoscopic center were retrospectively identified between April 1, 1994 and May 31, 2014. The clinical records were further analyzed regarding the characteristics of patients, malignant strictures, SEMS,management strategies, stent patency, subsequent interventions, survival time and case charges.Results: A total of 108 patients with biliary metal stent occlusion were identified. Seventy-nine of these patients were eligible for further analysis. Favored management was plastic stent insertion in 73.4% patients. Second SEMS were inserted in 12.7% patients. Percutaneous transhepatic biliary drainage and mechanical cleansing were conducted in a minority of patients. Further analysis showed no statistically significant difference in median overall secondary stent patency(88 vs. 143 days, P = 0.069), median survival time(95 vs. 192 days, P = 0.116), median subsequent intervention rate(53.4% vs. 40.0%, P = 0.501)and median case charge(€5145 vs. €3473, P = 0.803) for the treatment with a second metal stent insertion compared to plastic stent insertion. In patients with survival time of more than three months,significantly more patients treated with plastic stents needed re-interventions than patients treated with second SEMS(93.3% vs. 57.1%, P = 0.037).Conclusions: In malignant biliary strictures, both plastic and metal stent insertions are feasible strategies for the treatment of occluded SEMS. Our data suggest that in palliative biliary stenting, patients especially those with longer expected survival might benefit from second SEMS insertion. Careful patient selection is important to ensure a proper decision for either management strategy.     

The glider balloon: A useful device for the treatment of bifurcation lesions

Background

Final kissing balloon dilatation (FKBD) is a recommended final step in case of treatment of bifurcation lesions by two stents approaches. Furthermore, dilatation of the side branch (SB) may be necessary following main vessel (MV) stenting. Occasionally, recrossing the stent struts with a balloon is hampered because the tip hits a stent strut.

Methods

The Glider (TriReme Medical, Pleasanton, CA) is a dedicated balloon designed for crossing through struts of deployed stents toward a SB. From October 2010 to January 2012, FKBD was attempted in 236 consecutive bifurcation lesions treated in our Institution. FKBD was successfully performed by conventional balloon catheters in 221 (93.5%) lesions (Conventional group). In the remaining 15 (6.5%) lesions, where a conventional balloon failed to cross the stent strut, the Glider balloon was attempted (Glider group).

Results

The angle beta (between the axis of the MV after the branch point and the SB axis at the point of divergence) was wider in the Glider group (83 ± 17° versus 65 ± 27°; p = 0.032). A trend toward an higher rate of the true bifurcation lesions was observed in the Glider group (93% versus 70.5%; p = 0.07). The Glider balloon successfully crossed through MV stent struts toward a SB in 12 patients (80%), whereas failed in the remaining 3 patients.

Conclusions

The Glider balloon represents an unique bail-out device which offers an effective rescue strategy for recrossing stent struts during complex bifurcation stenting.     

Clinical outcomes of patients treated with Nobori biolimus-eluting stent: Meta-analysis of randomized trials

Backgrounds

The Nobori is a new-generation, biodegradable-polymer coated, biolimus-eluting stent (BES) that has recently been investigated in several randomized trials with inconsistent results. The aim of this study was to assess the efficacy and safety of Nobori BES versus other drug-eluting stents (DES) in patients treated with percutaneous coronary intervention (PCI).

Methods

We undertook a meta-analysis of randomized trials investigating Nobori BES versus other DES. Primary efficacy and safety outcomes were target lesion revascularization (TLR) and definite/probable stent thrombosis (ST), respectively. Secondary outcomes were the composite of cardiac death/myocardial infarction (MI)/target vessel revascularization (TVR), MI and death.

Results

A total of 9114 PCI-patients randomly received Nobori BES (n = 5080) or other DES (n = 4034). This latter group comprised patients receiving everolimus- (n = 2533), sirolimus- (n = 1376) or paclitaxel-eluting stents (n = 125). Median follow-up was 11 months [interquartile range 9–12]. The Nobori BES versus other DES showed comparable risk of TLR (odds ratio [95% confidence interval] = 0.91 [0.57–1.46], p = 0.71). There was significant heterogeneity across trials due to significant lower TLR risk with Nobori BES versus paclitaxel-eluting stent (0.32 [0.10–0.98], p = 0.046; p for interaction = 0.009). Nobori BES versus other DES showed comparable risk of definite/probable ST (1.40 [0.66–2.97], p = 0.39), cardiac death/MI/TVR (1.05 [0.88–1.25], p = 0.59), MI (1.13 [0.87–1.48], p = 0.37) and death (1.09 [0.81–1.48], p = 0.56).

Conclusions

Nobori BES has comparable efficacy with other limus-eluting stents at 1-year follow-up. There is no difference in terms of safety profile between these stent platforms.     

Bilateral Metal Stents for Hilar Biliary Obstruction Using a 6Fr Delivery System: Outcomes Following Bilateral and Side-by-Side Stent Deployment

Background and Study Aim

Controversy exists on optimal endoscopic management for palliation of malignant hilar obstruction, with advocates for metal “side-by-side” (SBS) and “stent-in-stent” (SIS) techniques. We sought to evaluate the technical feasibility, efficacy, and outcomes of bilateral biliary self-expanding metal stents (SEMS) for treatment of malignant hilar obstruction using a stent with a 6Fr delivery system.

Patients and Methods

This was a single-center, retrospective review of all patients who underwent bilateral placement of Zilver^® biliary SEMS for malignant hilar obstruction from January 2010 to August 2012. Patients underwent endoscopic retrograde cholangiopancreatography with placement of stents using either the SIS or SBS stent techniques.

Results

Twenty-four patients (19 men, mean age 63 years) underwent bilateral stenting for malignant hilar obstruction during the study period. Seventeen and seven patients underwent the SBS and SIS technique, respectively. Cholangiocarcinoma (n = 14) was the most common cause of hilar obstruction. Initial technical success was achieved in 24/24 (100 %) of patients; however, 12 (50 %) patients required re-intervention during the study period (median 98 days). Comparison of the SBS and SIS groups revealed no statistical difference with respect to need for re-intervention (P = 0.31), successful re-intervention (P = 0.60), or procedural length (P = 0.89).

Conclusions

Use of bilateral Zilver^® SEMS in either the SBS or SIS configuration is safe, technically feasible, and effective for drainage of malignant hilar obstruction; however, duration of stent patency and procedure-free survival remain variable.     

Comparisons of detailed arterial healing response at seven months following implantation of an everolimus- or sirolimus-eluting stent in patients with ST-segment elevation myocardial infarction

Background

The difference of arterial healing response following everolimus-eluting stent (EES) or sirolimus-eluting stent (SES) implantation in patients with ST-segment elevated myocardial infarction (STEMI) has not been compared in detail.

Methods

Thirty-five patients with STEMI were randomly implanted with an EES or SES (23 EES, 12 SES). At seven months, neointimal thickness (NIT) and strut malapposition were evaluated by optical coherence tomography (OCT) and the grade and heterogeneity of neointimal coverage (NIC) and development of intra-stent thrombi were evaluated by angioscopy.

Results

No significant differences were noted in clinical events experienced by the two groups, although one patient with an EES died following a papillary muscle rupture and one patient with a SES experienced sub-acute stent thrombosis. On OCT, although the EES implants showed a greater NIT than the SES implants (94.8 ± 88.8 μm vs 65.6 ± 63.3 μm, P < 0.0001), both the EES and SES showed an excellent suppression of neointimal proliferation in the culprit lesion of STEMI. The frequency of uncovered and malapposed struts of EES was significantly lower than that of SES (2.7% vs. 15.7%, P < 0.0001, 0.7% vs. 2.3%, P < 0.0001, respectively). The ratio of stents fully covered with neointima of EES group was significantly higher than that of SES group (P = 0.04). Angioscopic analysis also showed greater dominant NIC grade with homogenous NIC in EES than in SES (P = 0.03, P = 0.0002, respectively). The incidence of massive intra-stent thrombus of EES was lower than that of SES (P = 0.05).

Conclusion

For patients with STEMI, EES may promote better arterial healing response than SES.     

Use of covered Cheatham-Platinum stents in congenital heart disease

Background

Controversy remains regarding the use of covered stents in congenital heart disease (CHD). We evaluate the possibilities and safety of covered Cheatham-Platinum (CCP) stents in CHD.

Methods

Single-center retrospective CHD-database study of all CCP stents, 2003–2012. Three study groups: aortic coarctation (CoA), right ventricular outflow tract pre-stenting for percutaneous revalvulation (RVOT), and miscellaneous. Continuous data expressed as median (range).

Results

114 CCP stents in 105 patients, age 16.8 years (4.2–71.2).CoA group: 54 CCP stents in 51 patients: 3/54 for aneurysm exclusion, in 51/54 covering used “prophylactically” because of increased risk for vessel tear. Overall, CCP stenting increased the coarctation diameter from 6 mm (0–15) to 15 mm (10–20) (p < 0.001).RVOT group: 39 CCP stents in 37 patients (34 with RVOT graft, 3 with transannular patch): the graft lumen had shrunken from nominal 21 mm (10–26) to 13 mm (5–22); with the CCP stent the RVOT was redilated to 22 mm (16–26, p < 0.001 vs stenosis).Miscellaneous group: 21 CCP stents in 17 patients: closure of Fontan-circuit fenestration (n = 5), restoration of superior caval vein (n = 2) or pulmonary artery (n = 3) patency, relief of supra-pulmonary stenosis (n = 2), exclusion of aberrant pulmonary arteries (n = 1), cavopulmonary conduit expansion (n = 2), Blalock–Taussig shunt flow reduction (n = 1), and defibrillator lead protection from sharp stents (n = 1). Hybrid procedures performed in 3/17 patients. CCP stent was used as rescue treatment in 2/patients to seal iatrogenic bleeding.

Conclusion

CCP stents can safely be applied in CHD patients. The covering allows adequate sealing of existing or expected tears, thereby increasing the safety margin with more complete dilation.     

Novel self-expandable,stent-based transcatheter pulmonic valve: A preclinical animal study

Background

Because transcatheter implantation of pulmonary valve is indicated for limited-size dysfunctional right ventricular outflow tract only as a balloon-expandable stent, we investigated the feasibility of a large-diameter self-expandable valved stent and the durability of the valve after > 6 months.

Methods

We made a nitinol-wire-based, self-expandable valved stent with leaflets made from porcine pericardium. The porcine pericardium was treated with α-galactosidase, glutaraldehyde, and glycine after decellularization. After cutting the inguinal or cervical area, we implanted a valved stent in 12 sheep through the femoral or jugular vein by using an 18-Fr delivery catheter, controlling the catheter handles and hook block under fluoroscopic and echocardiographic guidance.

Results

The mean body weight of sheep was 43.9 kg. We successfully implanted valved stents (diameter: 24 mm in 7 sheep, 26 mm in 5 sheep) in good position in 8 sheep, in the main pulmonary artery (PA) in 2 sheep, and in the right ventricular outlet tract (RVOT) in 2 sheep. We sacrificed 8 sheep (6 sheep in good position, 1 sheep in the main PA, and 1 sheep in the RVOT) after > 6 months. Five of the 6 sheep implanted in good position showed well-preserved valve morphology at the time of sacrifice. Histologic findings after routine sacrifice showed well-maintained collagen wave structure and no visible calcification in all explanted valve leaflets.

Conclusions

Transcatheter implantation of a nitinol-wire-based, self-expandable valved stent in the pulmonic valve was feasible, and stents implanted in good position showed well-preserved valve leaflets with functional competence in the mid-term results.     

Optical coherence tomography and histopathological assessment of delayed arterial healing after drug-eluting stent implant in a pig coronary model

Background

Delayed healing, such as persistent inflammation and fibrin deposition, and vascular dysfunction after drug-eluting stent has been reported. Histological validation of coronary optical coherence tomography (OCT) morphology has not yet been done.

Methods

Sirolimus eluting stents (SES, n = 8) and bare metal stents (BMS n = 8) were implanted in pig coronary arteries. One month after implantation, an acetylcholine challenge test and OCT were performed. The OCT texture pattern of the neointima was classified into one of the three categories; Layered type, Homo type, and Hetero type. Hearts were harvested for histopathological scoring of inflammation and intramural thrombus.

Results

Inflammation and intramural thrombus scores were higher in the Hetero type than in the Layered type and Homo type. OCT intensity of the Homo type was higher than that of the Layered type and Hetero type. Most SES were of the Hetero type. Conversely, most BMS were of the Homo type. SES exhibited higher inflammation and intramural thrombus than BMS (1.72 ± 0.89 vs 1.00 ± 0.00, P = 0.0003, 2.39 ± 0.70 vs 0.92 ± 0.28, P < 0.001 respectively). After acetylcholine injection, the diameter change was 4.31 ± 4.80% for SES versus − 3.68 ± 6.81% for BMS (P = 0.024).

Conclusions

The Hetero type texture pattern in OCT images was associated with histological inflammation and intramural thrombus predominantly found in SES, and is related to endothelial dysfunction.     

Preoperative Colonoscopy for Detection of Synchronous Neoplasms after Insertion of Self-Expandable Metal Stents in Occlusive Colorectal Cancer: Comparison of Covered and Uncovered Stents

Background/Aims

In patients with occlusive colorectal cancers, a complete preoperative evaluation of the colon proximal to the obstruction is often impossible. We aimed to evaluate the feasibility of preoperative colonoscopy after stent placement and to determine whether the success rate of colonoscopy differs between covered and uncovered stents.

Methods

Seventy-three patients with malignant colorectal obstruction were enrolled prospectively. In patients with a resectable cancer, a preoperative colonoscopy was performed after insertion of a self-expandable metal stent (SEMS). The success rate of complete preoperative colonoscopy was compared between covered and uncovered stents.

Results

Forty-five of 73 patients who underwent stent placement had a resectable cancer (61.6%). A complete preoperative colonoscopy was possible in 40 of 45 patients (88.9%). The success rate of complete preoperative colonoscopy was significantly lower in the covered-stent group when the obstructing mass lesion was located in the sigmoid colon (p=0.024). Synchronous cancer was detected in one patient (2.2%). Stent migration was observed in four patients with a covered stent.

Conclusions

A preoperative complete colonoscopy after SEMS placement was feasible and safe in most patients with malignant colorectal obstruction. Uncovered stents seem to have more advantages than covered stents in preoperative colonoscopy proximal to the obstruction.