Balloon-expandable Stent Research Articles

Use of the Szabo Technique to Guide Accurate Stent Placement at the Vertebral Artery Ostium

To evaluate the Szabo technique in stenting at the vertebral artery ostium. Between 2010 and 2011, 26 patients (21 men; mean age 67 years) with symptomatic vertebral artery ostial stenosis >60% were treated. Under distal filter protection, a 0.014-inch guidewire was introduced in the ipsilateral subclavian artery as the marker wire for the Szabo technique. The balloon-expandable paclitaxel-embedded Yinyi stent was mounted on the filter's guidewire in a monorail configuration. One strut segment only of the last stent cell was gently flared by forceps, and the outer end of the marker wire was introduced through the flared strut of the stent. The lifted strut was then crimped back into place. Holding the two wires together, the stent/balloon system was gently advanced into the ostial lesion until the marker wire stopped advancing and resistance was appreciated. The stent was deployed at 6 atmospheres, after which the balloon was deflated to 2 to 4 atmospheres, the marker wire was withdrawn, and the stent was postdilated at a high pressure (10-12 atmospheres) after withdrawing the balloon one half to one third outside of the stent to ensure that the protruding strut was flush against the wall of the subclavian artery. The technical success rate was 100% with accurate stent deployment. The mean degree of stenosis reduced from 84.5%±6.1% to 6.2%±3.1%. Symptoms were resolved in 20 cases and were improved in 6 cases with prior stroke. No obvious in-stent restenosis was revealed by imaging at 12.0±2.2 months. No procedure-related stroke or transient ischemic attacks occurred at a follow-up for 24.0±3.7 months. The Szabo technique is safe and effective in guiding accurate placement of the Yinyi stent at the vertebral artery ostium, which may help lower restenosis rates.

Midterm Outcomes of Covered Versus Bare-Metal Balloon-Expandable Stents for Aortoiliac Occlusive Disease

Randomized trials and registries suggest that covered balloon expandable stents have better short-term patency than bare metal (BM) balloon expandable stents in the treatment of common iliac artery disease. This study was performed to evaluate midterm outcomes of bare metal vs covered balloon expandable stents for treatment of aortoiliac (AI) occlusive disease. All AI endovascular interventions for symptomatic peripheral arterial occlusive disease performed at a single institution from 2006-2012 were reviewed. Patients that underwent stent placement in the common iliac arterial segment were included in the analysis. Demographic data, TransAtlantic Inter-Societal Classification (TASC), stent type, patency, and all reinterventions for each limb were compared. 188 procedures in 124 patients were performed for treatment of de novo distal aorta and/or common iliac artery stenosis. Bare metal balloon expandable stents were used in 135 arteries, and covered balloon expandable stents were used in 53 arteries. There was no difference in age, gender, or TASC classification between the two groups. Table I. Median follow up was 1.7 years (IQR, 0.6-3.0). There was no difference in overall primary or primary assisted patency between the two groups. Table II. Secondary patency was significantly better in the covered stent group, however, common Iliac arteries treated with covered stents were more likely at 1 year and beyond to require repeat aortoiliac intervention (HR, 2.6; 95% CI, 1.13-6.0; P = .02; Fig). TASC classification did not predict need for reintervention in either group. In the current study, covered stents have improved secondary patency over bare metal stents for treatment of AI occlusive disease, at the expense of increased reinterventions. The difference in secondary patency may be due to more focal, edge restenosis in covered stents vs diffuse restenosis in bare metal stents.Table IDemographic characteristics of treated lesionsOverallBare metalCoveredP valueAge (mean ± SD)64 ± 1164 ± 1265 ± 11.5TASC A (%)54 (45)39 (43)15 (52).57TASC B56 (30)41 (30)15 (28).99TASC C41 (22)30 (22)11 (21).98TASC D36 (19)24 (18)12 (23).58 Open table in a new tab Table IIPatency of treated lesionsn = 188OverallBare metalCoveredP valuePrimary patency (%)121 (75)86 (75)35 (74).99Primary assisted patency136 (84)93 (82)43 (91).18Secondary patency140 (87)94 (82)46 (98).02 Open table in a new tab

Numerical fatigue life assessment of cardiovascular stents: A two-scale plasticity-damage model

Cardiovascular disease has become a major global health care problem in the last decades. To tackle this problem, the use of cardiovascular stents has been considered a promising and effective approach. Numerical simulations to evaluate the in vivo behavior of stents are becoming more and more important to assess potential failures. As the material failure of a stent device has been often associated with fatigue issues, numerical approaches for fatigue life assessment of stents have gained special interest in the engineering community. Numerical fatigue life predictions can be used to modify the design and prevent failure without making and testing numerous physical devices, thus preventing from undesired fatigue failures. We present a numerical fatigue life model for the analysis of cardiovascular balloon-expandable stainless steel stents that can hopefully provide useful information either to be used for product improvement or for clinicians to make life-saving decisions. This model incorporates a two-scale continuum damage mechanics model and the so-called Soderberg fatigue failure criterion. We provide numerical results for both Palmaz-Schatz and Cypher stent designs and demonstrate that a good agreement is found between the numerical and the available experimental results.

Computed Tomographic Imaging of Transcatheter Aortic Valve Replacement for Prediction and Prevention of Procedural Complications

Senile calcific aortic stenosis (AS) is the most common acquired valvular heart disease with an increasing prevalence attributable to an aging population. Survival is poor in patients with severe or critical AS, chiefly after the onset of symptomology that primarily includes angina, dyspnea, or syncope. On the onset of symptoms, mortality occurs at very high rates during the ensuing 2 to 3 years.1 Until recently, surgical aortic valve replacement represented the sole therapy that definitive reduced mortality and morbidity in patients with severe symptomatic AS, with medical therapy generally ineffective of these patients. Given the advanced age commonly associated with severe AS, a high proportion of these patients are denied surgical intervention because of multiple comorbidities and excessively high surgical risk.2 Recently, transcatheter aortic valve replacement (TAVR) has emerged as a novel disruptive technology that serves an alternative therapy to surgical AVR and has been shown to be an effective therapy in nonoperable and high-risk patients with severe symptomatic AS.3,4 TAVR was first described in humans by Cribier et al in 20025 by a transvenous approach delivered in an antegrade fashion. This technique requires a transseptal puncture and passage of the aortic stent valve across the mitral valve to the aortic position. Subsequently, array of alternative transvascular approaches have arisen, including transfemoral, transaortic, trans-subclavian, and aortic methods. Of these, the retrograde transarterial approach through the femoral artery, developed by Webb et al,6 has been the commonly used approach, with >60 000 such procedures performed worldwide to date. To date, the global experience with TAVR as documented in both single and multicenter registries as well as through multicenter trials have shown good clinical outcomes with improvement in hemodynamic and clinical status, establishing TAVR to be a feasible alternative therapy to traditional surgical aortic valve …

Endovascular Approach for Peripheral Arterial Injuries

In appropriate situations, treatment of arterial injuries with stent grafts decreases operative time, estimated blood loss, and iatrogenic complications when compared with open treatment. The purpose of this study was to describe the recent experience and outcomes of this technique in a large tertiary hospital. The medical records of 16 patients with peripheral arterial injuries were analyzed in a retrospective single-institution review. Injuries were caused by trauma in 6 patients (38%), iatrogeny during vascular access in 6 (38%), and complications of open surgical procedures in 4 (25%). The subclavian-axillary segment was involved in 5 cases (31%), femoropopliteal artery in 5 (31%), carotid artery in 3 (19%), and iliac arteries in another 3 (19%). Clinical presentation of the injury was pseudoaneurysm in 8 cases (50%), arteriovenous fistula (AVF) in 3 (19%), bleeding in 3 (19%), and pseudoaneurysm associated with AVF in 2 (13%). All patients were hemodynamically stable at evaluation, and were treated with balloon-expanding or self-expanding stent grafts. All patients were followed up with a duplex scan, with a mean follow-up time of 17.3 months. No deaths or amputations occurred. Four patients (25%) returned with occluded stent grafts. Among them, 3 presented with mild or no symptoms. One patient was treated with open vascular bypass to treat limiting-arm symptoms. Treating penetrating arterial injuries with stent grafts was shown to be safe and effective.

Intravascular ultrasound comparison of the self‐expanding sideguard stent in the side branch versus a balloon‐expandable stent in the main vessel to assess mechanisms of acute lumen gain in bifurcation lesions

We compared the mechanisms of lumen gain after Cappella Sideguard (CS) side branch (SB) bifurcation stent deployment versus a balloon-expandable stent in the corresponding main vessel (MV). The novel CS SB bifurcation stent is a self-expanding, thin-strut, nitinol device with anatomic flaring at the SB ostium. In 28 bifurcation lesions, intravascular ultrasound imaging of both the SB and the MV was performed both pre- and postintervention; vessel and lumen areas were measured every 1 mm over a 5 mm segment beginning at the carina. Although minimum lumen area (MLA) within the distal 5 mm segment beginning at the carina increased from 2.8 ± 1.3 mm(2) to 3.8 ± 1.1 mm(2), P < 0.001, in the SB and from 3.4 ± 1.4 mm(2) to 6.0 ± 1.1 mm(2), P < 0.001, in the MV, stent expansion (minimum stent area/distal reference lumen area) was significantly less in the SB compared with the MV (77.8 ± 21.3% vs. 91.6 ± 18.4%, P = 0.02). Post stenting, the MLA site was located at the carina more frequently in the SB (85.7%) than in the MV (60.7%), P = 0.04. Plaque volume in the 5 mm proximal to carina in the MV tended to decrease, whereas plaque volume in the SB increased slightly with no change in overall plaque volume in the 5-mm-long segment distal to the carina in the MV, suggesting plaque shift from the proximal MV to the SB. Acute CS lumen gain is less than the lumen gain of a balloon-expandable stent in the MV because of less aggressive acute expansion and/or the plaque shift from the proximal MV to the SB.

Morphology of the patent ductus arteriosus does not preclude successful patent ductus arteriosus stent implantation in high‐risk patients undergoing hybrid stage I palliation: Recommendations to optimize ductal stent positioning

To describe patent ductus arteriosus (PDA) stenting regardless of ductal morphology in high risk patients with hypoplast physiology undergoing hybrid stage I palliation (PDA stenting and placement of bilateral pulmonary artery bands). Hybrid palliation is an accepted alternative for patients with hypoplastic left heart syndrome. Patients weighing less than 2.5 kg, history of prematurity, intracranial hemorrhage, and chromosomal abnormality belong to a high-risk group who otherwise might not be ideal candidates for traditional surgical repair (Norwood Operation). Between May 2005 and February 2013, a series of 13 high-risk patients with hypoplast physiology with varying types of ductal morphology underwent PDA stenting as part of hybrid stage I palliation. Three major types of ductal morphology were identified: (1) short and semi horizontal, (2) long and semi horizontal, and (3) tortuous. All patients underwent successful PDA stenting. One patient developed proximal coarctation from inadequate coverage of the pulmonary end of the PDA and was successfully treated with a balloon expandable stent 69 days after the initial procedure. Mid- to long-term follow-up indicates that PDA stents remain widely patent regardless of ductal morphology until comprehensive stage II repair.

Migración de stent implantado en la arteria pulmonar en un paciente con tetralogía de Fallot

Tetralogy of Fallot is a congenital heart disease that accounts for 11-13% of the congenital cardiomyopathies. Stenosis and hyperplasia of the pulmonary arteries occur in a high proportion of them as this disease causes a native stenosis of the pulmonary branch, which can be surgically repaired with a stent. The use of balloon expandable intravascular stents is an alternative technique to further surgery in patients with congenital heart diseases. However, despite the gradual increase in their use, the limited number of procedures, combined with the wide anatomical variability and different characteristics of these patients, even in expert hands, stent implants are associated with a not inconsiderable incidence of complications. These are not always obvious and often require performing surgery in patients who have already had multiple interventions, thus increasing the complexity and the risk.

Antegrade In Situ Stent-Graft Fenestration for the Renal Artery Following Inadvertent Coverage During EVAR

To report the use of antegrade in situ fenestration as a bailout technique to rescue a renal artery after inadvertent coverage during endovascular aneurysm repair (EVAR). The technique is demonstrated in a patient with a 6-cm infrarenal abdominal aortic aneurysm (AAA) and a short, angulated proximal neck. A type I endoleak persisted on completion angiography after implantation of a bifurcated Zenith stent-graft despite dilation with a compliant balloon. A Giant Palmaz stent mounted on a large compliant balloon successfully resolved the endoleak. After placing the stent, the left renal artery was covered completely by the main aortic graft material, leading to only marginal opacification on angiography. To preserve flow to the renal artery, a transseptal sheath and transseptal needle were introduced from the right femoral artery and used to puncture the abdominal stent-graft antegrade at the site of the left renal artery. A 0.018-inch guidewire could then be introduced into the left renal artery; following a number of maneuvers, a balloon-expandable stent was placed through the fenestration into the target vessel. On computed tomographic angiography 4 days postoperatively, the AAA remained excluded and both renal arteries were patent, with all side branches fully preserved. Renal function was completely restored. Antegrade in situ fenestration can facilitate immediate revascularization of inadvertently covered side branches in EVAR using a transseptal sheath and needle. If the anatomical features are supportive, antegrade in situ fenestration can be a useful bailout technique.

Role of Balloon-Expandable Stents in Intracranial Atherosclerotic Disease in a Series of 182 Patients

To demonstrate the safety and efficacy of balloon-expandable intracranial stents in patients with intracranial atherosclerotic lesions (>70% stenosis) who were symptomatic despite being on optimum medical therapy. Between April 2004 and May 2012, 182 patients underwent intracranial stenting in our institution. All patients had symptoms despite being on optimum medical therapy. Clinical follow-up was done at 1, 3, 6, and 12 months. Angiographic follow-up was done at 1 year in 121 patients. Technical success was achieved in 97.44% of the cases. The incidence of all strokes at 1 month after procedure was 11 (5.64%), of which 2 (1.02%) were major, both related to stent thrombosis not responding to tirofiban, and 9 (4.61%) were minor. Periprocedural minor stroke was seen in 9 patients. There were 2 deaths in our study (mortality=1.09%). Treatment of intracranial atherosclerotic disease with balloon-expandable intracranial stents is a safe and effective method with acceptable adverse events, especially in patients who failed medical therapy and were symptomatic despite being on optimum medical therapy.

Endovascular reconstruction of iliac artery bifurcation atherosclerotic disease with the kissing technique

A 71-year-old male patient with severe left buttock and lower-extremity claudication due to iliac artery bifurcation stenoses was referred to our institution for endovascular treatment. A 'kissing' technique was used in order to dilate the proximal parts of both internal and external iliac arteries and avoid compromization of the internal iliac artery during proximal external iliac artery stenting. A balloon expandable stent was inserted via a left ipsilateral retrograde access to the narrowed origin of the left external iliacartery and a balloon catheter via a right contralateral access inside the origin of the left internal iliac artery. Simultaneous balloons inflation restored full patency of both vessels. Twelve months later the patient is doing well, free of buttock or lower-extremity claudication symptoms. For iliac artery bifurcation atherosclerotic disease, endovascular repair with the 'kissing' technique can achieve a complete bifurcation reconstruction offering significant clinical benefit in selected patients.

Stent outcomes for infrapopliteal arterial occlusive disease

This study aimed to determine if the different stent types used in the treatment of infrapopliteal arterial occlusive disease provide any significant advantage over one another at 6 and 12-month follow-up. Consecutive patients undergoing stenting of infrapopliteal lesions were enrolled into a non-randomised prospective registry and followed-up for 1 year. Outcome measures included binary restenosis, target lesion revascularisation, major amputation, and change in Rutherford-Becker score and ankle-brachial index (ABI).Thirty-three patients were enrolled including four patients with bilateral disease. There were 20 target vessels in the drug-eluting stent (DES) group, 13 target vessels in the balloon-expandable bare metal stent (BE-BMS) group and 14 target vessels in the self expandableb are metal stent (SE-BMS) group. Most of the patients in the study were octogenarians except in the SE-BMS group where the mean age was 73 ± 9 years. At 12 months, seven patients had died (DES = 6, BE-BMS = 1) from cardiac and cancer-related diseases. In-stent and peri-stent binary restenosis were non-statistically different between all three groups. There was a nonstatistically significant trend towards higher target vessel revascularisation in the BE-BMS group. Survival curves in all stent types demonstrated restenosis to occur within the first 6 months post-procedure. There was no significant difference in the change in Rutherford-Becker score or ABI between the groups. No major limb amputations occurred during the 12-month period. In conclusion,we did not detect a significant difference in stent performance between the different stent types used to treat infrapopliteal arterial occlusive disease. The choice of stent did not seem to affect patient survival or major amputation-free survival at 1-year follow-up.

Design optimization of balloon-expandable coronary stent

To prevent the dogboning effect of stent implantation (i.e. the ends of a stent opening first during expansion), an adaptive optimization method based on the kriging surrogate model is proposed to ...

Response to Letters Regarding Article, “Cerebral Embolization During Transcatheter Aortic Valve Implantation: A Transcranial Doppler Study”

The importance of cerebral embolization as the main cause of periprocedural stroke during transcatheter aortic valve implantation has recently been demonstrated. Erdoes and colleagues1 have reported high-intensity transient signals as surrogates for microemboli during all phases of the procedure, predominantly during valve implantation, with no difference between transfemoral and transapical access and slightly more microemboli with the self-expandable than with the balloon-expandable stent valve. We not only confirmed their findings but extended them to highlight the calcified aortic valve as the main source of emboli and mean transaortic gradient at baseline, reflecting aortic stenosis severity, as an independent predictor for the frequency of high-intensity transient signals.2 We agree that a “minimal-touch technique”1,3 with modest manipulation of the aortic arch and, more important, the aortic valve is key to minimizing periprocedural embolism and stroke. We also agree that a minimal-touch principle should be extended to the brachiocephalic and carotid arteries, which are regularly atherosclerotic in the elderly …

Crimping and deployment of balloon-expandable valved stents are responsible for the increase in the hydraulic conductance of leaflets

Leaflet injury has been documented to occur during the deployment of valved stents (VSs). The pathological aspects, however, of this injury are difficult to quantify. Conversely, the hydraulic conductance of a (pericardial) membrane may be easily determined. The impact of crimping and deployment of VS on this parameter was therefore investigated. Bovine pericardial square (25 × 25 mm) patches were placed within a pressure chamber and their hydraulic conductance was determined. The influence of the pressure gradient and tissue thickness on this parameter was analysed. Six balloon-expandable VS were constructed. The hydraulic conductance of their bovine pericardial leaflets was determined before and after VS crimping and deployment in four of them. Pericardial leaflets of non-crimped VS were used as controls. Hydraulic conductance increased insignificantly with the pressure level within the chamber: from 128 ± 26.9 ml/h/m(2)/mmHg at a pressure of 50 mmHg to 232.3 ± 51.9 ml/h/m(2)/mmHg at a pressure of 250 mmHg (P = 0.117). Hydraulic conductance was not correlated to pericardial thickness, for thickness measurements ranging from 0.34 to 0.76 mm. The hydraulic conductance of VS leaflets significantly increased immediately after crimping from 45.2 ± 7.6 to 667.9.0 ± 527.2 ml/h/m(2)/mmHg (P < 0.001). This increase was still observed 24 h after VS deployment. No change in hydraulic conductance occurred in the control group. The determination of the hydraulic conductance of pericardial patches was easy to perform, reproducible and not influenced by tissue thickness. The hydraulic conductance of pericardial leaflets dramatically increased after VS crimping and deployment. This parameter might be, in the future, a useful noninvasive tool in studying leaflet trauma.

Placement of balloon-expandable stents in coarcation of the aorta: Initial results and short-term follow up

We report preliminary result and short term follow up (up to 5 years)of balloon-expandable stents for the coarctation of the aorta (COA). Using balloon-expandable stents gained acceptance over the past years, as a modality of treatment for COA. However, use of these stents may create disruption of the aortic wall or aneurysm at the stents end points. Our experience using Palmaz stent in half of the patients mounted on a balloon dilatation catheter. The rest of the patients received Covered CP Stent. All patients had significant improvement without any complications. Twenty five patents with mean age 18 years range from 9 to 45 with COA underwent stent implantation. Nine patients were diagnosed with native COA and 16 had previous surgical, balloon dilatation or both, to relieve their coarcation; but had residual/recurrent gradient. A femoral vessels access performed for such procedure and angio-grams were obtained pre and post stent implantation. BP was continuously monitored during the procedure. All patients were maintained on aspirin for at least 6 months post procedure. Immediately after stent implantation the peak systolic gradient (mean (SD)) fell from 35 mm Hg (15.6) to 3.8 (4.3) (mm Hg). ( p < 0.05). The diameter of the stenotic lesion increased from 6.5 (3.0) to13.5 (3.0) mm ( p < 0.05). There were no deaths or procedure related complications. Measured one day after stent placement, the descending aorta velocity dropped from (mean (SD)) 3.7 (0.58) m/s to 2.3 (0.6) m/s. ( p < 0.05). At median follow up of 24 months, the clinical gradient dropped from (mean (SD)) 36 (18) mm Hg pre intervention to 4 (9) p < 0.05) mm Hg. Seven patient (28%) required re-dilatation at a later stage for re-stenosis. The average systolic and diastolic blood pressure at follow up was at the 5th percentile. Nine patients (28%) were still on antihypertensive medications compare to 13 patients (52%) at the time of stent implantation. Stent implantation for the treatment of coarctation of the aorta appears to have very low morbidity and mortality, and reasonable intermediate term results. A long term follow up is needed.

Educational Exhibit Abstract No. 354 - Primary placement of a constrained transjugular intrahepatic portosystemic shunt: how we do it

Learning Objectives Three methods for placement of a primary constrained transjugular intrahepatic portosystemic shunt (TIPS) will be reviewed. Background TIPS creation is often complicated by hepatic encephalopathy. Medical management fails in approximately 5-10% of cases. In those patients, TIPS revision may be required by creating a flow-limiting stent using a variety of methods. To avoid the complication of hepatic encephalopathy, however, we occasionally place primary constrained stents during the initial TIPS creation, particularly if the indication for TIPS is refractory ascites. Clinical Findings/Procedure Details We take one of three approaches to creating a primary constrained TIPS. In one approach, a self-expanding 10 mm Gore-Viatorr stent graft is deployed and a 5-0 Prolene suture is tied around the midpoint. The modified graft is then crimped into a peel-away sheath and re-sterilized. After formation of the intrahepatic tract, the graft is deployed and balloon dilated. The suture creates a flow-limiting constriction which may be dilated and/or broken as needed to improve flow. Prolene is favored due to its high elasticity, which allows for balloon expansion. Another approach involves deploying the stent graft through a balloon-expandable bare metal stent. After accessing the portal vein, we place a short 6-8 mm bare metal stent within the intrahepatic tract. Once this stent is in place, the Viatorr stent graft is deployed within it and the entire assembly is dilated to the diameter needed. The outer stent maintains a constriction in the inner stent graft due to its higher radial force, and can be dilated at a later time. In the third technique, a balloon-mounted Atrium iCast stent graft is placed on a 10-French sheath and a 4-0 absorbable suture is tied around its midpoint. This stent is then crimped onto a balloon and deployed, with the suture serving as the constriction point. Dilation can be done at a future time if needed. Conclusion and/or Teaching Points Creation of a primary constrained TIPS can be readily performed, enabling a degree of control over reduction of the portosystemic gradient both at initial TIPS creation and at follow up. Whether these techniques result in a reduction of hepatic encephalopathy requires further investigation.

Primary balloon-expandable covered stents vs. primary bare-stents for mesenteric ischemia: patency and clinical outcomes

Purpose To evaluate the anatomical and functional outcomes of primary balloon-expandable covered stents compared to primary balloon-expandable bare-stents for the endovascular management of chronic mesenteric ischemia. Materials and Methods A retrospective audit of patients undergoing primary endovascular management of mesenteric ischemia was performed (01/2006-12/2011). The cohort was divided into bare-metal stent group (BMG) and covered stent (0.035-inch platform, V-12, Atrium) group (CVG). Inferior mesenteric artery (IMA) arteries (none in CVG) and angioplasty alone (small sample size) were excluded. Patency per artery was determined by imaging follow-up and clinical success (patency by clinical response). Results 111 primary endovascular procedures were found (18 IMA excluded). Technical success of SMA and CAx arteries was 99% (n=110/111). An additional 7 arteries (2 SMA, 5 CAx) in 6 patients were excluded (angioplasty alone). The remainder was: 15 (12 SMA, 3 CAx) arteries in 14 patients (CVG) and 88 (64 SMA, 24 CAx) arteries in 75 patients (BMG). Clinical success per patient for BMG vs. CVG was 87% (n=65/75) vs. 79% (n=11/14) (P=0.3933), respectively. Primary unassisted patency at 6, 9, 12 and 24 months for CVG vs. BMG were: 100%+/-0, 100%+/-0, 100%+/-0, and 100%+/-0 vs. 93%+/-4, 81%+/-6, 74%+/-8, and 45%+/-11, respectively (P Conclusion In patients with mesenteric ischemia, balloon-expandable covered stents have improved patency compared to balloon-expandable bare stents in the celiac axis and superior mesenteric artery.

Incidence of in-stent re-stenosis with CATANIA Coronary Stent

The study sought to assess safety and efficacy of implantation of CATANIA Coronary Stent. CATANIA Coronary Stent is new stents coated with an inorganic, high molecular weight polymer Polyzene F. It is a flexible cobalt chromium balloon expandable stent. Polyzine-F was claimed to have low surface thrombogenicity, anti-inflammatory, bacterial resistance, and pro healing effects which result in low rate of stent thrombosis and in-stent re-stenosis (ISR) requiring short duration of dual anti platelet therapy. Catania is neither a BMS nor a DES but somewhat in between. This is a prospective, single center, observational cohort study of 33 patients with symptomatic ischemic heart disease with de novo, obstructive lesion of native coronary arteries. The patients were followed up at 12 months after the implantation for the symptoms and any new coronary events. Of the 33 patients, one patient died due to non cardiac cause, 4 patients were admitted with unstable angina and two patients with angina and positive stress test. The entire 6 patient had significant more than 70% ISR. The target lesion revascularization (TLR) at 12 months was 18.75% At one year follow up, The Catania stent was found to be associated with a significant ISR with TLR of 18.75%.

The Single-centre Experience of the Supra-arch Chimney Technique in Endovascular Repair of Type B Aortic Dissections

We summarised the data performed at our centre to evaluate the feasibility of the chimney technique in type B aortic dissections (ADs) with supra-aortic vessel involvement. From September 2006 to December 2011, 34 thoracic endovascular aortic repairs (TEVARs) for ADs were performed combined with reconstruction of the arch branches with chimney stents (innominate artery, IA, n = 3; left common carotid artery, LCCA, n = 8; left subclavian artery, LSA, n = 23). Indications for these chimney stents included an inadequate proximal landing zone (<1.5 cm); high surgical-risk patients who are not suitable for open repair or hybrid procedures; and emergent endovascular repair of ADs. The series consisted of 13 acute, 12 sub-acute and 9 chronic cases. The right common carotid-left common carotid-left subclavian artery bypasses were performed in the IA chimney cases to reserve an adequate cerebral perfusion from the LCCA and left vertebral artery, while the left common carotid-left subclavian artery bypasses were performed in the cases having dominant left vertebral arteries. All the TEVARs, chimney stents and bypasses were performed as a single stage. Follow-ups were performed at 3, 6 and 12 months, and yearly thereafter. Endografts were deployed in Zone 0 (n = 3, 9%), Zone 1 (n = 8, 24%) and Zone 2 (n = 23, 67%). Twenty-five (74%) balloon-expandable and 9 (26%) self-expanding stents were used, of which seven (21%) were covered and 27 (79%) were bare stents. The technical success rate was 82% (28/34). Immediate type I endoleaks were observed in five patients (5/34, 15%), all of which underwent bare chimney-stent repairs. Three self-expanding chimney stents were compressed by endografts and another balloon expandable stent was deployed inside the first one. Five patients underwent surgical bypasses (RCCA-LCCA-LSA, n = 3; LCCA-LSA, n = 2). Perioperative morbidity included one ST-elevation myocardial infarction. No perioperative death or stroke was observed. The mean follow-up was 16.3 months (range, 3-60 months). Primary patency was maintained in all the chimney stents as well as the surgical bypasses. No stent fracture or recurrent chimney-related endoleak was observed during the follow-up period. In repairs for type B ADs, the chimney technique provides a minimally invasive way of preserving flow to the arch branches combined with a favourable mid-term outcome. The bare stents seemed to be related to a higher probability of the immediate type I endoleaks. A balloon-expandable stent should be regarded as the first choice due to its greater radial strength.