Balloon-expandable Stent Research Articles

Focus on STENTYS® Xposition S Self-Apposing® stent: a review of available literature.

Percutaneous coronary interventions are the primary revascularization strategy for the vast majority of patients with coronary artery disease. Nevertheless, challenging settings still limit optimal results, especially in case of significant tapering, bifurcations or primary angioplasty in ST-segment elevation myocardial infarction. Stentys® Self-Apposing® stent was designed to improve strut apposition to the vessel wall and to adapt to difficult targets. The Xposition S is a sirolimus-eluting stent with a novel delivery system, to improve accurate positioning. Several studies compared the device with traditional balloon-expandable stents, showing better results in terms of malapposition reduction and a noninferiority in relation to procedural outcomes. Available data show good clinical results, but a direct comparison with balloon-expandable stents from large randomized trials is still lacking. Thus, the Stentys Xposition S can be an alternative to traditional stents in dedicated scenarios, but strong evidence from large randomized trials is needed to derive stronger recommendations.

Structural analysis of cyclically periodic rings and its application to the mechanics of balloon expandable stents

The performance of balloon expandable stents during deployment is usually assessed computationally. Most stents have a generic feature that entails wavy rings known as “crowns” which are interconnected via structures known as “bridges”. A mathematically exact analyses of such wavy rings would provide a benchmark to such computations and offer a clear insight into the deformation of stents. In the present work, an analytical model is developed to estimate the elasto-plastic response of a cylindrical periodic structure made of sinusoidal crowns interconnected by bridges. Two different interconnections are considered that give rise to two distinctive behaviours one of which is auxetic. Elastic-perfectly plastic material is considered. The apparent elasto-plastic response of the cylindrical structure is obtained in a closed-form by exploiting the periodicity along its longitudinal and the circumferential direction. A scaling ansatz is proposed that collapses nonlinear response data for different geometries into a family of master-curves. Such relationship suggests that the most efficient way to increase the apparent stiffness of the structure is to decrease the amplitude of the wavy crowns.

Five-Year Patency and its Predictors after Endovascular Therapy for Aortoiliac Occlusive Disease.

Aim: Although current guidelines recommend surgical revascularization as the first-line therapy for chronic total occlusion of the abdominal aorta (Leriche syndrome), endovascular therapy (EVT) has been increasingly utilized because of the development of new technologies and techniques. EVT has demonstrated durable midterm outcomes for aortoiliac occlusive disease (AIOD). Nonetheless, little is known regarding their long-term outcomes and predictors of restenosis.Methods: We retrospectively analyzed a multicenter database of 64 consecutive patients (age, 73 ± 10 years; 64% male; 22% critical limb ischemia) undergoing EVT for aortoiliac occlusive disease between September 2005 and March 2016. The outcome measures were primary and secondary patency, following EVT, calculated using the Kaplan–Meier method. Independent predictors associated with restenosis were assessed using Cox proportional hazard regression model.Results: Technical success was achieved in 61 patients (95%). In total, 214 stents (192 self-expandable stents, 22 balloon-expandable stents) were implanted. During the follow-up of 33 ± 28 months, 11 patients experienced loss of patency. The primary patency rates were 88%, 70%, and 70% at 1, 3, and 5 years, respectively. The secondary patency rates were 98%, 87%, and 77% at 1, 3, and 5 years, respectively. In Cox regression analysis, E-Luminexx stent use (in 29 patients, 48%) was associated with restenosis [hazard ratio, 4.41, P = 0.038].Conclusion: In this retrospective study, EVT for AIOD demonstrated favorable 5-year patency. E-Luminexx stent implantation was associated with restenosis in this population.

Combined Less-invasive Surgical and Endovascular Technique to Minimise Operative Trauma and Treat Excessive Aortoiliac Thrombotic Obliteration with Popliteo-crural Involvement and Acute Limb Ischaemia

This article demonstrates a less-invasive combined surgical and endovascular alternative approach in a case in which an excessive thrombotic formation in the infrarenal aorta caused occlusion of the iliac artery and the ipsilateral crural arteries. A 51-year-old man was admitted to the authors’ hospital with symptomatology of acute lower limb ischaemia. He had undergone endovascular treatment with placement of kissing stents in the common iliac arteries 2 years previously. A CT angiography scan revealed an extensive thrombus formation in the entire infrarenal aorta occluding the distal infrarenal aorta, the iliac artery and the crural arteries. He underwent a hybrid approach, with exposure of only the right common femoral artery and over-the-wire embolectomy of the infrarenal aorta and the iliac artery, and after the restoration of the inflow, an embolectomy of the peripheral vessels was carried out. To cover the residual aortic thrombus and to restore the severe in-stent restenosis of the previously deployed bare stents, three covered balloon-expandable stents were deployed in kissing technique. The patient was discharged on the fourth postoperative day with palpable peripheral pulses. Combined surgical and endovascular techniques minimise the operative trauma and length of hospital stay for the patient, successfully restoring the perfusion in a physiological manner.

Jotec E-Ventus BX Stent Graft Deployment in the FEVAR and Iliac Branch Device: Single Centre Experience.

Objectives: To evaluate the outcomes of the E-ventus BX balloon-expandable stent graft system (Jotec, Hechingen, Germany) implanted as bridging stent grafts during fenestrated endovascular aortic repair (FEVAR) and the iliac branch device (IBD) of complex aneurysms.Methods: This was a single centre retrospective analysis prospective study including all consecutive patients treated by FEVAR and the IBD performed with E-ventus BX stent grafts as bridging stents. Demographics of patients, the diameter and length of the bridging stent grafts, technical success, reinterventions, occlusions, post-operative events, and imaging (computed tomography [CT] scan and ultrasound) were prospectively collected in an electronic database. Follow-ups were performed with clinical assessment and a CT angiogram scan at four weeks after discharge followed by a duplex ultrasound every six months for two years and then a yearly duplex scan afterwards.Results: Between June 2015 and October 2017, 40 consecutive patients (three females) were treated with custom made fenestrated endografts and the iliac branch device for complex aneurysms, using the E-Ventus BX stent graft. All 82 E-Ventus BX stent grafts were successfully delivered and deployed. There was no in-hospital mortality. The early bridging stents patency rate was 97.6% (80 out of 82). The two-target vessel post-operative occlusion was secondary to kink of the renal stents and failure for re-lining of the renal artery. Of the two patients, only one needed permanent dialysis. On the late follow-up (after 30 days), two other patients demonstrated a renal stent occlusion, with one treated successfully with re-lining of the stent and the other patient treated conservatively. Neither of them needed permanent dialysis. A follow-up was maintained for 36 patients until April 2018 with a median follow-up of 18 months. All bridging stents E-Ventus BX stent grafts remained patent (78 out of 82, 95.1%).Conclusion: E-Ventus BX stent grafts used as bridging stents during FEVAR and the IBD are associated with favourable outcomes at the mid-term follow-up. Long-term follow-up is required to confirm these promising results.

Long-term outcomes of balloon-expandable bare stent as chimney stent in thoracic endovascular aortic repair for supra-aortic branches reconstruction.

To report the long-term outcomes of balloon-expandable bare stent (BEBS) as chimney stent (CS) in thoracic endovascular aortic repair (TEVAR) for supra-aortic branches reconstruction. A total of 33 patients with thoracic aortic diseases underwent TEVAR using BEBSs as CSs for supra-aortic branches reconstruction in our center from 2010 to 2015. The demographics and procedural details were prospectively collected and retrospectively reviewed. All patients were followed up at 1, 3, 6 months and every 1 year thereafter. Postoperative complications and long-term outcomes were recorded. The technical success rate was 100%. A total of 36 BEBSs were utilized as CSs to reconstruct the supra-aortic branches during TEVAR. The rate of immediate endoleak was 42.4% (14/33), including 12 (36.4%) type Ia endoleaks and 2 (6.1%) type II endoleaks. Two of type Ia endoleaks were managed by balloon dilation and disappeared, while the rest were left with close follow-up. Two type II endoleaks were embolized by coils and excluded by a plug, respectively. One patient (3.0%) died 2 days after the procedure due to the acute rupture of aortic dissection. The mean follow-up time was 61.8 (ranged from 12 to 102) months. The unmanaged 10 type Ia endoleaks were closely observed during the follow-up, of which 7 disappeared at 1 year and 1 disappeared at 2 years. The rest 2 type Ia endoleaks existed without further dilation of the aorta. One patient (3.0%) was re-intervened for the increased false lumen due to the distal residual tears. The long-term mortality was 9.1% (3/33). All CSs kept patent till the end of follow-up. No other complications were found. The balloon-expandable stent (BES) is a feasible choice as CS for supra-aortic branches reconstruction with long-term patency during TEVAR. However, BEBS may be related to a higher rate of early endoleak.

Chimney Endovascular Aneurysm Repair Using Endurant Stent-Grafts With Bare Balloon-Expandable Stents for Patients With Juxtarenal Aortic Aneurysms

Purpose: To evaluate the advantages of chimney endovascular aneurysm repair (chEVAR) using an Endurant stent-graft with uncovered balloon-expandable stents (BES) for patients with juxtarenal aortic aneurysms. Materials and Methods: Twenty-two patients (mean age 78.5±9.0 years; 13 men) who underwent chEVAR using Endurant and uncovered BES between January 2014 and December 2017 were analyzed retrospectively. The maximum aneurysm diameter was 59.1±11.9 mm, and the proximal neck length was 5.2±2.9 mm. Of the 22 cases, 9 (40%) involved proximal neck angulation and 9 (40%) had a conical neck. Single and double chimneys were performed using BES in 19 and 3 cases, respectively. In 2 cases, an additional self-expanding covered stent was used inside the uncovered BES. Results: The technical success was 91% (20/22) as 2 (9%) cases showed minor type Ia endoleak. No postoperative systemic complications or acute renal dysfunction (Acute Kidney Injury Network classification stage 2 or higher) were observed. The mean radiologic observation period was 16.1±9.6 months, and no aneurysm expansion (>5 mm) was observed during this time. The mean maximum aneurysm diameter decreased to 52.9±10.2 mm (p<0.001 vs preoperative), with an individual mean sac regression of 6.2±5.9 mm. Overall primary chimney stent patency was 100%. One of the 2 cases of intraoperative type Ia endoleak resolved at the 6-month imaging, and no new type Ia endoleaks developed in any cases at follow-up. No additional treatment- or aneurysm-related events were observed. Conclusion: Short-term outcomes of chEVAR using Endurant with uncovered BES have been favorable when covered stents were unavailable, and it can be useful for high-risk patients with juxtarenal aortic aneurysms.

Nanoglass‐based balloon expandable stents

Here, a prototypical metallic nanoglass is proposed as a new alloy for balloon expandable stents. Traditionally, the stainless steel SS 316L alloy has been used as a preferred material for this application due to its proper combination of mechanical properties, corrosion resistance, and biocompatibility. Recently, metallic glasses (MGs) have been considered as promising materials for biodevice applications. MGs often display outstanding mechanical properties superior to those of conventional metallic alloys and overcome some of the weaknesses of SS 316L, such as radiopacity, stainless steel allergy, and thrombosis-induced restenosis. However, commonly used monolithic MGs, which have an amorphous homogeneous microstructure, suffer from lack of ductility that is necessary for deployment of balloon expandable stents. In contrast, nanoglasses, that is, amorphous alloys with heterogeneous microstructure, exhibit enhanced ductility which makes them promising materials for balloon expandable stents. We evaluate the feasibility of a prototypical Zr64 Cu36 nanoglass with a grain size of 5 nm for balloon expandable stents by performing finite element method modeling of the stent deployment process in a coronary artery. We consider the BX-Velocity stent design and the nanoglass mechanical properties calculated from atomistic simulations. The results suggest that nanoglasses are suitable materials for balloon expandable stent applications. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:73-79, 2020.

03:36 PM Abstract No. 97 The Wallflex colonic stent adapted for endovascular treatment of malignant IVC obstruction

Malignant inferior vena cava (IVC) obstruction may cause debilitating ascites and lower extremity and perineal edema in late stage cancer patients. IVC stent placement can palliate symptoms, but available stents exhibit risk of migration and suboptimal radial strength and sizes. We report our early experience with use of the Wallflex colonic stent adapted for treatment of malignant IVC syndrome. From 2009-2018, self-expanding Wallflex colonic stents (all 25 mm diameter with a 30 mm distal flare; 60, 90, or 120 mm length) were placed in 36 patients (median age 63 yrs) to treat malignant IVC syndrome. Anatomical, procedural, and clinical outcome data were retrospectively evaluated. IVC obstruction was due to primary liver cancer (n = 9) or liver and/or retroperitoneal metastases (n = 27) with mean lesion length of 13.6 cm and baseline pressure gradient of 16.4±5.5 mm Hg (range 6-28). Ten patients had IVC tumor thrombus. Wallflex stents were placed transfemorally in 35 and by jugular vein in 1. The first 3 stents were placed for salvage fixation of Wallstents that had partially migrated into the right atrium. An additional 3 were used to treat recurrent or residual stenosis after Gianturco Z-stent placement. The Wallflex stent was the primary device in the remaining 30. Twelve cases required coaxial placement of Palmaz XL stents for additional radial strength. Technical success was 100% with pressure gradient reduction to 3.7±3.0 mm Hg (range 0-12, p<0.001). Post-stenting anticoagulation was given for 14 patients. In short-term follow-up, leg edema and/or ascites improved in 34 (94.4%) patients, unchanged in 2, unknown in 1. Acute IVC thrombosis occurred in 1 patient with extensive intraluminal tumor thrombus. Cranial stent migration was not seen intraprocedurally. In the one patient with transjugular stent placement, asymptomatic partial migration of the Wallflex stent into the right atrium was incidentally found on CT 38 days later. The Wallflex colonic stent is an attractive option adaptable for use in the palliative treatment of malignant IVC syndrome. Transfemoral stent placement is recommended. Reinforcement with balloon expandable stents may be necessary.

AN ALTERNATIVE WAY TO TREAT ILIAC ANEURYSM

Isolated iliac aneurysms or combined with aortic aneurysms can be treated through implantation of three balloon expandable polytetrafluoroethylene-covered stents in order to create a new iliac bifurcation. We present nine patients, unfit for open surgery and anatomically non suitable for

03:18 PM Abstract No. 270 Parallel TIPS versus DIPS for second percutaneous portosystemic shunt placement in cirrhotic patients with an existing TIPS

A second portosystemic shunt (sPSS) may be needed in patients with recurrent variceal bleeding or persistent ascites despite an existing transjugular intrahepatic portosystemic shunt (TIPS) due to insufficient portal decompression or shunt occlusion refractory to recanalization. There is no consensus on the best method for sPSS creation. The goal of this study was to compare the technical and clinical outcomes of placing a parallel TIPS (pTIPS) versus direct intrahepatic portocaval shunt (DIPS) as the sPSS. From 2002-2017, a pTIPS (n = 12; median age 62 y, MELD 13) or DIPS (n = 8; 57 y, 12) was placed in 20 patients with an existing TIPS and recurrent symptoms. sPSS indication, procedure details, technical and clinical success rates, and complications were retrospectively reviewed and compared. A sPSS was indicated for persistent ascites or recurrent variceal bleeding in 6 and 6 patients, respectively, in the pTIPS group and 6 and 2 patients in the DIPS group. The existing TIPS was patent in 5/12 patients in the pTIPS group and 4/8 in the DIPS group; the rest were chronically occluded. DIPS was specifically chosen in 5 cases due to anatomical limitations posed by the existing TIPS. In one pTIPS procedure, the existing occluded TIPS prevented full expansion of the new pTIPS, requiring balloon expandable stent placement. Stent-grafts were used in all cases (pTIPS: diameter 10 mm n=8, 8 mm n=4; DIPS: 10 mm n=5, 8 mm n=3, 7 mm n=1). Technical success was 100% in both groups. Mean procedure time for DIPS trended towards shorter versus pTIPS (73±22 vs 97±63 min, p=0.35) with a wider range in pTIPS procedure times (50-101 vs 72-262 min). Mean portosystemic gradient reductions after pTIPS (14.8±4.3 to 6.6±2.6 mm Hg) and DIPS (12.4±3.8 to 5.6±2.9) were similar. Ascites improved and variceal bleeding resolved in all patients. Hepatic encephalopathy worsened in 2 pTIPS and 1 DIPS patients. No acute liver failure occurred. Two pTIPS patients died within 30 days due to sepsis and lung cancer. Technical and clinical outcomes were similar between pTIPS and DIPS for sPSS creation. DIPS may be technically preferable due to anatomical issues in some patients with an existing TIPS.

Outcomes of Directional Branches Using Self-Expandable Versus Balloon-Expandable Stent Grafts During Endovascular Repair of Thoracoabdominal Aortic Aneurysms

The objective of this study was to evaluate outcomes of directional branches using self-expandable stent grafts (SESGs) or balloon-expandable stent grafts (BESGs) during fenestrated-branched endovascular aneurysm repair of thoracoabdominal aortic aneurysms. Patients treated with fenestrated-branched endovascular aneurysm repair in a prospective study using directional branches were included in the study. Choice of bridging stent evolved from SESG to BESG (Gore VBX; W. L. Gore & Associates, Flagstaff, Ariz) in February 2017. Target artery instability (TAI) was defined by stent occlusion, stenosis, separation, type IC or type IIIC endoleak, reintervention, rupture, or death due to target artery complication. End points included technical success; target artery patency; and freedom from TAI, type IC or type IIIC endoleak, and reintervention. There were 118 patients (60% male; mean age, 75 ± 7 years) with 296 renal-mesenteric arteries targeted by directional branches using SESGs in 69 patients/162 arteries or BESGs in 49 patients/134 arteries. Patients in both groups had similar aneurysm diameter, target artery diameter, and thoracoabdominal aortic aneurysm extent, which was I to III in 90%. Patients treated by SESGs had significantly (P < .05) shorter stent length (−7 mm), larger stent diameter (+1 mm), and more adjunctive bare-metal stents (74% vs 10%). Technical success was achieved in all patients, with no 30-day mortality. Mean follow-up was significantly longer among patients treated by SESGs (19 ± 12 months vs 6 ± 5 months). TAI occurred in 19 directional branches (6%), including 2 stent occlusions (all SESGs), 5 stenoses (3 SESGs, 2 BESGs), 2 separations (all SESGs), 9 type IC endoleaks (2 SESGs, 7 BESGs), and 4 type IIIC endoleaks (3 SESGs, 1 BESG), resulting in 15 reinterventions. At 1 year, there was no difference in primary (97% ± 1% vs 98% ± 1%; P = .77) and secondary patency (99% ± 1% vs 100%; P = .38) for SESGs and BESGs, respectively. However, SESGs had higher freedom from TAI (96% ± 2% vs 90% ± 4%; P = .005), type IC and type IIIC endoleaks (98% ± 1% vs 91% ± 3%; P = .003), and reinterventions (96% ± 1% vs 92% ± 4%; P = .02) compared with BESGs (Table). Factors associated with TAI were renal artery target (odds ratio, 2.8; P = .03) and lack of adjunctive bare-metal stents (odds ratio, 0.2; P = .004). Directional branches were associated with high technical success and low rates of occlusion or stenosis, independent of stent type. However, freedom from TAI was lower for BESGs because of more target artery endoleaks.TableThe 1-year Kaplan-Meier estimates ratesBESG (n = 49 patients/134 arteries)SESG (n = 69 patients/162 arteries)P valueAll target arteries (n = 296) Primary patency98 ± 197 ± 1.77 Secondary patency10099 ± 1.38 Freedom from TAI90 ± 496 ± 2.005 Freedom from target artery reintervention92 ± 496 ± 1.02Renal artery targets (n = 108) Primary patency96 ± 492 ± 3.76 Secondary patency10096 ± 3.37 Freedom from TAI80 ± 892 ± 4.003 Freedom from target artery reintervention83 ± 894 ± 3.01Celiac and superior mesenteric artery targets (n = 188) Primary patency99 ± 1100.26 Secondary patency100100NA Freedom from TAI96 ± 298 ± 1.38 Freedom from target artery reintervention97 ± 298 ± 1.69BESG, balloon-expandable stent graft; NA, not applicable; SESG, self-expandable stent graft; TAI, target artery instability.Values are presented as percentage ± standard error. Boldface entries indicate statistical significance. Open table in a new tab

Endovascular Revascularization of a Chronic Occluded Aortobifemoral Bypass

Bilateral limb occlusion after aortobifemoral (ABF) prosthesis occurs in 1-3% patients. Multiple remedial choices are known in literature to manage a bilateral occluded ABF such as "redo" ABF bypass, axillobifemoral bypass, endovascular recanalization of the native aortoiliac system, and thrombectomy. We present a patient with an occluded ABF bypass since 2001. A new minimal invasive treatment strategy was performed by traversing the occluded limbs with aortic re-entry using stiff Terumo wires. To make way for safe passing of the stents, kissing balloon angioplasty was performed of the entire ABF bypass. Kissing Viabahn (W. L. Gore & Associates, Flagstaff, AZ) balloon-expandable stents were placed in the proximal part of the ABF bypass and extended with a Viabahn self-expandable stent (standard Viabahn). This option should be added to the known multiple remedial choices in case of bilateral limb occlusion of an ABF.

Abstract WMP35: A Novel Microporous Covered Stent NCVC-CS1 for the Treatment of Intracranial Aneurysms: Its Functional Features and Preliminary Results of Clinical Trial

Background and Purpose: The treatment for large and giant intracranial aneurysms remains unsatisfactory even after the introduction of flow diverters, especially in those located in posterior circulation. This study was aimed to assess the novel covered stent graft named NCVC-CS1 for the treatment of such complex aneurysms. Materials and Methods: NCVC-CS1 is a balloon-expandable stent covered with a thin, microporous segmented polyurethane membrane. After the confirmation of its function on navigability, aneurysm occlusion, and patency of branching vessels using animal models, an investor-initiated, first-in human clinical trial to evaluate the safety and efficacy of NCVC-CS1 was conducted. The inclusion criteria for the targeted aneurysm were unruptured, wide-necked aneurysms more than 7 mm, located in petrous/cavernous portion of ICA, intradural VA, or BA proximal to the orifice of superior cerebellar artery. The primary effectiveness endpoint was angiographic evaluation that demonstrated complete aneurysm occlusion and patency of target vessel (less than 50% stenosis) at 180 days. The primary safety endpoint was occurrence of any stroke or death related to the procedure. Results: A total of 10 patients were enrolled in the trial. Among them, nine aneurysms were large (more than 10mm) including one giant aneurysm (more than 25mm). Mean aneurysm size was 14.3mm. Five aneurysms (50%) were located in VA. NCVC-CS1 placement was technically successful in all cases. No coils were used. The instant cessation of inflow to the targeted aneurysm at the time of the procedure (so-called eclipse sign) was observed in nine cases (90%). Among the nine cases whose follow-up data at 180 days were obtained, five (55%) met the study’s primary effectiveness endpoint whereas the other four showed near complete occlusion without stenosis of the parent artery. As to the safety endpoint, one patient experienced a non-disabling infarction. No subsequent rupture of the aneurysm was observed during the follow-up period. Conclusion: NCVC-CS1 showed the safety and efficacy on its first-in-human clinical trial. This device can offer another therapeutic choice for wide-necked and large intracranial aneurysms.

Successful treatment of a benign biliary stricture with biodegradable metallic biliary stents

Background: A 19 year old boy from a UNHCR camp presented to our hospital with an insidious onset of painless jaundice without any constitutional symptoms. Biochemical and ultrasonograph confirmed obstructive jaundice. Tumor markers, brush cytology and infective parameters were all negative. We successfully treated the symptoms with a biodegradable metallic biliary stent. Methods: Pre-procedural MRCP confirmed presence of benign stricture at distal CBD with dilated biliary systems. We obtained consent to deploy a 10mm diameter x 40mm length Biodegradable Balloon Expandable Biliary Stent System (QualiMed Innovative Medizinprodukte GmbH, Germany) across the stricture via ERCP. It is a flexible, magnesium based stent pre-mounted on the balloon of an over-the-wire (OTW) stent delivery system. Results: Patient's symptom resolved. We performed a repeat MRCP and ERCP at 10 months. The stent has been fully degraded. There was no residual stricture and patient remained clinically and biochemically not jaundiced. The radial strength of the biodegradable biliary stent support and maintained the patency across the distal biliary stricture. It provided a controlled delayed degradation over time. The stent has a good fluoroscopic visibility with minimal foreshortening. Conclusion: The usability and mechanical properties of the Biodegradable Balloon Expandable Biliary Stent System are comparable to regular metalic stent systems, but with the advantage of fully degraded and leaving nothing behind.

Which Pulmonary Homograft to Use in Patients With Major Aortopulmonary Collateral Arteries and Pulmonary Hypertension?

The patient was a 19-year-old male who had complex congenital heart disease with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries (MAPCAS). He underwent serial unifocalisation of unilateral MAPCAS to pulmonary homograft tubes with arterial pulmonary shunt supply. Anatomical correction was achieved by removal of arterial shunts, application of a Dacron tube graft to the homograft tubes, which was connected to a 20-mm Hancock bioprosthesis pulmonary valve associated with ventricular septal defect closure at age 7 years. Later in life, he developed right pulmonary artery stenosis and pulmonary valve stenosis. Right pulmonary artery stenosis was treated with a tissue patch and balloon expandable stent. Pulmonary valve stenosis was treated with balloon dilatation. A subsequent attempt at right ventricular outflow tract (RVOT) reconstruction with a pulmonary homograft failed, due to suture line rupture secondary to high RV pressures (90/12 mmHg). This required emergent surgery for a RV-pulmonary artery conduit change with a 22-mm Contegra conduit. Major aortopulmonary collateral arteries is one of the most challenging conditions to manage. Reconstruction of the RVOT may require pulmonary valve replacement with a cryopreserved homograft or bovine jugular vein graft (Contegra) during primary repair or re-operation. One study showed that although survival and freedom from distal stenosis were similar between the two conduits, freedom from failure, dysfunction, and explantation were better with Contegra conduits in patients needing RVOT reconstruction. Furthermore, choice of RV-pulmonary artery conduit must take into account the pulmonary artery pressure, with a pulmonary homograft contraindicated with PAP >50 mmHg.

Self-Expandable Stents in Vascular Stenosis of Moderate to Large-Sized Vessels in Congenital Heart Disease: Early and Intermediate-Term Results

Background and ObjectivesVascular stenosis after surgical repair frequently occurs in congenital heart disease. Although conventional balloon dilation is a useful option for stenotic lesions, restenosis may occur. Consequently, balloon expandable stents have been used; however, there are a limited number of balloon expandable stents in our country. Here, we report the early and intermediate-term outcomes of self-expandable stents in vascular stenosis of moderate to large-sized vessels in congenital heart disease.MethodsTwelve self-expandable stents were implanted in 9 patients between February 2012 and January 2019. The median age and weight were 12 years (range, 4–39 years) and 38 kg (range, 19–69 kg), respectively. The patients were followed-up for a median duration of 43 months (range, 1–83 months) after stent implantation.ResultsNine self-expandable stents were implanted in the pulmonary artery, 2 stents in the right ventricle to the pulmonary artery conduit, and 1 stent in the coarctation. The narrowest diameter of the stented vessel increased from 5.7±3.2 mm to 12.6±3.4 mm (p<0.05). The mean pressure gradient across the stenotic lesion decreased from 23.0±28.2 mmHg to 3.2±3.6 mmHg (p<0.05). Distal migration of the stent occurred in 1 patient, and significant neointimal ingrowth was noted in 1 patient.ConclusionsThe self-expandable stent may be a useful option to relieve vascular stenosis in moderate to large-sized vessels with acceptable intermediate-term outcomes.

Influence of design on tensile deformation behavior of balloon expandable stent

Influence of design on tensile deformation behavior of balloon expandable stent

First-in-man pulmonary artery stenting in children using the Bentley® BeGrow™ stent system for newborns and infants

BackgroundStent implantation into growing vessels is a common treatment option in infants and children with congenital heart disease (CHD) and corresponding vessel lesions. After stent implantation in small children, repetitive stent redilations are frequently necessary to accommodate for somatic growth. Until now, all available stents have limited final expansion diameters. Material and resultsThe new Bentley BeGrow™ stent system for newborns and infants is a L605 cobalt‑chromium, pre-mounted, balloon expandable stent, which is compatible with a 4 French sheath and 0.014 inch guide wire thus allowing implantation in small vessels (4–6 mm). It offers a new, unique stent design that allows post-dilation steps up to Ø11.5 mm. While re-dilating up to Ø11.5 mm this new stent maintains radial force and shows uniform expansion with only minimal foreshortening. Predetermined breaking points allow the stent struts to break in a controlled manner when exceeding a diameter of 11.5 mm. Residual radial force maintains even after stent opening due to spiral arrangement of the predetermined breaking points. The 2 first-in-man pulmonary artery stent implantations in a newborn with univentricular circulation and a toddler with biventricular circulation are reported as part of the currently performed licencing trial (ClinicalTrials.govNCT03287024). ConclusionThe low-profile BeGrow™ stent system offers new treatment options for transcatheter stent implantations in newborns and infants. In our first experience, it can be effectively implanted. Longer follow-up will evaluate multiple, stepwise redilations and controlled stent strut breakage, which have the potential to accommodate for somatic vessel growth and/or subsequent implantation of larger stents.

Multicenter experience with endovascular treatment of aortic coarctation in adults

ObjectiveThe objective of this study was to evaluate outcomes of endovascular treatment of aortic coarctation in adults. MethodsClinical data and imaging studies of 93 consecutive patients treated at nine institutions from 1999 to 2015 were reviewed. We included newly diagnosed aortic coarctation (NCO), recurrent coarctation, and aneurysmal/pseudoaneurysmal degeneration (ANE) after prior open surgical repair (OSR) of coarctation. Primary end points were morbidity and mortality. Secondary end points were stent patency and freedom from reintervention. ResultsThere were 54 (58%) male and 39 (42%) female patients with a mean age of 44 ± 17 years. Thirty-two patients had NCO (mean age, 48 ± 16 years) and 61 had endovascular reinterventions after prior OSR during childhood (mean, 30 ± 17 years after initial repair), including 50 patients (54%) with recurrent coarctation and 11 (12%) with ANE. Clinical presentation included asymptomatic in 31 patients (33%), difficult to control hypertension in 42 (45%), and lower extremity claudication in 20 (22%). Endovascular treatment was performed using balloon-expandable covered stents in 47 (51%) patients, stent grafts in 36 (39%) patients, balloon-expandable uncovered stents in 9 (10%) patients, and primary angioplasty in 1 (1%) patient. Mean lesion length and diameter were 64.5 ± 50.6 mm and 19.5 ± 6.7 mm, respectively. Mean systolic pressure gradient decreased from 24.0 ± 17.5 mm Hg to 4.4 ± 7.4 mm Hg after treatment (P < .001). Complications occurred in nine (10%) patients, including aortic dissections in three (3%) patients and intraoperative ruptures in two patients; type IA endoleak, renal embolus, spinal headache, and access site hemorrhage occurred in one patient each. The aortic dissections and ruptures were treated successfully by deploying an additional covered stent proximal to the site of dissection or rupture. Two patients died within 30 days of the index procedure. After a mean follow-up of 3.2 ± 3.1 years, nearly all patients (98%) were clinically improved and all stents were patent. Reintervention was needed in 10 (11%) patients. Freedom from reintervention at 5 years was 85%. Two additional patients died during follow-up of coarctation-related causes, including rupture of an infected graft and visceral ischemia. Patient survival at 5 years was 89%. ConclusionsEndovascular repair is effective with an acceptable safety profile in the treatment of NCO and postsurgical complications of coarctation after initial OSR. Aortic rupture is an infrequent (2%) but devastating complication with high mortality. Balloon-expandable covered stents are preferred for NCO, whereas stent grafts are used for ANE. The rate of reinterventions is acceptable, with high procedural and long-term clinical success.