Prestent Angioplasty Research Articles

Right Ventricular Outflow Tract Stenting is a Safe and Effective Bridge to Definitive Repair in Symptomatic Infants With Tetralogy of Fallot1.

Right ventricular outflow tract (RVOT) stent angioplasty is a palliative procedure for neonates and infants with symptomatic tetralogy of Fallot prior to surgical repair. We review our institutional outcomes of RVOT stenting. Retrospective review of all infants with tetralogy of Fallot under 3 months of age who underwent primary native RVOT stent angioplasty at The Children's Hospital at Westmead, Sydney, Australia between January 2010 and December 2020. Demographics and echocardiographic pulmonary artery dimensions were collected pre-stent angioplasty and prior to surgical repair. Twenty (20) infants underwent primary RVOT stenting. Median age at stent was 14 days (interquartile range [IQR] 7-32) and median weight 2.7 kg (IQR 2.1-3.4). Three patients underwent hybrid per-ventricular procedures. Indication for RVOT stenting was recurrent hyper-cyanotic spells in 12 (60%) and duct-dependent pulmonary blood flow in 8 (40%). Saturations increased from a median of 80% (IQR 75-85) to 91% (IQR 90-95) post procedure (P<0.001). A single major complication occurred: transient complete atrioventricular dissociation requiring isoprenaline infusion for <24 hours. Twelve (12, 60%) required catheter re-intervention prior to definitive repair for further augmentation of pulmonary blood flow. There were two non-cardiac deaths distant from the stent procedure, but prior to surgical repair. Median right and left pulmonary artery Z-scores increased respectively from -2.06 (IQR -2.99 to -0.17) and -1.2 (IQR -2.59 to -0.14) prior to RVOT stent, to -0.74 (IQR [-1.21 to 0.26], P=0.01) and 0.06 (IQR [-1.87 to 1.15], P=0.006) by the time of definitive repair. Eighteen (18) patients achieved definitive repair at a median age of 6.1 months (IQR 4.7-7.3). Palliation with more than one RVOT stent was associated with an increased duration of cardiac bypass (P=0.035) and cross-clamp (P=0.044) time at definitive repair. In symptomatic neonates and infants with tetralogy of Fallot at high-risk of peri-operative complications, RVOT stent angioplasty can safely and effectively augment pulmonary blood flow prior to definitive repair.

Intracranial Angioplasty and Stent Placement After Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis (SAMMPRIS) Trial: Present State and Future Considerations⋆

The results of prematurely terminated stenting and aggressive medical management for preventing recurrent stroke in intracranial stenosis (SAMMPRIS) due to excessively high rate of stroke and death in patients randomized to intracranial stent placement is expected to affect the practice of endovascular therapy for intracranial atherosclerotic disease. The purpose of this report is to review the components of the designs and methods SAMMPRIS trial and to describe the influence of those components on the interpretation of trial results. A critical review of the patient population included in SAMMPRIS is conducted with emphasis on "generalizability of results" and "bias due to cherry picking phenomenon." The technical aspects of endovascular treatment protocol consisting of intracranial angioplasty and stent placement using the Gateway balloon and Wingspan self-expanding nitinol stent and credentialing criteria of trial interventionalists are reviewed. The influence of each component is estimated based on previous literature including multicenter clinical trials reporting on intracranial angioplasty and stent placement. The inclusion criteria used in the trial ensured that patients with adverse clinical or angiographic characteristics were excluded. Self-expanding stent as the sole stent, technique of prestent angioplasty, periprocedural antiplatelet treatment, and intraprocedural anticoagulation are unlikely to adversely influence the results of intracranial stent placement. A more permissive policy toward primary angioplasty as an acceptable treatment option may have reduced the overall periprocedural complication rates by providing a safer option in technically challenging lesions. The expected impact of a more rigorous credentialing process on periprocedural stroke and/or death rate following intracranial stent placement in SAMMPRIS such as the one used in carotid revascularization endarterectomy versus stenting trial remains unknown. The need for developing new and effective treatments for patients with symptomatic intracranial stenosis cannot be undermined. The data support modification but not discontinuation of our approach to intracranial angioplasty and/or stent placement for intracranial stenosis. There are potential patients in whom angioplasty and/or stent placement might be the best approach, and a new trial with appropriate modifications in patient selection and design may be warranted.

A Technical Strategy for Carotid Artery Stenting: Suboptimal Prestent Balloon Angioplasty Without Poststenting Balloon Dilatation

Traditional carotid artery stenting (CAS) consists of predilatation, optional deployment of embolic protection devices, stenting, and poststent angioplasty. Each step carries a risk of thromboembolism. To design a new and simplified procedural protocol, suboptimal balloon angioplasty without routine poststenting balloon dilatation, and to describe the efficacy this protocol in terms of procedural risks and angiographic and clinical outcomes. Over a period of 6 years, 161 carotid artery stenoses in 156 consecutive patients were treated by CAS with embolic protection devices. Among them, 110 lesions in 107 patients (68.3%) were treated by our simplified method (symptomatic, > 50% stenosis; asymptomatic, > 70% stenosis). Overall, 98 lesions (88.3%) had severe stenosis (> 70%). The mean stenosis was reduced from 77% to 10% after CAS. A persistent neurological deficit developed in 2 patients from thromboembolism. Hemodynamic insufficiency developed in 14 lesions during CAS (12.7%). The ipsilateral stroke and mortality rate was 4.5% within 1 month after CAS (asymptomatic, 3.6%; symptomatic, 4.8%). Over a mean of 19 months of follow-up, additive angioplasty was performed in 2 patients as a result of progressive restenosis (≥ 50%). A comparison of the balloon sizes of the prestent angioplasty for group 1 (balloon, ≤ 4 mm) and group 2 (balloon, ≥ 5 mm) showed no difference in restenosis between the groups at 15 months of follow-up after CAS. Our CAS technique with suboptimal prestenting angioplasty without routine use of poststenting dilatation is safe, simple, and efficient with acceptable risks.

Intermediate follow‐up following intravascular stenting for treatment of coarctation of the aorta

We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques. Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up. Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

RECANALIZATION OF A SYMPTOMATIC EXTRACRANIAL INTERNAL CAROTID ARTERY NEAR OCCLUSION WITH PROXIMAL AND DISTAL PROTECTION

To describe a novel approach to recanalizing symptomatic extracranial internal carotid artery near occlusion using proximal and distal emboli protection devices. Patients presenting with symptomatic extracranial internal carotid artery near occlusion who underwent endovascular recanalization between October 2004 and July 2005 were included in this study. During these procedures, a 9-French Concentric Balloon Guide Catheter (Concentric Medical, Mountain View, CA) was advanced into the common carotid artery proximal to the site of occlusion. During the prestent angioplasty of the lesion, the proximal balloon was inflated and aspiration was performed. After initial angioplasty and before stent placement, a distal filter protection device was placed in the distal internal carotid artery. Stent placement and repeat angioplasty were performed with both protection devices active. All patients were placed on dual antiplatelet therapy. There were four patients treated with a mean age of 74 years; three of these four patients were men. All patients had signs of ischemia and carotid occlusion or near occlusion on noninvasive imaging. Three right internal carotid arteries were treated. All patients were successfully recanalized. No procedurally related complications or deaths occurred. This series demonstrates the feasibility of recanalization of symptomatic carotid artery occlusion or near occlusion using proximal and distal emboli protection devices. Such an approach may provide an added level of safety during carotid recanalization procedures.

Intravascular ultrasound identification of intraluminal embolic plaque material during carotid angioplasty with stenting

Carotid angioplasty with stenting (CAS) has evolved as a viable method for treating patients at high risk for carotid endarterectomy. Strokes complicating CAS are most commonly caused by the liberation and distal embolization of embolic material from plaque during the procedure. CAS with distal embolic protection (DEP) was performed using the assistance of intravascular ultrasound (IVUS) in a 68-year-old man with asymptomatic carotid artery stenosis. Evaluation of the plaque pretreatment was performed using virtual histology software. IVUS evaluation was also performed after prestent angioplasty, stenting, and poststent angioplasty. Initial degree of angiographic stenosis was 78.9%. Final degree of stenosis was 15.7%. By IVUS, stenosis by minimum lumen diameter and minimum lumen area were 75.6% and 93.4% pretreatment, respectively, and 42.2% and 47.1% posttreatment, respectively. An intraluminal lesion was noted in the distal aspect of the stent after poststent angioplasty but before DEP device removal. Ultrasonographic characteristics of the intraluminal defect were consistent with ruptured plaque material. Angiographic runs failed to demonstrate the lesion. A repeat IVUS run performed approximately 10 min later failed to depict the lesion, suggesting that distal embolization had occurred. Embolic material was noticed in the DEP device after removal. The patient did not experience any ischemic neurological symptoms. IVUS can identify intraluminal plaque material, which may be a precursor for embolism and delayed ischemic events after CAS. IVUS may allow for treatment before distal embolization of plaque material. Virtual histology IVUS software may help to identify carotid lesions at higher risk for significant embolization during CAS.

Stent placement for vertebral artery occlusive disease: preliminary clinical experience

Symptoms of vertebrobasilar insufficiency may precede neurological sequelae in up to 50% of patients. Although select patients may benefit from microsurgical revascularization, combined perioperative morbidity and mortality rates can be as high as 20%. The authors present their preliminary clinical experience using stent placement for symptomatic vertebral artery (VA) occlusive disease. Six patients with clinical symptoms of vertebrobasilar insufficiency in whom VA stents were placed from 1995 to 1998 were identified. Diagnostic four-vessel cerebral angiography identified causative stenotic, atherosclerotic lesions in all cases. A transfemoral or transradial artery approach after the patient had undergone full heparinization was chosen for endovascular stenting. Guidewire placement across the lesion followed by urokinase infusion preceded stenting. Prestent angioplasty was performed in two patients. Following the procedure, all patients were maintained on daily antiplatelet therapy. Patient age ranged from 45 to 76 years (average 63 years). Four patients were men and two were women. Angiography revealed greater than 95% stenosis in five patients and greater than 70% stenosis in one. Three patients had complete occlusion of the contralateral VA; in one other, the VA supplied only the posterior inferior cerebellar artery; and the remaining two patients had VAs with greater than 70% stenosis. Ten stents were placed in six patients for five VA origin lesions and one distal VA stenosis. A VA dissection occurring poststenting was treated by placement of three additional stents. One patient had transient double vision. All had resolution of their presenting symptoms. Follow up ranged from 1 to 24 months (average 8.4 months). Angiograms obtained in four patients at least 3 months postprocedure have revealed stent patency in all cases without evidence of restenosis. Vertebral artery stent placement can be safely performed and is a viable treatment option for carefully selected patients with vertebrobasilar insufficiency.