Influence of balloon design, plaque material composition, and balloon sizing on acute post angioplasty outcomes: An implicit finite element analysis.

The purpose of this work is to present a patient-specific (PS) modeling approach for simulating percutaneous transluminal angioplasty (PTA) endovascular treatment and assessing the balloon sizing influence on short-term outcomes in peripheral arteries, i.e. without stent implantation. Two 3D PS stenosed femoral artery models, one with a dominant calcified atherosclerosis while the other with a lipidic plaque, were generated from pre-operative computed tomography angiography images. Elastoplastic constitutive laws were implemented within the plaque and artery models. Implicit finite element method (FEM) was used to simulate the balloon inflation and deflation for different sizings. Besides vessel strains, results were mainly evaluated in terms of the elastic recoil ratio (ERR) and lumen gain ratio (LGR) attained immediately after PTA. Higher LGR values were shown within the stenosed region of the lipidic patient. Simulated results also showed a direct and quantified correlation between balloon sizing and LGR and ERR for both patients after PTA, with a more significant influence on the lumen gain. The max principal strain values in the outer arterial wall increased at higher balloon sizes during inflation as well, with higher rates of increase when the plaque was calcified. Results show that our model could serve in finding a compromise for each stenosis type: maximizing the achieved lumen gain after PTA, but at the same time without damaging the arterial tissue. The proposed methodology can serve as a step toward a clinical decision support system to improve angioplasty balloon sizing selection prior to the surgery.

A novel approach to the balloon angioplasty of a native discrete severe coarctation of the aorta in the management of hypertension.

Diabetes modifies the relationships among carotid plaque calcification, composition and inflammation.

The introduction of coronary artery stents into widespread clinical use in the mid-1990s was a significant advance that almost rivals the introduction of balloon angioplasty itself 15 years earlier. It is noteworthy that the success of stents required several paradigm shifts. For example, higher-pressure balloon inflations and slight oversizing were needed to achieve full stent expansion (anathema in balloon angioplasty), and antiplatelet therapies were required rather than anticoagulation, including a reduction and now almost elimination of heparin. Yet, these changes were quickly accomplished. Technical advances in equipment also occurred, and now stenting, quite literally, has become the standard in clinical practice when it can be performed (which is most of the time). One curious and intriguing question that arises with any new device, and stents are no exception, is whether they are needed in all situations where they are being used. Is it possible that balloon angioplasty alone might be sufficient for excellent immediate and long-term benefit, provided the final procedural result is good enough? If one could determine this to be true, then such a strategy would avoid the additional cost of a stent and the problem (or pseudo-problem) of in-stent restenosis. However, a provisional stent strategy raises the further and not inconsiderable question of how to decide when balloon angioplasty results are “good enough.” The limitations of standard angiography notwithstanding, is there anything better than the eyes and minds of experienced angiographers? Additional “objective” measures to assess procedural results have long been sought. A number of investigators have championed intracoronary ultrasound as one approach, whereas others suggest alternative methods. In this issue of Circulation , 2 separate groups report their findings using combined anatomic and functional coronary measures to assess balloon angioplasty results for the purpose of provisional stenting.1 2 These measures are on-line quantitative coronary arteriography …

IAB size selection is based on patients height with the known risks of under or over sizing, although size selection should rely on individual hemodynamics & measurements of the length & diameter of the aorta from the left subclavian artery to the celiac axis. The first part of this project is a pilot study whereby an attempt was made, in order to predict thoracic aortic dimensions from easily obtainable external anatomical landmarks. That would potentially lead to an optimal selection of balloon sizes for an individual patient and thus reducing adverse effects of its use. The second part of the project is an experimental Angioscopic and Pathological study that set off to investigate in a mock pig circulation model, whether weaning by mode or by augmentation produces more aortic intimal trauma. The third part of this work, studied the interaction between the intraaortic balloon catheter and the human atherosclerotic aorta. With the use of an artificial circulation we obtained direct visualisation of the dynamic action of the balloon catheter within the cadaveric human aorta. Sequelae of traumatic atherosclerotic plaque rapture due to the balloon action was observed. The last study was a clinical outcome analysis with an interest in complications in a cohort of patients requiring treatment with IABP in a single Cardiothoracic Unit over a five year period. During the initial part of the project, measurements were carried out from a series of 40 cadavers during autopsy. Internal Aortic dimensions and also external somatometric distances of the thoracic cage were obtained. Using multiple regression analysis a model was devised in order to predict aortic lengths. Being able to calculate internal aortic lengths, one could be lead to a better intraaortic balloon sizing. During the second part of the study an artificial pulsatile pump was used and an intact porcine aorta was incorporated into the circuit with the inflow at the aortic valve and the outflow at the right common iliac artery. Direct angioscopic images of the interior of the aorta were obtained. Keeping steady hemodynamic conditions, an “aortic impact score” was calculated taking into account angioscopic observational variables and biopsies of the aorta at 30min, 6hours and 12 hours following counterpulsation at 1:1, 1:2 ,1:3 Versus 1:1 and 75%, 50% and 25% augmentation. The previous model was extrapolated in to the third study whereby an artificial circulation was constructed using of PVC tubing, a filter and a roller pump. A series of 5 intact cadaveric human aortas were then individually studied by placing each in series within the circuit. A balloon catheter was advanced via the left common iliac artery into the descending aorta under direct angioscopic vision. Balloon pumping was then commenced. The circuit was perfused with Normal saline at a flow rate of 3L/minute. Pump actions of 1:1 and 1:2 were simulated. A microporous filter was incorporated into the system in order to collect embolic material during balloon action. Each aorta at the end of the experiment was subjected to histological examination. During the last study data were prospectively collected within a 5 year period from a single Cardiothoracic Unit. 2697 adult patients underwent cardiac surgery, out of which 136patients (5%) required IABP. Those patients were studied in terms of balloon associated complications. We create a model of optimal balloon sizing with a high prediction value. The performance of the model was tested against the current quidelines in a cross validation way and was found to be superior. Together with height, somatometric measurements of thoracic cage could lead to more optimal IAB size selection. During the angioscopic observational studies with porcine and also cadaveric aortas the movement of the balloon catheter in relation to the aorta was observed. The balloon catheter moves relative to the wall of the aorta during inflation and deflation. Contact between the balloon and the aorta only occurs during deflation. Side branches of the aorta are not occluded by the catheter. Plaque disruption and embolus formation appear to result from pressure wave action rather than direct contact with the balloon. By calculating the aortic impact score it appears that weaning by mode produces more aortic intimal trauma. 1:3 mode produces marked intimal disruption that worsens with time. Lastly during the clinical study of patients requiring treatment with an IABP we detected significant early mortality and morbidity associated with IABP, however intermediate follow up reveals favourable outcome.

Ultrasound-guided percutaneous endovascular treatment of arteriovenous fistula (AVF) or graft failure is an alternative to radiologically-guided angioplastic methods. Its main advantages are that it can be used with open or percutaneous access, using no contrast media and no radiation. The aim of this study was to analyze the results of ultrasound-guided endovascular treatment of arteriovenous access failure. Preoperative ultrasound was used to determine the degree of stenosis and the size of balloon used in angioplasty. Angioplasty was performed as open procedure or by using a 4-6 French percutaneous sheath. Indications for angioplasty were significant stenosis of native vein or polytetrafluoroethylene (PTFE) graft with or without AVF thrombosis. Stenosis was considered significant if it narrowed the lumen of AVF for more than 50% and changed the shape of the flow curve. Balloon inflation was controlled by ultrasound. Procedural success was assessed with repeated postprocedural ultrasound. In the period from August 2012 until August 2016, 228 ultrasound-guided open or percutaneous transluminal angioplasties (PTA) were performed (61% men, mean age 66.6±12.0 years), success rate was 93%. In 19 (8%) cases, ultrasound-guided PTA was used in conjunction with surgical reconstruction of arteriovenous fistula/graft and in 27 (12%) cases with thromboendarterectomy. Main complications were recoil, phlebitic vein rupture, and guidewire false route in thrombotic vessels. The main cause of access failure was perianastomotic stenosis (25%). 46% of patients required repeated PTA after the first one (after a mean time of 20.8±22.8 weeks, mean number of repeated PTA 2.1±1.7). Repeated PTA was done intentionally as stepped dilatation or because of rethrombosis/restenosis. Ultrasound-guided stent placement was done in 8% of PTA. Ultrasound-guided endovascular treatment of arteriovenous fistula or graft is a feasible and safe method of reestablishing or maintaining a functional vascular access. .

Target lesion calcification is known to influence the percutaneous coronary intervention (PCI) outcomes. This study aimed to assess the impact of calcium fractures after balloon angioplasty on the PCI results as well as the long-term clinical outcomes. We formed a prospective, multicenter registry that enrolled 268 patients who underwent PCI to lesions with moderate to severe calcification. Balloon dilatation and subsequent drug eluting stent implantation were performed with optical coherence tomography (OCT) guidance in every case. Serial OCT images just before and after balloon angioplasty, and after stent implantation were analyzed at 1-mm intervals by an independent core laboratory. The primary endpoint was the relationship between calcium fracture after balloon angioplasty and stent expansion. The secondary endpoint was target vessel failure (TVF) at 1 year, defined as a composite of cardiac death, target vessel-related myocardial infarction, and target vessel revascularization. A total of 242 patients were analyzed. Of these, OCT analysis was performed in 147 patients with a complete OCT data set. Calcium fractures were observed in 28 patients (19%) at the minimal lumen area site. The percent stent expansion was greater in lesions with calcium fracture than those without (99 ± 26% vs. 91 ± 18%, p = 0.039). In 229 patients who underwent clinical follow-up at 1 year, TVF occurred in 23 patients (10.0%). The OCT-guided PCI strategy demonstrated acceptable acute and 1-year clinical outcomes. The presence of calcium fractures after balloon angioplasty may have a potential impact on acute results after DES implantation in calcified lesions.

BackgroundIn patients with refractory intracranial atherosclerotic disease (ICAD), percutaneous transluminal balloon angioplasty (PTBA) is less complex but typically results in higher postprocedural residual stenosis than percutaneous transluminal angioplasty with stenting...

Background: Peripheral pulmonary artery stenosis is a relatively frequent anomaly responsible for right ventricular hypertension, significantly affecting the quality of life and the long‐term prognosis of patients with congenital heart disease. Balloon angioplasty has been used to relieve pulmonary artery stenosis, but immediate and long‐term results have not been completely satisfactory. Conversely, stent implantation seems a promising and more effective technique for the treatment of this vascular anomaly. Methods: Between April 1987 and September 1997, indication for interventional cardiac catheterization has been estabilished for 150 patients. Balloon angioplasty was performed in 120 patients (162 procedures) and stent implantation in 60 patients (79 stents). In 30 patients, both procedures have been carried out. Indication was based on the presence of right ventricular hypertension (right ventricular/systemic peak systolic pressure ratio ≥ 0.5), right ventricular dysfunction, or a markedly unbalanced pulmonary blood flow, especially after bidirectional cavopulmonary anastomosis. Criteria for technical success of balloon dilation were defined as a ≥ 50% increase in the predilation diameter, a ≥ 50% decrease in the transstenotic pressure gradient, or a ≥ 20% decrease in the right ventricular‐to‐aortic pressure ratio. Mean balloon/stenosis diameter ratio was 3.0 ± 0.7 (range 1.8–4.2). Time between primary surgery/balloon angioplasty and stent implantation was 18 ± 7 months (range 8–21 months). Stainless steel balloon‐expandable endovascular stents were maximally dilated to 12–18 mm of diameter, and high‐pressure dilations were performed to further expand the stent, if necessary. Results: After balloon angioplasty, the diameter of the stenotic segment increased from 3.1 ± 0.3 to 5.1 ± 1.4 mm (P < 0.01), the gradient across the stenotic segment dropped from 51 ± 19 to 28 ± 8 mmHg (P < 0.01), and the right ventricular/systemic peak pressure ratio decreased from 0.81 ± 0.20 to 0.65 ± 0.15 (P < 0.05). No significant difference between procedures with low‐pressure and high‐pressure dilation was recorded. Success rates using the above‐mentioned criteria could be assessed as high as 60%. After stent implantation, the diameter of the stenotic segments increased from 3.5 ± 1.2 to 13.2 ± 3.4 mm (P < 0.01), the pressure gradient across the stenotic segment dropped from 53 ± 30 to 13 ± 10 mmHg (P < 0.01), and the mean right ventricular/systemic pressure ratio decreased from 0.84 ± 0.2 to 0.40 ± 0.15 (P < 0.01). Immediate overall success for balloon angioplasty was achieved in 73 of 120 patients compared with 58 of 60 patients submitted to stent implantation (60% vs 97%, P < 0.001). The complication rate was 6.9% (5/162 procedures) in the balloon angioplasty group and 1.2% (1/79 implants) in the stent group. Restenosis has been recorded in 25% of the balloon group patients, in respect to 2% of the stent group. Conclusions: Peripheral pulmonary stenosis (PPS) is an important factor conditioning outcome of patients with congenital heart defects. Balloon angioplasty may be technically effective, but it often fails if clinical criteria and impact on patient's outcome are considered. In our experience, the use of high‐pressure balloons did not change the success rate of balloon dilation. Stent implantation seems to offer a better and more definitive approach for the relief of PPS.

A systematic review and meta-analysis of plain versus drug-eluting balloon angioplasty in the treatment of juxta-anastomotic hemodialysis arteriovenous fistula stenosis

Balloon angioplasty plus stenting or atherectomy plus drug-coated balloon angioplasty in endovascular repair of the common femoral artery.

A prospective randomized study of stent graft placement after balloon angioplasty versus balloon angioplasty alone for the treatment of hemodialysis patients with prosthetic graft outflow stenosis

To investigate whether endovascular brachytherapy diminishes vascular inflammation in response to femoropopliteal percutaneous transluminal angioplasty (PTA) or stent implantation in two double-blind randomized-controlled trials. Forty-seven consecutive patients from two double-blind randomized-controlled trials were studied. Patients either underwent femoropopliteal PTA with endovascular gamma irradiation (n = 8) or placebo irradiation (n = 7) or underwent PTA and stent implantation with brachytherapy (n = 15) or placebo irradiation (n = 17). High-sensitivity C-reactive protein (CRP), serum amyloid A (SAA), and fibrinogen levels were measured at baseline and 8, 24, and 48 hours after the intervention. The change of acute phase parameters from baseline to 48 hours after intervention indicated the extent of the inflammatory response and was compared between patients undergoing brachytherapy and those undergoing placebo irradiation. Fisher exact test was used for comparison of categorical data, and nonparametric statistical methods were applied for analysis of continuous data (Mann-Whitney U tests for unpaired data and Friedman analysis for repetitive measurements). Median patient age was 70 years (interquartile range, 56-74 years); 33 (70%) patients were men and 14 (30%) were women. Clinical characteristics and baseline values of acute phase parameters were similar between groups. A statistically significant increase in CRP, SAA, and fibrinogen values was observed after PTA and stent implantation, both in the patients who underwent brachytherapy and in those who underwent placebo irradiation. Compared with placebo irradiation, however, brachytherapy did not significantly reduce any acute phase parameter from baseline to 8, 24, or 48 hours after the intervention (P >.05 for all comparisons). Endovascular brachytherapy did not diminish early vascular inflammation in response to PTA or stent implantation and even induced a trend toward an increased inflammatory response.

Unruptured Intracranial Aneurysms.

Current techniques of percutaneous transluminal coronary revascularization remain limited by the phenomenon of restenosis. The response of the vessel wall to the iatrogenic injury associated with coronary interventions is a complex and multifactorial process. Experimental and clinical studies suggest that a combination of different mechanisms, such as (1) smooth muscle cell (SMC) proliferation and migration (neointimal hyperplasia), (2) vascular remodeling, and (3) thrombus formation and incorporation, may contribute to the development of restenosis.1 Risk factors for restenosis have been analyzed in a large number of studies and can be categorized into lesion-, procedure-, or patient-related variables. Although consistent results have been published regarding lesion- and procedure-related factors, patient-related factors are less well characterized. Diabetes has long been recognized to be a major risk factor for restenosis after balloon angioplasty.2 3 However, studies that have demonstrated interlesion dependence of restenosis in patients who undergo multilesion intervention (the likelihood of restenosis for a lesion being higher when another companion lesion has also developed restenosis) have provided evidence for the existence of other patient-related factors.4 Evidence of prior cytomegalovirus (CMV) infection in adults is very common and usually asymptomatic. High titers of CMV antibodies are more frequent in patients with atherosclerotic disease than in control patients.5 More than …