Coaxial Balloon Catheter Research Articles

An investigation of PLLA hybrid stent design to overcome thick strut problems

Biodegradable polymer-based stents simultaneously provide scaffolding, drug release, and biodegradation to eliminate chronic inflammation. The most important factors hindering the wide use of these stents are thick struts, low radial strength, and large footprints formed on the inner wall of the artery as a result of stent expansion. Negative Poisson’s Ratio (NPR), also known as the Auxetic design, has shown great potential to provide radial strength with less strut thickness. However, a detailed mechanical evaluation proving improvement in stent performance parameters is not available in the literature. In this study, the performance parameters of two stent designs based on the Auxetic geometry with PLLA were analyzed under in-vivo conditions using an in-silico model consisting of the artery, crimper, and expander FE model. For this purpose, one design utilizes Auxetic unit cell, which is already available in the literature, while the other uses a newly proposed Hybrid design combining Auxetic and Chevron type geometries. Additionally, a specially heated coaxial balloon-catheter system was considered as a deployment tool between glass transition and body temperature, and carried out for thin-strut stent simulations. The Hybrid design is shown to resolve the foreshortening problem of Auxetic design and collapse pressure of commercial PLLA stents. In this present study validates the potential of Hybrid design to overcome problems for polymer-based biodegradable stents.

Comparative Analysis of Methods to Induce Myocardial Infarction in a Closed-Chest Rabbit Model.

Objective. To develop a rabbit model of closed-chest catheter-induced myocardial infarction. Background. Limitations of rodent and large animal models justify the search for clinically relevant alternatives. Methods. Microcatheterization of the heart was performed in 47 anesthetized 3-4 kg New Zealand rabbits to test five techniques of myocardial ischemia: free coils (n = 4), interlocking coils (n = 4), thrombogenic gelatin sponge (n = 4), balloon occlusion (n = 4), and alcohol injection (n = 8). In order to limit ventricular fibrillation, an antiarrhythmic protocol was implemented, with beta-blockers/amiodarone before and xylocaine infusion during the procedure. Clinical, angiographic, and echographic data were gathered. End points included demonstration of vessel occlusion (TIMI flow grades 0 and 1 on the angiogram), impairment of left ventricular function at 2 weeks after procedure (by echocardiography), and pathologically confirmed myocardial infarction. Results. The best arterial access was determined to be through the right carotid artery. The internal mammary guiding catheter 4-Fr was selected as the optimal device for selective intracoronary injection. Free coils deployed prematurely and tended to prolapse into the aorta. Interlocking coils did not deploy completely and failed to provide reliable results. Gelatin sponge was difficult to handle, adhered to the catheter, and could not be clearly visualized by fluoroscopy. Balloon occlusion yielded inconsistent results. Alcohol injection was the most efficient and reproducible method for inducing myocardial infarction (4 out of 6 animals), the extent of which could be fine-tuned by using a coaxial balloon catheter as a microcatheter (0.52 mm) to achieve a superselective injection of 0.2 mL of alcohol. This approach resulted in a 20% decrease in LVEF and infarcted myocardium was confirmed histologically. Conclusions. By following a stepwise approach, a minimally invasive, effective, and reproducible rabbit model of catheter-induced myocardial infarction has been developed which addresses the limitations of rodent experiments while avoiding the logistical and cost issues associated with large animal models.

Combined balloon stent technique with the Scepter C balloon and low-profile visualized intraluminal stent for the treatment of intracranial aneurysms

BackgroundThe ‘balloon-then-stent’ method involves stent placement after completion of a balloon-assisted embolization. The drawback to this technique is that the coil mass achieved during balloon remodeling must be crossed prior...

P-009 Endovascular balloon-augmented embolization of intracranial and cervical arteriovenous malformations using a dual lumen coaxial balloon microcatheter: initial experience

BackgroundTransarterial embolization with ethylene vinyl alcohol copolymer (EVOH) Onyx (ev3, Neurovascular, Irvine, CA) is a popular method for endovascular management of arteriovenous malformations (AVMs) and fistulas. Successful embolization depends on...

Development of a New Coaxial Balloon Catheter System for Balloon-Occluded Retrograde Transvenous Obliteration (B-RTO)

To develop a new coaxial balloon catheter system and evaluate its clinical feasibility for balloon-occluded retrograde transvenous obliteration (B-RTO). A coaxial balloon catheter system was constructed with 9 Fr guiding balloon catheter and 5 Fr balloon catheter. A 5 Fr catheter has a high flexibility and can be coaxially inserted into the guiding catheter in advance. The catheter balloons are made of natural rubber and can be inflated to 2 cm (guiding) and 1 cm (5 Fr) maximum diameter. Between July 2003 and April 2005, 8 consecutive patients (6 men, 2 women; age range 33-72 years, mean age 55.5 years) underwent B-RTO using the balloon catheter system. Five percent ethanolamine oleate iopamidol (EOI) was used as sclerosing agent. The procedures, including maneuverability of the catheter, amount of injected sclerosing agent, necessity for coil embolization of collateral draining veins, and initial clinical results, were evaluated retrospectively. The occlusion rate was assessed by postcontrast CT within 2 weeks after B-RTO. The balloon catheter could be advanced into the proximal potion of the gastrorenal shunt beyond the collateral draining vein in all cases. The amount of injected EOI ranged from 3 to 34 ml. Coil embolization of the collateral draining vein was required in 2 cases. Complete obliteration of gastric varices on initial follow-up CT was obtained in 7 cases. The remaining case required re-treatment that resulted in complete obstruction of the varices after the second B-RTO. No procedure-related complications were observed. B-RTO using the new coaxial balloon catheter is feasible. Gastric varices can be treated more simply by using this catheter system.

A One-Stage Method for Obtaining CT during Arterial Portography and Hepatic Arteriography

We describe a new technique for performing CT during arterial portography (CTAP) and during hepatic arteriography (CTHA) in a one-stage procedure, using a coaxial balloon catheter system and slip-ring CT equipment. This technique was employed in 10 patients with liver neoplasms. Both CTAP and CTHA images were obtained in all patients.

A one-stage method for obtaining CT during arterial portography and hepatic arteriography

We describe a new technique for performing CT during arterial portography (CTAP) and during hepatic arteriography (CTHA) in a one-stage procedure, using a coaxial balloon catheter system and slip-ring CT equipment. This technique was employed in 10 patients with liver neoplasms. Both CTAP and CTHA images were obtained in all patients.

Varicoceles: distal occlusion with coaxial catheter system.

A coaxial balloon catheter system with an inner catheter and a steerable wire for selective catheterization and occlusive therapy is described. The system was designed primarily for distal sclerotherapy of varicoceles but can also be used in other arterial or venous systems.

Coaxial balloon-catheter device for treatment of neonates and infants.

Lack of preservation of the femoral artery after therapeutic angiography in neonates and infants has been a major obstacle to the repeated use of coaxial catheter systems. A catheter system is described that, because of its small size, has proved successful in the treatment of intracranial vascular malformations in neonates and infants by preservation of the femoral artery for future use.

Embolization of small vessels with a double-lumen microballoon catheter. Part I: Design and construction.

Existing coaxial balloon catheters cannot be passed through the smaller catheters used for superselective angiography; nor can they be used by themselves for selective catheterization, as the balloons are easily damaged. The authors describe the principles and construction of double-lumen catheters ranging from 0.45 to 0.85 mm in outer diameter, which may be passed through 4.1-6.0 F catheters to engage smaller vessels. Double-lumen catheters with an outer diameter of 0.45-0.56 mm permit injection of ethanol or a mixture of isobutyl-2-cyanoacrylate, iophendylate, and tantalum powder. The 0.85-mm size is best suited for low-viscosity silicone rubber opacified with tantalum.