Heart assist balloon pumps

Nyilas, the developer of Avcothane R, snythesized a copolymer of polyurethane and polydimethyl siloxaneW which is blood compatible and used in the making of heart assist balloon pump s. 

Economic Aspects. The cardiovascular devices market is estimated to be approximately 2.9 biUion annually on a worldwide basis. This market can be further segmented as follows angiography and angioplasty, 644 x 10 arrhythmia control, 1500 x 10 cardiovascular surgery, 700 x 10 cardiac assist (intra-aortic balloon pump), 80 x 10 and artificial hearts, which are experimental. 

Other efforts have led to the development of ventricular assist devices to support the heart for several months and intra-aortic balloon pumps (lABPs) which are widely used to unload and stabilize the heart. 

Ca.rdia.c-AssistDevices. The principal cardiac-assist device, the intra-aortic balloon pump (lABP), is used primarily to support patients before or after open-heart surgery, or patients who go into cardiogenic shock. As of the mid-1990s, the lABP was being used more often to stabilize heart attack victims, especially in community hospitals which do not provide open-heart surgery. The procedure consists of a balloon catheter inserted into the aorta which expands and contracts to assist blood flow into the circulatory system and to reduce the heart s workload by about 20%. The disposable balloon is powered by an external pump console. 

Burkhoff D, Cohen H, Brunckhorst C, O Neill WW. A randomized multicenter chnical study to evaluate the safety and efficacy of the TandemHeart percutaneous ventricular assist device versus conventional therapy with intraaortic balloon pumping for treatment of cardiogenic shock. Am Heart J 2006 152 469el-469e8... 

The intraaortic balloon pump (lABP) is a frequently used form of mechanical circulatory assistance and typically is employed in patients with advanced heart failure who do not respond adequately to... 

The simplest heart assist device is the intraaortic balloon pump (lABP) which consists of two small PEUU balloons mounted on a hollow catheter that is about 30 cm long. The distal occluding balloon is 18 mm in diameter, and the proximal pumping balloon is 14 mm in diameter. The device is inserted into the aorta via the femoral artery and connected to a pump that then expands and contracts the balloons in rhythm with the heart beat. This prosthesis is considered to be the best heart assist device because it is simple in design and easy to insert. Improved circulation does occur in about three-fourths of the patients, but the mortality rate still remains high (65-90%) in cases of refractory cardiogenic shock. The lABP is used over 15,000 times annually (51. 52). 

The most widely used heart assist device, other than the heart-lung machine routinely used in surgery, is the intraaortic balloon pump (lABP) which consists of a PEUU balloon mounted on a hollow catheter. The lABP is Inserted into the aorta via the femoral artery and is then expanded and contracted by an external pumping system to match the heart beat. While this device does provide significant Improvement in circulation and also allows the heart to rest partially after a myocardial infarction, the mortality rate is still 65-90 ( 8). 

Artificial circulatory support can be broadly classified into two categories. The first category is for those patients who undergo open heart surgery to correct valvular disorders, ventricular aneurysm, or coronary artery disease. In several cases, the heart may not recover sufficiently after surgery to take over the pumping action. In such patients ventricular assist devices are used as extracorporeal devices to maintain circulation until the heart recovers. Other ventricular assist devices include intra-aortic balloon pumps as well as... 

The most commonly used means of mechanical circulatory support is the intra-aortic balloon pump (lABP). In 1990, it was estimated that lABP therapy was provided to 70,000 patients aimually (Kantrowitz, 1990). As described below, the lABP can provide only limited cardiovascular support, as its effects are limited to pressure unloading of the ventricle, in contrast to artificial hearts and ventricular assist devices, which provide volume unloading (Mehlhom et al., 1999). To be effective, the lABP requires that the patient maintain some native pumping capacity, as the movement of blood due to the balloon is minimal. 

It is a device able to evaluate the valve performance in conditions similar both to the physiological ones and to the most common cardiovascular pathologies. Such an apparatus has already been described in detail in a previous paper. Besides testing prosthetic valves, this mock circulatory system can evaluate vascular prosthe-ses, left heart replacement pumps, intraaortic balloon pumps and other circulatory assistance devices. Neither the anatomic complexity nor the physiological behaviour can be exactly reproduced, but the simplicity of use and the good results obtained with this device, show its efficiency. 

Biomaterials have played a vital role in the treatment of cardiovascular diseases, examples of applications including heart valve prostheses, vascular grafts, stents, indwelling catheters, ventricular assist devices, total implantable artificial heart, pacemakers, automatic internal cardioverter defibrillator, intraaortic balloon pump, and more. A key requirement for materials in cardiovascular applications, particularly blood-contacting devices, is blood compatibility, that is, nonthrombogenic. Additional requirements include mechanical and surface properties that are application specific. Surveying the field of polymers used in cardiovascular applications reveals that PUs, polyethylene terephthalate (PET), and expanded PTFE (ePTFE) are the most commonly used. This section will review each of the three polymers followed by a brief introduction of other emerging polymers for use in the cardiovascular area. 

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