Balloon pumps

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. 

Hypovolemia, intraprocedural volume depletion, use of large volumes of contrast, and intra-aortic balloon pump... 

The intraaortic balloon pump (IABP) is typically employed in patients with advanced HF who do not respond adequately to drug therapy, such as those with intractable myocardial ischemia or patients in cardiogenic shock. 

Interaction parameters for polymer blends, 20 322 in surfactant adsorption, 24 138 Interaortic balloon pump, 3 746 Intercalated disks, myocardium, 5 79 Intercalate hybrid materials, 13 546-548 Intercalation adducts, 13 536-537 Intercalation compounds, 12 777 Intercritical annealing, 23 298 Interdiffusion, 26 772 Interdigitated electrode capacitance transducer, 14 155 Interesterification, 10 811—813, 831 Interest expense, 9 539 Interface chemistry, in foams, 12 3—19 Interface metallurgy materials, 17 834 Interfaces defined, 24 71... 

Siloxane-containing devices have also been used as contact lenses, tracheostomy vents, tracheal stents, antireflux cuffs, extracorporeal dialysis, ureteral stents, tibial cups, synovial fluids, toe joints, testes penile prosthesis, gluteal pads, hip implants, pacemakers, intra-aortic balloon pumps, heart valves, eustachian tubes, wrist joints, ear frames, finger joints, and in the construction of brain membranes. Almost all the siloxane polymers are based on various polydimethylsiloxanes. 

Kantrowitz A. Origins of intraaortic balloon pumping. Ann Thorac Surg 1990 Oct 50(4) 672-674... 

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... 

There are several other commercial products containing segmented polyurethane (SPU) such as pellethane or cardiothane. These SPUs are widely recognized to possess notable biomedical properties as materials for artificial heart and intra-aortic balloon pumping (IABP), and also as coating materials for pacemaker-lead insulators (See Sect. 4.1). 

Preventing CIN is of particular importance in patients with diabetes and chronic kidney disease, as these are two of the most powerful independent risk factors for CIN (77), Diabetics are more susceptible to (CIN) than are the nondiabetics, and diabetics with pre-existing chronic kidney disease (CKD) are at even greater risk (78). In a recently proposed CIN risk-scoring system, patient characteristics such as diabetes, age >75, chronic congestive heart failure, admission with acute pulmonary edema, hypotension, anemia and chronic kidney disease and various procedure-related characteristics including increasing volumes of contrast media, and intra-aortic balloon pump use were all found to reliably contribute to increased risk (79). 

Diabetes is a major risk factor for deterioration in renal function after angiography (2,7,13). Other factors variably associated with increased rates of CIN include age over 75 years, anemia, female gender, periprocedural volume depletion, heart failure, cirrhosis, hypertension, proteinuria, concomitant use of nonsteroidal anti-inflammatory drugs, and intra-arteriai injection (2,4,5,7,10,13,14,19,43,44). In the setting of acute myocardial infarction or PCI, hypotension or use of an intra-aortic balloon pump has been associated with a higher rate of acute renal failure after exposure to a contrast medium (13,50). Finally, high doses of CM also increase the likelihood of renal dysfunction (51). 

Anemia baseline hematocrit value <39% for men and >36% for women congestive heart failure class III/1V by New York Heart Association classification and/or history of pulmonary edema Hypotension systolic blood pressure <80mmHg for at least 1 hr requiring inotropic support with medications or intra-aortic balloon pump (IABP) within ... 

In this study, we have attempted to obtain a detailed, quantitative estimate of the surface chemical composition of two commercially available polyurethanes, i.e., Biomer and Avcothane, which have demonstrated a reasonable degree of blood compatibility. For example, Avcothane has been used as an intraaortic balloon pump for post-operative patients (5). Biomer also has been successfully used for artificial heart components in calves (14). 

Figure 2. Difference reflection IR spectra of substrate side of Avcothane intraaortic balloon pump with KRS-5 reflection plate (a) without a barrier film, (b) with a barrier film of thickness 0.65 /x (19)...

The use of techniques of circulatory support (extracorporeal oxygenation and intra-aortic balloon pump) in seven cases of overdose with antidysrhythmic drugs (disopyramide, flecainide, prajmaline, and quinidine) has been reviewed (62). 

A 32-year-old man became deeply comatose, with intraventricular conduction disturbances, after taking dextropropoxyphene 4.6 g. Treatment-resistant seizures lasted for hours. He was treated with an intra-aortic balloon pump and a continuous infusion of milrinone for 7 days and recovered fully. 

Gillard P, Laurent M. Dextropropoxyphene-induced cardiogenic shock treatment with intra-aortic balloon pump and milrinone. Intensive Care Med I999 25(3) 335. 

HLA = human leukocyte antigens PRA = intraaortic balloon pump. 

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. 

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). 

---