Balloon catheter inflation

Zwergel et al. (1991) developed an intact canine model to measure renal pelvic pressure after complete ureteral obstruction with a balloon catheter inflated in the distal ureter. 

The ureter can be temporarily completely occluded using a balloon catheter inflated with contrast in the proximal ureter. 

Note Balloon angioplasty is a noninvasive procedure in which a balloon-tipped catheter is introduced into a diseased blood vessel. As the balloon is inflated, the vessel opens further, allowing for placement of a stent and improved flow of blood.]... 

A more advanced catheter is the Dispatch catheter, which is an infusion-perfusion balloon catheter that forms a separate compartment adjacent to target vessel wall when the catheter is inflated (Tahlil et al.,... 

Slow application of 0.2-l.5mL of alcohol through the inflated balloon catheter induces necrosis of the myocardium, which is seen as an obvious contrast enhancement on echocardiography. If the gradient post instillation of alcohol remains above 30 mmHg, the balloon may be positioned more proximally in the vessel or a second septal perforating artery may be treated in the same way,... 

Complications reported with this type of intervention are rare, Rupture of the annulus is reported. The tricuspid valve may also be damaged if a large diameter balloon catheter has been passed inadvertently through the tricuspid valve chordae. After inflation, the balloon is relatively bulky and as it is removed the tricuspid valve apparatus may be disrupted causing regurgitation. A procedure-associated death rate of 0.24% and a major complication rate of 0.35% were found in a large study comprising 822 balloon pulmonary valvuloplasty procedures (15). 

Approaching the aortic valve with a catheter can be achieved via the venous (antegrade, transseptal) or the arterial routes (retrograde) (37,38). The delivery assembly is positioned within the diseased native valve. Before expansion of the valve mounted balloon rapid pacing (>200 beats/min) is performed to lower stroke volume during the implantation sequence. The balloon is inflated fixing the stented valve to the implantation site. Immediately after balloon deflation... 

Figure Ic. With catheter in place balloon is inflated to block blood flow and catheter tip freezes damaged tissue.

The brain requires an especially copious blood supply. Large arteries in the side and back of the neck carry blood to the brain, but when these arteries become narrowed or blocked by fatty deposits (a condition called atherosclerosis), the blood supply to the brain may be reduced to an insufficient amount. A balloon catheter may be used by the physician to clear the blockage. In this procedure, called angiography, a catheter is guided to the site of blockage. The tiny balloon on the end of the catheter is inflated to press the blockage out of the way. 

Figure 4 Balloon angioplasty with and without stent deployment, (a) In balloon angioplasty, a thin catheter is threaded through the circulatory system until the uninflated balloon at its tip penetrates the diseased artery at the point of blockage, as shown in the top diagram. The balloon is then inflated to expand the artery, as shown in the middle, before being deflated and withdrawn to allow blood flow to resume (bottom panel). (b) An increasingly common feature of angioplasty involves deployment of an expandable wire structure to help keep the artery from collapsing after the balloon is withdrawn. The procedure is the same as in (a), except that a wire stent is placed over the balloon before insertion (top). The stent expands when the balloon is inflated (middle) and retains its expanded form after the balloon and catheter are withdrawn (bottom), remaining in place after the procedure is complete to provide a permanent structural support for the arterial wall.

A balloon catheter is placed per rectum (10 F-18 F). Many operators inflate the balloon on the Foley catheter but this is not universal practice and caution should be used when inflating a balloon catheter in the rectum because of the reported risk of mucosal ischaemia. The buttocks are subsequently taped or gripped firmly to complete a good seal at the anus. Air is then introduced into the distal colon, with a manometer or other monitoring device present on the system to ensure safe and constant pressures of air. The progress of the air (and the reduction of the intussusceptum) is closely observed under fluoroscopic guidance (Fig. 6.8a). It is usual practice to include the whole abdomen within the field of view so as not to miss a perfora-... 

London RL, Trotman RW, DiMarino AJJr, Oleaga JA, Frei-man DB, Ring EJ et al (1981) Dilatation severe oesophageal strictures by an inflatable balloon catheter. Gastroenterology 80 173-175... 

Intra-aortic balloon piunps A balloon catheter inserted in the descending aorta and alternately inflated and deflated timed to the EKG in order to assist the ventricular pumping. 

Stents can be divided into two main groups on the basis of the method of expansion. Balloon-expandable stents either arrive premounted on a balloon angioplasty catheter or are mounted by the doctor prior to the procedure. A balloon catheter with inflation apparatus is shown in Fig. 20.3. While mounted, the stent is moved into place and the balloon inflated to expand the stent to the desired diameter. Figure 20.4 illustrates the placement and inflation procedure for balloon-expandable stents. In contrast, self-expanding stents come premounted or sheathed. Once deployed to the treatment area, the sheath is pulled back, allowing the stent to expand to its predetermined diameter. Balloon-expandable stents can be further subdivided into slotted-tube and coil-based designs (Oes-terle et al., 1998). 

FIGURE 20.3 A balloon catheter and inflation pump are shown. Balloon catheters are used to widen stenosed or narrowed vessels and to expand stents. The balloon is often inflated with a mixture of saline and contrast... 

The existence of a feedback loop between glomerular filtration rate and tubular reabsorption has been established. Glomerular filtration and sodium reabsorption in the proximal tubules increase and decrease together. The following type of experiment best illustrates this relationship. Saline is administered to a dog to expand the extracellular fluid volume and induce sodium excretion. When a balloon catheter introduced in the femoral artery of the dog is inflated to reduce arterial pressure from 170 to 90 mm Hg, filtration drops 10%, but reabsorption drops 50%. The adjustment of reabsorption to filtration is not affected by decerebration, adrenalectomy, hepatectomy, or renal denervation. 

One such catheter, a balloon-tipped catheter, is used to open a blocked artery. When the catheter with a balloon fitted on its tip reaches the site of a blockage, the balloon is inflated to enlarge the interior of the artery by flattening plaque deposits s ainst the vessel wall. In 1977, German cardiologist Andreas Gruentzig performed the first balloon angioplasty in a human in Zurich, Switzerland. 

Perhaps the simplest catheter is a thin plastic or rubber tube, for example a standard 14F rectal tube (Jacques Nelaton rectal catheter Rusch, Bucks, UK) or a Foley catheter. The former was shown to be as effective as a standard inflatable rectal balloon catheter (Trimline DC E-Z-EM, Westbury, NY) for achieving adequate distension (Taylor et al. 2003). Alternatively, the Foley catheter is almost ubiquitous and can be used effectively when attached to a bulb insufflator. The soft tip allows safe insertion and it... 

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