New preshaped catheter for investigation of aortic stenosis by femoral approach: a study of 100 cases

A computer assisted method for guide-wore and catheter evaluation

We developed a method for testing guide wires and catheters that realistically evaluates the forces applied to anatomical structures by these instruments during urological procedures. The placement of guide wires and catheters to gain access to the upper urinary tract can induce undesirable stress on the tissue. Previous studies have characterized wire/catheter performances base on their physical properties, such as stiffness and friction coefficient. However, the results of these studies do not directly quantify their effect on the tissues. Additionally, individual physical properties do not entirely characterize the behavior of the wire/catheter ensemble. Our model utilizes a computer-controlled test stand that simulates the urological environment by including a tortuous path and a stone obstruction. Experimental results indicate that the method shows significant promise in reflecting wire/catheter performance data in congruence with reliable real-life measures of stress upon relevant anatomical structures. Furthermore, due to the modularity of the approach, the model can be easily reconfigured to simulate environments from other medical fields.

An evaluation method for the mechanical performance of guide-wires and catheters in accessing the upper urinary tract

The placement of guide-wires and catheters to gain access to the upper urinary tract can induce undesirable stresses on tissues. Previous studies have characterized the performance of wires and catheters by evaluating their physical properties such as stiffness and friction coefficient. However, the results of these studies do not directly quantify the wire's effects on tissues. Furthermore, the individual physical properties of wires and catheters investigated in previous studies cannot be simply summed up to characterize the behavior of an entire wire/catheter ensemble. This paper presents an objective method for testing guide-wires and catheters that estimates the forces applied by these instruments to anatomical structures during urological procedures. Our model utilizes a computer-controlled test stand that simulates a urological environment by including a tortuous path and a stone obstruction. Experimental results using this model show significant promise in reflecting the performance of guide-wires and catheters measuring the stress exerted upon relevant anatomical structures. Furthermore, due to the modularity of the approach, the model can be easily reconfigured to simulate environments relevant to other medical fields.

A rapid, effective technique for retrograde crossing of valvular aortic stenosis using standard coronary catheters

Retrograde crossing of valvular aortic stenosis can be challenging even to experienced angiographers. In 446 of 447 consecutive patients with aortic stenosis catheterized during the past 3 years, a technique using a standard Judkins right coronary catheter and a floppy straight tipped guide wire was successful in rapidly and efficiently crossing these pathologically distorted valves in retrograde fashion. Once the valve was crossed, the coronary catheter was replaced with a pigtail catheter for pressure and ventriculography. The majority of these valves required less than 2 min to cross using this technique. This method is valuable in limiting the time required for catheterization, thus helping to reduce procedure related morbidity in these oftimes critically ill patients.

Multipurpose A2 catheter approach to left heart catheterization in severe aortic stenosis

An approach has been presented for the performance of right and left heart catheterization, left ventriculography, supravalvular aortography, and coronary arteriography utilizing a #8 French, A2 multipurpose catheter. Using the manipulations described herein, the left ventricle was entered in 96% of the patients. The multipurpose catheter is an excellent catheter for left ventriculography, negating the need for catheter exchange once the left ventricle has been entered. Likewise, this catheter provides excellent supravalvular aortography and selective coronary arteriography supplemented as needed with preformed coronary arteriographic catheters. This method provides a very safe, efficient approach to the performance of complete heart catheterization in patients with clinically significant aortic stenosis.

A new catheter design for use in patients with critical aortic stenosis

A new catheter that facilitates catheterization in patients with severe aortic stenosis is described. The catheter design is capable of high-pressure injections for left ventriculography, but it maintains maneuverability and has an end hole for use with a guide wire in traversing tightly stenotic valves. Experience with this catheter in 23 patients confirmed that good-quality ventriculograms are obtained after left ventricular entry. Twenty-two of 23 patients with aortic stenosis were studied entirely with this catheter; in only one case were attempts to cross the valve unsuccessful, both with this and other catheters. In conclusion, this new catheter is recommended for routine use in patients with suspected severe aortic stenosis.

Retrograde transfemoral catheterization of the left ventricle in children with aortic valve stenosis

In 19 consecutive children with aortic valve stenosis, the left ventricle was entered retrogradely with a Gensini catheter guided by a tip-deflector guidewire which could produce any desirable degree of curvature at its tip. In all patients, the aortic valve was retrogradely traversed for measurement of the pressure gradient (mean gradient = 53 mmHg, mean valve area = 0.36 cm2), and left ventriculography. No complications were encountered. This technique is safe, simple, and effective in retrograde catheterization of the left ventricle in children with aortic stenosis.

Percutaneous transfemoral catheterization in aortic stenosis with a USCI Sones catheter curve A type 1 (7540)

We report our experience with the use of a USCI Sones catheter curve A type 1 (7540) to cross the aortic valves of 45 patients with clinically significant aortic stenosis. The technique was successful in all our patients with a fluoroscopic time of less than 3 min. A gradient of up to 200 mmHg across the aortic valve area was recorded, and the smallest valve area calculated was less than 0.2 cm2. The method obviated the need for a guidewire and satisfactory left ventriculograms were obtained. No major complication was observed. We conclude that the technique is a simple, rapid, and safe means of obtaining left ventricular hemodynamic and angiographic information in patients with aortic stenosis of various degrees of severity.

A modified catheter system for retrograde left ventricular catheterization in aortic valve stenosis

Conventional retrograde catheterization of the left ventricle using a single large catheter through severely stenotic aortic valves or prostheses has recognized difficulties. An alternative method is described. This method incorporates a coronary angioplasty guide catheter and coronary probing catheter attached to separate pressure transducers allowing simultaneous recording or aortic and LV pressures. This technique was used in seven patients with aortic stenosis in whom a conventional approach had failed. The movable probing catheter permits alterations of the catheter orientation and angulation while the guiding catheter stabilizes the system within the high velocity jet formed in the ascending aorta. This stabilization and the small size of the coronary probing catheter permit exploration of the valve surface and allow for insertion through a tilting disc valve or a severely stenotic valve without significantly altering hemodynamic function. In our laboratory this technique allowed us safely and reliably to assess aortic valve dynamics in each of the patients in whom the technique was attempted without resorting to either transseptal or direct left ventricular puncture.

Recent experience with transeptal catheterization

We report our recent experience of 207 consecutive transeptal catheterizations performed in the following groups of patients: aortic valve disease in 152, mitral valve disease in 20, combined aortic and mitral valve disease in 11, hypertrophic obstructive cardiomyopathy in 11, assessment of prosthetic cardiac valves in nine, and four miscellaneous. Transeptal catheterization failed in 20 patients. There was no attempt to advance the transeptal catheter from the left atrium into the left ventricle in 18 patients, and failure to advance the transeptal catheter from the left atrium into the left ventricle occurred in 13 patients. Transeptal catheterization was achieved in a mean time of 9.7 +/- 4.6 SD min. There were no deaths, two major and four minor complications. We conclude that transeptal catheterization remains a useful technique that in experienced hands is both rapid and safe.

A safe and rapid technique for retrograde catheterization of the left ventricle in aortic stenosis

The present report describes our experience in 82 patients with a pigtail-straight guide wire system for crossing stenotic aortic valves. The technique was successful in 95% of all the attempts and the average fluoroscopic time was three minutes. There were no major complications of the procedure. The technique allowed for consistent, high quality ventriculograms in 73 patients enabling us to define the severity of concomitant mitral regurgitation in 27 of the patients, as well as a preoperative ejection fraction in all 73 patients. We conclude that the technique as described is a safe and efficient way to obtain both hemodynamic and angiographic information at minimum risk in patients with severe aortic stenosis.

A safe, rapid method of transfemoral retrograde left ventricular catheterization in valvular aortic stenosis

We report our experience with the use of a standard left Amplatz coronary catheter and a guidewire to cross the aortic valve in 34 patients being evaluated for valvular aortic stenosis. A number of 2 Amplatz left coronary catheter inserted via the femoral artery was positioned above the noncoronary aortic valve cusp with the tip aligned toward the aortic valve. This catheter allowed a soft-tipped, Teflon-coated guidewire to be guided through the aortic valve orifice. The catheter was then advanced over the guidewire into the left ventricle. This technique was successful within six minutes in 32 of 34 patients (94%). The stenotic aortic valve was crossed in less than two minutes in 15 patients (42%) and in less than four minutes in 31 (91%). The aortic valve was not crossed in two patients. Twenty-one patients (62%) had an aortic valve area of less than 0.75 cm2. There were no complications. We conclude that this technique provides a method for safe, rapid transaortic left ventricular catheterization in patients with aortic stenosis of all degrees of severity.