Catheterization and Cardiovascular Diagnosis 22:56-59 (1 991)

Coronary Balloon Angioplasty Through Diagnostic 6 French Catheters

Ramon Villavicencio, MD, Philip Urban, MD, Thierry Muller, MD, Josiane Favre, RN, and Bernhard Meier, MD

We investigated the use of ultralow profile balloon catheters (Scimed ACE, USCl Probe, Cordis, Orion) for coronary angioplasty through 6 French diagnostic catheters (Schnei- der, Cordis). Contrast injection was assisted with a Hercules pump (Cordis) in all cases. During 21 procedures, angioplasty of 27 lesions in 20 selected patients was attempted (1.3 lesion/procedure). Twelve lesions were in the right, 10 in the left anterior descending, and 5 in the left circumflex coronary artery. Balloon size varied between 2.5 and 3.5 mm. Twenty lesions could be successfully dilated (74%) through the 6 French catheter and 7 lesions required an exchange to a 7 French angioplasty guiding catheter. For 5 cases, another balloon was also necessary to complete the procedure. The final overall success rate was 100% per patient and per lesion and there were no major complications. Despite the small internal catheter lumen (1.22 mm) coronary visualization was adequate, and mechanical support was good. Failures of 6 French catheters were attributed to insuffi- cient torque control and excessive friction when the balloon crossed the tapered end of the diagnostic catheter.

Coronary angioplasty through a diagnostic 6 French catheter is feasible and may represent a reasonable alternative for simple cases that are done during the same ses- sion as the diagnostic angiography. Once available, 6 French high flow angioplasty guid- ing catheters without a tapered tip should improve success while retaining the advantage of a small femoral puncture site.

Key words: coronary artery disease, catheterization techniques, percutaneous translu- minal coronary angioplasty

INTRODUCTION

When coronary artery balloon angioplasty was first introduced into clinical practice 13 years ago [ l ] , the usual external caliber of the guiding catheters was 9.4 French (3.1 mm). Such a diameter was a consequence of both the thick walls of the early solid teflon catheters, and the large internal lumen required to accommodate the high profile balloon catheters that were used. The design afforded the rigid mechanical backup that was necessary to help cross the stenosis with the early bal- loons. Over the years, braided teflon-coated polyure- thane guiding catheters were introduced with outer di- ameters of 9 French (3 mm) or 8 French (2.7 mm) and rapidly became the standard [2,3]. They allow deeper intubation of the coronary ostia than the original larger catheters and 'thus compensate for the loss in intrinsic backup power. More recently, following the remarkable improvements in balloon catheter profile, 7 French (2.3 mm) guiding catheters have been introduced, that will accommodate most of the recent low-profile balloon catheters, particularly if they feature a small (<4 French) shaft. There are several advantages of small diameter

guiding catheters: ( 1 ) the femoral puncture hole is smaller and the risk of local bleeding is decreased, (2) wedging of the catheter in the coronary ostium is less likely, (3) deep intubation of the coronary artery with the guiding catheter is easier, and (4) when angioplasty is done following a diagnostic procedure, the same femoral introducer can be used.

Since balloon-on-a-wire dilatation catheters with ul- tralow profile are now available from several manufac- turers, we investigated the use of 6 French (2 mm) di- agnostic catheters for selected coronary angioplasty procedures, to determine the feasibility, advantages, and limitations of such an approach.

From the Cardiology Center, University Hospital, Geneva, Switzer- land.

Received April 25, 1990; revision accepted August 6 , 1990.

Address reprint requests to Dr. Philip Urban, Cardiology Center, Uni- versity Hospital, 121 1 Geneva 4, Switzerland.

0 1991 Wiley-Liss, Inc.

Angioplasty Through 6F Diagnostic Catheters 57

was checked by further contrast injection while the bal- loon was either across the lesion, pulled back just prox- imal to it with the guidewire still beyond, or advanced completely beyond it. When the result was judged satis- factory, the balloon was withdrawn. In the majority of cases, the balloon did not pass easily through the tapered tip of the diagnostic catheter upon withdrawal. The sys- tem then had to be removed as a whole and the balloon was manually helped through the tip before the diagnos- tic catheter could be reintroduced for a final angiogram.

METHODS

Between June 1989 and February 1990, coronary bal- loon angioplasty of 27 lesions was attempted through a 6 French diagnostic catheter using balloon-on-a-wire sys- tems. A successful procedure was defined as a residual stenosis of less than 50%. Patients with calcified, long, or ulcerated lesions, for whom it was anticipated that several balloons, bail-out catheters, or stents might be required, were not considered candidates.

Patients

Angioplasty was done by the femoral route in 13 male and 7 female patients with a mean age of 61 2 12 years (range 41 to 78 years). Twenty-one procedures in these 20 patients were attempted, (1 patient was included twice because of restenosis of the same lesion). Eight proce- dures were done for patients with myocardial infarction within 30 days prior to the procedure, 11 for unstable angina, and 2 for stable New York Heart Association class I1 angina. In 17 procedures, dilatation of a single lesion was attempted, and in 4 procedures more than 1 lesion (2 cases with 3 lesions in 3 vessels, 2 cases with 2 lesions in 2 vessels). Overall 27 lesions were attempted with a mean of 1.3 lesions/patient. There were 12 lesions in the right coronary artery, 10 in the left anterior de- scending coronary artery or a diagonal branch, and 5 in the left circumflex coronary artery. Eight lesions (30%) were in the proximal segment of the target vessel, 14 (52%) in the mid-portion, and 5 (18%) in the distal seg- ment. Four lesions (15%) were restenoses after prior an- gioplasty.

There were no total occlusions and no lesion was con- sidered to be of complex morphology. Mean lesion se- verity was 81 * 12%.

Angioplasty Equipment

The balloon catheters used were ACE (Scimed), Probe or New Probe (USCI), and Orion (Cordis) catheters, with the following balloon sizes: 2.5 mm in 13 cases, 3.0 mm in 12, and 3.5 mm in 2. The catheters used for guiding were 6 French (2 mm) Judkins or multipurpose diagnostic catheters with an inner lumen of 1.22 mm, no teflon coating, and a tapered tip (Schneider Softip in 19 cases, Cordis in 2). A C02-powered pneumatic Hercules assistance device (Cordis) was used to facilitate contrast injection [4].

Procedure

The procedure did not differ from our usual angio- plasty practice [ 5 ] . Advancement of the balloon catheter was done under fluoroscopy guidance with intermittent contrast injections.

After inflation of the balloon, the immediate result

RESULTS

The procedure was successful in 20 of 27 lesions with- out need for crossover to a different system, giving a success rate of 74% for the 6 French catheters. The mean residual stenosis was 16% 2 9. The success rate was 64% for the first 14 lesions (9 of 14) and 84% for the last 13 lesions attempted (1 1 of 13). In 7 cases, the procedure was unsuccessful due to failure to reach or to cross the lesion with the balloon. A change to a 7 French guiding catheter (using the same balloon in 2 and another balloon in 5 cases) allowed successful completion of the proce- dure for all target lesions. The overall success rate in this selected group was thus loo%, and no major complica- tion was observed. One patient (5%) developed a mod- erate hematoma at the femoral puncture site while the sheath was still in place but did not require blood trans- fusion and could be discharged the day after the proce- dure. On no occasion was wedging of the 6 French cath- eter observed in the coronary ostium and deep selective intubation of the proximal coronaries was possible when- ever needed to afford sufficient backup. The same fem- oral introducer used for diagnostic angiography was used for the angioplasty in all procedures.

DISCUSSION

Our data demonstrate the feasibility of coronary bal- loon angioplasty through 6 French diagnostic catheters for a selected group of patients. The success rate per lesion was 74%, and all failed attempts could be dilated through a 7 French catheter during the same procedure with no major complications, yielding a final overall success rate of 100%. These results are in accord with two earlier case reports [6,7] and deserve the following comments:

Although, as we gained experience in patient selection, our success rate increased to 84%, the 6 French approach is clearly less successful than a more conventional tech- nique [8], especially for a selected group of patients with “simple” lesions. The major limitation of the technique is the tapered tip of the diagnostic catheter. This is well suited to minimize trauma to the coronary ostium during

58 Villavicencio et al.

Fig. 2. (a) Right anterior oblique view of the left anterior de- scending coronary artery of a 61-year-old man demonstrating good visualization with the deflated balloon-on-a-wire across the lesion (arrows point to proximal marker and radiopaque distal wire). (b) Result after angioplasty.

diagnostic coronary angiography , but opposes some re- sistance to the passage of the balloon catheter. It limits torque control when a side branch or the target lesion itself must be negotiated by the extremity of the wire with the balloon straddling the tip of the catheter.

Retrieval of the balloon inside the catheter was a fre- quent problem because of loss of balloon profile (winging) after one or several inflation/deflation cycles. When gentle traction did not allow withdrawal of the balloon inside the catheter, the entire system had to be removed as a sheath and the balloon was then helped manually back through the 0s- tium of the catheter or severed if no longer needed.

Fig. 1. (a) Right anterior oblique view of the right coronary artery of a 38-year-old man following inferior myocardial infarc- tion. There is a tight proximal stenosis. (b) Dilatation with the 3.0 mm balloon. (c) Result after angioplasty.

through the

Angioplasty Through 6F Diagnostic Catheters 59

improve the success rate and allow this approach to be more widely recommended for routine clinical use.

This drawback was never a clinical problem, however, since angiographic visualization of the target vessel and angioplasty result was always excellent when the de- flated balloon was either across the lesion or beyond it (Figs. 1 and 2).

Manipulation of the 6 French diagnostic catheter is not fundamentally different from that of the usual guiding catheters, but the lack of tip wedging in the coronary ostium and the increased flexibility make it possible to seat the catheter very deeply in the target vessel when necessary and thus obtain good backup support.

For selected patients with straightforward lesions, cor- onary angioplasty can be done through a 6 French diag- nostic catheter with an acceptable success rate. It thus appears to be an appropriate alternative when the angio- plasty procedure is done during the same session as the diagnostic angiogram since it allows the same small di- ameter femoral introducer to be used. In addition, the expense of a guiding catheter is avoided. In case of tech- nical failure, a 7-French guiding catheter can be substi- tuted. Once high flow 6 French teflon-coated guiding catheters without a tapered tip become available, they may allow the use of over-the-wire balloons and thus

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