Computed Tomography During Experimental Balloon Dilatation For Calcific Aortic Stenosis. A Look into the Mechanism of Valvuloplasty

Thin-slice contiguous computed tomographic scanning was performed in four postmortem hearts with calcific aortic valve stenosis (mean weight: 583 ± 78 g; mean age: 65 ± 10 years) before, during, and after balloon valvuloplasty. Balloons of increasing diameter (15–19 mm single balloons, and 3 × 12-mm trefoil-shaped balloon) were positioned across the aortic valve and manually inflated to pressures of 3 to 4 atmospheres. During inflation of the 3 × 12-mm balloon a larger residual orifice, potentially free for blood passage, was observed in the two cases with bicuspid valves and in one case with a fused tricuspid valve, while the reverse was noted in one case with a tricuspid valve without fusion. In most cases valvular orifice enlargement only occurred with larger diameter balloons. After valvuloplasty aortic valve area increased from 0.72 (range 0.20–0.95) cm² to 2.36 (range 0.95–3.14) cm². The smallest orifice enlargement after dilatation occurred in case 1, where valvular calcified deposits had the largest volume and the highest computed tomographic attenuation value. In each patient macroscopic changes (fracture of nodular calcifications, commissural splitting, tearing of the central raphe) were noted. No calcium dislodgement or aortic ring damage was observed. In autopsy specimens computed tomography provided accurate evaluation of aortic valve morphology, extent of valve calcification, balloon-leaflet relationship during inflation, and effects of the dilatation on valve leaflets and commissures. Advances in computed tomographic cardiovascular imaging may achieve similar results in the clinical setting, and allow a more rational, individualized approach to the valvuloplasty procedure. (J Interven Cardiol 1988:1:2)     

Aortic valvuloplasty of calcific aortic stenosis with monofoil and trefoil balloon catheters: practical considerations

Summary In order to evaluate the relation between balloon design (monofoil, trefoil) and valvular configuration, experimental aortic valvuloplasty was performed in four post-mortem hearts with calcific aortic stenosis of various morphology. The degree of obstruction of the aortic orifice was assessed by computed axial tomography during inflation of monofoil 15 and 19 mm and trefoil 3×12 mm balloon catheters. We also evaluated the hemodynamic repercussion of balloon inflation (fall in systolic aortic pressure) in four elderly patients with acquired aortic stenosis who underwent a percutaneous transluminal aortic balloon valvuloplasty, with stepwise increasing balloon sizes of 15 mm, 19 mm and 3×12 mm, as during ourin vitro experiments, and who underwent aortic valve replacement later on. In these patients, we correlated the anatomy of the excised aortic valves with the retrospective analysis of aortic pressure curves recorded during previous valvuloplasty procedures.Our experimental and clinicopathological observations showed that the degree of obstruction of the aortic orifice in post-mortem specimens and the tolerance to balloon inflation in live patients are dependent of the valvular configuration. Although trefoil balloons have the theoretical advantage to avoid complete obstruction of the aortic orifice during inflation, we observed that in presence of a tricuspid configuration, they could be potentially more occlusive than monofoil balloons since each of the 3 individual components of the trefoil balloon occupied the intercommissural spaces while inflated. However, they offered more residual free space when inflated in aortic valves with a bicuspid configuration (i.e. congenitally bicuspid valves or tricuspid valves with one fused commissure).In our opinion, these observations are relevant, since degenerative disease of the aortic valve (i.e. tricuspid valve without commissural fusion) is now recognized as the most common etiology of aortic stenosis in the elderly.Abbreviations AS aortic stenosis - AVA aortic valve area - PTAV percutaneous transluminal aortic balloon valvuloplasty A video supplement to this article has been published in Cardiac Imaging Video Journal volume 2, nr. 4, 1989, see Reference 29.     

Results of percutaneous valvuloplasty for calcific aortic stenosis with different balloon catheters

Percutaneous aortic valvuloplasty is a palliative treatment for patients with calcific aortic stenosis who would be poor candidates for surgical treatment. The results and associated complications of this procedure were analysed in a series of 47 patients in which different types of dilating catheters were used. In 25 patients a single balloon (19 mm) was used (group A), in 13 patients a bifoil balloon (2 x 15mm) (group B), and in the remaining nine patients (group C) a trefoil balloon (3 x 10mm) was used. An increase in aortic valve area was achieved in all patients. The results obtained with the bifoil balloon were better than with the other types of balloon catheter, with an increase in aortic area of + 118% vs. + 74% (monofoil) and + 76% (trefoil) (P less than 0.05). The tolerance of the inflation procedure was also better with this type of balloon, as it allowed for shorter inflation and deflation times. These results show that balloon aortic valvuloplasty, when indicated, is best performed with a bifoil balloon dilating catheter, and undue complications usually do not occur.     

Double Balloon Technique for Percutaneous Balloon Pulmonary Valvuloplasty: Comparison with Single Balloon Technique

This study was designed to document our results of double balloon pulmonary valvuloplasty and to evaluate if the double balloon technique is preferable to single balloon valvuloplasty in the relief of isolated valvar pulmonic stenosis. Double balloon valvuloplasty in twelve patients reduced the pulmonary valvar gradient from 100.5 ± 28.0 (mean ± SD) to 26.6 ± 12.5 mm Hg (P < 0.001) which remained improved, 17.5 ± 10.2 mm Hg (P < 0.001) at 6 to 14 month follow-up. Single balloon valvuloplasty with equivalent balloon/pulmonary valve annulus ratios (1.19 ± 0.14 vs 1.19 ± 0.15, P > 0.1) in another 12 patients also reduced (P < 0.001) the gradient from 96.3 ± 40.1 to 28.3 ± 17.3 mm Hg immediately following the procedure which at 6 to 13 month follow-up was 12.8 ± 9.9 mm Hg. The right ventricular peak systolic pressures (116.6 ± 24.5 vs 113.8 ± 41.5 mm Hg) and pulmonary valvar gradients (100.5 ± 28.0 vs 96.3 ± 40.1 mm Hg) prior to valvuloplasty, residual right ventricular pressures (47.4 ± 12.2 vs 54.3 ± 14.2 mm Hg) and pulmonary valve gradients (26.6 ± 12.5 vs 28.3 ± 17.3 mm Hg) immediately after valvuloplasty, and residual right ventricular pressures (43.1 ± 10.9 vs 41.1 + 12.5 mm Hg) and pulmonary valvar gradients (17.5 ± 10.2 vs 12.8 ± 9.9 mm Hg) on follow-up were similar (P ± 0.1) in both groups.
These data indicate that results of double balloon valvuloplasty are excellent but not superior to single balloon valvuloplasty. It is suggested that the double balloon valvuloplasty should be used if the pulmonary valve annulus is too large to dilate with a single balloon. There is no need for double balloon valvuloplasty if the pulmonary valve can be dilated with a commercially available single balloon.     

Assessment of the "long sheath" technique for percutaneous aortic balloon valvuloplasty

A 100 cm-long 16.5 F valvuloplasty catheter introducer was assessed as an adjunct for percutaneous transluminal aortic valvuloplasty (PTAV) via the femoral artery in 31 patients with severe aortic stenosis. Observed improvements in peak systolic gradient (81.6 +/- 29.9 mm Hg vs. 35.5 +/- 16.0 mm Hg, P less than 0.000001) and aortic valve area (0.6 +/- 0.4 cm2 vs. 1.0 +/- 0.6 cm2, P less than 0.00001) were similar to those achieved in a control group (C) of 17 patients in which no femoral sheath was used. However, a shorter procedure duration (211 +/- 81 min vs. 117 +/- 30 min, P less than 0.001) and a reduced rate of vascular complications at the femoral puncture site (41% vs. 6.5%) were observed in patients in whom the long sheath (LS) technique was used. The frequency of other PTAV-related complications was comparable (C = 35%, LS = 29%, P = n.s.). Other technical advantages of this device are: 1) prevention of looping and bending of the balloon catheter in tortuous vessels and easy positioning of the balloon across the aortic orifice provided by the LS trackability, 2) stabilisation of the balloon during inflation, 3) monitoring of supravalvular aortic pressure provided by the side-arm of the LS and reliable measurement of systolic gradient, and 4) the ability to perform aortograms without the need of another catheter in the ascending aorta. Thus, in our experience, the long sheath technique is a valuable adjunct for PTAV.     

Double vs single balloon technique for aortic balloon valvuloplasty

Percutaneous aortic valvuloplasty using a single dilating balloon has been associated with significant but modest reduction in transvalvular pressure gradient and increase in valve area. The balloon diameter is usually 20 mm or smaller to avoid disruption of aortic root structure and to permit forward blood flow during inflation. To evaluate the safety and efficacy of valvuloplasty using a combination of balloons with larger maximum inflated diameters, we compared results of aortic valvuloplasty in 21 patients using either the single or double balloon technique. Mean maximum inflated balloon diameter was 19.4 mm +/- 1.4 for the single balloon technique, while the mean sum of diameters for the simultaneous double balloon technique was 36.3 mm +/- 3.9. The mean age, aortic annulus diameter, and predilatation aortic valve area were not different among groups. Mean aortic transvalvular gradient reduction and mean aortic valve area increase were greater for the double balloon technique. The procedure was well tolerated with no major complications. No change in the degree of aortic regurgitation was noted. The double balloon technique for aortic valvuloplasty is safe and more effective at improving aortic valve area and transvalvular gradient than the conventional single balloon technique.     

Doppler echocardiographic observations during percutaneous aortic balloon valvuloplasty

To evaluate the hemodynamic changes occurring with percutaneous aortic balloon valvuloplasty for aortic stenosis, Doppler echocardiography was performed during the procedure in 16 patients. During balloon inflation, peak velocity and ejection time of the aortic valve systolic signals increased (26 and 30%, respectively; p less than 0.001). Aortic regurgitation deceleration time decreased from 1,337 to 625 ms (p less than 0.001). In three patients, aortic regurgitation stopped before end-diastole; in four patients, end-diastole forward flow across the aortic valve was documented. The deceleration time of the mitral valve inflow signal decreased from 303 to 194 ms (p less than 0.001) during balloon inflation, concurrently with an increase in left ventricular diastolic pressure. Mitral regurgitation signals became more prominent during inflation in 10 patients. Changes that occur during balloon inflation in the aortic valve include progressive left ventricular outflow obstruction, equalization of diastolic aortic and left ventricular pressures and changes in diastolic compliance.     

Balloon Aortic Valvuloplasty in the First Year of Life

Between February 1988 and September 1993 balloon aortic valvuloplasty was attempted in 33 consecutive patients in the first year of life: 20 patients (61%) were younger than J month. Major associated anomalies such as mitral stenosis, coarctation, and hypoplastic left ventricle were found in 11 cases (33%). The balloon dilation of the aortic valve was accomplished through the right carotid cut-down approach in neonates and patients with body weight < 5 kg, through a percutaneous femoral approach in the others; the procedure was completed in all. The peak systolic gradient across the aortic valve measured at catheterization fell from 80 ± 33 mmHg (range 25–165) before the dilation to 27 ± 17 mmHg (range 0–65), afterwards (P < 0.0001). The left ventricular ejection fraction increased from 44%± 26% to 61%± 17%, 24–48 hours after the procedure (P < 0.0001). Aortic insufficiency developed in 17 cases, being moderate in 2, mild in 6, and trivial in 9. Seven patients (21%), all in the first month of life, died within 30 days from the valvuloplasty; major associated anomalies were present in six; the death was due to a procedure related complication in one. No mortality was observed among the patients undergoing valvuloplasty beyond the first month of life. On follow-up (6 months to 6 years) aortic restenosis occurred in 3 cases; 1 was treated by surgical valvotomy, 2 by repeat balloon valvotomy; in another 2 cases, a subvalvular aortic obstruction developed and was relieved by surgical resection. There was no late mortality. Thus, balloon valvuloplasty appears to be an effective palliation for critical aortic stenosis in infancy. Early mortality is mainly related to associated anomalies.     

Percutaneous ventricular assist during aortic valvuloplasty: potential application to the deployment of aortic stent-valves

We evaluated the short-term safety and efficacy of using the TandemHeart(R) percutaneous ventricular assist device in high-risk patients undergoing aortic valvuloplasty procedures.Aortic valvuloplasty was performed in 4 patients who had no ventricular assist device support and in 7 patients who used the TandemHeart for hemodynamic support. The age range was 65 to 94 years (mean, 83 +/- 11 yr). The mean ejection fraction was 0.30 +/- 0.14. A transseptal antegrade approach to the aortic valve was used in 8 patients and a retrograde approach in the remaining 3.WITH THE TANDEMHEART, ALL PROCEDURES WERE TECHNICALLY SUCCESSFUL: each patient survived at least 1 month after the procedure. The mean total balloon inflation time was 37 +/- 10 sec. The aortic valve area was 0.6 +/- 0.1 cm(2) before the procedure and 0.9 +/- 0.2 cm(2) afterwards (P=0.006). Without TandemHeart support, 1 patient died of cardiac arrest during the procedure. The mean total balloon inflation time was 11 +/- 3 sec. Aortic valve area was 0.6 +/- 0 cm(2) before the procedure and 1.1 +/- 0.3 cm(2) afterwards (P=0.3). No patient developed aortic regurgitation.We conclude that use of the TandemHeart for hemodynamic support during high-risk aortic valvuloplasty is associated with favorable intraprocedural and short-term outcomes. With the TandemHeart in place, balloon placement was precise, and inflation was maintained for up to 45 sec without balloon displacement. These attributes are essential during stent-valve placement, are achieved without rapid ventricular pacing, and may reduce the risk of global ischemia and death.     

Changes in coronary blood flow and myocardial metabolism during aortic balloon valvuloplasty

The effects of balloon inflation on myocardial perfusion and metabolism were studied during aortic valvuloplasty in 17 patients with aortic stenosis, including 6 with associated coronary artery disease. Coronary sinus flow and blood samples were obtained before and during the first inflation, and 5 to 10 minutes after the last inflation. During inflation, coronary blood flow decreased (272 +/- 111 standard deviation to 166 +/- 92 ml/min; p less than 0.05), myocardial oxygen uptake fell and transcardiac lactate handling shifted from extraction to production (35 +/- 54 to -41 +/- 48 mumol/min; p less than 0.01). At the end of the procedure, aortic valve area had increased from 0.51 +/- 0.22 to 0.81 +/- 0.48 cm2 (p less than 0.002). Coronary sinus flow increased slightly above control values (+6%; difference not significant) and myocardial oxygen and lactate uptakes were back to control values. However, myocardial alanine production had increased from -3.6 to -6.6 mumol/min (p less than 0.05) and glutamine production was reduced or replaced by extraction (-3.3 +/- 2.1 to 3.5 +/- 3.8 mumol/min; p less than 0.05). Recovery of coronary flow, oxygen and lactate uptakes was not significantly different in patients with or without coronary artery disease, although the former patients tended to have less glutamine extraction and less improvement in their ejection fraction at the end of the procedure. Thus, aortic balloon valvuloplasty produces brief episodes of low-flow ischemia. Recovery of oxidative metabolism is almost immediate after deflation and no detrimental effect seems to persist at the end of the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral valve rupture during percutaneous dilation of aortic valve stenosis

A 62-year-old patient underwent catheter balloon valvuloplasty for aortic valve stenosis. During the procedure, iatrogenic severe mitral regurgitation was induced, requiring emergency surgery. At operation, extensive laceration of the septal mitral leaflet was found; chordae tendinae were intact. Retrospective examination of the cineangiogram revealed the presence of balloon indentation at the chordal level during inflation, which disappeared at full inflation. Mitral valve rupture was probably related to balloon entrapment in chordae tendinae, severe chordal stretching at inflation, and subsequent valve laceration. This severe complication or aortic valvuloplasty in adults has not been reported previously and probably could be avoided by careful observation of guidewire and balloon position before inflation.     

Percutaneous balloon aortic valvuloplasty: results in 23 patients

Percutaneous balloon aortic valvuloplasty (BAV) was performed in 23 consecutive patients with valvular aortic stenosis with no associated cardiac defects. The patients were 2 to 17 years old and were referred from 12 hospitals in 4 states. The balloon was positioned across the aortic valve and inflated to pressures of 80, 100, then 120 psi. Each inflation lasted 5 to 10 seconds. The arterial and venous catheters were connected together outside the groin to avoid excessive increase in left ventricular pressure during total aortic valve occlusion with the inflated balloon. Peak systolic aortic valve pressure gradient and cardiac output were measured before and 15 minutes after BAV. There was no significant change in cardiac output, but all patients had a lessened gradient. The gradient before BAV was 113 +/- 48 mm Hg, decreasing to 32 +/- 15 mm Hg after BAV (p less than 0.01). The left ventricular peak systolic pressure decreased from 221 +/- 54 to 149 +/- 21 mm Hg (p less than 0.01). No aortic regurgitation was noted in 13 patients and very mild aortic regurgitation was noted in 10 patients after BAV. The balloons were 10 to 20 mm in diameter, chosen at least 1 mm smaller than the diameter of the aortic valve anulus. Pressures of 100 to 120 psi were required to achieve full inflation of the balloons. Six patients had repeat cardiac catheterization studies 3 to 9 months after BAV. In none was there a significant change in peak systolic aortic valve pressure gradient or cardiac output compared with the study immediately after valvuloplasty.     

Use of a 3 French system for balloon aortic valvuloplasty in infants.

For infants with valvar aortic stenosis, balloon aortic valvuloplasty has supplanted surgical valvotomy as the initial treatment of choice at most institutions. Technological innovations have resulted in further miniaturization of balloon dilation catheters, allowing this procedure to be performed through smaller sheath sizes. Currently, the Tyshak-Mini balloon dilation catheter (B. Braun Medical) allows passage of up to an 8 mm dilation balloon catheter through a 3 Fr hemostatic sheath. The efficacy of this system for the treatment of valvar aortic stenosis in infants less than 6 months of age was evaluated in 20 patients undergoing 22 procedures. Mean age at the time of intervention was 26 +/- 46 days. Mean transvalvar gradient was 76 +/- 22 mm Hg prior to balloon dilation. Following balloon valvuloplasty, residual gradient was 26 +/- 12 mm Hg, reflecting a mean change in peak-to-peak gradient of 49 +/- 19 mm Hg. Postintervention increase in aortic insufficiency was one grade or less in 19/22 procedures, two grades in 2 procedures, and three grades in 1 procedure. There were no significant vascular complications reported immediately following the procedure. Repeat valvuloplasty was performed in three patients in which the 3 Fr system was used in two patients. The 3 Fr system for balloon aortic valvuloplasty in infants less than 6 months of age is effective and safe.     

Treatment of calcific aortic stenosis by balloon valvuloplasty

Recent reports have established the feasibility of using balloon valvuloplasty to reduce left ventricular outflow tract obstruction due to a calcified aortic valve. The present study summarizes experiences with this technique in 9 patients (7 women, 2 men, mean age 78 years) in whom balloon valvuloplasty was used to treat calcific aortic stenosis. Peak aortic valve gradient (mm Hg) decreased from 68 +/- 8 (mean +/- standard error of the mean) before valvuloplasty to 35 +/- 5 after valvuloplasty (p = 0.003). Mean aortic valve gradient decreased from 57 +/- 7 before valvuloplasty to 30 +/- 5 after valvuloplasty (p = 0.006). Calculated aortic valve area increased from 0.42 +/- 0.04 to 0.81 +/- 0.06 cm2 (p = 0.005). Balloon valvuloplasty failed to diminish aortic valve obstruction in only 1 patient who, at subsequent surgery, had a congenitally bicuspid aortic valve. Significant aortic regurgitation was not observed in any of the 9 patients after valvuloplasty. One patient did have a highly focal, presumably embolic, brain stem infarct during the procedure. Femoral arterial blood loss, related to wire-guided exchange of balloon catheters too large for a 12Fr introducer sheath, was minimized by direct arterial exposure in 8 of the 9 patients. Thus, these findings confirm the efficacy of balloon valvuloplasty for the treatment of calcific aortic stenosis. The procedure, however, is not without hazard.     

Congenital aortic stenosis: A novel technique for ventricular pacing during valvuloplasty

Objectives : The main objective of this study is to describe a new technique for rapid ventricular pacing to maintain balloon stability during balloon aortic valvuloplasty (BAV) without using transvenous temporary pacemaker electrode. Background : The safety and efficacy of rapid right ventricular pacing to facilitate balloon stability during BAV has been previously reported. However, it necessitates an additional femoral venous access, an additional sheath, and a temporary pacemaker electrode. Methods : This was a prospective pilot study. Rapid ventricular pacing was performed through back‐up guidewires inserted into the left ventricle for balloon advancement and by an adhesive patch placed on the back of the patient. The technique was performed during BAV procedure in all of 15 consecutive children diagnosed as congenital aortic stenosis. Pacing was performed at a rate decreasing systolic aortic pressure to the point of 40–50% of baseline. Results : The technique was successful in all patients. Effective capture, stable pacing, and balloon stability were achieved in all children using very low outputs. No sustained arrhythmias or other procedure‐related complications occurred. Mean aortic valve gradient decreased from 68.5 ± 20.4 mm Hg to 20.4 ± 10.2 mm Hg. Degree of aortic regurgitation progressed from grade 0 to 1 in three patients and remained unchanged in 12 patients. Conclusions : This study demonstrated that back‐up guidewires can be used effectively and safely for pacing during BAV procedures. This technique omits probable complications related to a second vascular access and may shorten the procedure time and decreases costs by eliminating the use of an additional sheath and a temporary pacemaker electrode. © 2008 Wiley‐Liss, Inc.     

经皮球囊扩张术治疗儿童先天性主动脉瓣狭窄

目的探讨儿童先天性主动脉瓣狭窄（aortic stenosis,AS）球囊扩张的治疗效果。方法选择21例单纯性AS患儿,其中1例合并动脉导管未闭（PDA）,3例因导管难以进入左室,2例左心导管测跨主动脉瓣压力阶差（AP）小于50mmHg（1mmHg=0．133kPa）而未扩张,其余16例采用与瓣环直径之比为0．98±0．04（0．92～1．10）的球囊扩张治疗,合并的PDA予Amplatzer伞片封堵治疗。结果即刻AP下降至原AP50％以上者13例,占81．25％;下降至原AP40％～50％者2例。随访6个月～5年,3例患儿AP回复至50mmHg以上,分别予第二次扩张或外科手术后好转。无一例轻度以上的主动脉瓣反流。结论AS经皮球囊扩张术结果表明,球囊扩张对单纯性AS具有一定疗效,由于其非开胸、方便且较安全地缓解左心室流出道梗阻,从而可替代或延缓外科开胸瓣膜切开术,为AS的治疗提供了另外一种选择。     

Intermediate-term effectiveness of balloon valvuloplasty for congenital aortic stenosis. A prospective follow-up study.

BACKGROUND. Percutaneous balloon valvuloplasty has proven to be acutely effective in the treatment of congenital valvar aortic stenosis; however, the intermediate- and long-term effectiveness of the procedure remain to be documented. METHODS AND RESULTS. To assess the intermediate-term effectiveness of balloon valvuloplasty, repeat catheterization was performed in 27 of 30 children 1.7 +/- 0.1 years after balloon valvuloplasty for congenital aortic stenosis (AS). In 33 children the peak AS gradient was reduced acutely by 55% from 77 +/- 4 to 35 +/- 3 mm Hg (p less than 0.001), and left ventricular systolic pressure was reduced from 176 +/- 4 to 138 +/- 4 mm Hg (p less than 0.001). Despite a technically adequate valvuloplasty procedure, three patients had inadequate relief of obstruction and required complex surgical intervention. Twenty-seven of the 30 patients available for late reevaluation (90%) enrolled in the follow-up study. The peak AS gradient remained significantly reduced compared with that present before valvuloplasty (29 +/- 3 versus 77 +/- 4 mm Hg, p less than 0.001). Furthermore, there was no difference in peak AS gradient at follow-up compared with that immediately after valvuloplasty. The greatest increase in gradient at reevaluation was 14 mm Hg. Twenty of 27 patients (74%) had no change in the degree of aortic insufficiency at follow-up compared with that present before valvuloplasty. At follow-up, 16 patients had no aortic insufficiency at all, and only two had moderate-to-severe (3-4+) insufficiency. Femoral artery injury was documented in four patients, three of whom were under 12 months of age at valvuloplasty. CONCLUSIONS. Balloon aortic valvuloplasty provides safe and effective intermediate-term gradient relief without early restenosis in children and adolescents with congenital AS.     

Drug Delivery at the Aortic Valve Tissues of Healthy Domestic Pigs with a Paclitaxel-Eluting Valvuloplasty Balloon

Background: Restenosis occurs invariably within 1 year following balloon valvulopasty in aortic valve stenosis. The mechanism of restenosis seems to involve a dynamic cellular component that could be a target for drug inhibition. We investigated the feasibility of local drug delivery at the aortic valve tissues of healthy pigs with a paclitaxel-eluting balloon.
Methods: Aortic valvuloplasty was performed in eight anesthetized domestic pigs using paclitaxel-eluting balloons (3 μg/mm² balloon surface area). They were assigned to two or four times 15-second balloon inflations and were sacrificed 30 minutes after final balloon inflation.
Results: The aortic annulus to balloon diameter ratio was 1.15 ± 0.07. The mean paclitaxel concentration in the aortic valve leaflets was 0.91 ± 1.36 μg/mL (0.34 ± 0.05 μg/mL in the two-inflation group, 1.48 ± 1.86 μg/mL in the four-inflation group, P = 0.23). The percentage of the total paclitaxel dose recovered in the aortic valve leaflets was 18 ± 11⁻⁶% (13 ± 6⁻⁶% and 25 ± 14⁻⁶% in the two- and four-inflation group, P = 0.16).
Conclusion: Local drug delivery at the aortic valve leaflets of healthy pigs with a paclitaxel-eluting balloon is feasible and concentrations within the therapeutic window are detected 30 minutes after the procedure. The antirestenotic potential of this treatment should be studied.     

Percutaneous balloon valvuloplasty for congenital aortic valve stenosis]

We performed percutaneous balloon aortic valvuloplasty for 10 patients with congenital aortic valve stenosis aged from 2 to 17 years and a 54-day-old infant with critical stenosis. The retrograde single balloon technique was used for 6 patients including the infant; the retrograde double balloon technique was used for 3 patients; and both techniques for 2 patients. The valvuloplasty was effective for 10 patients except for the infant in terms of the peak systolic pressure gradient between the left ventricle and aorta (from 80.6 +/- 21.9 to 29.4 +/- 17.0 mmHg). Follow-up cardiac catheterizations one year after valvuloplasty in 3 patients and 3 years after valvuloplasty in one patient disclosed no re-stenosis. Aortic regurgitation newly developed in one patient and advanced Sellers' classification I in 3 patients, however, all of them were asymptomatic and did not progress further. In the infant with critical stenosis, sufficient dilatation could not be achieved and acute myocardial infarction mainly at the lateral wall of the left ventricle developed during the valvuloplasty. He died 3 days after the valvuloplasty. The double balloon technique was found to be superior to the single balloon technique with the latter being ineffective in 2 cases, because the fixation of the balloon at the annulus was very difficult. Double balloon technique has low risk of vascular trauma and is applicable to a large sized annulus, because it enables blood supply between the 2 balloons during the inflation period.     

Aortic percutaneous transluminal valvuloplasty in elderly patients by balloon larger than aortic anulus

Twenty-four elderly patients (79 +/- 7 years) with long-standing calcified aortic stenosis have been divided in two comparable groups of 12. The first group was treated with 19 mm balloon percutaneous transluminal valvuloplasty, where the balloon diameter was always smaller than the aortic anulus diameter. Peak-to-peak aortic valve gradient decreased from 76 +/- 32 mmHg to 30 +/- 19 (P less than .05), and the aortic valve area, calculated by Gorlin formula, increased from 0.40 +/- 0.17 cm2 to 0.57 +/- 0.17 (P less than .05). The second group was treated with a trefoil 25 mm balloon, always larger than the aortic anulus diameter. In this second group, peak-to-peak aortic valve gradient decreased from 73 +/- 34 mmHg to 23 +/- 15 (P less than .05), and aortic valve area increased from 0.47 +/- 0.14 cm2 to 0.88 +/- 0.36 (P less than .05), increasing thus more than in group I (P less than .05). Clinical tolerance to balloon inflation was not the same according to individual patients but was similar between the two groups; complications were comparable in the two groups. These results suggest that aortic valvuloplasty by trefoil balloon larger than aortic anulus can provide wider aortic valve area without increasing complication rate.