Paulo A. Ribeiro

Mechanism of mitral valve area increase by in vitro single and double balloon mitral valvotomy

The mechanism of mitral valve area increase by double balloon mitral valvotomy in vitro has not been defined, nor have the mitral valve area results achieved by single versus double balloon mitral valvotomy technique been compared. After a selection of 29 intact mitral valves excised at cardiac surgery from patients with a mitral valve area less than or equal to 1.5 cm2 was made, double balloon mitral valvotomy was attempted in 14 valves using two 20-mm diameter balloon catheters (group 1) and single balloon mitral valvotomy using a 20-mm balloon was undertaken in 15 valves (group 2). In group 1 the mitral valve area increased from 0.9 +/- 0.03 to 1.9 +/- 0.05 cm2 (mean +/- standard error of the mean) (p less than 0.001), with a mean anterior commissural split of 5.3 +/- 0.2 mm and a posterior split of 4.1 +/- 0.2 mm. Following single balloon valvotomy (group 2), the mean mitral valve area increased from 0.8 +/- 0.03 to 1.2 +/- 0.03 cm2 (p less than 0.001), with the mean anterior commissural split being 2.6 +/- 0.2 mm and the posterior 2.1 +/- 0.2 mm. Ten mitral valves from group 2 underwent a second dilatation using the double balloon technique and the mitral valve area increased further from 1.2 +/- 0.06 to 1.9 +/- 0.06 cm2 (p less than 0.001). Overall, commissural splitting occurred preferentially in calcified commissures (81%), as opposed to only 56% of noncalcified commissures. Commissural splitting is the manner in which mitral valve area increases after double balloon mitral valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

One-year follow-up after percutaneous double balloon mitral valvotomy.

Abstract To determine the long-term results after double balloon mitral valvotomy and the incidence of restenosis, 41 consecutive patients were restudied 1 year after successful balloon mitral valvotomy for severe symptomatic rheumatic mitral stenosis. There were 27 female and 14 male patients, mean age 26 ± 9 years.

Balloon valvotomy for pregnant patients with severe pliable mitral stenosis using the Inoue technique with total abdominal and pelvic shielding

Balloon valvotomy by means of the Inoue technique was attempted in seven pregnant (5 to 9 months) patients with severe mitral stenosis; the mean age of the patients was 32 +/- 8 years, and all had a two-dimensional echocardiographic mitral valve score of < 8. Indications for Inoue balloon valvotomy included severe symptomatic mitral stenosis with a Doppler mitral valve area < or = 1 cm2 and heart failure refractory to medical therapy, or absolute contraindications for the use of beta-blockade; Inoue valvotomy was also indicated for patients who lived a long distance from the hospital. Inoue balloon valvotomy was performed with no angiography and total pelvic and abdominal shielding; the balloon catheter was introduced into the right atrium without the aid of fluoroscopy, which was used for the transseptal puncture. Stepwise two-dimensional echocardiographic Doppler mitral valve dilatation was done. After Inoue balloon valvotomy the mean Doppler mitral valve area increased from 0.8 +/- 0.1 to 2.0 +/- 0.3 cm2 (p < 0.01) and by two-dimensional echocardiography from 0.8 +/- 0.2 to 1.9 +/- 0.3 cm2 (p < 0.01), with no significant Doppler residual stenosis (defined as mitral valve area < or = 1.5 cm2). The mean total fluoroscopy time was 16 +/- 7 minutes. The degree of mitral regurgitation increased in two patients from grade 1+/4+ to grade 2+/4+ and from grade 0+/4+ to grade 2+/4+, respectively. There was no mortality or significant morbidity. Pregnancy was uneventful in all patients, and all were delivered of normal babies without complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of mitral valve area results of balloon mitral valvotomy using the inoue and double balloon techniques

Abstract Inoue pioneered the mitral balloon valvotomy technique using his homemade balloon catheter as a nonsurgical therapeutic alternative to the surgical treatment of mitral stenosis. 1 Because Inoues balloon catheter was not commercially available at the time, Zaibag et al 2 developed the principal of the double balloon technique. 12 The double balloon technique has prevailed to date since the mitral valve areas achieved are excellent and are maintained at long-term follow-up. 2–4 Although the mechanism of mitral valve dilatation for both the Inoue and the double balloon technique are similar, 1–5 i.e., commissural splitting, no comparative clinical data have been reported. Previous published series include noncomparable groups of patients, with different ages and particularly different mitral valve and subvalvular anatomy. 1–4 We selected a homogenous, young population of patients with severe rheumatic mitral stenosis; both groups of patients had comparable mitral valve and subvalvular anatomy and age. The objective of the study was to compare the mitral valve areas and the total procedure times achieved, using the 2 different techniques.

Percutaneous mitral valvotomy with the Inoue balloon catheter in children and adults: immediate results and early follow-up.

Percutaneous mitral balloon valvotomy (PMV) using the Inoue balloon catheter was attempted in 60 consecutive patients with severe symptomatic mitral stenosis. There were 10 children (mean age 13 years) and 50 adults (mean age 31 years). Forty patients were females and 20 were males; 53 were in sinus rhythm. The procedure was technically successfully performed in 57 (95%) patients. There were no deaths or thromboembolic complications. Balloon valvotomy was done using a 22 to 30 mm diameter catheter with the echo/Doppler guided stepwise mitral dilatation technique. After PMV the mean left atrial pressure decreased from 23.0 +/- 5.0 to 14.0 +/- 4.0 mm Hg (p less than 0.001). The mean mitral valve gradient (MVG) decreased from 15.0 +/- 4.0 to 6.0 +/- 2.0 mm Hg (p less than 0.001). The mitral valve area (Gorlin formula) increased from 0.7 +/- 0.2 to 1.6 +/- 0.4 cm2 (p less than 0.001). The mitral valve area as determined by echocardiography increased from 0.8 +/- 0.1 to 1.9 +/- 0.3 cm2 (p less than 0.001). Mild mitral regurgitation (MR) developed in six patients (11%) and increased by one grade in another five patients (9%). No patient developed severe mitral regurgitation. Mitral valve area at mean follow-up of 4.8 months remained unchanged at 1.9 +/- 0.3 cm2. We conclude that PMV, using the Inoue balloon catheter, is safe and effective in the treatment of severe mitral stenosis in children and adults, without inducing significant mitral regurgitation.

Percutaneous double balloon pulmonary valvotomy in adults: One- to two-year follow-up

Abstract Percutaneous balloon catheter dilatation of the pulmonary valve has become a widely accepted therapeutic alternative to surgical valvotomy: immediate and shortterm clinical and hemodynamic improvements have been documented. 1–4 This study evaluates 1- to 2-year followup results in the first consecutive series of adult patients with congenital pulmonary valve stenosis (PS) to undergo percutaneous double balloon pulmonary valvotomy.

A new expandable intracoronary tantalum (Strecker) stent: early experimental results and follow-up to twelve months.

A new radiopaque balloon expandable tantalum stent was tested in the coronary arteries of sheep. A total of 28 stents with a diameter of 2.0 to 3.8 mm were successfully deployed. The stent to coronary artery diameter ratio was 1.1-1.2:1. The animals were heparinized with 100 U/kg of heparin but did not receive antiplatelet drugs. Coronary angiography that was performed 10 minutes after stent implantation showed 100% patency with no side-branch occlusion. Four sheep died within 2 hours of stent implantation, and pathologic studies showed thrombosis of the smaller sized stents: 2 mm (n = 2), 2.8 mm (n = 1), and 3.2 mm (n = 1); three fourths of the sheep had two stents implanted. An oversized stent caused coronary rupture and cardiac tamponade in one other sheep. Follow-up study protocol included coronary angiography before animal sacrifice and pathologic studies within 48 hours (n = 11), 2 weeks (n = 1), 3 months (n = 2), 5 months (n = 1), 10 months (n = 7), and 12 months (n = 1). At 3 to 12 months of follow-up the coronary stent was completely covered with a layer of neointima, and there was no angiographic evidence of coronary stenosis and patent side branches. According to histologic examination, the neointima had nonuniform thickness (20 to 330 microns) and consisted of smooth muscle cells and some collagen. At 7 months of follow-up one of seven stents had angiographic (20%) and pathologic evidence of stenosis, which was secondary to thrombus. The tantalum device is easily deployed technically and notable for its excellent fluoroscopic visibility and flexibility. Thrombosis with a tantalum stent remains a problem, and therefore the larger diameter stents > or = 3.2 mm, antiplatelet drugs, and anticoagulation therapy are indicated for human studies. Implantation of multiple coronary stents increases the risk of stent thrombosis. The long-term, mild neointimal thickness and the patency of the stent and side branches are encouraging.

Percutaneous double balloon valvotomy for rheumatic tricuspid stenosis

Abstract We attempted. tricuspid balloon valvotomy in 4 selected consecutive symptomatic patients (2 male and 2 female) (mean age 41 years), with severe tricuspid stenosis (TS) and mild mitral valve disease. The immediate and short-term results are reported. To define the ph

Comparison of results of percutaneous balloon mitral valvotomy using single and double balloon techniques

siologic effects of balloon tricuspid valvdtomy, we studied the cardiac output of these patients at rest and during treadmill exercise, both before and after the procedure.

Provocation and amplification of the transvalvular pressure gradient in rheumatic tricuspid stenosis.

Abstract This study compares the mitral valve area results achieved in balloon mitral valvotomy, using either a single 20-mm diameter balloon catheter, or a combination of 2 balloon catheters 18 + 20 or 20 + 20 mm in diameter.