Comparison between single (Inoue) and double balloon mitral valvuloplasty: Immediate and short-term results

This study compared the results in 60 consecutive patients with severe rheumatic mitral stenosis, who underwent percutaneous double-balloon mitral valvuloplasty by means of a combination of 20 mm + 20 mm diameter balloon catheters (group A), with a similar group of 60 consecutive patients who underwent single (moue) balloon mitral valvuloplasty (group 6). After balloon mitral valvuloplasty the hemodynamic measurements showed significant improvement in both groups: in groups A and 6, respectively, mitral valve area calculated with the Gorlin formula increased from 0.9 t 0.2 to 2.1 t 0.5 cm2 (p < 0.001) and from 0.6 k 0.2 to 1.9 f 0.4 cm2 (p < 0.001). There was a significant improvement in cardiac functional status in both groups. There was no significant difference between the groups with regard to clinical or hemodynamic improvement, technical failure rate, inadequacy of dilatation, or complications. However, the double-balloon technique was more complex and involved a longer screening time-group A, 40 ? 12 minutes; group 8, 21 i- 10 minutes (p < 0.001). In our institution the disposable supplies used for the lnoue balloon technique were 40% more expensive than those used for the double-balloon technique. (AM HEART J 1992;123:1561.)

Moheeb Abdullah, MRCP, Murtada Halim, MRCP,

Vijayaraghavan Rajendran, MRCP, William Sawyer, MD, and

Muayed al Zaibag, FRCP. Riyadh, Saudi Arabia

The first successful percutaneous balloon mitral val- vuloplasty was reported by Inoue et a1.l in 1984; these investigators used a single-balloon catheter designed for mitral valvuloplasty (Inoue balloon). A single balloon designed for peripheral arterial angioplasty had been used in the United States for mitral dilata- tion.2 Because the results were less than ideal (mitral valve area = 1.0 to 1.5 cm2) and the Inoue balloon was not commercially available, the single-balloon tech- nique was soon replaced by the so-called “double- balloon technique,” in which two balloon catheters (Mansfield Scientific, Mansfield, Mass.) were used. This institution began to use the double-balloon technique in 198L3 The procedure has subsequently become very well established as an alternative to the surgical treatment of severe rheumatic mitral steno- sis.“-s Between January 1990 and May 1991, the Inoue single-balloon technique of mitral valvulo- plasty also was used in 60 consecutive patients with severe rheumatic mitral stenosis (group B). The re-

From the Riyadh Cardiac Center, Armed Forces Hospital.

Received for publication Aug. 26, 1991; accepted Dec. 2, 1991.

Reprint requests: Dr. Moheeb Abdullah, Department of Adult Cardiology, Riyadh Armed Forces Hospital, PO Box 7897, Riyadh 11159, Saudi Arabia.

4/l/36248

sults in this group of patients were compared with those in the first 60 consecutive patients with severe rheumatic mitral stenosis who had undergone dou- ble-balloon mitral valvuloplasty with a combination of 20 mm + 20 mm diameter balloon catheters (group A). The parameters compared were clinical improve- ment, mitral valve area achieved, technical failure, inadequacy of dilatation, complication rate, and ease of the procedure.

METHODS

Between February 1987 and January 1989, a total of 60 consecutive patients with symptomatic severe rheumatic mitral stenosis underwent double-balloon mitral valvulo- plasty with a combination of 20 mm + 20 mm diameter balloon catheters (group A). This combination of balloon catheter sizes was demonstrated by Zaibag et al9 to achieve the best result. Patient characteristics are shown in Table I. Atria1 fibrillation was present in nine patients (15 % ). All of these patients, as well as the majority of the patients in sinus rhythm, received anticoagulation therapy (warfarin) for 8 weeks before the procedure. Nine patients (15 % ) had undergone previous surgical mitral valvuloplasty. Forty- seven patients (78%) had no angiographic mitral regurgi- tation (MR), 12 patients (20%) had MR grade l/4, and one patient had MR grade 214. No patient had MR grade 314 or 414 (Grossman scale 0 to 4).

1581

1582 Abdullah et al. June 1992

American Heart Journal

Table I. Patient baseline characteristics Table II. Guidelines for selection of Inoue balloon size

Characteristics Group A Group B

Age range (yr) Mean (yr) Sex

Male Female Ratio

NYHA class II III IV

Mean BSA (m2) Degree of angiographic MR

No MR Grade l/4 grade 2/4

Fluoroscopic evidence of calcification (leaflet, commissures, or both)

Other valve lesions (mild to moderate degree)

16-17 14-63 33 k 10 34 + 12

32 17 28 43

l.l:l 0.4:1

29 (48 % ) 30 (50%)

1 (2%) 1.6 _t 0.2

47 (78%) 12 (20%)

13 (22%)

35 (58%)

23 (38%) 34 (54%)

3 (5%) 1.6 k 0.2

38 (63%) 22 (37%)

-

10 (17%)

44 (73%)

MI?, Mitral regurgitation; LISA, body surface area; NYHA, New York Heart Association.

Procedure. Each patient signed an informed consent form for the procedure. All of the operators performing the procedures in group A were experienced and competent in the particular double-balloon mitral valvuloplasty tech- nique used, which has been described previously.3 The Inoue technique has also been described in detail15; a step- wise mitral valve dilatation technique was used. Pulmo- nary angiography with levophase was performed before transseptal puncture to delineate the left atrium. Heparin, 150 units/kg, was given immediately after the transseptal puncture.

Between January 1990 and May 1991, a total of 60 con- In both groups A and B, hemodynamic data were secutive patients underwent Inoue single-balloon mitral obtained from all patients before the balloon mitral valvu- valvuloplasty for symptomatic severe rheumatic mitral loplasty and at the conclusion of the procedure. These in- stenosis (group B) (Table I). The size of the balloons used cluded transmitral valve diastolic gradient calculated by was determined according to patient body surface area and means of direct left atrium/left ventricle (LA/LV) pres- height as shown in Table II. The maximum balloon diam- sures (except for one patient in group B with a St. Jude eter used at full inflation ranged from 24 to 31 mm; 26 mm aortic valve prosthesis) and cardiac output determined by and 28 mm were the sizes most commonly used. Atria1 fi- means of the thermodilution method. The mitral valve area brillation was present in six patients (10 % ); these patients was calculated by means of the Gorlin formula. An oxygen together with 22 patients (37 % ) in sinus rhythm received saturation run was obtained after balloon mitral dilatation warfarin for 8 weeks before the procedure. The six patients to assess the presence of left-to-right shunt through any with atria1 fibrillation underwent transesophageal echocar- iatrogenic atria1 septal defect. Left ventricular angiography diography in the 24 hours preceding the procedure. Ten was performed in all patients before and after the proce- patients (17%) had undergone previous surgical mitral dure to assess the presence and degree of MR. Patients in valvotomy. Thirty-eight patients (63%) had no angio- group B had echo-Doppler studies after each inflation to graphic MR and 22 (37%) had MR grade 114. No patient assess mitral valve area, commissural split, and degree of in group B had MR that was more than grade l/4. There MR. Similar studies were performed in group A if the op- was no significant difference between the two groups with erator thought they were required. The echocardiography regard to the degree of MR before balloon mitral valvulo- machines used were Toshiba Sonolayer models SSH65A plasty. and SSHlGOA (Toshiba Corporation, Tokyo, Japan).

Comprehensive two-dimensional echocardiography with spectral and color Doppler imaging was performed in all patients in both groups before balloon mitral valvuloplasty, to ascertain the presence of severe rheumatic mitral steno- sis, to determine the degree of MR and the morphology of the mitral valve, to exclude left atria1 thrombus, and to de- termine the presence and degree of other associated valve lesions. The exclusion criteria in both groups for balloon valvuloplasty were: left atria1 thrombus, MR more than grade 214, and other associated valve lesions necessitating surgery in their own right. The baseline characteristics of age, weight, body surface area, functional class, calcifica-

Two-dimensional echocardiography with spectral and color Doppler imaging was performed in all patients within 24 hours of the procedure and at 24-hour and 6-week fol- low-up studies. The mitral valve area was determined by Doppler imaging according to the pressure half-time method described by Hatle et al.1° The degree of commis- sural split following the procedure was determined. The images were recorded on magnetic tape for future inde- pendent analysis.

The symptomatic status of the patients-New York Heart Association (NYHA) functional class-was com- pared in both groups at 6-week follow-up studies.

Diameter Surface (extra) area

Size (mm) fm9

L 26-30 (31) > = 1.9 M 24-28 (29) > = 1.6 S 22-26 (27) > = 1.3

ss 20-24 (25) <1.3

L, Large; h’, medium; S, small: SS. very small.

Height (cm)

>180 >160 >147 = <147

tion of the mitral valve, previous mitral valvuloplasty, and severity of mitral stenosis were similar in both groups, al- though there were more males in group A (p < 0.01).

Volume 123

Number 6 Inoue versus double-balloon mitral valvuloplasty 1583

lM.Q#1 p~0.001

LA Dtwmm?

El Post valvuloplasty

Fig. 1. Comparison of mean mitral valve diastolic gradient (Gradient) and left atrial pressure (LA pres- sure) before and after percutaneous balloon mitral valvuloplasty between group A and group B.

t&VA oma 2.5

1 P~O.001 P*Q.QQ? P~Q.001

21 T 1.*0.3 T r.*ow 1.893.4

Group A Group 3 Group A Group 3

RPPLER CIi”THETER n PI‘S vatvutq‘3fmy I Post valv~loplasty

Fig. 2. Comparison of mitral valve area (MVA) measured by Doppler pressure half-time (Doppler) and Gorlin formula (Catheter) before and after percutaneous balloon mitral valvuloplasty between group A and group B.

Statistical analysis. Continuous variables are expressed as mean + standard deviation. Paired and unpaired t tests, together with chi-square or Fisher’s exact tests where ap- propriate, were used to analyze differences within and be- tween the groups.

RESULTS

Hemodynamics. The measured hemodynamic pa- rameters showed significant improvement in both groups immediately after balloon valvuloplasty (Figs. 1, 2, and 3 and Table III). There was no significant

statistical difference in the final result achieved be- tween group A and group B with regard to mitral valve area, mitral valve diastolic gradient, pulmonary artery systolic pressure, left atria1 pressure, and car- diac index.

Technical failure. Technical failure-defined as the inability to advance the balloon across the mitral valve for various reasons-occurred in three patients (5 5%) in group A and two (3%) in group B. In group A one patient had cardiac tamponade after transsep- tal puncture before the insertion of the balloon. This

1584 Abdullah et al. June 1992

American Heart Journal

Fig. 3. Comparison of cardiac index before and after percutaneous balloon mitral valvuloplasty between group A and group B.

Table III. Comparison of hemodynamic results before and after balloon mitral valvuloplasty in groups A and B

Hemodynamics

Group A Group B

Before After Before After dilatation dilatation dilatation dilatation

Mean left atria1 pressure (mm Hg) Mean mitral valve diastolic

gradient (mm Hg) Mean mitral valve area (cm2) Cardiac index (L/min/cm2) Pulmonary artery mean systolic

pressure (mm Hg)

22 f 4 12 jr 5* 20 + 6 11 -t 3* 14 f 4.5 4.5 + 2.3* 12.4 + 4.8 3.5 t 1.7*

0.9 + 0.5 2.1 i 0.5* 0.8 +- 0.2 1.9 I 0.4* 2.3 + 0.5 2.8 i. 0.5* 2.2 * 0.5 2.4 + 0.5* 46 k 16 39 k 6* 43 f 20 40 i- 17t

*p < 0.001. tp < 0.01.

patient underwent emergency surgery during which a hemorrhagic pericardial effusion was seen. Open mitral valvuloplasty was performed with no compli- cations. In the other two patients, crossing the mitral valve with two balloons proved impossible. Both un- derwent open mitral valvuloplasty a few weeks later. In group B one patient had tamponade after trans- septal puncture. Pericardiocentesis was performed in the cardiac catheter laboratory; after stabilization he underwent mitral valve replacement. In the other patient in group B, it was difficult to cross the atria1 septum with the balloon, and she underwent open mitral valvuloplasty a few weeks later.

Inadequate dilatation. Inadequate dilatation-de- fined as a final mitral valve area of less than 1.5 cm2-occurred in two patients (3 % ) in each group. Of the two patients in group A, one had undergone pre-

vious mitral valvuloplasty in 1976; he had moderate calcification of the mitral valve. During the balloon mitral valvuloplasty there was imperfect alignment of both balloons across the mitral valve. The mitral valve area increased from 0.5 to 1.2 cm2 with mild MR. The patient improved symptomatically after balloon mitral valvuloplasty and was subsequently managed with medical therapy. The other patient had moderate calcification of the mitral valve, and the maximum mitral valve area achieved was 1.2 cm2. Because he continued to be symptomatic, open mitral valvuloplasty was performed.

Of the two patients in group B, one with severe mitral stenosis (mitral valve area = 0.5 cm2) under- went stepwise dilatation with balloon diameters of 22, 24, and 26 mm, respectively; he had mild MR af- ter the first dilatation and subsequently had moder-

Volume 123

Number 6

NYHA 0 Pre-PTBMV

I -

II -

III -

IV -

Inoue versus double-balloon mitral valvuloplusty 1585

0 Post-PTBMV

GROUP A GROUP B

Fig. 4. Comparison of New York Heart Association (NYHA) functional class before and after percutane- ous transvenous balloon mitral valvuloplasty (PTBMV) between group A and group B (patients who un- derwent cardiac surgery were excluded).

ate MR (grade 2 to 3/4) with a final mitral valve area of 1.1 cm2. The degree of MR that developed caused the procedure to be abandoned at that stage; the pa- tient underwent mitral valve replacement a few weeks later. The second patient had undergone pre- vious mitral valvuloplasty and aortic valve replace- ment with a St. Jude valve in 1986. Despite use of the maximum balloon inflation size (31 mm diameter), the maximum valve area achieved was 1.1 cm2 with no MR. The patient then underwent the double-bal- loon technique with a combination of 20 mm + 20 mm balloon catheters; however, despite good align- ment of both balloons across the valve, the valve area remained the same. He was then referred for cardiac surgery, and during the surgical procedure the mitral valve was found to be severely thickened, deformed, and fibrosed, and it was replaced with a St. Jude me- chanical valve.

Two-dimensional echocardiographic and Doppler studies. These studies were performed in both groups on the day after balloon mitral valvuloplasty. The mitral valve area measured by Doppler imaging guided by color flow mapping increased from 0.9 f 0.2 to 1.9 -+ 0.3 cm2 (p < 0.001) in group A and from 0.9 ? 2 to 1.9 f 0.3 cm2 (p < 0.001) in group B. Both commissures were judged to be split adequately in 50 of 58 patients (86 % ) in group A and 54 of 59 patients (91% ) in group B.

All of the patients who underwent mitral balloon valvuloplasty were reassessed 6 weeks after the pro- cedure, and two-dimensional echocardiographic and Doppler studies were performed at that time. The mitral valve area (1.9 + 0.2 cm2) and degree of MR remained the same in both groups.

Complications. There were no procedure-related

Table IV. Comparison of mitral regurgitation after percu- taneous balloon mitral valvuloplasty between groups A and B

Degree of MR Group A Group B p Value

No change 34 (60%) 36(62%) >0.5 One grade down 1(2%) 3 (5%) >0.5 One grade up 12 (21%) 14(24%) >0.5 Two grades up 5(9%) 3(5%) >0.5 Three grades up 2 (3%) 2 (3%) >0.5 Four grades up 3(5%) 0 >0.5

MR. Mitral regurgitation.

deaths in either group. No thromboembolic compli- cations, loss of consciousness, or significant bleeding occurred in either group.

Tumponade. One patient in each group had car- diac tamponade related to transseptal puncture. Both patients were stabilized and underwent open mitral valvulop!asty.

Mitral regurgitation. Only five patients (8%) in group A and two patients (3 % ) in group B had mod- erately severe to severe MR (grade 3 to 4/4) (Table IV). Only one patient in group A required emergency mitral valve replacement for severe MR, inasmuch as he was hemodynamically unstable. The remaining four patients in group A and the two patients in group B were treated medically because they were not very symptomatic. Predilatation severity of mitral steno- sis, degree of MR, calcification of the mitral valve, and patient age and sex were not found to be predic- tors of any postdilatation increase in MR.

Atria1 septal defect. No patient in either group had

1588 Abdullah et al. June 1992

American Heart Journal

significant left-to-right (L:R) shunt-defined as L:R >1.4:1-after the procedure.

Other complications. One patient in group A had a femoral arteriovenous fistula.

Screening time. The mean screening time for diag- nostic cardiac catheterization and balloon mitral valvuloplasty was 40 k 12 minutes in group A and 21 f 10 minutes in group B (p < 0.001).

Cost. The charges for the disposable supplies used for balloon valvuloplasty in our hospital in groups A and B were 1870 and 2600 United States dollars, re- spectively.

Clinical improvement. At the 6-week follow-up studies there was significant clinical improvement in both groups. All patients in group A were in NYHA functional class I or II compared to 45% before the procedure (p < 0.001). All patients in group B were in NYHA functional class I or II compared to 38% be- fore the procedure (p < 0.001) (Fig. 4).

DISCUSSION

Percutaneous transvenous balloon mitral valvulo- plasty for symptomatic severe rheumatic mitral stenosis has achieved good results in many centers, proving the effectiveness and safety of the proce- dure.]+? The two techniques used principally are the Inoue procedure, which uses a specially designed single balloon, and the double-balloon technique. This study compared the results in 60 consecutive patients who underwent double-balloon mitral val- vuloplasty with a combination of 20 mm + 20 mm balloons with findings in the first 60 consecutive pa- tients who underwent the Inoue single-balloon tech- nique. Although this study was not randomized, both groups had symptomatic severe mitral stenosis with similar baseline characteristics apart from sex distri- bution.

Previously published comparisons between these two methods of balloon mitral valvuloplasty usually have been in disparate groups of patients.i’ The populations in these two groups had many of the same characteristics: both were relatively young and had pliable valves, although 13 o/o to 14 % of the valves were calcific. Thus a study comparing the results of balloon mitral valvuloplasties with a different tech- nique in each of these two groups is valid. The patients in North American reports of mitral balloon dilatation are usually older and have more deformi- ties of the mitral valve.12v l3 However, the known mechanism of balloon valvulotomy of the mitral valve, the closely matched success of the two tech- niques in our series, and the acceptable results reported by Feldman and Carrolli with the Inoue technique in older patients with deformed valves all

would indicate that the overall results would proba- bly be about the same for the two techniques in ho- mogeneous North American populations.

In this study equally good results were achieved when patients with severe rheumatic mitral stenosis underwent balloon mitral valvuloplasty by means of either the single- or double-balloon technique. After balloon mitral valvuloplasty there was significant improvement in the NYHA functional class in both groups, with an adequate and significant increase in mitral valve area and decreases in the transmitral valve pressure gradient, mean left atria1 pressure, and pulmonary artery systolic pressure, together with an increase in the cardiac index. There was no significant statistical difference between the two groups with regard to clinical or hemodynamic im- provement.

The mitral valve areas achieved in both groups were similar to results from other reported series that used either of the two techniques: Previously pub- lished results of double-balloon mitral valvuloplasty reported the achievement of mitral valve areas be- tween 1.5 and 2.4 cm2 14; Inoue and Hung,15 on the other hand, reported achieving a mean mitral valve area of 1.97 ~fr 0.04 cm3 in 527 patients with the use of a single-balloon technique.

The incidence of technical failure was similar in both groups: 5% in group A and 3% in group B. The incidence of technical failure was 2.3 % in the Inoue series15 and 3% in the Vahanian series.23

In a similar study by Chen et a1.,16 comparing sin- gle- and double-balloon techniques, the success rate was higher (96 ‘% ) and the complication rate lower in the single-balloon group compared to the double- balloon group. However, in that study the incidence of technical failure with the double-balloon tech- nique was much higher (33%) than the usually accepted rate; this could possibly be due to the early learning phase of that group for the double-balloon technique.

The incidence of inadequate valve dilatation was 3 ‘$O in both groups A and B. The low incidence of in- adequate dilatation in group A, compared to other studies in which the double-balloon technique was used (9% to 11%),20,23 is related to our use of large balloon size (20 mm + 20 mm).

In both groups the balloon mitral valvuloplasty procedure produced very few complications, and there were no procedure-related deaths. Cardiac tamponade was the most serious problem encoun- tered-with an incidence of 1.7% in both groups- and it only occurred as a result of transseptal punc- ture. Tamponade as a complication of transseptal puncture occurs in 1% -3% in large series.15* 17,‘1

Volume 123

Number 6 Inoue versus double-balloon mitral valvuloplasty 1587

Perforation of the left ventricle has been reported in less than 2% in the double-balloon mitral valvulo- plasty technique. I7 The length of the Mansfield bal- loons and their sharp-tipped configuration contrib- ute in some instances to ventricular perforation.18, lg This problem was not encountered in either group in this study. In group A this could be the result of the use of pigtail balloons, whereas in group B the special design features of the Inoue balloon results in a “fail-safe” movement away from the apex of the left ventricle toward the mitral valve, locking onto the mitral valve during balloon inflation, making the risk of left ventricular perforation very low.14, l6

After balloon mitral valvuloplasty the incidence of an increase in MR of one grade or more was similar in the two groups (36% in group A; 31% in group B), and this was similar to findings in other reported se- ries (30% to 60%). 17, x 22 However, the incidence of moderately severe to severe MR was lower in group B, although it did not reach statistical significance: 8 70 and 3 % for groups A and B, respectively. An in- crease in MR of more than two grades occurs in 4% to 13 “0 in large series.17y 21, 22 The lower incidence in group B may be attributable to the stepwise dilata- tion, which was made possible by the design of the Inoue balloon, and also to the use of echo-Doppler imaging after each dilatation to assess the commis- sural split, the mitral valve area achieved, and the degree of MR. The detection of any increase in MR would indicate that further dilatation would carry the risk of a further increase. Such stepwise dilata- tion and echo-Doppler assessment between each di- latation is not easily feasible with the double-balloon technique.

In the double-balloon technique a major cause of MR, other than tear of the anterior or posterior leaf- let, is chordae rupture, caused mainly by the mala- lignment or entanglement of the balloon catheters between the chordae. Chordae rupture is less likely to occur with the use of the Inoue single balloon, because the balloon is advanced across the mitral valve slightly inflated, functioning as a flow-directed catheter, thus decreasing the chance of entanglement in the chordae.

Creation of an iatrogenic atria1 septal defect is an integral part of both procedures to pass the balloon from the right to the left atrium. In both groups there was no significant L:R shunt through an atria1 septal defect. The low incidence of atria1 septal defect in group A compared with that in other double-balloon series is a result of the use of two separate I4F trans- septal sheaths through which the balloons are ad- vanced into and pulled back from the left atrium. Also the low incidence of atria1 septal defect in

patients in group B in our series compares favorably with the experience of others; Chen et a1.,i6 who used 14F dilators and the Inoue technique, similar to us, did not find a significant incidence of atria1 septal defect.

The double-balloon technique involves two sepa- rate transseptal punctures with a 14F long sheath as described here or a single transseptal puncture with balloon dilatation of the atria1 septum and passage of two sets of balloon and wire devices across the atria1 septum, through the left atrium, across the mitral valve, and into the left ventricle. Positioning of the wires into the left ventricle leads frequently to ven- tricular dysrhythmia, resulting in hemodynamic dis- turbances. The Inoue technique, on the other hand, involves single transseptal puncture and single bal- loon dilatation of the mitral valve. Its special design allows the balloon to be stretched and “slenderized,” maintaining a low profile (4.5 mm), for passage across the atria1 septum. The Inoue balloon may be floated, similar to a flotation catheter, or directly steered into the left ventricle. The shorter inflation and deflation times (less than 3 seconds) and the lower inflation pressure (1 to 2 atm), compared to the slow inflation and deflation times and 3 atm pressure of conven- tional balloons, minimize the duration of hemody- namic disturbances.14r I5

The double-balloon technique is definitely more complex and cumbersome, and the mean screening time required is double that for the Inoue single-bal- loon technique. Inasmuch as one of the advantages of percutaneous balloon mitral valvuloplasty is the ability to repeat the process without the trauma of surgery, cumulative screening times must be re- garded as an important potential risk.

Few reports have been published on the use of bi- foil or trefoil ballooned catheters to dilate the stenotic mitral valve.24* 25 The procedure is reported by Pate1 et a1.26 to have a mean fluoroscopy time of 34 minutes, which approximates that for double-balloon mitral valvuloplasty. The procedure involves the use of a 10 mm diameter balloon catheter to dilate the trans- septal puncture. Overall the single-catheter bifoil or trefoil balloon technique may have some advantages over the double-balloon technique, but its advan- tages if any over the Inoue single-balloon technique are minimal.

In this series the cost to our institution of the dis- posable supplies used in the Inoue technique was 40 % more than the cost for the double-balloon tech- nique, but we believe that these costs are justified in light of the ease with which the Inoue balloon cath- eter is used because of its special design features.

Although the total cost of closed mitral valvotomy

1588 Abdullah et al. June 1992

American Heal Journal

may be lower than that of balloon mitral valvulo- plasty in third world countries, the reverse is true in North America.27 The surgeons at this institution do not perform closed mitral valvotomy; however, the overall cost comparison would be closer to the North American ratio than the third world model.

In conclusion, both the Inoue-single balloon and the double-balloon mitral valvuloplasty procedures are safe and effective nonsurgical modalities of treat- ment for severe rheumatic mitral stenosis in selected patients. Both techniques produce equally good re- sults with a low incidence of complications. There was no significant difference between the two groups with regard to clinical or hemodynamic improve- ment, mitral valve area achieved, and rate of compli- cations. The less complicated and easier Inoue single- balloon technique, although 40 % more expensive, justifies the extra cost involved.

We thank Janice Clarke-Piccioni and Marlene Bernardino for typing the manuscript.

REFERENCES

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

Inoue K, Owak T, Nakamura T, Kitamura F, Miyamoto N. Clinical application of transvenous mitral commissurotomy by a new balloon catheter. J Thorac Cardiovasc Surg 1984;87:394- 402. Lock JE, Khalilullah M, Shrivastava S, Bahl V, Keane JF. Percutaneous catheter commissurotomy in rheumatic mitral stenosis. N Engl J Med 1985;313:1515-8. Zaibag MA, Kasab SA, Ribeiro PA, Fagih MR. Percutaneous double balloon mitral valvotomy for rheumatic mitral steno- sis. Lancet 1986;1:757-61. Babic UU, Pejcic P, Djurisic Z, Vucinic M, Grujicic SM. Per- cutaneous transarterial balloon valvotomy for mitral stenosis. Am J Cardiol 1986;57:1101-4. McKav RG. Lock JE. Keane JF. Safian RD. Aroestv JM, Grossman W. Percutaneous mitral valvuloplasty in adult pa- tients with calcific rheumatic stenosis. J Am Co11 Cardiol 1986;7:1410-5. Palacios IF, Lock JE, Keane JF, Block P. Percutaneous trans- venous balloon valvotomy in a patient with severe calcific mi- tral stenosis. J Am Co11 Cardiol 1986;7:1416-9. Palacios IF, Block P, Wilkins G, Rediker D, Daggett W. Per- cutaneous mitral balloon valvotomy during pregnancy in a patient with severe mitral stenosis. Cathet Cardiovasc Diagn 1988;15:109-11. Rediker DE, Block PC, Abasacal VM, Palacious IF. Mitral balloon valvuloplasty for mitral restenosis after surgical com- missurotomy. J Am Co11 Cardiol 1988;11:252-6. Zaibag MA, Ribeiro PA, Al Kasab S, Halim M. Percutaneous double-balloon mitral valvotomy: results using different sized balloon catheters. J Am Co11 Cardiol 1987;9:82A. Hatle L. Aneelsen B. Tromsdal A. Non-invasive assessment of atrioventricmar pressure half-Time by Doppler ultrasound. Circulation 1979;60:1096-104.

11 Ribeiro PA, Fawzy ME, Arafat MA, Dunn B, Sriram R, Mer- cer E, Duran CG. Comparison of mitral valve area results of balloon mitral valvotomy using the Inoue and double balloon techniques. Am J Cardiol 1991;68:687-8.

12 Casale PN, Stewart WJ, Whitlow PL. Percutaneous balloon valvotomy for patients with mitral stenosis: initial and fol- low-up results. AM HEART J 1991;121:476-9.

13. Herrmann HC, Wilkins GT, Abascal VM, Weyman AE, Block

14.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27

PC, Palacios IF. Percutaneous balloon mitral valvotomy for patients with mitral stenosis. J Thorac Cardiovasc Surg 19889633-8. Feldman T, Carroll JD. Valve deformity and balloon mechan- ics in percutaneous transvenous mitral commissurotomy. AM HEART J 1991;121:1628-33. Inoue K, Hung JS. Percutaneous transvenous mitral commis- surotomy (PTMC): the Far East experience. In: Top01 E. Textbook of interventional cardiology, 1st ed. Philadelphia: WB Saunders, 1990:887-99. Chen CR, Huang ZD, Lo ZX, Cheng TO. Comparison of single rubber-nylon balloon and double polyethylene balloon valvu- loplastv in 94 patients with rheumatic mitral stenosis. AM HEART-J 199O;i19:102-11. Ruiz CE. Allen JW. Lau FY. Percutaneous double balloon valvotomy for severe rheumatic mitral stenosis. Am J Cardiol 1990;65:473-7. Robertson JM, de Virgilio C, French W, Ruiz C, Nelson RJ. Fatal left ventricular perforation using mitral balloon valvu- loplasty. Ann Thorac Surg 1990;49:819-21. Shawl FA, Domanski MJ, Yackee JM, Wish MH, Dullum M, Neimat S. Left ventricular rupture complicating percutaneous mitral commissurotomy: salvage using percutaneous cardio- pulmonary bypass support. Cathet Cardiovasc Diagn 1990; 21:26-7. Al Zaibag M, Ribeiro PA. The future of balloon valvotomy. In: Top01 E. Textbook of interventional cardiology. ed. 1st Phil- adelphia: WB Saunders, 1990:1912-25. Vahanian A, Michel PL, Cormier B, Vitoux B, Michel X, Slama M, Sarano LE, Trabelsi S, Ismail MB, Acar J. Results of percutaneous mitral commissurotomy in 200 patients. Am J Cardiol 1989;63:847-52. Abascal VM, Wilkins GT, Choong CY, Block P, Palacious IF, Weyman A. Mitral regurgitation after percutaneous balloon mitral valvuloplasty in adults: evaluation by Doppler echocar- diography. J Am Co11 Cardiol 1988,11:257-63. Vahanian A, Michel PL, Cormier B, Vitoux B, Roger V, Acar J. Mitral valvuloplasty: the French experience. In: Top01 E. Textbook of interventional cardiology. 1st ed. Philadelphia: WB Saunders, 1990:868-86. Vahanian A, Michel PL, Cornier B, et al. Results of percuta- neous mitral commissurotomy in 200 patients. Am J Cardiol 1989;63:135-6. Manga P, Chun R, Horak M, et al. Balloon mitral valvulo- plasty: multicenter study [Abstract]. Am J Cardiol 1989;63: 847-52. Pate1 J, Vythilingum S, Mitha AS. Balloon dilatation of the mitral valve by a single bifoil (2 x 19 mm) or trefoil (3 X 15 mm) catheter. Br Heart J 1990;64:342-6. Turi ZG, Reyes VP, Raju BS, Raju AR, Kumar DN, Rajago- pal P, Sathyanarayana PV, Rao DP, Srinath K, Peters P, Connors B, Fromm B, Farkas P, Wynne J. Percutaneous bal- loon versus surgical closed commissurotomy for mitral steno- sis: a prospective randomized trial. Circulation 1991;83:1179- 85.