Open mitral valvulotomy

[Diagnosis and differential therapy of mitral stenosis]

Clinical symptoms and diagnostic findings in patients with mitral stenosis are usually determined by the extent of the stenosis. Compared to a normal mitral valve area (MVA) of > 4 cm2, MVA in patients with severe mitral stenosis is usually reduced to < 1.5 cm2. In older patients symptoms are frequently influenced by concomitant diseases (e.g. atrial fibrillation, arterial hypertension or lung disease). An important diagnostic element besides anamnesis, auscultation, ECG and chest X-ray is echocardiography, which is required in order to measure non-invasively and reliably the mitral valve gradient (MVG), the MVA and morphologic changes to the valves, as well as concomitant valvular disease, ventricular functions and, where appropriate, left-atrial thrombi. In addition to the surgical treatment of patients with severe mitral stenosis, which has been an established procedure for 50 years, percutaneous balloon mitral valvuloplasty (MVP) has recently established itself as an alternative option. At the current time, the Inoue technique seems to display the most advantages. Following transseptal puncture, the Inoue balloon is guided transvenously into the left atrium and then into the left ventricle using a special support wire. The balloon is short and soft. Its special unfolding character enables it to be placed securely in the mitral valve without any risk of ventricular perforation (Figure 1). As with surgical commissurotomy, balloon valvuloplasty leads to a separation of fused commissures. This results in a significant reduction of MVG, accompanied by an increase in the MVA (Figure 2). The results and success of MVP are influenced by the morphology of the valves and the changes to the subvalvular apparatus. In randomized studies, the results of surgical commissurotomy were comparable with those of balloon mitral valvulotomy. In our hospital, an increase in MVA from 1.0 to 1.8 cm2 could be achieved in 899 patients (mean age 56 +/- 3 years). In younger patients with less significantly changed valves, the results were correspondingly more favorable than in older patients (Figure 3). Provided valve morphology is suitable, a relapse following previous surgical commissurotomy is not a contraindication for MVP. The MVP complication rate is very low in skilled hands: mortality is below 1%; mitral insufficiency occurs in 3 to 10% of interventions; we observed a severe mitral insufficiency in 5% of our patient group. Thromboembolic complications may be prevented after exclusion of atrial thrombi by transesophageal echocardiography. The occurrence of a hemodynamically significant atrial septum defect is a very rare event. The mid-term results (5 to 10 years) and the low restenosis rate following MVP in patients with suitable valves are comparable with those of surgical commissurotomy. In older patients with considerably changed, calcified and fibrotic valves, restenosis may be expected within 1 to 5 years. In these patients MVP represents no more than a palliative intervention in order to prolong the point of surgery, for example in patients where a concomitant aortic valve disease in itself is not yet an indication for surgery. Special indications are to be found in young patients with severe mitral stenosis yet few symptoms, in pregnant females and in emergency situations, as well as in patients with Grade II mitral stenosis with intermittent atrial fibrillation. Catheter therapy is much less invasive than surgery. In case of failure the patient still has the option of surgical therapy. Patients with morphologically significantly altered valves usually receive a valve replacement since an unsuccessful reconstruction would lead to a second operation within a very short time interval. Contraindications for MVP are thrombi in the left atrium, a previously existing > Grade II mitral regurgitation and marked, degenerative destruction of the subvalvular apparatus or extensive calcification of the valves. MVP thus represents a significant addi

Percutaneous balloon valvuloplasty

In the technique of percutaneous balloon valvuloplasty, one or more large balloons are inserted percutaneously and then inflated across a stenotic valve to decrease the degree of obstruction. Currently, the procedure is being performed for patients with pulmonic, mitral, or aortic stenosis. The results vary according to the type of valve and the age of the patient. In patients with pulmonic stenosis, balloon valvuloplasty can be performed safely and the results are excellent. Therefore, at many institutions it is the procedure of choice for the treatment of isolated pulmonic stenosis. In patients with mitral stenosis, the results depend on the morphologic features of the stenotic valve. In patients with highly calcified and fibrotic mitral valve leaflets, the risks of the procedure are increased and the results are suboptimal. In experienced hands, however, balloon valvuloplasty is excellent for patients with a pliable, noncalcified mitral valve or those for whom operation imposes an extremely high risk. The use of balloon valvuloplasty for aortic stenosis has been limited to the frail, elderly patient who either is not a surgical candidate or is at high risk for operation. Although mortality and restenosis rates are high on short-term follow-up, aortic balloon valvuloplasty provides palliation of symptoms in many patients who otherwise would have been unable to undergo any intervention. Long-term follow-up is necessary for determining the ultimate role of balloon valvuloplasty in cardiology.

Balloon valvuloplasty in calcified aortic stenosis: a cause for caution and alarm

Balloon dilation by the percutaneous route has recently been recommended as an alternative to surgical intervention in the management of calcified aortic valvular stenosis. To investigate the validity of balloon valvuloplasty, this procedure was carried out in the operating room under direct vision in 30 patients just prior to excision and replacement of the ossified aortic valve. Changes induced by balloon dilation were evaluated by visual inspection as well as by geometric measurements. By visual observation, balloon valvuloplasty did not have a detectable impact on the valvular anatomy in about 19 of the patients and induced enlargement of the functional aortic orifice judged as "minimal" or "moderate" in only 11. In no patient was there a substantial increase in the functional orifice size. These findings were supported by geometrical measurements. Therefore, we believe that the virtues of this procedure have been grossly overstated by its proponents and that it should be offered only to patients who present a truly forbidding risk by standards of modern surgery.

Closed mitral valvotomy during pregnancy. A 20-year experience

Closed mitral valvotomy for rheumatic mitral stenosis was performed on 126 pregnant women (average duration of pregnancy c. 21 weeks), 91% of whom were in NYHA functional class III or IV. Associated functional tricuspid regurgitation was present in 47 (37%) of the women, and 102 (81%) had critical mitral stenosis (digitally assessed valve area less than 1 cm2). There was no surgical mortality. Postoperatively 84% of the women were in NYHA class I. Clinical evidence of pulmonary artery hypertension and tricuspid regurgitation regressed postoperatively in most patients. Full-term normal delivery was achieved in 82% of the pregnancies, with total fetal mortality 6%. There were no congenital abnormalities and the infants' progress was normal. At 5-year follow-up 86% of the women were in NYHA class I or II and at 10 years the figure was 60%. The restenosis rate was 2%/year and the late mortality 3.3%. Closed mitral valvotomy during pregnancy thus was safe and reliable, giving significant functional and clinical improvement without adversely affecting the fetus.

Limited value of balloon dilatation in calcified aortic stenosis in adults: direct observations during open heart surgery

Percutaneous balloon dilatation was recently recommended as a treatment for management of calcified aortic valvular stenosis. This procedure was initially reserved for patients who were not considered surgical candidates; it is now regarded by some as an acceptable alternative for valve replacement. To investigate the validity of this postulate, balloon valvuloplasty was performed under direct vision in the operating room in 16 patients just before excision and replacement of their ossified aortic valve. Changes after valvuloplasty were evaluated by inspection as well as by geometric measurements. The authors found that balloon valvuloplasty did not make a detectable impact on valvular anatomy in about two-thirds of the patients and induced enlargement of the functional aortic orifice judged as "minimal" or "moderate" in one-third of the cases. In no patient was there significant increase in the functional orifice size. Other investigators have shown that hemodynamic and clinical improvement may be induced in some patients by small increases in the aortic orifice; based on the observations herein, such an improvement, if it occurs at all, would be short-lasting; the procedure should be offered only to those who present truly prohibitive risk by standards of modern surgery.

Percutaneous catheter commissurotomy in rheumatic mitral stenosis

We attempted percutaneous transcatheter-balloon mitral commissurotomy in eight children and young adults (9 to 23 years of age) with rheumatic mitral stenosis. The atrial septum was traversed by needle puncture, and an 8-mm angioplasty balloon was advanced over a guide wire. The atrial septal perforation was then dilated to allow passage of the valvuloplasty balloon catheter (18 to 25 mm) across the mitral annulus. Inflation of the transmitral balloon decreased the end-diastolic transmitral gradient temporarily in all patients (from 21.2 +/- 4.0 mm Hg [mean +/- S.D.] to 10.1 +/- 5.5 mm Hg; P less than 0.001). The immediate decrease in the gradient was associated with increases in cardiac output (from 3.8 +/- 1.0 to 4.9 +/- 1.3 liters per minute per square meter of body-surface area; P less than 0.01) and in the calculated mitral-valve-area index (from 0.73 +/- 0.29 to 1.34 +/- 0.32 cm2 per square meter; P less than 0.001). Murmur intensity diminished immediately after commissurotomy in all patients. The greatest reduction in pressure gradient (76 to 95 per cent) occurred when the largest balloon (inflated diameter, 25 mm) was used in the smallest patients (0.9 to 1.2 m2). The balloon commissurotomy produced minimal mitral regurgitation in only one child. Follow-up catheterization (at two to eight weeks) demonstrated persistence of hemodynamic improvement with evidence of partial restenosis in one patient. These early results indicate that balloon mitral commissurotomy can be a safe and effective treatment for children and young adults with rheumatic mitral stenosis.

Closed mitral valvotomy: early results and long-term follow-up of 3724 consecutive patients

Between 1956 and 1980 closed mitral valvotomies were performed in 3724 consecutive patients (male:female ratio 1.1:1) with mitral stenoses. Their ages ranged from 6 to 69 years, with a mean (SD) of 27.3 (9.3). Mitral stenosis in the younger age group is a unique condition and a great majority of these patients rapidly develop significant pulmonary hypertension and congestive cardiac failure. In this study a large number of subjects belonged to functional class IV (41.5%). Hospital mortality was 1.5% over the last 5 years. After valvotomy, 11 patients (0.3%) developed severe mitral regurgitation that made valve replacement necessary in the immediate postoperative period. Early postoperative embolism occurred in 0.4% of those who were in atrial fibrillation and had preoperative anticoagulation whereas it occurred in 0.95% of those in sinus rhythm who had no anticoagulation. Late postoperative embolism occurred at a rate of 0.3 to 1.6 per 1000 patients per year over a 20 year period. Rheumatic reactivity occurred at a rate of 1.3 to 2.2 per 1000 patients per year during the same period. Rate of occurrence of restenosis varied from 4.2 to 11.4 per 1000 patients per year between the fifth and fifteenth year of follow-up. Closed transventricular revalvotomy for restenosis was accomplished in 130 subjects with a 6.7% mortality. Excellent symptomatic improvement was evident in 86% of long-term survivors at the end of 15 years. Actuarial survival was 95%, 93.1%, 89.5%, and 84.2% at 6, 12, 18, and 24 years, respectively, after closed mitral valvotomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Intracardiac surgery in pregnant women

A survey of members of The Society of Thoracic Surgeons was undertaken to obtain information on experiences with cardiac operations in pregnant women. The experiences reported were highly successful, with only 1 maternal death in 68 procedures utilizing cardiopulmonary bypass and more than 80% survival of fetuses. Cardiac operations in pregnant patients probably can be made safer by avoidance of perfusion hypothermia and by use of fetal heart and uterine monitoring. When valve replacement is necessary, use of biological valves is recommended to avoid the necessity for anticoagulation.

Open mitral valvotomy: fourteen years' experience

During the period 1968 to 1980, 222 patients with mitral valve disease in which stenosis was the dominant lesion were admitted under the care of the senior author. All patients presented with severe dyspnoea (NYHA grades 3 or 4). One hundred and fifty seven (71%) patients were treated by open mitral valvotomy. One patient died within 30 days of operation (0.6% hospital mortality) and one suffered a transient cerebrovascular accident. One hundred and twenty four (70%) patients were followed up for one to 14 years (mean 7.5 years). There were seven late deaths. Actuarial curves predict the 90.2% 10 year survival after open mitral valvotomy. Eight patients required mitral valve replacement for restenosis corresponding to 16% at 10 years. The remaining patients are in NYHA grades 1 and 2.

Early open radical commissurotomy: surgical treatment of choice for mitral stenosis

Between 1967 and 1979, 411 patients underwent surgical treatment of isolated mitral stenosis at our institution. Open radical mitral commissurotomy was performed in 150 patients (1967-1978; mean follow-up, 46 months; range, 4 to 116 months). Mitral valve replacement using a porcine prosthesis was performed in 74 patients (1976-1979; mean follow-up, 23 months; range, 2 to 48 months). Mitral valve replacement with a cloth-covered Starr-Edwards prosthesis was performed in 187 patients (1967-1975; mean follow-up, 45 months; range, 2 to 106 months). Preoperative characteristics were similar in the three groups. The open commissurotomy and Starr-Edwards groups were followed up to 9 years and the porcine valve group up to 4 years, with 97% follow-up in each group. Life-table analysis (6-month intervals) of all postoperative complications revealed significantly greater complication-free survival for patients who had open radical commissurotomy compared with Starr-Edwards (p less than 0.05) valve replacement. Similar analysis of thromboembolic and warfarin-related complications revealed significantly fewer complications in commissurotomy patients. No significant differences were found (p greater than 0.05) when comparing the need for subsequent reoperation in each group. Operative mortality following open radical mitral commissurotomy (0%; 0 out of 150) was significantly less (p less than 0.05) than after mitral valve replacement in both porcine (8.1%; 6 out of 74) and Starr-Edwards (11.2%; 21 out out 187) groups. Life-table analysis of late cardiac-related mortality revealed a significantly greater cumulative survival rate for the commissurotomy versus the Starr-Edwards groups at all intervals from 12 to 108 months (100 versus 84 +/- 5%, p less than 0.05). No significant differences were noted between commissurotomy and porcine valve groups during the 4-year follow-up period (100 +/- 0% versus 96 +/- 3%, p greater than 0.05). Based on these findings, we conclude that when the anatomy is favorable, the surgical treatment of choice for isolated mitral stenosis is open radical mitral commissurotomy.

A 25-year experience with the closed method of treatment in 139 patients with mitral stenosis

A 25-year experience with 139 patients undergoing closed mitral commissurotomy is reviewed. The primary indication for closed mitral commissurotomy was mitral stenosis, but 24 patients also had other less important valvular defects. Preoperatively, all patients were in New York Heart Association (NYHA) Functional Class III or IV. Average age was 46 years (range, 18 to 77 years). There were 24 men and 115 women. No further operation after initial closed mitral commissurotomy was required in 68% of the patients (95 patients), and NYHA Functional Classification was improved in 93%. Postoperative complications occurred in 3%, and operative mortality was 2.0%. Follow-up revealed restenosis in 6% of the patients, mitral regurgitation in 14%, complications in 7%, and late deaths in 3%. Reoperation, required in 32% (44 of 139 patients), included a second closed mitral commissurotomy (21 patients), open mitral commissurotomy (3), mitral valve replacement (MVR) (18), and MVR after a second closed mitral commissurotomy (2). Improvement in NYHA classification was found in 82% of these patients. Operative mortality was 9.5% for patients having a second closed mitral commissurotomy and 20% for those having MVR.

Long-term results of open mitral valvuloplasty

The long-term results of open mitral valvuloplasty in 51 patients are assessed. At the time of operation, 4 patients were in New York Heart Association Functional Class II, 41 in Functional Class III, and 5 in Functional Class IV. Group I (14 patients) had had previous closed mitral commissurotomy. Three patients died 2 to 4 years after open valvuloplasty. One patient died following valve replacement 7 years after the open valvuloplasty. Five others required mitral valve replacement 1 to 12 years following open valvuloplasty. Only 4 of the 14 patients are in Functional Class I or II 10 to 15 years following valvuloplasty. Group II (36 patients) had never undergone a previous mitral operation. Four of them died of progressive myocardial failure 4 to 6 years following valvuloplasty. One patient died of carcinoma of the lung 2 years postoperatively. Six patients underwent valve replacement 6 to 11 years following initial operation. Twenty-six have survived for at least 10 years without additional operation. Fourteen are in Functional Class I, and 12 are in Funcitonal Class II. Open mitral valvuloplasty allows for (1) accurate commissurotomy and careful subvalvular dissection, (2) direct vision to diagnose clot in the left atrial appendage or left atrium proper, (3) accurate assessment of residual or induced mitral regurgitation and immediate repair, and (4) reasonable operative mortality and morbidity.

The advantages of open mitral commissurotomy for mitral stenosis

Mitral commissurotomy is the treatment of choice for mitral stenosis. If this is not feasible, replacement of the valve becomes necessary. Open commissurotomy has been performed at Loyola University Medical Center, Maywood, Ill, in 105 patients since 1970. The mean age was 45 years. The indication for surgery was heart failure in 92 of the cases. Sixty of the patients were in class 3 of the New York Heart Association (NYHA) classification. Eighty-five underwent open mitral commissurotomy alone. This was not feasible in 42 patients scheduled for it who required valvular replacement. Twenty-five patients had a left atrial thrombus. Two patients died, one from aortic dissection and the other from acute infarction in the perioperative period. Ninety-eight patients are NYHA class 1 or 2 at present. Two patients required valvular replacement following the commissurotomy. The low mobidity and mortality with excellent long-term results support our contention that open mitral commissurotomy is the treatment of choice for mitral stenosis.

Reconstructive valve surgery

Despite continued refinement of heart valve prostheses, valve replacement carries risks of thromboembolic, mechanical, and infectious complications, and long-term success is further limited by the eventual wear of prosthetic parts. In many patients with congenital or acquired valve diseases, valve function may be improved, if not restored, by reconstructive techniques, prosthetic replacement being thereby avoided or delayed. This review examines the current status of reconstructive procedures for management of diseased valves, with emphasis on long-term results and post-operative hemodynamic studies. In many instances the choice between reconstruction and replacement of a diseased valve remains controversial. The documented success of selectively applied reconstructive techniques, however, weighs against expedient decisions for prosthetic replacement and supports a continuing search for new techniques.

Advantages of open mind commissurotomy using a triple-orifice technique

Our experience over an eight-year period with the operative relief of mitral stenosis is reviewed and detailed. Of the 106 patients in the series, 80% had minimal or no calcification, 17% had moderate calcification, and 4% had severe calcium deposits in the valve. Four patients have required reoperation for recurrent stenosis, with valve replacement in 3 and a second commissurotomy in the fourth. Left atrial thrombus was encountered in 16%, and no patient with thrombus experienced embolization in the postoperative period. One postoperative death occurred within 30 days, and a single late death occured 35 days after operation. For the scarred, retracted mitral valve we have utilized a multiple-orifice technique that provides maximal flow without the risk of inducing significant mitral insufficiency.