PROGRESS IN CARDIOVASCULAR SURGERY. Congenital Mitral Stenosis and Mitral Insufficiency

Transcription

1 PROGRESS IN CARDIOVASCULAR SURGERY Congenital Mitral Stenosis and Mitral Insufficiency GEORGE W. B. STARKEY, M.D.* Boston, Massachusetts CONGENITAL MITRAL STENOSIS AND mitral insufficiency are rare, particularly as isolated defeets. They are more commonly associated with other cardiovascular anomalies such as patent ductus arteriosus, coarctation, septal defeets and corrected transposition. Due to current improvements in diagnostic accuracy and cardiac surgery, most children disabled by these lesions can be greatly improved by operation. A group of 12 patients at the Children's Hospital Medical Center with severe congenital mitral valvular disease treated surgically will be discussed. A mitral diastolic murmur was heard in all patients and a mitral systolic murmur in five. ELECTROCARDIOGRAM Right ventricular hypertrophy was seen in eight of the nine cases, P pulmonale in the majority. All were in normal sinus rhythm. ROENTGENOGRAM Right ventricular enlargement was noted in nine, left atrial enlargement in eight of nine, and increased pulmonary vascular markings in most cases (Figs. 1 and 2). CONGENITAL MLTRAL STENOSIS Only 18 cases of isolated congenital mitral stenosis have appeared in the literature according to Baker. 1 Additional cases have been reported, but in association with other cardiovascular anomalies. 2,3 Three cases are now being added to the original five reported in from the Children's Hospital Medical Center, bringing the total to 21. The clinical, laboratory, surgical and follow-up data of our eight cases plus a ninth case with an associated "balanced" patent ductus will be discussed. CLINICAL DATA There were five boys and four girls in this group ranging in age from two to 15 years. It is interesting to note that seven of the nine were under six. All had evidence of congestive heart failure. All had had a murmur noted under the age of two and one-half years except oné, and his was noted at the age of four years during a pre-school examination. There was no history or other evidence of rheumatic fever. *From the Children's Hospital Medical Center. 639 CATHETERIZATION DATA Preoperatively, six of the nine patients had right heart catheterization and four had left heart catheterization. The pulmonary artery mean pressures ranged from 30 to 75 mm. Hg. The pulmonay capillary or "wedge" pressures were from 15 to 26 mm. Hg, and the left atrial pressures (measured by direct dorsal or transseptal approach) from 21 to 30 mm. Hg with dominant "a" waves. SURGICAL MANAGEMENT Five patients had "closed" mitral commissurotomies with one death. Four patients had "open" or direct visión commissurotomies with two deaths. It is of interest to note that the three deaths were the youngest patients, in severe trouble at two years and two months, two and onehalf and three and one-half years of age. The patient with the "balanced" patent ductus had his mitral valve opened, but his ductus was not divided. He has done quite well for three years postoperatively. Anatomically, these valves tend to have thickened fibrous leaflets, poorly defined

2 640 GEORGE W. B. STARKEY, ^H^CHEST FIGURE 1: Congenital mitral stenosis. Left: Preoperative x-ray film of 12-year-old boy in chronic heart failure. Right: X-ray film of the same patient eight years postoperatively. This boy was able to finish school and now works every day. commissures, often short fused chordae tendineae and papillary muscles. The opening is very small and often eccentrically placed. This type of severe deformity is more commonly found in the sick young patient under three years of age. In the older child in trouble, one tends to find a more normal, funnelled valve with fusión of identifiable commissures and chordae tendineae. Because of the severe deformity of these valves, we prefer an "open" left- sided surgical approach to isolated congenital mitral stenosis at this time. FOLLOW-UP AND R E S U L T S Of the nine patients operated upon since 1955, three died at the time of surgery or shortly thereafter. One of the surviving six patients, originally done "closed," was reoperated upon four years later using an "open" method because of some residual stenosis and considerable insufficiency. He FIGURE 2: Congenital mitral stenosis. Left: Preoperative x-ray film of two and one-half-year-old boy with a history of congestive heart failure. Right: Postoperative x-ray film of the same patient three years later. He has continued his schooling and has practically no limitation of his activity.

3 Volume 43, No. 6 June 1963 CONGENITAL MITRAL STENOSIS AND INSUFFICIENCY 64I had severe pulmonary hypertension with systemic pressure in his pulmonary artery and severe pulmonary vascular changes. He died nine days postoperatively of chronic respiratory insufficiency and heart failure. The remaining five patients have been much improved clinically by operation; they go to school and carry on fairly normal activities. One or two of these patients operated upon seven and eight years ago show evidence of residual stenosis and insufficiency and may well come to re-operation in the future. CONGENITAL MLTRAL INSUFFICIENCY Congenital mitral insufficiency as an isolated lesión is rare. It is more commonly associated with other cardiovascular anomalies such as ostium primum, atrioventricular canal, patent ductus arteriosus, coarctation and corrected transposition. Several reports on surgical treatment have been most encouraging. Talner 5 studied ten patients with congenital mitral insufficiency and six were successfully operated upon. Four of these had isolated mitral insufficiency. Creech 8 reported a case in which he readily repaired a cleft mitral leaflet in a patient with associated supravalvular aortic stenosis. Carney 7 reviewed nine cases of congenital mitral insufficiency, seven of whom had an isolated lesión with two of the latter successfully operated upon. Ehrenhaft 8 described four cases treated surgically with good results. Our surgical experience is limited to three cases which will be briefly discussed. CLINICAL DATA Our three cases were all boys, eight months, 15 months, and 11 years oíd. They all had been in congestive failure. Their murmurs were first heard under the age of nine months. There was no history of rheumatic fever. They all had loud mitral systolic murmurs and lesser diastolic murmurs. ELECTROCARDIOGRAM All showed left ventricular hypertrophy and one showed some right ventricular hypertrophy. ROENTGENOGRAM These three patients had very large left atria and some increase in size of their left ventricles. CATHETERIZATION DATA The pulmonary artery mean pressures ranged from 42 to 65 mm. Hg, the pulmonary capillary or "wedge" mean pressures from 22 to 24 mm. Hg with tall "v" waves. SURGICAL TREATMENT AND FOLLOW-UP The first patient was 15 months oíd and weighed 18 pounds. He was very ill, requiring oxygen constantly in spite of excellent medical therapy. A "closed" mitral annuloplasty was done as an emergency procedure. The left atrium was aneurysmally dilated compressing the left main pulmonary artery and bronchus. The fibrous valve was flat and regurgitant posteriorly between the two leaflets. The anterior commissure was opened a few millimeters with a guillotine to increase the mobility of the leaflets. An annuloplasty was done by placing a few mattress sutures through the left atrial wall and the enlarged mitral ring. This greatly reduced the regurgitation and the patient has been essentially asymptomatic for the last four and one-half years. Figure 3 dramatically shows the diminution in heart size. The second case was an 11 -year-old boy, very disabled, tutored at home, who had "open" repair of his mitral regurgitation. He also had evidence of mild aortic and tricuspid insufficiency. His leaflets were thickened and did not come together in systole. His mitral annulus was very large. A few sutures through the ring from side to side diminished its size and brought the leaflets together. This boy now, nearly four and one-half years later, goes to high school and engages in mild athletic activities. He still has some evidence of mild regurgitation. The third case was an eight-month-old boy in congestive heart failure who had an "open" repair of his congenital mitral regurgitation using a left-sided approach. The

4 642 GEORGE W. B. STARKEY Diseases of the Chest FIGURE 3: Congenital mitral insufficiency. Left: Preoperative x-ray film of 15-month-old patient in congestive heart failure. Right: Postoperative x-ray film of the same patient four and one-half years later. H e is completely asymptomatic. left atrium was very large as noted in Fig. 4. The anteromedial leaflet was not particularly abnormal. The posterolateral leaflet was rudimentary, thickened and very short. The fused chordae tendineae and papillary muscles were a contiguous part of this leaflet. The posterolateral leaflet was tethered to the left ventricular endocardium and left a large defect through which the regurgitation occurred. The mitral annulus was FIGURE 4 : Preoperative x-ray film of patient with congenital mitral insufficiency in congestive heart failure at age eight months. somewhat enlarged. An attempt at reconstruction was made by doing an annuloplasty and incorporating in the mattress sutures small cylinders of compressed Ivalon to form a buttress against which the anteromedial leaflet could cióse during systole. This procedure seemed to diminish the mitral insufficiency strikingly. The patient had a series of cardiac arrests after the chest was closed and could not be resuscitated. Anatomically, congenital mitral insufficiency varíes greatly and has been well described by Edwards9 and others. The slit anteromedial leaflet seen in ostium primum is the commonest anomaly and is readily repaired before closing the septal defect. Enlargement of the mitral annulus due to poor apposition of the leaflets is more frequently encountered than was originally assumed and is quite amenable to surgical treatment. The grossly underdeveloped fibrous valve with thick, fused chordae and papillary muscles, often with an absent or vestigial posterior leaflet, is less commonly seen in a surgeon's experience. This type valve is often associated with other congenital defeets such as subendocardial fibroelastosis and other left-sided anomalies.

5 Volume 43, No. 6 June 1963 CONGENITAL MITRAL STENOSIS AND INSUFFICIENCY 643 As with congenital mitral stenosis, "open heart" repair of congenital mitral insufficiency in patients who are not doing well seems amply justified by our experience and that of others. DISCUSSION Congenital mitral stenosis and mitral insufficiency are rare, particularly when they are isolated lesions. Although they are often associated with other cardiovascular anorrialies, they are frequently the most significant lesions. The presence of a mitral diastolic murmur, right-sided hypertensiori, pulmonary venous obstruction and elevated left atrial pressure are found in practically all cases of congenital mitral stenosis. In congenital mitral insufficiency one finds a large left atrium, a mitral systolic murmur, left ventricular hypertrophy, tall "v" waves in left atrial pressure tracings and often angiocardiographic evidence of free regurgitation from the left ventricle into the left atrium. Surgically, an "open heart" approach to these disabling congenital mitral valvular lesions seems logical. STJMMARY Nine cases of congenital mitral stenosis and three cases of congenital mitral insufficiency treated surgically are reported. The clinical, radiologic, electrocardiographic, hemodynamic and surgical aspects of these cases are briefly reviewed. There were three initial deaths among the congenital mitral stenosis patients. A fourth death occurred following re-operation four years after the first operation. There was one operative death among the three patients with congenital mitral insufficiency. All survivors have been much improved clinically. REFERENCES 1 BAKER, C. G., BENSON, P. F., JOSEPH, M. C. AND Ross, D. N.: "Congenital Mitral Stenosis," Brit. Heart ]., 24:498, ELLIOTT, L. P., ANDERSON, R. C., AMPLATZ., K., LILLEHEI, C. W. AND EDWARDS, J. E.: "Congenital Mitral Stenosis," Pediatrics, 30: 552, ROBERTS, W. C., GOLDBLATT, A., MASÓN, D. T. AND MORROW, A. G.: "Combined Congenital Pulmonic and Mitral Stenosis," New Engl J. Med., 267:1298, STARKEY, G. W. B.: "Surgical Experiences in the Treatment of Congenital Mitral Stenosis and Mitral Insufficiency," ]. Thor. and Cardio. Surg., 38:336, TALNER, N. S., STERN, A. M. AND SLOAN, H. E.: "Congenital Mitral Insufficiency," Circulation, 23: CREECH, O., LEDBETTER, M. K. AND REEMTS- MA, K.: "Congenital Mitral Insufficiency with Cleft Posterior Leaflet," Circulation, 25:390, CARNEY, E. K., BRAUNWALD, E., ROBERTS, W. C., AYGEN, M. AND MORROW, A. G.: "Congenital Mitral Regurgitation. Clinical Hemodynamic and Angiocardiographic Findings in Nine Patients," Am. J. Med., 33:223, EHRENHAFT, J. L., FISHER, J. M. AND EHMKE, D. A.: "Non-rheumatic Mitral Insufficiency in Children," Arch. Surgery, 86:104, EDWARDSJ J. E., BURCHELL, H. B., BRANDEN- BURG, R. O., MARSHALL, H. W., WOOD, E. H., GUIDRY, L. D., CALLAHAN, J. A. AND ELLIS, F. H.: "Management of Mitral Insufficiency A Symposium," Proc. Staff Meeting, Mayo Clin., 33:497, HEMODYNAMICS AND TISSUE OXYGEN SUPPLY On the basis of investigations of hemodynamic factors and parameters influencing tissue oxygen supply, it was determined that in two cases of congenital, chronic methemoglobinemia (idiopathic) oxygen lack is compensated by an increase in circulatory rate and a rise in cardiac output. The increased afflnity of Hgb and 0 2, which occurs in methemoglobinemia, is counteracted by metabolic acidosis. KUZNETSOV, V. I. AND KUSHAKOVSKII, M. S.: "Hemodynamics and Tissue Oxygen Supply in Patients with Chronic Methemoglobinemia," Cor et Vasa, 4:281, 1962.