Congenital Mitral Insufficiency

Transcription

1 Congenital Mitral Insufficiency Results in Unusual Lesions Bruno J. Messmer, M.D., Grady L. Hallman, M.D., and Denton A. Cooley, M.D. A lthough mitral insufficiency is commonly associated with septal defects of the endocardial cushion type, it is extremely rare as an isolated lesion of congenital origin. Few reports exist on mitral insufficiency due to a single cleft or to multiple tissue defects in either of the valve which is not associated with a septal defect of the endocardial type [l, 4, 6-8, 10, 15, 181. Involvement of the mitral valve in patients with Marfan s syndrome has been reported as a cause of congenital mitral insufficiency [14, 161. While these lesions are easily recognized as being primary congenital types, some forms of mitral regurgitation occur in combination with coarctation, congenital aortic stenosis, endocardial fibroelastosis, corrected transposition of the great vessels, and anomalous origin of the left coronary artery from the pulmonary artery [7, 8, 151. In these special cases it is often difficult to decide whether the mitral lesion is primary or secondary. Between 1961 and 1969, 15 children and 3 adults have undergone mitral valve operations for unusual congenital lesions at the Texas Heart Institute. Patients with corrected transposition are not included in this series since their mitral insufficiency originates at the anatomically tricuspid valve. CLINICAL MATERIAL AND RESULTS MITRAL INSUFFICIENCY DUE TO PRIMARY CONGENITAL DEFECTS OF THE VALVE Cleft Septal Leaflet. Isolated cleft of the septal, a rare anomaly, was found in 3 children and 2 adults. All patients were female, and they ranged in age from 5 to 48 years. The cleft was the only cardiac malformation in 3 of the 5 patients. One patient had an additional Type I1 atrial septal defect, and another had a defect of the muscular part of the ventricular septum. Clinical symptomatology ran the gamut from reduced exercise tolerance to mild congestive heart failure, but generally i,t was of minimal severity. The electric axis in the electrocardiogram ranged from Oo to + 120O. Each patient underwent cardiac catheterization and angiocardiography, which gave visual evidence of mitral insufficiency From the Texas Heart Institute of St. Luke s Episcopal and Texas Children s Hospitals, Houston, Tex. Presented at the Sixth Annual Meeting - of The Society of Thoracic Surgeons, - Atlanta, Ga.. Jan , Address reprint requests to Dr. Messmer, Texas Heart Institute, P.O. Box 20345, Houston, Tex THE ANNALS OF THORACIC SURGERY

2 ~ Congenital Mitral Insuficiency and showed a slightly elevated pulmonary artery pressure in 4 patients (mean pulmonary artery pressure of 55 mm. Hg). The child with the additional Type IV ventricular septal defect had pulmonary hypertension and a mean pressure of 55 mm. Hg. In only 1 patient was the correct diagnosis of cleft mitral established prior to operation. This patient presented a Oo axis in the electrocardiogram and had an atrial septal defect of the secundum type. The cleft was in the classic position in the middle of the in all patients, but it varied in depth. Plastic repair of the mitral valve was possible in 3 patients. Interrupted sutures of 4-0 Tycron were used to repair the cleft. Two patients required concomitant mitral annuloplasty to establish complete valvular competence, Plastic repair was not possible in 1 child and 1 adult. The valves were replaced, one by a Starr-Edwards ball prosthesis and the other by a Kay-Shiley disc prosthesis. Follow-up studies after six months to eight years revealed good clinical results, but pulmonary hypertension persisted in the patient who had an additional Type IV ventricular septal defect (Table 1). Defects of the Mural Leaflet. Five patients (3 male, 2 female) had defects of the mural. A single eccentrically situated cleft was found in 3 patients, and multiple notches at the free edge resulting in a scalloped mural were found in 2. Three patients had an associated atrial septal defect of the secundum TABLE 1. PRIMARY CONGENITAL MITRAL INSUFFICIENCY Type of Patient's Lesion Age (yr.) Valve Defect Type of Operation Result Isolated insufficiency 10 Cleft septal Cleft septal Plastic repair, mitral annuloplas t y Plastic repair, mitral mitral annuloplas ty Cleft septal Mitral valve replacement 9 Cleft mural Mitral valve replacement Mitral insufficiency, ASD 5 11 Cleft septal Cleft mural closure ASD Plastic repair, closure ASD Plastic repair, closure ASD 67 Type I1 13 Cleft mural 16 Scalloped mural Mitral valve Scalloped mural Mitral annuloplasty, Mitral annuloplasty, repiacemen t closure ASD Mitral 6 Cleft septal Plastic repair Persistent insuffi- pulmonary ciency, hyper- VSD tension Type IV Mitral 4- Ruptured chordae Mitral valve Died 12 hr. insuffi- tendineae replacement postciency, operatively Marfan's syndrome ASD = atrial septal defect; VSD = ventricular septal defect. VOL. 10, NO. 5, NOVEMBER,

3 MESSMER, HALLMAN, AND COOLEY type, and one had congenital atrioventricular block. The electrocardiographic axis ranged between +30 and +120 in 4 patients but was -looo in the fifth. Preoperative rardiac catheterization and angiographic studies were performed in each patient. The mean pulmonary artery pressure ranged between 16 and 23 mm. Hg, and marked V waves were usually seen in the pulmonary wedge tracing. Two patients underwent plastic reconstruction of the mitral valve. In 1 patient repair of a cleft and annuloplasty, and in the other, annuloplasty alone, resulted in competent valves. Replacement of the valve was necessary in 3 patients; Kay-Shiley prostheses were inserted in 2 children, and an adult received a Wada- Cutter valve. Four months to three and one-half years after operation all patients are doing well (Fig. 1; see Table 1). Marfan's Syndrome with Involvement of the Mitral Valve. While involvement of the ascending aorta in patients with Marfan's syndrome often results in aneurysm and aortic insufficiency, mitral insufficiency due to direct involvement of the connective tissue within the valve is rare. One such patient 1171 had first been seen at the age of 3 years with a slightly elevated pulmonary capillary wedge pressure (14/4, mean 10 mm. Hg) and an enlarged left atrium. Symptoms of congestive heart failure had been treated successfully with digitalis. One year later she was admitted to the hospital with severe, therapy-resistant pulmonary edema. Emergency operation was required. The mitral valve was grossly incompetent due to ruptured chordae tendineae of the mural. Reconstruction was impossible, so the valve was excised and replaced with a No. 32 Cooley- Cutter low-profile disc prosthesis. Immediately after operation the child did well, but she died twelve hours later from a sudden cardiac arrest. Histological examination revealed many mucopolysaccharide deposits in the connective tissue of the mitral valve and chordae. The other cardiac valves were similarly affected. There was typical medial degeneration in the ascending aorta. MITRAL INSUFFICIENCY ASSOCIATED WITH OTHER CONGENITAL LESIONS Coarctation and Mitral Insuficiency. Three children, l%, 3%, and 5 years of age, had mitral regurgitation and coarctation. In 2 the coarctation had been resected three years and one year, respectively, before mitral valve operation became mandatory. The third patient required mitral valve replacement two weeks after resection of the coarctation because the first operation did not improve his cardiac status. Each patient was severely ill at the time of mitral valve operation and had marked elevation of the pulmonary artery and left ventricular end-diastolic pressures. All patients presented signs of left ventricular hypertrophy and left atrial enlargement in the electrocardiogram. Evidence of right ventricular hypertrophy was present in 2 patients. In 1 patient pathological and anatomical findings included fibrosclerotic s, atypical attachment of chordae tendineae, and endocardial changes suggestive of endocardial fibroelastosis. The second patient had fibrosclerotic s; the third showed a cleft in the septa1, notching defects in the mural, and endocardial fibroelastosis. Valve replacement with Kay-Shiley disc prostheses resulted in marked improvement in 2 of the 3 patients. The third patient, a l%-year-old child, died from a sudden cardiac arrest eight hours after operation. At autopsy the prosthesis appeared to be well placed and capable of normal function. Extensive endocardial fibroelastosis was present in the left ventricle. One of the survivors did well until she experienced several episodes of cerebral embolism; in spite of anticoagulant therapy, she died three years after operatioil from acute pulmonary edema due to a thrombosed prosthesis. The third patient is still alive and in excellent condition (Table 2). Endocardial Fibroelastosis and Mitral Znsuficiency. Congenital mitral regurgitation was surgically treated in 3 children with endocardial fibroelastosis 4.52 THE ANNALS OF THORACIC SURGERY

4 Congetiitnl Mitinl Insuficicncy A B FIG. 1. (A) Preopeiataue clie~t goeiitgenogiams (posteroanterior and right oblique) of a 13-yeai-old patient with primary congenital mitral insuficiency (scalloped mural ) and ostium secundum atrial septal defect. (B) Control chest roentgenograms three years,after mitral valve rrplacement with a Kay-Shiley prostheyis and closure of the atrial septal defect.

5 MESSMER, HALLMAN, AND COOLEY TABLE 2. MITRAL INSUFFICIENCY ASSOCIATED WITH OTHER CONGENITAL LESIONS Type of Patient's Lesion Age (yr.) Valve Defect Type of Operation Result Coarctation, mitral insufficiency Endocardia1 fibroelastosis, mitral insufficiency Anomalous '7 left coronary, mitral insufficiency 1% 3% 5 2% 3% 5 8 Cleft septai, scalloped mural Fibrosclerotic valve, dilated annulus Fibrotic valve, dilated annulus Fibrotic valve, dilated annulus Fibrotic valve, dilated annulus Fibrotic valve, dilated annulus Elongated chordae, dilated annulus Mitral valve replacement Mitral valve replacement Mitral valve replacement Mitral annuloplasty Mitral annuloplasty Mitral valve replacement Mitral annuloplasty, ligation of left coronary Died 8 hr. postoperatively of myocardial failure Died 3 yr. postoperatively of thrombosed valve Died 8 hr. postoperatively of myocardial failure Died in operating room of myocardial failure Died in operating room of myocardial infarction (ages 234, 3% and 5 years) (Table 2). All were in severe congestive heart failure prior to operation. Cardiac catheterization revealed pulmonary hypertension in 2 patients with systolic pulmonary artery pressures of 100 mm. Hg and mean pulmonary artery pressures of 82 and 75 mm. Hg, respectively. The third patient had an elevated pulmonary artery pressure of 35/12 with a mean of 25 mm. Hg L and a V wave in the left atrium of 30 mm. Hg. Principal findings at operation in all 3 patients were marked dilatation of the mitral annulus and some fibrosis of the s. Valvular competence was established by annuloplasty in 2 patients, 1 of whom also required tricuspid annuloplasty. The patient who had the additional tricuspid annuloplasty died eight hours after operation from myocardial failure. At autopsy areas of endocardial fibroelastosis were found in both ventricles. Some scattered fibrosis of the myocardium was also present. The third patient had mitral valve replacement with a No. 2 Starr-Edwards prosthesis but died in the operating room from myocardial failure after multiple attempts at defibrillation. Autopsy revealed 454 THE ANNALS OF THORACIC SURGERY

6 Congenital Mitral In.suficioicy the changes typical of endocardia1 fibroelastosis. Cardiac enlargement has gradually subsided in the 1 surviving patient (Fig. 2). Five years after operation recatheterization demonstrated normal hemodynamics, and today, in his eighth postoperative year, the patient has few symptoms but still requires digitalis therapy. Anomalous Left Coronary Artery and Mitral Insufficiency. Mitral regurgitation is a relatively common finding in patients in whom the left coronary artery A B FIG. 2. (A) Preoperative chest roentgenograms (posteroanterior and left lateral) of a 2%-year-old child with myocardial fibroelastosis and mitral insuficiency. (B) Control chest roentgenograms six years after mitral annuloplasty. VOL. 10, NO. 5, NOVEMBER,

7 MESSMER, HALLMAN, AND COOLEY arises from the pulmonary artery. Among 9 patients who underwent operation for this anomaly, 6 had a murmur of mitral insufficiency although only 1, an 8-year-old boy, required simultaneous operation on the mitral valve. Unfortunately, when this operation was done in 1961 the accepted procedure was ligation of the anomalous coronary artery, which resulted in this case in acute myocardial failure and death in the operating room. COMMENT The variety of unusual congenital lesions resulting in mitral regurgitation makes it possible to classify patients into two principal groups. The first group includes patients whose mitral regurgitation results from a clearly recognizable congenital defect primarily involving the valve. Anomalies in valve development result in cleft, scalloped, perforated, or rudimentary s and may be special forms of endocardial cushion defects. The correct diagnosis of an isolated cleft is rarely established before operation. From a hemodynamic standpoint, single clefts when properly suspended by chordae tendineae may be insignificant for a long time. It is therefore not surprising that 3 of our patients were older adults. When the cleft occurs in combination with an ostium secundum type of atrial septa1 defect, patients generally are misdiagnosed before operation as having incomplete atrioventricular canals, although only 1 of the patients clearly had a negative axis in the electrocardiogram. In patients with Marfan s syndrome, direct involvement of the mitral valve and its chordae by the characteristic mucopolysaccharide deposits may result in redundant s, dilated annulus, or ruptured chordae tendineae. Operative treatment may be successful, but the ultimate prognosis in these patients is poor because of widespread involvement of connective tissue. The second group of patients consists of those with mitral insufficiency associated with a congenital cardiac defect that could explain the valve pathology. For example, severe coarctation with constant pressure overload of the left ventricle may result in mitral insufficiency through dilation of the annulus or fibrosis of the s. This was the mechanism of mitral regurgitation in 2 of our 3 patients with coarctation. The third patient, however, had primary congenital defects of the mitral valve. The developmental mechanism of endocardial fibroelastosis remains obscure. It may be a reaction to chronically increased intracardiac tension, as outlined by Black-Schaffer [23, or secondary to viral myocarditis [S]. Its combination with mitral insufficiency seems to be common. Moller and colleagues [12] described a structural anomaly of the mitral valve in all their 47 reported patients with endocardial fibroelastosis. Of interest is the fact that 2 of our patients with coarctation also had 456 THE ANNALS OF THORACIC SURGERY

8 Congenital Mitral Insufficiency some degree of endocardial fibroelastosis, which indicates that a relationship may exist between the two entities and supports the theory that endocardial fibroelastosis may result from constant pressure overload. The occurrence of mitral insufficiency with an anomalous left coronary artery arising from the pulmonary artery is well known and results from fibrosis of the posterior papillary muscle [13]. This produces papillary muscle dysfunction and elongation of the chordae. Dilatation of the mitral annulus may also be present. Children with general enlargement of the heart and a murmur of mitral insufficiency should be suspected of having anomalous origin of the left coronary artery. New techniques in correction of the anomalous coronary artery origin with the aid of an autologous vein bypass graft give gratifying results, and mitral insufficiency may not need surgical repair [5]. In our series of 6 patients with this entity, only 1 required simultaneous surgical correction of the valve. This was effected with an annuloplasty. The operative approach is the same whether a patient belongs to the first or second group described above. Plastic repair should be considered in each case. A cleft may be closed with interrupted sutures. If an anomalous chorda is limiting mobility of the, it should be divided, provided that this would not result in a flail. Mitral annuloplasty is still justified and advocated in surgical treatment of congenital mitral insufficiency in some patients. If s are severely deformed, the mitral valve should be replaced. Low-profile disc prostheses are ideal in children, since protrusion of a cage into the left ventricle is minimal and there is less tendency for obstruction of the outflow tract and irritation of the septum by the struts [3]. The new Wada-Cutter tilting-disc prosthesis eliminates these hazards completely by virtue of its low profile and lack of struts [ll]. Since the mitral annulus is generally dilated, mitral valve replacement is possible even in young children. Small adult-sized prostheses can be used. A significant difference in operative risk exists between the two groups of patients with mitral regurgitation. While primary congenital mitral insufficiency was associated in our series with an early operative mortality of 9% and no late deaths, the second group had an early mortality of 57% and 1 late death (Table 3). The type of operation can- TABLE 3. DEATHS IN CONGENITAL MITRAL INSUFFICIENCY No. of Type of Lesion Patients Early Deaths Late Deaths Total Primary congenital mitral insufficiency 11 1(9%) 0 1(9%) Mitral insufficiency associated with other 7 4 (57%) 1 5 (71%) congenital lesions VOL. 10, NO. 5, NOVEMBER,

9 MESSMER, HALLMAN, AND COOI.EY not be responsible for the difference since it was similar in both groups. Age may be partially responsible. Patients with primary congenital mitral insufficiency are generally operated on later in their childhood or as adults, while patients with mitral insufficiency associated with some major congenital cardiovascular lesion usually require operation early in childhood. The most important difference, however, is the deleterious effect that the major associated cardiovascular lesion has on the myocardium. In view of this marked difference in prognosis, indications for mitral valve operation should be considered with caution in patients with mitral regurgitation associated with some major congenital cardiovascular anomaly. SUMMARY During the period between 1961 and 1969, 18 patients (15 children and 3 adults) underwent.operations for congenital mitral insufficiency not associated with partial or total atrioventricular canal. The patients were classified into two groups: (1) patients with primary congenital mitral insufficiency (cleft or scalloped s, Marfan s syndrome); and (2) patients with mitral insufficiency associated with coarctation, endocardial fibroelastosis, and anomalous origin of the left coronary artery from the pulmonary artery. Plastic repair was possible in 8 patients, and mitral valve replacement was required in 10. Early mortality was significantly higher for patients in the second group (57%) than in the first (9%), primarily because of the severity of the associated major cardiovascular anomalies in the second group. Patients with associated major congenital anomalies should be selected for mitral valve operation with caution. REFERENCES 1. Berghius, J., Kirklin, J. W., Edwards, J. E., and Titus, J. L. The surgical anatomy of isolated congenital mitral insufficiency. J. Thorac. Cardiovasc. Surg. 47:791, Black-Schaffer, B. Infantile endocardia1 fibroelastosis: A suggested etiology. A.M.A. Arch. Path. 63:281, Bloodwell, R. D., Hallman, G. L., McNamara, D. G., and Cooley, D. A. Cardiac valve replacement for congenital mitral valvular disease in children. J. Pediat. Szwg. 4:9, Cachin, J. C., Himbert, J., and Lenegre, J. Ostium secundum et insuffisance mitrale. Arch. Mal. Coeur 60:989, 1637, Cooley, D. A., Hallman, G. L., and Bloodwell, R. D. Definitive surgical treatment of anomalous origin of left coronary artery from pulmonary artery: Indications and results. J. Thorac. Cardiovasc. Surg. 52:798, Creech, O., Jr., Ledbetter, M. K., and Reemtsma, K. Congenital mitral insufficiency with cleft posterior. Circulation 25:390, Edwards, J. E., and Burchelle, H. B. Pathologic anatomy of mitral insufficiency. Proc. Staff. Meet. Mayo Clin. 33:497, THE ANNALS OF THORACIC SURGERY

10 Congenilal Mitral Znsiificiency 8. Flege, J. B., Vlad, P., and Ehrenhaft, J. L. Congenital mitral incompetence. J. Thorac. Cardiovasc. Surg. 53: 138, Fruhling, L., Korn, R., Lavillaureix, J., Surjur, A., and Fousereau, S. La myo-endocardite chronique fibro-elastique du nouveau-nc et du nournsson (fibro-tlastose). Ann. Anat. Path. (Paris) 7:227, Gopinathan, K., Esquerra, O., and Kozam, R. L. Congenital mitral regurgitation: Report of two cases. Amer. J. Cardiol. 24:241, Hallman, G. L., Messmer, B. J., Elkadi, A., Von der Emde, J., and Cooley, D. A. Clinical experience with the Wada-Cutter cardiac valve prosthesis. Ann, Thorac. Surg. 10:9, Moller, J. H., Lucas, R. V., Jr., Adams, P., Jr., Anderson, R. C., Jorgens, J., and Edwards, J. E. Endocardia1 fibroelastosis: A clinical and anatomic study of 47 patients with emphasis on its relationship to mitral insufficiency. Circulation 30:759, Noren, G. R., Raghib, G., Moller, J. H., Amplate, K., Adams, P., Jr., and Edwards, J. E. Anomalous origin of the left coronary artery from the pulmonary trunk with special reference to the occurrence of mitral insufficiency. Circulation 30: 171, Raglib, G., Jue, K. L., Anderson, R. C., and Edwards, J. E. Marfan s syndrome with mitral insufficiency. Amer. J. Cardiol. 16: 127, Sanchez, P. A., Kerth, W. J., Hill, J. D., and Gerbode, F. Surgical correction of congenital mitral insufficiency. Dis. Chest 55:395, Segal, B., Kasparian, H., and Likoff, W. Mitral regurgitation in a patient with Marfan syndrome. Dis. Chest 41:451, Simpson, J. W., Nora, J. J., and McNamara, D. G. Marfan s syndrome and mitral valve disease: Acute surgical emergencies. Amer. Heart J. 77:96, Sugg, W. L., and Fox, L. M. Congenital mitral insufficiency and secundum ASD. Vasc. Szirg. 1:205, DISCUSSION DR. WILLIAM NEVILLE (Hines, Ill.): I would like to report on 10 patients with congenital mitral insufficiency. Five of these have had valvuloplasty and have been followed from two to ten years. They have all done well except for 1 girl, who needed a valve replacement six years after an annular plication. Five others have had valve replacements, and there has been 1 death due to disruption of the prosthesis. The valve replacements were performed by my colleague Dr. Milton Weinberg of Chicago. I think all of us in this audience would agree that annular plication is a reasonable operation. It is a good procedure in children and even in adults with a dilated annulus. It is no good, however, in patients with valve deficiency. One individual had a massive heart with a marked decrease in the size of the cardiac silhouette some six years after an annular plication. Another individual we encountered two years ago had a congenital cleft in the mitral valve and an atrial secundum defect. We simply closed the cleft with sutures reinforced with Teflon pledgets and repaired the atrial septa1 defect. He has done exceedingly well. As far as valve replacements in children are concerned, Dr. Weinberg has operated on 16 patients to date. Five have been in the congenital mitral insufficiency group. One of his patients, who has a StamEdwards valve, is asymptomatic some four years following operation. This patient had a massive heart, and valve replacement was done only following an unsuccessful attempt at annular plication. We had one devastating complication related to a prosthetic valve. A Daggett valve completely disrupted approximately a year after its insertion. I think all of us in the audience would agree that valvuloplasty is certainly the procedure of choice when it can be expeditiously performed. In a certain number of children this is impossible, however, and one must use a prosthesis. VOL. 10, NO. 5, NOVEMBER,

11 MESSMER, HALLMAN, AND COOLEY DR. ERNEST HAWS (Fresno, Calif.): We have experience with 2 patients, both young infants. In both, medical management failed to control congestive heart failure; both demonstrated pulmonary congestion and bronchial compression from a giant left atrium. The first patient, a 16-month-old boy, survived mitral valvuloplasty and showed considerable improvement. Previously he had undergone resection for coarctation. The other patient was a 4M-month-old, 10%-pound girl who required intubation and total ventilatory support the day prior to operation. Cardiac massage was necessary just before bypass. The mitral insufficiency was an isolated lesion, but the valve was totally deficient. A No. 00 Starr-Edwards prosthesis was inserted, having an orifice of 1% sq. cm. (6120 series). The patient made an uneventful recovery with improvement clinically and on chest roentgenogram and electrocardiogram, going from below the third up to the fortieth weight percentile. There has been no arrhythmia as the left ventricle decreased in size. Coumadin was used for anticoagulation, with venipuncture prothrombin time control. There was no bleeding, hematoma, embolus, or evidence of clotting on the valve. Thirteen and one-half months ostoperatively this patient remains asymptomatic and appears to be a normal, Realthy girl. Our experience with this patient supports Dr. Messmer s findings that there is probably no age limit to valve replacement provided the heart is of sufficient size to accommodate the prosthesis. DR. IVAN A. MAY (Oakland, Calif.): At Children s Hospital in Oakland we corrected isolated mitral insufficiency due to the connective tissue defect of Marfan s syndrome in 2 teen-agers last March. Both had the angiographic findings published by Anderson, namely, mitral insufficiency due to prolapse of the mitral valve into the atrium and aortic sinus dilatation without aortic insufficiency. The redundant mitral valve prolapsed into the atrium because of the lengthened chordae tendineae. It has been described as a floppy valve that looks like hemorrhoids-and it does. In one of our patients the valve was insufficient only at the posterior end of the mural, and annuloplasty stopped the leak. The other patient s valve was unrepairable because the entire valve prolapsed. A No. 8 Smeloff-Cutter valve was used. No valve tissue was removed; it was all reefed up by a continuous overand-over suture to preserve all tissue available for support of the prosthesis. The valve was then sewed to this roll of tissue by interrupted mattress sutures. Additional stitches held all tissue out of the way of the ball. Preoperative and postoperative roentgenograms of the girl who had an annuloplasty showed marked diminution in cardiac size. At ten months after operation she is asymptomatic. The boy who had valve replacement was hospitalized for spontaneous pneumothorax. His original chest roentgenograms showed pneumothorax and an enlarged heart. Current roentgenograms show the heart to be much smaller. It has been ten months since he was operated on also, and he has gained 35 pounds, plays tennis, and goes hunting with his father. Thank you for the opportunity to present 2 patients with mitral insufficiency secondary to Marfan s syndrome who were helped by operation. DR. HALLMAN: I thank Drs. Neville, Haws, and May for their remarks confirming that annuloplasty and plastic suture of clefts can restore competence in patients with congenital lesions of the mitral valve and for confirming that valve replacement can be done successfully even in small infants. I would like to make the additional point, however, that low-profile valves are perhaps better suited for mitral replacement in small children. Some of the patients mentioned by the discussants had their valve replaced with caged-ball type valves. These protrude excessively into the ventricle, especially in small patients, and produce in some cases obstruction to the left ventricular outflow. Pressure exerted by the cage on the ventricular septum may be responsible for arrhythmias. Because of these 460 THE ANNALS OF THORACIC SIJRGERY

12 Congenital Mitral Znsuficiency considerations we changed to low-profile mitral prostheses. Finally, the valve size is not often an important consideration in patients with congenital mitral insufficiency-at least as far as the annulus is concerned. These valves tend to have a markedly dilated annulus and will accept an adult-sized mitral prosthesis. We urge caution in operating upon those patients who have mitral regurgitation in association with some severe congenital anomaly such as endocardia1 fibroelastosis, coarctation, or Marfan's syndrome, because the highest mortality is encountered in this group. VOL. 10, NO. 5, NOVEMBER,