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The Advantages of Open Mitral Commissurotomy for Mitral Stenosis
The Advantages of Open Mitral Commissurotomy for Mitral Stenosis* Alvaro Montoya, M.D.;·· Jaime Mulet, M.D.;t Roque Pifarre, M.D., F.C.C.P.;; John M. Moran, M.D., F.C.C.P.;§ and Henry ]. Sullivan, M.D.··
Mitral commissurotomy is the treatment of choice for
for it who required valvular replacement. Twenty-five patients had a left amal thrombus. Two patients died, one from aortic dissection and the other from acute infarction in the perioperative period. ~mety-eight patienM are NYHA dass 1 or 2 at present. Two· patients required valvular replacement following the commissurotomy. The low mobidity and mortality with exceDent long-term results support our contention that OpeD mitral co........ sorotomy is the treatment of choice for mitral stenosis.
Refinement of the prosthetic valve and improvements in the perioperative care of the patient undergoing mitral valvular replacement have resulted in better early and late survival, but complica-
open inspection of the valve, followed by the operation indicated. With the development of extracorporeal circulation and the safety reached by its new advances in technique, open valvulotomy has become the treatment of choice for the stenosed rheumatic mitral valve, with the same or better results than those obtained by the almost abandoned closed technique. Open mitral commissurotomy has become the treatment of choice for mitral valvular stenosis at Loyola University Medical Center, Maywood, Ill. The analysis of our early and late results and some thoughts concerning the closed method are presented.
mitral stenosis. If this is not feasible, replacement of the valve becomes necessary. Open commissurotomy has been performed at Loyola University Medical Center, Maywood, OJ, in 105 patients since 1970. The mean age was 45 yean. ]be 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 editorial comment, see page 112
tions related to these valvular substitutes continue to adversely affect the long-term results. Palliative or reconstructive operations that preserve the mitral valvular function for as long as possible are preferred, with prosthetic replacement reserved for unsalvageable valves. This concept may change as better prosthetic materials and designs are made available, but at the present time, even with the advent of the heterografts, early valvular replacement carries the disadvantage of uncertain longterm durability, a variable incidence of hemolysis and thromboembolism, subacute bacterial endocarditis, residual gradients, and perivalvular leaks.1-8 Structural architecture and pliability of the cusps of the stenosed mitral valve, the condition of the subvalvular apparatus, and the degree of incompetence are factors properly assessed only by the °From the Department of Surgery, Loyola University Medical Center, Maywood, and the Cardiopulmonary Surgery Section, Veterans Administration Hospital, Hines, Ill. Presented at the 43rd Annual Meeting, American College of Chest Physicians, Nov. 1, 1977, Las Vegas. ••Assistant Professor of Surgery. t Assistant Professor of Surgery, Barcelona Medical School, Barcelona, Spain. tprofessor of Surgery and Chief, Cardiopulmonary Surgery Section. §Associate Professor of Surgery. Manuscript received March 15; revision accepted July 26. Reprint requests: Dr. Pifarre, 2160 South First Avenue, Maywood, IUinois 60153
CHEST, 75: 2, FEBRUARY, 1979
MATERIALS AND METHODS
Patients
Three hundred and fifty patients underwent mitral valvular surgery alone or combined with other procedures between January 1970 and December 1976 at Loyola University Medical Center. One hundred and forty-seven patients were thought to be amenable for open mitral commissurotomy, and they were scheduled as such. Forty-two (28 percent) of those required mitral valvular replacement, leaving 105 patients suitable for our study. Eighty-five patients (81 percent) were women, and 20 (19 percent) were men. The patients ranged in age from 24 to 67 years, with 59 (56 percent) of them being age 40 to 60 years. Ninety-two patients (88 percent) underwent surgery for symptoms of congestive heart failure. Three patients (3 percent) had significant pain in the chest as a main symptom. Six (6 percent) initially had peripheral arterial emboli. Hemoptysis was the only symptom in three patients ( 3 percent). Irregular rhythm and palpitations were the main complaint of one of the patients. According to the New York Heart Association's (NYHA)
OPEN MITRAL COMMISSUROTOMY FOR MITRAL mNOSIS 131
classification, the distribution of patients before surgery was as follows: class 1, ten patients (10 percent); class 2, 27 patients (26 percent); class 3, 63 patients (60 percent); and class 4, five patients (5 percent). The chest x-ray film obtained on admission revealed left atrial enlargement in 69 patients. The preoperative electrocardiogram demonstrated sinus rhythm in 51 patients (49 percent) and atrial fibrillation in the remainder. All of the patients underwent cardiac catheterization. Eleven patients were found to have calcification of the valve. Five had significant coronary arterial disease. Ten had aortic valvular disease, and six had tricuspid insufficiency. The mean gradient across the mitral valve was 15.3 mm Hg, and the mean mitral valvular area was 1.1 sq CID. Seven patients underwent surgery from 3 to 15 years following closed mitral commissurotomy. Operation
Open mitral commissurotomy was performed following the standard technique previously described by different authors. Approach via a midstemotomy was chosen, and the mitral valve was exposed through a left atriotomy posterior to the interatrial groove. The commissures were opened sharply as wide as possible without producing insufficiency, obtaining a maximal diameter of the orifice between 3 and 4 em. SubvaIvular fusion was also relieved, when indicated, by sharp dissection; debridement of calcium in the valve and removal of the left atrial thrombus (if present) were done at the same time.
REsULTS
Eighty-five patients (81 percent) underwent open mitral commissurotomy alone. Twenty patients (19 percent) had simultaneous procedures. Tricuspid valvuloplasty was the most common (performed in six patients), followed by aortic valvular replacement (done in five patients). The other simultaneous procedures and the number of each were as follows: aortic valvuloplasty, three; aortocoronary venous graft bypasses, three; left internal mammary arterial implant, one; aortic valvular replacement (left anterior descending coronary arterial bypass and left ventricular aneurysmal plication), one; aortic valvular commissurotomy, one; and bronchoscopic examination and biopsy of left lung, one. Twenty-eight patients (27 percent) had additional valvuloplastic procedures performed at the time of open mitral commissurotomy. Of these, 19 had debridement of calcium from the leaflets. Thirtyone required correction of valvular insufficiency present before or produced during the operation, and 24 had relief of subvalvular fusion by incision through the scarred chordae down to the papillary muscle. A left atrial thrombus was removed in 25 patients (24 percent) . A history of preoperative systemic embolism was obtained in 19 patients (18 percent), with most of them being cerebral. Six (32 percent) of these 19 patients had a left atrial thrombus at the time of surgery. Nineteen patients (18 percent) without a
132 MONTOYA ET AL
history of preoperative embolism had a left atrial thrombus. The hearts of 21 (84 percent) of the 25 patients with left atrial thrombus were in atrial fibrillation, and 13 patients (68 percent) with preoperative embolism had this cardiac rhythm. Four (9 percent) of the 45 patients whose hearts were in sinus rhythm and who had no history of preoperative embolism were found to have a left atrial thrombus at the time of surgery (Table 1 ). There were two fatalities (2 percent) during hospitalization. Two days following open mitral commissurotomy alone, one patient died from sudden hemorrhage caused by a hypertensive crisis and rupture of the aortic wall at the venting site. The second fatality occurred 29 days following open mitral valvotomy and left internal mammary arterial implantation for coronary arterial disease. The cause of death was a massive myocardial infarction. There was one late death (1 percent). This patient underwent open mitral commissurotomy, followed by an aortocoronary bypass to the left anterior descending coronary artery six months later. Three and one-half years later, he died suddenly at home, presumably from an acute myocardial infarct. The mortality for the group with isolated open mitral commissurotomy was 1 percent (1/85). There were 22 early and late postoperative complications (21 percent). Four patients (4 percent) developed symptoms compatible with systemic emboli following surgery. Immediately after surgery, one patient developed a left-sided hemiparesis, which subsided in six months. This patient had had several embolic episodes before surgery, and his heart was in atrial fibrillation. At the time of surgery, no atrial thrombus was found. Three other patients developed central neurologic deficits at two, three, and four years following surgery. All of them recovered completely. At the time of the embolization, one patient's heart was in sinus rhythm, and the Table l--Cardiae Rhythm and Left Atria' Thromb... in Palie,," teitla and ";,lao.' Hu,o,.,. of Preoperali"e Emboliam·
Group and Cardiac Rhythm
Left Atrial Thrombus
No Left Atrial Thrombus
4
41
No preoperative embolism Sinus rhythm Atrial fibrillation
15 19
Totalfor~oup
History of preoperative embolism Sinus rhythm Atrial fibrillation Total for group
0 6 6
26
67
6 7 13
*Table values are numbers of patients.
CHEST, 75: 2, FEBRUARY, 1979
other patients had discontinued anticoagulant therapy without consulting their physician. Only one of these patients with atrial fibrillation had a history of preoperative systemic embolus. The patient who suffered myocardial infarction ultimately died and is included in the mortality during hospitalization. Two of these patients required reoperation for bleeding in the postoperative period. One of them bled suddenly and massively two days later and died. All of the 103 patients surviving the operation were followed-up for an average of 51 months by the cardiology staff at our institution or by the referring physician, with whom close contact was maintained. One-third of the patients had auscultatory findings compatible with minimal residual mitral stenosis or regurgitation ( or both) . One patient underwent a second open mitral commissurotomy. Two (2 percent) of the 103 patients subsequently required valvular replacement. In one patient the valve was replaced one week following commissurotomy, when severe regurgitation suddenly occurred. The other patient underwent mitral valvular replacement four years later for progressive symptoms of mitral insufficiency. Functional improvement based on the NYHA classification is shown in Table 2 for the 103 living patients. Sixty-three patients (60 percent) were in class 3 at the time of surgery. After surgery, 60 patients (58 percent) were in class 1. Four patients (4 percent) were in class 3 and none in class 4 after surgery. DISCUSSION
Artificial valves have not yet reached the point of perfection to justify early valvular replacement. Beside the risk of the operation, which is considerably higher than that of conservative mitral valvular surgery, prosthetic mitral valves add the risk of late complications such as thromboembolism, malfunction of the prostheses, and infection, the most common. 1-8 The introduction of porcine heterograft prostheses promises a better outlook for the patients requiring mitral valvular replacement. The incidences of Table 2-Funclionallmprovemen, in 105 Paden'. Undergoing Open Mitral Commi••uro'omy*
Before Surgery
After Surgery
Class 1
10 (10)
60 (58)
Class 2
27 (26)
38 (37)
Class 3
63 (60)
4 (4)
Class 4
5 (5)
NYHA Class
0
*Table values are numbers of patients; numbers within parentheses are percents.
CHEST, 75: 2, FEBRUARY, 1979
thromboembolism, perioperative and late deaths, and the residual gradient across the prosthesis make this porcine valve still less than ideal. 9•1o Preservation of mitral valvular function through an adequate palliative operation is still the best treatment for mitral stenosis. The first digital mitral commissuorotomy was performed in 1925 by Souttar, but it was not until 1948 when Harken et alii and 1949 when Bailey" applied the procedure on a large scale, causing a breakthrough in the treatment of mitral stenosis. Since then, many patients have benefited from this operation." Recent achievements in physiology and technology have allowed the performance of mitral valvotomy under direct vision by means of cardiopulmonary bypass. In recent years, it has become apparent that the risk of cardiopulmonary bypass in itself is not significantly different from the risk of anesthesia and thoracotomy. The ideal surgical approach to mitral stenosis was well delineated by Nichols et al,14 according to the following objectives: (1) accurate incision of the fused commissural edges to their full extent; ( 2 ) relief of subvalvular fusion by incision through scarred chordae down to papillary muscle; (3) evacuation of all atrial clots; (4) removal (without affecting the integrity of the valvular cusps) of calcific deposits that limit the valvular action or provide an embolic potential; (5) correction of any valvular insufficiency present before or produced during the operation; and (6) total valvular replacement when valvuloplasty cannot be accomplished. Since 1970 in our institution, 147 patients underwent surgery for mitral stenosis. Forty-two (29 percent) of them had severe enough disease that valvular replacement had to be performed. There is a possibility that the open approach tends to increase the number of valves replaced. Our figure of 28 percent compares favorably with the series reported by Roe et aI,15 when 44 percent of the valves were replaced, but is higher than the 8 percent reported by Grantham et al 16 in patients undergoing closed valvotomies. Selection of patients could explain the discrepancy. With our technique, only the presence of significant regurgitation was considered a preoperative indication of valvular replacement. Our mortality of 1 percent for the group with isolated open mitral commissurotomy is in the range of other reported series.14.1S.17-20 This figure is well below the in-hospital mortality for closed commissurotomy, which fluctuates between 3 and 17 percent.ll.16.21-24 An important point to mention is that 28 patients had more than a simple valvulotomy, such as debridement of calcium, correction of
OPEN MITRAL COMMISSUROTOMY FOR MITRAL STENOSIS 133
insufficiency, and relief of subvalvular fusion, procedures not feasible with the closed technique. It is remarkable that our figure is very similar to the one reported by Mullin et al. 19 Mitral stenosis, particularly when accompanied by atrial fibrillation, is the ideal setup for the formation of a left atrial thrombus and the occurrence of systemic embolism. Detection of atrial clots is crucial when the closed approach is used; but unfortunately, it is nearly impossible to diagnose them before surgery." There is not a direct correlation between preoperative systemic embolism and the presence of left atrial clots at the time of surgery. We encountered a left atrial thrombus in 19 patients with no history of embolus, similar to the findings reported by Roe et al,15 Mullin et al,19 and Aaron and Lower. 20 Furthermore, in our series, four of the patients with left atrial thrombus had normal sinus rhythm and no history of systemic embolism. Atrial fibrillation predisposes to the formation of a left atrial thrombus, but in 59 of our patients with atrial fibrillation, only 21 had an atrial thrombus. Therefore, just the presence of mitral stenosis may account for the formation of a left atrial thrombus, and such thrombi have to be suspected in any patient with this disease, regardless of history or cardiac rhythm. The presence of a clot in the left atrium is always a threat in closed commissurotomy, raising the mortality and the incidence of perioperative embolism to prohibitive levels." The incidence of perioperative embolism could be reduced to the minimum using the open approach, if careful attention were paid to the techniques of eliminating intracardiac clots and air. Only one patient (1 percent) developed left-sided hemiparesis immediately following surgery. Late embolization is probably related to the adequacy of the valvotomy or the recurrence of the stenosis (or both). Anticoagulative therapy could avoid some of these late embolisms.P but the lack of a reliable indicator of the patients at risk and the danger of continuous anticoagulation therapy make this practice inapplicable. Mitral valvotomy is palliative, rather than a curative treatment for mitral stenosis. Of the 103 surviving patients who were followed-up for periods ranging from five months to seven years (mean, 51 months), one required reoperation for stenosis, although it is conceivable that more patients will require repeated open mitral commissurotomy in the future. 4.26 Improvement in the functional classification of the surviving patients is similar to that observed in previous series. It has been known for many years that
134 MONTOYA ET AL
these patients improve dramatically when the stenosis is relieved. As pointed out by Mullin et al,19 enlarging the mitral orifice to an area of 1.5 or 2 sq em is enough to diminish the symptoms, placing the patient in a better classification. It is because of that particular point that functional result cannot be used to evaluate the superiority of either the open or closed technique. With the technologic advances capable of reducing the risk of cardiopulmonary bypass to levels similar to those of a simple thoracotomy, it seems logical to make use of its advantages in order to perform a precise unhurried operation under direct vision, such as, open valvotomy for mitral valvular stenosis. REFERENCES
1 Oury JH, Peterson KL, Folkerth TL, et al: Mitral valve replacement versus reconstruction. J Thorac Cardiovasc Surg 75:825-835, 1977 2 Kastor JA, Akbarian M, Buckley MJ, et aI: Paravalvular leaks and hemolytic anemia following insertion of StarrEdwards aortic and mitral valves. J Thorac Cardiovasc Surg 56:279-288, 1968 3 Kouchoukos NT: Problems in mitral valve replacement. Adv Cardiovasc Surg 00:205, 1973 4 Bonchek LI, Anderson KP, Starr A: Mitral valve replacement with cloth covered composite seat prosthesis. J Thorac Cardiovasc Surg 67:93-109, 1974 5 Montoya A, Sullivan HJ, Pifarre R: Disc variance: A potentially lethal complication of the Beall valve prosthesis. J Thorac Cardiovasc Surg 71:904-906, 1976 6 Bjork YO, Book K, Holmgren A: The Bjork Shiley mitral valve prosthesis. Ann Thorac Surg 18:379-390, 1974 7 Isom OW, Williams CD, Falk EA, et al: Long term evaluation of cloth covered metallic ball prostheses. J Thorac Cardiovasc Surg 64:354-367, 1972 8 Wukasch DC, Sandiford FM, Reul GJ, et al: Complications of cloth covered prosthetic valves: Results with a new mitral prosthesis. J Thorac Cardiovasc Surg 69: 107-' 116, 1975 9 Salomon NW, Stinson EB, Griepp RB, et al: Mitral valve replacement: Long term evaluation of prosthesis-related mortality and morbidity. Circulation 56 (suppl 2): 11-9411-101, 1977 10 Luire AJ, Miller RR, Maxwell KS, et al: Hemodynamic assessment of the glutaraldehyde-preserved porcine hetrograft in the aortic and mitral positions. Circulation (suppI2) :11-104-11-110,1977 11 Harken DE, Ellis LB, Ware PF, et al: The surgical treatment of mitral stenosis. N Engl J Med 239:801-809,
1948
12 Bailey CP: The surgical treatment of mitral stenosis (mitral commissurotomy). Dis Chest 15: 377-397, 1949 13 Ellis LB, Sinch JB, Morales DD, et al: Fifteen to twenty year study of 1000 patients undergoing closed mitral valvuloplasty. Circulation 48: 357 -364, 1973 14 Nichols HT, Blanco G, Morse DP, et al: Open mitral commissurotomy. JAMA 182:148-150,1962 15 Roe BB, Edmunds LH, Fishman NH, et al: Open mitral valvulotomy. Ann Thorac Surg 12:483-491, 1971 16 Grantham RN, Daggett WM, Cosimi AB, et al: Transventricular mitral valvulotomy. Circulation 50 (supple 2) :1149-11-50, 11-200-11-211, 1974
CHEST, 75: 2, FEBRUARY, 1979
17 Gerami S, Messmer BJ, Hallman GL, et al: Open mitral commissurotomy. J Thorac Cardiovasc Surg 62:366-370, 1971 18 Finnegan JO, Gray DC, MacVaugh HL, et al: The open approach to mitral commissurotomy. J Thorac Cardiovasc Surg 67:75-82,1974 19 Mullin JJ, Engleman RM, Isom OW, et al: Experience with open mitral commissurotomy in 100 consecutive patients. Surgery 76:974-982, 1974 20 Aaron BL, Lower RR: Advantages of open mitral commissurotomy using a triple orifice technique. Ann Thorac Surg 19:654-658, 1975 21 Fraser K, Turner MA, Sugden BA: Closed mitral valvotomy. Br Med J 2:352-353, 1976 22 Ellis LB, Benson H, Harken DE: The effect of age and
23
24
25 26
other factors on early and late results following closed mitral valvuloplasty. Am Heart J 75:743-751, 1968 Sealy WC, Young WG: Acquired mitral stenosis: An inquiry into its progressive and recurrent nature and the influence of preventive measures and surgery on its natural history. Ann Thorac Surg 1:244-258, 1965 Hanlon CR, Kaiser GC, Mudd JG, et al: Closed mitral commissurotomy for mitral stenosis. Ann Surg 167 :796BOO, 1968 Pelletier C, Bizri S, Cossette R, et al: Left atrial thrombosis complicating mitral stenosis: Results of surgical treatment. Can J Surg 20:101-106, 1977 Housman LB, Bonchek L, Lambert L, et al: Prognosis of patients after open mitral commissurotomy. J Thorac Cardiovasc Surg 73:742-745, 1977
15th Annual Arizona Chest Symposium The Doubletree Inn, Tucson, will be the site of the 15th Annual Arizona Chest Symposium, April 6-8. Sponsors are the Tucson Medical Center (Pulmonary Section), University of Arizona College of Medicine (Division of Respiratory Sciences). For information, contact Linda Alpert, R.N., Tucson Medical Center, PO Box 6067, Tucson 85733.
Update on Cardiology Boston University Medical Center will present the course, (CAn Update on Cardiology" April 5-10 at the Sonesta Beach Hotel, Bermuda, For information, contact Ms. Donna Marcy, Department of Continuing Medical Education, Boston University School of Medicine, 80 East Concord, Boston 02118.
CHEST, 75: 2, FEBRUARY, 1979
OPEN MITRAL COMMISSUROTOMY FOR MITRAL STENOSIS 135
Mitral commissurotomy is the treatment of choice for
for it who required valvular replacement. Twenty-five patients had a left amal thrombus. Two patients died, one from aortic dissection and the other from acute infarction in the perioperative period. ~mety-eight patienM are NYHA dass 1 or 2 at present. Two· patients required valvular replacement following the commissurotomy. The low mobidity and mortality with exceDent long-term results support our contention that OpeD mitral co........ sorotomy is the treatment of choice for mitral stenosis.
Refinement of the prosthetic valve and improvements in the perioperative care of the patient undergoing mitral valvular replacement have resulted in better early and late survival, but complica-
open inspection of the valve, followed by the operation indicated. With the development of extracorporeal circulation and the safety reached by its new advances in technique, open valvulotomy has become the treatment of choice for the stenosed rheumatic mitral valve, with the same or better results than those obtained by the almost abandoned closed technique. Open mitral commissurotomy has become the treatment of choice for mitral valvular stenosis at Loyola University Medical Center, Maywood, Ill. The analysis of our early and late results and some thoughts concerning the closed method are presented.
mitral stenosis. If this is not feasible, replacement of the valve becomes necessary. Open commissurotomy has been performed at Loyola University Medical Center, Maywood, OJ, in 105 patients since 1970. The mean age was 45 yean. ]be 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 editorial comment, see page 112
tions related to these valvular substitutes continue to adversely affect the long-term results. Palliative or reconstructive operations that preserve the mitral valvular function for as long as possible are preferred, with prosthetic replacement reserved for unsalvageable valves. This concept may change as better prosthetic materials and designs are made available, but at the present time, even with the advent of the heterografts, early valvular replacement carries the disadvantage of uncertain longterm durability, a variable incidence of hemolysis and thromboembolism, subacute bacterial endocarditis, residual gradients, and perivalvular leaks.1-8 Structural architecture and pliability of the cusps of the stenosed mitral valve, the condition of the subvalvular apparatus, and the degree of incompetence are factors properly assessed only by the °From the Department of Surgery, Loyola University Medical Center, Maywood, and the Cardiopulmonary Surgery Section, Veterans Administration Hospital, Hines, Ill. Presented at the 43rd Annual Meeting, American College of Chest Physicians, Nov. 1, 1977, Las Vegas. ••Assistant Professor of Surgery. t Assistant Professor of Surgery, Barcelona Medical School, Barcelona, Spain. tprofessor of Surgery and Chief, Cardiopulmonary Surgery Section. §Associate Professor of Surgery. Manuscript received March 15; revision accepted July 26. Reprint requests: Dr. Pifarre, 2160 South First Avenue, Maywood, IUinois 60153
CHEST, 75: 2, FEBRUARY, 1979
MATERIALS AND METHODS
Patients
Three hundred and fifty patients underwent mitral valvular surgery alone or combined with other procedures between January 1970 and December 1976 at Loyola University Medical Center. One hundred and forty-seven patients were thought to be amenable for open mitral commissurotomy, and they were scheduled as such. Forty-two (28 percent) of those required mitral valvular replacement, leaving 105 patients suitable for our study. Eighty-five patients (81 percent) were women, and 20 (19 percent) were men. The patients ranged in age from 24 to 67 years, with 59 (56 percent) of them being age 40 to 60 years. Ninety-two patients (88 percent) underwent surgery for symptoms of congestive heart failure. Three patients (3 percent) had significant pain in the chest as a main symptom. Six (6 percent) initially had peripheral arterial emboli. Hemoptysis was the only symptom in three patients ( 3 percent). Irregular rhythm and palpitations were the main complaint of one of the patients. According to the New York Heart Association's (NYHA)
OPEN MITRAL COMMISSUROTOMY FOR MITRAL mNOSIS 131
classification, the distribution of patients before surgery was as follows: class 1, ten patients (10 percent); class 2, 27 patients (26 percent); class 3, 63 patients (60 percent); and class 4, five patients (5 percent). The chest x-ray film obtained on admission revealed left atrial enlargement in 69 patients. The preoperative electrocardiogram demonstrated sinus rhythm in 51 patients (49 percent) and atrial fibrillation in the remainder. All of the patients underwent cardiac catheterization. Eleven patients were found to have calcification of the valve. Five had significant coronary arterial disease. Ten had aortic valvular disease, and six had tricuspid insufficiency. The mean gradient across the mitral valve was 15.3 mm Hg, and the mean mitral valvular area was 1.1 sq CID. Seven patients underwent surgery from 3 to 15 years following closed mitral commissurotomy. Operation
Open mitral commissurotomy was performed following the standard technique previously described by different authors. Approach via a midstemotomy was chosen, and the mitral valve was exposed through a left atriotomy posterior to the interatrial groove. The commissures were opened sharply as wide as possible without producing insufficiency, obtaining a maximal diameter of the orifice between 3 and 4 em. SubvaIvular fusion was also relieved, when indicated, by sharp dissection; debridement of calcium in the valve and removal of the left atrial thrombus (if present) were done at the same time.
REsULTS
Eighty-five patients (81 percent) underwent open mitral commissurotomy alone. Twenty patients (19 percent) had simultaneous procedures. Tricuspid valvuloplasty was the most common (performed in six patients), followed by aortic valvular replacement (done in five patients). The other simultaneous procedures and the number of each were as follows: aortic valvuloplasty, three; aortocoronary venous graft bypasses, three; left internal mammary arterial implant, one; aortic valvular replacement (left anterior descending coronary arterial bypass and left ventricular aneurysmal plication), one; aortic valvular commissurotomy, one; and bronchoscopic examination and biopsy of left lung, one. Twenty-eight patients (27 percent) had additional valvuloplastic procedures performed at the time of open mitral commissurotomy. Of these, 19 had debridement of calcium from the leaflets. Thirtyone required correction of valvular insufficiency present before or produced during the operation, and 24 had relief of subvalvular fusion by incision through the scarred chordae down to the papillary muscle. A left atrial thrombus was removed in 25 patients (24 percent) . A history of preoperative systemic embolism was obtained in 19 patients (18 percent), with most of them being cerebral. Six (32 percent) of these 19 patients had a left atrial thrombus at the time of surgery. Nineteen patients (18 percent) without a
132 MONTOYA ET AL
history of preoperative embolism had a left atrial thrombus. The hearts of 21 (84 percent) of the 25 patients with left atrial thrombus were in atrial fibrillation, and 13 patients (68 percent) with preoperative embolism had this cardiac rhythm. Four (9 percent) of the 45 patients whose hearts were in sinus rhythm and who had no history of preoperative embolism were found to have a left atrial thrombus at the time of surgery (Table 1 ). There were two fatalities (2 percent) during hospitalization. Two days following open mitral commissurotomy alone, one patient died from sudden hemorrhage caused by a hypertensive crisis and rupture of the aortic wall at the venting site. The second fatality occurred 29 days following open mitral valvotomy and left internal mammary arterial implantation for coronary arterial disease. The cause of death was a massive myocardial infarction. There was one late death (1 percent). This patient underwent open mitral commissurotomy, followed by an aortocoronary bypass to the left anterior descending coronary artery six months later. Three and one-half years later, he died suddenly at home, presumably from an acute myocardial infarct. The mortality for the group with isolated open mitral commissurotomy was 1 percent (1/85). There were 22 early and late postoperative complications (21 percent). Four patients (4 percent) developed symptoms compatible with systemic emboli following surgery. Immediately after surgery, one patient developed a left-sided hemiparesis, which subsided in six months. This patient had had several embolic episodes before surgery, and his heart was in atrial fibrillation. At the time of surgery, no atrial thrombus was found. Three other patients developed central neurologic deficits at two, three, and four years following surgery. All of them recovered completely. At the time of the embolization, one patient's heart was in sinus rhythm, and the Table l--Cardiae Rhythm and Left Atria' Thromb... in Palie,," teitla and ";,lao.' Hu,o,.,. of Preoperali"e Emboliam·
Group and Cardiac Rhythm
Left Atrial Thrombus
No Left Atrial Thrombus
4
41
No preoperative embolism Sinus rhythm Atrial fibrillation
15 19
Totalfor~oup
History of preoperative embolism Sinus rhythm Atrial fibrillation Total for group
0 6 6
26
67
6 7 13
*Table values are numbers of patients.
CHEST, 75: 2, FEBRUARY, 1979
other patients had discontinued anticoagulant therapy without consulting their physician. Only one of these patients with atrial fibrillation had a history of preoperative systemic embolus. The patient who suffered myocardial infarction ultimately died and is included in the mortality during hospitalization. Two of these patients required reoperation for bleeding in the postoperative period. One of them bled suddenly and massively two days later and died. All of the 103 patients surviving the operation were followed-up for an average of 51 months by the cardiology staff at our institution or by the referring physician, with whom close contact was maintained. One-third of the patients had auscultatory findings compatible with minimal residual mitral stenosis or regurgitation ( or both) . One patient underwent a second open mitral commissurotomy. Two (2 percent) of the 103 patients subsequently required valvular replacement. In one patient the valve was replaced one week following commissurotomy, when severe regurgitation suddenly occurred. The other patient underwent mitral valvular replacement four years later for progressive symptoms of mitral insufficiency. Functional improvement based on the NYHA classification is shown in Table 2 for the 103 living patients. Sixty-three patients (60 percent) were in class 3 at the time of surgery. After surgery, 60 patients (58 percent) were in class 1. Four patients (4 percent) were in class 3 and none in class 4 after surgery. DISCUSSION
Artificial valves have not yet reached the point of perfection to justify early valvular replacement. Beside the risk of the operation, which is considerably higher than that of conservative mitral valvular surgery, prosthetic mitral valves add the risk of late complications such as thromboembolism, malfunction of the prostheses, and infection, the most common. 1-8 The introduction of porcine heterograft prostheses promises a better outlook for the patients requiring mitral valvular replacement. The incidences of Table 2-Funclionallmprovemen, in 105 Paden'. Undergoing Open Mitral Commi••uro'omy*
Before Surgery
After Surgery
Class 1
10 (10)
60 (58)
Class 2
27 (26)
38 (37)
Class 3
63 (60)
4 (4)
Class 4
5 (5)
NYHA Class
0
*Table values are numbers of patients; numbers within parentheses are percents.
CHEST, 75: 2, FEBRUARY, 1979
thromboembolism, perioperative and late deaths, and the residual gradient across the prosthesis make this porcine valve still less than ideal. 9•1o Preservation of mitral valvular function through an adequate palliative operation is still the best treatment for mitral stenosis. The first digital mitral commissuorotomy was performed in 1925 by Souttar, but it was not until 1948 when Harken et alii and 1949 when Bailey" applied the procedure on a large scale, causing a breakthrough in the treatment of mitral stenosis. Since then, many patients have benefited from this operation." Recent achievements in physiology and technology have allowed the performance of mitral valvotomy under direct vision by means of cardiopulmonary bypass. In recent years, it has become apparent that the risk of cardiopulmonary bypass in itself is not significantly different from the risk of anesthesia and thoracotomy. The ideal surgical approach to mitral stenosis was well delineated by Nichols et al,14 according to the following objectives: (1) accurate incision of the fused commissural edges to their full extent; ( 2 ) relief of subvalvular fusion by incision through scarred chordae down to papillary muscle; (3) evacuation of all atrial clots; (4) removal (without affecting the integrity of the valvular cusps) of calcific deposits that limit the valvular action or provide an embolic potential; (5) correction of any valvular insufficiency present before or produced during the operation; and (6) total valvular replacement when valvuloplasty cannot be accomplished. Since 1970 in our institution, 147 patients underwent surgery for mitral stenosis. Forty-two (29 percent) of them had severe enough disease that valvular replacement had to be performed. There is a possibility that the open approach tends to increase the number of valves replaced. Our figure of 28 percent compares favorably with the series reported by Roe et aI,15 when 44 percent of the valves were replaced, but is higher than the 8 percent reported by Grantham et al 16 in patients undergoing closed valvotomies. Selection of patients could explain the discrepancy. With our technique, only the presence of significant regurgitation was considered a preoperative indication of valvular replacement. Our mortality of 1 percent for the group with isolated open mitral commissurotomy is in the range of other reported series.14.1S.17-20 This figure is well below the in-hospital mortality for closed commissurotomy, which fluctuates between 3 and 17 percent.ll.16.21-24 An important point to mention is that 28 patients had more than a simple valvulotomy, such as debridement of calcium, correction of
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insufficiency, and relief of subvalvular fusion, procedures not feasible with the closed technique. It is remarkable that our figure is very similar to the one reported by Mullin et al. 19 Mitral stenosis, particularly when accompanied by atrial fibrillation, is the ideal setup for the formation of a left atrial thrombus and the occurrence of systemic embolism. Detection of atrial clots is crucial when the closed approach is used; but unfortunately, it is nearly impossible to diagnose them before surgery." There is not a direct correlation between preoperative systemic embolism and the presence of left atrial clots at the time of surgery. We encountered a left atrial thrombus in 19 patients with no history of embolus, similar to the findings reported by Roe et al,15 Mullin et al,19 and Aaron and Lower. 20 Furthermore, in our series, four of the patients with left atrial thrombus had normal sinus rhythm and no history of systemic embolism. Atrial fibrillation predisposes to the formation of a left atrial thrombus, but in 59 of our patients with atrial fibrillation, only 21 had an atrial thrombus. Therefore, just the presence of mitral stenosis may account for the formation of a left atrial thrombus, and such thrombi have to be suspected in any patient with this disease, regardless of history or cardiac rhythm. The presence of a clot in the left atrium is always a threat in closed commissurotomy, raising the mortality and the incidence of perioperative embolism to prohibitive levels." The incidence of perioperative embolism could be reduced to the minimum using the open approach, if careful attention were paid to the techniques of eliminating intracardiac clots and air. Only one patient (1 percent) developed left-sided hemiparesis immediately following surgery. Late embolization is probably related to the adequacy of the valvotomy or the recurrence of the stenosis (or both). Anticoagulative therapy could avoid some of these late embolisms.P but the lack of a reliable indicator of the patients at risk and the danger of continuous anticoagulation therapy make this practice inapplicable. Mitral valvotomy is palliative, rather than a curative treatment for mitral stenosis. Of the 103 surviving patients who were followed-up for periods ranging from five months to seven years (mean, 51 months), one required reoperation for stenosis, although it is conceivable that more patients will require repeated open mitral commissurotomy in the future. 4.26 Improvement in the functional classification of the surviving patients is similar to that observed in previous series. It has been known for many years that
134 MONTOYA ET AL
these patients improve dramatically when the stenosis is relieved. As pointed out by Mullin et al,19 enlarging the mitral orifice to an area of 1.5 or 2 sq em is enough to diminish the symptoms, placing the patient in a better classification. It is because of that particular point that functional result cannot be used to evaluate the superiority of either the open or closed technique. With the technologic advances capable of reducing the risk of cardiopulmonary bypass to levels similar to those of a simple thoracotomy, it seems logical to make use of its advantages in order to perform a precise unhurried operation under direct vision, such as, open valvotomy for mitral valvular stenosis. REFERENCES
1 Oury JH, Peterson KL, Folkerth TL, et al: Mitral valve replacement versus reconstruction. J Thorac Cardiovasc Surg 75:825-835, 1977 2 Kastor JA, Akbarian M, Buckley MJ, et aI: Paravalvular leaks and hemolytic anemia following insertion of StarrEdwards aortic and mitral valves. J Thorac Cardiovasc Surg 56:279-288, 1968 3 Kouchoukos NT: Problems in mitral valve replacement. Adv Cardiovasc Surg 00:205, 1973 4 Bonchek LI, Anderson KP, Starr A: Mitral valve replacement with cloth covered composite seat prosthesis. J Thorac Cardiovasc Surg 67:93-109, 1974 5 Montoya A, Sullivan HJ, Pifarre R: Disc variance: A potentially lethal complication of the Beall valve prosthesis. J Thorac Cardiovasc Surg 71:904-906, 1976 6 Bjork YO, Book K, Holmgren A: The Bjork Shiley mitral valve prosthesis. Ann Thorac Surg 18:379-390, 1974 7 Isom OW, Williams CD, Falk EA, et al: Long term evaluation of cloth covered metallic ball prostheses. J Thorac Cardiovasc Surg 64:354-367, 1972 8 Wukasch DC, Sandiford FM, Reul GJ, et al: Complications of cloth covered prosthetic valves: Results with a new mitral prosthesis. J Thorac Cardiovasc Surg 69: 107-' 116, 1975 9 Salomon NW, Stinson EB, Griepp RB, et al: Mitral valve replacement: Long term evaluation of prosthesis-related mortality and morbidity. Circulation 56 (suppl 2): 11-9411-101, 1977 10 Luire AJ, Miller RR, Maxwell KS, et al: Hemodynamic assessment of the glutaraldehyde-preserved porcine hetrograft in the aortic and mitral positions. Circulation (suppI2) :11-104-11-110,1977 11 Harken DE, Ellis LB, Ware PF, et al: The surgical treatment of mitral stenosis. N Engl J Med 239:801-809,
1948
12 Bailey CP: The surgical treatment of mitral stenosis (mitral commissurotomy). Dis Chest 15: 377-397, 1949 13 Ellis LB, Sinch JB, Morales DD, et al: Fifteen to twenty year study of 1000 patients undergoing closed mitral valvuloplasty. Circulation 48: 357 -364, 1973 14 Nichols HT, Blanco G, Morse DP, et al: Open mitral commissurotomy. JAMA 182:148-150,1962 15 Roe BB, Edmunds LH, Fishman NH, et al: Open mitral valvulotomy. Ann Thorac Surg 12:483-491, 1971 16 Grantham RN, Daggett WM, Cosimi AB, et al: Transventricular mitral valvulotomy. Circulation 50 (supple 2) :1149-11-50, 11-200-11-211, 1974
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17 Gerami S, Messmer BJ, Hallman GL, et al: Open mitral commissurotomy. J Thorac Cardiovasc Surg 62:366-370, 1971 18 Finnegan JO, Gray DC, MacVaugh HL, et al: The open approach to mitral commissurotomy. J Thorac Cardiovasc Surg 67:75-82,1974 19 Mullin JJ, Engleman RM, Isom OW, et al: Experience with open mitral commissurotomy in 100 consecutive patients. Surgery 76:974-982, 1974 20 Aaron BL, Lower RR: Advantages of open mitral commissurotomy using a triple orifice technique. Ann Thorac Surg 19:654-658, 1975 21 Fraser K, Turner MA, Sugden BA: Closed mitral valvotomy. Br Med J 2:352-353, 1976 22 Ellis LB, Benson H, Harken DE: The effect of age and
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other factors on early and late results following closed mitral valvuloplasty. Am Heart J 75:743-751, 1968 Sealy WC, Young WG: Acquired mitral stenosis: An inquiry into its progressive and recurrent nature and the influence of preventive measures and surgery on its natural history. Ann Thorac Surg 1:244-258, 1965 Hanlon CR, Kaiser GC, Mudd JG, et al: Closed mitral commissurotomy for mitral stenosis. Ann Surg 167 :796BOO, 1968 Pelletier C, Bizri S, Cossette R, et al: Left atrial thrombosis complicating mitral stenosis: Results of surgical treatment. Can J Surg 20:101-106, 1977 Housman LB, Bonchek L, Lambert L, et al: Prognosis of patients after open mitral commissurotomy. J Thorac Cardiovasc Surg 73:742-745, 1977
15th Annual Arizona Chest Symposium The Doubletree Inn, Tucson, will be the site of the 15th Annual Arizona Chest Symposium, April 6-8. Sponsors are the Tucson Medical Center (Pulmonary Section), University of Arizona College of Medicine (Division of Respiratory Sciences). For information, contact Linda Alpert, R.N., Tucson Medical Center, PO Box 6067, Tucson 85733.
Update on Cardiology Boston University Medical Center will present the course, (CAn Update on Cardiology" April 5-10 at the Sonesta Beach Hotel, Bermuda, For information, contact Ms. Donna Marcy, Department of Continuing Medical Education, Boston University School of Medicine, 80 East Concord, Boston 02118.
CHEST, 75: 2, FEBRUARY, 1979
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