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Prosthetic valve reoperations
Prosthetic valve reoperations Factors influencing early and late survival Population characteristics and survival factors are presented for 89 reoperations (eight referrals) from 1,445 valve replacements performed over 17 years at the Columbia-Presbyterian Hospital. There were three basic categories of indications leading to reoperation: valve-related systemic disease (infection. embolism, hemolysis), valve-related insufficiency (paravalvular leak, ball variance, homograft retraction), and valve-related stenosis (thrombosis, pannus, homograft obstruction). The leading indication for reoperation among aortic, mitral, and double valves was systemic disease (43 of 83-52 percent); tricuspid reoperations were most frequently performed (five of six-83 percent) for valve-related stenosis. The over-all early mortality rate was 19 percent (17 of 89) and varied with the reoperative site, indication, and urgency. In general, survival was lower in atrioventricular than aortic prosthetic reoperations. High-risk reoperations (N = 37, mortality rate 43.2 percent) occurred in the presence of prosthetic infection or prosthetic stenosis. When reoperations were performed urgently in the high-risk group, the mortality rate increased to 67 percent (16 of 24). However, in the absence of infection or stenosis, regardless of the urgency of reoperation, the mortality rate was only two percent. Five-year survival rates for low-risk reoperations were-aortic 69 percent and mitral 55 percent. Morbidity parameters among survivors did not differ from initial valve replacements. It appears that prosthetic valve reoperations can be performed with risks equal to the original operation except in the presence of subacute prosthetic infection or end-stage prosthetic stenosis.
Donald C. Syracuse, M.D., Frederick O. Bowman, Jr., M.D., and James R. Maim, M.D., New York, N. Y.
Reoperation on prosthetic valves assumes greater importance as the population at risk increases' and the limited durability of prosthetic valves becomes apparent. 2-,'; To define the group of patients who undergo reoperation on prosthetic valves and the factors influencing early and late survival, we reviewed the experiences at the Columbia-Presbyterian Medical Center.
Methods A retrospective study was conducted on 89 reoperations performed on 83 adult patients from a total of 1,445 valve replacement operations from December, 1960, through July, 1977. Only adults who were reFrom the Thoracic and Cardiac Surgical Service, Department of Surgery, Columbia University College of Physicians and Surgeons, Presbyterian Hospital, New York, N.Y. 10032. Read at the Fourth Annual Meeting of The Samson Thoracic Surgical Society, Coronado, Calif., June 4-7, 1978. Address for reprints: Donald C. Syracuse, M.D., Thoracic and Cardiac Surgical Service, Department of Surgery, Presbyterian Hospital, 630 West 168 St., New York, N. Y. 10032.
346
operated upon for a prosthesis-related disorder were included. Reoperations were organized by the site of the prosthesis: aortic, mitral, tricuspid, or combination (aortic and mitral or mitral and tricuspid). There were no reoperations on patients having triple valve replacement and none which simultaneously involved prosthetic aortic and tricuspid valves. Three categories of prosthesis-related disorders were assigned: stenosis, insufficiency, and systemic disease. Indications for reoperation at each site were organized under these categories, subdivided by the specific disorder prompting reoperation, and designated as urgent or elective. All reoperations were considered as elective except those on moribund patients whose death was imminent. There was a minimum follow-up period of 6 months. Data were complete on all save five patients who were known to be long-term survivors but were subsequently lost to follow-up. Early and late mortality and morbidity rates reflected patient status through December, 1977. Five-year survival curves were generated on pa-
0022-5223/79/030346+09$00.90/0 © 1979 The C. V. Mosby Co.
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Prosthetic valve reoperations
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March,1979
Table I. Population characteristics Site of prosthesis
No.ofreoperations
Male/ female
Mean age at reoperation (yr.)
Aortic Mitral Tricuspid Combination
50 25
41/9 6/19
49* 53
6 8
1/5 2/6
40t 45t
Mean interval between first prosthesis and reoperation (mo.)
Prosthesis revision/ prosthesis replacement
36* 42 35* 36*
5/45 3/22
1/5
o
-Borderline significant difference from mitral reoperations (p <.0.1). tSignificant difference from mitral reoperations (p < 0.01).
tients who had reoperations prior to 1973 and who were subsequently followed through 1977. Results The over-all reoperation rate was 6.2 percent (89 reoperations/I,445 valve operations) over nearly 17 years. Of the 89 reoperations, nine percent (eight of 89) followed operations originally performed at other institutions; the remainder were originally performed at the Columbia- Presbyterian Medical Center. 6. 7 Our first reoperation occurred in 1964 in a patient with endocarditis." The yearly percentage of reoperations has remained fairly constant, except for the period 1968 through 1972, when the reoperation rate doubled (approximately II percent), reflecting our experience with aortic homograft insufficiency. 9. 10 Twice as many aortic (50) prostheses as mitral (25) necessitated reoperation, whereas only six tricuspid and eight double valves necessitated reoperation (Table I). Reoperations on aortic valves were performed predominantly in men, whereas reoperations on mitral, tricuspid, and double valves occurred mostly in women. Mitral reoperations took place at a mean age (53 years) and with a mean interval (42 months from the first prosthetic implant) which were significantly different from each of the other reoperative sites. Approximately 10 percent of aortic and mitral valve reoperations involved revision of the prosthesis rather than complete replacement. Additional procedures at the time of reoperation were more common at the mitral position (40 percent) than the aortic (14 percent) (Table II). In the aortic, mitral, and double valve groups, systemic disease related to the prosthesis accounted for 52 percent of reoperations, with the remaining reoperations divided approximately 4: I between prosthesis-related insufficiency and stenosis (Fig. I and Table III). In contrast, tricuspid reoperations were most frequently performed for prosthetic stenosis. Preoperative catheterization was more common before prosthetic mitral reoperations (81 percent) than aortic reoperations (61
Table II. Additional procedures at the time of reoperation Additional procedure
No.
Prosthetic aortic valve reoperations Mitral valve replacement Mitral valvuloplasty Coronary artery bypass Tricuspid annuloplasty Total additional procedures
50
Prosthetic mitral valve reoperations Tricuspid valve replacement Tricuspid annuloplasty Aortic valve replacement Aortic valve debridement Coronary artery bypass Plication of aneurysm Total additional procedures
25
3 2 I I 7 (14%)
5 I I 1
I I 10 (40%)
percent). Infection and emboli militated against catheterization, especially with aortic prostheses. The interval between the first and second operation was short for reoperations on paravalvular leak and infection (mean interval 23 months) but long for reoperations for prosthetic valve stenosis and embolism (mean interval 55 months). The early mortality rate was 19 percent ( 17 of 89) for the over-all series. Factors influencing the early mortality rate were (I) the reoperative site, (2) the indication for a reoperation, and (3) urgency. Early deaths for patients having aortic prostheses were 8 percent (four of 50), for those with mitral prostheses 32 percent (eight of 25), for those with tricuspid prostheses 50 percent (three of six), and for those with combination prostheses 25 percent (two of eight). Although there were early deaths attributable to reoperations on infected prostheses at each site, patients with atrioventricular prostheses were subject to an additional cause of death-occluded orifices. Nearly all early deaths occurred in patients undergoing reoperation on either an infected or stenotic prosthesis. Reoperation for em-
348
The Joumal of Thoracic and Cardiovascular Surgery
Syracuse. Bowman. Malm
REOPERATIONS ON MITRAL PROSTHESES
REOPERATIONS ON AORTIC PROSTHESES
n=25
n=50
Fig. l. Indications for reoperation.
fEmbolism lProsthetic Insuffic iency
100 -l
~
sa::
80
::> 60 (/) t-
Z
w 40 u
a::
w a.. 20 0
12
24
36
48
60
MONTHS Fig. 2. Five-year survival among patients with aortic valve reoperations. 100 ..J
« >
sa::
80
Insufficiency
::>
55%
t-
38%
(/)
z w u
a::
w
0-
20 0
[prosthetiC Stenosis Infection n =4
0% 12
24
36
48
60
MONTHS Fig. 3. Five-year survival among patients with mitral valve reoperations.
bolism, paravalvular leak, hemolysis, occluder variance, and homograft incompetence was performed with a group mortality rate of only 1.9 percent (one of 52). The urgency of reoperation was also associated with early deaths. Urgent reoperations occurred in 35 percent (31 of 89) of cases, with an early mortality rate of
32 percent (10 of 31). However, the factor of urgency predominantly affected only the high-risk group of reoperations. Sixty-four percent (24 of 37) of patients with prosthetic infection or stenosis required an urgent reoperation. In this high-risk group, an urgent reoperation increased the early mortality rate from 43 percent (16 of 37) to 67 percent (16 of 24). In the absence of prosthetic infection or prosthetic stenosis, urgent reoperations were required in only 14 percent (seven of 52) of cases and were associated with no early deaths. Factors influencing late survival were (I) the site and (2) the indication for reoperation. In general, patients fared better after aortic prosthetic reoperation than mitral prosthetic reoperation. There were too few tricuspid and combination prosthetic reoperations for late analysis. The 5 year survival rate was 57 percent (16 of 28) for aortic and 38 percent (five of 13) for mitral prosthetic reoperations performed through 1972 (Figs. 2 and 3). In the absence of infection or stenosis, the long-term survival rate rose to 69 percent (II of 16) for aortic and 55 percent (five of nine) for mitral prosthetic reoperations. Late deaths in both aortic and mitral reoperations occurred secondary to emboli. Patients with aortic prostheses also tended to die late of myocardial infarction, whereas those with mitral prostheses died late of arrhythmias and low cardiac output states (Table IV). The leading complication of prosthetic valve reoperations was the need for still another reoperation (7 percent). All six patients had reoperations for an infected prosthesis with a paravalvular leak. Other complications were re-exploration for postoperative bleeding, 2.2 percent (two of 89); creation of heart block, 3.4 percent (three of 89); and other changes in rhythm, 3.4 percent (three of 89). Reoperations compared favorably with the original valve replacement at the aortic and mitral positions (excluding early deaths) with equivalent perfusion times (130 versus 120 minutes, median), urine outputs 48 hours postoperatively (1,102 versus 1,290 c.c.), and hospital stays (24 versus 23 days, median). Discussion It is expected that experiences should vary in reoperations on prosthetic valves. Differences in frequency of referral, initial prostheses, operative techniques, and modes of follow-up limit the validity of comparing one series with another. Sandza and colleagues" reported an experience largely derived from the replacement of structurally worn Beall mitral valves and a continuing interest in paravalvular leak. II Our report reflects a long-term interest in tissue valves, dating to 1966 with
rr
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349
Prosthetic valve reoperations
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Table III. Distribution of operations, timing, and catheterizations Aortic prostheses (N A
I
B
Mitral prostheses (N
= 50)
I
I
A
C
I
B
Tricuspid prostheses (N = 6)
= 25) C
A
12 46
100 100
3 2 0
100
0 0
I
B
I
C
Combination prostheses (N = 8)
I
A
B
I
C
Prosthetic stenosis
50
I
30
66
2 0
60 100 64
8 0 0
19
II
17 66 70
13 9 1(4)
29 37 23
30 22 100
5 9 0
21 76
2 0 3
Thrombosis Pannus Tissue valve calcification (homografts)
9
25 58
66 50
I
57
0
39
0
13 124
60 100
0 0
Prosthetic insufficiency
10(5) 1(2)
Paravalvular leak Ball variance Tissue valve retraction (homografts)
I
I
21
100
0 0
Systemic pathology Infection Embolism Hemolysis
40 67
0 0 0
5 I
0
Legend: Parentheses indicate additional reoperations in which finding was incidental. Columns: A, Number of reoperations. B. Mean interval to reoperation
(months). C. Percent catheterization pre-reoperation.
Table IV. Causes of early * and late deaths Aortic prostheses Cause
Early
Arrhythmia Low output Infarction Sepsis Stroke Cancer Unknown
I 0
I
I
2 0 0 0
Late
Early
2 I 3 2 3 2 4
0 5 0 3 0 0 0
I
Late
Early
4 2 0
0 2 I 0 0 0 0
I
2 I
0
Combination prostheses
Tricuspid prostheses
Mitral prostheses
I
Late
Early
0 2 0 0 0 0 0
0
I
Late
0
I
I
0
0 0 0 0
I
0 0 0
I
'Early death: within 30 days postoperatively.
the implantation of 50 ill-fated aortic homografts'" 10 and continuing to the present with the glutaraldehydefixed, porcine xenograft.F"!" Indeed, in contrast to Sandza's finding that the rate of reoperation had increased recently because of valve wear, our experience has shown a marked diminution of wear-related replacements with the use of the porcine xenograft in all positions. Our incidence of re-replacement of porcine xenografts over the past 5 years has been only 0.5 percent (two of 372), and in both instances the reoperation was required for infection. Reoperations closely followed the incidence of prosthetic disorders at specific sites. Systemic disease was the leading indication for reoperation among aortic, mitral, and combination prosthetic valves. Reoperation for embolism was twice as frequent at the mitral as the aortic position (36 versus 18 percent), but both positions shared equally (20 percent) in infection leading to reoperation. Reoperations for paravalvular leak
followed known patterns of prosthetic disorders;' 1. 16 with mitral prostheses more frequently coming to reoperation than aortic prostheses (32 versus 20 percent). Reoperations for prosthetic stenosis were uncommon at all sites except at the tricuspid position. Tricuspid prostheses are known to risk thrombosis. 17. 18 This problem was confirmed in 83 percent of reoperations on prosthetic right-sided atrioventricular valves. There were no surprises in the distribution of population characteristics in our series of prosthetic valve reoperations. As expected, in contrast to reoperations on aortic prostheses, mitral prosthetic reoperations most often involved women, occurred at an older age, more likely included a pre-reoperative catheterization, usually spanned a longer interval from the first operation, and more frequently were associated with additional procedures at the time of reoperation. These findings predominantly reflected (in order): the increased number of women in contrast to men with mi-
The Journal of
350 Syracuse, Bowman, Maim
tral prostheses'v "'; the temporizing effect of a mitral commissurotomy (one third of the patients had a commissurotomy prior to their first prosthetic implantj-" 24; the relative safety of catheterization in the presence of an implanted mitral prosthesis'"; the diagnosticalIy subtle progression of prosthetic disorders in the mitral position'"; and the frequency of tricuspid valve dysfunction at reoperation on a prosthetic mitral valve.!? There was a clear distinction in reoperations which took place early and those which occurred late after an initial prosthetic valve implantation. Early reoperations were performed on patients with either prosthetic infection or paravalvular leak. Late reoperations were performed on patients with either emboli or obstructive gradients. Prosthetic infection occurs most frequently within the first 6 weeks of implantation." These patients often come to reoperation with subacute prosthetic endocarditis." Paravalvular leak tends to occur early in the postoperative period and can compromise an otherwise successful result. II. 16 Embolism is usualIy managed by tighter control of anticoagulatiorr'": 30 unless repeated bouts of emboli force consideration of a late reoperation. Orifice occlusion with either thrombus or pannus is usualIy a late event. 31-33 In these cases, the hemodynamic impairment is slowly progressive until the onset of ventricular failure, at which time the patient often presents urgently in a state of profound low cardiac output. Early death often was associated with urgency of reoperation. Iben and associates" in the first study of open-heart reoperations, claimed that 66 percent (four of six) of their early deaths were preventable by earlier intervention. Recently, Parr and colleagues" reported a mortality rate of 42.9 percent (six of 14) in urgent aortic valve reoperations, and Sandza and co-workers" claimed a mortality rate of 41 percent (18 of 44) in emergency prosthetic valve reoperations. Our results were similar and showed a mortality rate of 19 percent (17 of 89), which rose to 32 percent (10 of 31) when reoperations were performed as an emergency. Two particularly grave indications for reoperation were identified: prosthetic infection and prosthetic stenosis. Given these disorders, the early mortality rate was increased to 43 percent and rose stilI higher, to 67 percent, when urgent reoperation was required. In fact, except for one early death from arrhythmia in a patient with a paravalvular leak, the variations in early deaths with the site of the prosthesis were entirely secondary to reoperations for infection and stenosis. Prosthetic infections are notoriously difficult to eradicate and frequently evolve to multiple organ failure. 34 Reoperative
Thoracic and Cardiovascular Surgery
mortality figures often approach 50 percent," as confirmed in our series. The high risk involved with prosthetic stenosis in our experience differs from some reports'" but reflects the risk of urgent reoperations on patients in profound low output states from occluded atrioventricular prostheses. The most encouraging aspect of our study was the identification of a low-risk group when the indications leading to reoperation were embolism, paravalvular leak, hemolysis, occluder variance, and homograft (mortality rate only 1.9 percent). Our data suggest that even when this group of reoperations is performed urgently, favorable results may be obtained. Parr and associates," also reported a favorable early mortality rate of 3.7 percent (three of 81) in elective reoperations on aortic prostheses. Late mortality among reoperations folIowed similar patterns to early mortality. Reoperations on the lowrisk group were associated with survival curves comparable to those of an initial valve replacement through 1972. 19- 22 • 36 In contrast, most patients in the high-risk group continued to do poorly in the long term and died of renewed sepsis or refractory heart failure within the 5 year folIow-up period. It is likely that the poor longterm results are a reflection of the advanced deterioration in cardiac function which characterized the highrisk reoperations. This may indicate a fundamentalIy irreversi ble process. Reoperations are better prevented than performed. The operations are tedious and marked by dense adhesions and obliterated anatomy. 37 However, prosthetic valve reoperations can be performed with risks approaching the original operation, except in the presence of subacute prosthetic infection or end-stage prosthetic stenosis. REFERENCES Katholi RE, Nolan SP, McGuire LB: Living with prosthetic heart valves. Am Heart J 92: 162-167, 1976 2 Iben AB, Hurley EJ, Angell WW, Shumway NE: Repeat open heart surgery. Ann Thorac Surg 2:331-344,1966 3 Parr GVS, Kirklin W, Blackstone EH: The early risk of re-replacement of aortic valves. Ann Thorac Surg 23:319-322, 1977
4 Blackstone EH, Kirklin JW, Pluth JR, Turner ME, Parr GVS: The performance of the Braunwald-Cutter aortic prosthetic valve. Ann Thorae Surg 23:302-326, 1977
5 Sandza JG, Clark RE, FergusonTB, ConnersJP, Weldon CS: Replacement of prosthetic heart valves. A fifteenyear experience. J THoRAc CARDIOVASC SURG 74:864874, 1977
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6 Maim JR, Bowman FO, Jr: Surgical repair of mitral valve disease. Ann NY Acad Sci 118:503-511, 1965 7 Bowman FO, Jr, Maim JR: Prosthetic valve replacement for acquired heart disease. NY State J Med 65:30453048, 1965 8 Arnoury RA, Bowman FO Jr, MaIm JR: Endocarditis associated with intracardiac prostheses. Diagnosis, management, and prophylaxis. J THORAC CARDIOVASC SURG 51:36-48, 1966 9 Maim JR, Bowman FO Jr, Harris PO, Kaiser GA, Kovalik ATW: Results of aortic valve replacement utilizing irradiated valve homografts. Ann NY Acad Sci 147:740-747, 1969 10 Beach PM Jr, Bowman FO Jr, Kaiser GA, Parodi E, MaIm JR: Aortic valve replacement with frozen irradiated homografts. Long term evaluation. Circulation 45:Suppl 1:29-35, 1972 II Weldon CS, Ferguson TB: The elimination of periprosthetic leaks as a complication of mitral valve replacement. Ann Thorac Surg 18:447-455, 1974 12 Hannah H, Reis RL: Current status of porcine heterograft prostheses: A five year appraisal. Circulation 54:Suppl 3:27-31, 1976 13 Stinson EB, Griepp RB, Oyer PR, Shumway NE: Longterm experience with porcine aortic valve xenografts. J THORAC CARDIOVASC SURG 73:54-63, 1977 14 Mcintosh CL, Michaelis LL, Itscoitz SB, Redwood DR, Morrow AG: Atrioventricular valve replacement with the Hancock porcine xenograft. A five year clinical experience. Surgery 78:768-775, 1975 15 Mookerjee A, Hoar PF, Wicks AE, Maim JR, Misky MS: Acute hemodynamic alterations after aortic valve replacement with the glutaraldehyde-treated porcine heterograft prosthesis. J THORAC CARDIOVASC SURG 74:788797, 1977 16 Kastor JA, Akbarian M, Buckley MJ, Dinsmore RE, Sanders CA, Scannell JG, Austen WG: Para valvular leaks and hemolytic anemia following insertion of StarrEdwards aortic and mitral valves. J THORAC CARDIOVASC SURG 56:279-288, 1968 17 Starr A, Herr RH, Wood JA: Tricuspid replacement for acquired valve disease. Surg Gynecol Obstet 122: 12951310, 1966 18 Van Der Veer J, Rhyneer G, Hodam R, Kloster FE: Obstruction of tricuspid ball-valve prostheses. Circulation 43:Suppl 1:62-67, 1971 19 Bjork VO, Henze A, Holmgren A: Five years' experience with the Bjork-Shiley tilting disc valve in isolated aortic valvular disease. J THORAC CARDIOVASC SURG 68:393404, 1974 20 Starr A, Grunkemeier G, Lambert L, Okies JE, Thomas D: Mitral valve replacement. A 10 year follow-up of non-cloth covered vs. cloth covered caged ball prostheses. Circulation 54:Suppl 3:47-56, 1976 21 Barnhorst DA, Oxman HA, Connolly DC, Pluth JR, Danielson GK, Wallace RB, McGoon DC: Isolated re-
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36 37
placement of the mitral valve with the Starr-Edwards prosthesis. An II year review. J THORAC CARDIOVASC SURG 71:230-237, 1976 Barnhorst DA, Oxman HA, Connolly DC, Pluth JR, Danielson GK, Wallace RB, McGoon DC: Isolated replacement of the aortic valve with the Starr-Edwards prosthesis. A 9 year review. J THORAC CARDIOVASC SURG 70:113-118, 1975 Harber DE, Black H, Taylor WJ, Thrower WB, Ellis LB: Reoperation for mitral stenosis. Circulation 23:7-12, 1961 Levine FH, Copeland JG, Morrow AG: Prosthetic replacement of the mitral valve. Circulation 47:518-526, 1975 Braunwald E, Swan HJC (eds.): Cooperative study on cardiac catheterization. Circulation 37:Suppl 3:80-112, 1968 Brown JW, Myerowitz PD, Cann MS, Colvin SB, Mcintosh CL, Morrow AG: Clinical and hemodynamic comparisons of Kay-Shiley, Starr-Edwards No 6520 and Reis-Hancock porcine xenograft mitral valves. Surgery 76:983-991, 1974 Dismukes WE, Karchmer AW, Buckley MJ, Austen WG, Swartz MN: Prosthetic valve endocarditis. Analysis of 38 cases. Circulation 48:365-377, 1973 Braniff BA, Shumway NE, Harrison DC: Valve replacement in active bacterial endocarditis. N Engl J Med 276:1464-1467, 1967 Starr A, Bonchek L1, Anderson RP, Wood JA, Chapman RD: Late complications of aortic valve replacement with cloth-covered, composite-seat prostheses. Ann Thorac Surg 19:289-300, 1975 Bjork VO, Hense A: Encapsulation of the Bjork-Shiley aortic disc prosthesis caused by the lack of anticoagulant treatment. Scand J Thorac Cardiovasc Surg 7: 17-20, 1973 Shepard RL, Glancy DL, Stinson EB, Roberts WC: Hemodynamic confirmation of the obstruction to left ventricular inflow by a caged-ball prosthetic mitral valve. J THORAC CARDIOVASC SURG 65:252-254, 1973 Smithwick W III, Kouchoukos NI, Karp RB, Pacifico AD, Kirklin JW: Late stenosis of Starr-Edwards clothcovered prostheses. Ann Thorac Surg 20:249-255, 1975 Maronas JM, Rulfilanchos 11, Agnosti J, Figuera D: Reoperation for dysfunction of the Bjork-Shiley mitral disc prosthesis. Am Heart J 93:316-320, 1977 Roberts WC, Morrow AG: Bacterial endocarditis involving prosthetic mitral valves: clinical and pathological observations. Arch Pathol 82:164-169, 1966 Pfeiffer J, Goldschlager W, Sweatman T, Gerbode F, Selzer A: Malfunction of mitral ball valve prosthesis due to thrombus. Report of two cases with notes on early clinical diagnosis. Am J Cardiol 29:95-99, 1972 Kirklin JW, Pacifico AD: Surgery for acquired valvular heart disease. N Engl J Med 288:194-199, 1973 Macmanus Q, Okies JE, Phillips SJ, Starr A: Surgical
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considerations in patients undergoing repeat median sternotomy. J THORAC CARDIOVASC SURG 69: 138-143, 1975
Discussion DR. JACK MATLOFF Los Angeles. Calif.
My colleagues and I have evaluated our own experience with this difficult group of patients. Our experience occurred in approximately half the time span that Dr. Syracuse's review encompassed and included about half as many cases650 valve replacements. There were 16 patients requiring valve re-replacement, an over-all incidence of 2.5 percent. Eight of our patients had their initial operation elsewhere. Eight others were originally operated upon by us, but two of these eight had their reoperation elsewhere; we have included them in our follow-up as well. Ours is a small experience by comparison, and we found it to be quite different from that reported by Dr. Syracuse, probably because the experiences in the two institutions are different. Rather than predominant problems with the aortic valve, our cases were equally divided between mitral and aortic valve problems, there being seven of each. Although the sex distribution was similar, the ages did differ significantly, not only from the authors' series but from our own experience. For patients with mitral disease, our mean age was 10 years younger than that in the reported study, with a range of 18 to 64 years and a mean interval of 68 months from the first prosthetic implant, somewhat longer than that reported by Dr. Syracuse. All of the mitral prostheses in our experience had to be replaced, whereas three of seven (43 percent) patients with aortic valve operations had repair of a leak or replacement of a variant poppet. In contrast to Dr. Syracuse's experience, only one additional procedure, a bypass, was done in our experience. The distribution of disease as defined was generally similar in our experience, although we performed no reoperations involving hemografts or tricuspid valves, primarily because we had not had the initial experience with them. Our experience with the diseased tricuspid valve perhaps reflects our interest in annuloplasty in its various forms. More of our patients, (five or 31 percent) had prosthetic infections. Also, in contrast to the reported experience, only one of these infections occurred early-that is, less than 6 months after operation; the other four occurred from 2 to 12 years after operation. Three of these five patients died after reoperation. Our total mortality rate, almost all of which was early, was twice as high as that reported by Dr. Syracuse-37 percent as opposed to 19 percent. Combined valve operations were done in two patients and both died. Aortic valve operations carried a 43 percent mortality rate, but there were no early deaths among patients having mitral operations. The reoperation rate for infection was high and, when
Thoracic and Cardiovascular Surgery
combined with valve stenosis, carried twice the risk of reoperating for other causes. We performed urgent reoperation in 62 percent of the cases, versus 35 percent in this report. However the mortality rate was similar-30 percent. We do not have enough survivors to permit an actuarial analysis of long-term results. However, I believe that Dr. Syracuse's presentation of long-term results is very impressive and clearly establishes the validity of such therapy. With the exception of our mitral reoperations, we cannot concur with the authors that there is a group with a low mortality rate for such an operation. The rate of 1.9 percent is absolutely spectacular. We do agree, however, that infection is a very formidable problem. I do not believe that our differences constitute the primary lesson to be learned here. It would seem that patients having prosthetic valves must be carefully followed and cared for for the duration of their lives, particularly in relation to prophylaxis for infection and thromboembolism. In talking with such patients preoperati vely, this factor has to be stressed along with the detailing of early morbidity and mortality rates. I have one last comment and a question: To date we have not had to reoperate upon a patient with a porcine xenograft. Thus, to the limits of their durability, they are proving to be more troublefree or less troublesome in follow-up. Dr. Syracuse, in your review, have you been able to reach this conclusion about a similar prosthesis? Similarly, when you exclude your homograft experience, does it significantly change the over-all experience that you reported? I noted in the manuscript that there were a number of homografts involved. DR. NORMAN E. SHUMWAY Palo Alto, Calif.
Like Dr. Matloff, we were stimulated to review the experience with prosthetic valve reoperations at Stanford. Ninety-one patients were reoperated upon at least once after aortic valve replacement. Prosthetic insufficiency was the indication in the majority of cases, 58 percent, endocarditis in 25 percent and systemic disease in only II percent. These figures are a considerable contrast to the indications related by Dr. Syracuse, We had almost an equal number of patients (110) reoperated upon at least once after mitral valve replacement. Prosthetic insufficiency accounted for 46 percent of the indications, systemic disease, usually embolic phenomena, 31 percent (which more closely approximates the indications listed by Dr. Syracuse), and endocarditis, only 7 percent. Periprosthetic leaks and tissue valve deterioration in the homograft series led to 48 reoperations in both the mitral and the aortic groups. Fifteen of 110 patients reoperated upon for mitral prosthetic problems underwent some kind of additional procedure, and 10 of the 91 having aortic reoperations had an additional procedure. These numbers are lower than the ones mentioned by the authors. The early hospital or 30 day mortality rate was 8 percent
Volume n Number 3
Prosthetic valve reoperations
35 3
March, 1979
for the mitral reoperations and 13 percent for the aortic reoperations. I do not quite understand the differences in these figures. The late mortality rate was similarly greater in the aortic series-33 percent versus 25 percent. Congestive heart failure was the most common cause of death, early or late, in either category. The 5 year survival rate was approximately 66 percent for the two grups. These figures differ only slightly from those listed by Dr. Syracuse. In summary, we agree with the authors that an aggressive approach to the patient in need of reoperation after valve replacement is certainly well supported, not only by the data from Columbia, but also by the experience listed here. DR. RONALDP. GRUNWALD Spokane. Wash.
I recently reviewed my total experience with reoperation in the adult. Over a 12 year period there were 58 cardiopulmonary bypass procedures in 53 patients. There were no operative deaths, and only one patient required reoperation for postoperative bleeding after the second procedure. The operative time, pump time, blood requirements, hospital stay, and complication rate were not significantly different from those in our primary operations. Of the 58 procedures, 19 (approximately one third) were for valvular heart disease. Although there were no deaths in this group, the postoperative morbidity in this group correlated well with their preoperative functional status. I would like to stress the following somewhat obvious points. First, closing the pericardium at the first procedure makes a subsequent procedure easier. However, even if it has been left open, the operation can be performed with as Iowa risk as the primary operation. Second, indications for reoperation should be the same as for the initial procedure, and the operation should not be delayed to the point that the morbidity and the long-term results are compromised for fear of a higher preoperative mortality rate. DR. EDWARD A. SMELOFF Sacramento, Calif
Since 1966 we have performed only one reoperation for ball variance. This was in an aortic prosthesis in which the ball became very small. The valve was very easily repaired by replacing the poppet. We have performed three other reoperations in aortic valves. Two valves required replacement because of apparent increase in size of the anulus or perhaps because too small a valve had been inserted originally. There were no deaths after reoperation on aortic prostheses. An advantage of the use of the ball valve in this instance is that the ball can be removed if the peri valvular leak is small and the suture can be placed beneath the valve to repair the leak without replacement of the prosthesis itself. In the mitral region, we have had IO reoperations in the past 10 years for an incidence of 7.5 percent. Three of them were for perivalvular leak and seven were for either pannus formation or thrombosis.
Three of the seven were in children who had not been given anticoagulants because of their small size and the difficulty in maintaining anticoagulation in children. One of these children died just as he was being placed on the operating table. Four adults had reoperation for pannus formation. Two definitely were not receiving anticoagulation and a third may not have been. Only one patient who was receiving regulated anticoagulation had pannus formation. There was only one late death in the mitral reoperation series of seven patients. In this patient a thrombosed Smeloff-Cutter prosthesis was replaced with a Hancock prosthesis. If we study these patients more carefully to determine their tendency toward thrombosis or normal coagulation, perhaps we can select patients that will be either low risk or high risk for thromboembolism and, therefore, determine the type of valve replacement required. DR. S Y R A C USE (Closing) I would like to thank each of the discussers for reviewing the data at their institutions and balancing them against our data. We are now constructing a data base for the assignment of risk to an increasingly large population of patients. Clearly, reoperations are better prevented than performed. Dr. Matloff raised questions regarding the specific valves we have used. The intent of our analysis was to emphasize the broad categories of disorders which affect valves in general irrespective of specific mechanical design. No valve has been free from problems requiring a reoperation at some time. The ball valves have been in wide use longer than others, and much of our analysis was drawn from reoperations on such valves. We now use the porcine xenograft in all positions for all valve replacements, but fully expect that as more experience accumulates, this too will have its detractors. Predominant aortic prostheses we have used and the reoperations required are as follows: 230 Starr-Edwards valves, 26 reoperations; 172 Hancock xenografts, three reoperations; 50 homografts, 13 reoperations; 40 Bjork-Shiley valves, two reoperations; and 94 Braunwald-Cutter valves, four reoperations. Incidentally, supported by this analysis of the prospect of low-risk reoperations at our institution, we have subsequently followed the lead of the groups at Alabama and the Mayo Clinic in replacing Braunwald-Cutter valves in view of projected poppet escape. To date 15 patients have come to purely elective replacement; all prostheses have shown severe cloth wear and most have shown poppet variance. Predominant mitral prostheses we have used and the reoperations required are as follows: 404 Starr-Edwards valves, 21 reoperations; 200 Hancock xenografts, one reoperation; and 41 Braunwald-Cutter valves, two reoperations. I would like to acknowledge Dr. Shumway's previous contribution. His paper published in 1966 is one of the first in the broad subject of repeat open-heart operation, and this recent updating from Stanford is most interesting.
The Journal of
354 Syracuse, Bowman, Maim
Dr. Smeloff, we have not used your valve so that I can make no comment, Dr. Grunwald, we have had similarly unimpressive complication rates at reoperation if early deaths are excluded. It seems that if those patients survive the reoperation, their hospital stay as well as other morbidity parameters are remarkably low. DR. MAL M (Closing) I want to comment on prevention or prophylaxis. In half of our infected valves, there was some identifiable episode in the follow-up period which was associated with the bacteremia. It is important to constantly reinforce with our patients the need
Thoracic and Cardiovascular Surgery
for prophylaxis of antibiotics. Penicillin is inadequate prophylaxis. These patients should receive either cloxacillin or ampicillin and, if they are having a urologic procedure or even urethral catheterization, they should have gentamycin or kanamycin or some appropriate coverage. Probably the most difficult thing for us to identify is ball variance or pannus or thrombus around the prosthesis, particularly in patients with emboli. There is some interesting work going on now, not only with the M mode echo but with sector scanning, that might provide valuable information in evaluating these prostheses.
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Donald C. Syracuse, M.D., Frederick O. Bowman, Jr., M.D., and James R. Maim, M.D., New York, N. Y.
Reoperation on prosthetic valves assumes greater importance as the population at risk increases' and the limited durability of prosthetic valves becomes apparent. 2-,'; To define the group of patients who undergo reoperation on prosthetic valves and the factors influencing early and late survival, we reviewed the experiences at the Columbia-Presbyterian Medical Center.
Methods A retrospective study was conducted on 89 reoperations performed on 83 adult patients from a total of 1,445 valve replacement operations from December, 1960, through July, 1977. Only adults who were reFrom the Thoracic and Cardiac Surgical Service, Department of Surgery, Columbia University College of Physicians and Surgeons, Presbyterian Hospital, New York, N.Y. 10032. Read at the Fourth Annual Meeting of The Samson Thoracic Surgical Society, Coronado, Calif., June 4-7, 1978. Address for reprints: Donald C. Syracuse, M.D., Thoracic and Cardiac Surgical Service, Department of Surgery, Presbyterian Hospital, 630 West 168 St., New York, N. Y. 10032.
346
operated upon for a prosthesis-related disorder were included. Reoperations were organized by the site of the prosthesis: aortic, mitral, tricuspid, or combination (aortic and mitral or mitral and tricuspid). There were no reoperations on patients having triple valve replacement and none which simultaneously involved prosthetic aortic and tricuspid valves. Three categories of prosthesis-related disorders were assigned: stenosis, insufficiency, and systemic disease. Indications for reoperation at each site were organized under these categories, subdivided by the specific disorder prompting reoperation, and designated as urgent or elective. All reoperations were considered as elective except those on moribund patients whose death was imminent. There was a minimum follow-up period of 6 months. Data were complete on all save five patients who were known to be long-term survivors but were subsequently lost to follow-up. Early and late mortality and morbidity rates reflected patient status through December, 1977. Five-year survival curves were generated on pa-
0022-5223/79/030346+09$00.90/0 © 1979 The C. V. Mosby Co.
Volume 77 Number 3
Prosthetic valve reoperations
347
March,1979
Table I. Population characteristics Site of prosthesis
No.ofreoperations
Male/ female
Mean age at reoperation (yr.)
Aortic Mitral Tricuspid Combination
50 25
41/9 6/19
49* 53
6 8
1/5 2/6
40t 45t
Mean interval between first prosthesis and reoperation (mo.)
Prosthesis revision/ prosthesis replacement
36* 42 35* 36*
5/45 3/22
1/5
o
-Borderline significant difference from mitral reoperations (p <.0.1). tSignificant difference from mitral reoperations (p < 0.01).
tients who had reoperations prior to 1973 and who were subsequently followed through 1977. Results The over-all reoperation rate was 6.2 percent (89 reoperations/I,445 valve operations) over nearly 17 years. Of the 89 reoperations, nine percent (eight of 89) followed operations originally performed at other institutions; the remainder were originally performed at the Columbia- Presbyterian Medical Center. 6. 7 Our first reoperation occurred in 1964 in a patient with endocarditis." The yearly percentage of reoperations has remained fairly constant, except for the period 1968 through 1972, when the reoperation rate doubled (approximately II percent), reflecting our experience with aortic homograft insufficiency. 9. 10 Twice as many aortic (50) prostheses as mitral (25) necessitated reoperation, whereas only six tricuspid and eight double valves necessitated reoperation (Table I). Reoperations on aortic valves were performed predominantly in men, whereas reoperations on mitral, tricuspid, and double valves occurred mostly in women. Mitral reoperations took place at a mean age (53 years) and with a mean interval (42 months from the first prosthetic implant) which were significantly different from each of the other reoperative sites. Approximately 10 percent of aortic and mitral valve reoperations involved revision of the prosthesis rather than complete replacement. Additional procedures at the time of reoperation were more common at the mitral position (40 percent) than the aortic (14 percent) (Table II). In the aortic, mitral, and double valve groups, systemic disease related to the prosthesis accounted for 52 percent of reoperations, with the remaining reoperations divided approximately 4: I between prosthesis-related insufficiency and stenosis (Fig. I and Table III). In contrast, tricuspid reoperations were most frequently performed for prosthetic stenosis. Preoperative catheterization was more common before prosthetic mitral reoperations (81 percent) than aortic reoperations (61
Table II. Additional procedures at the time of reoperation Additional procedure
No.
Prosthetic aortic valve reoperations Mitral valve replacement Mitral valvuloplasty Coronary artery bypass Tricuspid annuloplasty Total additional procedures
50
Prosthetic mitral valve reoperations Tricuspid valve replacement Tricuspid annuloplasty Aortic valve replacement Aortic valve debridement Coronary artery bypass Plication of aneurysm Total additional procedures
25
3 2 I I 7 (14%)
5 I I 1
I I 10 (40%)
percent). Infection and emboli militated against catheterization, especially with aortic prostheses. The interval between the first and second operation was short for reoperations on paravalvular leak and infection (mean interval 23 months) but long for reoperations for prosthetic valve stenosis and embolism (mean interval 55 months). The early mortality rate was 19 percent ( 17 of 89) for the over-all series. Factors influencing the early mortality rate were (I) the reoperative site, (2) the indication for a reoperation, and (3) urgency. Early deaths for patients having aortic prostheses were 8 percent (four of 50), for those with mitral prostheses 32 percent (eight of 25), for those with tricuspid prostheses 50 percent (three of six), and for those with combination prostheses 25 percent (two of eight). Although there were early deaths attributable to reoperations on infected prostheses at each site, patients with atrioventricular prostheses were subject to an additional cause of death-occluded orifices. Nearly all early deaths occurred in patients undergoing reoperation on either an infected or stenotic prosthesis. Reoperation for em-
348
The Joumal of Thoracic and Cardiovascular Surgery
Syracuse. Bowman. Malm
REOPERATIONS ON MITRAL PROSTHESES
REOPERATIONS ON AORTIC PROSTHESES
n=25
n=50
Fig. l. Indications for reoperation.
fEmbolism lProsthetic Insuffic iency
100 -l
~
sa::
80
::> 60 (/) t-
Z
w 40 u
a::
w a.. 20 0
12
24
36
48
60
MONTHS Fig. 2. Five-year survival among patients with aortic valve reoperations. 100 ..J
« >
sa::
80
Insufficiency
::>
55%
t-
38%
(/)
z w u
a::
w
0-
20 0
[prosthetiC Stenosis Infection n =4
0% 12
24
36
48
60
MONTHS Fig. 3. Five-year survival among patients with mitral valve reoperations.
bolism, paravalvular leak, hemolysis, occluder variance, and homograft incompetence was performed with a group mortality rate of only 1.9 percent (one of 52). The urgency of reoperation was also associated with early deaths. Urgent reoperations occurred in 35 percent (31 of 89) of cases, with an early mortality rate of
32 percent (10 of 31). However, the factor of urgency predominantly affected only the high-risk group of reoperations. Sixty-four percent (24 of 37) of patients with prosthetic infection or stenosis required an urgent reoperation. In this high-risk group, an urgent reoperation increased the early mortality rate from 43 percent (16 of 37) to 67 percent (16 of 24). In the absence of prosthetic infection or prosthetic stenosis, urgent reoperations were required in only 14 percent (seven of 52) of cases and were associated with no early deaths. Factors influencing late survival were (I) the site and (2) the indication for reoperation. In general, patients fared better after aortic prosthetic reoperation than mitral prosthetic reoperation. There were too few tricuspid and combination prosthetic reoperations for late analysis. The 5 year survival rate was 57 percent (16 of 28) for aortic and 38 percent (five of 13) for mitral prosthetic reoperations performed through 1972 (Figs. 2 and 3). In the absence of infection or stenosis, the long-term survival rate rose to 69 percent (II of 16) for aortic and 55 percent (five of nine) for mitral prosthetic reoperations. Late deaths in both aortic and mitral reoperations occurred secondary to emboli. Patients with aortic prostheses also tended to die late of myocardial infarction, whereas those with mitral prostheses died late of arrhythmias and low cardiac output states (Table IV). The leading complication of prosthetic valve reoperations was the need for still another reoperation (7 percent). All six patients had reoperations for an infected prosthesis with a paravalvular leak. Other complications were re-exploration for postoperative bleeding, 2.2 percent (two of 89); creation of heart block, 3.4 percent (three of 89); and other changes in rhythm, 3.4 percent (three of 89). Reoperations compared favorably with the original valve replacement at the aortic and mitral positions (excluding early deaths) with equivalent perfusion times (130 versus 120 minutes, median), urine outputs 48 hours postoperatively (1,102 versus 1,290 c.c.), and hospital stays (24 versus 23 days, median). Discussion It is expected that experiences should vary in reoperations on prosthetic valves. Differences in frequency of referral, initial prostheses, operative techniques, and modes of follow-up limit the validity of comparing one series with another. Sandza and colleagues" reported an experience largely derived from the replacement of structurally worn Beall mitral valves and a continuing interest in paravalvular leak. II Our report reflects a long-term interest in tissue valves, dating to 1966 with
rr
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349
Prosthetic valve reoperations
March. 1979
Table III. Distribution of operations, timing, and catheterizations Aortic prostheses (N A
I
B
Mitral prostheses (N
= 50)
I
I
A
C
I
B
Tricuspid prostheses (N = 6)
= 25) C
A
12 46
100 100
3 2 0
100
0 0
I
B
I
C
Combination prostheses (N = 8)
I
A
B
I
C
Prosthetic stenosis
50
I
30
66
2 0
60 100 64
8 0 0
19
II
17 66 70
13 9 1(4)
29 37 23
30 22 100
5 9 0
21 76
2 0 3
Thrombosis Pannus Tissue valve calcification (homografts)
9
25 58
66 50
I
57
0
39
0
13 124
60 100
0 0
Prosthetic insufficiency
10(5) 1(2)
Paravalvular leak Ball variance Tissue valve retraction (homografts)
I
I
21
100
0 0
Systemic pathology Infection Embolism Hemolysis
40 67
0 0 0
5 I
0
Legend: Parentheses indicate additional reoperations in which finding was incidental. Columns: A, Number of reoperations. B. Mean interval to reoperation
(months). C. Percent catheterization pre-reoperation.
Table IV. Causes of early * and late deaths Aortic prostheses Cause
Early
Arrhythmia Low output Infarction Sepsis Stroke Cancer Unknown
I 0
I
I
2 0 0 0
Late
Early
2 I 3 2 3 2 4
0 5 0 3 0 0 0
I
Late
Early
4 2 0
0 2 I 0 0 0 0
I
2 I
0
Combination prostheses
Tricuspid prostheses
Mitral prostheses
I
Late
Early
0 2 0 0 0 0 0
0
I
Late
0
I
I
0
0 0 0 0
I
0 0 0
I
'Early death: within 30 days postoperatively.
the implantation of 50 ill-fated aortic homografts'" 10 and continuing to the present with the glutaraldehydefixed, porcine xenograft.F"!" Indeed, in contrast to Sandza's finding that the rate of reoperation had increased recently because of valve wear, our experience has shown a marked diminution of wear-related replacements with the use of the porcine xenograft in all positions. Our incidence of re-replacement of porcine xenografts over the past 5 years has been only 0.5 percent (two of 372), and in both instances the reoperation was required for infection. Reoperations closely followed the incidence of prosthetic disorders at specific sites. Systemic disease was the leading indication for reoperation among aortic, mitral, and combination prosthetic valves. Reoperation for embolism was twice as frequent at the mitral as the aortic position (36 versus 18 percent), but both positions shared equally (20 percent) in infection leading to reoperation. Reoperations for paravalvular leak
followed known patterns of prosthetic disorders;' 1. 16 with mitral prostheses more frequently coming to reoperation than aortic prostheses (32 versus 20 percent). Reoperations for prosthetic stenosis were uncommon at all sites except at the tricuspid position. Tricuspid prostheses are known to risk thrombosis. 17. 18 This problem was confirmed in 83 percent of reoperations on prosthetic right-sided atrioventricular valves. There were no surprises in the distribution of population characteristics in our series of prosthetic valve reoperations. As expected, in contrast to reoperations on aortic prostheses, mitral prosthetic reoperations most often involved women, occurred at an older age, more likely included a pre-reoperative catheterization, usually spanned a longer interval from the first operation, and more frequently were associated with additional procedures at the time of reoperation. These findings predominantly reflected (in order): the increased number of women in contrast to men with mi-
The Journal of
350 Syracuse, Bowman, Maim
tral prostheses'v "'; the temporizing effect of a mitral commissurotomy (one third of the patients had a commissurotomy prior to their first prosthetic implantj-" 24; the relative safety of catheterization in the presence of an implanted mitral prosthesis'"; the diagnosticalIy subtle progression of prosthetic disorders in the mitral position'"; and the frequency of tricuspid valve dysfunction at reoperation on a prosthetic mitral valve.!? There was a clear distinction in reoperations which took place early and those which occurred late after an initial prosthetic valve implantation. Early reoperations were performed on patients with either prosthetic infection or paravalvular leak. Late reoperations were performed on patients with either emboli or obstructive gradients. Prosthetic infection occurs most frequently within the first 6 weeks of implantation." These patients often come to reoperation with subacute prosthetic endocarditis." Paravalvular leak tends to occur early in the postoperative period and can compromise an otherwise successful result. II. 16 Embolism is usualIy managed by tighter control of anticoagulatiorr'": 30 unless repeated bouts of emboli force consideration of a late reoperation. Orifice occlusion with either thrombus or pannus is usualIy a late event. 31-33 In these cases, the hemodynamic impairment is slowly progressive until the onset of ventricular failure, at which time the patient often presents urgently in a state of profound low cardiac output. Early death often was associated with urgency of reoperation. Iben and associates" in the first study of open-heart reoperations, claimed that 66 percent (four of six) of their early deaths were preventable by earlier intervention. Recently, Parr and colleagues" reported a mortality rate of 42.9 percent (six of 14) in urgent aortic valve reoperations, and Sandza and co-workers" claimed a mortality rate of 41 percent (18 of 44) in emergency prosthetic valve reoperations. Our results were similar and showed a mortality rate of 19 percent (17 of 89), which rose to 32 percent (10 of 31) when reoperations were performed as an emergency. Two particularly grave indications for reoperation were identified: prosthetic infection and prosthetic stenosis. Given these disorders, the early mortality rate was increased to 43 percent and rose stilI higher, to 67 percent, when urgent reoperation was required. In fact, except for one early death from arrhythmia in a patient with a paravalvular leak, the variations in early deaths with the site of the prosthesis were entirely secondary to reoperations for infection and stenosis. Prosthetic infections are notoriously difficult to eradicate and frequently evolve to multiple organ failure. 34 Reoperative
Thoracic and Cardiovascular Surgery
mortality figures often approach 50 percent," as confirmed in our series. The high risk involved with prosthetic stenosis in our experience differs from some reports'" but reflects the risk of urgent reoperations on patients in profound low output states from occluded atrioventricular prostheses. The most encouraging aspect of our study was the identification of a low-risk group when the indications leading to reoperation were embolism, paravalvular leak, hemolysis, occluder variance, and homograft (mortality rate only 1.9 percent). Our data suggest that even when this group of reoperations is performed urgently, favorable results may be obtained. Parr and associates," also reported a favorable early mortality rate of 3.7 percent (three of 81) in elective reoperations on aortic prostheses. Late mortality among reoperations folIowed similar patterns to early mortality. Reoperations on the lowrisk group were associated with survival curves comparable to those of an initial valve replacement through 1972. 19- 22 • 36 In contrast, most patients in the high-risk group continued to do poorly in the long term and died of renewed sepsis or refractory heart failure within the 5 year folIow-up period. It is likely that the poor longterm results are a reflection of the advanced deterioration in cardiac function which characterized the highrisk reoperations. This may indicate a fundamentalIy irreversi ble process. Reoperations are better prevented than performed. The operations are tedious and marked by dense adhesions and obliterated anatomy. 37 However, prosthetic valve reoperations can be performed with risks approaching the original operation, except in the presence of subacute prosthetic infection or end-stage prosthetic stenosis. REFERENCES Katholi RE, Nolan SP, McGuire LB: Living with prosthetic heart valves. Am Heart J 92: 162-167, 1976 2 Iben AB, Hurley EJ, Angell WW, Shumway NE: Repeat open heart surgery. Ann Thorac Surg 2:331-344,1966 3 Parr GVS, Kirklin W, Blackstone EH: The early risk of re-replacement of aortic valves. Ann Thorac Surg 23:319-322, 1977
4 Blackstone EH, Kirklin JW, Pluth JR, Turner ME, Parr GVS: The performance of the Braunwald-Cutter aortic prosthetic valve. Ann Thorae Surg 23:302-326, 1977
5 Sandza JG, Clark RE, FergusonTB, ConnersJP, Weldon CS: Replacement of prosthetic heart valves. A fifteenyear experience. J THoRAc CARDIOVASC SURG 74:864874, 1977
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March. 1979
6 Maim JR, Bowman FO, Jr: Surgical repair of mitral valve disease. Ann NY Acad Sci 118:503-511, 1965 7 Bowman FO, Jr, Maim JR: Prosthetic valve replacement for acquired heart disease. NY State J Med 65:30453048, 1965 8 Arnoury RA, Bowman FO Jr, MaIm JR: Endocarditis associated with intracardiac prostheses. Diagnosis, management, and prophylaxis. J THORAC CARDIOVASC SURG 51:36-48, 1966 9 Maim JR, Bowman FO Jr, Harris PO, Kaiser GA, Kovalik ATW: Results of aortic valve replacement utilizing irradiated valve homografts. Ann NY Acad Sci 147:740-747, 1969 10 Beach PM Jr, Bowman FO Jr, Kaiser GA, Parodi E, MaIm JR: Aortic valve replacement with frozen irradiated homografts. Long term evaluation. Circulation 45:Suppl 1:29-35, 1972 II Weldon CS, Ferguson TB: The elimination of periprosthetic leaks as a complication of mitral valve replacement. Ann Thorac Surg 18:447-455, 1974 12 Hannah H, Reis RL: Current status of porcine heterograft prostheses: A five year appraisal. Circulation 54:Suppl 3:27-31, 1976 13 Stinson EB, Griepp RB, Oyer PR, Shumway NE: Longterm experience with porcine aortic valve xenografts. J THORAC CARDIOVASC SURG 73:54-63, 1977 14 Mcintosh CL, Michaelis LL, Itscoitz SB, Redwood DR, Morrow AG: Atrioventricular valve replacement with the Hancock porcine xenograft. A five year clinical experience. Surgery 78:768-775, 1975 15 Mookerjee A, Hoar PF, Wicks AE, Maim JR, Misky MS: Acute hemodynamic alterations after aortic valve replacement with the glutaraldehyde-treated porcine heterograft prosthesis. J THORAC CARDIOVASC SURG 74:788797, 1977 16 Kastor JA, Akbarian M, Buckley MJ, Dinsmore RE, Sanders CA, Scannell JG, Austen WG: Para valvular leaks and hemolytic anemia following insertion of StarrEdwards aortic and mitral valves. J THORAC CARDIOVASC SURG 56:279-288, 1968 17 Starr A, Herr RH, Wood JA: Tricuspid replacement for acquired valve disease. Surg Gynecol Obstet 122: 12951310, 1966 18 Van Der Veer J, Rhyneer G, Hodam R, Kloster FE: Obstruction of tricuspid ball-valve prostheses. Circulation 43:Suppl 1:62-67, 1971 19 Bjork VO, Henze A, Holmgren A: Five years' experience with the Bjork-Shiley tilting disc valve in isolated aortic valvular disease. J THORAC CARDIOVASC SURG 68:393404, 1974 20 Starr A, Grunkemeier G, Lambert L, Okies JE, Thomas D: Mitral valve replacement. A 10 year follow-up of non-cloth covered vs. cloth covered caged ball prostheses. Circulation 54:Suppl 3:47-56, 1976 21 Barnhorst DA, Oxman HA, Connolly DC, Pluth JR, Danielson GK, Wallace RB, McGoon DC: Isolated re-
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36 37
placement of the mitral valve with the Starr-Edwards prosthesis. An II year review. J THORAC CARDIOVASC SURG 71:230-237, 1976 Barnhorst DA, Oxman HA, Connolly DC, Pluth JR, Danielson GK, Wallace RB, McGoon DC: Isolated replacement of the aortic valve with the Starr-Edwards prosthesis. A 9 year review. J THORAC CARDIOVASC SURG 70:113-118, 1975 Harber DE, Black H, Taylor WJ, Thrower WB, Ellis LB: Reoperation for mitral stenosis. Circulation 23:7-12, 1961 Levine FH, Copeland JG, Morrow AG: Prosthetic replacement of the mitral valve. Circulation 47:518-526, 1975 Braunwald E, Swan HJC (eds.): Cooperative study on cardiac catheterization. Circulation 37:Suppl 3:80-112, 1968 Brown JW, Myerowitz PD, Cann MS, Colvin SB, Mcintosh CL, Morrow AG: Clinical and hemodynamic comparisons of Kay-Shiley, Starr-Edwards No 6520 and Reis-Hancock porcine xenograft mitral valves. Surgery 76:983-991, 1974 Dismukes WE, Karchmer AW, Buckley MJ, Austen WG, Swartz MN: Prosthetic valve endocarditis. Analysis of 38 cases. Circulation 48:365-377, 1973 Braniff BA, Shumway NE, Harrison DC: Valve replacement in active bacterial endocarditis. N Engl J Med 276:1464-1467, 1967 Starr A, Bonchek L1, Anderson RP, Wood JA, Chapman RD: Late complications of aortic valve replacement with cloth-covered, composite-seat prostheses. Ann Thorac Surg 19:289-300, 1975 Bjork VO, Hense A: Encapsulation of the Bjork-Shiley aortic disc prosthesis caused by the lack of anticoagulant treatment. Scand J Thorac Cardiovasc Surg 7: 17-20, 1973 Shepard RL, Glancy DL, Stinson EB, Roberts WC: Hemodynamic confirmation of the obstruction to left ventricular inflow by a caged-ball prosthetic mitral valve. J THORAC CARDIOVASC SURG 65:252-254, 1973 Smithwick W III, Kouchoukos NI, Karp RB, Pacifico AD, Kirklin JW: Late stenosis of Starr-Edwards clothcovered prostheses. Ann Thorac Surg 20:249-255, 1975 Maronas JM, Rulfilanchos 11, Agnosti J, Figuera D: Reoperation for dysfunction of the Bjork-Shiley mitral disc prosthesis. Am Heart J 93:316-320, 1977 Roberts WC, Morrow AG: Bacterial endocarditis involving prosthetic mitral valves: clinical and pathological observations. Arch Pathol 82:164-169, 1966 Pfeiffer J, Goldschlager W, Sweatman T, Gerbode F, Selzer A: Malfunction of mitral ball valve prosthesis due to thrombus. Report of two cases with notes on early clinical diagnosis. Am J Cardiol 29:95-99, 1972 Kirklin JW, Pacifico AD: Surgery for acquired valvular heart disease. N Engl J Med 288:194-199, 1973 Macmanus Q, Okies JE, Phillips SJ, Starr A: Surgical
The Journal of
352 Syracuse, Bowman, Maim
considerations in patients undergoing repeat median sternotomy. J THORAC CARDIOVASC SURG 69: 138-143, 1975
Discussion DR. JACK MATLOFF Los Angeles. Calif.
My colleagues and I have evaluated our own experience with this difficult group of patients. Our experience occurred in approximately half the time span that Dr. Syracuse's review encompassed and included about half as many cases650 valve replacements. There were 16 patients requiring valve re-replacement, an over-all incidence of 2.5 percent. Eight of our patients had their initial operation elsewhere. Eight others were originally operated upon by us, but two of these eight had their reoperation elsewhere; we have included them in our follow-up as well. Ours is a small experience by comparison, and we found it to be quite different from that reported by Dr. Syracuse, probably because the experiences in the two institutions are different. Rather than predominant problems with the aortic valve, our cases were equally divided between mitral and aortic valve problems, there being seven of each. Although the sex distribution was similar, the ages did differ significantly, not only from the authors' series but from our own experience. For patients with mitral disease, our mean age was 10 years younger than that in the reported study, with a range of 18 to 64 years and a mean interval of 68 months from the first prosthetic implant, somewhat longer than that reported by Dr. Syracuse. All of the mitral prostheses in our experience had to be replaced, whereas three of seven (43 percent) patients with aortic valve operations had repair of a leak or replacement of a variant poppet. In contrast to Dr. Syracuse's experience, only one additional procedure, a bypass, was done in our experience. The distribution of disease as defined was generally similar in our experience, although we performed no reoperations involving hemografts or tricuspid valves, primarily because we had not had the initial experience with them. Our experience with the diseased tricuspid valve perhaps reflects our interest in annuloplasty in its various forms. More of our patients, (five or 31 percent) had prosthetic infections. Also, in contrast to the reported experience, only one of these infections occurred early-that is, less than 6 months after operation; the other four occurred from 2 to 12 years after operation. Three of these five patients died after reoperation. Our total mortality rate, almost all of which was early, was twice as high as that reported by Dr. Syracuse-37 percent as opposed to 19 percent. Combined valve operations were done in two patients and both died. Aortic valve operations carried a 43 percent mortality rate, but there were no early deaths among patients having mitral operations. The reoperation rate for infection was high and, when
Thoracic and Cardiovascular Surgery
combined with valve stenosis, carried twice the risk of reoperating for other causes. We performed urgent reoperation in 62 percent of the cases, versus 35 percent in this report. However the mortality rate was similar-30 percent. We do not have enough survivors to permit an actuarial analysis of long-term results. However, I believe that Dr. Syracuse's presentation of long-term results is very impressive and clearly establishes the validity of such therapy. With the exception of our mitral reoperations, we cannot concur with the authors that there is a group with a low mortality rate for such an operation. The rate of 1.9 percent is absolutely spectacular. We do agree, however, that infection is a very formidable problem. I do not believe that our differences constitute the primary lesson to be learned here. It would seem that patients having prosthetic valves must be carefully followed and cared for for the duration of their lives, particularly in relation to prophylaxis for infection and thromboembolism. In talking with such patients preoperati vely, this factor has to be stressed along with the detailing of early morbidity and mortality rates. I have one last comment and a question: To date we have not had to reoperate upon a patient with a porcine xenograft. Thus, to the limits of their durability, they are proving to be more troublefree or less troublesome in follow-up. Dr. Syracuse, in your review, have you been able to reach this conclusion about a similar prosthesis? Similarly, when you exclude your homograft experience, does it significantly change the over-all experience that you reported? I noted in the manuscript that there were a number of homografts involved. DR. NORMAN E. SHUMWAY Palo Alto, Calif.
Like Dr. Matloff, we were stimulated to review the experience with prosthetic valve reoperations at Stanford. Ninety-one patients were reoperated upon at least once after aortic valve replacement. Prosthetic insufficiency was the indication in the majority of cases, 58 percent, endocarditis in 25 percent and systemic disease in only II percent. These figures are a considerable contrast to the indications related by Dr. Syracuse, We had almost an equal number of patients (110) reoperated upon at least once after mitral valve replacement. Prosthetic insufficiency accounted for 46 percent of the indications, systemic disease, usually embolic phenomena, 31 percent (which more closely approximates the indications listed by Dr. Syracuse), and endocarditis, only 7 percent. Periprosthetic leaks and tissue valve deterioration in the homograft series led to 48 reoperations in both the mitral and the aortic groups. Fifteen of 110 patients reoperated upon for mitral prosthetic problems underwent some kind of additional procedure, and 10 of the 91 having aortic reoperations had an additional procedure. These numbers are lower than the ones mentioned by the authors. The early hospital or 30 day mortality rate was 8 percent
Volume n Number 3
Prosthetic valve reoperations
35 3
March, 1979
for the mitral reoperations and 13 percent for the aortic reoperations. I do not quite understand the differences in these figures. The late mortality rate was similarly greater in the aortic series-33 percent versus 25 percent. Congestive heart failure was the most common cause of death, early or late, in either category. The 5 year survival rate was approximately 66 percent for the two grups. These figures differ only slightly from those listed by Dr. Syracuse. In summary, we agree with the authors that an aggressive approach to the patient in need of reoperation after valve replacement is certainly well supported, not only by the data from Columbia, but also by the experience listed here. DR. RONALDP. GRUNWALD Spokane. Wash.
I recently reviewed my total experience with reoperation in the adult. Over a 12 year period there were 58 cardiopulmonary bypass procedures in 53 patients. There were no operative deaths, and only one patient required reoperation for postoperative bleeding after the second procedure. The operative time, pump time, blood requirements, hospital stay, and complication rate were not significantly different from those in our primary operations. Of the 58 procedures, 19 (approximately one third) were for valvular heart disease. Although there were no deaths in this group, the postoperative morbidity in this group correlated well with their preoperative functional status. I would like to stress the following somewhat obvious points. First, closing the pericardium at the first procedure makes a subsequent procedure easier. However, even if it has been left open, the operation can be performed with as Iowa risk as the primary operation. Second, indications for reoperation should be the same as for the initial procedure, and the operation should not be delayed to the point that the morbidity and the long-term results are compromised for fear of a higher preoperative mortality rate. DR. EDWARD A. SMELOFF Sacramento, Calif
Since 1966 we have performed only one reoperation for ball variance. This was in an aortic prosthesis in which the ball became very small. The valve was very easily repaired by replacing the poppet. We have performed three other reoperations in aortic valves. Two valves required replacement because of apparent increase in size of the anulus or perhaps because too small a valve had been inserted originally. There were no deaths after reoperation on aortic prostheses. An advantage of the use of the ball valve in this instance is that the ball can be removed if the peri valvular leak is small and the suture can be placed beneath the valve to repair the leak without replacement of the prosthesis itself. In the mitral region, we have had IO reoperations in the past 10 years for an incidence of 7.5 percent. Three of them were for perivalvular leak and seven were for either pannus formation or thrombosis.
Three of the seven were in children who had not been given anticoagulants because of their small size and the difficulty in maintaining anticoagulation in children. One of these children died just as he was being placed on the operating table. Four adults had reoperation for pannus formation. Two definitely were not receiving anticoagulation and a third may not have been. Only one patient who was receiving regulated anticoagulation had pannus formation. There was only one late death in the mitral reoperation series of seven patients. In this patient a thrombosed Smeloff-Cutter prosthesis was replaced with a Hancock prosthesis. If we study these patients more carefully to determine their tendency toward thrombosis or normal coagulation, perhaps we can select patients that will be either low risk or high risk for thromboembolism and, therefore, determine the type of valve replacement required. DR. S Y R A C USE (Closing) I would like to thank each of the discussers for reviewing the data at their institutions and balancing them against our data. We are now constructing a data base for the assignment of risk to an increasingly large population of patients. Clearly, reoperations are better prevented than performed. Dr. Matloff raised questions regarding the specific valves we have used. The intent of our analysis was to emphasize the broad categories of disorders which affect valves in general irrespective of specific mechanical design. No valve has been free from problems requiring a reoperation at some time. The ball valves have been in wide use longer than others, and much of our analysis was drawn from reoperations on such valves. We now use the porcine xenograft in all positions for all valve replacements, but fully expect that as more experience accumulates, this too will have its detractors. Predominant aortic prostheses we have used and the reoperations required are as follows: 230 Starr-Edwards valves, 26 reoperations; 172 Hancock xenografts, three reoperations; 50 homografts, 13 reoperations; 40 Bjork-Shiley valves, two reoperations; and 94 Braunwald-Cutter valves, four reoperations. Incidentally, supported by this analysis of the prospect of low-risk reoperations at our institution, we have subsequently followed the lead of the groups at Alabama and the Mayo Clinic in replacing Braunwald-Cutter valves in view of projected poppet escape. To date 15 patients have come to purely elective replacement; all prostheses have shown severe cloth wear and most have shown poppet variance. Predominant mitral prostheses we have used and the reoperations required are as follows: 404 Starr-Edwards valves, 21 reoperations; 200 Hancock xenografts, one reoperation; and 41 Braunwald-Cutter valves, two reoperations. I would like to acknowledge Dr. Shumway's previous contribution. His paper published in 1966 is one of the first in the broad subject of repeat open-heart operation, and this recent updating from Stanford is most interesting.
The Journal of
354 Syracuse, Bowman, Maim
Dr. Smeloff, we have not used your valve so that I can make no comment, Dr. Grunwald, we have had similarly unimpressive complication rates at reoperation if early deaths are excluded. It seems that if those patients survive the reoperation, their hospital stay as well as other morbidity parameters are remarkably low. DR. MAL M (Closing) I want to comment on prevention or prophylaxis. In half of our infected valves, there was some identifiable episode in the follow-up period which was associated with the bacteremia. It is important to constantly reinforce with our patients the need
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for prophylaxis of antibiotics. Penicillin is inadequate prophylaxis. These patients should receive either cloxacillin or ampicillin and, if they are having a urologic procedure or even urethral catheterization, they should have gentamycin or kanamycin or some appropriate coverage. Probably the most difficult thing for us to identify is ball variance or pannus or thrombus around the prosthesis, particularly in patients with emboli. There is some interesting work going on now, not only with the M mode echo but with sector scanning, that might provide valuable information in evaluating these prostheses.
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