Pulmonary Valve Replacement Late After Repair of Tetralogy of Fallot

Transcription

1 Pulmonary Valve Replacement Late After Repair of Tetralogy of Fallot Ilya M. Yemets, MD, William G. Williams, MD, Gary D. Webb, MD, David A. Harrison, MD, Peter R. McLaughlin, MD, George A. Trusler, MD, John G. Coles, MD, Ivan M. Rebeyka, MD, and Robert M. Freedom, MD The Hospital for Sick Children and the Toronto Congenital Cardiac Centre for Adults, Toronto, ntario, Canada Background. Pulmonary valve incompetence is usually well tolerated after tetralogy of Fallot repair but may result in late progressive right heart failure as manifested by increasing fatigue, dyspnea, and frequently arrhythmias. Methods. All patients who underwent pulmonary valve replacement in our center late after repair of tetralogy of Fallot were reviewed. Results. Eighty-five patients had elective pulmonary valve replacement late (median, 9.3 years) after repair. perative risk was low (1.1%). Ninety percent of survivors are in New York Heart Association class I. Survival 1 years after pulmonary valve replacement is 95%, with 86% of the patients free of reoperation for valve failure. Conclusions. Pulmonary valve replacement is infrequently required after repair of tetralogy of Fallot. Pulmonary valve replacement may be performed electively with little risk; it improves symptoms of right heart failure and provides satisfactory long-term survival with low risk of early valve failure. As the population of patients who have had repair of tetralogy of Fallot ages, pulmonary valve replacement will become a more frequent consideration. (Ann Thorac Surg 1997;64:526-3) 1997 by The Society of Thoracic Surgeons he late results of repair of tetralogy of Fallot (TF) are T favorable in most patients, including those followed up into adulthood [1]. Approximately 5% of patients with tetralogy, however, require reoperation for residual lesions [2-5], including pulmonary valve insufficiency. Pulmonary insufficiency and right ventricular dysfunction, which are universally present to some degree after tetralogy repair, may be poorly tolerated if there are additional residual lesions [6-9]. Indeed, patients with isolated pulmonary valve insufficiency in hearts that are otherwise anatomically normal are usually asymptomatic until age 3 to years [1]. In patients with tetralogy, Redington's group [11, 12] has demonstrated that reduced right ventricular compliance may protect against the detrimental effects of pulmonary valve incompetence late after repair. Several recent reports [5, 11, 13, 14] correlate pulmonary insufficiency with right ventricular dilatation and reduced capacity for exercise. Increasing evidence [15-19] suggests that pulmonary valve insufficiency is associated with the development of arrhythmias and possibly with sudden death. We report the outcome of patients after tetralogy repair who required pulmonary valve replacement (PVR) at The Hospital for Sick Children, Toronto, and the Toronto Congenital Cardiac Centre for Adults. Accepted for publication March 3, Address reprint requests to Dr Williams, The Hospital for Sick Children, Suite 1525, 555 University Ave, Toronto, N M5G 1X8, Canada. Material and Methods Patients The database of the Division of Cardiovascular Surgery at The Hospital for Sick Children was searched for all tetralogy patients undergoing PVR at The Hospital for Sick Children or the Toronto Congenital Cardiac Centre for Adults; we found 95 patients who underwent PVR between 1969 and January We excluded 1 of these patients, all children, in whom PVR was undertaken urgently to salvage a child from critical low output syndrome in the early phase of postoperative recovery (within 24 days) of initial repair. We also excluded from this review 12 patients who had a PVR as part of their initial tetralogy repair (including 54 patients with tetralogy and absent pulmonary valve). We reviewed operative records of prior palliative procedures, initial repair, and PVR, including clinical status before PVR, the indications for PVR, and subsequent clinical course. Follow-up data (physical examination, electrocardiography, chest roentgenography, echocardiography, and sometimes [n = 11] cardiac catheterization) were available from our own outpatient clinics or from tertiary referral centers for all but 1 patient. Thirty-one (36%) of the patients are female; 54 are male. Mean age at the time of repair of TF was 8 years (range,.5 to years; median, 5.6 years). Forty-nine patients (58%) had a palliative operation preceding their repair, most commonly a Blalock-Taussig shunt (n = ). At the initial repair, right ventricular outflow tract obstruction was treated by transannular patch in 56 (66%) of the patients; the pulmonary valve annulus was preserved 1997 by The Society of Thoracic Surgeons /97/$17. Published by Elsevier Science Inc PII S3-4975(97)577-8

2 Ann Thorac Surg YEMETS ET AL ;64:526-3 PST-FALLT VALVE REPLACEMENT 25 3 Mean 8.1 years Range.5 to years Median 5.6 years Mean 11.6 years Range.4 to 36 years Median 9.3 years t- o o. 6 1 c >5 Age at tetralogy repair (years) Fig 1. Age at initial repair of tetralogy is illustrated for all 85 patients who subsequently under-went pulmonary valve replacement. Median age is 5.6 years. in 29 (34%). Anticoagulation was not recommended after PVR, but patients were encouraged to take low-dose long-term acetylsalicylic acid. Statistical Analysts Survival data were analyzed using the Kaplan-Meier method (Statistica, Version 5; Softstat Inc, ). Indication for Pulmonary Valve Replacement Most patients have pulmonary insufficiency after TF repair and tolerate it for many years. However, in a previously stable patient, the onset of symptoms, usually fatigue and dyspnea, and the development of arrhythmias, either ventricular tachycardia or supraventricular tachycardia, or the onset of tricuspid insufficiency are clinical indications for consideration of PVR. A total of 85 patients had PVR at a time remote from their initial repair. Their age at initial repair is shown in Figure 1. At the time of their PVR, their mean age was 19.6 years (range, 2 to 54 years; median, 15.4 years) (Fig 2). cl Mean 19.6 years >5 Age at PVR (years) Fig 2. Age at pulmonary valve replacement (PVR) late after tetralogy repair varied from 2 to 54 years with a median qf 15.4 years >5 Time from tetralogy repair (years) Fig 3. Time interval from initial repair to puhnonary valve replacement varied from.4 to 36 years with a median of 9.3 years. Mean time from repair to PVR is 11.6 years (range,.4 to 36 years; median, 9.3 years) (Fig 3). These patients usually presented with diminished tolerance for exercise and evidence of progressive right ventricular enlargement leading to tricuspid insufficiency. Nineteen had presyncope or syncope from episodic ventricular tachycardia (VT). Thirteen underwent cryoablation of an arrhythmogenic ventricular focus concomitant with the PVR. An additional patient who presented with VT 17 years after PVR underwent mapping, cryoablation, and replacement of his stenotic prosthetic pulmonary valve. In 29 patients, PVR was an isolated procedure. In the other 56 patients (66%), additional procedures were required: closure of the residual ventricular septal defect (n = 13), cryoablation of arrhythmia (n = 13), branch pulmonary arterioplasty (n = 3), and miscellaneous procedures in 25 (aortic valve replacement, 2; mitral valve repair, 3; tricuspid valve repair, 6; atrial septal defect, 9; and others, 5). In addition, most patients had dilatation of the right ventricular outflow tract incision or patch, and this was plicated during the PVR operation. Methods We used two types of devices to replace the pulmonary valve. Six patients had a valved conduit (porcine/dacron in 3, pulmonary homograft in 2, Polystan in 1), and in 79, we sewed a prosthetic valve into the pulmonary annulus and covered it with a pericardial patch. The pericardial patch extended from the pulmonary artery bifurcation onto the right ventricular infundibulum; we referred to this technique as a pulmonary valve implant. Among the patients with a pulmonary valve implant, had a porcine valve, 36 a pericardial valve, and 3 some other type. We performed all PVR operations through a median sternotomy with cardiopulmonary bypass and hypothermia (32 to 35 C). Aortic cross-clamping was used only when required to facilitate the intracardiac repair of associated lesions. Femoral artery/vein cannulation was used to initiate bypass before sternotomy, if required to prevent or control bleeding.

3 528 YEMETS ET AL Ann Thorac Surg PST-FALLT VALVE REPLACEMENT 1997;64:526-3 > U) patients mean follow-up 5.8 years 1 early death 3 late deaths N = Fig 4. Patient survival after pulmonary valve replacement is illustrated for all 85 patients, with a mean.follow up of 5.8 years. The dotted line indicates the 95% conyqdence interval. The number of patients at risk entering each time period after valve replacement is indicated by N =. Results f 85 patients who underwent PVR between 1969 and 1997 after previous repair of TF, 1 (1.1%) died during the immediate postoperative period (within 1 month). The one operative death occurred in a 5-year-old child who underwent PVR, closure of a residual ventricular septal defect, and mitral valve replacement 18 months after initial tetralogy repair. The postoperative course in the other patients was generally uneventful. No complications related to the PVR were observed in the early postoperative period. Anticoagulants were not prescribed. Low-dose acetylsalicylic acid, three times per week, was recommended. The surviving patients have been followed up from 1 month to 26 years postoperatively (mean follow-up, 5.8 years). There have been three late deaths. The actuarial survival is 95% + 3% at 1 years and 87% _+ 8% at 15 years (Fig 4). The late deaths were not related to the PVR. A 4-yearold patient died 4 months after PVR of respiratory infection and sepsis; autopsy found that a residual ventricular septal defect was present. Another fatality was caused by a motor-vehicle accident 1 years after PVR. The third late death occurred suddenly at home 5.9 years after PVR in a patient who had been classified as New York Heart Association class I. He had a history of drug abuse. After his TF repair at age 3.8 years, he presented with VT and underwent PVR at age 16.2 years. Although VT was present before PVR, it was multifocal, and neither intraoperative electrophysiologic studies nor cryoablation was performed. Preoperative VT was observed in 19 patients, but at intraoperative electrophysiologic mapping, it was inducible and monomorphic in only 13, all of whom underwent arrhythmia ablation during the PVR. f the others, the arrhythmia could not be induced at operation in 1 patient, the arrhythmia was localized to the left ventricular endocardium and ablation was not attempted in another, and VT was multifocal in the remaining 4 patients. Survival of the 19 patients presenting with VT did not differ statistically from that of the 66 patients without documented preoperative VT. The time from initial repair to PVR is a mean of 13.3 years for patients with no associated lesions versus 1.7 years for those with other lesions, a difference that is not statistically significant. Similarly, the age at PVR was not different among patients with isolated pulmonary insufficiency compared with those with associated lesions. Symptoms improved after PVR in most patients. The functional status of all surviving patients at the time of late follow-up is compared with their status before PVR in Figure 5. However, as the prosthetic valve fails, one expects their functional status will deteriorate. Sixty-five percent of these patients had their initial tetralogy repair before 198, when the mean age at repair was 9.7 years. In the more recent era, the age for tetralogy repair has decreased; it has been 5.1 years since 198 and 3.2 years from 1985 to At the same time, the age at PVR in these different eras is increasing from 12 years before 198 to a mean of 21 years since During the follow-up period of observation, 8 patients have required replacement of their prosthetic pulmonary valve, a mean of 8.9 years (range, 3.4 to 16.9 years) after PVR. By actuarial analysis, 86% -+ 7% of patients are free of reoperation 1 years after valve replacement (Fig 6). The analysis of survival free of reoperation for porcine (n = ) versus pericardial pulmonary valve implants (n = 36) reveals no statistically significant difference, but the trend suggests that with longer follow-up the porcine valve will prove to be more durable (Fig 7). Comment Some degree of pulmonary valve incompetence is almost universal after tetralogy repair. In the absence of important residual lesions such as right ventricular outflow tract stenosis, pulmonary artery branch stenosis, or residual ventricular septal defect, pulmonary incompe- 1% 75% 5% 25% %! I r NYHA Classification Fig 5. Functional class of patients before and after valve replacement is indicated. Ninety percent of patients are in New York Heart Association (NYHA) class I after valve replacement.

4 Ann Thorac Surg YEMETS ET AL ;64:526-3 PST-FALLT VALVE REPLACEMENT e- o n" ~ 4 U,. N 2 85 patients... 8 valve reoperatlons N = Fig 6. Interval free of reoperation for valve failure is plotted by Kaplan-Meier analysis. The dotted lines indicate the 95% conj~dence intervals of survival, and the number of patients at risk for each time period are indicated by N =. tence is generally tolerated well for many years [6-9]. Recent data suggest that pulmonary incompetence is especially well tolerated late after repair in patients with restrictive diastolic performance [11]. In our series of 85 patients requiring pulmonary valve replacement after tetralogy repair, only 29 patients (34%) experienced isolated pulmonary insufficiency. Indeed, in the rare situation of patients with anatomically normal hearts with absent pulmonary valve, Shimazaki and coworkers [1] reported that symptoms were rare before the age of 3 years. However, beyond age 3 to years, progressively more patients had increasing fatigue and dyspnea and the onset of right heart failure. It seems probable that tetralogy patients with pulmonary valve insufficiency will be become symptomatic at a younger age than patients with otherwise anatomically normal hearts. As a corollary, one should expect an increasing number of patients after tetralogy repair to present with progressive right heart failure caused by pulmonary valve insufficiency as they approach middle age--or younger, if they have additional lesions, although the time from repair to pulmonary valve replacement was not significantly different in the subset of patients with additional lesions. It is difficult to estimate the total number of patients with tetralogy repair from which these 85 patients were selected for PVR. Approximately 5 patients per year undergo tetralogy repair at our center. Some PVR patients were referred from other centers. As a best estimate, 1.2% of our institutions' patients with repair of tetralogy have undergone PVR. Because the need for PVR after tetralogy repair is time-dependent, with progressively more patients considered for the procedure years after repair, the estimated average of 1.2% greatly understates the long-term risk. Changing techniques in tetralogy repair and the decreasing age at repair should have a favorable influence on both the need and timing for PVR, but these effects are not evident as yet. i There is a known risk of late sudden death due to ventricular arrhythmias after tetralogy repair [15-19]. The association of ventricular arrhythmias with suboptimal hemodynamics in patients with tetralogy has been addressed by our group [16]. We hypothesize that improving right heart function by implanting a competent pulmonary valve may decrease the chance of fatal arrhythmias. We have only 19 patients in this series with VT. ne late, presumed arrhythmic sudden death occurred in a patient who presented with multifocal ventricular tachycardia. Because of its multifocal origin, ablation of the arrhythmia was not attempted in this patient during PVR. We previously reported our experience with ablation therapy after tetralogy repair, but the data are not yet sufficient to support firm conclusions []. The indications for choosing among ablation, medication, implantable defibrillator therapy, or simply improving the hemodynamic status with PVR remain to be clarified. In this series, there is no difference in survival for patients presenting with VT (n = 19) compared with those without (n = 66), and overall, survival is 95% at 1 years after PVR. We do not have data to demonstrate the hemodynamic improvement that occurs with pulmonary valve replacement. Many authors have published objective evidence of improved cardiac performance after PVR [14, 21, 22]. Among our patients, the subjective improvement reported was considerable (see Fig 5), suggesting a favorable hemodynamic response to PVR. Exercise capacity will diminish, however, as the prosthetic valve deteriorates. We are currently collecting cardiopulmonary exercise data prospectively to clarify the changing functional abilities in these patients. Pulmonary valve replacement late after tetralogy repair can be performed at low operative risk (1.1%) with good intermediate-term survival (95% at 1 years after replacement) and with reasonably good long-term durability of the valve (86% free of reoperation at 1 years). c~ LL Porcine i I p n.s. t Pericardial i t N = N = Fig 7. Survival free of reoperation for patients with porcine valves compared with 36 pericardial valves is portrayed. There is no statistically significant difference (n.s.) in survival. The number of patients with valves at risk for each time period is indicated by N.

5 53 YEMETS ET AL Ann Thorac Surg PST-FALLT VALVE REPLACEMENT 1997;64:526-3 We have previously reported that multivariate analysis demonstrates that both older age at PVR and use of a larger valve improve valve longevity but not valve type. We anticipate that a porcine prosthesis will be the most durable valve, but to date there is no statistically important difference compared with the pericardial valve (see Fig 7). Intracardiac repair of patients with tetralogy of Fallot should be carefully done to ensure a minimum of residual hemodynamic lesions. Pulmonary valve replacement is rarely necessary. When right heart failure does develop after tetralogy repair, our data show that PVR and repair of associated lesions can be undertaken safely, with good long-term improvement, albeit at the inevitable cost of future operations to replace the prosthetic valve. References 1. Waien SA, Liu PP, Ross BL, Williams WG, Webb GD, McLaughlin PR. Serial follow-up of adults with repaired tetralogy of Fallot. J Am Coll Cardiol 1992;: Lillehei CW, Warden HE, DeWall RA, et al. The first openheart corrections of tetralogy of Fallot: a year follow-up of 16 patients. Ann Surg 1986;4: Fuster V, McGoon DC, Kennedy MA, Ritter DG, Kirklin JW. Long-term evaluation (12 to 22 years) of open-heart surgery for tetralogy of Fallot. Am J Cardiol 198;46: hao HX, Miller DC, Reitz BA, Shumway NE. Surgical repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 1985;89: Murphy JC, Gersh BJ, Mair DD, et al. Long-term outcome in patients undergoing surgical repair of tetralogy of Fallot. N Engl J Med 1994;329: Ilbawi MN, Idriss FS, DeLeon SY, et al. Factors that exaggerate the deleterious effects of pulmonary insufficiency on the right ventricle after tetralogy repair. J Thorac Cardiovasc Surg 1987;93: Finck SJ, Puga FJ, Danielson GK. Pulmonary valve insertion during reoperation for tetralogy of Fallot. Ann Thorac Surg 1988;45: Kirklin JK, Kirklin JW, Blackstone EH, Milano A, Pacifico AD. Effect of transannular patching on outcome after repair of tetralogy of Fallot. Ann Thorac Surg 1989;48: Jonsson H, Ivert T, Jonasson R, Holmgren A, Bj/Srk V. Work capacity and central hemodynamics thirteen to twenty-six years after repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 1995;11: Shimazaki Y, Blackstone EH, Kirklin JW. The natural history of isolated congenital pulmonary valve incompetence: surgical implications. J Thorac Cardiovasc Surg 1984;32: Gatzoulis MA, Clark AL, Cullen S, Newman CG, Redington AN. Right ventricular diastolic function 15 to 35 years after repair of tetralogy of Fallot. Circulation 1995;91: Cullen S, Shore D, Redington A. Characterization of right ventricular diastolic performance after complete repair of tetralogy of Fallot. Circulation 1995;91: Rocchini AP, Rosenthal A, Freed M. Chronic congestive heart failure after repair of tetralogy of Fallot. Circulation 1977;56: Warner KB, Anderson JE, Fulton DR, Payne DD, Geggel RL, Marx GR. Restoration of the pulmonary valve reduces right ventricular volume overload after previous repair of tetralogy of Fallot. Circulation 1993;88(Suppl 2): Quattlebaum TB, Varghese J, Neill CA, Donahue JS. Sudden death among postoperative patients with tetralogy of Fallot. Circulation 1976;54: Burns RJ, Liu PP, Druck MN, Seawright SJ, Williams WG, McLaughlin PR. Analysis of adults with and without complex ventricular arrhythmias after repair of tetralogy of Fallot. J Am Coil Cardiol 1984;4: Gatzoulis MA, Till JA, Somerville J, Redington AN. Mechanoelectrical interaction in tetralogy of Fallot. QRS prolongation relates to right ventricular size and predicts malignant ventricular arrhythmias and sudden death. Circulation 1995; 92: Dietl CA, Cazzaniga ME, Dubner SJ, Perez-Balino NA, Torres AR, Favaloro RG. Life threatening arrhythmias and RV dysfunction after surgical repair of tetralogy of Fallot. Circulation 1994;9: Downer E, Harris L, Kimber S. Ventricular tachycardia after surgical repair of tetralogy of Fallot: results of intraoperative mapping studies. J Am Coll Cardiol 1992;: Ebert PA. Second operations for pulmonary stenosis of insufficiency after repair of tetralogy of Fallot. Am J Cardiol 1982;5: Bove EL, Kavey RW, Byrum CJ, Sondheimer HM, Blackman MS, Thomas FD. Improved right ventricular function following late pulmonary valve replacement for residual pulmonary insufficiency or stenosis. J Thorac Cardiovasc Surg 1985; 9: Ilbawi MN, Idriss FS, DeLeon SY, Muster AJ, Berry TE, Paul MH. Long-term results of porcine valve insertion for pulmonary regurgitation following repair of tetralogy of Fallot. Ann Thorac Surg 1986;41: