Ross procedure in congenital patients: Results and left ventricular function 1

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1 European Journal of Cardio-thoracic Surgery 11 (1997) Ross procedure in congenital patients: Results and left ventricular function 1 J.E. Rubay a, *, P. Shango b, S. Clement c, C. Ovaert b, A. Matta d, A. Vliers b, Th. Sluysmans b a Department of Cardiac Surgery, UCL St-Luc, 10 a enue Hippocrate, 1200 Brussels, Belgium b Department of Pediatric Cardiology, UCL St-Luc, 10 a enue Hippocrate, 1200 Brussels, Belgium c Department of Pediatric Intensi e Care, UCL St-Luc, 10 a enue Hippocrate, 1200 Brussels, Belgium d Department of Anesthesiology, UCL St-Luc, 10 a enue Hippocrate, 1200 Brussels, Belgium Received 5 October 1995; revised 28 March 1996; accepted 25 April 1996 Abstract Methods: From April 1990 to August 1995, 121 patients (median age 42 years) underwent aortic valve replacement with allografts (69 patients) or autografts (52 patients). In this latter group, 24 Ross procedures have been performed in congenital patients since November 1991 (median age 10 years, range five months to 27 years): aortic incompetence (n=17), isolated aortic stenosis (n=5), small stenotic prosthesis (n=2). Transthoracic echocardiography was obtained preoperatively in all patients and serially after surgery with the aim of measuring aortic and pulmonary annuli and evaluate gradients and incompetence and to study the left ventricular function. Intraoperative transoesophageal echocardiography was routinely used. Complete root replacement was performed in all patients. Results: One patient died in the early postoperative period (4%). There was no late death. All survivors remained in NYHA class I and were free of complications and medications. No gradient nor any significant aortic incompetence could be demonstrated. In 17 patients with predominant aortic incompetence before surgery, the left ventricular function was followed prospectively, end-diastolic left ventricular dimensions diminished drastically from S.D. above normal to S.D. at one week postoperatively (day 10) to reach a normal value one to three months after surgery. Left ventricular mass remained abnormal at day 10 (from S.D. to S.D.) and diminished more progressively to reach a normal value ( S.D.) at three months. This resulted in a significant decrease of end-systolic wall stress ( S.D.) and in a hyperdynamic function in the immediate postoperative days except in two patients. These two patients were characterized preoperatively by more severely dilated left ventricle (end diastolic dimension versus S.D.) with decreased left ventricular wall thickness ( versus S.D.), decreased ratio between end diastolic wall thickness and end diastolic dimension ( versus ) and a decreased velocity of shortening. Unlike the other 15 patients, the left ventricular function did not recover completely at mid term follow-up in those two patients. Conclusion: The Ross operation is a safe procedure and allows us to suppress completely the abnormal loading conditions of the left ventricle, resulting in a complete recovery of left ventricular function in most patients. Copyright 1997 Elsevier Science B.V. Keywords: Pulmonary autograft; Aortic valve disease; Congenital heart disease; Left ventricular function; Allograft 1. Introduction * Corresponding author. Tel.: ; fax: Presented at the Ninth Annual Meeting of the European Association for Cardio-thoracic Surgery, Paris, France, September, There is a quest toward the identification of the ideal substitute for the diseased aortic valve in children and young adults. The use of anticoagulants and the risks of sudden death, thromboembolism, hemorrhage and infection with prosthetic valves remain of concern [6]. Porcine /97/$17.00 Copyright 1997 Elsevier Science B.V. All rights reserved PII S (96)

2 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) bioprostheses deteriorate rapidly in young patients and have limited durability [1]. In 1967, Ross [18] described the use of the autologous pulmonary valve to replace the diseased aortic valve. These viable valves have a potential for growth [8,10], a particular advantage in children. Optimal hemodynamic function should be reached with these valves [15] and the feared prosthetic valves complications be avoided [14]. In this report, we describe our experience in replacing the diseased aortic valve with a pulmonary autograft as a root in 24 patients and the results of serial echocardiographic studies assessing the left ventricular function in most of them. 2. Material and methods 2.1. Patients Between November 1991 and August 1995, amongst the 52 patients who had a Ross procedure, we have selected those 24 congenital patients who underwent replacement of the aortic root with a pulmonary autograft. The patients ranged in age from 5 months to 28 years (mean 11.8). There were 14 males and 9 females. Five patients were operated on for aortic stenosis, 16 for aortic regurgitation, 2 patients had small stenotic prosthesis and 1 patient had degeneration of his allograft with incompetence, 3 years after implantation (Table 1). Previous procedures and operations are listed in Table 2. They all had measurement of the diameter of both aortic and pulmonary annuli and assessment of the pulmonary valve competence by transthoracic 2D Doppler echocardiography. The 17 patients with predominant aortic incompetence had prospective assessment of their LV function. Serial follow-up transthoracic echocardiograms (TTE) were obtained in all survivors at 10 days, 1 month, 3 months, 6 months, 1 year and every year thereafter for assessment of residual valve stenosis and regurgitation. All examinations were performed by use of the ACUSSON 128 X P 10 echocardiographic system. Pulsed- and continuous-wave Doppler was used to measure peak and mean aortic valve gradients and to calculate valve areas. Doppler color flow mapping was used to assess the presence and extent of aortic regurgitation. The severity of regurgitation was evaluated qualitatively on a 4 point-scale from 0 (absent) to 4 (severe). LV function was evaluated prospectively in the patients with significant aortic incompetence before surgery. Table 1 Indications for operation Aortic incompetence Isolated 3 With stenosis 7 Post commissurotomy or balloon dilatation 5 Associated with VSD 1 Degeneration of allograft 1 Total number of patients 17 Patients with aortic stenosis 5 Patients with small stenotic prosthesis 2 Standard short- and long-axis views of the LV were recorded to assess regional wall motion. In addition, in patients with a circular LV in short-axis views and no evidence of regional wall motion abnormalities, a highspeed (100 mm/s) two-dimensional directed M-mode recording of the LV minor axis with simultaneous ECG, phonocardiogram, and indirect carotid pulse tracing was recorded for quantitative analysis. Systolic and diastolic blood pressures were obtained using a DYNAMAP 845 vital signs monitor. The hospital records and catheterization reports of each patient were reviewed M mode analysis of LV dimensions, thickness and stress The pulse tracing, the anterior and posterior LV endocardial borders and the epicardial border of the LV posterior wall were hand digitized with a microcomputer-based digitizing station with custom software. End-systolic pressure was calculated from the calibrated pulse tracing as previously described [2,17]. The LV long axis dimension was measured from apical two-dimensional echocardiographic images at end diastole and at end systole. From the digitized data, the following measurements were obtained throughout ejection by averaging three cardiac cycles: LV short-axis diameter, LV posterior wall thickness, and LV pressure. End-systolic LV meridional wall stress (ESSm) and LV circumferential wall stress (ESSc) were calculated. The LV fractional shortening (FS) was calculated as (EDD-ESD)/EDD where EDD is end-diastolic short- Table 2 Previous procedures and operations Procedures/operations Aortic valvotomy 1 Mechanical 2 Aortic valve replacement allograft 1 Aortic balloon valvuloplasty 4 Patients

3 94 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) axis dimension and ESD is end-systolic short-axis dimension. LV ejection time was measured from the pulse tracing and adjusted to a heart rate of 60 beats/min by dividing by the square root of the RR interval of the ECG. The rate-adjusted mean velocity of shortening (VCFc) was calculated as FS divided by the rate adjusted ejection time. The sphericity of the ventricle was calculated as the ratio between the major and minor LV axis in diastole (diastolic shape index) and in systole (systolic shape index) Indexes of contractility and preload The relation between VCFc and the end systolic wall stress (meridional wall stress (ESS m ) and circumferential wall stress (ESS c )) has been shown previously to be indexes of contractility that are relatively independent of preload and incorporates afterload [3]. The value of the ESSc VCFc relation (stress velocity index, SVIc) and of the ESSm VCFc (SVIm) for each patient was determined relative to the previously reported distribution of this index in normal subjects 1 19 years old [4] and expressed as the normal deviate or Z score (the number of standard deviations from the population mean VCFc for the ESSc). In contrast, the relation between FS and end systolic wall stress (stress-shortening index, SSIc and SSIm) are an afterload-adjusted index of contractility that are also sensitive to alterations in preload [5]. The SSIm and SSIc were also determined relative to the normal range for our laboratory and expressed in the Z score. The difference in the Z score of the SSIm and SVIm was determined as the functional preload index [5] (FPIm=SSIm SVIm), reflecting the fact that FS is related to end-diastolic fiber stretch (preload), whereas VCFc is not. The difference between the ESSm FS relation (SSIm) and the ESSm VCFc relation (SVIm) therefore reflects the functional consequences of altered preload Operati e technique All patients were operated through a median sternotomy. The aortic and pulmonary roots were extensively dissected out. Extracorporeal circulation was instituted in the usual fashion using two venous drainage canulae. Moderate hypothermia (25 ) and topical cooling of the heart with cold saline solution were used. During the period of myocardial ischemia, which averaged 132 min (range ), the myocardium was protected by the infusion of cold crystalloid cardioplegia directly into the coronary ostia or in a retrograde fashion into the coronary sinus and repeated after one h. The pulmonary root was transected proximal to the Fig. 1. Dissection of the proximal site of the pulmonary trunk. The right infundibulum is opened a few mm below the sinuses of valsalva, taking care to avoid the first septal branch. AO, aorta; PA, pulmonary autograft; LM, left main coronary artery; SP, septal branch (arrow); RV, right ventricle. bifurcation and dissected down to the septum. At the proximal site, the right infundibulum was opened a few millimetres below the sinuses of valsalva with a ridge of right ventricular muscle, taking care to avoid the first septal branch (Fig. 1). 24 pulmonary allografts were implanted as pulmonary root with a mean diameter of 23 mm (range 16 28). The pulmonary autograft root was secured on a horizontal plane at aortic annular level, crossing the anterior septal leaflet of the mitral valve and the membranous septum (Fig. 2), very superficially, and using continuous running sutures of 5.0 polypropylene in infants or interrupted 4.0 polypropylene in children and young adults (Fig. 3). The coronary orifices were excised with a button of aortic wall and reimplanted in the corresponding sinuses of valsalva using a continuous 6.0 or 7.0 polypropylene. The autograft was anastomosed to the ascending aorta with 6.0 or 5.0 polypropylene. The pulmonary suture lines were sealed with fibrin glue. Four concomitant procedures were performed, one VSD closure, one Konno procedure, one aortic arch enlargement and one mitral valvuloplasty. After wean-

4 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) ing of the bypass, the competence of the autograft valve was assessed by transoesophageal echocardiography (TEE) in 21 patients Statistical analysis Student s t-test was used to analyse unpaired data for continuous variables. All test were two-tailed and P 0.05 were considered indicative of a statistically significant difference. The results are presented as mean S.D. unless otherwise specified. 3. Results Mean aortic cross clamping time was 132 min (range min). One patient with associated supravalvular aortic stenosis after aortic arch repair died peroperatively from bleeding and subsequent electro-mechanical dissociation in an attempt to mobilize the heart (4%). Peroperative TEE was normal in all but 4 patients who presented with trivial (grade 1) in 3 and trivial to mild (grade 1/2) aortic incompetence. One patient had to be reoperated on for delayed bleeding (one week). The mean follow-up period was 12.6 months (range 1 47 months). There has been no late death nor endocarditis, thromboembolic events and reoperations. No anticoagulation therapy was used. The patients were given Dipyridamole and aspirin for 1 month. All survivors were in class I of the NYHA at last follow-up Echocardiographic findings There was no significant gradients on aortic valve. Two patients presented with moderate gradients on the right outflow tract (28 mmhg and 40 mmhg respectively). Two patients had trivial to mild (grade 1/2) aortic incompetence, 12 patients had trivial or grade 1 and 9 patients had no aortic incompetence. Four patients had grade I pulmonary incompetence. The mean values for annular diameter of the autograft soon after the operation and at the most recent follow-up visit was as follows: 19 3 mm as compared with 20 4 mm. These differences were not statistically significant. In 5 patients, a dilatation ranging from 4 to 8 mm of the neo-aortic annulus was noticed, associated in 1 with the occurrence of a trivial aortic incompetence (from 0 to 1). Amongst the 17 patients with predominant aortic incompetence, all had normal or supranormal shortening fraction (above 33%) before surgery. However 6 patients had reduced LV function characterised by a decreased SVIm and an elevated preload (FPIm). Amongst them, 4 returned to normal postoperatively and 2 remained abnormal 3 months postoperatively with low shortening fraction (Fig. 4). The factors affecting significantly the probability of maintaining LV dysfunction were the duration of the disease (more than 5 years), the grade of aortic incompetence (grade 4), more dilated left ventricles (EDD Z S.D. US S.D.), insufficient myocardial hypertrophy (EDWT Z +2 S.D. with low EDWT/EDD ratio), a lowered velocity of circumferential fiber (VCFc 0.9 cm/s), a spherical shape (diastolic shape 1.3) and a reduced circumferential stress velocity index (SVIc 2 S.D.). Before surgery, all except 3 patients had normal contractility index (Fig. 5). Two of these patients remained with abnormal low contractility after surgery, explaining the abnormal shortening fraction observed in those 2 patients after surgery. 4. Discussion Fig. 2. The pulmonary autograft root is secured on a horizontal plane (dotted line). RC, right coronary artery; LC, left coronary artery; MS, membranous septum; MV, anterior leaflet of mitral valve; OS, outlet septum. Since its introduction in 1967 by Ross [18] and the different technical modification, e.g. the use of an intraluminal cylinder and the root replacement technique [19,20], there has been a recent increase in interest in

5 96 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) Fig. 3. The pulmonary autograft root is anastomosed to the aortic annulus using interrupted sutures (children and young adults); PA, pulmonary autograft; RC, right coronary artery; LC, left coronary artery. pulmonary autograft replacement for the diseased aortic valve [7,13,16]. In children and young adult with aortic valve disease, no satisfactory alternative is available. Surgery was often delayed as long as possible, and sometimes too long, with permanent left ventricular damage. Homografts have limited durability and might require reoperation. This was the reason for operation in one of the patients in our series. Although the Ross procedure is a longer and more complex procedure than prosthetic valve replacement, it has been demonstrated to be safe [9,13,16]. In our series, the hospital mortality was low (4%). Complications after mechanical valve replacement even with excellent hemodynamic profile are of concern. Serious fatal thromboembolic events and bleeding occurred in 0.7 and 1.3% of patients per year, respectively [14]. Including minor events, 2% of the patients experienced serious or fatal valve-related thromboembolic or anticoagulation related bleeding complications each year and 6.7% of patients had some degree of this kind of problem each year. There has been no thromboembolic event nor endocarditis in this series. No patient had to be reoperated. Fig. 4. Evolution of the LV shortening fraction before surgery (PRE) and 10 days (D10), 30 days (D30), 90 days (D90) after surgery. The normal range is represented by the oblique lines pattern area. The mean value (%) and individual s variation are indicated. Fig. 5. Evolution of the LV contractility index before surgery (PRE) and 10 days (D10), 30 days (30D), 90 days (90D) after surgery. The normal ranges are indicated by the oblique pattern area. The mean values and individual s variation are indicated.

6 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) Like others [9,16], we believe that the main concern regarding the use of pulmonary autograft in the aortic position is the potential for dilatation of the wall of the pulmonary artery and the subsequent development of valvular incompetence of the neo-aortic valve, as root replacement is the only suitable technique in pediatric patients. Experimental studies [12] have demonstrated the superior tensile strength of the leaflets of the pulmonary valve as compared to the aortic valve. Previous reports of echocardiographic enlargement of the pulmonary autograft have suggested that this enlargement represented growth [9,11]. It has been confirmed by Elkins et al. [8] for the intraaortic cylinder. For root replacement, their data strongly suggest dilatation even though there was only one incidence of associated insufficiency. Their data support the concept that this dilatation is mostly secondary to growth. The issue of possible dilatation and subsequent valve dysfunction in pulmonary autograft root replacements in children needs longer follow-up studies and continued careful evaluation. The fate of the pulmonary allograft seems to be of lesser concern since pulmonary incompetence is well tolerated as we know from repair of Tetralogy of Fallot and is not life-threatening, as long as the right ventricle does not dilate. Our main interest in this study has focused on the fate of the LV function before and after the Ross procedure. As the predominant indication for operation was aortic incompetence or aortic disease, it is not surprising to find increased volumes and increased shortening fraction. The shortening velocity index was normal in all but 6 patients. Postoperatively, the reduced preload accounts for the reduced volume and the reduced shortening fraction. As the mass does not change, the thickness increases and mass involution is delayed (more than 30 days) as well as normalization (more than 90 days). Two patients amongst the six who had abnormal function preoperatively remain abnormal. They both had major aortic incompetence, dilated left ventricles, insufficient myocardial hypertrophy, a lowered velocity of myocardial fibers and a spherical shape. When it happens, pulmonary stenosis, mainly at the site of the distal anastomosis, is more embarrassing if progressing. In order to avoid these disappointing results, cryopreserved allografts should be advocated and multiple continuous suture lines should be used. Root replacement with pulmonary autograft can be performed in infants, children and young adults with congenital aortic disease with low mortality and morbidity. Dilatation of the neo-aortic valve does not seem to be associated with increasing incidence of aortic incompetence but longer follow-up are needed before root replacement can be recommended as the operation of choice in this particular setting of patients. In the presence of significant aortic incompetence, it seems advisable to operate early in order to avoid the deleterious effect of a long standing increased preload on the LV function. In such cases, a precise evaluation of LV function is useful; shortening fraction is preload dependant and will remain normal even in the presence of severely impaired contractility. By comparison, the end-systolic stress velocity of shortening relationship, obtained from non invasive measurements is an adequate index of contractility and its evaluation would allow to recognize early on the deterioration of LV function in aortic incompetence. References [1] Al Khaja N, Belboul A, Rashid M et al. The influence of age on the durability of Carpentier-Edwards biological valves: thirteen years follow-up. Eur J Cardiothorac Surg 1991;5: [2] Colan SD, Borow KM, Mac Pherson D, Sanders SP. Use of the indirect axillary pulse tracing for noninvasive determination of ejection time, upstroke time, and left ventricular wall stress throughout ejection in infants and young children. Am J Cardiol 1984;53: [3] Colan SD, Borow KM, Neumann A. Left ventricular end-systolic wall stress-velocity of fiber shortening relation: a load independent index of myocardial contractility. J Am Coll Cardiol 1984;4: [4] Colan SD, Sanders SP, Parness IA, Spevak PJ. Evidence of enhanced contractility in normal infants compared to older children and adults. Abstract J Am Coll Cardiol 1989;13:135A. [5] Colan SD, Sanders SP, Ingelfinger JR, Harmon W. Left ventricular mechanics and contractile state in children and young adults with end-stage renal disease: effect of dialysis and renal transplantation. J Am Coll Cardiol 1987;10: [6] Edmunds LH Jr. Thrombotic and bleeding complications of prosthetic heart valves. Ann Thorac Surg 1987;44: [7] Elkins RC, Knott-Craig CJ, Randolph JD et al. Medium-term follow-up of pulmonary autograft replacement of aortic valves in children. Eur J Cardiothorac Surg 1994;8: [8] Elkins RC, Knott-Craig CJ, Ward KE, Mc Cure C, Lane MM. Pulmonary autograft in children: realized growth potential. Ann Thorac Surg 1994;57: [9] Elkins RC, Santangelo K, Randolph JD et al. Pulmonary autograft replacement in children: the ideal solution? Ann Surg 1992;216: [10] Gerosa G, Mc Kay R, Davies J, Ross DN. Comparison of the aortic homograft and the pulmonary autograft for aortic valve or root replacement in children. J Thorac Cardiovasc Surg 1991;102: [11] Gerosa G, Mc Kay R, Ross DN. Replacement of the aortic valve or root with a pulmonary autograft in children. Ann Thorac Surg 1991;51: [12] Gorczynski A, Trenkner M, Anisimowicz L et al. Biomechanics of the pulmonary autograft valve in the aortic position. Thorax 1982;37: [13] Hokken RB, Bogers AJ, Trams MA et al. Aortic root replacement with a pulmonary autograft. Eur J Cardiothorac Surg 1995;9: [14] Horstkotte D, Schulte H, Bircks W, Strauer B. Unexpected finding concerning thromboembolic complications and anticoag-

7 98 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) ulation after complete 10 year follow-up of patients with St-Jude medical prostheses. J Heart Valve Dis 1993;2: [15] Jaffe WM, Coverdale HA, Roche AHG, Whitlock RML, Neutze JM, Barrath-Boyes B. Rest and exercise hemodynamics of 20 to 23 mm allograft, Medtronic Intact (porcine) and St-Jude Medical valves in the aortic position. J Thorac Cardiovasc Surg 1990;100: [16] Kouchoukos NT, Davila-Roman VG, Spray TL, Murphy S, Perillo J. Replacement of the aortic root with a pulmonary autograft in children and young adults with aortic-valve disease. New Engl J Med 1994;1: [17] Rein AJ, Sanders SP, Colan SD, Parness IA, Epstein M. Left ventricular mechanics in the normal newborn. Circulation 1987;76: [18] Ross DB. Replacement of aortic and mitral valves with a pulmonary autograft. Lancet 1967;2: [19] Ross DN. Aortic root replacement with a pulmonary autograft current trends. J Heart Valve Dis 1994;3: [20] Rubay JE, Raphael D, Sluysmans Th et al. Aortic valve replacement with Allograft/Autograft: subcoronary implantation versus intraluminal cylinder or root. Ann Thorac Surg 1995;60: Appendix A. Conference discussion Dr E. Bos (Rotterdam, The Netherlands): You have stated the age of the patients from 5 months to 22 years. How many were under the age of one year, or, say, even less? Dr J. E. Rubay: There is only one under the age of one year. Dr E. Bos: And the majority? Dr J. E. Rubay: The majority was within 4 to 15 years old. Dr E. Bos: Four to 15. You did not mention, I think, even in the abstract, what happened before the operation. Were they ballooned, because I note that you have quite a number of patients with insufficiency. Dr J. E. Rubay: Three patients with critical aortic stenosis had been ballooned before the operation with subsequent aortic incompetence. The cardiologists have been waiting until we could do something better than a replacement by a mechanical valve. Dr E. Bos: Could I ask Dr. Oury from Missoula to make some comments? Dr J. H. Oury (Missoula, Montana, USA): First I would like to congratulate Dr. Rubay s group on the excellent results that we have heard today. That is entirely in keeping with the reputation of your group. I think these are important data as we begin to analyze critically this unique operation. I would like to tell you just very briefly about the Ross Registry and to bring you up to date on those results, to make one plea, and then to ask you a question. In terms of the registry, it was formed three years ago. It is in Montana, USA. However, I assure everyone that Montana has good connections with the outside world via fax and modem and telephone, and we have a tenacious Ross Registry coordinator, Ms. Katie Mackey, who is very helpful in tracking down these cases. In the past three years we have attempted to put together in the registry cases going back to Mr. Ross first operation in To date, we have collected 1500 cases, and a brief review of these cases, I think, is very informative in terms of the results we can expect. The overall mortality in this series is 2.3%. That has to do with what we call the classic era, pre 1986, which deals with Mr. Ross s data exclusively, and then since 1986, represents an exponential growth in the Ross procedure worldwide. Of interest, of the groups reporting since 1986, over 60% are reporting with 15 cases or less, so the argument that only the best series are being reported does not hold; on the contrary, if 60% of these cases are from groups who have done less than 15 cases, the overall mortality, therefore, includes the learning curve at their institutions. So, the overall operative mortality figures, I think, are fairly accurate. Number two, in terms of followup since 1986, the incidence of late failure now numbers a total of 16 patients with primary valve failure, that is, an incidence of approximately 1%. Obviously, as we continue to track these cases in the registry, this will become more and more significant. But I think that is somewhat reassuring to those of us doing the operation. Secondly, over 80% of the cases done in the modern era are the so-called root replacement, whereas in the classic era, the ratio was almost the opposite in terms of subcoronary versus root replacement. So I think all of that gives us some confidence in the path that all of us who are doing the Ross procedure are pursuing. My question to you, Dr. Rubay, is the method of stabilization of the aortic root. Obviously in children we look for growth, which is one of the major components of the Ross procedure, one of the major advantages. We look for growth, and yet one of the concerns as we look at registry data is the incidence of aortic insufficiency as we follow up these patients. That incidence has been very low, but it is certainly our hope that this valve is a permanent solution for aortic root pathology, and the technical details of exactly how we do the root, how we place the root I think are important. You have alluded to what you do in the very young infants and what you do in the young adults, that is, running versus interrupted. Do you have any other method for actually stabilizing the aortic root, number one. Secondly, I would simply make the plea that any of the surgeons doing the Ross procedure or embarking on the Ross procedure, please include these as part of the registry. It is the only way that we will really arrive at meaningful data as we continue to track this operation. Thank you. Dr J. E. Rubay: To answer your second question, it is quite difficult in small infants to reinforce the annulus level. What we do is to use continuous running sutures, in three parts, starting each at the lower level of the sinuses, and we reinforce by a second layer of continuous sutures. When they are older, we reinforce the annulus with a piece of pericardium. Regarding the registry, to my knowledge, all those patients are in your registry. Dr G. Petterson (Copenhagen, Denmark): Excellent results. I would like to ask you a question about the importance of a perfect haemodynamic result to the remodelling of the left ventricle and to achieve normal heart function. In children we often have to make compromises. Which compromises are acceptable and when should we proceed to a Ross operation with the potential of getting a really perfect result? Dr J. E. Rubay: I m not sure if I understand your question. Dr G. Petterson: Do you have any information about what degree remaining stenosis or insufficiency in patients with aortic valve disease that will still allow normalization of ventricular function? What is an acceptable compromise? Dr J. E. Rubay: In aortic insufficiency, a normal contractility index as measured by echocardiography is a good predicting factor of recovery. Dr D. N. Ross (London, UK): I would like to congratulate Dr. Rubay on his excellent results and very scientifically executed studies. I would re-emphasize the importance of the siting of the autograft root in an intra-annular position, and would like to know whether you ensure that the lower suture line is in an intra-annular position. The temptation, of course, is to transect the aorta above the annulus, and sew the root to the edge where it is unsupported by the muscle of the left ventricle. This, I think, accounts for a number of late dilatations. In addition we use a strip of pericardium in the lower suture line. Dr J. E. Rubay: Thank you very much, Mr. Ross. As we learned from you, we effectively insert the valve inside the annulus at a horizontal level crossing the anterior mitral leaflets and crossing the

8 J.E. Rubay et al. / European Journal of Cardio-thoracic Surgery 11 (1997) membranous septum if the annulus is large enough, otherwise we have sometimes to perform a modified Konno operation, of course. Dr E. Bos: Could you tell us what you do about the distal pulmonary artery anatomosis? Do you do it with one running suture or interrupted sutures? Dr J. E. Rubay: We use three continuous separate running suture. Dr E. Bos: You had two patients with pulmonary artery stenosis? Dr J. E. Rubay: Yes, with moderate gradients. Dr E. Bos: Were they on the distal anastomosis. Dr J. E. Rubay: Yes, on the distal part. Dr E. Bos: Even with three interrupted sutures? Dr J. E. Rubay: Yes. Dr E. Bos: Okay. Mr. Ross, I don t know if that solves the problem. Dr D. N. Ross: I think it is important to avoid that stenosis and it is very easy to purse-string the distal suture line. Incidentally after the anastomosis I check the right and left pulmonary arteries usually by passing my index finger through. Dr E. Bos: Yes, but he uses three interrupted sutures and still has this problem..