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Eur J Cardiothorac Surg 2004;25:925-930
© 2004 Elsevier Science NL

Midterm results of the Ross procedure

Department of Congenital Heart Disease, Guy's Hospital, Guy's and St Thomas Hospitals NHS Trust, St Thomas' Street, London SE1 9RT, UK

Received 17 October 2003; received in revised form 12 January 2004; accepted 23 January 2004.

^* Corresponding author. Flat 47, Royal Park Towers, 171 Flemington Road, North Melbourne, Vic. 3051, Australia. Tel.: +61-3-9329-9742; fax: +61-3-9345-6386
e-mail: nelson.a{at}bigfoot.com

	Abstract

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 
Objective: The lack of durable bioprosthetic valves and the inherent risks associated with anticoagulation for mechanical valves have led to the continued use of the Ross procedure, particularly in the pediatric population. Methods: We have reviewed our mid-term results retrospectively, following the Ross operation in both pediatric and adult groups. Results: Over a 11-year period from August 1991 to August 2002, 60 patients underwent the Ross procedure. The median age was 15 years (6–804 months), of which 63% were males and 55% were under the age of 20 years. The main indications were: aortic stenosis in 47 patients; aortic insufficiency in 6 patients; and mixed aortic valve disease in 28 patients. Fifteen patients had previously undergone balloon dilatation of the aortic valve, 4 had open valvotomy and 3 had both valvuloplasty procedures. The pulmonary autograft was implanted as a sub-coronary implant until 1995 (30%) after which time it was implanted using a partial inclusion cylinder technique (70%). There have been no deaths reported in this series. Over a median follow-up period of 59 months (2–122 months), there have been four re-operations for repair of autograft leak, and 2 adult patients have had autograft replacements. Conclusions: Despite the increased technical complexity, the Ross procedure can be performed safely in both paediatric and adult populations with satisfactory medium term results.

Key Words: Aortic valve disease • Ross procedure • Pulmonary autograft • Homograft

	1. Introduction

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 
Aortic valve replacement continues to present both a philosophical and technical challenge especially in children and young adults. Mechanical valves have proven durability but require life-long anticoagulation with its attendant risks of 0.3–7.4 events/100 patients/year of which 14.1–18.7% will be fatal [1]. Other difficulties include: variable compliance and alcohol consumption in the young adult; female patients who later wish to become pregnant; and the restriction of sporting activities. Biological valves have been shown to have an accelerated degeneration in the young [2]. Moreover, both mechanical and biological valves often require a second or third operation to address the need for a larger prosthesis in a growing child and neither valve provides a long lasting solution to complex left ventricular outflow tract obstruction (LVOTO).

Donald Ross first introduced aortic valve replacement with a pulmonary autograft in 1967 [3]. The increased technical difficulty of this procedure and concerns about early and late failure initially led to its limited usage. However, with added experience the advantages of the Ross procedure have become more fully appreciated. These include: absence of anticoagulation; appropriate sizing; cellular viability with growth potential proportional to somatic growth; excellent hemodynamic performance; and acceptable long-term durability [4].

Many now consider it to be the aortic valve replacement of choice in children and young especially female adults. Its indications have even been extended to infants and neonates and to the management of complex LVOTO in all age groups [5,6].

The purpose of this study was to review our experience with the Ross procedure.

	2. Methods

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 
2.1. Patient population
Sixty patients underwent the Ross operation at Guy's Hospital over a 11-year period between August 1991 and August 2002. The number of operations performed annually has remained fairly constant over this time period as shown below (Table 1).

There were 38 males (63%) and 22 females (37%). The median age was 15 years (6–804 months). Fifty-five percent (33) patients were younger than 20 years and 28% (17) patients were younger than 10 years. There were 5 infants in our series. The predominant lesion was aortic stenosis in 47 patients (78%) and aortic insufficiency (AI) in 6 patients (10%): 40 patients (67%) were noted to have a bicuspid aortic valve; 2 patients had a past history of rheumatic fever; 24 patients had previously undergone a total of 27 interventions (Table 2).

2.2. Surgical technique
Myocardial preservation was achieved by cold antegrade crystalloid cardioplegia. Sixteen (30%) autografts were implanted in a sub-coronary fashion and 37 (70%) were implanted as a partial inclusion cylinder. Since 1996 we have routinely employed the partial inclusion cylinder technique (except in babies less than 10 kg who have the autograft implanted using the root replacement technique).

The aorta is opened by a transverse incision just above the sino-tubular junction leaving about 20% of the circumference in continuity above the left coronary sinus. A vertical incision in the non-coronary sinus opens out the aortic root to allow easy access. The diseased aortic valve is excised back to healthy tissue. The autograft muscle is sutured to the left ventricular outflow at the level of the base of the aortic sinus. Vertical slits are cut in the pulmonary sinuses and the coronary ostia are anastomosed to the autograft. The autograft is then anastomosed to the distal aorta leaving the proximal edge of the aortotomy free. The vertical incision in the non-coronary sinus is loosely closed with interrupted sutures, so that the native aortic root will provide external support for the pulmonary sinuses. This technique cannot be applied to small babies (<10 kg). Instead they must have a free-standing root replacement technique.

We do not use any reinforcing material in either suture line in any age group. The right ventricular outflow tract (RVOT) is replaced with a fresh antibiotic-sterilised pulmonary homograft. The segment of the posterior circumference between the left main coronary artery and the cut-edge of the RVOT is sutured to the homograft with a row of interrupted vertical mattress sutures (Fig. 1) . We believe these to be more hemostatic at the outset thereby reducing the need to insert further sutures to control bleeding from this segment of the anastomosis at the end of the operation. Then these often need to be inserted in a sub-optimal visual field and can endanger the first septal perforator. The remaining suture lines are secured with a continuous prolene suture.

View larger version (36K): [in this window] [in a new window]   Fig. 1. Insertion of interrupted hemostatic sutures between the posterior segment of the proximal pulmonary homograft and the circumference of the RVOT between the lateral edge and the left main coronary artery.

2.4. Statistical analysis
Survival analysis and actuarial freedom from re-operation data was obtained using Kaplan–Meier methods.

	3. Results

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 
3.1. Operative data
Our median cross-clamp time was 74 min (55–138 min). Three patients (5.3%) required a re-sternotomy for bleeding. No patient was demonstrated to have more than mild regurgitation of the autograft or LVOTO on the immediate post-operative TTE. The median length of stay in the intensive care was 1 day (1–25 days). The median time to discharge was 10 days (5–77 days).

3.2. Hospital mortality
There have been no operative or early deaths in our series.

3.3. Morbidity
One patient developed complete heart block and required implantation of a permanent pacemaker before discharge. One patient could not be weaned from cardiopulmonary bypass and required extracorporeal membrane oxygenation for 3 days. He recovered successfully. One patient had generalised seizures postoperatively. He was discharged without any neurological sequelae and remains well 18 months later. Three patients had transient renal failure in their early post-operative period. All recovered fully with conservative management.

3.4. Midterm survival
There have been no deaths over a median follow-up of 69 months (11–132 months).

3.5. Reoperation
Five patients (8%) have had six re-operations.

3.6. Autograft failure
Three patients had autograft failure at a mean of 17.5 months after operation. A 63-year-old man (sub-coronary implant) had a repair of a ‘paravalvar’ leak under the left coronary ostium 2 months after his Ross operation. At re-operation, sutures were found to have ‘cut through’ the autograft annulus resulting in a dehiscence at the annulus. The sutures were re-inserted. Unfortunately, the same problem recurred 8 months later and the autograft was replaced with a bio-prosthesis. A 23-year-old man (sub-coronary implant) had a re-operation 5 months after surgery to repair a small tear of the right coronary cusp near the commissure. The tear was repaired primarily at re-operation and the patient remains free from autograft regurgitation at 104 months. Both the above re-operations were likely a combination of primary failure of the autograft and technical errors at the time of operation.

A 67-year-old female patient (partial inclusion cylinder) had a dilated annulus plicated with sub-commissural sutures 28 months after surgery. Her indication for autograft implantation was aortic regurgitation and we think that mismatch at the time of operation may have been responsible for her autograft regurgitation. She remains well 34 months later with no autograft regurgitation.

3.7. Endocarditis
Two patients have required re-operation for endocarditis. A 14-year-old boy presented with endocarditis of the pulmonary homograft and right lower lobe infarction. He underwent a replacement of his homograft with another fresh antibiotic-sterilised pulmonary homograft and a right lower lobectomy. The second patient was a 45-year-old man who presented with undiagnosed endocarditis affecting his pulmonary homograft. Four months later, he developed endocarditis of his autograft, which was replaced with a mechanical prosthesis. Both patients remain free of infection 67 and 29 months later respectively. There was no primary autograft endocarditis in our series.

Our overall freedom from re-operation is 84% and the freedom from re-operation in the subgroup of patients younger than 20 years is 97% (Fig. 2) .

View larger version (17K): [in this window] [in a new window]   Fig. 2. Kaplan–Meier curve showing freedom from re-operation in all patients compared to patients under the age of 20 years.

3.9. Homograft function
Eight patients had mild homograft regurgitation at follow-up. One patient (a 16-year-old boy) has moderate regurgitation and one (a 44-year-old female) has severe regurgitation. They are in Class 1–2 NYHA with good bi-ventricular function and normal bi-ventricular dimensions. No intervention is planned for these two patients at present but they will be followed up at six monthly intervals. As both these patients had no homograft regurgitation at discharge, their present condition likely represents primary homograft failure. We have had no significant homograft stenosis in our series.

3.10. Functional status
Five patients (10%) were in class 2 NYHA and all the remaining patients (90%) were in class 1 NYHA at their last follow-up.

	4. Discussion

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 
The pulmonary autograft is considered by many to be the best available substitute for the diseased aortic valve in children and young adults. This is especially true in the female patient who may later wish to become pregnant, since anticoagulation is not required. Elkins has suggested that the Ross operation is suitable for all patients with aortic valve disease and a life expectancy of more than 20 years [7]. Its use has been extended to neonates, infants and patients with complex left ventricular outflow obstruction [5,6]. Eleven patients were younger than 5 years in our series with 5 less than 1 year. Nine patients were older than 40 years. Some authors have reported an increased risk of failure in older age groups (>45 years) [8,9]. We believe the Ross is the best substitute for the aortic valve in patients with a life expectancy more than 20 years and in whom anticoagulation is not desired or contraindicated.

We have had no mortality in our series. With increasing experience other authors have reported similar results [6,11–14]. The overall mortality after 1987 reported in the International Registry of the Ross Procedure remains low at 2.5%. Overall mortality including Ross's pre-1987 patients is 3.1% [12].

Over a median follow-up of 69 months we have had no late deaths. Our mid-term results are similar to other reported series [13–14]. Late mortality reported in the International Registry of the Ross Procedure remains low at 1.7% [12]. Chambers et al. reported the long-term results of Ross' pioneer series of 131 hospital survivors operated at the National Heart Hospital, London from 1967 to 1984 [15]. Freedom from autograft replacement was 88 and 75% at 10 and 20 years respectively and freedom from replacement of the pulmonary position homografts was 89 and 80% respectively. Elkins reported 94% freedom from re-operation of the autograft at 8 years, 90% freedom from re-operation of the homograft 8 years [8]. Freedom from autograft re-operation or dysfunction (3+ insufficiency) was 83% at 9 years [8].

Failure of the autograft has been attributed to technical factors at the time of operation, endocarditis and progressive dilatation resulting in autograft regurgitation [15–17].

For a successful translocation of a competent pulmonary valve with adequate leaflet coaptation, the autograft must be implanted with as little distortion of the pulmonary valve geometry as possible to minimise regurgitation. Techniques of intra-aortic implantation of the autograft (sub-coronary and inclusion cylinder) are more complex and consequently perfect alignment of the cusps to prevent insufficiency is more difficult. Stelzer et al. introduced the free-standing root technique in 1989 [18]. It preserves root anatomy and allows the surgeon to use the pulmonary root as a functional unit thereby lessening the technical demands of the operation. This has led to an increased use of this technique even though it has a greater operative risk [16]. In early reports there appeared to be no difference between the two techniques [7,19]. However in a subsequent review of 195 operative survivors Elkins demonstrated a lower risk of more than 2+ aortic insufficiency and re-operation for in patients with a root replacement [4]. These results were confirmed in a recent analysis at 12 years [8]. The incidence of autograft valve insufficiency (3+) or re-operation was decreased by the root replacement technique (88% versus 77% at 8 years). These findings were also supported by the long-term results of the pioneer series where re-operation for autograft regurgitation was less frequent amongst root autografts (2 out of 20) as compared to valve autografts (27 out of 107) [15]. As in the earlier reports [4,8] the principal dysfunction of regurgitation appeared primarily technical in nature probably from mal-suspension of the autografts cusps at implantation.

One concern of the root technique is progressive late dilatation of the pulmonary root following exposure to systemic pressure. Dilatation of the aortic annulus or the sino-tubular junction causes AI [22]. Dilatation of the sinuses without dilatation of the annulus or the sino-tubular junction does not cause AI though dimensions >55 mm would fit most surgeons' criterion for surgical repair. David et al. have suggested adjusting the diameters of both the aortic annulus and the sino-tubular junction at the time of operation [21]. Elkins found enlargement of the annulus and the sinuses in both root replacement and intra-aortic implants [7,23]. The enlargement was proportional to the somatic growth of the child and was not associated with autograft regurgitation. However, the diameters at the sinus of the root replacements were larger than the 50% confidence limits for the diameters in the normal population. In both reports the increased sinus diameter did not co-relate to an increase in autograft insufficiency [7,8,19].

In a later report Schmidtke et al. also observed a significantly increased diameter of the sinuses in free-standing root compared with the intra-aortic implants at 70 months suggesting that the intra-aortic methods of implantation have a dilatation protecting effect. David et al. reported similar findings [21]. They demonstrated that the inclusion cylinder technique prevents or at least retards dilatation of the sinuses of Valsalva and the ST junction. Resolution of this debate will require longer follow-up.

We have implanted the autograft in a sub-coronary fashion until 1995 (16 patients: 30%) and as a partial intra-aortic inclusion cylinder thereafter (37 patients: 70%). Of the 3 failures, 2 occurred in the sub-coronary group and are likely to arise from a combination of primary failure and technical errors. The only patient found to have annular dilatation causing significant regurgitation 28 months post-operatively had an inclusion cylinder intra-aortic implant. This was likely to have resulted from technical mismatch at the time of implantation. We have chosen to translocate the autograft using the partial inclusion cylinder technique because we believe that it retards the subsequent dilatation of the autograft and hence preserves the geometry of the autograft valve sinuses.

Patients with a pre-operative diagnosis of aortic insufficiency have been demonstrated to have an increased risk of annular dilatation with central autograft insufficiency resulting in higher rates of re-operation [10,16]. In a recently reported series of 195 patients, 16 patients all with AI or mixed aortic valve disease were found to have an aortic annulus with >4 mm discrepancy. The author recommends an annulus reduction and fixation of annulus size at the time of the Ross procedure [4,8]. The use of prosthetic material may however interfere with growth in children and an alternative method of aortic root tailoring had been described by Bove and associates [11].

Gerosa et al. reported an incidence of bacterial endocarditis of 1.2% per patient per year [17]. Chambers et al. and Stelzer et al. have also reported an incidence of 12/131 (9%) and 11/145 (7%), respectively [15,18]. This is in contrast to other series where the pulmonary autograft has been used successfully in the management of aortic endocarditis [4,8,19,20,22]. We have had three definite episode of endocarditis in 2 patients (3%) and in both these patients the pulmonary homograft was the initial valve to be affected. There have been no isolated cases of autograft endocarditis. The aortic homograft remains our valve of choice in the management of aortic endocarditis.

The advantages of the autograft outweigh concerns regarding the creation of potential pulmonary valve disease. Potential problems include questions regarding durability, absence of growth in children and the need for re-operation. Most surgeons choose to replace the pulmonary valve with a pulmonary homograft [4,15]. Pulmonary homografts fare better in the pulmonary position when compared to aortic homografts [4]. The freedom from re-operation of the pulmonary position homograft in Ross' pioneer series was 89 and 88% at 10 and 20 years, respectively [15]. Other authors have reported similarly excellent durability albeit over a shorter follow-up [23]. Cryopreserved homografts may have a better long-term performance than fresh antibiotic homografts [15]. The presence of viable cells may however be responsible for an immune response resulting in early rapid stenosis [4,15,23]. We use antibiotic sterilised homografts in our institute because they are more reliably available and have comparable longer-term performance. We have not seen any case of accelerated degeneration during follow-up.

Young children can be expected to outgrow their homograft. Re-operation to replace the pulmonary homograft is a relatively uncomplicated procedure and can be accomplished with low mortality as shown with the experience gained during the treatment of other congenital defects [24]. Trans-catheter intervention can often prolong the life of a homograft. This would permit the surgeon to implant a larger conduit in an older patient at the time of conduit change. By increasing the intervals between re-operations, the number of repeat procedures can be minimised.

In conclusion, the long-term results of a few and the mid-term results of a growing number of surgeons support the use of the Ross procedure as an excellent alternative in the management of aortic valve disease, especially in children and young adults.

	Footnotes

 
Presented at 2002 Annual Scientific Meeting of the Society of Cardiothoracic Surgeons of Great Britain and Ireland, Bournemouth, UK, March 2002.

	References

Top Abstract 1. Introduction 2. Methods 3. Results 4. Discussion References

 

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2. David T.E. Bioprosthetic valves. Heart Surg Forum 2003;6:107-108.
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16. Elkins R.C., Knott-Craig C.J., Howell C.E. Pulmonary autografts in patients with aortic annulus dysplasia. Ann Thorac Surg 1996;61:1141-1145.[Abstract/Free Full Text]
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21. David T.E., Omran A., Ivanov J., Armstrong S., de Sa M.P., Sonnenberg B., Webb G. Dilation of the pulmonary autograft after the Ross procedure. J Thorac Cardiovasc Surg 2000;119:210-220.[Abstract/Free Full Text]
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24. Discigil B., Dearani J.A., Puga F.J., Schaff H.V., Hagler D.J., Warnes C.A., Danielson G.K. Late pulmonary valve replacement after repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 2001;121:344-351.

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Alphonso, N. Articles by Anderson, D. Search for Related Content PubMed PubMed Citation Articles by Alphonso, N. Articles by Anderson, D. Related Collections Cardiac - other Valve disease