HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

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 Author home page(s): Jan T. Christenson Jorge Sierra Jalal Jolou Afksendiyos Kalangos Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Christenson, J. T. Articles by Kalangos, A. Search for Related Content PubMed PubMed Citation Articles by Christenson, J. T. Articles by Kalangos, A. Related Collections Congenital - cyanotic Related Article

---

Original Articles: Pediatric Cardiac

Homografts and Xenografts for Right Ventricular Outflow Tract Reconstruction: Long-Term Results

^a Division of Cardiovascular Surgery, University Hospital of Geneva, Faculty of Medicine, University of Geneva, Geneva, Switzerland
^b Department of Pediatric Cardiology, University Hospital of Geneva, Faculty of Medicine, University of Geneva, Geneva, Switzerland

Accepted for publication June 11, 2010.

^_* Address correspondence to Dr Christenson, Division of Cardiovascular Surgery, University Hospital of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH 1211, Switzerland (Email: jan.christenson{at}hcuge.ch).

	Abstract

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
Background: Cryopreserved valved homografts are the most commonly used conduit for right ventricular outflow tract reconstruction in children. Early need for reoperation owing to accelerated fibrocalcification has been observed in neonates and children younger than 3 years. A valved bovine jugular vein conduit, Contegra, has shown good early results, without early accelerated fibrocalcification even in the very young patients. This study determined long-term results of homografts and midterm results of Contegra grafts, with special emphasis on reoperation rate.

Methods: Between January 1993 and March 2009, 205 children received cryopreserved aortic homografts (n = 120, 66 blood group compatible [iso] and 54 non–blood group compatible [non-iso]) or Contegra grafts (n = 85, introduced in January 2000) for right ventricular outflow tract reconstruction and were followed from 6 months to 16 years. Primary diagnosis was tetralogy of Fallot (47%), pulmonary stenosis and atresia (19%), and truncus arteriosus (11%). Conduit dysfunction and need for reoperation were evaluated during follow-up.

Results: There were no hospital deaths in the homograft group and 2 deaths of conduit-unrelated cause in the Contegra group, During follow-up 3 patients died in the homograft group from graft-unrelated cause, and none died in the Contegra group. Early reoperation as a result of fibrocalcification and stenosis (within 2 years) was required in 1 Contegra graft patient (1.1%) compared with 8 patients in the homograft group (6.7%), all non-iso. Freedom from reoperation for Contegra grafts was 89.0% at 9 years, compared with non-iso homografts 63.0% and iso-homografts 85.7%.

Conclusions: Non–blood group–compatible homografts have a significantly higher early reoperation rate than blood group–compatible homografts. Contegra grafts have a very low early reoperation rate and could therefore be used in neonates and children younger than 3 years of age, if a blood group–compatible homograft cannot be found. In children older than 3 years blood group compatibility is less important.

	Introduction

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
Cryopreserved valved homografts have been used successfully since the 1960s for reconstruction of the right ventricular outflow tract (RVOT) in children [1–3]. Early results of this conduit have been good, but as younger patients have undergone RVOT reconstruction, an accelerated fibrocalcification in aortic homografts placed in the pulmonary position has been observed, with a resulting need for early reoperation [4–6]. In a recent study Christenson and coworkers [7] have shown that ABO blood incompatibility between donor and receiver may play an important role in the development of accelerated fibrocalcification of the graft, particularly when the homograft receiver is 3 years old or younger. However, if ABO blood group compatibility between donor and receiver is observed, less fibrocalcification occurs and need for early reoperation is dramatically diminished [7]. The explanation for these findings could be that cryopreservation may provide viable endothelial cells and perhaps also viable fibroblasts, thus contributing to a greater proportion of antigenically active cells that could result in a more intense host response, particularly in the very young patient [8, 9].

Difficulties in obtaining cryopreserved valved homografts with suitable sizes for very young patients and at the same time observing ABO blood group compatibility between donor and receiver are an obvious obstacle. Therefore a xenograft, the Contegra graft (Medtronic Inc, Minneapolis, MN) has been developed. This graft is a heterologous bovine jugular vein graft containing a trileaflet venous valve, which is preserved in a buffered 0.6% glutaraldehyde solution under zero pressure conditions, which preserves the flexibility of the leaflets. In addition this graft is available in a wide range of sizes, from 12 to 22 mm. Clinical reports with short-term to midterm follow-up have described excellent results and a low calcification rate [10–14]. However, supravalvar stenosis and graft dilatation have been reported [15, 16].

In the present report we have compared midterm outcomes for cryopreserved aortic homografts (ABO blood group compatible and incompatible) and Contegra grafts used for RVOT reconstruction in a pediatric population, with special emphasis on early reoperation rates.

	Patients and Methods

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
The institutional review board approved this follow-up study and waived the requirement for patient consent and authorization (CER-08-043R).

Cryopreserved Homografts
From June 1993 to March 2009, 120 pediatric patients (63 boys and 57 girls) had cryopreserved aortic homografts implanted for RVOT reconstruction. The primary diagnosis of their congenital lesions is listed in Table 1.The homografts were obtained from two sources, the European Homograft Bank (Brussels Military Hospital, Belgium) and CryoLife Inc (Marietta, GA). Thirty-one homografts came from CryoLife and 89 homografts were from the European Homograft Bank, with an equal distribution of iso (ABO blood group compatibility between donor and receiver) and non-iso (ABO blood group incompatible between donor and receiver) graft from both sources. The technique for preparation of antibiotic-sterilized cryopreserved homografts and storage in liquid nitrogen has been described earlier [17]. The mean age of the patients was 6.4 ± 4.4 years, ranging from 1 month to 17 years of age. Forty-four patients (37%) were 3 years old or younger at the time of surgery. Fifty-seven patients (48%) had undergone at least one earlier intervention (Table 2). Sixty-six patients (55%) had the same ABO blood group as the donor or potentially compatible, but not identical, homografts (iso group), whereas in 54 patients (45%) there was ABO blood group incompatibility (non-iso group).

Surgical Technique
The surgical technique has been described earlier in detail [7, 14]. Two surgeons performed all operations. All operations were performed through median sternotomy, and in most cases standard cardiopulmonary bypass techniques in moderate hypothermia (28 to 32°C) were used. Conduit size was determined and compared with normal pulmonary valve size for body surface area (z score) at the time of insertion. Oversizing was defined as a z score of 2.0 or greater. The mean z score was 2.2 in this series. The diameter of the homografts in this series ranged from 14 to 24 mm (mean diameter, 19 mm). The mean diameter of the Contegra conduit was 14 mm, ranging from 12 to 18 mm. The RVOT conduit was inserted between an extended pulmonary bifurcation and the right ventricle (RV) at the level of the crista supraventricularis. The distal anastomoses were performed first. In some patients, without group differences, bovine glutaraldehyde-treated pericardium was used to enlarge the pulmonary arteries or to provide continuity between the pulmonary arteries. The proximal anastomosis was made to a vertical infundibulotomy. In addition a patch of bovine or autologous pericardium was inserted as a hood to cover the enlarged infundibulotomy. No prosthetic material was used. Associated surgical procedures are listed in Table 3. There were no significant differences among the groups.

Statistical Analysis
Data are presented as mean ± standard deviation. Continuous variables were analyzed with Student's t test and categorical variables using the ² test. Actuarial estimates were calculated using the Kaplan-Meier method. Group differences at 9 years were analyzed by log-rank tests. A probability value of less than 0.05 was considered statistically significant.

	Results

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
Mortality
There was no hospital mortality in the homograft group, whereas 2 patients died of graft-unrelated causes in the Contegra graft group (second and eighth postoperative days). The deaths were attributed to complications of pulmonary hypertension. One patient had as an additional procedure a banding of neo-pulmonary artery that necessitated a debanding on the second postoperative day, after which procedure the patient succumbed. The second mortality was attributable to RV failure on the eighth postoperative day. Primary diagnosis, sex distribution, previous surgical interventions, and associated surgical procedures at the time of RVOT reconstruction with graft did not reveal any statistically significant differences among the groups. Mean age was lower in the Contegra graft group, and there were more patients 3 years of age and younger in the Contegra group compared with the two homograft groups, a statistically insignificant difference. The mean gradient from the RV to the pulmonary artery was 12.6 ± 9.8 mm Hg, ranging from 0 to 49 mm Hg, at 3 months after homograft implantation, and 14.2 ± 9.5 mm Hg, ranging from 0 to 50 mm Hg in the Contegra group, a statistically insignificant difference. During follow-up 3 patients died in the homograft group of RVOT-unrelated causes (cancer, pneumonia, and accident).

Follow-Up
The follow-up was complete with 83 Contegras, 65 iso homografts, and 52 non-iso homografts available for follow up. During follow-up 6 patients required reoperation in the Contegra group (7.1%) compared with 31 patients in the homograft group. Reasons for reoperation in the Contegra group included a severe stenosis of the distal anastomosis in 1 patient on day 1 postoperatively requiring refashioning of the distal anastomosis. One patient had a strong retraction of the graft leaflet requiring graft replacement on the 28th postoperative day. One patient had a peri-Contegra graft abscess that healed after drainage and antibiotic therapy 131 days after surgery. Contegra graft dilatation in 1 patient 2 years after implantation and graft stenosis in 3 patients required replacement of the Contegra graft using cryopreserved homografts 1, 2, and 6 years after the initial graft implantation. One patient experienced graft endocarditis 3 months after implantation, which required graft replacement.

In the homograft group 31 reoperations were required during the follow-up because of graft calcification or valvar dysfunction in all patients, requiring graft replacement. There were no statistically significant differences in reoperation rate between the iso homograft group and the Contegra group. However, the overall reoperation rate was higher when non-ABO compatible homografts were used, 21 of 54 (38.9%), compared with when ABO-compatible homografts were used, 10 of 66 (15.4%; p = 0.0023; Table 4). There were significantly fewer early reoperations during the first and second year after graft implantation when ABO-compatible homografts were used, 0 of 66 (0.0%), compared with when non-ABO-compatible homografts were used, 8 of 54 (14.8%; p = 0.001).

View larger version (23K): [in this window] [in a new window]   Fig 1. Overall actuarial freedom from reoperation in 205 pediatric patients undergoing right ventricular outflow tract reconstruction with Contegra grafts (n = 85) and cryopreserved valved homografts (HG: n = 120), the latter separated into ABO blood group compatible (Iso: n = 66) and ABO blood group-incompatible (Non Iso: n = 54) grafts.

All children 3 years old or younger who exhibited homograft fibrocalcification and required a graft replacement in the early postoperative period, within 2 years of the initial implantation had ABO blood group incompatibility between homograft donor and recipient (non-iso group; 50%, 8 of 16 patients). No early fibrocalcification was observed in the young when blood group compatibility was observed (iso group; 0 of 28; p = 0.0001). This significant difference between the iso group and the non-iso group was not observed in patients older than 5 years at the initial graft implantation (Table 4). There was no difference in outcomes when comparing grafts from the two homograft sources.

Impact of Small Size Right Ventricular Outflow Tract Conduit at Initial Operation and Early Reoperation Rate
A total of 20 cryopreserved homografts in this series were 16 mm or smaller (20 of 120, 16.7%), whereas in the Contegra group 78 of 85 grafts (91.8%) were size 16 mm or less. In the Contegra group 4 patients receiving small conduits, 12 to 16 mm, required reoperation for structural deterioration of the graft (4 of 78, 5.1%), which was a significantly lower reoperation rate than observed for homografts 16 mm or less, 11 of 20 (55.0%; p < 0.001). Moreover 8 of these 11 (72.7%) reoperations were necessary within the first 2 years after graft implantation, all being non-ABO-compatible cryopreserved homografts. Necessity for reoperations within the first 2 years was significantly lower for Contegra grafts than for non-iso cryopreserved homografts, 2 of 78 (2.6%) and 8 of 20 (40.0%), respectively (p < 0.001).

A total of 37 patients underwent reoperation with RVOT graft replacement during the study period (31 initial homografts and 6 Contegra grafts), 1 month to 15 years after the initial operation. Indications for reoperation were (1) progressive RV dilatation with more than grade II pulmonary regurgitation with or without stenosis of any degree, (2) RV end-systolic volume (indexed) of 150 mL/cm² or greater, and (3) stenosis of the homograft exceeding a peak systolic gradient of more than 50 mm Hg [18]. The mean age of patients at the time of the reoperation was 8.9 ± 5.3 years, ranging from 1 to 17 years of age. Right ventricular outflow tract graft replacement was performed using aortic cross-clamping and cardiopulmonary bypass in 22 of 37 patients (59.5%), and as a beating heart procedure with only cardiopulmonary bypass support in 15 of 37 patients (40.5%). Since January 2005 replacement of the RV outflow conduit has more frequently been done on beating heart with cardiopulmonary bypass support (10 of 17 patients, 59%), with no adverse effects. However, it is important to note that exclusion of any residual shunt is mandatory to avoid air embolism. In cases in which the distal anastomosis of the RVOT conduit was stenotic as well as in cases with right pulmonary branch stenosis, cross-clamping and section of the aorta was often necessary to be able to enlarge the right pulmonary artery or the stenotic bifurcation with extended incisions toward the two pulmonary branches.

	Comment

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
Cryopreserved homografts have been used as a conduit between the RV and the pulmonary arteries for reconstruction of the RVOT since the late 1960s [19]. A pulmonary homograft is the preferred conduit but is often quite difficult to obtain [20]. Aortic homografts have therefore been commonly used in the pulmonary position for RVOT reconstruction. Excellent patient survival after RVOT reconstruction using homografts has been reported [19, 21–22], which also was demonstrated in the present series. However, despite providing good hemodynamic results without the need for anticoagulation, homografts are not the ideal conduit because of their limited longevity and either stenotic lesions or incompetency with time. In children, the need for reintervention on dysfunctional conduits is primarily aimed at relieving conduit stenosis, because the consequences of regurgitation are usually well tolerated until young adulthood, as confirmed in our series [23]. When used in neonates and very young children, poor homograft longevity has been observed [24].

An accelerated aortic homograft fibrocalcification has been described to occur when homografts are used in very young patients [7]. It has been thought that cryopreservation provides viable endothelial cells and fibroblasts, which could participate in a more intense host response [25]. Christenson and associates [7] have recently demonstrated that ABO blood group incompatibility between homograft donor and recipient plays an important role in the development of accelerated fibrocalcification in homografts, particularly in patients younger than 3 years of age at the time of graft implantation. When blood group compatibility was respected, the need for early reintervention was significantly lower compared with instances in which blood group compatibility could not be respected. These findings are reconfirmed in the present extended series. Some series have not shown any relationship between ABO matching and conduit failure [26, 27]. However, in a recent article it was shown that AB antigen expression was found in cryopreserved homograft conduits, but not leaflets, which could theoretically support our findings regarding increased risk for conduit failure of non-iso conduits in young patients [28].

The limited supply of cryopreserved homografts, particularly in small sizes suitable for the pediatric population together with the request for blood group donor to receiver compatibility, has led to the search for alternative conduits. The Contegra valved bovine jugular vein graft has become an interesting alternative in RVOT reconstruction with excellent short-term to midterm results [12, 14, 21], confirmed by the present series. The Contegra graft is readily available in a broad spectrum of different sizes and could be an alternative to cryopreserved homografts, particularly in RVOT reconstructions in neonates and very young children, when blood group–compatible homografts in adequate size cannot be obtained.

Patient demographics, primary diagnosis, and surgical procedures were the same among the groups, with the only differences being that significantly more children 3 years of age and younger received Contegra grafts compared with the homograft group. This is a reflection of our initial experience with the Contegra graft, particularly in the very young, when the Contegra graft performed significantly better than blood group–incompatible aortic homografts, but inferior to blood group–compatible homografts. In these situations the Contegra graft has become our preferred conduit in children 3 years of age and younger. Anesthesia and cardiopulmonary bypass as well as surgical techniques were the same in all groups. We consistently used autologous or bovine pericardium when patches were needed as a hood to cover an enlarged ventriculotomy or for patch enlargement of pulmonary arteries. No synthetic material was used.

Another factor previously identified to predict homograft longevity include size of the conduit, either oversizing or undersizing of the conduit to greater than or less than average pulmonary valve size relative to body surface area (z score). It has been clearly demonstrated that freedom from a second conduit reoperation after a first conduit replacement was shorter in smaller children and undersized conduits [25]. However. oversizing has been advocated by many authors as an important issue [29, 30]. The practice of oversizing valves was observed in our series.

The need for reoperation was significantly higher in the non-iso homograft group compared with the Contegra group, but when ABO blood group compatibility was observed, early homograft reinterventions were less common than in the Contegra group (Fig 1). The majority of our patients had as a primary diagnosis tetralogy of Fallot, and only few with transposition of the great vessels, which could explain the good results in our series. This is also consistent with data reported by Dearani and associates, as well as others [2, 19]. The relatively high number of tetralogy of Fallot in this series is that we prefer using a conduit in cases of a small pulmonary annulus rather than a transannular patch to avoid the negative impact a pulmonary insufficiency might have on a noncompliant RV immediately after surgery [31].

Reasons for reintervention and conduit replacement were fibrocalcification and conduit stenosis in all patients in the homograft group. In the Contegra group, early reoperations were because of strong leaflet retraction in 1 patient, which could represent an aggressive immune-inflammatory reaction, and endocarditis in another patient. Later reoperations involved 3 grafts (3 of 85, 3.5%) that required conduit replacement owing to distal stenosis, and in 1 patient, graft dilatation (1 of 85, 1.2%) was the reason for replacement of the conduit. In this series the necessity for reoperations within the first 2 years of RVOT implantation demonstrated a significantly lower reoperation rate for Contegra grafts as well as for iso homografts when compared with non-iso cryopreserved homografts. Because crosslinked valved bovine jugular vein conduits are available in smaller sizes, the results of this study suggest they are a reasonable choice as an RVOT conduit when a blood group–compatible homograft of appropriate size cannot be obtained for patients younger than 3 years of age. One explanation for this could be that the Contegra graft may have a time window conferred by glutaraldehyde during which time xenogeneic proteins are not recognized as antigenic.

When reoperation becomes necessary the replacement of the RVOT conduit can often be performed on a beating heart with cardiopulmonary bypass support.

In conclusion, cryopreserved homografts are commonly used to establish RV to pulmonary artery continuity in the treatment of various congenital heart conditions. Offering excellent hemodynamics without necessity for anticoagulation therapy, the homograft is not the ideal conduit because of its limited availability and longevity.

Previous studies as well as data presented in this series have indicated that early aortic homograft failure is more in keeping with rejection than the inevitable tissue degeneration seen in later failures. To avoid this reaction, strict blood group compatibility between homograft receiver and donor should be observed.

The crosslinked valved bovine jugular vein conduit is available in small sizes and should therefore become the choice for an RVOT conduit when a blood group–compatible homograft of small size cannot be obtained, particularly in children 3 years old and younger. In older children the immunologic reaction with aortic homografts seems to fade away and have no impact on longevity of the conduit.

Excellent long-term results have been demonstrated when cryopreserved aortic homografts are used as RVOT conduits when blood group compatibility between recipient and donor is respected. The Contegra graft is clearly better than blood group–incompatible aortic homografts at midterm, and similar compared with a blood group–compatible aortic homograft when used in the very young. For children older than 5 years at the time of implant, ABO matching seems to be less important, with the same reoperation rate as that for biocompatible cryopreserved homografts.

	Acknowledgments

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 
Statistical support was provided by the Clinical Research Center, University of Geneva and Geneva University Hospitals (C. Combescure).

	References

Top Abstract Introduction Patients and Methods Results Comment Acknowledgments References

 

1. Ross DN, Somerville J. Correction of pulmonary atresia with homograft aortic valve Lancet 1966;2:521-527.[Medline]
2. Hawkins JA, Bailey WW, Dillon T, Schwartz DC. Midterm results with cryopreserved allograft valved conduits from right ventricle to the pulmonary arteries J Thorac Cardiovasc Surg 1992;104:910-916.[Abstract]
3. Niwaya K, Knott-Graig CJ, Lane MM, Chandrasekaren K, Overholt ED, Elkins RC. Cryopreserved homograft valves in the pulmonary position: risk analysis for intermediate-term failure J Thorac Cardiovasc Surg 1999;117:141-147.[Abstract/Free Full Text]
4. Chan KC, Fyfe DA, McKay CA, Sade RM, Crawford FA. Right ventricular outflow tract reconstruction with cryopreserved homografts in pediatric patients: intermediate-term follow-up with serial echocardiographic assessment J Am Coll Cardiol 1994;24:483-489.[Medline]
5. Clarke DR, Campbell DN, Hayward AR, Bishop DA. Degeneration of aortic valve allografts in young recipients J Thorac Cardiovasc Surg 1993;105:934-943.[Abstract]
6. Schorn K, Yankah AC, Alexi-Meskhishvilli VA, Weng Y, Lange PE, Hertzer R. Risk factors for early degeneration of allografts in pulmonary circulation Eur J Cardiothorac Surg 1997;11:62-69.[Abstract/Free Full Text]
7. Christenson JT, Vala D, Sierra J, Beghetti M, Kalangos A. Blood group incompatibility and accelerated homograft fibrocalcifications J Thorac Cardiovasc Surg 2004;127:242-250.[Abstract/Free Full Text]
8. Balch CM, Karp RB. Blood group compatibility and aortic valve allotransplantation in man J Thorac Cardiovasc Surg 1975;70:256-259.[Abstract]
9. Ranjani B, Mee RB, Ratcliff NB. Evidence of rejection of homograft cardiac valves in infants J Thorac Cardiovasc Surg 1998;115:111-117.[Abstract/Free Full Text]
10. Ichikawa Y, Noishiki Y, Yamamoto K, Kando J, Matsumoto A. Use of bovine jugular vein graft with natural valve for right ventricular outflow tract reconstruction: a one-year animal study J Thorac Cardiovasc Surg 1997;114:224-233.[Abstract/Free Full Text]
11. Bove T, Demanet H, Wauthy P, et al. Early results of valved bovine jugular vein conduit versus bicuspid homograft fro right ventricular outflow tract reconstruction Ann Thorac Surg 2002;74:536-541.[Abstract/Free Full Text]
12. Breymann T, Blanz U, Wojtalik MA, et al. European Contegra multicentre study: 7-yer results after 165 valved bovine jugular vein graft implantations Thorac Cardiovasc Surg 2009;57:257-269.[Medline]
13. Cono AF, Qanadi SD, Serkarski A, et al. Bovine valved xenografts in pulmonary position: medium-term follow-up with excellent hemodynamics and freedom from calcification Ann Thorac Surg 2004;78:1382-1388.[Abstract/Free Full Text]
14. Sierra J, Christenson JT, Lahlaidi NH, Beghetti M, Kalangos A. Right ventricular outflow tract reconstruction, what conduit to use?. Homograft or Contegra?. Ann Thorac Surg 2007;84:606-610.[Abstract/Free Full Text]
15. Meyns B, Van Garsse L, Boshoff D, et al. The Contegra conduit in right ventricular outflow tract induces supra valvar stenosis J Thorac Cardiovasc Surg 2004;128:834-840.[Abstract/Free Full Text]
16. Göber V, Berdat P, Pavlovic M, Pfammatter J-P, Carrel P. Adverse mid-term outcome following RVOT reconstruction using Contegra valved bovine jugular vein Ann Thorac Surg 2005;79:625-631.[Abstract/Free Full Text]
17. McNally R, Barwick R, Smith-Morse B, Rhodes P. Actuarial analysis of a uniform and reliable preservation method for viable heart valve allografts Ann Thorac Surg 1989;48:583-584.
18. Loukanov T, Sebening C, Springer W, et al. Replacement of valved right ventricular to pulmonary artery conduits: an observational study with focus on right ventricular geometry Clin Res Cardiol 2008;97:169-175.[Medline]
19. Dearani JA, Danielson GK, Puga FJ, et al. Late follow-up of 1095 patients undergoing operation for complex congenital heart disease utilizing right ventricle to pulmonary artery conduits Ann Thorac Surg 2003;75:399-411.[Abstract/Free Full Text]
20. Tweddell JS, Pelech AN, Frommelt PC, et al. Factors affecting longevity of homograft valves use in right ventricular outflow tract reconstruction for congenital disease Circulation 2000;102(Suppl 3):III-130-III-135.[Abstract/Free Full Text]
21. Brown JW, Ruzmetov M, Rodefeld, MD, Vijay P, Darragh RK. Valved bovine jugular vein conduits for right ventricular outflow tract reconstruction in children: an attractive alternative to pulmonary homograft Ann Thorac Surg 2006;82:909-916.[Abstract/Free Full Text]
22. Homann M, Haehnel JC, Mendler N, et al. Reconstruction of the RVOT with valved biological conduits: 25 years experience with allografts and xenografts Eur J Cardiothorac Surg 2000;17:624-630.[Abstract/Free Full Text]
23. Baskett RJ, Nanton MA, Warren AE, Ross DB. Human leucocyte antigen-DR and ABO mismatch are associated with accelerated homograft valve failure in children: implications of therapeutic interventions J Thorac Cardiovasc Surg 2003;126:232-239.[Abstract/Free Full Text]
24. Kaza AK, Lim H-G, Dibardino DJ, et al. Long-term results of right ventricular tract reconstruction in neonatal cardiac surgery: options and outcomes J Thorac Cardiovasc Surg 2009;138:911-916.[Abstract/Free Full Text]
25. Shaddy RE, Hawkins JA. Immunology and failure of valved homografts in children Ann Thorac Surg 2002;74:1271-1275.[Abstract/Free Full Text]
26. Jashari R, Daenen W, Meyns B, Vanderkelen A. Is ABO group incompatibility really the reason for accelerated failure of cryopreserved allografts in very young patients?. Echography assessment of the European Homograft Bank (EHB) cryopreserved allografts used for reconstruction of the right ventricular outflow tract. Cell Tissue Bank 2004;5:253-259.[Medline]
27. Lange R, Weipert J, Homann M, et al. Performance of allografts and xenografts for right ventricular outflow tract reconstruction Ann Thorac Surg 2001;71(Suppl):S365-S367.[Medline]
28. Zachariah JPV, Pigula FA, Mayer JE, McElhinney DB. Right ventricular to pulmonary artery conduit augmentation compared with replacement in young children Ann Thorac Surg 2009;88:574-580.[Abstract/Free Full Text]
29. Niemantsverdriet MB, Ottenkamp J, Gauvereau K, Del Nido PJ, Hazenkamp MG, Jenkins KJ. Determinants of right ventricular outflow tract conduit longevity: a multinational analysis Congenit Heart Dis 2008;3:176-184.[Medline]
30. Askovich B, Hawkins JA, Sower CT, et al. Right ventricle-to-pulmonary artery conduit longevity: is it related to allograft size? Ann Thorac Surg 2007;84:907-912.[Abstract/Free Full Text]
31. Warner KG, O'Brien PKH, Rhodes J, Kaur A, Robinson DA, Payne DD. Expanding the indications for pulmonary valve replacement after repair of tetralogy of Fallot Ann Thorac Surg 2003;76:1066-1072.[Abstract/Free Full Text]

This article has been cited by other articles:

				F. Vogt, B. M. Boll, A.-L. Boulesteix, E. Kilian, G. Santarpino, B. Reichart, and C. Schmitz Homografts in aortic position: does blood group incompatibility have an impact on patient outcomes? Interact CardioVasc Thorac Surg, May 1, 2013; 16(5): 619 - 624. [Abstract] [Full Text] [PDF]

				A. M. Sharkey and A. Sharma Tetralogy of Fallot: Anatomic Variants and Their Impact on Surgical Management Seminars in Cardiothoracic and Vascular Anesthesia, June 1, 2012; 16(2): 88 - 96. [Abstract] [PDF]

				M. M. Mokhles, A. J. van den Bogaerdt, J. J. M. Takkenberg, and A. J. J. C. Bogers Right Ventricular Outflow Tract Reconstruction: The Impact of Allograft Characteristics Ann. Thorac. Surg., June 1, 2011; 91(6): 2025 - 2025. [Full Text] [PDF]

				H. M. Burkhart Invited Commentary Ann. Thorac. Surg., October 1, 2010; 90(4): 1293 - 1294. [Full Text] [PDF]

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 Author home page(s): Jan T. Christenson Jorge Sierra Jalal Jolou Afksendiyos Kalangos Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Christenson, J. T. Articles by Kalangos, A. Search for Related Content PubMed PubMed Citation Articles by Christenson, J. T. Articles by Kalangos, A. Related Collections Congenital - cyanotic Related Article