ATS
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Christian Schreiber
Martin Kostolny
Julie Cleuziou
Klaus Holper
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schreiber, C.
Right arrow Articles by Lange, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schreiber, C.
Right arrow Articles by Lange, R.
Related Collections
Right arrow Congenital - cyanotic

Ann Thorac Surg 2006;82:179-185
© 2006 The Society of Thoracic Surgeons

Original article: Cardiovascular

Early Graft Failure of Small-Sized Porcine-Valved Conduits in Reconstruction of the Right Ventricular Outflow Tract

Christian Schreiber, MD, PhD a , b , c , * , Stefanie Sassen, MD a , b , c , Martin Kostolny, MD a , b , c , Jürgen Hörer, MD a , b , c , Julie Cleuziou, MD a , b , c , Michael Wottke, MD, MPH a , b , c , Klaus Holper, MD, PhD a , b , c , Falko Fend, MD, PhD a , b , c , Andreas Eicken, MD a , b , c , Rüdiger Lange, MD, PhD a , b , c

a Clinic for Cardiovascular Surgery, German Heart Center Munich, Technical University Munich, Munich, Germany
b Department of Paediatric Cardiology and Congenital Heart Disease, German Heart Center Munich, Technical University Munich, Munich, Germany
c Department of Pathology, Technical University Munich, Munich, Germany

Accepted for publication February 27, 2006.

* Address correspondence to Dr Schreiber, German Heart Center Munich, Clinic of Cardiovascular Surgery, Technical University Munich, Lazarettstrasse 36, Munich 80636, Germany (Email: schreiber{at}dhm.mhn.de).


   Abstract
Top
 Abstract
Introduction
 Patients and Methods
 Results
 Comment
 References
 
BACKGROUND: The quest for an alternative to homografts for reconstruction of the right ventricular outflow tract is ongoing. The Shelhigh No-React (NR-4000PA series) treated porcine pulmonic valve conduit (SPVC) was developed as a potential alternative.

METHODS: During a 12-month period from May 2004 to May 2005, the SPVC was implanted in 34 patients, of whom 62% were younger than 1 year. Median age at operation was 7 months (range, 5 days to 12 years). Thirteen SPCV conduits size 10, 11 size 12, 8 size 14, and 2 size 16 were initially implanted. Since May 2005, however, we have temporarily abandoned its implantation as we were concerned about a number of early failures.

RESULTS: Until November 2005, 1 early and 1 late death have occurred. Both were not conduit related. Fifteen conduits were replaced in 13 patients. Of these, 10 were size 10, 3 size 12, 2 size 14, and none size 16. Mean time to replacement of the SPVC was 313 ± 116 days. A pseudointimal peel formation and chronic inflammation with foreign-body reaction was found in all explanted conduits at all levels. The maximum of the inflammatory reaction occurred at the valvular level around the porcine tissues, with shrinkage of the valve and hemodynamic compromise. At valvular level, small punctuate calcifications were observed in 2 cases. In 6 patients an acute inflammatory component was observed. At late follow-up (mean follow-up 366 ± 102 days, 34 patient-years), echocardiography showed a mean graft gradient of 39.8 ± 29.7 mm Hg, with mild to moderate insufficiency in 4 patients.

CONCLUSIONS: Although the No-React treated valve largely resists calcification, pseudointimal peel formation was found in all explanted conduits and led to multilevel conduit stenoses. The small-sized SPVC can not be regarded as an ideal conduit for right ventricular outflow tract reconstruction.


   Introduction
Top
 Abstract
 Introduction
Patients and Methods
 Results
 Comment
 References
 
The reconstruction of the right ventricular outflow tract (RVOT) with a valved conduit is often required in congenital heart surgery, both in early infancy and in adulthood. The use of homografts has proven to give satisfactory results with regard to performance and long-term durability [1–3]. However, the reduced availability of homografts, especially small-sized homografts, and ongoing investigations into the ideal type of valved conduits have recently led to the use of the Shelhigh No-React (NR-4000PA series) (Shelhigh Inc, Union, NJ) treated porcine pulmonic valve conduit (SPVC). We were initially intrigued by its "off the shelf" availability in all sizes and knew about both its European Community and Food and Drug Administration approval.

With a mean follow-up of currently 366 ± 102 days (34 patient-years), the purpose of this study was to evaluate our single-center experience, with special focus on elucidation of graft performance.


   Patients and Methods
Top
 Abstract
 Introduction
 Patients and Methods
Results
 Comment
 References
 
The local Ethics Committee approved the retrospective study (project number 1474/06). From May 2004 to May 2005, 36 SPVC were implanted in 34 patients for RVOT reconstruction. In this interval, the SPVC was exclusively used for RVOT reconstruction in patients requiring conduits sized 10 to 16 mm. Median age at first operation was 7 months (range, 5 days to 12 years), with a median weight of 5.4 kg (range, 2.3 to 49 kg). Sixty-two percent of the patients were younger than 1 year. The patients' diagnoses are summarized in Table 1.


View this table:
[in this window]
[in a new window]
  		Table 1. Summary of Patients' Diagnoses
 
Twenty-five patients underwent primary procedures at the time of the SPVC implantation. The remainder had had as many as 3 previous surgical interventions. The types of operations and numbers of surgical procedures before SPVC implantation are summarized in Table 2.


View this table:
[in this window]
[in a new window]
  		Table 2. Types of Operations and Numbers of Surgical Procedures Before Implantation of the Shelhigh No-React Treated Porcine Pulmonic Valve Conduit
 
All patients received heparin in the early postoperative period, aiming at a partial thromboplastin time of 40 to 60 seconds. When it proved possible to use oral anticoagulation, we commenced treatment with warfarin sodium (Bristol-Myers-Squibb, New York, New York) to achieve an international normalized ratio of 2.0 to 3.0. Patients or parents were (generally) taught to use a self-testing apparatus to monitor the anticoagulation status (CoaguCheck; Roche Diagnostics, Mannheim, Germany).

Echocardiographic evaluation was carried out in all surviving patients. The studies were systematically reviewed to assess the presence of pulmonary regurgitation and to determine the mean valve gradient. The pulmonary regurgitation was classified as none (grade 0), trivial (grade 1), mild (grade 2), moderate (grade 3), or severe (grade 4) according to features of the jet, assessed with pulsed flow Doppler and color Doppler in parasternal short-axis view. Conduit stenosis was assessed by measuring the peak velocity through the valve with continuous-wave Doppler technique. Cardiac catheterization was performed before explantation of the SPVC to assess pressure gradients with additional focus on the location and extent of any conduit stenosis and to assess potential pulmonary artery growth.

Operative Technique
The Shelhigh conduit does not have to be rinsed before implantation. The conduit valve was placed as distally as possible. To avoid compression from the sternum, placement of the conduit near the midline was avoided. Both for patch enlargement of the pulmonary arteries and of the proximal connection with the right ventricle, only the SPVC material was used at initial conduit implantation.

Histologic Examination
All explanted Shelhigh conduits were available for histopathologic assessment at the Department of Pathology, Technical University Munich. Macroscopic evaluation was performed to determine the localization and extent of luminal obstruction, as well as the mobility of valve cusps and the possible presence of vegetations. The conduits were then examined in longitudinal sections parallel to the long axis, and in some cases in cross sections taken at the valvular level, and above and below the valve. Paraffin sections were routinely stained with hematoxylin and eosin and Verhoeff's van Gieson elastic tissue stain. In a subgroup of cases, immunohistochemical staining for antigens CD3, CD4, CD8 (for T-cell subsets), CD20 (B-cell subset), and CD68 (for macrophages) was performed to characterize the inflammatory infliltrate; and naphtol AS-D-chloracetate esterase (NASD) staining was used to visualize granulocytic infiltrates.

Statistical Analysis
Preoperative and postoperative data were retrospectively collected. Descriptive data for continuous variables are presented as means ± SD or as medians with ranges; categorical variables are presented as relative frequencies. Events were defined as conduit stenosis, reoperation with conduit replacement, and death. Early events were defined as events within 30 days of operation. Event-free survival was estimated using the Kaplan Meier method, with the calculation beginning after conduit implantation. Analysis was performed with SPSS 13.02 for Windows (SPSS, Chicago, Illinois).


   Results
Top
 Abstract
 Introduction
 Patients and Methods
 Results
Comment
 References
 
Mean follow-up was 366 ± 102 days, with a total of 34 patient-years in November 2005. Follow-up was complete.

The diameter of the implanted SPVC conduits ranged from 10 to 16 mm (Fig 1). Overall, 13 conduits size 10, 11 size 12, 8 size 14, and 2 size 16 were initially implanted. Figure 1 shows the conduit size in relation to body surface area [4].


Figure 1
View larger version (13K):
[in this window]
[in a new window]
  		Fig 1. Conduit size in relation to body surface area.

 
To date, 15 conduits have been replaced. The Kaplan-Meier estimate shows the time intervals to replacement with regard to conduit size (Fig 2). Note that we separated the curves in size 10 and size 12 conduits. Size 14 and 16 conduits were evaluated jointly in one curve, as the groups were each rather small (8 size 14, and 2 size 16). Reasons for replacement were stenoses in all patients, with only 1 case of acute bacterial endocarditis (bacterial vegetations and thrombus formation at the valvular cusps). In none, a significant insufficiency was noted. Indication for replacement of the SPVC were suprasystemic pressures in the right ventricle with or without tricuspid insufficiency, with or without impaired right ventricular function. In 2 patients, a previous Shelhigh conduit (both 10 mm) was replaced with another Shelhigh conduit (again 10 mm) after 92 and 107 days, respectively. In those 2 patients and in the remainder, then, a homograft was used to reconstruct the RVOT.


Figure 2
View larger version (27K):
[in this window]
[in a new window]
  		Fig 2. Time intervals to replacement with regard to conduit size (Kaplan-Meier). (Solid line = 10 mm; long-dashed line = 12 mm; short-dashed line = 14 and 16 mm.)

 
At late follow-up, echocardiography showed a mean graft gradient of 39.8 ± 29.7 mm Hg at the level of the conduit valve in the surviving patients. A mild to moderate insufficiency was seen in 4 patients. In our patient collective, no significant SPVC graft dilatation or aneurysm formation were observed.

Two patients died. The deaths were not conduit related. One patient, who initially presented with an interrupted aortic arch with severe left ventricular outflow tract obstruction, weighed 2.3 kg at the time of biventricular repair with ventricular septal defect enlargement and right ventricle–pulmonary artery conduit. He died 10 days after the procedure of a cerebral complication (edema, hypoxia). The other patient, also with an interrupted aortic arch with severe left ventricular outflow tract obstruction, weighed 2.9 kg at the time of biventricular repair with ventricular septal defect enlargement and right ventricle–pulmonary artery conduit. He died of ongoing respiratory problems 6 months later.

Histopathology
The spectrum of histopathologic changes was remarkably similar in all explanted conduits and included the following: intimal fibrosis, neointimal proliferation, and neointimal peel formation; chronic inflammation with histiocytic demarcation of the xenograft tissues, as well as a granulomatous reaction with the presence of giant cells of foreign-body type. A subset of cases showed acute granulocytic inflammation, and rarely calcifications (Fig 3).


Figure 3
View larger version (113K):
[in this window]
[in a new window]
  		Fig 3. (1 and 2) Longitudinal and transverse section of an explanted Shelhigh conduit (size 12), showing neointimal proliferation (n) throughout the length of the conduit. The valvular cusps (*) are less involved and mobile. (3) Longitudinal section at the valvular level (conduit size 14), showing complete encasement of one valvular cusp (v) by the neointimal layer. The adjacent valvular cusp (*) is less involved and mobile. (4) Longitudinal section showing the porcine valve (*) with residues of porcine myocardium (m) and vessel wall (w) mounted in a sleeve of bovine pericardium (p). The neointimal layer (n) is most pronounced within the proximal and distal parts of the conduit and less pronounced at the valvular level (Verhoeff's van Gieson elastic tissue stain x12.5). (5) Valvular cusp, completely encased by the neointimal layer (n), with fibrous contracture (*) and immobility of the valve (longitudinal section at valvular level, hematoxylin and eosin, x400). (6) Complete encasement of a valvular cusp (*) by neointima (n). The red layer (h) between the original xenograft surface and the neointima indicates histiocytic demarcation resulting in neointimal "peel formation" (longitudinal section at valvular level, immunohistochemical staining for CD-68, x200).

 
All conduits (n = 15) showed neointimal proliferation throughout the length of the conduit. In all cases, the neointimal proliferation included the valves and free valvular margins. In most cases (n = 10), the extent of neointimal formation was most prominent within the proximal and distal parts of the conduit, and less pronounced at the valvular level. However, in 5 of 15 cases (33%), the valvular cusps were completely encased by the reactive neointimal layer, with immobility, fibrous contraction and shrinkage of the valve, and a maximum of the luminal obstruction at the valvular level.

The spectrum of inflammatory changes was relatively uniform in all specimens. Chronic inflammation with a marked histiocytic component was present in all cases (n = 15) throughout the length of the conduit, with a maximum of the inflammatory involvement between the original endothelial surface of the porcine xenograft and the reactive neointimal layer. Immunohistochemistry revealed predominantly histiocytic and T-lymphocytic infiltrates, with a sparse B-lymphocytic component. The histiocytic and the granulocytic reactions were most pronounced surrounding the porcine myocardium and supravalvular vessel wall at the basis of the valves. The granulomatous and histiocytic demarcation resulted in an incomplete or complete neointimal "peel" formation in most conduits.

Eight of 15 cases (53%) additionally showed a mild to moderate acute inflammatory component with the presence of polymorphonuclear leukocytes. This acute inflammatory reaction consistently showed a predominance at the valvular level, adjacent to the residues of xenograft-myocardium. One of these 8 cases demonstrated bacterial vegetations and thrombus formation at the valvular cusps, diagnostic of acute bacterial endocarditis. The remaining 7 patients with acute inflammation of their explanted conduits showed no evidence of infection, both clinically and histopathologically, and were interpreted as having reactive inflammation in response to the xenograft rather than subclinical endocarditis.

Small calcifications were present in 4 of 15 conduits (27%), of which 2 were at the level of the proximal anastomosis. One patient showed small punctuate calcifications at the basis of the valve; and in 1 case, small calcifications were observed within the porcine stroma of the valvular cusps.


   Comment
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
References
 
As a consequence of our most recent experience, we currently opt again for either a small homograft, if available, or a downsized homograft for RVOT reconstruction. The principle of transforming an adult-sized homograft after excision of one longitudinal third, containing a cusp, into a bicuspid graft is widely known [3, 5]. Comparing the Hancock porcine conduit with homografts, Lange and colleagues [3] found that for smaller diameters (less than 15 mm), allografts exhibit no advantage over xenografts, whereas in larger diameters (15 mm or larger), allografts represent the conduit of choice for the right ventricular outflow tract. Lange and colleagues studied in total 401 patients with a follow-up of 2,593 patient-years. Conduit exchange rate was similar (p = 0.2) for xenografts and homografts with conduit diameters less than 15 mm (41% ± 9% for allografts, 30% ± 6% for xenografts), but significantly different (p = 0.02) for diameters of 15 mm or larger (60% ± 8% for allografts, 30% ± 10% for xenografts). For patients with conduit diameters less than 15 mm (n = 66, allograft; n = 94, xenograft), the median reoperation-free interval was 8.5 years for allografts compared with 6.6 years for xenografts. These findings support the speculation that durability and even type of implanted conduit for RVOT reconstruction should be seen as a less critical issue in very young patients who generally receive small conduits, as they will outgrow the conduit before degeneration occurs. The very early problems with the SPVC led us to discontinue its use.

With no doubt, the scarcity of small-sized homografts may pose a problem in the treatment of small infants. Over the years, a continuing effort was made to find substitutes for the homograft. Various conduits housing or not housing a biological valve, porcine or bovine, respectively, have been used [6–11]. The most recent Contegra, a valved bovine jugular vein conduit, has been distributed by Medtronic outside the United States since 1998. However, some groups have since reported controversial initial results [12–17]. Breymann and colleagues [12] showed at 27 months' follow-up, that the Contegra grafts were advantageous compared with homografts with respect to survival and freedom from explantation. Right to left ventricle pressure ratio and freedom from explantation were equal for Contegra conduits and homografts, with porcine xenografts (Tissuemed, Leeds, UK) xenograft performing significantly inferior. The long tube providing ample patch material facilitates proximal or distal enlargement of the right ventricular to pulmonary pathway for primary and redo RVOT reconstruction. Dave and coworkers [18] reported on 93 consecutive Contegra implantations performed between May 2001 and August 2003. Overall freedom from reintervention was 91.6% and 83.5% at 12 and 24 months, respectively. Corno and coworkers [17] showed absent or trivial valve regurgitation in 76% of the patients and mild in 24%. The transconduit pressure gradient stayed unchanged during 26.4 months (range, 1 to 56) of follow-up, with a peak pressure gradient of 17 ± 11 mm Hg and a mean gradient of 8 ± 6 mm Hg. However, early stenoses of the Contegra with extensive peel formation, insufficiency by dilatation and aneurysm formation, and thrombotic events have been reported by others at the same time [19–23].

Equally, there have been few studies including small series of patients reporting performance problems due to conduit stenosis and RVOT obstruction regarding the SPVC. Ishizaka and coworkers [24] evaluated the performance of the Shelhigh NR-4000. From February 2000 to September 2000, the SPVC was implanted 25 times in 24 patients in the RVOT. Age at operation was 2.8 ± 3.9 years, including 12 patients less than 1 year old. The median conduit size was 14 mm (range, 10 to 18 mm). Twelve conduits (48%) in 11 patients had to be removed at a median of 12 months (range, 2 to 18) owing to RVOT obstruction in 11 and conduit insufficiency with pseudoaneurysm in 1. The typical findings of the explanted conduits were prominent intimal peel formation at the distal anastomosis without calcification. The actuarial freedom from reintervention at 18 months was 48% ± 10%. The authors concluded that a SPVC with the diameter of 14mm or less has exhibited a high incidence of distal conduit stenosis due to intimal peel formation resulting in early conduit failure. These findings have led Ishizaka and colleagues [24] to abandon the use of the SPVC when other options are available. Pearl and associates [25] reported 8 patients during a 10-month period. Median age at initial operation was 9.5 days. Six conduits were less than 12 mm in diameter (range, 9 to 19 mm). During a mean follow-up of 18 months, five conduits had to be replaced at 6, 10, 12, 12, and 13 months, respectively, for severe obstruction. Actuarial conduit failure at 12 months was 72%.

In our cohort of 34 patients and 15 explanted conduits to date, the pathologic findings in all resected specimens were remarkably uniform and were consistent with previous reports. We observed neointimal proliferation and chronic inflammation throughout the length of the conduits, including the valves and free valvular margins. The extent of neointimal formation was commonly most prominent within the proximal and distal parts of the conduit and less pronounced at the valvular level, which is in accordance with previous findings by Pearl and associates [25] and Ishizaka and colleagues [24]. We observed that the inflammatory reaction was most pronounced at the valvular level surrounding remnants of porcine myocardium and vessel wall, a finding that has not been specifically mentioned in previous reports.

The obvious relationship between early graft failure and smaller graft sizes in our series may indicate the importance of flow dynamics. This causative mechanism and consecutive enhanced macrophage activation was suggested by Boudjemline and colleagues [19, 20]. The authors postulated an abrupt narrowing between the distal end of the conduit and the commonly hypoplastic pulmonary arteries, resulting in a pressure gradient with acceleration of blood flow and increased shear forces that may stimulate neointimal proliferation.

Besides flow dynamics, residual glutaraldehyde from graft conservation may have contributed to delayed endothelialization and increased thrombogenicity of the xenograft surface in our series. It is a well-described phenomenon that glutaraldehyde released from cardiac implants delays endothelialization and thus may enhance thrombogenicity and secondary macrophage activation [26, 27]. The Shelhigh conduit is processed with a special No-React aldehyde-based treatment to cross-link residual glutaraldehyde and prevent release. However, the exact in vivo function of residual glutaraldehyde and its potential role in early graft failure remains to be evaluated.

The role of host immune response as a potential cause for intimal proliferation and conduit stenosis is still not completely understood [19, 20]. Pearl and coworkers [25] observed a plasma-cell rich inflammation along the surfaces of SPVC conduits explanted because of stenosis. The authors, therefore, suggested the possibility of an immune reaction to xenograft protein as a contributing factor in prosthesis failure. In our series, the main inflammatory component in all explanted grafts was predominantly "nonspecific," including macrophages and granulocytes, although some lymphocytes (more T- than B-cell type) occurred. This finding rather suggests a predominance of a nonspecific foreign-body type reaction than specific immunologic response.

A recent report by Rieder and coworkers [28] compared the immunogenic potential of decellularized porcine and human heart valves in vitro. Decellularized porcine pulmonary valves still provoked a substantial monocytic migratory response in vitro, whereas human decellularized heart valves showed a completely nonantigenic behavior. In our series, the distribution of lesions within the explanted conduits suggests a stronger reactivity of the porcine myocardium and vessel wall as compared with the valve cusps themselves or the bovine pericardium. Although the exact role of different porcine xenogenic components, including cellular elements as well as extracellular matrix proteins, remains to be elucidated, the No-React Shelhigh conduit cannot be regarded as completely nonimmunogenic. Despite the initiation of an inflammatory and foreign-body reaction throughout the conduit, no invasion or destruction of the xenograft tissues was observed, suggesting a good conservation of the graft.

Specimens of explanted conduits were also evaluated with regard to surgical technique. The diffuse distribution of histopathologic changes throughout the length of the conduit, with infrequent involvement of the distal anastomosis suggests other than technical issues as the underlying cause for early conduit failure. The distal anastomosis of the Shelhigh conduit was performed using a fine 6-0 or 7-0 continuous polypropylene suture. The small size of the distal pulmonary arteries in our patient group (75% with a body surface area < 0.5) highlights the importance of a careful suturing technique. Intima to intima contact must be achieved. Since creating an everting suture line by suturing from outside the vessel can be technically impractical and cumbersome, we applied a technique of internal inverting suture. Here, with deep bites taken on the intima and shallow bites on the adventitia intimal alignement is achieved [29].

The surgical implantation manual (Shelhigh) is not conclusive on the exact antiplatelet aggregation therapy after implantation of the SPVC. As described, we have opted for early postoperative heparinization in all patients, aiming at a partial thromboplastin time of 40 to 60 seconds. Subsequently, we commenced treatment with warfarin sodium in all patients. The aim was to achieve an international normalized ratio of 2.0 to 3.0 for at least 3 months [30]. Patients, or parents, were generally taught to use a self-testing apparatus. In contrast to our protocol, Ishizaka and colleagues [24] and Pearl and associates [25] administered only low-dose aspirin.

To conclude, the No-React–treated valve largely resists calcification; however, pseudointimal peel formation was found in all explanted conduits and led to multilevel conduit stenoses. Although the exact role of different porcine xenogenic components, including cellular elements as well as extracellular matrix proteins, remains to be elucidated, the SPVC conduit cannot be regarded as completely nonimmunogenic. The small-sized SPVC cannot be regarded as an ideal conduit for RVOT reconstruction.


   References
Top
 Abstract
 Introduction
 Patients and Methods
 Results
 Comment
 References
 

  1. Stark J. The use of valved conduits in pediatric cardiac surgery Pediatr Cardiol 1998;19:282-288.[Medline]
  2. Homann M, Haehnel JC, Mendler N, et al. Reconstruction of the RVOT with valved biological conduits25 years experience with allografts and xenografts. Eur J Cardiothorac Surg 2000;17:624-630.[Abstract/Free Full Text]
  3. 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):365-367.
  4. Du Bois D, Du Bois EF. A formula to estimate the approximate surface area if height and weight be known Nutrition 1989;5:303-311.[Medline]
  5. Michler RE, Chen JM, Quaegebeur JM. Novel technique for extending the use of allografts in cardiac operations Ann Thorac Surg 1994;57:83-87.[Abstract]
  6. Vrandecic MO, Fantini FA, Gontijo BF, Nunes Martins C, Vrandecic E. Porcine stentless valve/bovine pericardial conduit for right ventricle to pulmonary artery Ann Thorac Surg 1998;66(Suppl):179-182.
  7. Schlichter AJ, Kreutzer C, Mayorquim RC, et al. Five- to fifteen-year follow-up of fresh autologous pericardial valved conduits J Thorac Cardiovasc Surg 2000;119:869-879.[Abstract/Free Full Text]
  8. Chard RB, Kang N, Andrews DR, Nunn GR. Use of the Medtronic Freestyle valve as a right ventricular to pulmonary artery conduit Ann Thorac Surg 2001;71(Suppl):361-364.[Free Full Text]
  9. Levine AJ, Miller PA, Stumper OS, et al. Early results of right ventricular-pulmonary artery conduits in patients under 1 year of age Eur J Cardiothorac Surg 2001;19:122-126.[Abstract/Free Full Text]
  10. Kanter KR, Budde JM, Parks WJ, et al. One hundred pulmonary valve replacements in children after relief of right ventricular outflow tract obstruction Ann Thorac Surg 2002;73:1801-1807.[Abstract/Free Full Text]
  11. Takabayashi S, Kado H, Shiokawa Y, Fukae K, Nakano T. Modified Ross procedure using a conduit with a synthetic valve Eur J Cardiothorac Surg 2004;26:1087-1091.[Abstract/Free Full Text]
  12. Breymann T, Thies WR, Boethig D, Goerg R, Blanz U, Koerfer R. Bovine valved venous xenografts for RVOT reconstructionresults after 71 implantations. Eur J Cardiothorac Surg 2002;21:703-710.[Abstract/Free Full Text]
  13. Bove T, Demanet H, Wauthy P, et al. Early results of valved bovine jugular vein conduit versus bicuspid homograft for right ventricular outflow tract reconstruction Ann Thorac Surg 2002;74:536-541.[Abstract/Free Full Text]
  14. Corno AF, Hurni M, Griffin H, et al. Bovine jugular vein as right ventricle-to-pulmonary artery valved conduit J Heart Valve Dis 2002;11:242-248.[Medline]
  15. Carrel T, Berdat P, Pavlovic M, Pfammatter JP. The bovine jugular veina totally integrated valved conduit to repair the right ventricular outflow. J Heart Valve Dis 2002;11:552-556.[Medline]
  16. Erek E, Yalcinbas YK, Salihoglu E, et al. Fate of stentless bioprostheses on right side of the heart Asian Cardiovasc Thorac Ann 2003;11:58-62.[Abstract/Free Full Text]
  17. Corno AF, Qanadli SD, Sekarski N, et al. Bovine valved xenograft in pulmonary positionmedium-term follow-up with excellent hemodynamics and freedom from calcification. Ann Thorac Surg 2004;78:1382-1388.[Abstract/Free Full Text]
  18. Dave HH, Kadner A, Berger F, et al. Early results of the bovine jugular vein graft used for reconstruction of the right ventricular outflow tract Ann Thorac Surg 2005;79:618-624.[Abstract/Free Full Text]
  19. Boudjemline Y, Bonnet D, Agnoletti G, Vouhe P. Aneurysm of the right ventricular outflow following bovine valved venous conduit insertion Eur J Cardiothorac Surg 2003;23:122-124.[Abstract/Free Full Text]
  20. Boudjemline Y, Bonnet D, Massih TA, et al. Use of bovine jugular vein to reconstruct the right ventricular outflow tractearly results. J Thorac Cardiovasc Surg 2003;126:490-497.[Abstract/Free Full Text]
  21. Tiete AR, Sachweh JS, Roemer U, Kozlik-Feldmann R, Reichart B, Daebritz SH. Right ventricular outflow tract reconstruction with the Contegra bovine jugular vein conduita word of caution. Ann Thorac Surg 2004;77:2151-2156.[Abstract/Free Full Text]
  22. Gober V, Berdat P, Pavlovic M, Pfammatter JP, Carrel TP. Adverse mid-term outcome following RVOT reconstruction using the Contegra valved bovine jugular vein Ann Thorac Surg 2005;79:625-631.[Abstract/Free Full Text]
  23. Meyns B, Van Garsse L, Boshoff D, et al. The Contegra conduit in the right ventricular outflow tract induces supravalvular stenosis J Thorac Cardiovasc Surg 2004;128:834-840.[Abstract/Free Full Text]
  24. Ishizaka T, Ohye RG, Goldberg CS, et al. Premature failure of small-sized Shelhigh No-React porcine pulmonic valve conduit model NR-4000 Eur J Cardiothorac Surg 2003;23:715-718.[Abstract/Free Full Text]
  25. Pearl JM, Cooper DS, Bove KE, Manning PB. Early failure of the Shelhigh pulmonary valve conduit in infants Ann Thorac Surg 2002;74:542-548.[Abstract/Free Full Text]
  26. Chang Y, Tsai CC, Liang HC, Sung HW. Reconstruction of the right ventricular outflow tract with a bovine jugular vein graft fixed with a naturally occurring crosslinking agent (genipin) in a canine model J Thorac Cardiovasc Surg 2001;122:1208-1218.[Abstract/Free Full Text]
  27. Mosquera DA, Goldman M. Endothelial cell seeding Br J Surg 1991;78:656-660.[Medline]
  28. Rieder E, Seebacher G, Kasimir MT, et al. Tissue engineering of heart valvesdecellularized porcine and human valve scaffolds differ importantly in residual potential to attract monocytic cells. Circulation 2005;111:2792-2797.[Abstract/Free Full Text]
  29. Jonas RA. Surgical technique Comprehensive surgical management of congenital heart disease. New York: Oxford University Press; 2004. pp. 13-28.
  30. Salem DN, Stein PD, Al-Ahmad A, et al. Antithrombotic therapy in valvular heart disease–native and prostheticthe Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy. Chest 2004;126(Suppl):457-482.[Abstract/Free Full Text]



This article has been cited by other articles:


Home page
 J. Thorac. Cardiovasc. Surg.Home page
M. Ando and Y. Takahashi
Ten-year experience with handmade trileaflet polytetrafluoroethylene valved conduit used for pulmonary reconstruction.
J. Thorac. Cardiovasc. Surg., January 1, 2009; 137(1): 124 - 131.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
C. Schreiber, A. Eicken, S. Seidl, and R. Lange
Unexpected Early Failure of a Decellularized Right Ventricle to Pulmonary Artery Graft
Ann. Thorac. Surg., December 1, 2008; 86(6): 2026 - 2027.
[Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
T. M. Ashcraft, K. Jones, W. L. Border, P. Eghtesady, J. M. Pearl, P. R. Khoury, and P. B. Manning
Factors Affecting Long-Term Risk of Aortic Arch Recoarctation After the Norwood Procedure
Ann. Thorac. Surg., April 1, 2008; 85(4): 1397 - 1402.
[Abstract] [Full Text] [PDF]

Home page
 Eur. J. Cardiothorac. Surg.Home page
L. Englberger, J. Noti, F. F. Immer, M. Stalder, F. S. Eckstein, and T. P. Carrel
The Shelhigh No-React(R) bovine internal mammary artery: a questionable alternative conduit in coronary bypass surgery?
Eur. J. Cardiothorac. Surg., February 1, 2008; 33(2): 222 - 224.
[Abstract] [Full Text] [PDF]

Home page
 ICVTSHome page
T. Miyazaki, M. Yamagishi, K. Shuntoh, and H. Yaku
An expanded polytetrafluoroethylene-autologous aortic hybrid valve for right ventricular outflow tract reconstruction in the Ross procedure
Interactive CardioVascular and Thoracic Surgery, April 1, 2007; 6(2): 163 - 166.
[Abstract] [Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
C. F. Marcelletti
My View and My Experience on Extracardiac RV-PA Conduit
Ann. Thorac. Surg., February 1, 2007; 83(2): 726 - 726.
[Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
J. Horer, A. Eicken, and C. Schreiber
Reply
Ann. Thorac. Surg., February 1, 2007; 83(2): 726 - 727.
[Full Text] [PDF]

Home page
 Ann. Thorac. Surg.Home page
A. Dodge-Khatami
Invited commentary.
Ann. Thorac. Surg., July 1, 2006; 82(1): 185 - 186.
[Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to Personal Folders
Right arrow Download to citation manager
Right arrow Author home page(s):
Christian Schreiber
Martin Kostolny
Julie Cleuziou
Klaus Holper
Right arrow Permission Requests
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Schreiber, C.
Right arrow Articles by Lange, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Schreiber, C.
Right arrow Articles by Lange, R.
Related Collections
Right arrow Congenital - cyanotic

HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
ANN THORAC SURG ASIAN CARDIOVASC THORAC ANN EUR J CARDIOTHORAC SURG
J THORAC CARDIOVASC SURG ICVTS ALL CTSNet JOURNALS