Conduit Replacement Research Articles

Evolving Microbiology and Treatment of Extracavitary Prosthetic Graft Infections

The authors report the microbiology and outcomes following an individualized treatment algorithm for extracavitary (EC) prosthetic graft infection, including the use of graft preservation and in situ graft replacement techniques. A retrospective 8-year review of 87 patients treated for EC prosthetic graft infections was carried out. The treatment algorithm included culture-specific antibiotic therapy, surgical site debridement with antibiotic bead placement, selected graft preservation with muscle flap coverage, or graft excision with in situ conduit replacement. Outcomes measured included death, limb loss, and recurrent infection. It was found that present-day management of EC prosthetic graft infections is associated with lower mortality and morbidity despite changes in microbiology and the increased application of graft preservation and in situ grafting treatments.

Survival and reintervention after neonatal repair of truncus arteriosus with valved conduit

Neonatal primary repair has progressively become the treatment of choice for truncus arteriosus with encouraging survival. However, use of valved conduits to reconstruct the right ventricular outflow tract (RVOT) inevitably induces reintervention. This study estimates survival and rate of catheter-interventional and surgical reinterventions. Thirty-five consecutive neonates who underwent truncus repair with 27 homografts and 8 Contegras from 1987 to 2007 were studied. Interrupted aortic arch (IAA) was associated in nine patients. Actuarial survival and freedom from reintervention were evaluated according to Kaplan-Meier method. Five patients died early after repair. Two died late and one death was related to reintervention. Survival was 91.9%+/-5.4% from postoperative month 2 onwards when IAA was not associated and 41.7%+/-17.3% from month 4 in IAA presence. During a median follow-up of 68 months (range 1-180 months), 42 reinterventions (of which 17 reoperations) were performed in 21 patients. Rate of reintervention was 2.6 per early survivor per 10 years. RVOT obstruction constituted the main indication: branch pulmonary arteries often being involved (n=25). Uncommon indication was subaortic stenosis (n=3), aortic arch obstruction (n=2) and truncal valve regurgitation (n=2). At year 10, freedom from first, second and third reintervention was 17.9 %+/-8.1%, 46.1%+/-10.6% and 81.9%+/-9.5%, respectively. Sixteen first conduits were explanted. Freedom from first conduit replacement was 87.5%+/-6.8%, 64.1%+/-10.2% and 39.5%+/-10.7% at year 1, 3 and 5, respectively. Homografts enjoyed higher durability than Contegras. Neonatal repair of truncus arteriosus results in high survival, the only risk being IAA association. The rate of reintervention is heavily influenced by stenosis of branch pulmonary arteries.

Modified Bentall procedure – ‘a collar technique’ to control bleeding from coronary ostia anastomoses

Composite conduit aortic root replacement has become widely accepted as the preferred treatment for ascending aorta aneurysm and dissection. We present a patient in whom creation of 'buttons' was impossible due to fragility of the ascending aorta wall. The distal anastomosis was made to the transected aorta. The remnant of the proximal ascending aortic wall was fully transected 8-9 mm above the upper edge of coronary ostia anastomoses (incorporated into conduit using inclusion technique), thus forming a 'collar' around the proximal part of the conduit. At the end of the procedure the 'collar' was anchored to the conduit to control persistent bleeding from coronary ostia anastomoses.

Hypoxic remodelling of Ca2+ signalling in proliferating human arterial smooth muscle

Ca(2+) homeostasis in proliferating smooth muscle (SM) cells strongly influences neointima formation, which can cause failure of coronary artery bypass surgery. During surgical procedures and subsequent revascularization, SM cells are also exposed to a period of hypoxia. Problems with bypass surgery in general involve neointima formation which is in turn dependent on SM proliferation and migration. Here, we have directly monitored [Ca(2+)](i) fluorimetrically in proliferating internal mammary artery (IMA) SM cells, and investigated how this is modulated by chronic hypoxia (CH; 24 h, 2.5% O(2)). IMA is the most successful replacement conduit vessel in bypass grafts. Basal [Ca(2+)](i) was unaffected by CH, but removal of extracellular Ca(2+) evoked far smaller reductions in [Ca(2+)](i) than were seen in normoxic cells. Voltage-gated Ca(2+) entry was suppressed in CH cells, and this was attributable to activation of the transcriptional regulator, hypoxia inducible factor. Furthermore, the relative contributions to voltage-gated Ca(2+) entry of L- and T-type Ca(2+) channels was markedly altered, with T-type channels becoming functionally more important in CH cells. Agonist-evoked mobilization of Ca(2+) from intracellular stores was not affected by CH, whilst subsequent capacitative Ca(2+) entry was modestly suppressed. Our data provide novel observations of the remodelling of Ca(2+) homeostasis by CH in IMASM cells which may contribute to their superior patency as coronary bypass grafts.

Determinants of Right Ventricular Outflow Tract Conduit Longevity: A Multinational Analysis

The need for conduit replacement in the growing child remains a major problem after right ventricular outflow tract reconstruction. We compared two diverse surgical centers with considerable practice variation in Europe and the United States to identify modifiable risk factors that can increase conduit longevity. Retrospective analysis of 194 patients (56 Europe, 138 United States) who underwent primary right ventricular to pulmonary artery conduit placement between January 1987 and March 2003. Diagnoses included tetralogy of Fallot with pulmonary atresia, truncus arteriosus, transposition of the great arteries with ventricular septal defect and pulmonary stenosis, and double-outlet right ventricle. Median age was 7.3 months (range 2 days-29.9 years). Types of conduits included aortic homografts (n = 111), pulmonary homografts (n = 48), Contegra conduits (Medtronic, Inc, Minneapolis, MN) (n = 23), and synthetic conduits (n = 12). Freedom from conduit failure at 5 years was 50% (58% Europe, 48% United States, P = NS). On multivariate analysis, smaller conduit diameter (hazard ratio [HR] 1.15, P < .001) and conduits other than pulmonary homografts (synthetic conduits [HR 3.17, P = .01], Contegra conduits [HR 2.80, P = .02], aortic homografts [HR 1.56, P = .05]) predicted shorter time to conduit failure. In addition, time to failure was longer for patients undergoing transcatheter intervention. Different surgical techniques in conduit preparation and insertion did not influence conduit longevity. Analysis of the two diverse surgical centers showed that to increase conduit longevity, one should choose the largest possible conduit, use a pulmonary homograft, and consider children whose conduits develop obstruction as candidates for transcatheter intervention.

Jugular venous valved conduit (Contegra®) matches allograft performance in infant truncus arteriosus repair☆

Limited availability and durability of allograft conduits require that alternatives be considered. We compared bovine jugular venous valved (JVV) and allograft conduit performance in 107 infants who survived truncus arteriosus repair. Children were prospectively recruited between 2003 and 2007 from 17 institutions. The median z-score for JVV (n=27, all 12 mm) was +2.1 (range +1.2 to +3.2) and allograft (n=80, 9-15mm) was +1.7 (range -0.4 to +3.6). Propensity-adjusted comparison of conduit survival was undertaken using parametric risk-hazard analysis and competing risks techniques. All available echocardiograms (n=745) were used to model deterioration of conduit function in regression equations adjusted for repeated measures. Overall conduit survival was 64+/-9% at 3 years. Conduit replacement was for conduit stenosis (n=16) and/or pulmonary artery stenosis (n=18) or regurgitation (n=1). The propensity-adjusted 3-year freedom from replacement for in-conduit stenosis was 96+/-4% for JVV and 69+/-8% for allograft (p=0.05). The risk of intervention or replacement for branch pulmonary artery stenosis was similar for JVV and allograft. Smaller conduit z-score predicted poor conduit performance (p<0.01) with best outcome between +1 and +3. Although JVV conduits were a uniform diameter, their z-score more consistently matched this ideal. JVV exhibited a non-significant trend towards slower progression of conduit regurgitation and peak right ventricular outflow tract (RVOT) gradient. In addition, catheter intervention was more successful at slowing subsequent gradient progression in children with JVV versus those with allograft (p<0.01). JVV does match allograft performance and may be advantageous. It is an appropriate first choice for repair of truncus arteriosus, and perhaps other small infants requiring RVOT reconstruction.

The Right Gastroepiploic Artery: An Independent Risk for Leak Post Oesophageal Resection

Numerous different operations exist for the treatment of oesophageal cancer, Ivor-Lewis, McKeown, and left thoracophrenotomy* being the most common. All rely on the stomach being utilised as a replacement conduit in the chest. To achieve this, the left gastric artery, a variable amount of the lesser curve (depending on individual surgeon preferences) and the short gastric arteries are divided. This enables the stomach to be swung up into the chest, relying on the gastroduodenal artery and then the right gastroepiploic artery to supply the fundus where the anastomosis takes place. Atheroma and size variability (diameter 2.0–3.5 mm, results in 9.4 times difference in flow by Poiseuille's law) of the right gastroepiploic artery is known from cardiac surgery where it is utilised as a bypass graft.1 This could potentially limit the blood supply at the anastomosis, increasing the chances of a leak postoperatively. [*Thoracophrenotomy = Thoracotomy and division of diaphragm.]

Hypotension Following Cardiac Surgery Associated with Paroxetine and Mirtazapine Withdrawal

This case describes a 15-year-old patient who experienced postoperative hypotension following an elective Ross procedure for aortic stenosis/insufficiency. The patient was taking paroxetine and mirtazapine for depression which were held prior to surgery. Hypotension occurred approximately eight hours postoperatively and required vasopressor support. Upon reinitiation of antidepressant therapy, hypotension resolved and vasopressor support was discontinued. A year later the patient required conduit replacement, and antidepressant therapy was weaned off during the three weeks prior to surgery. No hypotension was observed following the second surgery. Paroxetine withdrawal has been well-documented within adult literature, but there is little information regarding mirtazapine withdrawal. Furthermore, cardiovascular effects have not been well-documented, and even less is known within the pediatric population. Withdrawal symptoms in these agents may be explained by cholinergic rebound and/or rapid decline in serum concentrations upon abrupt discontinuation. It may be reasonable to consider tapering antidepressants with short half-lives prior to elective surgery in which patients may not be able to take maintenance medications for more than 24 hours.

Substrate Mapping and Catheter Ablation of Ventricular Tachycardia after Right Ventriculotomy

Tetralogy of Fallot is one of the most common forms of cyanotic congenital heart disease, estimated to occur in 0.26 per 1000 live births.1 Long-term survival depends on definitive surgery; happily, survival after complete repair can now be expected in 98% of cases. Initial surgery may be palliative with the placement of a shunt, but complete repair is now offered in infancy with the expectation of survival well into adulthood. Although tetralogy patients occasionally require permanent pacemakers for atrioventricular block, and many will need to undergo periodic pulmonic valve and conduit replacement, by far the most worrisome problem such patients face is the prospect of sudden death. In the early days of corrective surgery, when this catastrophic outcome was first observed, it was initially hypothesized that atrioventricular block might be responsible.2 Subsequently, attention shifted to the problem of malignant ventricular arrhythmias.3 It is now widely accepted that ventricular tachycardia in such patients is the likely cause of sudden death and is likely to be macroreentrant in nature. Article p 2241 Although clear risk factors within the tetralogy population …

Intraoperative Pulmonary Artery Stenting: An Alternative Technique for the Management of Pulmonary Artery Stenosis

Pulmonary artery reconstruction remains a challenging clinical problem. We sought to evaluate the use of intraoperative stenting in conjunction with open heart surgical repairs. We retrospectively analyzed data from 22 patients between 1998 and 2003 who underwent intraoperative pulmonary artery stenting. The mean age was 9.3 years (range, 9 months to 24 years). The left pulmonary artery was stented in 8 patients, the right in 13, the main in 1, and bilateral in 1. Available echocardiograms in 20 patients revealed a mean preoperative diameter of 7.6 mm (range, 3 to 16.5 mm) and a mean peak gradient of 45.4 mm Hg (range, 20 to 120 mm Hg). Augmentation patch angioplasty of the contralateral pulmonary artery was performed in 11 patients. Thirteen patients had pulmonary valve replacement and 11 had conduit replacement or augmentation. Three patients underwent tricuspid valve repair, 6 had Fontan, and 4 underwent a modified Maze procedure. Follow-up echocardiograms demonstrated a decrease in mean peak gradient to 4.3 mm Hg (range, 0 to 15 mm Hg), a change in mean peak gradient of 41.1 mm Hg (93% reduction). After stenting the mean pulmonary artery diameter increased to 10.9 mm (range, 6 to 17.9 mm). There was no perioperative mortality. At a mean follow-up of 22.8 months (range, 6 to 57 months), there were no surgical or percutaneous reinterventions. Intraoperative pulmonary artery stenting is a safe and effective technique that can be used as an alternative to patch angioplasty. Close follow-up is needed to examine the long-term outcome of this procedure, with special attention to the growth and development of the stented vessel.

Compared fate of small-diameter Contegras® and homografts in the pulmonary position

This study analyzes whether small-diameter Contegras behave in the same way as small-diameter homografts, when implanted for the first time in pulmonary position. Small-diameter conduits include 12 and 14 mm Contegras and 8-14 mm homografts. Graft dysfunction is defined as right ventricular outflow tract obstruction with peak echo-Doppler gradient>40 mmHg, or grade III/IV graft regurgitation. Graft failure is defined as need for conduit replacement or need for catheter or surgical reintervention. Thirty-eight patients who received small Contegras (n=25) and small homografts (n=13) from October 2002 to end December 2006 were studied. The most frequent indication was pulmonary atresia and ventricular septal defect (n=20; 10 associated with major aorto-pulmonary collateral arteries), followed by truncus arteriosus (n=12). Most patients' characteristics were comparable except that recipients of homografts were smaller (p for body area=0.014). Survival, freedom from graft dysfunction, failure and explantation were estimated by the Kaplan-Meier method. The log-rank test was used to compare outcomes. There were three early and four late deaths. No death was graft related. Survival was 80+/-8.2% for patients with Contegras and 77+/-11.7% for those with allografts: p=0.82. Mean follow-up duration is 22+/-16 months. Freedom from dysfunction for Contegras conduits decreased in the first 6 months and stabilized at 58+/-11% from month 14. For homografts it decreased only 1 year after implantation, down to 35+/-19.7% from month 31: p=0.61. Freedom from Contegras failure diminished the first 16 months to level out at 57+/-13%. No homograft failed the first 2 years. With a p-value of 0.14, homografts tended to fail less frequently. Five grafts were explanted. Freedom from explantation was similar (p=0.98): 90+/-6.7% for Contegras and 75+/-21.6% for homografts at year 3. In the first 4 years after pulmonary implantation of small-diameter Contegras and homografts, the fate of both conduits was statistically similar, in spite of different behavior. As Contegras is 'off-the-shelf' available, it constitutes a sound alternative to homograft for right ventricular outflow tract reconstruction in neonates and infants.

Combined pedicled antropyloroplasty and gastric pull-up reconstruction for corrosive esophagogastric stricture

Combined pedicled antropyloroplasty and gastric pull-up reconstruction for corrosive esophagogastric stricture

Long-Term Results After the Rastelli Repair for Transposition of the Great Arteries

This study sought to assess risk factors for late mortality after the Rastelli operation for patients with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction. Records of 39 patients who underwent the Rastelli operation between 1977 and 2004 were reviewed. Median age at the time of operation was 5.1 years (2.2 years within the last 5 years). There were no early deaths. During a median follow-up of 8.9 years (range, 0 to 25 years), 2 patients died of sudden death, 1 of pneumonia, 1 during reoperation, and 2 received heart transplantation. Freedom from death or transplantation was 93.8% +/- 4.3% and 57.5% +/- 15.1% at 10 and 20 years, respectively. Freedom from conduit replacement was 48.8% +/- 10.3% and 32.5% +/- 10.3% at 10 and 20 years, respectively. Subvalvular and valvular left ventricular outflow tract obstruction (p = 0.012), stenosis of the peripheral pulmonary arteries (p < 0.001), enlargement of the ventricular septal defect (p = 0.030), and longer ischemic time (p = 0.015) were predictive for death or transplantation. Patients younger than 4 years at the time of the Rastelli operation showed a trend toward a better freedom from death or transplantation (p = 0.068), but needed significantly more conduit replacements (p = 0.038) compared with patients 4 years or older. The Rastelli operation is a low-risk procedure with regard to early mortality. The status of the pulmonary arteries and ventricular septal defect enlargement are predictive for long-term survival. Patients 4 years of age or older at the time of the Rastelli operation require fewer reoperations for conduit exchange. Nevertheless, early Rastelli repair is recommended because patients 4 years or older are at risk for a higher long-term mortality.

Xenograft Transplantation in Congenital Cardiac Surgery at Baskent University: Midterm Results

Objective Xenograft valved conduits have been used in several cardiac pathologies. In this study we have presented our midterm results of pediatric patients pathologies who were operated with xenograft conduits. Patients and Methods Between January 1999 and January 2005, 134 patients underwent open heart surgery with xenograft conduits. The conduits were used to establish the continuity of the right ventricle to the pulmonary artery or aorta, the left ventricle to the pulmonary artery, or aorta due to various types of complex cardiac anomalies. Patients were evaluated by transthoracic echocardiography (ECHO) at 6-month follow-ups. Cardiac catheterization was performed when ECHO demonstrated significant conduit failure. Results Hospital mortality was observed in 28 patients (20.1%), and 13 patients died upon follow-up (9.7%). Mean follow-up was 24.6 ± 4 months (range, 13 to 85 months). Among 93 survivors 20 patients (21.5%) were reoperated due to conduit failure. The main reasons for conduit failure were stenosis ( n = 13), valvular regurgitation ( n = 2), or both conditions in 5 cases. Mean pulmonary gradient before conduit re-replacement was 47.7 ± 30.1 mmHg. The 1-, 3-, and 6-year actuarial survival rates were 95 ± 2%, 91 ± 3%, and 86 ± 5%. The 1-, 3-, and 6-year actuarial freedom rates from reoperation were 95 ± 1%, 90 ± 3%, and 86 ± 4%. An increased gradient between the pulmonary artery and the right ventricle and prolonged cardiopulmonary bypass times were observed to be significant risk factors for reoperation. There was no mortality among reoperated patients. Conclusion Xenograft conduits should be closely followed for calcification and stenosis. Conduit stenosis is the major risk factor for reoperation. In these patients, reoperation for conduit replacement can be performed safely before deterioration of cardiac performance.

Aortic Root Translocation Plus Arterial Switch for Transposition of the Great Arteries With Left Ventricular Outflow Tract Obstruction: Intermediate-Term Results

The goal of our study was to report our intermediate-term results with aortic root translocation plus arterial switch for d-transposition of the great arteries with left ventricular outflow tract obstruction. A d-transposition of the great arteries with left ventricular outflow tract obstruction represents a difficult surgical problem. The Rastelli procedure is the usual approach to this condition. However, recurrent left ventricular outflow tract obstruction and early conduit obstruction as well as arrhythmias and troublesome late mortality are significant limitations. From 1993 to 2005, 11 children (8 male, 3 female) ages 1 month to 11 years (median age 7 months) have undergone aortic root autograft translocation plus arterial switch to correct d-transposition of the great arteries with left ventricular outflow tract obstruction. The native aortic root was excised from the right ventricle infundibulum and inserted into the left ventricular outflow, enlarging the outflow tract by resecting the outlet septum and an appropriate-size ventricular septal defect patch. After coronary artery reimplantation, right ventricular outflow reconstruction was achieved with a homograft. There were no early or late deaths. With a median follow-up of 59 months (range 2 to 137 months), 5 patients required 6 conduit replacement procedures at a median time of 53 months. Two patients required an implantable defibrillator for ventricular arrhythmias. None of the patients have developed left ventricular outflow tract obstruction. Aortic root autograft plus arterial switch procedure is a good option for the surgical management of infants and children with d-transposition of the great arteries and left ventricular outflow tract obstruction and results in a more anatomic repair compared with Rastelli operation. Intermediate-term results indicate good relief of left ventricular outflow tract obstruction and need for conduit replacement compares favorably with the Rastelli procedure for this lesion.

Truncus Arteriosus Communis: Early and Midterm Results of Early Primary Repair

Repair of truncus arteriosus communis (TAC) in the neonatal and early infant period has become standard practice in many centers. We report our experience on early primary repair of TAC, with a focus on early and midterm results. From July 1993 to December 2005, 29 patients with median age 28 days (range, 11 to 127), and median body weight 3.1 kg (range, 2.6 to 5.9 kg), underwent primary repair of TAC. The anatomical type of TAC was as follows: A1-2, 27; A3, 0; and A4, 2. Right ventricular outflow tract was reconstructed with an aortic (n = 7) or pulmonary homograft (n = 8), or a bovine (n = 11) or porcine valved xenograft (n = 3). Follow-up was complete for all patients. Hospital mortality was 3.4% (1 death due to respiratory infection). At a mean follow-up of 74 months (range, 2 to 149), 1 patient died suddenly 2 months after surgery (6-year actuarial survival 93%). Of the 27 midterm survivors, 14 (52%) underwent 30 interventional procedures including percutaneous balloon dilation with or without stenting for right ventricular outflow tract or branch pulmonary artery obstruction. Eight of them were reoperated on for right ventricle-to-pulmonary artery conduit replacement (n = 8, 23%), and aortic valve regurgitation (n = 1, 3.4%). The overall freedom from any reintervention at 6 years was 50%. Aortic valve regurgitation was trace in 15 patients, mild in 8, moderate in 4. All midterm survivors but 1 (26 of 27) had good ventricular function. Truncus arteriosus communis repair can be performed early with very low perioperative mortality and satisfactory midterm morbidity; the latter is mainly attributed to right ventricular outflow tract reconstruction. Interventional cardiac catheterization delays inevitable conduit replacement.

The Ross-Konno Procedure in Children: Outcomes, Autograft and Allograft Function, and Reoperations

The Ross aortic valve replacement with a modified Konno-type enlargement Ross-Konno procedure of the aortic annulus and subannular region allows an autograft aortic valve replacement for children with significant annular and subannular hypoplasia. The potential for growth and the proven durability of the autograft make the Ross-Konno procedure an ideal aortic valve replacement for this subgroup with multilevel left ventricular outflow tract obstruction. We reviewed our institutional midterm experience to assess autograft and homograft hemodynamics, and management after a Ross-Konno procedure. Between 1995 and 2005, 14 consecutive children (mean age, 6.4 +/- 5.9 years; range, 1 month to 17 years) underwent the Ross-Konno procedure. All children had severe to critical aortic stenosis or multilevel left ventricular outflow tract obstruction. There was 1 early and 1 late death with a mean follow-up of 5.7 +/- 3.6 years. Actuarial survival at 10 years was 86%. Three patients underwent right ventricular outflow tract reoperation for conduit replacement for homograft dysfunction and one patient required redo aortic root replacement with a mechanical valves for progressive aortic insufficiency. Freedom from right ventricular outflow tract and autograft reoperation at 10 years is 77% and 92%, respectively. Aortic annular dilation was not observed in all patients. Univariate and multivariate analysis identified no risk factors for autograft or homograft valve-related reoperation. The Ross-Konno procedure is an excellent technique to treat complex multilevel left ventricular outflow tract obstruction in children with significant annular and subannular hypoplasia. The autograft demonstrated durability without development of aortic stenosis or progressive dilation and a low incidence of developing progressive aortic insufficiency. Enlargement of the aortic annulus appear to parallel somatic growth in most instances.

Invited commentary

Although enhanced knowledge and technological advances are making the total correction for the majority of congenital heart defects routine and safe, either the initial implantation of a biological valved conduit or conduit replacement inevitably lead to repeat surgery and represent one of the more frustrating issues of our field in need of a long-term solution. For reconstruction of the right ventricular outflow tract, valved homograft conduits have the best track record and are considered the gold standard. However, for small patients, small sized homografts are scarce and even when larger ones can be downsized (ie, bicuspidized), they present limitations with regards to patient-conduit size mismatch and resistance to degeneration, and they fare as poorly as other known xenograft valves. The current article [1Schreiber C. Sassen S. Kostolny M. et al.Early graft failure of small-sized porcine-valved conduits in reconstruction of the right ventricular outflow tract.Ann Thorac Surg. 2006; 82: 179-186Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar] is the third clinical report on the Shelhigh No-React porcine-valved conduit, confirming the poor results already observed by others [2Ishizaka T. Ohye R.G. Goldberg C.S. et al.Premature failure of small-sized Shelhigh No-React porcine pulmonic valve conduit model NR-4000.Eur J Cardiothoracic Surg. 2003; 23: 715-718Crossref PubMed Scopus (34) Google Scholar, 3Pearl J.M. Cooper D.S. Bove K.E. Manning P.B. Early failure of the Shelhigh pulmonary valve conduit in infants.Ann Thorac Surg. 2002; 74: 542-548Abstract Full Text Full Text PDF PubMed Scopus (30) Google Scholar], which lead the authors to abandon implantation in their own practice, and to discourage the use of this conduit by others. The fact that 62% of their patients were under 1 year of age illustrates the problem known to us all in finding appropriately sized small homografts, and this justifies their trial to find a better and more practical “off the shelf” alternative. However, just as with other xenografts, the authors found that the Shelhigh No-React formed an extensive neointimal peel leading to early conduit stenosis and failure, although gross calcification was not noted. Despite efforts by the manufacturers to produce a nonimmunogenic product, the presence of a nonspecific macrophage and granulocyte-mediated inflammatory response still pointed to a foreign-body reaction. Therefore, the concerns and condemnation of this conduit by the authors are validly argued and well illustrate the ongoing search for an ideal alternative to reconstruct the right ventricular outflow tract. Accordingly the inevitable life-long threat of multiple reoperations for any given patient and the associated risks continue to motivate many research groups to focus their efforts on the quest for the tissue-engineered grail (ie, the “perfect biological valve”). Curiously the authors gave no justification for full heparinization followed by oral anticoagulation to an international normalized ratio of 2 to 3 for at least 3 months, and they did not state if some patients eventually required longer anticoagulation and for which reasons. Most centers would agree that unless a proven advantage in terms of patient benefit or conduit longevity or both can be demonstrated with this practice, anticoagulation could and should be avoided for biological implants.

Optimal Management Strategies for Patients With Complex Congenital Heart Disease

The combination of critical pulmonary outflow obstruction with a large ventricular septal defect is symbolized by the diagnosis of tetralogy of Fallot, the most common form of cyanotic congenital heart disease. In many ways, the history of management for patients with tetralogy is representative of the evolution of management for all children with complex congenital cardiac diagnoses. Tetralogy was the first complex lesion addressed surgically with the palliative Blalock-Taussig shunt in 1945 and the first repaired completely with patients’ mothers serving as the bypass machine in 1954.1,2 The introduction of valved conduits in 1964 allowed repair of lesions not previously considered amenable to correction.3 The next 3 decades were marked by improved survival at open heart repair, recognition of the progressive deterioration of valved conduits necessitating early and repeated reoperation, and a progressive decrease in the age of primary repair to now the first few months of life.4,5 In the late 1970s, reports of arrhythmia and late sudden death among tetralogy survivors led to evaluation of tetralogy cohorts with residual right ventricular (RV) volume and/or pressure overload identified as predictors of late complications.6,7 Recognition of this problem heightened appreciation of the importance of arrhythmias in postoperative congenital heart disease patients and identified the need for informed long-term care and attention to residua of earlier procedures for all patients with congenital heart disease.8 Finally, the last 20 years have witnessed the dramatic rise in interventional procedures to address both correction of simple lesions and palliation/management of complex diagnoses.9 Article p 2598 The remarkable progress in care of children with tetralogy exemplifies the collaboration between pediatric cardiologists and congenital cardiac surgeons, the development of new techniques to address problems as they emerge, and the continuous evolution of management that have characterized care of all patients with …

Immunohistological findings for an extracardiac conduit in Fontan pathway constructed with pedicled autologous pericardium

Although autologous pericardium has been used in pedicled fashion for various reconstructive procedures in congenital cardiovascular surgery with the expectation that it will be able to grow and remain viable after implantation, no clinical study has evaluated the histological characteristics of implanted pedicled pericardium long after previous implantation. We describe herein histological findings of pedicled pericardium, which had been used for three years as an extracardiac conduit in Fontan pathway. A four-year-old boy with a history of Fontan operation using pedicled autologous pericardial roll required conduit replacement three years after the previous operation, and resected pericardial tissue was examined immunohistologically. Staining for CD34 revealed abundant microvasculature, suggesting preservation of viability. Staining for factor VIII demonstrated the presence of endothelium on the luminal surface of the conduit. Elastica-van Gieson staining revealed a band of elastic tissue, which is generally found not in the native pericardium but in the vascular wall structures. These findings suggested that the pedicled pericardium thus appeared to have remained viable and might have differentiated to resemble tissue of the vascular wall after having been used in Fontan pathway.